微波遥感的发展与应用

微波遥感作为遥感技术的一个分支,是20世纪70年代发展起来的一门年轻的学科.着重以我国微波遥感发展的历程为例,回顾了三十多年来微波遥感领域学术与技术的迅速发展,比较分析了微波遥感对于可见光和红外遥感有着不可比拟的优越性,因而在海洋、冰雪、大气、测绘、农业、灾害监测等方面都有着广泛的应用.同时提出了目前我国在微波遥感领域存在的若干不足并指出了今后的研究方向.     

Undrained dynamical behavior of Nanjing flake-shaped fine sand under cyclic loading

A series of dynamic behavior tests on Nanjing flake-shaped fine sand were performed by using the WFI cyclic triaxial apparatus made in England. The dynamic behaviors of Nanjing flake-shaped fine sand under different static deviator stress levels and cyclic stress ratios were studied. Through comparing the effective stress path under cyclic loading with static loading, the processes of liquefaction of saturated Nanjing flake-shaped fine sand with development of dynamic pore-water pressure, including the initial compact state, compression state and dilative state, were investigated. The variation of the shear stiffness with the number of cycles and cyclic strain was investigated by analyzing the secant shear modulus in each unload-reload loop of dynamic stress-strain relationship. And by means of the exponential function, the empirical equations of the relationship between secant shear modulus Gsec, shear modulus ratio Gsec/Gmax and cyclic strain ε were established based on series of test results. The results show that according to different combinations of static deviator stress and cyclic stress, two kinds of failure patterns with deviator stress reversal or no deviator stress reversal are observed in the samples tested in this series, including cyclic mobility and the failure of accumulation residual strain. In addition, the degradation of dynamic shear modulus is due to the development of vibration pore-water pressure and it is observed that the shear modulus reduces with the progressive number of cycles.     

Sand deposit-detecting method and its application in model test of sand flow

Against the background of the sand-flow foundation treatment engineering of Guangzhou Zhoutouzui variable cross-section immersed tunnel, a kind of sand deposit-detecting method was devised on the basis of full-scale model test of sand-flow method. The real-time data of sand-deposit height and radius were obtained by the self-developed sand-deposit detectors. The test results show that the detecting method is simple and has high precision. In the use of sand-flow method, the sand-carrying capability of fluid is limited, and sand particles are all transported to the sand-deposit periphery through crater, gap and chutes after the sand deposit formed. The diffusion range of the particles outside the sand-deposit does not exceed 2.0 m. Severe sorting of sand particles is not observed because of the unique oblique-layered depositing process. The temporal and spatial distributions of gap and chutes directly affect the sand-deposit expansion, and the expansion trend of the average sand-deposit radius accords with quadratic time-history curve.     

Field study of plastic tube cast-in-place concrete pile

The compositions, technical principles and construction equipments of a new piling method used for ground improvement plastic tube cast-in-place concrete pile were introduced. The results from static load tests on single piles with different forms of pile shoes and on their composite foundations were analyzed. The distribution patterns of axial force, shaft friction and toe resistance were studied based on the measurements taken from buried strain gauges. From the point of engineering application, the pile has merits in convenient quality control, high bearing capacity and reliable quality, showing higher reasonability, advancement and suitability than other ground improvement methods. The pile can be adopted properly to take place of ordinary ground improvement method, achieving greater economical and social benefits.     

予岂好辩哉?予不得已也——《孟子》一书对孟子辩者形象的塑造

长于论辩,是《孟子》散文的突出特征.《孟子》一书通过对孟子言行的记录,不仅表现了孟子的思想和理论,亦成功地为后人展示了一个鲜活的辩者形象.孟子与时人的论辩涉及政治、经济、伦理道德、哲学等诸多领域;通过对旁征博引、因势利导、诱敌入彀、归谬反驳、执经行权等论辩方法的娴熟驾驭,表现出鲜明的个性特点.     

爱的阶梯——析克里斯蒂娜·罗塞蒂诗歌主题变换

克里斯蒂娜一生孤独迷离,她弃绝人间的舒适享乐全心追求永恒的精神快乐.诗歌是她生活的真实写照:从初恋失败,父亲病逝,到中年全方位的社交活动,再到孤独的晚年隐退.她的诗歌也呈现出统一协调的三部曲:从温婉细腻的抒情诗,到内涵丰富的叙事诗,再到热烈苍凉的祈祷文.爱是诗人背后最隐秘的缘由.为寻求心灵的平静,她试图在爱中找到永恒,却一次次被爱推着向前走:从人世爱恋到社会爱心,再回归上帝.     

Influencing factors of compressive strength of solidified inshore saline soil using SH lime-ash

Through unconfined compressive strength test,influencing factors on compressive strength of solidified inshore saline soil with SH lime-ash,ratio of lime-ash(1-K),quantity of lime-ash,age,degree of compression and salt content were studied.The results show that because inshore saline soil has special engineering characteristic,more influencing factors must be considered compared with ordinary soil for the perfect effect of solidifying.     

一种风幕式抽油烟机的实验研究

通过对厨房油烟扩散机理的分析和模型实验,研究了影响油烟控制的各种因素,采用实验与计算流体力学仿真技术相结合的方法,对不同情况下油烟罩的油烟控制性能进行了比较、分析,设计出了一种新型节能型抽油烟机。     

Creep testing and viscous behavior research on carbon constructional quality steel under high temperature

Creep tests under at a certain temperature and different stress levels were performed on two carbon constructional quality steels at a certain stress level and different temperatures,and their creep curves at high temperature were obtained based on analyzing the testing data.Taking 45 steel at a certain temperature and stress as the example,the integral creep constitutive equation and the differential stress-strain constitutive relationship were established based on the relevant rheological model,and the integral core function was also obtained.Simultaneously,the viscous coefficients denoting the viscous behavior in visco-plastic constitutive equation were determined by taking use of the creep testing data.Then the viscous coefficients of three carbon steels(20 steel,35 steel and 45 steel) were compared and analyzed.The results show that the viscosity is different due to different materials at the same temperature and stress.     

Optimization of rheological parameter for micro-bubble drilling fluids by multiple regression experimental design

In order to optimize plastic viscosity of 18 mPa·s circulating micro-bubble drilling fluid formula,orthogonal and uniform experimental design methods were applied,and the plastic viscosities of 36 and 24 groups of agent were tested,respectively.It is found that these two experimental design methods show drawbacks,that is,the amount of agent is difficult to determine,and the results are not fully optimized.Therefore,multiple regression experimental method was used to design experimental formula.By randomly selecting arbitrary agent with the amount within the recommended range,17 groups of drilling fluid formula were designed,and the plastic viscosity of each experiment formula was measured.Set plastic viscosity as the objective function,through multiple regressions,then quadratic regression model is obtained,whose correlation coefficient meets the requirement.Set target values of plastic viscosity to be 18,20 and 22 mPa·s,respectively,with the trial method,5 drilling fluid formulas are obtained with accuracy of 0.000 3,0.000 1 and 0.000 3.Arbitrarily select target value of each of the two groups under the formula for experimental verification of drilling fluid,then the measurement errors between theoretical and tested plastic viscosity are less than 5%,confirming that regression model can be applied to optimizing the circulating of plastic-foam drilling fluid viscosity.In accordance with the precision of different formulations of drilling fluid for other constraints,the methods result in the optimization of the circulating micro-bubble drilling fluid parameters.     

可拓学共轭理论在专利资源分析中的运用

本文采用虚部与实部的物质性、软部与硬部的系统性、潜部与显部的动态性、负部与正部的对立性4个方面的分析方法,研究专利事物之间相互对应以及相互关联的共轭关系,探求专利创造、保护、运用的各种矛盾问题的解决方法,开拓专利技术创新之路,在潜在风险隐患进行未雨绸缪的专利预警中、在现有资源进行有深度宽度的专利挖掘中、在科技成果进行有力度速度的专利创造中、在世界市场进行有角度尺度的专利布局中、在未来发展进行有高度广度的专利导航中,进一步增强企业参与世界经济大循环的竞争力,实现专利应有的市场价值和社会价值.     

关于受控扩散过程的动力学

主要考虑在给定初始条件下构形变量的时间演化可由受控扩散描述的有限自由度动力系统.基于随机控制一般理论,引入受控扩散的随机作用量的两个适当形式.通过离散该随机作用量,导出系统受控扩散的广义坐标表示的动力学方程,该方程连同连续方程一起精确描述扩散运动的概率进程.     

基于WPA的无线局域网安全性分析

本文详细分析了最新的无线安全加密体制WPA的规范并对其安全性做了分析,结合目前广 泛使用的WEP加密体制的弱点,分析WPA的相比与WEP的优点,指出了WPA代替WEP成为无线安全屏 障的必然。     

立方准晶的反平面问题与Ⅲ型裂纹问题

发展了立方准晶材料的断裂理论 .通过应用Fourier分析和对偶积分方程理论 ,得到了立方准晶材料Ⅲ型裂纹问题的精确解析解 ,并由此确定了位移与应力场 ,应力强度因子和应变能释放率 .结果表明 ,应力强度因子与材料常数无关 ,而应变能释放率依赖于所有的材料常数 .这些为研究此新固体材料的变形和断裂提供了重要的信息 .     

建筑存量系统分析与模拟方法

建筑存量可持续性研究的基本观点是将特定范围的建筑群体视为具有物质、经济、文化属性的开放系统,通过量化模拟方法考察其与环境的相互作用.首先分析建筑存量及其子系统(单体建筑)的层次结构、动态特征,以及与环境间的输入输出过程.进而讨论建筑存量系统模拟的几项关键问题,包括参考建筑的定义和描述、建筑使用阶段的更新过程、时间上的变化层面等.在此基础上,介绍基于递归过程估算建筑存量系统材料、能量流量的理论模型.     

FMS中加工质量故障预报的新方法

对引起加工质量故障的原因进行了研究,建立了用于加工中心加工质量故障分析的与/或故障树,提出了隐加工质量故障(FMQF)的概念和由·FMQF 找出制造系统故障的决策树方法.本文在模糊理论基础上,提出了隐加工质量故障识别的新方法,用这种方法可以根据控制图的变化进行设备状态估计.基于以上研究,建立了可用于柔性制造系统隐加工质量故障预测和预报的专家系统.     

基于ABAQUS的隧道二衬台车模板的数值模拟

针对贵州羊胆山隧道的二衬台车在浇筑混凝土过程中模板的内力和位移是否满足现行规范要求的问题,应用数值模拟软件ABAQUS进行了模拟计算,并到现场进行了实际测量,将实测侧压力值施加到模型上,得出内力及位移结果.计算及实测结果表明,模板弧度变化最大的位置受到的压力也最大;连接板与肋板、台车结构与连杆相连接处是结构最为薄弱的地方,故在各连接处应确保足够强度;连接处的肋板对限制模板变形起到了重要作用.     

钢的退火软化机理

分析了钢的退火软化机理,指出钢的退火软化应从固溶体强化、位错强化、细晶强化等方面降低对铁素体基体的硬化作用,同时使钢呆的出的碳化物球状化、对Ｈ１３钢退火碳化物颗粒的平均直径、弥散度一硬度的 研究表明在碳化物体积分数一定时,硬度是碳化物颗粒平均直径的函数,颗粒直径越大,退火硬度越低     

等离子体引发接枝聚合丙烯腈对聚乙烯表面改性的研究

研究了等离子体引发单体接枝聚合对聚合物的表面改性.选取PE为聚合物底材接枝丙烯腈,研究了接枝反应条件对接枝率的影响规律.反应温度愈高,接枝率愈大,当反应温度达到溶液的沸点时,接枝率急剧增大;随着单体浓度的增大,接枝率几乎呈现出线性增长的趋势;接枝率随反应时间的延长而增大.溶剂对接枝反应有较大的影响,当选用(甲醇+水)作为混合溶剂时,接枝率随着水与醇的体积比R(R=V(H₂O) / V(C_nH_2n+1OH))的增加而增加.当选用(乙醇+水)或(异丙醇+水)作为混合溶剂时,水醇体积比R为零(即溶剂为纯乙醇或异丙醇时)接枝率最大,当溶剂中有水参与时,接枝率下降.并利用ATR FTIR分析证明了丙烯腈单体接枝到聚合物薄膜样品表面.     

金属粉末-火焰热喷涂技术及应用

介绍了热喷涂技术、原理及分类,重点介绍了金属粉末-火焰热喷涂技术、原理、主要设备、材料及其应用。