运用适度原则预防车用CNG气瓶事故

将本质安全原理的适度原则与车用压缩天然气（CNG）气瓶事故的风险控制相联系,介绍了本质安全原理及其基本原则,阐述了车用CNG气瓶的事故形式,分析了车用CNG钢制气瓶、缠绕气瓶和全复合材料气瓶的安全可靠性。基于本质安全原理的适度原则讨论了预防车用CNG气瓶事故的措施与方法,并阐述了本质安全原理与车用CNG气瓶事故预防措施之间的关系,对已制定的事故分析控制措施进行完善和补充。     

液压吊车起重臂系统设计方法研究

本文通过对液压吊车起重臂四构件机构运动学分析，推导出起重臂系统总体布置方案设计和计算油缸最大工作载荷的新方法，为合理选择油缸尺寸和类型提供了可靠的依据。经设计实例验证，新设计方法可以迅速、方便的确定设计方案，比作图试凑法和以油缸安装尺寸为依据的设计方法更能合理地满足实际工作要求，具有较高的精度。     

超高压多层热套组合厚壁简优化设计探讨

本文根据多层热套组合厚壁筒加工制造时由里向外逐层热套的工艺过程，分析了任意一层内壁的环向应力、径向应力和最大剪应力，利用Ｈ．Ｔｒｅｓｃａ屈服条件及Ｌａｇｒａｎｇｅ乘数法，对这类厚壁容器的优化设计方法进行了探讨，导出了一系列实用的计算公式，供设计及制造部门参考。     

Liquid crystalline networks composed of pentagonal, square, and triangular cylinders

T-shaped molecules are designed in such a way that they self-organize into nanoscale liquid crystalline honeycombs based on polygons with any chosen number of sides. One of the phases reported here is a periodic organization of identical pentagonal cylinders; the other one is a structure composed of square-shaped and triangular cylinders in the ratio 2:1. These two different packing motifs represent duals of the same topological class. The generalization of the concept applied here allows the prediction of a whole range of unusual complex liquid crystalline phases.     

介电式带绒棉种分选机滚筒数量的研究

为了确定介电式带绒棉种分选机应配备的滚筒数量，在单滚筒介电分选机上对带绒棉种进行了不同分选电压下不同分选次数的试验，并利用t检验法对试验数据进行了显著性检验。结果表明：介电式带绒棉种分选机配置2个滚筒是必要的，可以显著提高分选效果；如果配置3个滚筒进行3次分选，不仅不能提高分选效果，反而会使棉种损失量增加。     

空气罐控制管道水击实验研究

在实验室的简单管路水力系统中，加设一种气囊式空气罐，进行简单管路的水击实验，可以有效地控制水击危害，并模拟出生产管道的水击动态特性，这种空气罐具有气密性、可梗换节流孔口、计算机能够模拟罐的容积的结构特点，用以达到控制管路系统中因阀门瞬时关闭产生的水击增压速率，并防止液柱分离，在瞬变分析忽略阀门和罐间摩阻、三通连接的局部摩阻、罐和管路间的摩阻、液流惯性和罐内液面变化的前提下，建立了阀门、窑罐的复合边     

穴盘苗自动移栽机械手的结构设计与仿真

通过穴盘苗钵体受力及夹持的工作原理分析,确定出机械手末端执行器结构参数。用3个汽缸分别来完成竖直方向、水平方向及手指开合的运动,通过合成运动实现了手指端插及穴盘苗钵体的动作。应用ADAMS对机械手进行了运动学仿真及合成运动的轨迹分析,确定了最优的工作速度,验证了机械手设计的合理性,完成了穴盘苗移栽机械手样机的试制。     

回转高副机构的动态优化设计原理研究

本文从两圆柱构件直接接触形成迴转高副机构的实际情况出发,分析其失效的基本原因,提出了系统参数的优化问题,建立了在动态情况下的设计原理。     

轴线相交的直线回转体相贯线的解析分析

对轴线相交的柱—柱、柱—锥、锥—锥相贯线的性状进行了解析分析,得出在轴线正交情况下相贯线特殊点的图解方法,轴线斜交情况下相贯线的特殊点也可根据本文中的分析方法应用仿射原理得出。     

New Technique for the Collection and Isolation of Airborne Microorganisms

Pure cultures of airborne microorganisms are obtained by simple electrostatic attraction to small glass and plastic cylinders which are rolled over the surface of nutrient agar medium. Little equipment is required, and the necessary materials are inexpensive. Satisfactory qualitative sampling is possible under varying conditions of relative humidity.     

Structure of water in microemulsions: electrical, birefringence, and nuclear magnetic resonance studies

Microemulsions, which are optically transparent oil-water dispersions, were produced by mixing hexadecane, hexanol, potassium oleate, and water. As the amount of water is increased, the microemulsion exhibits a clear to turbid to clear transition. In contrast to the clear regions, the turbid region possesses birefringence. The development of birefringence is also accompanied by a sharp decrease in the electrical resistance. The high-resolution (220 megacycle) nuclear magnetic resonance data suggest that water exists in two distinct molecular environments in the birefringent region; the first environment is characterized by relatively less mobile water molecules than oil molecules, whereas in the second environment oil molecules are less mobile than water molecules. The electrical, birefringence, and nuclear magnetic resonance data are in agreement with the proposed mechanism of change in the structure of water from water spheres to water cylinders to water lamellae. The chemical shift of water protons suggests that the molecular environment of water in spheres is different from that of water in cylinders or that of water in lamellae.     

巢式PCR检测油茶根腐病菌的研究

为建立油茶Camellia oleifera根腐病菌层生镰刀菌Fusarium proliferatum的巢式聚合酶链式反应（PCR）快速检测体系．扩增层生镰刀菌核糖体DNA基因间隔序列（ITS）区并测定其序列,比较该序列与GenBank中近似种的ITS序列差异．设计了特异性引物GF1和GR2,利用该对引物与ITS1和ITS4进行巢式PCR扩增检测层生镰刀菌。结果显示,巢式PCR对层生镰刀菌的检测灵敏度可达100ag基因组DNA,比常规扩增方法提高了1万倍。利用设计的GF1／GR2特异性引物与ITS区通用引物进行巢式PCR扩增．可灵敏地扩增出油茶根腐病菌层生镰刀菌DNA。     

两种脱粒滚筒的玉米籽粒损伤试验研究

脱粒是玉米种子加工的关键环节，也是影响种子质量的一个重要因素。尽量减少脱粒过程中的机械损伤是研制玉米种子脱粒机的关键指标。通过两种脱粒滚筒的脱粒对比试验表明：改变脱粒部件的机械作用力能有效地降低籽粒损伤，为改进脱粒方法及新型玉米种子脱粒机的研制提供参考。     

用双圆柱代替V形块作定位元件的定位误差分析

本文分析了用双圆柱代替 V 形块作定位元件时所产生的定位误差,推导了三个定位误差计算公式,并与 V 形块定位作了某些对比分析。     

声子晶体中声子频率带隙与散射截面的关系

用平面波方法,研究了Pb圆柱体在环氧树脂基体中按周期性排列构成的声子晶体中弹性波频率带结构,同时计算了弹性波在这种二维周期性复合介质中的散射截面,阐述了声子频率带隙与散射截面的关系.     

Flea Ctenophthalmus: heterogeneous hexagonally organized layer in the midgut

The ventriculus or midgut of adult fleas of the genus Ctenophthalmus (Hystricopsyllidae) is surrounded by a complex investment consisting of a "beaded layer," circumferential and longitudinal muscles, minute fibrils of the sort commonly called collagenous, and a granular layer at the boundary of the hemocoel. The beaded layer is remarkable in consisting of two types of short cylinders of greatly different diameters, each type arranged in a mixed hexagonal array.     

Endoplasmic reticulum in rat renal interstitial cells: molecular rearrangement after water deprivation

Cylindrical bodies in renal interstitial cells of dehydrated rats are confluent with membranes of endoplasmic reticulum. The cylinder walls, composed of helically arranged pentagonal tubules, may represent a molecular rearrangement of the membrane structure. The cylinders may represent a morphologic expression of altered ergastoplasmic function possibly related to the production of concentrated urine.     

地下工程导线测量中加测陀螺方位角的最佳位置研究

针对地下工程导线测量中,采用测角量边的单一导线控制测量而导致控制精度较低的问题,分析了直伸型导线测量中加测陀螺方位角的数量及其增益,并探讨了直伸型导线和非直伸型典型导线,如L,Z,U型导线加测陀螺方位角的最佳位置。     

Spin-liquid ground state of the S = 1/2 kagome Heisenberg antiferromagnet

We use the density matrix renormalization group to perform accurate calculations of the ground state of the nearest-neighbor quantum spin S = 1/2 Heisenberg antiferromagnet on the kagome lattice. We study this model on numerous long cylinders with circumferences up to 12 lattice spacings. Through a combination of very-low-energy and small finite-size effects, our results provide strong evidence that, for the infinite two-dimensional system, the ground state of this model is a fully gapped spin liquid.     

水蛛气管的形态学观察与比较

水蛛(Argyroneta aquatica)是目前世界上唯一栖息在小溪、池塘、沼泽等小型水体中以捕食小鱼、小虾、昆虫幼虫为生的蜘蛛,广泛分布于古北界。本文对水蛛气管结构进行了形态学观察研究,并与3种常见陆生蜘蛛——宁波熊蛛(Arctosa ningboensis)、广缕网蛛(Psechrus senoculatus)和大腹园蛛(Araneus ventricosus)的气管结构进行了比较。发现水蛛气管为两条并排的圆柱体,其圆柱体两端伸出许多微气管分支,分别向前向后延伸入水蛛头胸部以及水蛛腹部中后端。其他3种蜘蛛的气管结构均为简单的4管型。复杂的气管结构体现了水蛛对气管更为高效的利用率,同时也发现水蛛的气管结构最为发达,说明其新陈代谢水平与运动水平也超过了常见的陆生蜘蛛种类。本文不仅对水蛛气管进行了观察比较,还讨论了水蛛气管结构与功能之间的关系,发现高度复杂的气管结构是水蛛对其独特的水下生存环境的一种适应,证明了气管在蜘蛛进化中的重要地位,为国内蜘蛛气管研究提供基础资料。