钢-砼组合梁负弯矩区抗弯承载力的计算建议

钢-混凝土组合梁具有一系列的优点,在工程实践中的应用也日益广泛,因此,关于此类构件抗弯承载力的设计方法就显得尤为重要.笔者分析了传统设计方法和规程设计方法,发现对于承受负弯矩的钢-混凝土组合梁,当截面塑性中和轴位于钢梁上翼缘时,传统方法过于保守,规程方法的个别计算式不正确;应用等效应力法提出了新的计算建议,以算例对3种方法进行了对比,并通过试验研究加以验证,结果表明,本文的计算建议最能反映实际情况,能够保证计算的合理性.

绿色医疗与医院感染防控

绿色医疗和医院感染预防与控制都是医疗安全的重要保障,改善就诊环境,保障清洁的医疗和畅通的医疗服务流程,减少病人在医院内的感染风险,减少医源性感染和伤害,以保障医患安全,是医院感染管理和绿色医疗的重要内容和要求。本文就医院感染预防与控制和绿色医疗的关系,以及做好医院感染的预防与控制应该关注和改进的九个方面问题,进行了详细的论述,从而达到实现绿色医疗要求,确保医疗过程的安全的目的。

The Design of Water-reusing Network with a Hybrid Structure Through Mathematical Programming

A new design method for a water-reusing network, with a hybrid structure, to reduce the complexity of the network and to minimize freshwater consumption, is proposed. The unique feature of the methodology proposed .in this article is to control the complexity of the water network by regulation of the control number in a water-reusing system. It combines the advantages of a conventional water-reusing network and a water-reusing net work with internal water mains. To illustrate the proposed method, a single contaminant system and a multiple contaminant system serve as examples of the problems.

计量器具在环境安全监测中的应用

随着我国经济总量的不断扩大,人民物质生活水平的日益提高,人们对周围的生存环境越来越关注。本文探讨了计量是单位统一、量值准确可靠的活动,阐述了计量是环境安全监测的有力工具。统一性是计量的本质,准确性是计量的核心。环境安全监测结果的有效性与计量器具、环境标准物质、标准和方法密不可分。

Research of inverse mathematical model to high-speed trains

Operation safety and stability of the train mainly depend on the interaction between the wheel and rail.Knowledge of wheel/rail contact force is important for vehicle control systems that aim to enhance vehicle stability and passenger safety.Since wheel/rail contact forces of high-speed train are very difficult to measure directly,a new estimation process for wheel/rail contact forces was introduced in this work.Based on the state space equation,dynamic programming methods and the Bellman principle of optimality,the main theoretical derivation of the inversion mathematical model was given.The new method overcomes the weakness of large fluctuations which exist in current inverse techniques.High-speed vehicle was chosen as the research object,accelerations of axle box as input conditions,10 degrees of freedom vertical vibration model and 17 degrees of freedom lateral vibration model were established,respectively.Under 250 km/h,the vertical and lateral wheel/rail forces were identified.From the time domain and frequency domain,the comparison of the results between inverse and SIMPACK models were given.The results show that the inverse mathematical model has high precision for inversing the wheel/rail contact forces of an operation high-speed vehicle.

New Multiple Soliton-like and Periodic Solutions for （2＋l）-Dimensional Canonical Generalized KP Equation with Variable Coefficients

In this paper, the generalized ranch function method is extended to （2＋1）-dimensianal canonical generalized KP （CGKP） equation with variable coetfficients. Taking advantage of the Riccati equation, many explicit exact solutions, which contain multiple soliton-like and periodic solutions, are obtained for the （2＋1）-dimensional OGKP equation with variable coetffcients.

从不同版本LATBSDC规范修订看美国性能化设计思路变化

LATBSDC规范是洛杉矶高层建筑设计委员会推出的一本基于性能化设计原则的高层设计规范。LATBSDC规范推出后经历了多个版本的修编,反映了美国性能化设计思路的变化。对比了不同版本LATBSDC规范对性能目标、材料强度与刚度取值、地震输入、阻尼比、最小底部剪力、偶然偏心和扭转位移比、位移限值等方面规定的修订以及与我国规范的异同,以供今后在性能化设计和规范修订中参考。通过对比分析发现我国规范三水准两阶段设计方法具有一定的合理性;在充分采用大震弹塑性动力分析手段验证结构大震性能的情况下,可适当减弱小震弹性分析中的整体性指标的控制;建议我国对于弹塑性动力分析中材料强度取值、初始刚度取值、是否考虑偶然偏心、是否区分峰值弹塑性层间位移角和残余弹塑性层间位移角作出更明确规定;建议更广泛采用地震安全性评估方法确定不同重现期地震输入;建议重新评估高层建筑阻尼比的合理取值方式;建议适当放松正常使用极限状态下的弹性层间位移角限值。

Teaching method for reading views by analyzing lines and planes

This paper deals with the teaching method in reading engineering drawing. It introduces the basic theory and fundamental ideas as well as the approach of reading views by analyzing lines and planes. It gives out the steps for completing the third view based on the other two views. As it is easy and quick for students to read and understand views by this method, it is welcome by students in teaching practice.

Application of Snapback Chronometry Method in Calculation of Regulation

Work study is an area of construction production rationalization in which with scientific, logical, holistic and system analysis methods of the process we gain optimum in way of work and time of work. Chronometry method is one of the work study methods which is appropriate for recording shorter cyclic processes and is based on statistical sampling theory. Determination of cyclic times and work performances of standard cyclic construction machines （SCCM） is one of key assumptions of dynamic planning of machine work on every construction site. Calculation methods of SCCM work performances arc one of basic research objects in the field of construction organization and technology. Study shows applied chronometry method in work of standard cyclic construction machine. Goal of this study is to accomplish regulation through measured time cycle and compare measured effects with effects obtained with standard methodology of calculating hydraulic excavator practical achievement for gaining regulation in order to determine main reasons which effect work performance on site.

Constraints in Lean Optimization Method Tested on a Real Engineering Problem

Optimizing a vehicle includes testing millions of parameters with hundreds of constraints of the performance. In this article, 162 parameters are optimized with 5 constraints using Lean Optimization combined with Linear Programming. The method converges in this example in about 100 evaluations. This is less than the gradient method needs for its first step.

Iteration Linear Programming Method and Livestock Ration Optimization

Iterative linear programming methods are proposed for optimum balanced animal diet in this paper. According to ＂wooden bucket theory＂ of the nutritional balance, each nutrient in the feeding standard has equal importance. It＇s unreasonable to use common goal programming to attach different weighted value to different nutritional parameters. This paper introduces an effective algorithm to deal with this kind of problem. When the permitting cost of livestock ration is given, we can design a ration formula with linear program-this is the first round. Then, according to the differences between the permitting cost and the formula cost gained in the first round, adjust the feeding standard and the feeding raw materials, and conduct the second round of linear programming for ration formula. If there is still a very big difference between the formula cost and the permitting cost, the third round will be taken, and so on. In this iteration course the formula cost gradually approaches the permitting cost. It is the key that the feeding standard and feeding raw materials are modified in each round. This method ensured the nutritive equilibrium with the formulation of least-cost ration. This is an especially important method when the primary goal of the optimization tool is to improve economic and nutritive efficiency.

Buffer Sizing Method for Constructing Stable Schedules with Duration Constraints

The assumption of static and deterministic conditions is common in the practice of construction project planning. However, at the construction phase, projects are subject to uncertainty. This may lead to serious schedule disruptions and, as a consequence, serious revisions oft.he schedule baseline. The aim of the paper is developing a method for constructing robust project schedules with a proactive procedure. Robust project scheduling allows for constructing stable schedules with time buffers introduced to cope with multiple disruptions during project execution. The method proposed by the authors, based on Monte Carlo simulation technique and mathematical programming for buffer sizing optimization, was applied to scheduling an example project. The results were compared, in terms of schedule stability, to those of the float factor heuristic procedttre.

Try to talk about the education rules in the sport education and its value

physical education plays more and more important role in modern education, which can improve the students＇ physical fitness, it makes the students＇ comprehensive development, and it is indispensable in modern quality education courses. Concept in education rules is a product of modern economic society for the field of education reform, and it has come into being a kind of teaching method which is to keep up with the trend of The Times development. Education rules is the inheritance of traditional teaching method, it is also a reaction to the social development and changes, in this paper, and we will start from the main content and the education significance of rules education, and combine the current situation of physical education in colleges, as to carry on the detailed narration that it＇ s about education rules during the curriculum development. Discussing the rules of education in physical education curriculum, it hopes to be able to improve the efficiency of physical education curriculum, improve the quality of physical education teaching, and play a positive role in promoting for the development of physical education.

Anisotropic mesh generation methods based on ACVT and natural metric for anisotropic elliptic equation

Anisotropic meshes are known to be well-suited for problems which exhibit anisotropic solution features. Defining an appropriate metric tensor and designing an efficient algorithm for anisotropic mesh gen- eration are two important aspects of the anisotropic mesh methodology. In this paper, we are concerned with the natural metric tensor for use in anisotropic mesh generation for anisotropic elliptic problems. We provide an algorithm to generate anisotropic meshes under the given metric tensor. We show that the inverse of the anisotropic diffusion matrix of the anisotropic elliptic problem is a natural metric tensor for the anisotropic mesh generation in three aspects： better discrete algebraic systems, more accurate finite element solution and superconvergence on the mesh nodes. Various numerical examples demonstrating the effectiveness are presented.

Reproducibility in Surface-Enhanced Raman Spectroscopy

Surface-enhanced Raman spectroscopy（SERS） is an intense ongoing hot topic because it is an attractive tool for sensing or detecting molecules in trace amounts. Despite its high specificity and sensitivity, the SERS technique has not been established as a routine analytic method most likely due to the low reproducibility of the SERS signal. This review considers the influence factors to produce the poor reproducibility during the SERS measurement. This review starts with the discussion of calculation of surface-enhanced Raman intensity in order to explain the reason why it is so difficult to achieve a high reproducibility of SERS measurement from the origin of enhancement mechanism. Then we focus on the fabrication of SERS substrates generally including two types：① single particles and ② arrays on substrate that are directly used to detect molecules or other components.In addition, we discuss the molecule factors and optical system for the reproducibility for sample-to-sample or spot-to-spot on a substrate. In the final part of this review, some effects resulting in the irreproducibility of Raman bands＇ position from recent literatures are discussed.

Qualitative Analysis and Explicit Exact Solitary,Kink and Anti-Kink Wave Solutions of the Generalized Nonlinear Schrdinger Equation with Parabolic Law Nonlinearity

The generalized nonlinear Schrdinger equation with parabolic law nonlinearity is studied by using the factorization technique and the method of dynamical systems.From a dynamic point of view,the existence of smooth solitary wave,kink and anti-kink wave is proved and the sufficient conditions to guarantee the existence of the above solutions in different regions of the parametric space are given.Also,all possible explicit exact parametric representations of the waves are presented.