对一道涉及密度的溶液配比问题的探讨     

余海涛 《黄冈职业技术学院学报》1999,(4)

分析解答了一道涉及密度的溶液配比的问题,通过讨论得出此类问题的一般结论.  相似文献   

SH3603汽车驱动桥齿轮联接螺栓断裂原因及消除方法     

韩进  刘朝红  陈善忠 《辽宁科技学院学报》1999,(2)

对SH3603（35D）型矿用汽车驱动桥主减速器一、二级从动齿轮的联接螺栓断裂事故进行了疲劳断裂理论分析,找出了根本原因,并提出具体的消除方法。  相似文献   

两类聚苯胺复合基体手性材料吸波性能的研究   总被引：3，自引：0，他引：3  

章平  王国强  谢红 《郧阳师范高等专科学校学报》1999,(3)

我们制备了MnZn铁氧体聚苯胺复合基体和Fe3O4聚苯胺复合基体的碳纤维手性材料,利用微波国波导法在8．5－11．0GHz频宽内测量了各手性材料的电磁参量,计算出自由空间中的短路反射系数。对短路反射系数受频率、基体中铁氧体浓度的影响作了分析。  相似文献   

土壤和建筑材料表面氡析出率对室内氡浓度的影响     

贺小凤  王国胜  符适 《深圳信息职业技术学院学报》2011,(3):62-67

采用监测数据可靠的RAD7测氡仪,选择深圳市某平房为研究对象,检测到平房周围为土壤氡低背景区,且土壤表面氡析出率较大,约为房间内水泥地板的2倍,说明土壤是室内氡的最大来源;而水泥地板表面氡析出率较瓷砖地板大,约为瓷砖地板的4倍。铺有水泥地板的房间室内氡浓度大于铺有瓷砖地板的房间,这是由于水泥地板表面氡析出率较大。因此,为了减少室内氡浓度,应该尽可能选择表面氡析出率低的材料铺设地板,并保持开窗通风。  相似文献   

Metal-organic frameworks enable broad strategies for lithium-sulfur batteries     

Cheng Zhou  Zhaohuai Li  Xu Xu  Liqiang Mai 《国家科学评论(英文版)》2021,8(12)

The lithium-sulfur (Li-S) battery is considered to be a potential next-generation power battery system, however, it is urgent that suitable materials are found in order to solve a series of challenges, such as the shuttle effect and lithium dendrite growth. As a multifunctional porous material, metal-organic frameworks (MOFs) can be used in different parts of Li-S batteries. In recent years, the application of MOFs in Li-S batteries has been developed rapidly. This review summarizes the milestone works and recent advances of MOFs in various aspects of Li-S batteries, including cathode, separator and electrolyte. The factors affecting the performance of MOFs and the working mechanisms of MOFs in these different parts are also discussed in detail. Finally, the opportunities and challenges for the application of MOFs in Li-S batteries are proposed. We also put forward feasible solutions to related problems. This review will provide better guidance for the rational design of novel MOF-based materials for Li-S batteries.  相似文献   

谈国库集中支付制度的积极意义     

武俊英  程咏秀 《安阳工学院学报》2005,(6):98-99

国库集中支付制度是市场经济国家普遍实行的现代国库管理制度.实行国库集中支付制度,有利于健全财政监督机制,有利于政府加强资金的统一调度和管理,有利于规范预算单位的财政收支行为.  相似文献   

大气颗粒物浓度检测技术及其发展   总被引：8，自引：0，他引：8  

杨书申  邵龙义  龚铁强  刘昌凤 《北京工业职业技术学院学报》2005,4(1):36-39

大气颗粒物是一种重要的空气污染物,详细分析了大气颗粒物浓度的检测原理、检测方法.基于膜捕集的称重法是最基本的颗粒物浓度检测方法,但是基于其他原理的颗粒物浓度检测方法在颗粒物的实时在线检测方面得到了广泛应用,对各类监测方法的优缺点作了对比,指出自动化、智能化和网络化是大气颗粒物浓度检测仪器的方向发展.  相似文献   

行政事业单位会计集中核算的问题、对策及发展方向   总被引：2，自引：0，他引：2  

王波 《山东商业职业技术学院学报》2009,9(2):23-25,29

近年来,行政事业单位的财政会计制度、资金拨付方式的改革在全国100多个城市展开,有的实行会计集中核算制度,有的实行国库集中支付制度。2004年济南市政府为了进一步转变政府职能,加强对财政资金使用的监督,实行了行政事业单位的会计集中核算制度。从会计集中核算的特点、推行集中核算的意义等几个方面进行探讨,认为会计集中核算制度如能与国库集中支付制度相结合,则既能节约管理成本,又能同时解决资金拨付过程中闲置浪费的问题。  相似文献   

商业银行信贷集中衡量指标体系补充设计     

颜廷峰 《哈尔滨学院学报》2010,31(4):44-51

文章根据现代投资组合理论与投资风险管理方法对信贷集中衡量指标体系进行了补充设计。在宏观层面上按贷款投放的产业类别、行业和地区补充了17个指标,在微观层面上增加了对一二级分行考核的11个指标。补充设计后的指标体系由现行的3个指标完善为31个指标,提高了指标体系的层次性和适用性。  相似文献   

Computational fluid dynamics simulation of formaldehyde emission characteristics and its experimental validation in environment chamber   总被引：1，自引：0，他引：1  

LIU Zhi-jian  LI An-gui  WANG Zhi-chao  DENG Gao-feng 《重庆大学学报(英文版)》2010,9(3):124-132

We investigated the effect of supply air rate and temperature on formaldehyde emission characteristics in an environment chamber. A three-dimensional computational fluid dynamics （CFD） chamber model for simulating formaldehyde emission in twelve different cases was developed for obtaining formaldehyde concentration by the area-weighted average method. Laboratory experiments were conducted in an environment chamber to validate the simulation results of twelve different cases and the formaldehyde concentration was measured by continuous sampling. The results show that there was good agreement between the model prediction and the experimental values within 4.3% difference for each case. The CFD simulation results varied in the range from 0.21 mg/m3 to 0.94 mg/m3, and the measuring results in the range from 0.17 mg/m3 to 0.87 mg/m3. The variation trend of formaldehyde concentration with supply air rate and temperature variation for CFD simulation and experiment measuring was consistent. With the existence of steady formaldehyde emission sources, formaldehyde concentration generally increased with the increase of temperature, and it decreased with the increase of air supply rate. We also provided some reasonable suggestions to reduce formaldehyde concentration and to improve indoor air quality for newly decorated rooms.  相似文献