摘要：Over the past several decades, great endeavors have been devoted to superhard materials research, among which two topics are of central focus. One is to understand hardness microscopically and reveal the controlling factors for superhardness, which can be used to guide the design of novel superhard crystals;the other is to synthesize superhard materials with enhanced comprehensive performance(i.e., hardness, fracture toughness,and thermal stability), with the ambition to synthesize materials harder than natural diamond. We proposed a microscopic understanding of the indentation hardness as the combined resistance of chemical bonds in a material to indentation, and established a microscopic hardness model for covalent and polar covalent crystals, which was further generalized to polycrystalline materials. Guided by the polycrystalline hardness model, we successfully synthesized nanotwinned cubic boron nitride and diamond bulks under high pressure and high temperature. These materials exhibit simultaneous improvement of hardness, fracture toughness, and thermal stability, designating a new direction for superhard materials research.

摘要：The quarter-circular caisson breakwater （QCB） is a new type of breakwater, and it can be applied in deepwater. The stability of QCB under wave force action can be enhanced, and the rubble mound engineering can be less than that of semi-circular breakwaters in deepwater. In order to study the wave force distribution acting on the QCB, to find wave force formula for this type of breakwater, firstly in this paper, the distribution characteristics of the horizontal force, the downward vertical force and the uplift force on the breakwater were gotten based on physical model wave flume experiments and on the analysis of the wave pressure experimental data. Based on a series of physical model tests acted by irregular waves, a kind of calculation method, which was modified by Goda formula, was proposed to carry out the wave force on the QCB. Secondly, the reliability method with correlated variables was adopted to analyze the QCB, considering the high correlation between wave forces or moments. Utilizing the observed wave data in engineering field, the reliability index and failure probability of QCB were obtained. Finally, a factor Q=0.9 is given to modify the zero pressure height above SWL of QCB, and wave force partial coefficient 1.34 to the design expressions of QCB for anti-sliding, as well as 1.67 for anti-overturning, were presented.

摘要：本文利用非线性极大单调算子值域的扰动结论,研究一类与广义p-Laplacian算子相关的、具Neumann边值条件的非线性椭圆方程的解的存在唯一性.同时研究这个唯一解与适当定义的非线性极大单调算子的零点之间的关系.进而设计一种迭代算法强收敛到这个唯一解本文采用新的构造算子和拆分方程的方法。

摘要：With the development of technology,the learning and memory functions of artificial memristor synapses are necessary for realizing artificial neural networks and neural neuromorphic *** to their high scalability performance,nanosheet materials have been widely employed in cellular-level learning,but the behaviors of nociceptor based on nanosheet materials have rarely been ***,we present a memristor with an Al/TiO_(2)/Pt *** electroforming,the memristor device showed a gradual conductance regulation and could simulate synaptic functions such as the potentiation and depression of synaptic *** also designed a new scheme that verifies the pain sensitization,desensitization,allodynia,and hyperalgesia behaviors of real nociceptors in the fabricated *** with these behaviors can significantly improve the quality of intelligent electronic *** fitting showed that the high resistance and low resistance states were consistent with the hopping conduction *** work promises the application of TiO_(2)-based devices in next-generation neuromorphological systems.

摘要：具有高三线态能级的交联空穴传输材料能够平衡发光层载流子的复合并有效抑制三线态激子的猝灭,对制备高性能溶液法有机电致发光二极管具有重要意义.本文设计合成了两种具有不同母核的新型交联空穴传输材料,V-p-DBT和V-p-DBF.与已报道的交联空穴传输材料V-p-TPD相比,二苯并噻吩和二苯并呋喃母核的引入增加了分子的扭转角,使两种化合物具有更高的三线态能级,分别为2.57和2.64 e V.通过瞬态荧光光谱证明它们能够有效地抑制三线态激子的猝灭.交联的空穴传输层表现出优异的抗溶剂能力和溶液工艺所需的理化性质.其中,基于V-p-DBF的绿色热活化延迟荧光有机发光二极管获得了79.94 cd A-1的最大电流效率和24.35%的最大外量子效率.这项工作为实现溶液法制备的有机电致发光二极管提供了一种新的分子设计策略.

摘要：针对高温工作状况下由滑阀几何形状引起的阀芯径向液压卡紧力进行了理论推导,进行了温度变化对阀芯与阀套配合间隙影响的温度场仿真分析,并对阀芯与阀套做了热应变分析,得到了滑阀顺锥与倒锥结构对阀芯受力的影响及油液、阀体温度不同情况下滑阀流道的温度场分布。通过对计算结果的分析,得出滑阀卡紧故障的原因,为滑阀设计提供了理论参考。

摘要：背景:单份脐血难以满足成人造血干细胞移植的要求,需对其进行体外扩增,这不仅需要较长的时间和较高的培养条件,而且容易导致干细胞自身分化,从而影响移植效果。目的:克隆人白细胞介素3基因cDNA,构建其真核表达载体并转导脐血CD34+细胞,观察白细胞介素3的表达情况。设计、时间及地点:细胞-基因组学体外实验,于2008年在承德医学院完成。材料:健康成人外周血由承德市中心血站提供,脐血由承德市妇幼保健院提供,提供者对实验均知情同意。方法:采集健康成人外周血,应用Ficoll密度梯度法分离单个核细胞,免疫磁珠法分离脐血CD34+细胞。提取白细胞介素3mRNA,应用RT-PCT扩增白细胞介素3cDNA,构建真核表达载体pcDNA3/IL-3。设立2组:实验组利用基因枪技术将pcDNA3/IL-3导入脐血CD34+细胞中,对照组未行转染。主要观察指标:采用人白细胞介素3ELISA试剂盒检测脐血CD34+细胞上清液中白细胞介素3水平。结果:扩增的白细胞介素3基因cDNA理论上应为616bp,实际PCR产物经琼脂糖凝胶电泳后,紫外线下可见预期大小的条带,反转录合成的cDNA完整。BamHⅠ和XbaⅠ双酶切后,电泳可见616bp的插入片段,与白细胞介素3基因序列相同。转染第1～7天,实验组脐血CD34+细胞上清液中白细胞介素3水平明显高于未转染对照组(t=3.46,P<0.05)。结论:白细胞介素3基因cDNA克隆成功,并成功构建了真核表达质粒pcDNA3/IL-3,pcDNA3/IL-3能在脐血CD34+细胞中短期有效表达。

摘要：根据液压集成块的结构及其设计特点,建立了集成块布局优化中带性能约束的多目标优化数学模型,并利用小生境遗传模拟退火算法对提出的数学模型进行了求解。实例表明,利用小生境遗传模拟退火算法可以很好完成集成块的布局优化,为集成块布局设计提供了参考依据。

摘要：In this paper, the smooth connection between two B-spline surfaces is discussed. First, a brief proof of some simple sufficient conditions of Go and G1 continuity is given. On this basis, a novel method for Go or G1 connection between two adjacent B-spline surfaces is presented. A reparameterization step is firstly taken for one of the surfaces such that they have the same parameterization in v direction, then, adjust their boundary control vertices to make them Go or Gl connected. The GI connection parameter is determined by an optimization problem. Compared with the existed methods, our method is simple and easy to be used in practice.

摘要：由于Cd有毒性,AgSnO_2触头材料逐渐取代了AgCdO成为新型触头材料,但由于AgSnO_2触头材料中的SnO_2近乎绝缘,使得触头材料的接触电阻增大,故改善SnO_2的导电性是急需解决的重大难题。本文提出了一种简单的、低成本的La掺杂AgSnO_2触头材料的设计方法。采用模拟计算的方法,利用第一性原理的密度泛函理论平面波超软赝势法,建立了SnO_2以及不同比例La掺杂的SnO_2超晶胞模型,在对其进行几何优化之后分别研究了La掺杂比为50%、25%、16.67%、12.5%、8.34%的SnO_2材料的电子结构,并研究了其晶格参数、能带结构和态密度等。结果表明,掺杂后材料晶胞体积变大。La的5d轨道进入导带,使得导带底向低能端移动,禁带宽度变小。最终得出La掺杂比为16.67%时导电性最佳。最后进行了不同掺杂比下触头材料的电接触性能试验,得到了接触电阻和燃弧能量等电接触性能参数并验证了模拟结果。因此,本文的研究为触头材料的发展和应用提供了理论依据。