四对的

There is linear relationship between the chemical shifts of B ring protons and the substituent parameters.

四、对14个合成的B环对位取代异黄酮化合物核磁共振氢谱进行了研究。

In this text we used the method of volume integral equation base on tensor Green's function to study the forward of 4D transient electromagnetic response.

本文采用基于张量格林函数的体积分方程法进行四维模型瞬变电磁响应的正演研究，文章中首先说明了四维瞬变电磁法模拟的可行性及程序实现，然后分别设计了两个三维异常体模型，采用两种观测方式(激发与接收平行、激发与接收垂直)进行正演模拟计算，并对所得的二次总场的数据进行了分析。

Using poly (4-merhylpentene-l) as a membrane material and cyclohexane, irich-loroethylene, tetrachloroethylene, mixture of cyclohexane and trichloroethylene or tetrachloro-ethylene as solvents, the solution were cast to form homogeneous dense membranes, and the crystalline properties and surface morphology were investigated by DSC and TEM.

以聚4-甲基戊烯-1为膜材质，分别以环己烷、三氯乙烯、四氯乙烯、环己烷/三氯乙烯及环己烷/四氯乙烯为溶剂，研究了这些溶液浇铸膜的结晶性质和表面形态。结果表明，溶剂对PMP的相对溶解能力和挥发速度同所成膜内PMP的结晶形式和结晶度密切相关；不同溶剂体系的PMP溶液浇铸膜的表面形态也不尽相同。

Some models were designed where the unique tetragon and hexagon grids borrowed from the wing structure were used as the basic elements, these models were analyzed numerically, it is shown that the model consisting of tetragon grids is much stiffer than that consisting of hexagon grids, while, more material is used in the first model;crinkling models based on tetragon grids or arched models consisting of hexagon grids become more stiffer than flat ones;hybrid models consisting of tetragon grids and hexagon grids can realize a proper balance between material saving and stiffness improving.

分别提取四边形、六边形的基本网格，建立结构模型，并对它们进行非线性数值分析。研究发现：四边形网格结构刚度大，六边形网格结构刚度小；而从材料利用率角度来讲，六边形网状结构更省材料；起皱对四边形网格结构刚度有加强，而起拱对六边形网格结构刚度有提高；如果将四、六边形的网格进行合理搭配，可以使结构刚度和材料利用率得到优化。

The contents of crude protein and 18 kinds of amino acids in the powder of tetraploidy black locust for fodder leaves at four stages,from which Langfang,Hebei Province,were determined.Their value for feeding were evaluated by means of amino acid scores and essential amino acid index.

测定了廊坊地区饲料型四倍体刺槐叶粉4个不同时期的粗蛋白质含量及18种氨基酸组分，用氨基酸分和必需氨基酸指数对其氨基酸营养进行评价，并结合其生物量对最佳刈割时期进行了分析。

You'll find him two-faced because he speaks one thing to one person and the opposite to another.

你会发现他是虚伪的，因为他对张三这么说，对李四又那么说。

Aim: To determine whether activation of κ-opioid receptor with U50,4 88 H, a selective κ-opioid receptor agonist, produces any changes in electrical u ncoupling during prolonged ischemia and whether these changes in electrical unco upling is associated with the cardioprotection induced by κ-opioid receptor ac tivation, and to explore the possible mechanism.

测量指标：以分光光度计在490nm波长下测定氯化三苯基四氯唑与活细胞反应的产物formazan含量的方法测定心肌细胞活性、测定冠脉流出液中乳酸脱氢酶的含量以及心室内压；②全心停灌70min，应用四电极法观察不同浓度U50，488H、nor-BNI和5-HD对缺血期间心肌整体阻抗和电脱耦联参数(电脱耦联时间、平台时间、电脱耦联最大速率和阻抗倍数)的影响。

This paper first elaborated the principle of SINS, some interrelated information,and the affect of renewed arithmetic to the system"s precision. Then, we studied thequaternion in traditional renewed attitude arithmetic. The quaternion is simple, andwhen run it into computer, it"s time saving. So, this arithmetic is often adopted byengineering. However, the quaternion brought unexchangeable error inevitably. Whenthe carrying body moves in highly dynamic situation, the error would become larger.So we should take effective measure to get over it.

本文首先论述了捷联式惯性导航系统的工作原理及相关知识，捷联惯导系统姿态更新算法对系统精度的影响；其次研究了传统的姿态更新算法中四元数法，该算法简单，计算量小，因而在工程中经常被采用，但是在四元数法中不可避免的引入了不可交换性误差，特别是在载体处于高动态环境时，这种误差就会很大，必须采取有效措施加以克服。

The observation showed that sterile plants and fertile plants in the pollen mother cell stage is not very different, when microspore mother cells of male sterile plants enter meiosis period, it could form normal tetrad cell , tetrad cell is normal in early development stage, In the uninucleate microspore stage , tapetal cells were vacuolization, the microspores were extruded to the middle by tapetal cells.

本研究利用石蜡切片法，结合光学显微镜技术对樱桃萝卜核质互作雄性不育系的不育株和对应保持系可育株的花药发育过程进行细胞形态学观察，观察结果表明：不育株与可育株在花粉母细胞时期差别不大，不育株的花药小孢子母细胞进入减数分裂期后，可以正常的形成四分体，四分体前期发育正常，而在单核小孢子期绒毡层细胞出现液泡化，绒毡层细胞向中间挤压小孢子。

Results Vector algebra and vector analysis are the production of quaternions and the result of seeking mathematical indication of physical phenomenon, it′s the historic certainty as well as the effect of some accidental elements.

结果现代向量系统是从四元数发展而来的，是寻找物理现象的数学表示的结果；通过对哈密顿四元数与格拉斯曼系统的对比分析指出其历史的必然性。

This one mode pays close attention to network credence foundation of the businessman very much.

这一模式非常关注商人的网络信用基础。

Cell morphology of bacterial ghost of Pasteurella multocida was observed by scanning electron microscopy and inactivation ratio was estimated by CFU analysi.

扫描电镜观察多杀性巴氏杆菌细菌幽灵和菌落形成单位评价遗传灭活率。