Phenyl group introducing to cholesteryl ester molecules can enhance the phase transition temperatures of the liquid crystals and their stability . an increase in the chain length for cholesteryl dicarboxylate samples reduced stability of liquid crystal phases . while coattail - like structures on the ester group of the molecules have an adverse effect to form cholesteryl liquid crystal phase 化学结构对液晶性的影响表现为：分子中引入苯环刚性结构可以提高液晶的相变温度和稳定性；脂族二羧酸胆甾醇酯中脂肪链的长度增加会降低液晶的稳定性；而末端含有燕尾结构则对液晶态的形成产生不利影响。
The essay researched the compressive strength , bending strength , impact resistance and abrasion resistance of high strength polypropylene fibermesh concrete the mechanism of enhancing the properties of high strengh poloypropylence fibemesh road concrete composite was discussed and analyzed the regression on tensile strengh with portland cement mixed with fiber was derived using experiment the tensile strength of fiber soil stablization with porland cement was increased with dosage and length of fiber while the former was more effective than the latter test and analysis results indicate that polypropylene fiber can not only reinforce the strength of concrete , but also obviously promote the flexural fatigue life by the great stress the application of polypropylence fiber reinforced concrete in pavement construcion are also introduced 文章研究了不同掺量有机纤维混凝土的抗压、抗折强度、抗冲及性能、疲劳性能及耐磨性等各种路用性能，综合论述了有机纤维对水泥混凝土路用性能的影响。通过试验阐述了纤维水泥混凝土各种路用性能与纤维掺量、长度间的关系。分析表明纤维水泥混凝土随着纤维掺量和长度增加而增加，且纤维掺量对纤维混凝土抗拉强度的影响比纤维长度的影响更大。
Plants growing in the semi - fixed sand dunes , on the other hand , were less branchy with a larger number of first - year shoots which were longer , and grew faster ; their leaves were longer and wider with a low length / width ratio . the characteristics of the branching system and leaf dimensions of the plants in fixed sand dunes were rather intermediary between those of the above . the frequency distribution and their frequency in the herb layer the scrubs also varied with habitats 丘间低地的黄柳灌丛当年枝平均长度增加缓慢，短枝条的比例较高，当年枝枝长频度分布峰值偏左，叶片短而狭，长宽比大；与之相比，分布于半固定沙丘的灌丛当年枝平均长度增加较快，长枝条比例较高，叶片长而宽，长宽比小；固定沙丘上的上述特征大致介于二者之间。
But when the dredged length have increased to a certain value , the increment of water level drop datum decreased continuously with length increase of dredging channel . in other word , unit length increment tends to slowly . when dredging channel length is in a certain datum region , the effect of dredging sediment for deposition reduction is better relatively 但是，当长度增加到一定值以后，随挖河长度的增加，水位跌落值增量不断减小，即单位长度的增加量逐渐趋缓；当挖河长度取于某一值域内时，挖河的减淤效果才相对较佳。
It has been put forward that quality index of geotgrids should be the tensile strength , strain , and strain rate , and the sizes of geogrid " s sample for strain test are suggested ; the tensile strength of geogrid increases with increase of width of test sample , while the strain rate decreases as the pullout rate , length of sample increases , and when the pullout speed is larger , the strain rate varies with the width and length of sample , otherwise , the strain rate has little to do with them . . 2 提出了将抗拉强度、延伸率和延伸速率作为土工格栅的质量控制指标，并将士工格栅延伸速率纳入某些工程设计参数；建议土工格栅的延伸率测试试样宽度至少3根，长度至少3节；并发现土工格栅抗拉强度随宽度增加而递增，土工格栅延伸率随拉伸速率、试样长度增加而减小，当拉伸速率较大时，延伸速率与试样长度、宽度均有关；反之则基本无关。
Firstly , in this dissertation , two types of symbol start time estimation schemes for orthogonal frequency division multiplexing ( ofdm ) systems are evaluated and analyzed . simulation results suggest that : pilot symbol based synchronization has better performance over cyclic prefix based schemes , and it performances improved when the length of pilot symbol increases ; cyclic prefix based synchronization method has a high spectrum efficiency in spite of its relative low acquisition of synchronization rate ; and the former is more suitable to bursting symbol based information systems , such as ieee802 . 11a , while the later can be used in broadcasting systems for continuous media streams , such as digital video broadcasting systems , digital audio broadcasting systems 首先,论文从同步获取的角度对ofdm系统中的两类时域符号同步方案进行了性能分析,并通过大量的仿真说明:基于训练序列的同步方法具有较好的同步获取成功率,其性能随训练序列的长度增加而改善;基于循环前缀的同步方法,其同步获取成功率较低,但是具有较高的频谱利用率;前者适用于突发数据帧传输系统,如ieee802 . 11a等,后者适合广播式连续媒体流传输系统,如数字音频、数字视频系统。
