内燃机装配料信息结构的数学模型及系统变型

基于文［１］提供的模式，本文旨在建立内燃机装配物料管理信息系统的数学模型，并采用面向对象的程序设计技术，根据不同的驱动因素实现产品的系统变型。

CBR技术在参数化变型设计系统中的研究

实例推理 CBR 技术是新兴的人工智能技术 .本文通过分析参数化绘图的原理和方法 ,讨论了基于实例推理技术的变型设计以及如何实现基于实例推理技术的参数化绘图 ,采用高级语言 VisualC+ +与 UGII数据接口技术 ,实现了原型系统的参数化变型设计 .

蠕变型复合防水系统及其耐久性能研究

介绍了蠕变型复合防水系统的材料选择原则,分析其得到大力推广应用的原因。以非固化橡胶沥青防水涂料+SBS改性沥青防水卷材、热熔橡胶沥青防水涂料+SBS改性沥青防水卷材两种蠕变型复合防水系统为例,介绍了老化处理后涂料与卷材的剥离强度试验及其结果,分析了涂料与卷材的结合效果以及实际应用优势。

含模块化多电平变流器的分布式发电系统动态特性分析

根据模块化多电平变流器(modular multilevel conv-erters,MMC)的工作原理和拓扑结构特点以及逆变型分布式发电系统(distributed generation,DG)的运行特点,建立了由MMC构成的DG等值系统及其交流电流控制器数学模型。运用PSCAD分析了基于MMC的DG系统动态特性,发现当直流电压大幅波动时,DG交流电流和输出功率同样出现了大幅波动的情况。针对这一问题,提出了改进的交流电流控制器,并通过仿真证明了该控制器的有效性。

一种基于动态约瑟夫遍历和比特平面交叉置乱–扩散的彩色图像加密算法

本文提出一种基于动态约瑟夫遍历和比特平面交叉置乱–扩散的彩色图像加密算法。首先,对图像的各行像素值求和量化,作为约瑟夫遍历的起点,使得约瑟夫遍历依赖于明文图像;利用斜帐篷混沌系统生成混沌序列并进行量化,得到约瑟夫遍历的步长,然后实现彩色图像的像素位置的约瑟夫遍历,达到置乱的效果。其次,将置乱后的图像像素值进行高低四比特分裂,利用变型Chen混沌系统生成的改进混沌序列对高低四比特序列进行动态置换,初步改变像素值。最后,通过变型Chen混沌系统生成的伪随机灰度值序列对初步加密的密文图像进行扩散操作,进一步增强加密算法的安全性。实验仿真结果表明,该算法加密效果优良,具有密钥空间大、密钥和明文敏感性高、密文图像统计性能好等优点,能够很好地抵御穷举攻击、统计分析攻击、差分攻击和选择明文、已知明文攻击等。

基于CSM的快速化产品设计方法的研究

基于零部件供应商管理 (CSM )的快速化产品设计系统是以变型设计系统为设计辅助工具 ,以零部件和供应商管理为信息管理工具 ,通过网络化的招标、投标管理选择出最佳的供应商 ,从而实现产品的快速化设计。首先介绍了该系统的结构 ,分析了各组成模块的作用。系统的网络计算模式为三层模式 ,包括“用户浏览器层”、“应用服务器层”和“数据库服务器层”。系统地概括了“供应商信息管理”所涉及到的信息内容及其逻辑结构。最后 ,介绍了该系统的初步实现情况。

Dynamic Response of IBM3370 Slider in High Density Recording Systems

A liquid lubricated head disk system is introduced. Subjected to high shear rate the rheology of the ultra thin film is different from that of the bulk continuum theory. The shear thinning effect is considered in setting up the mathematical model of the ultra thin film rheology. The Reynolds equation and the perturbation theory are employed to set up the static pressure distribution model and to deduce the dynamic pressure equation. The static and dynamic equations are solved by finite difference method. Based on the dynamic analysis the dynamic response of the slider is simulated and some valuable results are obtained about the static and dynamic characteristics of the liquid lubricated head disk systems.

Responses of Vegetation and Primary Production in North-South Transect of Eastern China to Global Change Under Land Use Constraint

A regional model of vegetation dynamics was revised to include land use as a constraint to vegetation dynamics and primary production processes. The model was applied to a forest transect in eastern China (NSTEC, North-South transect of eastern China) to investigate the responses of the transect to possible future climatic change. The simulation result indicated that land use has profound effects on vegetation transition and primary production. In particular, land use reduced competition among vegetation classes and tended to result in less evergreen broadleaf forests but more shrubs and grasses in the transect area. The simulation runs with land use constraint also gave much more realistic estimation about net primary productivity as well as responses of the productivity to future climatic change along the transect. The simulations for future climate scenarios projected by general circulation models (GCM) with doubled atmospheric CO2 concentration predicted that deciduous broadleaf forests would increase, but conifer forests, shrubs and grasses would decrease. The overall effects of doubling CO2 and climatic changes on NSTEC were to produce an increased net primary productivity (NPP) at equilibrium for all seven GCM scenarios. The predicted range of NPP variation in the north is much larger than that in the south.

Seize the long tail, traditional metamorphosis interconnection

the traditional enterprise transformation, thanks to the Internet is a hot topic in recent years, many companies are testing the waters, but the real success is not much. This article through to the kaiyuan long tail economy, crowdsourcing platform, C2B customization model and information system four aspects of the introduction and analysis, trying to traditional enterprise transformation of the Internet, to provide reference.

Dynamic Evolvement of Agricultural System and Typical Patterns of Modern Agriculture in Coastal China:A Case of Suzhou

Based on dynamic theory of system, agriculture is a complex system composed by element, structure, function and development. Firstly, this paper analyzes their connotation and relationship, which could be simply described that in virtue of element integrating and structure optimizing, agricultural system may achieve multifunctionality to meet increasingly diverse demands. As a case study of Suzhou, it concludes that Suzhou has a LP-dependence on agricultural element, and the growth extent of agricultural productivity correlates to the ratio of agricultural labor reduc- ing rate to farmland reducing rate. Agricultural structure of Suzhou changed with time, and in the early 1980s and 2000s it was most notable. Correspondingly, agricultural function has experienced a succession process: 'production', 'production-living', and 'production-living-ecology'. At last, based on questionnaires and interviews, some new characteristics and problems of agricultural development in coastal developed region of China have been put forward. Meanwhile, some typical patterns of modern agriculture in Suzhou which adapt to system evolving are also brought up such as export-oriented agriculture, enterprises-leading agriculture, agricultural science and technology parks, characteristic and stereoscopic agriculture, tourism and sightseeing agriculture.

How Well does BCC_CSM1.1 Reproduce the 20th Century Climate Change over China?

The historical simulation of phase five of the Coupled Model Intercomparison Project （CMIP5） ex- periments performed by the Beijing Climate Center cli- mate system model （BCC_CSM1.1） is evaluated regard- ing the time evolutions of the global and China mean sur- face air temperature （SAT） and surface climate change over China in recent decades. BCC CSM1.1 has better capability at reproducing the time evolutions of the global and China mean SAT than BCC_CSM1.0. By the year 2005, the BCC_CSM1.1 model simulates a warming am- plitude of approximately I℃ in China over the 1961- 1990 mean, which is consistent with observation. The distributions of the warming trend over China in the four seasons during 1958-2004 are basically reproduced by BCC CSM1.1, with the warmest occurring in winter. Al- though the cooling signal of Southwest China in spring is partly reproduced by BCC_CSM1.1, the cooling trend over central eastern China in summer is omitted by the model. For the precipitation change, BCC_CSM1.1 has good performance in spring, with drought in Southeast China. After removing the linear trend, the interannual correlation map between the model and the observation shows that the model has better capability at reproducing the summer SAT over China and spring precipitation over Southeast China.

Urokinase perfusion prevents intrahepatic ischemic-type biliary lesion in donor livers

AIM： To evaluate whether urokinase perfusion of non-heart-beating cadaveric donor livers reduces the incidence of intrahepatic ischemic-type biliary lesions （IITBLs）. METHODS： A prospective study was conducted to investigate potential microthrombosis in biliary microcirculation when non-heart-beating cadaveric livers were under warm or cold ischemic conditions. The experimental group included 140 patients who underwent liver transplantation during the period of January 2006 to December 2007, and survived for more than 1 year. The control group included 220 patients who received liver transplantation between July 1999 and December 2005 and survived for more than 1 year. In the experimental group, the arterial system of the donor liver was perfused twice with urokinase during cold perfusion and after trimming of the donor liver. The incidence of IITBLs was compared between the two groups. RESULTS： In the control group, the incidence of IITBLs was 5.9% （13/220 cases） after 3-11 mo of transplantation. In the experimental group, two recipients （1.4%） developed IITBLs at 3 and 6 mo after transplantation, respectively. The difference in the incidence between the two groups was statistically significant （P 〈 0.05）. CONCLUSION： Double from non-heart-beating perfusion of cadaveric livers donors with urokinase may reduce the incidence of IITBLs.

Prediction of representative deformation modulus of longwall panel roof rock strata using Mamdani fuzzy system

Deformation modulus is the important parameter in stability analysis of tunnels, dams and mining struc- tures. In this paper, two predictive models including Mamdani fuzzy system （MFS） and multivariable regression analysis （MVRA） were developed to predict deformation modulus based on data obtained from dilatometer tests carried out in Bakhtiary dam site and additional data collected from longwall coal mines. Models inputs were considered to be rock quality designation, overburden height, weathering, unconfined compressive strength, bedding inclination to core axis, joint roughness coefficient and fill thickness. To control the models performance, calculating indices such as root mean square error （RMSE）, variance account for （VAF） and determination coefficient （R^2） were used. The MFS results show the significant prediction accuracy along with high performance compared to MVRA results. Finally, the sensitivity analysis of MFS results shows that the most and the least effective parameters on deformation modulus are weatherin~ and overburden height, respectively.

Expressway Traffic Flow Model Study Based on Different Traffic Rules

In this paper, two cellular automata traffic models are proposed to simulate the operation of an expressway. The results show that the flow rate and the average velocity are generally equal in the same density which is different among the lanes. The analysis of lane changing times and the velocity total deviation show some characteristics which are difficult to explain phase transitions under fundamental diagram theory. Therefore,the concept of lane changing probability is introduced, and it is concluded that the speed-limit rule can reduce the motivation of lane changing effectively.

Analysis of the Mode of the Periodically Time-varying Vibration Systems

By Liapunov reducibility theorem, the periodically time-varying vibration system can be transformed to a linear time-invariant system. Based on the dynamic characteristics of the linear time-invariant system, the mode of the periodically time-varying vibration system has been discussed. The paper defines the mode and analyzes its characteristics. It can be found that the mode of the periodically time-varying system is periodically time-varing but has such characteristics as orthogonality. Finally, a method is given to solve the mode. By solving the eigenvalues and the eigenvectors of the state transition matrix in one period, the periodically time-varying mode can be obtained.

Lyapunov-Krasovskii functional based power system stability analysis in environment of WAMS

In order to analyze power system stability in environment of WAMS(wide area measurement system),a new steady state stability model with time-varying delay was proposed for power system.The factors of exciter and power system stabilizer with delay were introduced into analytical model.To decrease conservativeness of stability analysis,an improved Lyapunov-Krasovskii functional was constructed,and then a new delay-dependent steady state stability criterion for power system,which overcomes the disadvantages of eigenvalue computation method,was derived.The proposed model and criterion were tested on synchronous-machine infinite-bus power system.The test results demonstrate that Lyapunov-Krasovskii functional based power system stability analysis method is applicable and effective in the analysis of time delay power system stability.

Solitons with Periodic Behavior in Korteweg-de Vries Type Models Related toSchrodinger System

The linear variable separation approach is successfully extended to(1+1)-dimensional Korteweg-de Vries (KdV) type models related to Schrodinger system. Somesignificant types of solitons such as compaction, peakon, and loop solutions with periodic behaviorare simultaneously derived from the (l+l)-dimensional soliton system by entrancing appropriatepiecewise smooth functions and multivalued functions.

Simulating Hydrologic Changes with Climate Change Scenarios in the Haihe River Basin

Climate change scenarios, predicted using the regional climate modeling system of PRECIS (providing regional cli-mates for impacts studies), were used to derive three-layer variable infiltration capacity (VIC-3L) land surface model forthe simulation of hydrologic processes at a spatial resolution of 0.25° × 0.25° in the Haihe River Basin. Three climatescenarios were considered in this study: recent climate (1961-1990), future climate A2 (1991-2100) and future climateB2 (1991-2100) with A2 and B2 being two storylines of future emissions developed with the Intergovernmental Panel onClimate Change (IPCC) special report on emissions scenarios. Overall, under future climate scenarios A2 and B2, theHaihe River Basin would experience warmer climate with increased precipitation, evaporation and runoff production ascompared with recent climate, but would be still likely prone to water shortages in the period of 2031-2070. In addition,under future climate A2 and B2, an increase in runoff during the wet season was noticed, indicating a future rise in theflood occurrence possibility in the Haihe River Basin.

Lie-Form Invariance of a Type of Non-holonomic Singular Systems

In this paper, the Lie-form invariance of a type of non-holonomic singular systems is studied. The differential equations of motion of the systems are given. The definition and the criterions of the Lie-form invariance for the systems are presented. The Hojman conserved quantity and the Mei conserved quantity are obtained. An example is given to illustrate the application of the results.