小的环

At the same time, the center conditions and bifurcation of limit cycles at the origin of the quintic polynomial system are also investigated.

第二章研究了一类三次多项式系统由细焦点分支出极限环的问题，证明了该系统有12个小振幅极限环，证明过程是符号和代数的，且焦点量的表达式相对简单。

And the physical gelation, which corresponds to the crosspoint of modulus G'and G, was resulted from the vitrification of thermoplastic-rich phase.

对照两相组成与转化率的相图发现，环氧体系的转化率在相分离过程中变化很小，而且一般早于环氧的化学凝胶点。

The UV and IR spectroscopic studies of the monomer films showed that the photoreaction ratio of monomer (about 50%) was higher than the corresponding photosensitive polymer (about 10%, PVCi). The polarized IR spectra proved that obvious anisotropic absorption was displayed in the irradiated photosensitive film. With polarizing microscopy method, we found that these kinds of photoalignment films exhibited good alignment ability, and the stability of the photoalignment film could reach about 100℃. 2 A photosensitive self-assembled monolayer was fabricated that contained photo-cycloadditable groups, such as, coumarin and cinnamate. The reaction process were detected by contact angle method because the IR absorption of monolayer was very weak. The photosensitive self-assembled monolayer promote uniform alignment of nematic liquid crystals by LPUV, and it thermal stability could reach about 130℃. 3 A cationic bolaform amphiphiles was synthesized that had two photosensitive double bonds, and can be polymerized by ultraviolet. A layer-by-layer self-assembled deposition film was prepared in aqueous solution by using this material and poly (sodium 4-styrenesulfonate). The UV-Vis. spectra proved that the multilayers film was uniform and layer-by-layer. When LPUV irradiated the film, the photopolymerizable double bond underwent [2+2] cycloaddition, and the production of the reaction distributed along the polarized direction of incident LPUV. Polarized UV-Vis. spectra indicated that the irradiated self-assembled multiplayer film was anisotropic, and the dichromic ration is about 0.09, it is higher than the spin-coating method of photosensitive polymer or monomer. We used this anisotropic film as alignment layer of nematic liquid crystals, and obtained a uniform and stability alignment result, the static contrast ratio is about 100, which is very close to application of liquid crystal device. This thesis is an instance that the photochemical material was used in the physics region of liquid crystals, the route that was from photosensitive monomer, self-assembled monolayer film to self-assembled multiplayer film was undergone, by this logical research method photoailgnment of liquid crystal was extended and consummated.

围绕上述思路开展了如下工作：1合成了三种可进行光二聚反应的光敏小分子单体，LPUV 辐照制作了光控取向膜；用紫外-可见光谱法和红外光谱法分析了薄膜中的光化学反应，发现小分子的光反应程度可达到50%以上，至少比光敏高分子高出5倍；薄膜的偏振红外光谱证实，经过LPUV 辐照后薄膜出现了明显的各向异性；将小分子光控取向膜制成液晶器件，在偏光显微镜下观察看到均匀一致的液晶取向；并且热稳定性达到100℃左右，接近实用化要求。2制备了含肉桂酸、香豆素基团的自组装单层膜；采用接触角的方法监测自组装反应的动力学过程；紫外-可见光谱证实了自组装单层膜在石英基板表面形成；自组装单层膜经LPUV 辐照后能诱导液晶均匀取向，而且热稳定性可达130℃，热稳定性进一步提高。3合成了含有光敏双键的双季铵盐，在水溶液状态下将它和聚乙烯基苯磺酸钠沉积生成layer-by-layer 自组装多层膜，紫外-可见光谱证实这是一个逐层均匀的沉积；在LPUV 照射下，自组装膜中的光敏双键按照偏振方向发生[2+2]环加成反应，形成取向膜，用二向色性值评价的分子取向度高于高分子及小分子光控取向膜的水平；实验证明用自组装多层膜制成的液晶器件亮暗态均匀，静态对比度约为100，达到实用化器件的水平。

Chapter 6: Iodobenzene diacetate-mediated reactions of methylenecyclopropanes, vinylidenecyclopropanes and a methylenecyclobutane with phthalhydrazine give the corresponding [3+2] cycloaddition products in good yields under mild conditions. In these reactions, phthalhydrazine was transformed to a 1,3-dipole intermediate in the presence of iodobenzene diacetate. A plausible reaction mechanism has been proposed.

本论文对亚甲基环丙烷类化合物的一些化学反应性能进行了研究，发现了亚甲基环丙烷类化合物在不同试剂或不同催化剂作用下的一些新的化学转化并合成了一些结构简单但具有潜在应用价值的有机小分子。

PartⅡ:Effect of bicyclol on hepatocyte apoptosis in alcohol-intoxicated mice and related mechanismsThree consecutive intragastric administration of alcohol(6g/kg)in 12h interval resulted in an obvious liver injury and inflammation in mice,as indicated by the elevation of serum alanine transaminase(2.2 fold of control),increased hepatic COX-2 protein expression(2.2 fold of control),as well as liver pathological changes characterized by myelonic degeneration,vacuolar degeneration and inflammatory infiltration.

双环醇对酒精中毒小鼠肝脏细胞凋亡的保护作用及机制研究小鼠连续三次酒精(6g/kg)灌胃后可导致明显肝损伤，变现为血清ALT水平升高(为对照组的2.2倍)，肝脏炎症相关蛋白环氧合酶-2(cyclooxygenase-2，COX-2)表达增加(为对照组的2.2倍)，肝组织出现髓样变性、小空泡变性和炎性细胞浸润。

Every harbour is small but combination in administrative divisions inner formation since the rim of Bohai Bay does not realize the long similar triangle , limpid-rization , leading to ring the Bohai Sea harbour resource duplication of similar projects and contending for source of goods , the nothing order racing to control hinderland competing neither samer than long triangle harbour group "an integral whole both wings " develops power state's is especially more fierce than growing a triangle.

但是由于环渤海地区还没有实现类似长三角各港口在行政区划内形成的小组合，也不同于长三角港口群&一体两翼&发展势态的清晰化，导致环渤海港口资源重复建设和争夺货源、抢占腹地的无序竞争比长三角更加激烈。

The new images hint at an inner ring about half the diameter of the main ring, and so the actual clear "eye" region is smaller than it appeared in earlier low-resolution images.

新图像显示，有一个内环大约是主环直径的一半，因此实际上纯粹的风眼区比以前低分辨率图像中所显示的更小。

The X-ray analysis of the chiral macrocycle Ⅲb shows that the chiral ligand with acavity is rather rigid and strained. The unsymmetrical spatial structure of Ⅲb wellexplains the different recognition to chiral small molecules.

结果表明大环Ⅲb是具有一定大小空腔的扭曲型刚性分子，这种环系的不对称空间结构能够很好地解释它对手性小分子的不同识别作用。

The Cassini spacecraft has revealed a never-before-seen level of detail in Saturn's F ring, including evidence for the perturbing effect of small moonlets orbiting in or close to the ring's bright core.

卡西尼飞船显示出土星F环前所未见的细节，以及靠近或在环的明亮核心地带的小卫星造成的扰动证据。

Because of the fact, the bearing capacity of the whole drive cannot be developed well enough. To improve the performances of the load-capacity, transmission efficiency, and reliability of mechanical drive, we originally developed some designs of the double crank ring-plate-type cycloid planetary drive. The new-type drive keeps all the natural advantages, which is of multi-tooth mesh, small mesh angle, and hardened tooth flank of gears. Moreover, The drive does not need the special output unit as the ring-plate-type drive does, so that the rigidity of the output shaft becomes much higher. Since the tumbler bearing is placed outside the cycloidal gear, the size of the bearing is no longer restricted to any extent.

为大幅度提高其承载能力、传动效率和可靠性诸指标，我们创新研究出来的多种结构双曲柄环板式针摆行星传动，其特点是不仅保留着原摆线针轮行星减速器同时啮合齿数多，总法向力与总圆周力间夹角小，摆线轮与针轮齿均为硬齿面等本质上的优点；而且又具有环板式传动省去输出机构且输出轴刚性好，转臂轴承移至行星轮外，从而传递的转矩可以成倍提高的优点。

Neither the killing of Mr Zarqawi nor any breakthrough on the political front will stop the insurgency and the fratricidal murders in their tracks.

在对危险的南部地区访问时，他斥责什叶派民兵领导人对中央集权的挑衅行为。

In fact,I've got him on the satellite mobile right now.

实际上 我们已接通卫星可视电话了