FOR E WORD

(?)t was a great honout of mine to be invited to joio the International Organising Committee of the 8th International Conference on Surface and Colloid Seience (the 8th ICSCS).I was very pleasedto be able to assist in the organisation of the conference by advertising the conference in threenational Chinese journals and forwarding the Circular and Call for Papers to various univesities,companies and research institutions in China.As part of the response to all these efforts,quite a number of papers from my colleagues in Wuhan University of Technology (WUT) weresubmitted to and accepted by the conference.For various reasons,most of the authors will not be able to attend the conference and unfortunately,no proceedings of the conference will be published.Therefore,I think it is necessary for me to compile all these papers into a specialissue of the Journal of WUT and bring them to the conference for the purpose of academicexchanges.I consider this as part of my responsibility of being a member of the Intern     

Study on the Dynamic Characteristic of Lathe Headstock

In order to provide reliable data for the dynamic design or modification of a tool machine,the dynamic character- istics of the headstock,which is the main component to bear moment,must be obtained precisely.In the paper,the method based on the combination of calculation mode and experiment mode is proposed to analyze the dynamic characteristics of the headstock.The modal parameters and the mode shapes are calculated by ANSYS7.1 software.According to the FEM calculating results,the ex- periment parameters can be selected correctly.The modal parameters of the headstock have to be calculated and identified precisely. On the basis of these modal parameters,the faults of the headstock are shown and its weak points of design are illustrated.A con- clusion is drawn that some reasonable reinforce positions could greatly improve the dynamic characteristics of the system and this ap- proach is proved to be precise and reliable.     

Polarization and absorption principle of corona virus in the electric field

The polarization and absorption principle of corona virus in the electric field is presented. It is expressed by the mathematic differential equation based on the physical model. According to the parameters of the dipole moment of virus, the electric field force exerted by the external electric field can be calculated. According to the parameters of size, mass and elastic modular, etc. , the moment of inertia of virus can be calculated. According to the viscosity of tissues, the resistant force when virus rotates can be calculated. According to the balance condition of relaxation polarization, when the drive force equals to the resistant force, the rotating or swaying frequency of virus can be calculated. According to the heat producing condition such as friction, the temperature rising of virus can be calculated. When the temperature exceeds a certain threshold, virus would be inactivated. Through the calculation, it is found that the movement type of the virus depends on the intensity and frequency of the external electric field, which are the effects of ＂intensity widows＂ and ＇＂ frequency windows＂. It also gives approximate calculation of the temperature rising of the virus according to this model. The vitro experiment confirms the reasonability of this model. The electric fields of different densities of a certain frequency are applied to the solution of avian infectious bronchitis virus. Through the toxicity experiment of the SPF chicken embryo, it is found that the toxicity is decreased exceedingly with a certain intensity of the applied voltage. EID50 decreases from 6. 70/0. 2 mL to 2.66/0. 2 mL. It is proved that the avian infectious bronchitis virus can be inactivated with a certain low frequency and low-density electric field.     

A new method determining safe thickness of karst cave roof under pile tip简

Cave roofs are used to support pile foundation in many engineering projects. Accurate stability analysis method of cave roof under pile tip is important in order to ensure the safety of the pile foundation structure. Firstly the mechanical model to analysis the stability of cave roof under pile tip is founded aiming to solve the problems that the simplified mechanical model has. Secondly, the boundary of cave roof is simply supposed to be supported according to the integrity of the rock mass in the boundary of cave roof. Thirdly, based on the theory of plates and shells, the simplified model is calculated and the theoretical calculation formula to determine the safe thickness of cave roof under pile tip can be obtained when the edges of the cave roof are simply supported. In the end, the analysis of the practical engineering project proves the feasibility and the rationality of the method which can be a new method to calculate the safe thickness of cave roof under pile tip.     

Application of non-equal interval GM （1,1） model in oil monitoring of internal combustion engine

The basic difference non-equal interval model GM（1,1） in grey theory was used to fit and forecast data series with non-equal lengths and different inertias, acquired from oil monitoring of internal combustion engines. The fitted and forecasted results show that the length or inertia of a sequence affects its precision very much, i. e. the bigger the inertia of a sequence is, or the shorter the length of a series is, the less the errors of fitted and forecasted results are. Based on the research results, it is suggested that short series should be applied to be fitted and forecasted; for longer series, the newer datum should be applied instead of the older datum to be analyzed by nonequal interval GM（1,1） to improve the forecasted and fitted precision, and that data sequence should be verified to satisfy the conditions of grey forecasting.     

ELASTOPLASTIC ANALYSIS OF THICK-WALL CYLINDER CONSIDERING THE MATERIAL＇S DILATANCY CHARACTER

Impermeable bentonite or its mixtures have been proposed as candidate materials to be used in the geotechnical disposal of radioactive nuclear waste. These materials are filled in the space between a canister containing radioactive nuclear waste and an underground chamber to absorb the radionuclide emitting from the canister and simultaneously retard its migration accompanying the permeation of underground water to prevent the surrounding environment from pollution. On the basis of the established elastoplastic strain-hardening mechanical model considering the material‘s dilatancy character, the authors carry out the stress-strain analysis of a thick-wall cylinder in a plane strain state subjected to a pressure difference between internal and external pressures. The analysis may be expected to be a theoretical basis for developing a coupled shear and permeability test apparatus for conducting a permeability test along a sheared plane in a specimen. The apparatus will be used to study the effects of shear strain on the variation of geotechnical materials′ permeability coefficient in order to evaluate the influence of shear strain caused by nonuniform deformation and/or earthquake on the long-term safety of the disposal system of radioactive nuclear waste. The theoretical analysis methods in this paper can be directly spread to the analysis of the deformation and stability of tunnels or roadways driven in soft soils or high moisture-bearing soft rocks.     

Perturbation analysis on post-buckling behavior of pile

The nonlinear large deflection differential equation, based on the assumption that the subsoil coefficient is the 2nd root of the depth, was established by energy method. The perturbation parameter was introduced to transform the equation to a series of linear differential equations to be solved, and the deflection function according with the boundary condition was considered. Then, the nonlinear higher-order asymptotic solution of post-buckling behavior of a pile was obtained by parameter-substituting. The influencing factors such as bury-depth ratio and stiffness ratio of soil to pile, slenderness ratio on the post-buckling behavior of a pile were analyzed. The results show that the pile is more unstable when the bury-depth ratio and stiffness ratio of soil to pile increase, and although the buckling load increases with the stiffness of soil, the pile may ruin for its brittleness. Thus, in the region where buckling behavior of pile must be taken into account, the high grade concrete is supposed to be applied, and the dynamic buckling behavior of pile needs to be further studied.     

PERSPECTIVE OF COAL DEVELOPMENT OF CHINA IN THE EARLY 2000＇S

According to the Researches on Coal Development Strategies in China(1991-2020),the production scale of coal in China will increase to 2100 Mt in the year2020 and the district layout of coal development and production will be diverted fromthe east to the central-west step by step. In addition, the multi-ply running structure mines of the nation ,the local and the village and town combined with production scales of the large, the middle,and the small will be kept. However,the technique of mining will be improved greatly.     

顺从运动中机器人振动的最优控制(英文)

0 Introduction Many robot applications, such as assembly, require the endpoint of the manipulator to be mechanically coupled to external environment during some phase of the operation. The endpoint compliance can be implemented in many different schemes, and Whitney provides an overview of compliant motion control. In order to regulate the contact force between the endpoint and the environment, a force sensor is placed at the endpoint of the robot to measure the contact     

Wind speed prediction by chaotic operator network based on Kalman Filter

A novel prediction network composed of some chaotic operators is proposed to predict the wind speed series.Training samples are constructed by the theory of phase space reconstruction.Genetic algorithm is adopted to optimize the control parameters of chaotic operators to change the dynamic characteristic of the network to approach to the predicted system.In this way,the dynamic prediction of wind speed series can be completed.The wind acceleration series can also be predicted by the same network.And the prediction results of both series can be fused by Kalman Filter to get the optimal estimation prediction result of the wind speed series,which is superior to the result obtained by each single method.Simulation results show that the prediction network has less computation cost than BP neural network,and it has better prediction performance than BP neural network and autoregressive integrated moving average model.Kalman Filter can improve the prediction performance further.     

Capillary Micro-Flow Through a Fiber Bundle（Ⅰ）

The present work considered the capillary micro-flow through a fiber bundle. The resin heights in the fiber btundle as a function of time were used to detemine the experimental valises of capillary pressure and the permeability by the nonlinear regression,fitting method. The fitting curves showed a good agreement with experiments. However, these values of capillary pressure from short-time experiments were much lower than the theoretical results from the Yang-Laplace Equation. More accurate capillary presswre was predicted from the presented long-run experiment.     

基于毛细管连通率和水力迂曲度的碳酸盐岩渗透率分形模型

碳酸盐岩非匀质性强,孔隙结构呈现出连通率低、迂曲度高的典型特征。而以往的渗透率分形模型假设岩石孔隙由相互不干扰的毛细管束组成,忽略了复杂成岩过程中胶结作用导致的毛细管连通性降低和迂曲度增大的情况,难以准确评估低渗碳酸盐岩的渗透特性。针对渗透率被高估的研究现状,利用满足阿波罗填充的毛细管束分形模型,提出了毛细管连通率表征进出口毛细管过流面积损失,并引入曲折度指数来反映岩石的实际水力迂曲度,最终建立基于连通率、水力迂曲度的碳酸盐岩渗透率分形模型。参数敏感性分析发现,孔隙度相同粒径不同的碳酸盐岩,渗透率均随着孔径增加而增加,同时相同粒径岩石随着孔隙度的增大,渗透率对孔隙度变化的敏感性降低。考虑曲折度指数的水力迂曲度计算值与实验压汞法测定值更为一致,表明提出的碳酸盐岩渗透率分形模型能够更好地预测碳酸盐岩真实渗透率。     

编织预制件渗透率测量方法的比较研究

采用单向和径向流动测量了三维编织预制件的渗透率，比较研究了测量三维编织预制件渗透率的特点，分析了纤维体积含量、渗透率方向、注入压力在2种测试方法中的作用。实验结果表明：径向法适用于较低纤维体积含量，通过提取流动前沿轮廓能够确定渗透率方向，径向法中注入压力为0．1—0、3MPa较适合；单向法适用于较高纤维体积含量，仅能测量2个方向的渗透率，而不能确定主渗透率方向，三维编织预制件渗透率测量采用2种方法相结合，单向法测量渗透率的大小，径向法测量主渗透率的方向。     

纤维表面处理对RTM工艺及其制品的影响

采用RTM工艺分别对2种玻璃纤维试样进行充模实验,一种玻璃纤维试样未经任何处理,另一种试样用丙酮浸泡24 h后去除其表面上胶剂。通过实验研究这2种纤维试样的可浸润性和渗透率,同时分别对充模实验所得的2种纤维增强复合材料样板进行拉伸性能测试,最后用DMA和SEM对这2种样板的界面性能进行分析研究。得出结论:玻璃纤维经丙酮表面处理后,其可燃物含量降低,可浸润性提高,渗透率增大,其制得的复合材料样板空隙率减小,但树脂与纤维的界面结合强度下降,样板拉伸强度降低。     

玄武岩纤维加固粉土性能试验研究

针对北京大兴某地区粉土采用了短切玄武岩纤维作为添加剂进行了改良,采取纤维长度、纤维掺入比以及压实度作为变量对纤维土进行了固结快剪试验、压缩试验、变水头渗透试验,结果表明:经过改良后的粉土在抗剪强度、压缩性能以及渗透性能等方面均得到了提高;在相同纤维长度情况下,各方面性能增强在4‰纤维掺量内呈衰减式增长,对强度和压缩性的改良以3‰为最佳,对于渗透性能以2‰最佳;在相同掺量的情况下,对于抗剪强度和压缩性能3 cm纤维最佳,对于渗透性能2 cm纤维最佳;在最优掺入方案下纤维土的压实度与压缩系数、渗透系数存在二次幂函数关系,压缩系数与3 cm纤维掺入量也存在四次幂函数关系.     

薄壁结构C50抗渗防裂混凝土试验

根据薄壁结构混凝土的特点，利用中热硅酸盐水泥优化设计出了C50抗渗防裂混凝土配合比。试验结果表明：聚丙烯纤维、钢纤维通过单掺或混掺配制的混凝土28d抗压强度均达到56MPa，抗渗等级P12，满足混凝土的抗渗防裂要求；且单掺聚丙烯的纤维混凝土表现出更优异的抗渗透能力和抗裂性能。SEM微观结构显示，掺膨胀剂混凝土中的水泥石结构均匀密实，产生的钙矾石水化产物丰富，对水泥石收缩具有明显补偿作用，提高了薄壁结构混凝土的抗渗防裂能力。     

孔喉体积定量预测新方法

压汞数据估算的孔喉大小能评价圈闭的封闭能力和解释地层烃类聚集的有利部位，是储层研究中的一个重要参数。但是，压汞测试昂贵，因而一个地区这种资料少，而常规岩心分析资料如孔隙度和渗透率数据往往比压汞测试资料丰富很多，是否可以根据岩样的孔隙度和渗透率的大小反演岩样的孔喉体积分布，或反演毛管压力曲线？利用分形几何学的原理和方法，实现了利用常规岩心分析资料如孔隙度和渗透率等反演毛管压力曲线，建立孔喉体积分布预测模型，为非取心井段的孔隙结构研究开避了新途径。通过实际资料验证，该方法预测结果精度较高。     

Development of sintered Ni-Cu wicks for loop heat pipes

The present study fabricated a series of capillary wicks for loop heat pipes (LHPs), using two different methods, the cold-pressing sintering and direct loose sintering, and experimentally investigated the effect of different methods, compositions and sintering parameters on their properties in terms of porosity, permeability and pore radius. Porosity and pore radius were measured by the Archimedes method and Scanning Electron Microscope (SEM), respectively. Permeability of the wicks was compared by calculation using empirical equation. Results show that capillary wicks were successfully fabricated by using two different methods; the optimal capillary wick was found to be sintered at 650°C for 30 min, using direct loose sintering technique, with 90% nickel and 10% copper. The wicks could reach the porosity of 70.07% and the permeability of 10⁻¹³ m² order, with mean pore radius of 0.54 μm. Supported by Shandong Provincial Program of Science and Technology Development (Grant No. 2007GG1HZ06004)     

单井注气吞吐过程中油气饱和度分布研究

建立了相对渗透率和毛管压滞后模型,对已有的黑油模型进行了改进,使得相渗和毛管压力在实际的油藏模拟中更加精确地体现出来,并使改进后的模型能有效地反映注气吞吐过程的真实动态。基于改进的黑油模型,对单井注气吞吐全过程的三个阶段：注气阶段、关井平衡阶段、开井采油阶段,油气的饱和度分布规律进行了模拟计算和结果分析,研究结果对实际的水平地层单井吞吐均具有一定的指导意义和作用。     

凝析油气体系流固耦合相平衡计算新方法

在分析了孔隙介质内表面吸附、毛细凝聚、毛细管压力等界面物理化学效应和应力变形对孔隙介质中流体相态影响的现象学特征和影响机制的基础上,通过在大尺度空间常规流体相平衡热力学模型中引入界面物理化学效应的影响,同时通过高才尼-卡尔曼方程将毛细管半径与孔隙介质储渗特性的应力敏感性研究成果相关联,建立了同时考虑储层应力变形和界面物理化学效应影响的微孔隙尺度条件下的低渗特低渗凝析气藏多相流体流固耦合露点压力、p-T相图及定容衰竭相平衡热力学计算模型.该模型的初步应用表明,其相态模拟计算结果能更为合理地解释孔隙介质环境中的凝析油气体系相态特征实验研究结果.