基于Matlab Web Server的试卷分析与评价

结合Matlab的计算能力和Web浏览器的远程访问能力,建立了基于Web的试卷分析与评价系统。实验表明,该方法易于实现试卷分析与评价的各项指标的计算,尤其是正态分布指标,并借助于Matlab强大的计算与图形展示功能,以图文并茂的方式返回到用户面前。     

基于虚拟仪器和神经网络的禽蛋检测系统设计

文针对现有禽蛋无损检测方法系统集成度不高,操作界面易用性差,测量误差大、试验效率低等不足,研制了基于Lab Windows/CVI的多传感器融合的禽蛋无损检测虚拟仪器品质分级系统。该系统以Lab Windows/CVI软件为设计操作平台,以MATLAB神经网络的分析算法为分析模块核心,充分结合计算机视觉检测和声学检测方法的优点,在无损检测的信息采集和处理层面实现了多传感器融合。系统通过系统静态分级测试,系统动态分级测试和系统连续动态测试等3种测试,测试结果表明该系统界面易用性好,在快速运行（27个样品/min）的情况下具有较好的准确度 (系统连续动态测试准确率大于90%),和漏检率（最高速情况下小于3%）。     

联合收割机行走半轴载荷测试系统构建与性能试验

为了给联合收割机行走半轴载荷谱的编制提供真实全面的载荷—时间历程,需要准确获取联合收割机行走半轴在典型作业工况下的载荷信号。该文在分析联合收割机工况特点和行走底盘结构特点的基础上,基于无线传感测试技术,通过选用合理的扭矩、转速传感器和数据采集系统,构建了一种联合收割机行走半轴扭矩和转速无线测试系统,并以沃得巨龙280型履带式联合收割机为样机搭载该系统,并进行了载荷测试性能试验,分析了该样机行走半轴在不同路面起步、直行、转弯时的扭矩和转速,确定了载荷测试性能的稳定性和可靠性。试验结果表明,该载荷测试系统方案合理、技术可行,所获数据稳定可靠。     

滴灌系统压力调节器的研制及水力性能试验研究

滴灌系统管网的压力损失引起的压力偏差，是造成灌水不均匀的主要原因之一。该文介绍了一种能够稳定压力的装置及其结构，通过对其水力性能的测试和分析，提出了该装置适宜的工作范围，同时对测试过程中出现的若干问题进行了探讨。     

基于虚拟仪器技术的声强法识别拖拉机噪声源

识别拖拉机主要噪声源是解决拖拉机噪声问题的首要条件，利用声强法能有效地识别拖拉机主要噪声源。基于虚拟仪器LabVIEW，建立了一套神牛SN250拖拉机噪声信号测试系统，可对拖拉机噪声信号进行测定，并利用声强方法进行噪声频谱分析和声源识别，以分析拖拉机的主要噪声来源。结果表明：所建立的测试系统可满足工程精度要求，能有效识别拖拉机主要噪声来源；排气噪声、发动机散热风扇噪声及发动机机罩振动噪声为拖拉机主要噪声源，声强级分别为106dB、104dB、104dB；排气噪声是驾驶室内主要噪声来源。因此，解决该拖拉机噪声问题须首先降低排气噪声、发动机散热风扇噪声和发动机机罩振动噪声。     

小型拖拉机发动机功率油耗计算机辅助测试系统的研制

在吸收机械式功率、油耗测试仪的基础上，利用机电一体化等先进技术，研制成一套小型拖拉机发动机功率、油耗计算机辅助测试系统。实现了对功率、油耗、转速的计算机辅助测试及曲线绘制。该系统采用了动态实时图像显示技术及在线数字屏幕输出，提高了系统的实用性。     

基于喷油脉宽测试法的汽车油耗智能测试技术

针对汽车油耗测试存在的问题,采用单片机控制技术,通过直接测试喷油器喷油脉宽测试汽车油耗,研制汽车油耗智能测试仪器。根据汽车发动机喷油器喷油控制原理,确定汽车油耗测试方法。基于油耗测试原理构建汽车油耗测试系统的数学计算模型,并在标准状态下对该数学模型进行修正。根据油耗测试系统的功能要求,选定汽车油耗测试控制系统的单片机型号,确定汽车油耗测试控制系统各组成模块的功能,编写了喷油脉冲信号采集系统和汽车油耗测试系统主程序。结合汽车油耗测试样机和汽车测功试验台,搭建油耗测试样机试验系统,对试验数据进行处理分析,汽车油耗测试样机的相对误差可达到0.46%;喷油器特性参数受发动机转速变化影响较大,会影响到汽车油耗测试精度,需要对发动机不同转速条件下的喷油器特性参数进行修正,可进一步提高汽车油耗测试精度。该研究可为研制高精度、智能型汽车油耗测试仪器提供参考。     

基于微处理器的红外监测系统识别母猪发情

正确识别母猪正常发情是获得母猪适期配种时间和提高其受胎率的技术关键。目前大部分种猪场识别母猪发情仅依靠人工观察的手段来完成。该文介绍了采用微处理器控制的红外监测系统自动识别母猪的发情。详述了该系统的结构设计，包括红外传感与检测电路的设计，微处理器的红外信号采集与存储电路的设计等，以及用于识别母猪发情的应用原理。该系统在经过种猪场现场测试，分析其试验结果后表明：红外监测系统识别母猪正常发情的准确率达到80％以上，并可有效地减少了母猪非生产繁殖的天数与投入的人工费用。     

连栋温室热水供热系统散热管道传热系数的计算与测试

设施农业是我国现代化进程中的一个重要内容，现代化温室作为设施农业的标志，正在受到大力发展和重点研究。为了对温室热水供热系统散热管道的热工性能进行研究和测试。论文主要进行了以下工作：对温室热水供热系统散热管道的热工性能进行理论分析和计算；在密闭小室内，对温室散热管道热工性能进行实际测试。通过理论计算与实际测试，得出了散热管道传热系数的实验公式，并分析了可信性与影响因素。     

锤片式饲料粉碎机内气固两相流场压强的测试方法

粉碎机在工作过程中,粉碎室内部是一个复杂的三维流场,针对这种流场的测试,现有的方法很难对多相流场压力分布进行长时间、全方位的准确测量。为此,该文提出一种基于虚拟仪器技术的流场测试方法,根据该方法构建了一套测试系统,涵盖了仪器选型、数据采集与分析的程序设计等环节。以锤片式粉碎机样机为试验对象,对粉碎室内的流场进行多点测量。对采集到的各个测量位置的压强信号做数字信号处理,并做比较分析。结合前期研究成果,通过单相流对比试验以及流场仿真分析,论证了该测试方法及测试系统的可靠性。此外,该方法的提出和测量系统的开发,为课题组今后研究粉碎室内流场的压强分布规律,寻找压强与粉碎机结构参数之间的关系提供了技术支持,可望为新型粉碎机的优化设计提供理论依据。     

Multielement X-Ray fluorescence analysis of natural waters by using a preconcentration technique with ion exchange resins

The analysis of trace element in different kinds of waters is described, using a preconcentration technique on ion exchange loaded filter papers. The filters were analyzed employing an energy dispersive X-ray fluorescence system characterized by radioisotopic excitation sources and gas proportional or semiconductor detectors. The detection limits of the method were experimentally determined and the elemental levels in typical waters were measured.     

以栾城试验站为研究基地的科研论文发表情况分析

运用CNKI 和ISI Web of Knowledge 两大数据库的文献计量分析工具, 统计了1981 年到2010 年间在中国科学院栾城农业生态系统试验站开展科学研究的科技论文发表情况。结果表明: 所检索到的过去30 年发表的论文为1 151 篇, 其中中文论文920 篇、英文论文231。1981~2010 年, 年度发表论文数量呈稳步增长趋势, 2001年以前发表的科技论文主要以中文论文为主, 2001 年以后英文论文数量逐年增加, 年均增长速度为22.4%; 中文论文2005 年达到高峰后逐年减少。论文作者单位主要集中在河北、北京、山东等地, 与国外合作单位主要集中在日本、美国。论文的关键词出现频率较高的为: 小麦、水分利用效率、玉米、产量、土壤水分等。开展研究所得到的资助项目主要以国家科研计划项目和中国科学院科研计划项目为主, 其次为地方科研计划项目, 国际合作项目相对较少。论文发表的期刊来源主要为:《中国生态农业学报》、《干旱地区农业研究》、《华北农学报》、《Hydrological Processes》、《Agricultural Water Management》、《Plant, Soil and Environment》、《Irrigation Science》。发表论文的平均引用次数为5.6 次, 引用次数超过100 次的论文为6 篇, 引用次数超过50 次的论文为34 篇。     

我国蔬菜硝酸盐积累研究现状调查及发展趋势——基于文献计量学的统计分析

运用内容分析法和文献计量法,对1994~2004年间《中国期刊全文数据库》和《中文科技期刊全文数据库》收录的关于蔬菜硝酸盐累积研究的533篇相关文献进行内容分析和文献计量统计,从文献计量学的视角,揭示了我国蔬菜硝酸盐积累研究的现状及发展趋势,为更加有效、合理、最佳调配科学研究资源提供参考依据。     

Seasonal changes of photosynthetic bacteria and their products

In our preceding papers the distribution (1, 2), ecological problems (3,4), and the products of photosynthetic bacteria (5–8) have been studied. It was also reported that the growth and nitrogen fixation of photosynthetic bacteria were accelerated remarkably in the system of symbiosis with other heterotrophic microorganisms like Azotobacter (9) and Bacillus megaterium (10) ; moreover the products generated by photosynthetic bacteria were used by plants (11) and animals in water (2, 4), directly or indirectly. It is noteworthy that in paddy soil, this bacterial cells have a beneficial effect on the development of grains (11).     

Do gender, nationality, or academic age affect review decisions? An analysis of submissions to the journal Biological Conservation

Recent papers have considered whether the present system of single-blind reviewing results in bias against women or other groups of authors in biological journals. If so, double-blind reviewing might be an alternative approach that avoids such bias. We investigated the effects of gender, nationality (English-speaking countries only), academic age, year of review, and handling editor on the decisions made on a sample of 1856 papers submitted to the journal Biological Conservation between 2004 and 2007. There is no evidence of differences in acceptance rates among genders, nationalities, academic age, or year, nor is there evidence for interactions among these factors. Individual handling editors differed in the proportions of papers that they accepted, rejected following review, and rejected without review, but did not show biases based on any of the factors we examined. Overall, we did not find evidence supporting a change in the present review system, although the low rate of acceptance of papers from certain non-English-speaking countries is an issue that needs to be addressed. We believe that these types of audits of the editorial system are necessary, so that all submitting authors feel that the editorial process is fair, unbiased and rigorous.     

基于文献计量学分析的全球生物质炭研究进展

为了深入了解国内外生物质炭的研究现状与研究热点，为相关研究领域的科研工作者与决策者提供参考，该文以Web of Science 核心数据库为数据源，采用文献计量学方法对2003-2020年间全球发表的生物质炭研究文献进行分析。全球生物质炭研究的发文量呈快速增长趋势，其中中国总发文量和总被引频次均位居世界首位。中国-美国是生物质炭研究最大的合作关系体。发文量最多的机构是中国科学院。中国有8名学者发文量进入世界前20名，上海交通大学曹心德的总发文量和总被引频次位列大陆学者榜首。发文量最大的学科方向是环境科学。中国在生物质炭研究方面发展快、成果产出多，但缺乏有国际影响力的核心成果，在研究创新性和发文质量上还有待提升。关键词分析表明，生物质炭在土壤改良和农业生产中的应用、利用生物质炭处理废水及修复污染土壤，以及生物质炭制备方法和工艺的创新是生物质炭的主要研究热点。而生物质炭制备材料与工艺的创新、各类功能型生物质炭纳米复合材料的开发，以及继续拓宽生物质炭在不同领域的高效利用可能成为今后的研究热点。     

Mechanism of inhibitory effect of allophane and montmorillonite on some enzymes

It is well established that the presence of clay in an enzyme-substrate system may reduce the activity of enzymes (1-3,5,6,8,11-14). This inhibition by the clay would be principally caused by the adsorption of enzyme and/or substrate on the clay particle. In the previous papers (1–3), the activity of some enzymes was found to be inhibited in various degrees by clays. The enzyme appears to be adsorbed on the clay particle in various ways according to the nature of adsorbate as well as adsorbent. This suggests that the enzyme is adsorbed by the clay so as not to combine with the substrate, or that the adsorbed enzyme molecule has a configuration different from that of a free enzyme molecule, reducing the activity of the enzyme.     

Introduction to the special issue on experiences with the impact and prevention of subsoil compaction in the European Union

The papers in this special issue present results of the European Union (EU) concerted action “Experiences with the impact of subsoil compaction on soil crop growth and environment and ways to prevent subsoil compaction”. The results and conclusions of earlier research on subsoil compaction are memorized and it is emphasized that the conclusions are still sound: high axle load traffic on soils of high moisture content causes deep and persistent subsoil compaction. The concerted action on subsoil compaction in the EU and an almost identical concerted action on subsoil compaction in central and eastern Europe are briefly introduced. This special issue presents a selection of papers of the concluding workshop of the concerted action on subsoil compaction in the EU. It includes three papers on modeling the impact of subsoil compaction on crop growth, water availability to plants and environmental aspects; three papers on modeling of subsoil compaction by heavy machinery; four papers on measurement of soil mechanical and physical properties in relation to subsoil compaction and four papers on methods to determine the risk of subsoil compaction and to identify prevention strategies. The trends in agriculture in relation to subsoil compaction are discussed. A positive trend is that policy makers in the EU and worldwide recognize soil as a vital and largely non-renewable resource increasingly under pressure. A negative trend is that wheel loads in agriculture are still increasing causing severe damage to subsoils. The conclusion is that European subsoils are more threatened than ever in history. Manufactures, agricultural engineers and soil scientists should collaborate and research should be initiated to solve this problem and find solutions. Subsoil compaction should be made recognized by all people involved from farmer to policy maker. Therefore an assessment of the existence and seriousness of subsoil compaction throughout Europe should be initiated.     

吸附法固定化绿色木霉(Trichoderma reesei)生长细胞

本文应用辐射技术,在纸表面复盖不同性质的高分子,以此作为固定化生长细胞的载体,吸附绿色木霉细胞,并测定了固定化绿色木霉细胞的纤维素酶活性。当纸复盖有3种亲水性均聚体poly-HEA、poly-HEMA,poly-HPMA和一种疏水性均聚体poly-A4G时,细胞被吸附在这4种载体上,并能产生纤维素酶,但是只有复盖poly-HPMA的载体固定化细胞的纤维素酶活性(FPA)高于游离细胞。当纸复盖不同组成的HEA-A-TMPT、HEMA-A-TMPT.HPMA-A-TMPT和A4G-A-TMPT的共聚体时,用这些载体固定化细胞的FPA均比复盖均聚体的增加。用复盖不同组成的poly(HPMA-A-TMPT)载体固定化细胞,其FPA均比游离细胞增加,最高的增加了60％。用复盖有50％:50％和75％:25％的poly(HEA-A-TMPT)共聚体载体固定化细胞,其FPA分别比游离细胞增加了70％和60％。FPA增加是由于吸附的细胞重量增加,而固定化细胞的重量与复盖于纸上的高分子的性质(例如含水量)有关,复盖的高分子含水量10％左右时,固定化细胞重量最高,在载体表面复盖适宜的高分子有利于细胞的吸附和生长。