聚焦中国的节能减排

中国节能减排要解决大气污染的3个问题：一是传统生物质能利用造成的室内和地区环境污染;二是化石能源利用造成的二氧化碳、氮氧化物和烟尘污染;三是二氧化碳排放造成的全球气候变暖。鉴于中国能源状况的特殊性,中国既要解决传统生物质能的节约和替代问题,也要解决化石能源利用的节约和减排问题。但中国节能减排的首要问题是要解决化石能源造成的地区污染问题。     

PFI汽油机整车冷启动失火问题研究

PFI汽油机整车冷启动失火问题是汽车主要"冬季病"之一,会造成发动机抖动、OBD故障灯点亮、排放超标等问题。本文分析了冷启动失火问题的可能原因,结合典型案例的排查过程,说明了该问题在研发、生产、使用等环节都有可能造成风险的隐患,为规避该问题指出了可能方向。     

3~#TRT系统联络柜相间涡流处理及改造

针对3#TRT系统联络柜在运行过程中发现的触头发热问题,分析涡流损耗是造成触头发热的原因,并提出防止涡流发热的对策。通过采取措施,处理了系统联络柜出厂时的缺陷,解决了涡流造成触头发热问题。     

内燃机车轮箍红外测温装置的研制与运用

对内燃机车轮箍弛缓造成牵引动力无法正常输出的问题进行分析,找出造成轮箍弛缓的直接原因系轮箍运行温度高造成。从监控预防角度出发,开发基于PLC的红外测温装置,实时在线监控轮箍运行温度,提醒乘务员采取有效措施,提高机车运行效率。     

浅析发动机漏气量影响因素

发动机漏气量问题一直是主机厂和零部件厂经常遇到的问题,漏气量大会造成发动机的功率下降,还会造成发动机润滑油劣化变质结焦积碳,活塞环卡死、拉缸等更严重的问题.本文试在探讨一下发动机的漏气量影响因素及解决方法.     

《用行动减少塑料袋的使用》

目前被普遍使用的一次性塑料购物袋的滥用所造成的白色污染等环境问题已经成为城市日益严重的问题。据测算，北京目前的塑料袋年消费量已近100亿只。这些塑料袋对环境造成很大压力，不仅对市容、景观造成破坏，更重要的是，大部分废塑料制品进入自然环境后难以降解，会带来长期的深层次环境问题．造成农作物减产、动物死亡，焚烧时产生有毒的烟尘等。     

解析我国矿产资源管理

论述我国现行矿产资源管理制度存在的主要问题,分析造成问题的主要原因并提出解决的办法。     

一种并联SiC MOSFETs的静态均流方法

在光伏发电或风力发电等大电流应用场合,由于并联SiC MOSFETs功率源极寄生电感和漏极寄生电感的不匹配会导致静态电流的不平衡,该文提出一种用于并联SiC MOSFETs静态均流的方法。该文首先分析并解决因阈值电压不匹配造成的动态不平衡电流问题,然后在其基础上解决源极寄生电感不匹配造成的动态不平衡电流问题,最后在无阈值电压不匹配和源极寄生电感不匹配造成的动态不平衡电流的基础上解决漏极寄生电感不匹配造成的静态不平衡电流问题。最终,通过实验验证了该文所提出的静态均流方法的有效性。     

迈能高科:“26万次”树立行业新标杆

我国太阳能热利用产业经过近三十年的发展,太阳能热水器总保有量占世界总量的70%,已经成为世界第一生产和使用大国。但多年来,行业突破性技术难见,产品价格战造成的质量问题一直困扰着企业和用户,而由于产品质量问题造成的产品报废率以及浪费现象更是触目惊心。中国     

660MW超超临界锅炉再热蒸汽欠温分析与处理方案

国内火电机组引进的660MW超超临界锅炉技术,锅炉整体运行效果良好。但近几年,部分660MW超超临界电厂反馈存在再热蒸汽欠温问题,再热蒸汽汽温达不到额定值,低负荷工况下该问题更为明显,造成锅炉及机组效率偏低,对电厂的经济效益造成极大影响。     

BODY-FORCE ANALOGY FOR ONE-DIMENSIONAL COUPLED DYNAMIC PROBLEMS OF THERMOELASTICITY

ABSTRACT

The classical body-force analogy for static problems of thermoelasticity is extended toward dynamic coupled problems. We consider two dynamic problems, namely, a thermal problem without body forces, but with a given distribution of transient sources of heat, and a force problem without sources of heat but with body forces. Both problems are treated within the coupled theory of thermoelasticity such that temperature must also be taken into account in the force problem. We restrict our considerations to the one-dimensional case, and we show that, given suitable boundary and initial conditions, a distribution of body forces can be constructed such that the dynamic displacements in both problems become equal. This analogy is checked by means of illustrative analytical examples. We also discuss the relations between the stresses and the temperature in both problems, and we mention that a similar analogy can be established, requiring the temperatures in both problems to be equal.     

生物质灰熔融粘结问题分析

对生物质直接燃烧过程中的灰熔融粘结问题进行了总结,分析了生物质直接燃烧过程中生物质灰分熔融粘结的预测方法、解决途径,为生物质灰熔融粘结问题的进一步解决提供技术参考。     

常压热水锅炉及其供暖系统技术问题

提出了常压锅炉的一些水循环问题及供暖系统中一些部位负压等问题 ,找到了解决这此问题的方法     

The UNIT algorithm for solving one-dimensional convection-diffusion problems via integral transforms

A unified approach for solving convection-diffusion problems using the Generalized Integral Transform Technique (GITT) was advanced and coined as the UNIT (UNified Integral Transforms) algorithm, as implied by the acronym. The unified manner through which problems are tackled in the UNIT framework allows users that are less familiar with the GITT to employ the technique for solving a variety of partial-differential problems. This paper consolidates this approach in solving general transient one-dimensional problems. Different integration alternatives for calculating coefficients arising from integral transformation are discussed. Besides presenting the proposed algorithm, aspects related to computational implementation are also explored. Finally, benchmark results of different types of problems are calculated with a UNIT-based implementation and compared with previously obtained results.     

充填采矿技术在煤炭开采中的应用

中国煤矿多是地下开采,开采过后很容易引发环境问题。随着经济的发展,社会各界对环境保护的要求越来越高。因此,必须要采取科学、合理的方式来解决煤矿开采引发的环境问题,充填采矿技术就是为了解决这种问题而产生的。简要阐述了煤矿开采中引发的环境问题,然后分析了充填采矿技术的基本原理以及优势,最后探讨了充填采矿技术的应用情况,以期为日后相关工作的开展提供借鉴。     

煤矿机电设备存在的问题及变频技术的应用

煤矿生产的机械化使得生产的效率和安全性大幅度提高,但传统的煤矿机电设备在运行时还存在着各种问题,严重制约了煤矿生产效率的进一步提高。因此,有必要从根本上解决这些机电设备运行中的问题,从而实现生产的高产高效。分析了煤矿机电设备运行过程中存在的问题,并将变频技术引入机电设备控制中来解决这些问题,可以为煤矿生产的现代化提供一定的参考。     

Applying the Hopfield Neural Network to the Solution of the Temperature Distribution Field in Heat Conduction Problems

This article employs the continuous-time analog Hopfield neural network (CHNN) to compute the temperature distribution in one- and two-dimensional transient heat conduction problems. The relationship between the CHNN synaptic connection weights and the governing equations of the problems is established and a corresponding network connectivity circuit design scheme proposed. The CHNN algorithm is initially applied to the solution of conventional problems and is then used to solve more complicated problems involving time-varying heat flux profiles. The results confirm that the CHNN scheme provides an accurate means of solving the transient temperature distributions of heat conduction problems on a real-time basis.     

Solving transient heat conduction problems on uniform and non-uniform lattices using the lattice Boltzmann method

The lattice Boltzmann method (LBM) has been used to solve transient heat conduction problems in 1-D, 2-D and 3-D Cartesian geometries with uniform and non-uniform lattices. To study the suitability of the LBM, the problems have also been solved using the finite difference method (FDM). To check the performance of LBM for the non-uniform lattices, the results have been compared with uniform lattices. Cases with volumetric heat generation have also been considered. In 1-D problems, the FDM with implicit scheme was found to take more number of iterations and also the CPU time was more. However, with explicit scheme, with increase in the number of control volumes, the LBM was found faster than the FDM. In 2-D and 3-D problems, with increase in the number of control volumes, the LBM was found faster than the FDM. In 2-D problems, number of iterations in the two methods was comparable, while in 3-D problems, the LBM was found to take less number of iterations. The accurate results were found in all the cases.     

Heterogeneous Heat Conduction Problems by an Improved Element-Free Galerkin Method

In this article an improved element-free Galerkin method is proposed to solve heat conduction problems with heterogeneous media. Because the method almost possesses interpolation property, the implementation of essential boundary condition is as simple as that in the finite-element method. In order to validate the proposed method, several heat conduction problems with different degrees of heterogeneity are presented. In these test problems, we focus on the influence of nodal distribution to the proposed method for heat conduction problems with heterogeneous media. It is shown that, for different degrees of heterogeneity, regardless of matter whether the node is located on the interface, accurate solutions can be obtained by the proposed method for heterogeneous heat conduction problems without a source term.     

汽车维修行业存在的问题分析及有关建议

通过剖析汽车维修行业存在的三个方面的问题,提出了解决问题的具体措施。