Quantum waveguide theory for hole transport in mesoscopic structures

A quantum waveguide theory is proposed for hole transport in the mesoscopic structures, including the band mixing effect. We found that due to the interference between the 'light' hole and 'heavy' wave, the transmission and reflection coefficients oscillate more irregularly as a function of incident wave vector geometry parameters. Furthermore conversion between the heavy hole and light hole states occurs at the intersection. (C) 2003 Elsevier Ltd. All rights reserved.

QUANTUM WAVE-GUIDE THEORY FOR MESOSCOPIC STRUCTURES

A one-dimensional quantum waveguide theory for mesoscopic structures is proposed, and the boundary conditions of the wave functions at an intersection are given. The Aharonov-Bohm effect is quantitatively discussed with use of this theory, and the reflection, transmission amplitudes, etc., are given as functions of the magnetic flux, the arm lengths, and the wave vector. It is found that the oscillating current consists of a significant component of the second harmonic. This theory is also applied to investigate quantum-interference devices. The results on the Aharonov-Bohm effect and the quantum-interference devices are found to be in agreement with previous theoretical results.

Analysis and Simulation of S-shaped Waveguide in Silicon-on-insulator

The simulation and analysis of S-shaped waveguide bend are presented.Bend radius larger than 30 mm assures less than 0.5 dB radiation loss for a 4-μm-wide silicon-on-insulator waveguide bend with 2-μm etch depth.Intersection angle greater than 20° provides negligible crosstalk (＜-30 dB) and very low insertion loss.Any reduction in bend radius and intersection angle is at the cost of the degradation of characteristics of bent waveguide and intersecting waveguide, respectively.

Heat Transfer Problems Induced By Multi-shocks Interaction

Numerical simulations of the multi-shock interactions observable around hypersonic vehicles were carried out by solving Navier-Stokes equations with the AUSMPW scheme and the new type of the IV interaction created by two incident shock waves was investigated in detail. Numerical results show that the intersection point of the second incident shock with the bow shock plays important role on the flow pattern, peak pressures and heat fluxes. In the case of two incident shocks interacting with the bow shock at the same position, the much higher peak pressure and more severe heat transfer rate are induced than the classical IV interaction. The phenomenon is referred to as the multi-shock interaction and higher requirements will be imposed on thermal protection systems.

不同小麦品质类型与生态环境关系的研究

小麦（Triticum aestivum L.）是世界上种植面积最大，总产量最高，食物加工种类最丰富的粮食作物，占世界人口35 ％－40 ％的人们以此为主要食物。因此小麦产量的高低和品质的优劣直接影响人们对食物需求的安全和满意程度，也影响着人类的营养平衡以及面粉和食品加工业的发展。随着生活水平的提高，人们对于小麦的品质越来越重视。培育优质专用小麦新品种，制定优质专用小麦品种品质生态区划，从而在不同程度上实现小麦的区域化种植和产业化经营具有重要的意义。 影响小麦品质的因素主要是遗传因素和环境因素，其中环境因素又包括各种自然生态因素和人为因素。研究表明，小麦品质的环境间的差异大于品种间的差异，气候条件是影响小麦品质的最重要的因子，小麦品质的地域间的差异反映出了小麦的品质区域分布规律。为了满足市场对不同品质小麦的需求，对小麦进行区域化研究具有重要的理论和现实意义。本研究结合四川的地理、气候特点，研究不同品质类型与生态环境的关系，为在复杂的生态环境内进行品质区划提供依据。 本研究首先根据四川省小麦种植区域的生态特点，在四川省多个典型生态区：川南丘陵的荣县、川西南高原的西昌、川西平原的双流布点种植，采用的小麦试验材料为不同品质类型：中筋小麦川育12、川育14、川育16由本所提供；弱筋小麦川麦32和强筋小麦川麦36由四川省农科院作物所提供。通过研究品质性状与品种及各个生态因子包括地点、土壤土质差异等的关系，明确不同生态环境中适宜种植的小麦品种类型，强筋小麦、中筋小麦更适合于在荣县、双流地区种植，弱筋小麦更适合于在西昌地区种植，为品种品质区划奠定基础。 其次，选择了本课题组育成的稳定中间品系，对其品质性状SDS沉降值进行了多年测定。分析了品质性状SDS沉降值与多种气候因子的相关性，结果表明SDS沉降值与日均温、日照时数成正相关，与降水量成负相关，为品质育种提供了理论依据。 此外，以中筋小麦新品种小麦川育14为材料，应用三元二次正交旋转回归模型设计试验，研究主要栽培因子播期、密度和施肥量对产量的影响，并建立函数模型。经计算机模拟寻优，筛选出了高产高效栽培组合措施，并确定了置信域。结合四川省不同的地理情况，在平原和丘陵地区分别进行实验，并各自建立了高产高效栽培组合措施，为川育14品种的推广提供了理论指导。 Wheat is one of the most important crops in the world. About 35%-40% people all over the world, take the wheat as their most important food. So the quality, as well as the quantity of the wheat makes a direct effect on people’s demands of food and their satisfaction. It also effects on human’s healthy, and the development of the Food processing industry. With the development of the living standard, people pay more attention to the quality of wheat. So, we set a special ecology zoning for wheat. It is significant to carry out planting the wheat in special zoning in varying degrees. The main factors affecting wheat quality are heredity and environment including many ecological factors and the factors in cultivation. As to the quality，the difference between ecology and cultivation is more important than the difference between special wheat. In so many factors, climate is the most important one. From the difference in quality between different zones，we can conclude the rule of distribution abort quality of wheat. Finding out the intersection of numerous wheat not only can meet the demand of food production，but also has important signification in theory and realism。In our research, according to the complex geography in Sichuan province, we study the relationship between numerous kinds of quality characters in wheat and the ecology. So, we can set a foundation for more research. In this research, firstly, we plant wheat in some typical ecological regions of SICHUAN province: RONGXIAN（south of SC）、XICHANG（south of SC）, SHUANGLIU(west of SC). The materials of the experiments: ChuanYu12, ChuanYu14, ChuanYu16(from our institute), Chuanmai32, Chuanmai36 (from the Chinese academy of agriculture sciences of Sichuan. Through the research on the relationship between the quality of wheat and those ecology factors, we can make a definition that which area is perfect matched with which kind of wheat. And it can satisfy the demand of people. Secondly, select many sorts of wheat from our research group. All of them are selected and bred more than 3 years(2003-2005). And we make every-year determination as well. We’ve gotten SDS value from those 9, and various data on factors of climate. We also got to know the relation ship between those numbers. Thirdly, use Chuanyu14 as material, the mathematical model of the relation between the production of wheat and main agricultural measures such as date, density and fertilizer. The model was established by association of three elements two return, rotate and regression. We set a suitable model and get a suitable method which can make high harvest. Based on various kinds of geographical regions in Sichuan province, we set different models which can be used in plain and hill. So, we can plant Chuan Yu 14 in Sichuan province under the result in research.

小麦抗旱生态分类中适合性聚类方法的研究

探索了适合于小麦品种抗旱生态分类的聚类方法 .选用 2 1个农艺性状和 15个冬小麦品种 (系 ) ,在聚类分析的各环节上 ,通过采用不同的策略 ,大规模进行了各种分类结果的比较 .结果表明 ,在与专家经验分类接近程度上 ,数据转换方法中 ,原始数据法依次大于普通相关阵基础上的方差极大正交旋转法、Promax斜交旋转法、主成份法 ;相似性度量上 ,欧氏距离大于马氏距离 ;聚类方式上 ,对应分析法和模糊聚类法大于最短距离法、最长距离法、类平均法 ;所有可组合的方法中 ,以对应分析法和直接用原始数据的模糊聚类法的分类结果最接近专家经验分类 .结合各方法理论上优缺点的分析与检验 ,认为这两种方法也是较理想的方法 .

水窖沉沙池结构形式试验设计

通过对单厢式矩形断面、单厢式梯形断面、迷宫式、旋流式等 4种结构形成的沉沙池沉沙效率对比试验表明 ,以迷宫式沉沙池效果最佳 ,平均沉沙效率可达 88.3%。此种结构形式的断面尺寸为 1m、宽 0 .4m ,迷宫室底部比集水渠低 0 .2 m,迷宫分成 5个小厢室 ,每个厢室长 0 .146 m,沉沙池首部的静水池深 0 .2 5 m

Electrochemical biosensors based on advanced bioimmobilization matrices

Biosensors have experienced rapid, extensive development. To maintain the bioactivity of biomolecules and to give the electrochemical output signal required, appropriate bioimmobilization matrices for biomolecules are critical.In this review, we describe some advanced membrane materials (including hydrogels, sol-gel-derived organic-inorganic composites and lipid membranes), introduce electrochemical biosensors based on bioimmobilization materials and describe their performance.Biosensors operating in extreme conditions and displaying direct electron transfer with electrodes based on these advanced membrane materials are attractive. Recent developments in nanomaterials include biosensors, so we emphasize the intersection of nanomaterials with advanced membrane materials in biosensors.

Investigation on the Voltammetric Behaviors in Planar Bilayer Lipid Membranes

In the TCNQ-modified BLM, the voltammetric response is different due to the different methods used to prepare the membrane forming solution. The direct and indirect dissolved methods result in irreversible and reversible responses respectively. These results can be explained by the different styles of the orientation of TCNQ in the membrane. The reversible response is controlled by the diffusion of electroactive species in the interior of the membrane. When MB is used to modify the BLM, very complex voltammograms are obtained. The intersection of the voltammetric curves can be regarded to be owing to the appearance of new phase in the membrane caused by MB. But it disappears at lower scan rate. Peak current increases with decreasing scan rate. This indicates that the resistance of the membrane at lower scan rate is lower than that at higher scan rate. Asymmetric curve of MB incorporated BLM is ascribed to the different rates of redox reaction at the two membrane/solution interfaces.

MECHANICAL-PROPERTIES OF PHENOLPHTHALEIN POLYETHER KETONE - YIELD STRESS, YOUNGS MODULUS, AND FRACTURE-TOUGHNESS

A series of tensile and three-point bending studies was conducted at various temperatures and loading rates using phenolphthalein polyether ketone (PEK-C). Yield stress, Young's modulus, fracture toughness, and crack opening displacement data were obtained for various conditions. In general, both yield stress and Young's modulus increase with decreasing temperature. However, the relationships between fracture toughness, loading rate, and temperature are very complex. This behavior is due to the simultaneous intersection of viscoelasticity and localized plastic deformation. The increased yield stress is the main factor contributing to the reduction in fracture toughness and crack opening displacement. The relationship between fracture toughness and yield stress are discussed. (C) 1995 John Wiley and Sons, Inc.

REDOX THERMODYNAMICS OF CYTOCHROME-C AT THE BARE GLASSY-CARBON ELECTRODE

Investigation of the redox thermodynamics of horse heart cytochrome c at bare glassy carbon electrodes has been performed using cyclic voltammetry with a nonisothermal electrochemical cell. The thermodynamic parameters of the electron-transfer reaction of cytochrome c have been estimated in different component buffer solutions. The change DELTAS(re)-degrees in reaction center entropy and the formal potential E-degrees' (at 25-degrees-C, vs. standard hydrogen electrode (SHE)) for cytochrome c are found to be -64.1 J K-1 mol-1 and 0.251 V in phosphate buffer, -64.8 J K-1 mol-1 and 0.257 V in Tris + HCl buffer, -65.6 J K-1 mol-1 and 0.261 V in Tris+CH3COOH buffer (pH 7.0, ionic strength 100 mM). The temperature dependence of the formal potential obtained in phosphate buffer with or without NaCl in the range 5-55-degrees-C shows biphase characteristics in an alkaline solution with an intersection point at ca. 44-degrees-C or 42-degrees-C, which should be due to a structural change in the protein moiety of cytochrome c. However, in acidic and neutral solutions only a monotonic relationship between E-degrees' and temperature is observed. The effect of the buffer component on E-degrees' for cytochrome c is also discussed.

装配机器人系统快速碰撞检测算法

提出一种面向操作手装配系统的快速碰撞检测算法。该算法以机器人运动学和空间解析几何为基础 ,将判断机械手手臂与障碍物是否发生碰撞问题转化为直线段与有界平面是否存在公共点的简单解析几何问题 ,并以 PU MA5 6 0操作手为例对算法加以说明。该算法不仅适用于静态的障碍物已知的环境 ,而且适用于障碍物运动规律已知的动态环境 ,减少了碰撞检测占用的时间 ,提高了路径规划的效率

一种测量深海应答器坐标的方法

提出一种适用于深海应答器坐标测量的方法:垂线相交法。这种方法利用立体几何原理,获得应答器坐标。即测量母船在距应答器适中的位置沿两条相互垂直的航迹航行,分别找到两条航迹上与应答器斜距最小的点,过这两个点在水平面上做两条垂线,交点的经纬度坐标就是应答器的经纬度坐标。分析了影响测量误差的重要因素,并提出测量原则以满足精度要求,使测量系统具有很好的鲁棒性。为提高测距精度,采用射线声学理论中的RRA算法对声线进行修正。仿真实验证明了垂线相交法的有效性。该测量方法对深度没有要求,简化了繁琐的现场操作和水声测量系统,具有很高的工程实用价值。

STL格式文件拓扑重建及快速切片算法研究

建立三角面片之间拓扑关系是提高分层切片效率的关键因素之一,提出基于标准模板库set容器的拓扑关系重建算法及快速切片算法,有效地去除了STL文件大量冗余数据,简化了数据的存储,该算法每一个三角面片在每一切平面内只求一次交点,切片完成后可直接得到封闭轮廓环,以减少在切片过程中对三角面片的遍历次数、排序次数及求交点计算量,简化了轮廓环的构造过程,从而有效地提高了算法的效率。

碳酸盐岩缝洞型储层地球物理响应特征及预测方法研究

Proven by the petroleum exploration activities, the karsts-fissure reservoir in carbonate rocks is significant to find out the large scale oil & gas field. They are made up of the four reservoir types: karsts-cave, karsts-crack, crack-cave and fracture-pore-cave. Each reservoir space and each reservoir bed has different features of reservoir heterogeneity and small scale of pore-crack-cave. The fracture-cave reservoir in carbonate rocks is characteristic by multi-types and long oiliness well. The reservoir shape is controlled by the irregular pore-crack-cave. The development level of fracture and karst-cave is the key element of hydrocarbon enriching, high productivity and stable production. However, most of Carbonate formation are buried deeply and the signal-ration-noise of seismic reflection are very low. It is reason why the fracture-cave reservoir are difficult to be predicted effectively. In terms of surveyed and studied lots of the former research outcome, The author applied the methods of synthetical reservoir geophysical prediction from two ways including macrosopic and microcomic technics in terms of the reservoir-cap condition, geophysics and geology feature and difficulty of prediction in carbonate rocks. It is guiden by the new ideas of stratigraphy, sedimentology, sedimentography, reservoir geology and karst geology. The geophysics technology is key technics. In aspects of macroscopic studies, starting off the three efficiencies of controlling the reservoir distribution including sedimental facies, karst and fracture, by means of comprehensive utilization of geology, geophysics, boring well and well log, the study of reservoir features and karst inside story are developed in terms of data of individual well and multiple well. Through establishing the carbonate deposition model, karstic model and fracture model, the macro-distribution laws of carbonatite are carried out by the study of coherence analysis, seismic reflection feature analysis and palaeotectonics analysis. In aspects of microcosmic studies, starting off analysis in reservoir geophysical response feature of fracture and karst-cave model according to guidance of the macroscopic geological model in carbonate reservoir, the methods of the carbonate reservoir prediction are developed by comprehensively utilization of seismic multi-attribution intersection analysis, seismic inversion restricted by log, seismic discontinuity analysis, seimic spectrum attenuation gradient, moniliform reflection feature analysis and multiparameter karst reservoir appraisement.Through application of carbonate reservoir synthetical geophysics prediction, the author r successfully develops the beneficial reservoir distribution province in Ordovician of Katake block 1in middle Tarim basin. The fracture-cave reservoir distributions are delineated. The prospect direction and favorable aims are demonstrated. There are a set of carbonate reservoir prediction methods in middle Tarim basin. It is the favorable basic technique in predicting reservoir of the Ordovician carbonate in middle Tarim. Proven by exploration drilling, the favorable region of moniliform reflection fracture and pore-cave and cave-fracture in lower-middle Ordovician are coincidence with the region of hydrocarbon show. It’s indicated that the reservoir prediction methods described in the study of Ordovician carbonate formation are feasible practicably.