Strengthening of Emission Controlling for Small and Medium Sized Motorcycle Engine

It is very difficult for small and medium sized motorcycle engine to use the combination of closed-loop control electronic fuel injection system and three-way catalytic converter for emission controlling due to the high cost. In order to strengthen emission controlling of the carburetor motorcycle engines, the metering characteristics of carburetor are adjusted, combustion chamber as well as intake and exhaust ducts are further optimized, and secondary air injection system and oxidation type catalytic converter are developed, and moreover a simplified positive crankcase ventilator is employed to eliminate the gas blowby from crankcase. It is verified by test cycle testing that pollutant emissions of the carburetor motorcycle engines can be effectively controlled within the emissions limits by taking the above technical approaches.     

Technological Measures for Reducing Two-Stroke Motorcycle Exhaust Emissions

The main technological measures for reducing two stroke motorcycle exhaust emission in China and foreign country are introduced. The characteristics of the measures in structure, effect, cost, etc., are analysed. The results show that the enleanment of conventional carburetor mixture and the improvement of the carburetor intake passage shape is a simple and effective measure, the adoption of the electronically controlled in cylinder direct fuel injection technique is a unique measure to completely improve emissions from two stroke motorcycles. The structure and cost of a stratified scavenging system is lower than that of in cylinder direct fuel injection, but its effect is better than that of the enleanment of carburetor mixture, so, it is worth investigating further. The factories of two stroke motorcycles may select the reduction measures of the exhaust emission by referring to the analyses and comparisons.     

插电式混合动力汽车能量管理策略研究现状和发展趋势

目前国内外学者对插电式混合动力汽车能量管理策略进行了较为广泛和深入的研究,取得了良好的节能减排效果,为进一步提升其性能,有必要对插电式混合动力汽车能量管理策略的研究现状进行总结并对其发展趋势进行分析。首先对插电式混合动力汽车动力源能量流分配方法进行了归纳和分析,指出了当前插电式混合动力汽车能量管理策略两个亟待解决的问题：未考虑发动机冷却液温度和三元催化器温度等温度因素对油耗和排放影响;当前插电式混合动力汽车能量管理策略是以行驶功率需求作为输入,忽略了驾驶室制冷/供暖功率需求。最后提出了计及发动机冷却液温度和三元催化器温度等温度因素的能量管理策略和计及驾驶室制冷/供暖功率需求的能量管理策略两个未来研究方向。     

Current Situation and Prospects of Atrium Smoke Management Research

This paper surveys the current situation of atrium smoke management research at home and abroad. Recent research such as the types and configurations of atrium buildings, atrium smoke management system, smoke exhaust system modes and smoke exhaust effectiveness, atrium smoke filling process and its time constant, pre_stratification and detection, air flow for smoke control between the atrium and adjoining space, sprinkler effect are discussed. Regulations of atrium design and some problems in current national code (Code for Fire Protection Design of Tall Buildings GB50045-95) are also discussed and areas of further research are specified.     

Assessment and Suggestion on Management System of Vehicle Exhaust

This paper analyzes the deep reasons why the benefits are always poor though China has controlled the vehicle exhaust for more than ten years, as well as a successful experience of the developed countries. Contrasting the deficiencies of the previous Air Pollution Control Law and advantages of the present Air Pollution Control Law , the paper indicates the organization structure and management system of the EPA are not entirely eligible for the tasks though the new law entitles environmental administrations to strengthening the exhaust control. It calls for that, according to principle that a structure results in a function, China must establish the management system of vehicle emission control in metropolises as soon as possible. So we can implement this law and improve urban air quality that has deteriorated due to vehicle exhaust. This paper puts forward organization form, functions, tasks and effect of this system.     

基于三螺旋理论的农作物秸秆板产业化路径研究

中国农作物秸秆资源丰富, 以秸秆为原料的秸秆人造板作为新兴环保型产业, 其产业化具有重要现实意义, 因能有效解决秸秆露天焚烧引起的资源浪费与环境污染问题, 以及缓解木材供需矛盾而受到各方关注与重视。研究从中国农作物秸秆板产业化发展的现状出发, 通过对秸秆板产业化的支撑条件与不利因素分析, 以三螺旋理论为基础, 针对农作物秸秆板产业化过程中存在的若干问题, 从政府、 企业与科研机构 3个角度提出中国农作物秸秆人造板的发展路径。研究表明： 农作物秸秆板产业化的快速发展依赖于企业、 政府、 科研机构在发挥各自优势的基础上相互协作, 汇聚融合资金、 政策与人才优势来共同搭建创新协同平台, 集各方所长攻关难题瓶颈。     

农村学校“阳光体育”救济制度的研究进展

为了引入“阳光体育”救济制度确保农村学校阳光体育活动正常开展。结合农村学校“阳光体育”救济制度的内涵,在分析现阶段农村学校“阳光体育”活动现状的基础上,提出农村学校“阳光体育”救济制度的必要性,以及其遵循的基本原则,以期进一步完善农村学校“阳光体育”救济制度,为中国阳光体育蓬勃发展提供有益的参考。     

Main Influences of Credit and Loan Adjustment Policy on the Real Estate Enterprises and Their Countermeasures

In conjunction with the current situation of the real estate market in China, the main influence caused by the credit and loan adjustment policy is analyzed. On this basis, it has proposed some suggestions on how to strengthen the competitiveness and ability to resist risk of the real estate enterprise. At the end, it is emphasized, that the credit and loan adjustment policy not only makes the enterprise under enormous pressure, but provides a great opportunity of reducing rivals and expanding its own scale to those really powerful real estate enterprises. The real estate enterprise should seize this opportunity to meet the challenge to expand and strengthen itself.     

改进二次型Boost变换器的研究与分析

传统二次型Boost变换器具有较高的升压能力,但其开关器件的电压、电流应力较大,增加了电路的体积与成本。笔者在传统二次型Boost变换器的基础上,结合高增益Boost三端网络,提出改进二次型Boost变换器,并对其连续工作模式下的工作原理及各开关器件的电压、电流应力进行了分析。分析结果表明,改进二次型Boost变换器不仅升压能力有所提升,而且在输出电压相同的情况下,开关器件的电压、电流应力有所降低。最后,通过仿真分析验证了该变换器的正确性和可行性。     

中国秸秆资源“5F”利用方式的效益对比探析

参考文献： [1] 聂影,杨红强,苏世伟.中国原木进口国别结构与木材资源安全[J].林业经济,2008.3 [2] 沈文星,周定国.秸秆人造板的产业化问题[J] .林业科学,2007.3 [3] 吴树栋.中国农作物秸秆综合利用现状[J].人造板通讯,2005(8) [4] Volker E. Stockmann. Strawboard As An Emerging M aterial-PartⅠ:Historic perspectives and Global Opportunities. Pr occeedings of Symposium on utilization of agricultural and forestry residues.2001,Nanjing,50~59 [5] Dingguo Zhou. The development of Utilizing Agricultural Straws in China. Proceedings of Symposium on utilization of agricultural and forestry residues. 2001.Nanjing,1-11 [6] 张晓文,赵改宾,杨仁全,王影.农作物秸秆在循环经济中的综合利用[J].农业工程学报,2006(10) [7] 于文吉.生物质资源农作物秸秆应用于人造板工业的可行性分析[J].木材工业,2006(2) [8] 周定国,张洋.我国农作物秸秆材料产业的形成与发展[J].木材工业,2007.1     

CNKI期刊视域下降解地膜研究态势文献计量分析

以CNKI《中国学术期刊网络出版总库》为检索源,利用文献计量学方法,分析1987—2018年国内降解地膜研究态势。结果显示：降解地膜研究文献数量偏少,近10年来其速度和数量呈上升趋势;研究区域全国各地区均有涉及,新疆、甘肃、山东是研究靠前的3个地区;研究情报源分布较为广泛,但高质量载文期刊较少;研究人员分散不稳定,核心作者不突出;科研和教学单位是主要研究机构,研究内容多为应用降解地膜后对土壤水热及作物产量的影响,而在降解机理、环境安全方面的研究比较缺乏。建议降解地膜今后的研究方向和趋势应满足"五性一配套"综合体系,即：功能性、操作性、可控性、经济性、安全性和配套性。     

番石榴果实的营养价值和药理作用及其加工利用

综述番石榴的营养成分、药理作用、临床应用及其在食品工业中的开发利用现状,以及发展前景。青梅含有丰富的营养物质,具有降血糖、收敛止泻、止痒、抗氧化、平衡血糖及清肝、治疗糖尿病等功效,在医药和食品工业中有着广泛的作用。     

Displacement Prediction of Surrounding Rock by Evolution BP-net Based on the decimal Gentic Algorithms

In recent years,more people have begun complaining about cooking exhaust pollution from restaurants in the city of Chongqing,P.R.China.Understanding cooking exhaust pollution origins and people's responses in Chongqing can provide a scientific basis for environmental protection decision-making in the city.To better understand these things,the attitudes of Chongqing inhabitants with different sex,age and residential proximity to cooking exhaust pollution and other environmental pollutants were investigated.The results show that city residents feel cooking exhaust pollution is the third most significant environmental pollution problem in Chongqing after noise and air pollution.Responses to cooking exhaust pollution vary with different sex,age and residential environment.This paper concludes by analyzing reasons for ineffective solutions to the cooking exhaust pollution problem in Chongqing and puts forward corresponding new countermeasures.     

中国农田污染评价与防治道路探究

中国农田污染防控是农业可持续发展、农产品安全和国家生态环境安全的重大需求。中国农田污染的特征为：农田污染物种类增多、污染呈现扩张化、复杂化与不断加剧的趋势,同时,治理的难度不断加大。目前中国农田污染的基本格局是：局部改善,整体恶化,虽然仍是可防治的,但扭转总体态势和治理的难度将进一步加大;区域间、产业间和作物间的差异很大,不能以点盖面;化肥、农药等是一把双刃剑,应客观评价,高效使用。在对七种典型防治思路分析的基础上,本研究针对中国农田污染防控的薄弱环节,提出了走农田污染综合立体防控的道路,实现中国国情背景下农田污染防治和农业可持续发展的双赢的战略构思。     

城市农业概念的演变及规范发展研究

自从城市农业思想起源以来,其概念几经演变。笔者对国内外关于城市农业概念的不同阐释进行了梳理,并结合中国国情,从3个层面对城市农业的概念进行了重新界定。基于当前国内城市农业发展需求及趋势,笔者研究认为中国城市农业的发展定位应立足于微观城市农业的概念,并提出了把城市家庭休闲农业作为中国未来城市农业发展与研究重点的新思路。同时从相关法律法规完善、学科融合、科技发展、市场培育等方面,提出了规范中国城市农业发展的对策建议。     

论中国粮食安全的观念、制度与技术创新

针对当前中国粮食安全形势和未来发展趋势,提出中国粮食安全的观念、制度与技术创新思路。在粮食安全观念创新上,要树立“大粮食”观念,逐步实现粮食的数量安全、经济安全和营养安全三级目标,确保粮食增产与增收同步,并重点保障口粮安全,开放非口粮市场。在粮食安全的制度创新上,要推进土地股份合作制,强化耕地评审管理制度,建立和健全粮食安全监测预警体系、粮食市场购销体系、农产品质量标准体系,强化粮食产购中的调控与管理力度。在粮食安全的技术创新上,着重调整粮食产销的区域布局,推行多熟超高产生产技术,构建“大粮食”生产结构。     

欧美地下水硝酸盐污染防治研究进展

鉴于中国地下水硝酸盐污染状况严重,如何预防与治理意义非常重大;为了更好地借鉴欧美发达国家预防治理地下水硝酸盐污染的成功经验,文章在大量检索国外相关科技文献基础上,采用文献研究法对欧美地下水硝酸盐污染状况、预防措施及治理方法进行了比较分析;结果表明欧美地下水硝酸盐污染状况普遍存在、相关法律规则制定全面而且较为注重污染发生前的监测与预防工作。污染的治理因地制宜,对于小范围污染常用的硝酸盐清除技术主要有离子交换法、反向渗透法和生物脱氮法等;对于大面积污染运用的较多的是针对含水土层进行原位脱氮技术,主要包括在水井中添加液体有机碳化合物或者是在地下利用含有有机碳的材料制作渗透反应墙来进行硝酸盐去除。     

中国饲料粮消费问题探析

为了准确分析中国当前饲料粮供需情况及影响因素,首先通过供给法计算出1984—2013年的狭义饲料粮可供给数据,其次通过需求法计算中国饲料粮消费数据。推算得出饲料粮供需数据虽有差距但都呈增长趋势。中国粮食政策加剧了饲料粮供需失衡状况。因此提出相应政策建议:一是适当增加肉类产品进口并严厉打击走私;二是粮食政策在确保主粮(大米和小麦)基本自给基础上,适度进口饲料粮(主要是玉米),并在海关政策制订上将精饲料原料通盘考虑,制订考虑替代品如大麦、高粱、DDGS等在内的一揽子关税与配额政策。     

Numerical Simulation in Flow Field of CNG Vehicle Catalytic Converters

The steady flow in the catalytic converters of CNG was simulated. The gas can breakaway in the entering pipe and the flow of the gas can convergence well in the exhaust pipe. The flow distributing mainly depends on the flow capability of the expanding pipe. The pressure falls apparently in the carrier of catalytic converters. The noble metals in the center of the catalytic converters are consumed more quickly than the edge zone.     

Effect of Reinforced-Concrete Deterioration on Structures

s:It is proposed that the research of the structural durability is necessary considering the structural damages under the effect of deterioration of reinforced concrete. The most common reasons, which cause the deterioration of structures in China, are reinforcement corrosion and freeze thaw cycles of concrete. Based on the summarizing of research works of the effect of reinforced concrete deterioration on structures, it is indicated that the structural durability research should be carried out either in view of material science or that of structural science, and should be also considered the interaction of several factors with uncertain nature instead of the determined individual factor analysis. The structural durability of serviceable should be paid much more attention while researching the durability of structural capacity. The effect of reinforced concrete deterioration on structural capacity, rigidity and durability should be researched henceforth.