小直径石油测井中子发生器研制

为满足国内油田石油测井的迫切需要, 对小直径测井中子发生器进行了研发。 该发生器离子源采用微型化冷阴极Penning离子源, 离子光学采用结构简单的单极加速系统。 经实验室测试和用户现场刻度及测井表明, 研制的中子发生器具有耐高温、 产额高、 稳定性好等特点, 是目前国内研制的最小直径的工业测井中子发生器。 所测数据与其它测井方法相比较, 地质资料符合性好, 满足了用户测井要求, 现已用于油田生产测井。 A small neutron generator has been developed for meeting the need of well logging in oil fields. The miniature cold cathode Penning ion source and single electrode ion optics system are used in neutron generator. The good performance of the generator has been proved in the laboratory test and well logging in oil field. The generator has good characteristics, such as small diameter, high temperature resistant,high neutron output and good stability. At present, the neutron generator is the smallest logging generator in China, which has been used in oil field generally for conforming the geological data.     

Effects of Colored Noise on Periodic Orbits in a One-Dimensional Map

Noise can induce inverse period-doubling transition and chaos. The effects of the colored noise on periodic orbits, of the different periodic sequences in the logistic map, are investigated. It is found that the dynamical behaviors of the orbits, induced by an exponentially correlated colored noise, are different in the mergence of transition, and the effects of the noise intensity ontheir dynamical behaviors are different from the effects of the correlation time of noise. Remarkably, the noise can induce new periodic orbits, namely, two new orbits emerge in the period-four sequence at the bifurcation parameter value μ=3.5, four new orbits in the period-eight sequence at μ=3.55, and three new orbits in the period-six sequence at μ= 3.846, respectively.Moreover, the dynamical behaviors of the new orbits clearly show theresonance like response to the colored noise.     

聚DL-乳酸的合成及其热性能研究

以辛酸亚锡为催化剂催化丙交酯开环聚合DL-乳酸(PDLLA)。研究了影响PDLLA分子量的因素包括丙交酯单体的纯度、催化剂的浓度、反应温度、反应时间及真空度等。用DSC,TGA分析了不同分子量PDLLA的警警化转变和热失重。结果表明,PDLLA是热不稳定聚合物,残留的单体、催化剂及低聚物是影响PDLLA热稳定性的因素,除去其中残留的单体、催化剂及低聚物可以提高PDLLA的热稳定性。     

Population Growth of Small Harmful Rats in Grassland Subjected to Noise

The population growth of small harmful rats in grassland subjected to environment fluctuation has been modelled in a logistic equation. Two correlated random variables responsible to the fluctuation of the genetic factor and the suppression factor are used. A two-peak structure of the steady probability distribution of rate population is observed in the large fluctuation regime of the genetic factor. With the increase of correlation constant A, the steady probability distribution can change from two peaks to a single peak. The suppression factor μ and its fluctuation also affect the steady probability distribution and can push it toward a small population.     

A new analytical solution to axisymmetric Blot's consolidation of a finite soil layer

A new analytical method is presented to study the axisymmetric Blot's consolidation of a finite soil layer. Starting from the governing equations of axisymmetric Blot's consolidation, and based on the property of Laplace transform, the relation of basic variables for a point of a finite soil layer is established between the ground surface (z= 0) and the depth z in the Laplace and Hankel transform domains. Combined with the boundary conditions of the finite soil layer, the analytical solution of any point in the transform domain can be obtained. The actual solution in the physical domain can be obtained by inverse Laplace and Hankel transforms. A numerical analysis for the axisymmetric consolidation of a finite soil layer is carried out.     

当地DFD方法在扑翼流动数值模拟中的应用

应用当地DFD（Domain-Free Discretization）方法对包含复杂运动边界的扑翼流场进行了数值模拟。该方法通过壁面法线方向的外插确定外部相关点上的流动变量值,同时强加相应的边界条件。应用这种方法,动边界流动的模拟可以在固定网格上实现,无需为了跟随物体的运动而在每个时间步上对网格进行实时更新。对三种拍动模式的双翅流场进行了数值模拟,升、阻力系数时间历程的计算结果与参考文献的实验数据吻合很好,验证了当地DFD方法处理复杂动边界问题的可靠性。最后,数值模拟了完整昆虫模型的扑翼流场,并详细分析了涡系结构和飞行机理。     

高速车削300M超高强度钢时的Al2O3 基陶瓷刀具磨损机理研究

使用Al2O3基陶瓷刀具对300M超高强度钢进行了干切削试验,采用电子扫描显微镜（SEM）观察刀具的磨损形貌,并通过能谱分析仪（EDS）测量了陶瓷刀具磨损微区的各元素含量,分析了陶瓷刀具的主要磨损机理.结果表明：陶瓷刀具磨损的主要机理为粘结磨损、磨粒磨损和氧化磨损.粘结磨损主要发生在前刀面上,且受刀具材料和工件材料接触点应力状态的影响.刀具前、后刀面的磨损边缘区易发生氧化磨损.     

分子伴侣GroE系统相互作用中结构与功能关系研究

根据大肠杆菌分子伴侣GroE系统的晶体结构数据，分析了GroEL顶端区域在其靶蛋白和GroES结合前后结构与功能的关系，讨论了GroEL的结构转变对其中心通道可及性和疏水特性的影响．提出了一种用以分析蛋白质之间相互作用趋势的方法，并用该方法分析了GroEL和GroES相互作用的3个氨基酸，得到了很好的结果。在此基础上，进一步用SwissPDBViewer对GroEL的核酸结合口袋进行了分析，结果表明活性中心与ADP磷酸键结合的残基Thr30可能与能量的传递有关．     

基于降阶解法的三维分层地基状态空间解

从以位移形式表达的三维弹性力学控制方程出发,经双重Fourier变换,并运用基于Cayley-Hamilton定理的降阶解法,推导出位移变量及其1阶导数的解,再利用物理方程求得单层地基的传递矩阵;结合边界条件和层间连续条件,进一步得到多层地基的状态空间解;编制相应程序进行数值分析,对多层地基中有软弱下卧层和坚硬下卧层时的沉降情况进行了比较和讨论．     

脉冲宽度法测电容及恒流源的选取

阐述了脉冲宽度法测电容的原理，给出了用运算放大器构成精密恒流源的2种电路，简要介绍了Uref的确定方法．