双剪应力四参数和五参数准则

本文在作者1962年提出的普遍形式强度理论和1983年的广义双剪应力强度理论的基础上,进一步考虑材料强度性质在π平面和拉伸子午线及压缩子午线上的不同变化规律,得出了适用于描述岩土类材料破坏规律的双剪应力四参数准则和双剪应力五参数准则.其特例可适用于金属类材料.研究结果表明,近年来国内外提出的一些著名的强度理论和多参数准则可以作为本文结果的特例或逼近.     

Studies on Wear and corrosion resistances of carbon nitride thin films on Ti alloy

0　IntroductionArtificialarthrosiseshavebeenwidelyusedintheoperatorsclinicalsurgeriesforthepatientswhosearthrosiseswerese riouslyseverelydamaged.Butmostofartificialarthrosisescanon lybeusedforabouttenyearslongduetotheseriousabrasion .Forthisreason ,theimprovementofthelongevityofartificialarthrosisbecomesanimportantsubjectofstudy .TheartificialarthrosisesbeingmadeupofTialloyTC4(Ti 6Al 4V)andthepolythenewithultrahighmolecularweighthavegreatpotentialitiesonim provinglongevitybecauseTC4canreac…     

Optimizing Concurrent Product Development Process Using Genetic Algorithm

0　IntroductionTimesaving,timetomarketandcycletimereductionarethenewgoalsandaimsforenterprisesinordertosuccessfullycompeteintothemodernglobalmarket[1].Thereisnodoubtthatconcurrentconsiderationofproductandprocessdesignimprovesproductqualityandreducesthere-designwork,whichleadstoshorterproductlead-time.Buttheconcurrentdevelopmentfashionbringsaboutmoreobstaclessuchascomplextimeorder,informationandresourceconstrainednatureofrelationshipsbetweenactivitiestothedesignprocess,whichleadtothefactthatiti…     

A Novel Robust Adaptive Fuzzy Controller

For a class of continuous-time nonlinear system, a novel robust adaptive fuzzy controller is proposed by using of Lyapunov method. It is proven that the control algorithm is globally stable, the output tracking-error can convergence to a domain of zero under the assumptions. As a result, the system controlled has stronger robustness for disturbance and modeling error.     

The Beetles of Tribe Platyopini in China and Description of Two New Species(Coleoptera:Tenebrionidae)

ＴｈｅｔｒｉｂｅＰｌａｔｙｏｐｉｎｉｉｓａｐｅｃｕｌｉａｒｉｎｓｅｃｔｇｒｏｕｐ ,ｗｈｉｃｈｉｓｄｉｓｔｒｉｂｕｔｅｄｉｎＥａｓｔＡｓｉａ ,ＣｅｎｔｒａｌＡｓｉａａｎｄＮｏｒｔｈＡｆｒｉｃａ .Ｔｈｅｓｅｂｅｅｔｌｅｓａｒｅｔｙｐｉｃａｌｉｎｓｅｃｔｓｉｎｄｅｓｅｒｔ .Ｕｐｔｏｄａｔｅ ,35ｓｐｅｃｉｅｓｏｆ 11ｇｅｎｅｒａｈａｖｅｂｅｅｎｒｅｐｏｒｔｅｄａｌｌｏｖｅｒｔｈｅｗｏｒｌｄ ,ａｍｏｎｇｗｈｉｃｈ ,4ｓｐｅｃｉｅｓｏｆ 2 ｇｅｎｅｒａ (ａｂｏｕｔ 11.4 %ｏｆｔｈｅｔｏｔａｌ)ａｒｅｋｎｏｗｎｆ…     

Application of Splitting Extrapolation to Stokes Equation

0　ＩｎｔｒｏｄｕｃｔｉｏｎＴｈｅＳｔｏｋｅｓｅｑｕａｔｉｏｎｈａｓｗｉｄｅ ｒａｎｇｉｎｇｐｈｙｓｉｃａｌｂａｃｋｇｒｏｕｎｄｓ.Ｔｉｌｌｎｏｗ ,ＭａｎｙｐａｐｅｒｓｆｏｒｎｕｍｅｒｃｉａｌｓｏｌｕｔｉｏｎｓｏｆＳｔｏｋｅｓｅｑｕａｔｉｏｎｈａｖｅｂｅｅｎｐｒｅｓｅｎｔｅｄ .Ｂｒｅｚｚｉｅｔａｌ[1] ｈａｖｅａｌｒｅａｄｙｕｓｅｄｔｈｒｅｅｓｔａｂｌｉｚｅｄｍｉｘｅｄｍｅｔｈｏｄｓａｎｄｏｂｔａｉｎｅｄｔｈｅａｐｐｏｒｘｉｍａｔｅｓｏｌｕ ｔｉｏｎｏｆｔｈｅＳｔｏｋｅｓｅｑｕａｔｉｏｎａｎｄｔｈｅｅ…     

On Robust Stability of a Class of Uncertain Nonlinear Systems with Time—Varying Delay

The problem of robust stability of a class of uncertain nonlinear dynamical systems with time-delay is considered. Based on the assumption that the nominal system is stable, some sufficient conditions on robust stability of uncertain nonlinear dynamical systems with time-delay are derived. Some analytical methods and a type of Lyapunov functional are used to investigate such sufficient conditions. The results obtained in this paper are applicable to perturbed time-delay systems with unbounded time-varying delay. Some previous results are improved and a numerical example is given to demonstrate the validity of our results.     

南极环境对人体生理和心理健康的影响

介绍了甸南极考察队员在南极环境的影响下，机体生理、内分泌、免疫系统和心理活动的某些变化，上述观察对如何提高南极考察队员的适应能力以及从生理和心理方面选择队员提供了初步依据。     

A data model for regions with indeterminate boundaries

Most of spatial phenomena like natural vegetation units and land use areas constantly change over time and have uncertainty spatial extents. Till now, a considerable number of data models have been proposed for spatial objects with sharp boundaries as well as with indeterminate boundaries. However, they mainly concern space and time or space and fuzziness and not yet integrate them into a single unified framework. This paper introduces a formal definition of the conceptual fuzzy spatiotemporal data model, called FSTDM for fuzzy regions based on fuzzy set theory. We also contribute a method of manipulating queries with the presence of both temporal predicate and fuzzy spatial predicate in the condition clause efficiently. We then implement a prototype system. Through the experimental results, we prove that our work can be used to build a specialized system such as GIS, spatial database, and so on.