单种的

One was the pqsA' positive expression plasmid constructed by cloning the pqsA'-lacZ fusion digested from pYHP441 into miniCTX-1, whose sequence was then integrated into wild type PAO-1 chromosome by biparental mating procedure. The other was pqsA-E operon knock-out plasmid whose sequence between pqsD and pqsE operon was inserted by tetracycline cassette by the site specific insertion mutagenesis strategy and the mutant constructed by biparental mating of S17-1 that harbored the plasmid and pqsA' positive expression mutant.

一种是酶切质粒pYHP441获得pqsA'-lacZ片段后，亚克隆入质粒miniCTX-1中，构建成PqsA'的阳性表达质粒，随后将构建的质粒，通过双亲交配过程整合入野生型铜绿假单胞菌株PAO-1染色体组中；另一种是通过点特异插入诱变策略，将四环素基因盒插入启动子pqsD和pqsE之间，构建的阴性质粒转化入大肠杆菌S17-1株后，和上述pqsA'阳性表达突变株进行双亲交配过程。

It can support broadcast, multicast and unicast,and it can support the communication of multiplicate messages.

文章提出了一种基于服务器转发的通讯协议，其能够支持广播、组播、单播这几种通讯方式，支持多种类型消息的通信，并介绍了该协议的功能、报文格式以及实现方法。

Their corrosion inhibition action of stainless steel in hydrofluoric acid is studied by adsorption theory and electrochemical polarization-curve method,the mechanism of corrosion inhibition action is analyzed.the result shows that the single molecule layer of these compounds is adsorbed on the surface of the stainless steel and followed Langmuir isothermal equation. the adsorption procedure of propiolic alcohol is endothermic reaction, the adsorption ability and corrosion inhibition efficiency increased when temperature rised. The adsorption procedure of other three compounds are all exothermic reaction , the adsorption ability and corrosion inhibition efficiency decreased when temperature increased.

实验结果表明：这几种物质在不锈钢表面产生单分子层吸附，并且满足Langmuir吸附规律，丙炔醇的吸附过程为吸热反应，随着温度的升高，吸附能力增强，缓蚀率升高；其它三种化合物的吸附过程均为放热反应，温度升高，吸附能力下降，缓蚀率降低。

The results were as follows: 1 There were 7 133 trees, belonging to 23 species and 18 genera and 13 families, and their average DBH, crown and height were respectively 27.59 cm, 4.10 m and 6.94 m. In general their average crown was relative small. 2 S, H (Shannon-Wiener index), and D of biodiversity index were small, and there were the obvious difference in those indexes among different streets, which suggested that there were certain monotone of the tree species and structure layer. 3 The dominant species mainly consisted of evergreen trees that were Ficus virens var. sublanveolata, Ficus benjamina, Roystonea regia, Terminalia hainanensis, T.

结果表明：1梅州城区行道树共有13科18属23种7133株，其平均胸径、平均冠幅、平均树高分别为27.59cm，4.10m，6.94m，总体上看，平均冠幅偏小；2物种丰富度指数S、Shannon-Wiener指数H和Simpson指数D偏小且各道路间差异明显，说明各道路行道树存在一定程度的物种单一性、层次的单调性；3梅州市城区行道树优势树种是大叶榕、垂榕、大王椰子，次优势种为海南榄仁、阿珍榄仁、阴香，它们是梅州城市街道绿化的好树种。

With the support of a major research grant of Zhejiang Province (No. 001101027) and the Plan of Promoting Education of Excellence of Zhejiang University in the 21st Century, this dissertation is devoted to address the above problems and fabricate an L-band EDFA with low cost, high performance and technological innovation.First the mechanism of an erbium doped fiber amplifier is introduced. Various theoretical models based on classical rate propagation equations are summarized and compared for their applications. We use a modified numerical model based on the Giles model, which agrees with the experimental results well. This serves as the theoretical base for the whole thesis and will be used to optimize the characteristics of EDFAs. A novel method based on a map of noise figure and gain is proposed to analyze efficiently the dependence of the noise figure and gain for EDFAs on the EDF length and the pump power. The characteristics of various EDFAs are studied and compared.Secondly, some important parameters are introduced to describe the characteristics of EDFAs. The methods and the experimental setups for measuring the gain and noise figure of an EDFA are emphasized. We introduce how to measure the characteristics of each component of an EDFA, especially the gain and absorption coefficient of an erbium doped fiber.Thirdly, four types of simple and novel L-band EDFA structures with low noise, high gain and low gain ripple are proposed to satisfy the requirement of a DWDM system. They can be classified into two categories. In the first category, a single ASE pumping is served asa secondary pump. This category includes the following three types. Type: a new construction using a fiber Bragg grating in an unpumped EDF section at the input side. Type: a new structure of L-Band EDFA with two-stage pumps, which utilizes the forward ASE as a second pump.

本论文本着科技创新、服务于生产实践的精神，以设计价格低廉，性能优越、结构合理简单的L-band EDFA为目标，依托浙江省科技厅重大科学基金资助项目(001101027)和浙江大学振兴教育计划资助的全光网络的搭建—《光通信技术》课程实验建设项目，展开了如下工作：首先，介绍了掺铒光纤放大器的工作原理，归纳总结了基于速率方程基础的EDFA的各种理论模型，分析比较了各个模型的特点和适用场合，最终选择完善的Giles理论模型作为本论文分析设计EDFA的理论基础；针对实际实验条件提出了修正的EDFA模型的数值计算方法；创新地提出了增益—噪声系数全局分析法，直观有效地分析了EDFA的增益和噪声系数与掺铒光纤长度和泵浦功率的依赖关系，并对各种EDFA的性能作了全面的比较；第二，介绍了掺铒光纤放大器特性参数的定义与测量方法，重点介绍了噪声系数和增益系数的测量方法及实验装置；介绍了组成掺铒光纤放大器各组件的特性测量方法，重点介绍了测量掺铒光纤参数的方法和实验装置；第三，针对WDM系统对L-band EDFA谱平坦、低噪声、高增益的要求，我们创新地提出了四种不同的L-band EDFA结构，按设计思路可以分为两大类：一类是基于单抽运二级泵浦法，这一类包括在未泵浦掺铒光纤的输入端插入一根布拉格光纤光栅的两段L-band的EDFA的新结构；基于前向ASE光作为二级泵浦源推动下一级EDF工作的泵浦分配、两段级联L-band的EDFA的新结构；基于单根光纤光栅、泵浦分配、两段级联的EDFA；另一类则是基于同时应用前后向C-band ASE作二级泵浦源的双抽运法，如基于前后向ASE光作为二级泵浦源的三段级联L-band的EDFA的新结构。

Objective To determine the oviposition responses of Anopheles sinensis to bacteria A4, Aeromonas sp. and Enterobacter sp. and whether or not the three strains attracted the mosquitoes, providing theoretical and experimental evidence for the application of the three bacteria in the intervention of malaria. Methods Blood?fed and held for 48-60 h, copulated female An.

目的 具吸引作用的细菌或其挥发物能提高按蚊与杀虫或抗疟工程细菌接触的机会，为此，拟测定中华按蚊对A4细菌、气单胞菌和肠杆菌的产卵反应特性，以明确3种细菌对中华按蚊是否具有吸引特性，为应用这3种细菌开展阻断疟疾传播研究提供理论和实验依据。

What she stumbled upon was not only a new life but a new way to make a living.

她所决策的并单是一种新的生活，而且是一种新的谋生方式。

But it's probably a migraine if your headache has at least two of these four traits: It's one-sided, it throbs, the pain is moderate to severe, and it gets worse with physical activity.

但如果你的头痛至少包含了下列四种特点中的两种的话，它就可能是偏头痛：单侧、悸动、疼痛适中以及随着身体的运动而加剧。

Smilax, there are the phylogenetic relationships and distributive pattern to be found based on the combined ITS and maiK. tree: 1 a clade with the African species (S. kraussiana) and Australian species (S. australis), being a sister group; 2 a clade with the S. zeylanica of sect. Macranthae and S. bona-nox of sect. China, the former from Southeast Asia and latter native to US, showing they are a sister species which is disjunctive between Asia-North America, similar to the species pair of S. hispida and S. sieboldii; 3 S. perfoliata from Indonesia being sister to S. ocreata of China and S. megacarpa of Indonesia, which are very similar to each other in morphology; 4 the three species from China (S. lanceifolia, S. perfoliata and S. chapaensis) and S.ovalifolia from Indonesia showing a 87-92% bts monophyletic clade; 5 S.bracteata from China and two species of Indonesia (S. leucophylla and S. sp.) forming a clade in the ITS tree; 6 S.

通过比较研究圆锥花序组和穗菝葜组的地理分布，基于ITS及matK联合数据构建的系统树发现下列明显的具系统发育关系的类群及地理分布模式：1来自非洲的S.kraussiana和来自澳大利亚的S.australis是一对姐妹群，具有共同的祖先；2圆锥花序组的S.zeylanica和菝葜组的S.bona-nox形成一个紧密的分支，前者分布于东亚而后者只局限于美国，显示了一种类似于S.sieboldii和S.hispida那样的东亚—北美间断分布模式；3印度尼西亚的S.perfoliata是分布于中国的S.ocreata和来自印尼S.megacarpa的姐妹群，这三者在形态上也非常接近，表明具有共同祖先；4来自中国的三个种(S.lanceifolia，S.perfoliata and S.chapanensis)和来自印尼的S.ovalifolia形成了一个高支持率的单系分支(87-92％bts)；5基于ITS的系统树，来自中国的S.bracteata和来自印度尼西亚的两个种S.leucophylla and S.sp。

As a singlet curved lens is impossible to correct all the five primary aberrations regardless it is made of PIMs or NIMs, the primaxy-aberration-free lens systems composed of two thin lenses or two thick lenses based on the use of NIMs are intentionally presented.

由于只靠单块曲面透镜是无法同时消除全部五种初级像差的，因而我们接着研究了由负折射率介质构造的能同时消除全部五种初级单色像差的双薄透镜组合系统和双厚透镜组合系统。

According to the clear water experiment, aeration performance of the new equipment is good with high total oxygen transfer coefficient and oxygen utilization ratio.

曝气设备的动力效率在叶轮转速为120rpm～150rpm时取得最大值，此时氧利用率和充氧能力也具有较高值。

The environmental stability of that world - including its crushing pressures and icy darkness - means that some of its most famous inhabitants have survived for eons as evolutionary throwbacks, their bodies undergoing little change.

稳定的海底环境─包括能把人压扁的压力和冰冷的黑暗─意谓海底某些最知名的栖居生物已以演化返祖的样态活了万世，形体几无变化。