氟中英文翻译

氟中英文翻译（精选6篇）

篇1：氟中英文翻译

Fundamentals This chapter describes the fundamentals of today’s wireless communications.First a detailed description of the radio channel and its modeling are presented, followed by the introduction of the principle of OFDM multi-carrier transmission.In addition, a general overview of the spread spectrum technique, especially DS-CDMA, is given and examples of potential applications for OFDM and DS-CDMA are analyzed.This introduction is essential for a better understanding of the idea behind the combination of OFDM with the spread spectrum technique, which is briefly introduced in the last part of this chapter.1.1 Radio Channel Characteristics Understanding the characteristics of the communications medium is crucial for the appropriate selection of transmission system architecture, dimensioning of its components, and optimizing system parameters, especially since mobile radio channels are considered to be the most difficult channels, since they suffer from many imperfections like multipath fading, interference, Doppler shift, and shadowing.The choice of system components is totally different if, for instance, multipath propagation with long echoes dominates the radio propagation.Therefore, an accurate channel model describing the behavior of radio wave propagation in different environments such as mobile/fixed and indoor/outdoor is needed.This may allow one, through simulations, to estimate and validate the performance of a given transmission scheme in its several design phases.1.1.1 Understanding Radio Channels In mobile radio channels(see Figure 1-1), the transmitted signal suffers from different effects, which are characterized as follows: Multipath propagation occurs as a consequence of reflections, scattering, and diffraction of the transmitted electromagnetic wave at natural and man-made objects.Thus, at the receiver antenna, a multitude of waves arrives from many different directions with different delays, attenuations, and phases.The superposition of these waves results in amplitude and phase variations of the composite received signal.Doppler spread is caused by moving objects in the mobile radio channel.Changes in the phases and amplitudes of the arriving waves occur which lead to time-variant multipath propagation.Even small movements on the order of the wavelength may result in a totally different wave superposition.The varying signal strength due to time-variant multipath propagation is referred to as fast fading.Shadowing is caused by obstruction of the transmitted waves by, e.g., hills, buildings, walls, and trees, which results in more or less strong attenuation of the signal strength.Compared to fast fading, longer distances have to be covered to significantly change the shadowing constellation.The varying signal strength due to shadowing is called slow fading and can be described by a log-normal distribution [36].Path loss indicates how the mean signal power decays with distance between transmitter and receiver.In free space, the mean signal power decreases with the square of the distance between base station(BS)and terminal station(TS).In a mobile radio channel, where often no line of sight(LOS)path exists, signal power decreases with a power higher than two and is typically in the order of three to five.Variations of the received power due to shadowing and path loss can be efficiently counteracted by power control.In the following, the mobile radio channel is described with respect to its fast fading characteristic.1.1.2 Channel Modeling The mobile radio channel can be characterized by the time-variant channel impulse response h(τ , t)or by the time-variant channel transfer function H(f, t), which is the Fourier transform of h(τ , t).The channel impulse response represents the response of the channel at time t due to an impulse applied at time t − τ.The mobile radio channel is assumed to be a wide-sense stationary random process, i.e., the channel has a fading statistic that remains constant over short periods of time or small spatial distances.In environments with multipath propagation, the channel impulse response is composed of a large number of scattered impulses received over Np different paths，Where

and ap, fD,p, ϕp, and τp are the amplitude, the Doppler frequency, the phase, and the propagation delay, respectively, associated with path p, p = 0,..., Np − 1.The assigned channel transfer function is

The delays are measured relative to the first detectable path at the receiver.The Doppler Frequency

depends on the velocity v of the terminal station, the speed of light c, the carrier frequency fc, and the angle of incidence αp of a wave assigned to path p.A channel impulse response with corresponding channel transfer function is illustrated in Figure 1-2.The delay power density spectrum ρ(τ)that characterizes the frequency selectivity of the mobile radio channel gives the average power of the channel output as a function of the delay τ.The mean delay τ , the root mean square(RMS)delay spread τRMS and the maximum delay τmax are characteristic parameters of the delay power density spectrum.The mean delay is

Where

Figure 1-2 Time-variant channel impulse response and channel transfer function with frequency-selective fading is the power of path p.The RMS delay spread is defined as Similarly, the Doppler power density spectrum S(fD)can be defined that characterizes the time variance of the mobile radio channel and gives the average power of the channel output as a function of the Doppler frequency fD.The frequency dispersive properties of multipath channels are most commonly quantified by the maximum occurring Doppler frequency fDmax and the Doppler spread fDspread.The Doppler spread is the bandwidth of the Doppler power density spectrum and can take on values up to two times |fDmax|, i.e.，1.1.3Channel Fade Statistics The statistics of the fading process characterize the channel and are of importance for channel model parameter specifications.A simple and often used approach is obtained from the assumption that there is a large number of scatterers in the channel that contribute to the signal at the receiver side.The application of the central limit theorem leads to a complex-valued Gaussian process for the channel impulse response.In the absence of line of sight(LOS)or a dominant component, the process is zero-mean.The magnitude of the corresponding channel transfer function

is a random variable, for brevity denoted by a, with a Rayleigh distribution given by

Where

is the average power.The phase is uniformly distributed in the interval [0, 2π].In the case that the multipath channel contains a LOS or dominant component in addition to the randomly moving scatterers, the channel impulse response can no longer be modeled as zero-mean.Under the assumption of a complex-valued Gaussian process for the channel impulse response, the magnitude a of the channel transfer function has a Rice distribution given by

The Rice factor KRice is determined by the ratio of the power of the dominant path to thepower of the scattered paths.I0 is the zero-order modified Bessel function of first kind.The phase is uniformly distributed in the interval [0, 2π].1.1.4Inter-Symbol(ISI)and Inter-Channel Interference(ICI)The delay spread can cause inter-symbol interference(ISI)when adjacent data symbols overlap and interfere with each other due to different delays on different propagation paths.The number of interfering symbols in a single-carrier modulated system is given by

For high data rate applications with very short symbol duration Td < τmax, the effect of ISI and, with that, the receiver complexity can increase significantly.The effect of ISI can be counteracted by different measures such as time or frequency domain equalization.In spread spectrum systems, rake receivers with several arms are used to reduce the effect of ISI by exploiting the multipath diversity such that individual arms are adapted to different propagation paths.If the duration of the transmitted symbol is significantly larger than the maximum delay Td τmax, the channel produces a negligible amount of ISI.This effect is exploited with multi-carrier transmission where the duration per transmitted symbol increases with the number of sub-carriers Nc and, hence, the amount of ISI decreases.The number of interfering symbols in a multi-carrier modulated system is given by

Residual ISI can be eliminated by the use of a guard interval(see Section 1.2).The maximum Doppler spread in mobile radio applications using single-carrier modulation is typically much less than the distance between adjacent channels, such that the effect of interference on adjacent channels due to Doppler spread is not a problem for single-carrier modulated systems.For multi-carrier modulated systems, the sub-channel spacing Fs can become quite small, such that Doppler effects can cause significant ICI.As long as all sub-carriers are affected by a common Doppler shift fD, this Doppler shift can be compensated for in the receiver and ICI can be avoided.However, if Doppler spread in the order of several percent of the sub-carrier spacing occurs, ICI may degrade the system performance significantly.To avoid performance degradations due to ICI or more complex receivers with ICI equalization, the sub-carrier spacing Fs should be chosen as

such that the effects due to Doppler spread can be neglected(see Chapter 4).This approach corresponds with the philosophy of OFDM described in Section 1.2 and is followed in current OFDM-based wireless standards.Nevertheless, if a multi-carrier system design is chosen such that the Doppler spread is in the order of the sub-carrier spacing or higher, a rake receiver in the frequency domain can be used [22].With the frequency domain rake receiver each branch of the rake resolves a different Doppler frequency.1.1.5Examples of Discrete Multipath Channel Models Various discrete multipath channel models for indoor and outdoor cellular systems with different cell sizes have been specified.These channel models define the statistics of the 5 discrete propagation paths.An overview of widely used discrete multipath channel models is given in the following.COST 207 [8]: The COST 207 channel models specify four outdoor macro cell propagation scenarios by continuous, exponentially decreasing delay power density spectra.Implementations of these power density spectra by discrete taps are given by using up to 12 taps.Examples for settings with 6 taps are listed in Table 1-1.In this table for several propagation environments the corresponding path delay and power profiles are given.Hilly terrain causes the longest echoes.The classical Doppler spectrum with uniformly distributed angles of arrival of the paths can be used for all taps for simplicity.Optionally, different Doppler spectra are defined for the individual taps in [8].The COST 207 channel models are based on channel measurements with a bandwidth of 8–10 MHz in the 900-MHz band used for 2G systems such as GSM.COST 231 [9] and COST 259 [10]: These COST actions which are the continuation of COST 207 extend the channel characterization to DCS 1800, DECT, HIPERLAN and UMTS channels, taking into account macro, micro, and pico cell scenarios.Channel models with spatial resolution have been defined in COST 259.The spatial component is introduced by the definition of several clusters with local scatterers, which are located in a circle around the base station.Three types of channel models are defined.The macro cell type has cell sizes from 500 m up to 5000 m and a carrier frequency of 900 MHz or 1.8 GHz.The micro cell type is defined for cell sizes of about 300 m and a carrier frequency of 1.2 GHz or 5 GHz.The pico cell type represents an indoor channel model with cell sizes smaller than 100 m in industrial buildings and in the order of 10 m in an office.The carrier frequency is 2.5 GHz or 24 GHz.COST 273: The COST 273 action additionally takes multi-antenna channel models into account, which are not covered by the previous COST actions.CODIT [7]: These channel models define typical outdoor and indoor propagation scenarios for macro, micro, and pico cells.The fading characteristics of the various propagation environments are specified by the parameters of the Nakagami-m distribution.Every environment is defined in terms of a number of scatterers which can take on values up to 20.Some channel models consider also the angular distribution of the scatterers.They have been developed for the investigation of 3G system proposals.Macro cell channel type models have been developed for carrier frequencies around 900 MHz with 7 MHz bandwidth.The micro and pico cell channel type models have been developed for carrier frequencies between 1.8 GHz and 2 GHz.The bandwidths of the measurements are in the range of 10–100 MHz for macro cells and around 100 MHz for pico cells.JTC [28]: The JTC channel models define indoor and outdoor scenarios by specifying 3 to 10 discrete taps per scenario.The channel models are designed to be applicable for wideband digital mobile radio systems anticipated as candidates for the PCS(Personal Communications Systems)common air interface at carrier frequencies of about 2 GHz.UMTS/UTRA [18][44]: Test propagation scenarios have been defined for UMTS and UTRA system proposals which are developed for frequencies around 2 GHz.The modeling of the multipath propagation corresponds to that used by the COST 207 channel models.HIPERLAN/2 [33]: Five typical indoor propagation scenarios for wireless LANs in the 5 GHz frequency band have been defined.Each scenario is described by 18discrete taps of the delay power density spectrum.The time variance of the channel(Doppler spread)is modeled by a classical Jake’s spectrum with a maximum terminal speed of 3 m/h.Further channel models exist which are, for instance, given in [16].1.1.6Multi-Carrier Channel Modeling Multi-carrier systems can either be simulated in the time domain or, more computationally efficient, in the frequency domain.Preconditions for the frequency domain implementation are the absence of ISI and ICI, the frequency nonselective fading per sub-carrier, and the time-invariance during one OFDM symbol.A proper system design approximately fulfills these preconditions.The discrete channel transfer function adapted to multi-carrier signals results in

where the continuous channel transfer function H(f, t)is sampled in time at OFDM symbol rate s and in frequency at sub-carrier spacing Fs.The duration

s is the total OFDM symbol duration including the guard interval.Finally, a symbol transmitted onsub-channel n of the OFDM symbol i is multiplied by the resulting fading amplitude an,i and rotated by a random phase ϕn,i.The advantage of the frequency domain channel model is that the IFFT and FFT operation for OFDM and inverse OFDM can be avoided and the fading operation results in one complex-valued multiplication per sub-carrier.The discrete multipath channel models introduced in Section 1.1.5 can directly be applied to(1.16).A further simplification of the channel modeling for multi-carrier systems is given by using the so-called uncorrelated fading channel models.1.1.6.1Uncorrelated Fading Channel Models for Multi-Carrier Systems These channel models are based on the assumption that the fading on adjacent data symbols after inverse OFDM and de-interleaving can be considered as uncorrelated [29].This assumption holds when, e.g., a frequency and time interleaver with sufficient interleaving depth is applied.The fading amplitude an,i is chosen from a distribution p(a)according to the considered cell type and the random phase ϕn,I is uniformly distributed in the interval [0,2π].The resulting complex-valued channel fading coefficient is thus generated independently for each sub-carrier and OFDM symbol.For a propagation scenario in a macro cell without LOS, the fading amplitude an,i is generated by a Rayleigh distribution and the channel model is referred to as an uncorrelated Rayleigh fading channel.For smaller cells where often a dominant propagation component occurs, the fading amplitude is chosen from a Rice distribution.The advantages of the uncorrelated fading channel models for multi-carrier systems are their simple implementation in the frequency domain and the simple reproducibility of the simulation results.1.1.7Diversity The coherence bandwidth of a mobile radio channel is the bandwidth over which the signal propagation characteristics are correlated and it can be approximated by

The channel is frequency-selective if the signal bandwidth B is larger than the coherence bandwidth.On the other hand, if B is smaller than , the channel is frequency nonselective or flat.The coherence bandwidth of the channel is of importance for evaluating the performance of spreading and frequency interleaving techniques that try to exploit the inherent frequency diversity Df of the mobile radio channel.In the case of multi-carrier transmission, frequency diversity is exploited if the separation of sub-carriers transmitting the same information exceeds the coherence bandwidth.The maximum achievable frequency diversity Df is given by the ratio between the signal bandwidth B and the coherence bandwidth，The coherence time of the channel is the duration over which the channel characteristics can be considered as time-invariant and can be approximated by

If the duration of the transmitted symbol is larger than the coherence time, the channel is time-selective.On the other hand, if the symbol duration is smaller than , the channel is time nonselective during one symbol duration.The coherence time of the channel is of importance for evaluating the performance of coding and interleaving techniques that try to exploit the inherent time diversity DO of the mobile radio channel.Time diversity can be exploited if the separation between time slots carrying the same information exceeds the coherence time.A number of Ns successive time slots create a time frame of duration Tfr.The maximum time diversity Dt achievable in one time frame is given by the ratio between the duration of a time frame and the coherence time, A system exploiting frequency and time diversity can achieve the overall diversity

The system design should allow one to optimally exploit the available diversity DO.For instance, in systems with multi-carrier transmission the same information should be transmitted on different sub-carriers and in different time slots, achieving uncorrelated faded replicas of the information in both dimensions.Uncoded multi-carrier systems with flat fading per sub-channel and time-invariance during one symbol cannot exploit diversity and have a poor performance in time and frequency selective fading channels.Additional methods have to be applied to exploit diversity.One approach is the use of data spreading where each data symbol is spread by a spreading code of length L.This, in combination with interleaving, can achieve performance results which are given for

by the closed-form solution for the BER for diversity reception in Rayleigh fading channels according to [40]

Whererepresents the combinatory function，and σ2 is the variance of the noise.As soon as the interleaving is not perfect or the diversity offered by the channel is smaller than the spreading code length L, or MCCDMA with multiple access interference is applied,(1.22)is a lower bound.For L = 1, the performance of an OFDM system without forward error correction(FEC)is obtained, 9

which cannot exploit any diversity.The BER according to(1.22)of an OFDM(OFDMA, MC-TDMA)system and a multi-carrier spread spectrum(MC-SS)system with different spreading code lengths L is shown in Figure 1-3.No other diversity techniques are applied.QPSK modulation is used for symbol mapping.The mobile radio channel is modeled as uncorrelated Rayleigh fading channel(see Section 1.1.6).As these curves show, for large values of L, the performance of MC-SS systems approaches that of an AWGN channel.Another form of achieving diversity in OFDM systems is channel coding by FEC, where the information of each data bit is spread over several code bits.Additional to the diversity gain in fading channels, a coding gain can be obtained due to the selection of appropriate coding and decoding algorithms.中文翻译 1基本原理

这章描述今日的基本面的无线通信。第一一个的详细说明无线电频道，它的模型被介绍，跟随附近的的介绍的原则的参考正交频分复用多载波传输。此外，一个一般概观的扩频技术，尤其ds-cdma，被给，潜力的例子申请参考正交频分复用，DS对1。分配的通道传输功能是

有关的延误测量相对于第一个在接收器检测到的路径。多普勒频率

取决于终端站，光速c，载波频率fc的速度和发病路径分配给速度v波αp角度页具有相应通道传输信道冲激响应函数图1-2所示。

延迟功率密度谱ρ（τ）为特征的频率选择性移动无线电频道给出了作为通道的输出功能延迟τ平均功率。平均延迟τ，均方根（RMS）的时延扩展τRMS和最大延迟τmax都是延迟功率密度谱特征参数。平均时延特性参数为

有

图1-2时变信道冲激响应和通道传递函数频率选择性衰落是权力页的路径均方根时延扩展的定义为 同样，多普勒频谱的功率密度（FD）的特点可以定义

在移动时变无线信道，并给出了作为一种金融衍生工具功能的多普勒频率通道输出的平均功率。多径信道频率分散性能是最常见的量化发生的多普勒频率和多普勒fDmax蔓延fDspread最大。多普勒扩散是功率密度的多普勒频谱带宽，可价值观需要两年时间| fDmax|，即

1.1.3频道淡出统计

在衰落过程中的统计特征和重要的渠道是信道模型参数规格。一个简单而经常使用的方法是从假设有一个通道中的散射，有助于在大量接收端的信号。该中心极限定理的应用导致了复杂的值的高斯信道冲激响应过程。在对视线（LOS）或线的主要组成部分的情况下，这个过程是零的意思。相应的通道传递函数幅度

是一个随机变量，通过给定一个简短表示由瑞利分布，有

是的平均功率。相均匀分布在区间[0，2π]。

在案件的多通道包含洛杉矶的或主要组件除了随机移动散射，通道脉冲响应可以不再被建模为均值为零。根据信道脉冲响应的假设一个复杂的值高斯过程，其大小通道的传递函数A的水稻分布给出

赖斯因素KRice是由占主导地位的路径权力的威力比分散的路径。I0是零阶贝塞尔函数的第一阶段是一致kind.The在区间[0，2π]分发。

1.1.4符号间（ISI）和通道间干扰（ICI）

延迟的蔓延引起的符号间干扰（ISI）当相邻的数据符号上的重叠与互相不同的传播路径，由于不同的延迟干涉。符号的干扰在单载波调制系统的号码是给予

对于高数据符号持续时间很短运输署<蟿MAX时，ISI的影响，这样一来，速率应用，接收机的复杂性大大增加。对干扰影响，可以抵消，如时间或频域均衡不同的措施。在扩频系统，与几个臂Rake接收机用于减少通过利用多径分集等，个别武器适应不同的传播路径的干扰影响。

如果发送符号的持续时间明显高于大的最大延迟运输署蟿最大，渠道产生ISI的微不足道。这种效果是利用多载波传输的地方，每发送符号的增加与子载波数控数目，因此，ISI的金额减少的持续时间。符号的干扰多载波调制系统的号码是给予

可以消除符号间干扰由一个保护间隔（见1.2节）的使用。

最大多普勒在移动无线应用传播使用单载波调制通常比相邻通道，这样，干扰对由于多普勒传播相邻通道的作用不是一个单载波调制系统的问题距离。对于多载波调制系统，子通道间距FS可以变得非常小，这样可以造成严重的多普勒效应ICI的。只要所有子载波只要是一个共同的多普勒频移金融衍生工具的影响，这可以补偿多普勒频移在接收器和ICI是可以避免的。但是，如果在对多普勒子载波间隔为几个百分点的蔓延情况，卜内门可能会降低系统的性能显着。为了避免性能降级或因与ICI卜内门更复杂的接收机均衡，子载波间隔财政司司长应定为

这样说，由于多普勒效应可以忽略不扩散（见第4章）。这种方法对应于OFDM的1.2节中所述，是目前基于OFDM的无线标准遵循的理念。

不过，如果多载波系统的设计选择了这样的多普勒展宽在子载波间隔或更高，秩序是在频率RAKE接收机域名可以使用[22]。随着频域RAKE接收机每个支部耙解决了不同的多普勒频率。

1.1.5多径信道模型的离散的例子

各类离散多与不同的细胞大小的室内和室外蜂窝系统的信道模型已经被指定。这些通道模型定义的离散传播路径的统计信息。一种广泛使用的离散多径信道模型概述于下。造价207[8]：成本207信道模型指定连续四个室外宏蜂窝传播方案，指数下降延迟功率密度谱。这些频道功率密度的离散谱的实现都是通过使用多达12个频道。与6频道设置的示例列于表1-1。在这种传播环境的几个表中的相应路径延迟和电源配置给出。丘陵地形导致最长相呼应。

经典的多普勒频谱与均匀分布的到达角路径可以用于简化所有的频道。或者，不同的多普勒谱定义在[8]个人频道。207信道的成本模型是基于一个8-10兆赫的2G，如GSM系统中使用的900兆赫频段信道带宽的测量。造价231[9]和造价259[10]：这些费用是行动的延续成本207扩展通道特性到DCS1800的DECT，HIPERLAN和UMTS的渠道，同时考虑到宏观，微观和微微小区的情况为例。空间分辨率与已定义的通道模型在造价259。空间部分是介绍了与当地散射，这是在基站周围设几组圆的定义。三种类型的通道模型定义。宏细胞类型具有高达500〜5000米，载波频率为900兆赫或1.8 GHz的单元尺寸。微细胞类型被定义为细胞体积约300米，1.2 GHz或5 GHz载波频率。细胞类型代表的Pico与细胞体积小于100工业建筑物和办公室中的10 m阶米室内信道模型。载波频率为2.5 GHz或24千兆赫。造价273：成本273行动另外考虑到多天线信道模型，这是不是由先前的费用的行为包括在内。

CODIT [7]：这些通道模型定义的宏，微，微微蜂窝和室外和室内传播的典型案例。各种传播环境的衰落特性是指定的在NakagamiSS）的不同扩频码L是长度，如图1-3所示的系统。没有其他的分集技术被应用。QPSK调制用于符号映射。移动无线信道建模为不相关瑞利衰落信道（见1.1.6）。由于这些曲线显示，办法，AWGN信道的一对L时，对MC-SS系统性能有很大价值。

另一种实现形式的OFDM系统的多样性是由前向纠错信道编码，在这里，每个数据位的信息分散在几个代码位。附加在衰落信道分集增益，编码增益一个可因适当的编码和解码算法的选择。

篇2：氟中英文翻译

蓄电池 battery 充电 converter 转换器 charger

开关电器 Switch electric 按钮开关 Button to switch 电源电器 Power electric 插头插座 Plug sockets

篇3：氟中英文翻译

1 Materials and methods

1.1 Materials

A total of 126 clinical strains of N.gonorrhoeae were isolated from June 2000 to June 2006 from urogenital tract of outpatients in Xiangya Hospital,Department of Microbiology of Xiangya Medical School,Central South University and the Center for Sexually Transmitted Disease Control and Prevention in Hunan province,P.R.China.

Standard stains of N.gonorrhoeae ATCC49266and ATCC 19424 were kindly provided by Gan Shangliu,Department of Microbiology,the Chinese U-niversity of Hongkong.ATCC49266 was used as quality control strain and ATCC 19424 was used as wildtype reference strains.

Disk of Ofloxacin,Lomefloxacin,Fleroxacin and Enoxacin were purchased from Tiantan Biological and Pharmaceutical Co.Ltd.,Beijing.T-M medium and G-C agar were obtained from OXOID,United Kingdom;E-test strips of Ciprofloxacin were purchased from AB-Bidisk,Sweden.Oxidase agents came from E.merck,Germany.The primers were synthesized by the Sangon company(Shanghai);and other biochemical agents such as pfu DNA polymerase,dNTPs and DNA markers were from Shanghai Sangon Company.

1.2 Methods

1.2.1 Collection and identification of clinical iso-lates

The specimens were taken from 3 to 4 cm inside the urethra of male patients and 1 to 1.5 cm inside the cervix of female patients.All samples were immediately inoculated into T-M medium.Plates were incubated at 35℃in 5%CO2for 24 to 36 h.All cultures were then subcultured into GC agars for one or two times.These isolates were identified by colony morphology,oxidase test and sugar utilization patterns and stored at-70℃in de-fatted milk until they were tested.

1.2.2 Disk diffusion test

Disk diffusion test to four Fluoroquinolones were performed according to the criteria of National guide to clinical laboratory procedures(third edition).Briefly,The gonococcal isolates were passaged for several times in nonselective media.N.gonorrhoeae colonies were suspended to the turbidity of a 0.5 McFarland standard in broth,and inoculated on GC agar plate with 1%defined supplement.Fluoroquinolone disks were applied on the plate.The plates were incubated at 35℃in 5%CO2for 20 to 24h.Zone diameters were read using a small-millimeter ruler specially designed for reading from the top surface of the plate.Interpretations of the zone diameters were according to the CLSI recommendations.

1.2.3 Determination of MIC of Ciprofloxacin by E-test

The E-test was applied to determine the MIC of Ciprofloxacin following the manufacturer′s instructions.Medium and bacteria suspensions were prepared as the disk diffusion test.The plates were streaked three times in different directions,with a sterile cotton swab which had been dipped in the above prepared suspension.After 15-minute drying,E test strips of Ciprofloxacin were applied onto the dry surface of plates.The plates were incubated at 35℃in 5%CO2for 20 to 24 h.The MICs were read at the point of intersection of the growth ellipse margin with the scale on the strip.According to the guideline of the CLSI[7],the strains were labelled as susceptible(MIC≤0.06μg/mL),intermediate resistant(MIC 0.12 to 0.5μg/mL),and resistant(MIC≥1μg/mL).

1.2.4 Amplification of QRDR in gyrA and parC genes with PCR

The DNA templates were prepared according to the method described by Ison[8].The sequences of gyrA and parC genes in N.gonorrhoeae were obtained from GenBank(accession number U08817 and U08907).The primers were designed by the Primer Premier 5.0 software,and their specificity was determined by the BLAST analysis in Internet.To amplify gyrA gene including QRDR,the forward and reverse primers were 5′-16ATC CGC CAC GAC CAC AAA T34-3′and 5′-364CGT CCA CCG ATC CGA AGT T346-3′,and the expected length of product was349 bp.To amplify parC gene including QRDR,the forward and reverse primers were 5′-15GCA CGC TTC CCA TAC CGA32-3′and 5′-443TCC ACC GTC CCC TGA TTG426-3′,and the expected length of product was 429 bp.We named the two fragment gyrA349and parC429respectively.PCR amplifications were performed in a Perkin-Elmer Thermal Cycle System(Model 480)in a total volume of 50μL.The reaction mixture contained 5μL of 10×Buffer,5μL of 2mmol/L dNTPs,5μL of 2μmol/L each primer,5μL of DNA templates,3μL of 25mmol/L MgCl2,2.5μL of 1 U/μL Pfu DNA polymerase,and 19.5μL of sterile triple distilling water.PCR amplification conditions consisted of 35 cycles at 94℃for 60 seconds,59℃for50 seconds,72℃for 55 seconds,and a final extention at 72℃for 5 minutes after an initial denaturation at94℃for 5 minutes.The reaction mixture which didn′t contain primer or template was used as negative control,and wild-type standard stain ATCC19424 was used as positive control.The PCR products were determined by 1.5%agarose gel electrophoresis,visualized by ultraviolet transillumination,scanned and photographed by a scientific imagining system(EA-GER EYETM,United States).

1.2.5 DNA sequencing and sequence analysis

The gyrA349and parC429gene fragments in ATCC19429and 21 clinical isolates which were simultaneously sensitive,intermediative or resistant to five fluoroquinolones were sequenced.The reference strains were sequenced by forward and reverse primers and the clinical isolates were sequenced only by forward primer.Sequencing was performed by an ABI-Prism377 sequencer in Bioasia Biology Techniques Company(Shanghai).Sequence comparisons were performed at website:http://www.ncbi.nlm.nih.gov/BLAST/.

2 Results

2.1 Results of antimicrobial susceptibilities in clinical isolates

The percentages of resistance to Ofloxacin,Fleroxacin,Lomefloxacin,and Enoxacin were 70.6%,81.7%,72.2%and 82.5%respectively in 126 clinical isolates.Range of Ciprofloxacin MICs was 0.004～12.0μg/mL in 63 strains.5 isolated strains were susceptible to Ciprofloxacin,17 were intermediate and 41were resistant.The disc diffusion test showed that the numbers of strains simultaneously sensitive,intermediate and resistant to Ciprofloxacin,Ofloxacin,Lomefloxacin,Fleroxacin and Enoxacin were 5,4 and 39respectively.And 5,4 and 12 strains were selected to sequence analysis among them respectively.

2.2 Results of PCR amplification

As we expected,349 bp and 429 bp fragments were found in the PCR amplification products in all clinical isolates and standard strain and there wasn′t nonspecific amplified band.The results were showen in Figure 1 and 2.

Lane l～5:clinical isolates;lane 6:positive control;Lane 7:negative control;lane 8:Puc19DNA/MSPI marker

Lane l～5:clinical isolates;lane 6:positive control;Lane 7:negative control;lane 8:Puc19DNA/MSPI marker

2.3 Results of sequence analysis of gyrA349and parC429

The sequences of gyrA349fragments of 5 clinical susceptible isolates to fluoroquinolones and wide-type ATCC19424 strain were identical to the sequence provided by Genbank.Mutations were found in 16clinical isolates which were intermediate or resistant to Fluoroquinolones.The two strains with MICs from0.064 to 0.094μg/mL carried a single point mutation,while the 14 strains with MICs≥0.25μg/mL contained double-point mutations.Of all the 16strains containing mutations,15 strains exhibited substitution of Ser 91(TCC)→Phe(TTC).

Note;-:no mutation

In 9 clinical isolates with MICs≤0.5μg/mL whichweresensitiveorintermediateto Fluoroquinolones and wild-type ATCC19424 strain,except one clinical strain contained silent mutation at codon 104 and 131,the other sequences were idendical to the sequence provided by Genbank.While all 12 isolates with MICs≥1.0μg/mL had mutations in parC gene and most substitutions were at codon 85 to 91 sites.Furthermore,these strains carried double-point mutations in gyrA gene as well.The results were showen in the Table.

3 Discussion

Fluoroquinolones were recommended as the first line agents for the treatment of uncomplicated gonorrhea by World Health Organization(WHO)and the Centers for Disease Control and Prevention(CDC).However,with the wide use of these agents,susceptibilities to fluoroquinolones in N.gonorrhoeae are decreasing and reports of therapeutic failure are increasing in recent years[9～11].Investigation of the WHO Western Pacific Gonococcal Antimicrobial Surveillance Programme(GASP)showed that quinolone-resistant N.gonorrhoeae(QRNG)were found in all countries and areas attending this program.Moreover,rate and level of resistance had been stepwise increasingly[1～3].In our study,more than 65.1%isolates were resistant to Fluoroquinolones and 61.9%isolates were resistant to all five detected Fluoroquinolones simultaneously.So,it was evident that Fluoroquinolones could not be used as the first-line agents for the treatment of gonorrhea in Changsha,P.R.China.

Fluoroquinolones resistance in gram negative bacteria is closely associated with the mutations in gyrA and parC genes[12].In E.coli,the DNA sequences which are correlated with Fluoroquinolone resistance in gyrA gene(encode DNA gyrase)and parC gene(encode topoisomease IV)are named quinolone resistancedetermining region(QRDR).Mutations in QRDR often changed structure of DNA gyrase and topoisomease IV and resulted in resistance to Fluoroquinolones[13,14].In1994,Belland[15](United States)sequenced gyrA gene and parC gene of N.gonorrhoeae first and found that DNA sequences of gyrA gene and parC gene had 52%and 47%homology with those of E.coli,respectively.A fluoroquinolone-susceptible N.gonorrhoeae,FA-19,was induced by Ciprofloxacin.And then one or more substitutions were found in these less-susceptible or resistant strains in GyrA and ParC.Ilina EN reported that Fluoroquinolone resistance in clinical isolates was associated with mutations in gyrA gene and parC gene,similar to laboratory mutant strains[16].

Of the 21 N.gonorrhoeae strains with DNA sequencing,5 Fluoroquinolone-susceptible strains contained no mutation,while 16 intermediate or resistant strains contained mutations in gyrA gene,and some contained mutations in parC gene simultaneously.The MICs of Ciprofloxacin for the strains with Ser-91-to-Try or Ser-91-to-Phe substitutions in GyrA increased 16 or 24-fold comparing with those for wildtype strains.The MICs of Ciprofloxcin for the strains with double-point mutations in GryA(ser 91,Asp 95)increased 63 folds comparing with those for the wildtype strains and all the MICs were more than 0.25μg/mL.These results indicated that the mutations in gyrA gene had close relationship with the resistance to Fluoroquinolones in N.gonorrhoeae.The level of resistance would be promoted when the number of the mutations increased.Strains with MICs between 0.064 to0.094μg/mL carried a one-point mutation in gyrA gene while the strains with MICs≥0.25μg/mL contained double-point mutations in gyrA gene.In addition,the strains with MICs≥1.0μg/mL exhibited a single or double-point mutations in parC gene except for doublepoint mutations in gyrA gene.Their MICs were 4 to 48-fold higher than those of double-point mutations in gyrA gene and 250 to 3 000-fold higher than that of wildtype strain.All these suggested that Fluoroquinolone resistance in clinical isolates of N.gonorrhoeae was closely associated with the gradual mutations in gyrA gene and parC gene.Mutations within gyrA gene mediated low and moderate levels of Fluoroquinolone resistance,while mutations in parC gene would promote the level of resistance to Fluoroquinolones.

篇4：浅析中英文商标的翻译

关键词：中英文商标翻译跨文化交际

商标是商品的生产者、经营者在其生产、制造、加工、挑选、经销的商品上，或者服务的提供者在其提供的服务上所采用的标识。它是现代社会经济发展的产物，代表着企业的无形资产，对企业成长及对外发展有着极其重要的作用。因此，商品在进入国外市场时，商标的翻译就变得非常重要。如果在商标的翻译过程中考虑不全面，仅仅通过字面意思或者简单的音译，往往会成为翻译的败笔，最终导致该商品在市场中的全面溃败。

在日常生活中，我们会发现很多英文商标的翻译都是音译，这是因为在中文中。没有与该商标相对应的汉语。为了适应中国顾客的阅读习惯，译者通常会选用简单美观、琅琅上口，一看到就能联想到商品的一些汉字组合。这其中最成功的英文翻译就是“coca－cola”，中文翻译为“可口可乐”。这个翻译不仅贴合英文发音，而且还让人联想到这种饮料的可口，以及喝了之后顾客的情绪。

英国著名零售商TESCO也是一个极好的翻译例子。1924年，TESCO创始人杰克·科恩(Jack cohen)开始从事食品批发销售业务，并创立了TESCO的品牌来标识自己出售的产品。TESCO这个名字来源于杰克一个合作商(T.E Stock well)名字的前三位首写字母和自己姓氏(Co－hen)的前两位首写字母，杰克就用这个新单词“TESCO”作为自己经营商品的商标，并准备创立以“TESCO”为名的食品零售商店。2005年，TESCO入驻中国，TESCO的中文翻译也定为“乐购”，这一翻译正好契合了TESCO的特性——高高兴兴地购物，而且其中文发音与英文发音也很相符。

当然还存在很多不完全符合发青的例子。比如世界著名计算机软件开发商微软公司Mi－crosoft，它的翻译简单大胆，没有任何音译的成分，但是却把它相对应的中文意思翻译出来了，语言就是这么神奇。它采用了英文直译成中文的方法。“micro”本意是微小的，“soft”本意是软的，两个形容词就这么组合成了一个名词——微软，另外一个不符合音译的例子是宝洁公司旗下著名的洗发水品牌Rejoice，它在英语中的翻译是“高兴、喜悦”，而宝洁套司采用的翻译却是“飘柔”：“飘”的意思是随风飞动，我们常用的词语有飘扬、飘逸、飘浮等；“柔”则有软、温和等意思。而“飘柔”这一词完全表选出了用完产品后头发柔顺和飘选的感觉，合情合理。现在有很多翻译家更倾向于品牌直译，这样更能表达出该产品的本地特色。

在中国也有很多商标的翻译直接采用音译，这些翻译有些代表了中国商品的特点和中国特色。比较成功的翻译有很多，比如小天鹅洗衣机翻译为“Little Swan”，长城电风扇翻译为“Great Wall”，太平鸟衬衣译为“Peace Bird”等。

如果音译不成，就要首先考虑意译了。在意译的时候，我们需要充分考虑两种语言的文化背景、民情风俗、宗教信仰等，翻译要既简洁、形象、生动，又符合顾客的购物习惯。一个成功的例子就是中国第一个生产药妆的企业伽蓝集团旗下的药妆品牌——医婷Insea，“Insea”来源于大海，浩瀚的海洋蕴含着丰富的资源和能量。翻译中，“in”音译为医，表明了产品是一种药妆，“sea”意译为婷，符合中国女性渴望亭亭玉立的美好愿望，近年来该产品以自然健康的形象深受顾客的喜爱。

篇5：中英文翻译复习

1.我学过英语、历史、哲学和打字等课程。

I took English,history,philosophy,typing and some other subject.2.很明显，上学是每一个孩子的梦想，而辍学则是一场噩梦。

Obviously, going to school is every child’s dream , an quitting school is their nightmare.3.考察对能否完成任务，没人会真的知道。

Whether the research team will accomplish the task ro not, nobody really knows.4.她是不是在说实话，没有人会真的知道。

Whether she is telling the truth or not ,nobody really knows.5.我最近几年里一直没有听到她的消息。

I haven’t heard from her in the past few years.6.将在到达后即刻告知。

Will be informed upon arrival.7.但是，资金成了叫人头疼的事。

However, money provse to be a big headache.8.对他们来说，掌握实用技能比记忆更重要。

To them, learning practical skills is even harder then memorizing knowledge.9.对她来说，取得实际工作经验比挣钱更重要。

To her , getting practical work experience is even more important than making money.10.这个公司的职员都有较好的个人素质。

The staff of this company have quite good personal qualities.11.她想毕业后到国外深造。我也想。

She wants to further her study abroad after graduation.So do I.12.这个消息使得这个老板很困惑。

The news makes the boss puzzled.13.多媒体教师在现代化学校中很常见。

Multi-media classrooms are very common in modern schools.14.学生赚取零用钱最常见的地方就是打零工。

The most popular way for a student to earn extra money is to a part-time job.15.年轻人要理解父母最好的方法就是与他们交流。

The best way for young people to understand their parents is to communicate with them.16.这次度假当然会很美妙，不过得有人接替我的工作。

It’ll be a wonderful holiday ,of course, but somebody has to take my job.17.历史是人民创造的。

History is created by people.18.他头一碰到枕头就会睡着。

He will fall asleep as soon as his head touches the pillow.19.然而，如果我们没有足够的勇气，这个计划将会彻底失败。

However, if we do not have enough courage, the plan may prove to be a complete failure.20.所以年轻人要养成习惯，不要事事依靠父母。

Therefore, young people should make it a rule not to depend ong parents for everything.21.如果你在大街上走失，不要迟疑快寻求帮助。

If you find yourself lost in the street , don’t hesitate to ask for help.22.这台计算机是昨天购买的。This computer was bought yesterday.23.如果你还没有下决心，为什么不跟朋友讨论一下这件事呢。

If you haven’t yet made up your mind, why not discuss it with your friends.24.It is the responsibility of the parents to make sure that the children receive good education.保证子女受到良好的教育是父母的责任。25.Please remain silent and keep the books closed.请安静，不要打开书。

26.请坐在那里别动，不要开窗。

Please remain seated an keep the windows shut.27.I would like to ask my supervisor to write a reference letter for me.我想请我的导师为我写一封推荐信。

28.我想请几个朋友过来参加晚宴，庆祝我的生日。

I’d like to have a few friends over for a dinner party to celebrate my birthday.29.主人期望我们六点到。

The host expects us to arrive at six.30.一旦你做出了承诺，你最好不要食言。

Once you have made a promise, it is better not to break your words.31.但是，西方人认为谈论别人的私事是不礼貌的。

However, all of all of us find being kept waiting for more than ten minutes unbearable.32.说起名片，你应该用双手递。

And when it comes to business cards, you should present them with two hands.33.请吃海参。趁热吃。

Help yourself to the sea-cucumber.Eat it while it’s hot.34.People live and die but life continues.人有生有死，但生活仍在继续。35.太阳升起又落下，但日子在继续。

The sun rises an sets, but days go on.36.如果想表达合作的意愿，你最好亲自去趟公司。

If you want to show your willingness to cooperate, you’d better go to the company in person.37.我们这座城市因其古建筑而世界闻名。

Our city is world-famous for its old buildings.38.Tank you very much for inviting me to your home on the weekend.非常感谢你请我周末到贵府做客。

39.很感谢你邀请我们后天去参加你的生日聚会。

Thank you very much for inviting us to your birthday party the day after tomorrow.40.Don’t spit in public places ,since that will be deemed ill-mannered.不要在公共场合吐痰，因为那样被认为是没有教养的。41.不然的话，顾客可能会失去对我们产品的兴趣。

Otherwise, it is likely that the customers will lose their interest in our products.42.有的家长孩子要啥就给买啥。

篇6：氟中英文翻译

传递语言 更传递竞争的力量

英文合同翻译价格 英文合同翻译需要多少钱

在企业的经营过程中，有时候可能会涉及到翻译这个问题，但是一般的小企业并没有专门的人去做这件事情，大部分都是外包。那么对于企业来讲，翻译一份英文合同需要多少钱呢？作为浙江省最大的翻译公司，以琳翻译就在这里为大家解读一下。

一般来讲，翻译这项服务都是以字数来计价的，市场上的一般的价格是50-80元/千字，这是一个基本的价格。但是不同的公司的专业性质不一样的话，所给出的价格也是不一样的。对于公司的衡量标准来讲，影响价格的因素主要有：公司的资历、翻译人员的专业性、翻译文件的种类、难度等。所以，如果你需要去找翻译公司去服务，那么就需要考虑这些方面的东西。而对于合同这种文件，对于公司来讲是十分重要的，所以也需要去找专业的公司去进行翻译，如果是找一个资质不够的公司或者团队，那么就可能产生一些意想不到的问题，从而影响到公司的最终利益。

下面，我们来看看以琳翻译给出的翻译的价格。

从上面的价格可以看出，以琳翻译给出的价格是高于一般市场上的价格的，最低级别的翻译是160元/千字，然后分为A、B、C三级。C级译稿为普通中籍译员+中籍译员审核，满足客户对译文的普通要求。这是对于一般的合同而言的，但是如果是部分专业性质较强或者要求比较高的译文的话，那么可以选择更高级别的翻译，当然价格还是相对比较高的。

那么以琳翻译的资质是怎么样呢？我们再来看一下。

杭州以琳翻译有限公司是浙江省最大的实体翻译公司、中国翻译协会单位会员、美国翻译协会会员、全国翻译专业硕士研究生教育实习基地、西博会指定合作伙伴、以琳杭州翻译公司翻译团队成员均具有五年以上专业翻译、项目管理经验，绝大部分成员具有十年以上行业翻译经验。翻译服务涵盖英语、法语、韩语、日语、德语、俄语、西班牙语、葡萄牙语、（）以琳翻译

传递语言 更传递竞争的力量

意大利语、希腊语、荷兰语、阿拉伯语、波斯语、印尼语、土耳其语、蒙古语、越南语、印地语、乌尔都语、马来语和塞尔维亚语等30多个语种，业务遍及国内主要城市和部分国际性大都市。而同样拥有这样的资质的翻译公司，通过对网络上报价的调查，最低的翻译价格也达到200元/千字左右，所以，通过对比来讲，以琳翻译的价格是性价比十分高的。