生物芯片

基于模拟计算机芯片的设想,将具有生物选择性的生物分子如核酸探针,抗体,肽段等大规模,有序地,集成制作成面积不大的生物芯片,已证明,它可用于核酸测序,基因突变和变异的探测,表达分析和基因多态性研究等,生物芯片的出现,将采集到大量生物信息,从而显著加速新药开发,肿瘤病因研究,传染病诊断,遗传病诊检,动植物品种改良以及加速对人体生理,病理,药理和毒理过程的了解,生物芯片的推广应用将导致生物信息学高潮的到     

农业机械维修与保养浅谈

随着现代农业的不断发展,推进农业机械化事业的开展,要使农民从繁重的劳动过程中解脱,不断提高农业生产效率,加强农业机械的使用,要对农业机械进行定期的维修与保养。因此,本文阐述农业机械维修与保养的具体内容,明确农业机械维修保养的基本要求,遵循科学的原则,要注重“防重于治,养重于修”,对机械进行定期的检查,使其运行的状态处在良好的阶段;分析农业机械维修保养过程中所存在的具体问题,比如机械故障问题,维修人员的技术能力有待提升等,针对所存在的问题,提出农业机械维修与保养的应对对策,从不同的季节、技术层面、经营管理方面、经济方面进行探讨,使得对设备的修理改造更新,获得最佳的方案,从而推动农业机械的优化,进而促进农业的可持续性发展。     

浅析“物资的活化”

生产力的三要素是人、生产资料、劳动对象。通常,人们认为人是占主导地位的活因素,对其较为重视,而对占2／3的物的因素较为忽视,研究甚少,对物的活化更是少有耳闻。目前,企业普遍存在的一种现状,只看重增量投入,而忽视从严管理存量盘活,缺少对现有物资的挖潜和利用,结果是投入盲目,产品滞销,物资闲前浪费,企业负债累累,陷入困境。为此,在当今竞争激烈的经营环境下,企业要生存、发展,必须创新管理,把物的因素活化起来,使企业做到市场反应快,产品转产快,企业发展快。一种物资产品,既包含人的劳动成果,又包含物的多种组…     

浅析红薯种植技术及发展前景

红薯是一种十分普遍的农作物,不但能吃,具有很强的药用价值,还能为种植者带来可观的经济效益,而且红薯对生长环境的要求并不高,种植技术也比较简单,基于此,在我国的农村,红薯成为普遍的种植作物,种植面积广,就红薯的诸多特性,对其种植技术以及发展前景进行分析,旨在提高红薯的产量,优化我国的农业结构,帮助农民脱贫致富,给大众提供参考。     

新时期创新电力工程管理模式的对策

随着社会经济的持续发展,电力工程的规模也在逐渐扩大,电力工程的发展有着巨大的影响,关系着社会的生产与生活,在新时期,创新电力工程管理模式具有深远的意义,是十分重要的,但现阶段,电力工程管理模式存在不足,急需解决,本文将对其不足进行分析,并阐述电力工程管理的创新模式,旨在促进电力工程的持续发展。     

稠油深井泵柱塞维修技术决策分析

在含砂稠油油井的开采中,深井泵的损坏相当严重。实践证明,这种损坏是由砂粒的磨损和腐蚀共同作用的结果,其中最主要的是磨料的磨损。据统计,含砂与不含砂油井相比,前者因深井泵的失效而使修井的次数增加了一倍,购置深井泵的费用明显增加,影响油井正常生产,产量大幅度下降,经济损失不可低估。 目前,在深井泵的修理中,往往只重视衬套的修复,而忽视柱塞的修复,主要原因是修复难度大,缺乏适当的修复技术,没有完善的修复工艺措施。实际上,柱塞的价格约占整台泵的50％,修好一个柱塞比购买一个新柱塞可节约费用16.7％,而修好一个衬套只能节约费用6.7％～10％,可以看出,柱塞的修复比衬套的修复更有价值,应给予高度重视。     

林业病虫害的发生原因及无公害防治对策

现阶段的国家林业发展,正进入到非常重要的阶段,各方面的工作开展,必须从长远的角度来优化、调整,固定的策略和方法,并不能得到优秀的成绩,还会由此表现出较多的缺失、疏漏现象,最终造成的恶劣后果,根本无法在短期内快速的解决。相对而言,林业病虫害的出现,针对林业的健康发展,以及生态体系都会造成严重的破坏,应坚持在具体的解决策略上,做出良好的调整,从正确的思路、方法来出发,确保在林业病虫害的内部解决上,可以由此来得到更好的成绩。就此展开讨论,并提出合理化建议。     

气象预报的方法与不确定性

气象预报的产生,是社会发展、气象科技发展共同的产物。气象预报至今,人类对此项技术进行艰苦的探索,并取得不小的成绩。像是,气象谚语、天气图预报、数值预报等等方法的产生,更是促使气象预报的准确性大大提升。但是,不可置否的是,气象是大气运动的结果,大气作为一个复杂的系统,受初始条件的影响很大。而且,我们的播报同样受数值模式技术水平的限制,存在误差是不可避免的。可以说,较长的一段时间,气象播报的不确定性将长期存在。对此,作为固有存在的现象,广大市民和政府部门,要接受这种不确定性的事实,同时,注意积极研发最新的观测技术,注意气象工作人员的业务培训,对气象播报应更客观有效的利用。     

锅炉的维护——给水处理

一绪言 随着工业的发展,锅炉也成为不可或缺的设备,以我局各厂而谈,差不多都有生产锅炉,又因为锅炉易於出事故,它的维护工作也引起了注意,一般的维护工作只限於定期检修,如隔半年或一段时期就停炉清理,锅垢有多厚,泥沙有多少,锅心腐蚀的不能用了就换锅心,诸如此类的修理,确亦解决了一些问题,不过这是不够的,开用时间的减少,有碍於生产,这是一方面;另一方面,修理费用的增加,锅炉的寿命降低影响了产品的成本;所以说锅炉维护工作的关键问题,是在给水处理,根据客观条件,给水的处理,可以相对地使开用时间延长,修理费的相对减少,锅炉的寿命亦可相…     

国外摩擦磨损润滑文献索引

弹性流体动力润滑 ①“润淆油的流动性与摩擦力的关系”,Ky。-tani,T.辱,《ASLE Trans.》,1987,Vol.30,No .1,1杜~106 ②,’i昆合润汾、徽弹流润滑与工况的关系,’,Baglin,K,P.等,《Tribology—Frietion,Lubrieation and Wear,Fift了,Years on》,1 Mee五E,z犯7,MEP,London,61一70 ③“粗糙表面间干的和有润滑的接触”,TriPp,J.H.等,《同上》,71一79 ④“工作在干燥的弹流润滑下的角接触滚珠软承的油膜厚度测量和分析”,Hunter,S.D.等,《同上》,81一8唤 ⑤“水包油乳化液润滑的弹流接合的膜厚”,Kimura,Y.等,《同上》,85一9。 …     

支持三维CAD的协同设计模式研究

分析了船舶行业对支持三维CAD的协同设计需求的特点。在结合三维CAD需求讨论C／S、B／S模式等两种主要协同设计模式的适用性和局限性的基础上，提出了一种综合利用C／S、B／S的协同设计模式；介绍了基于该模式、支持三维CAD协同设计原型系统的体系结构及其设计思想。     

基于B/S和C/S混合模式下的ERP系统的设计

ERP，即企业资源计划，是20世纪80年代发展起来的集合企业内部和外部所有资源，进行优化和控制，以实现最大效益的管理系统，它代表了未来企业管理的发展方向和必然趋势。本次设计综合考虑了C／S模式高效的事务处理能力以及B／S模式能够借助Internet充分发挥其特点的优势，采用了B／S和C／S混合模式进行ERP系统的设计。     

肝素/硫酸乙酰肝素四糖同分异构体的制备与表征

肝素/硫酸乙酰肝素（Hep/HS）寡糖结构多样,且与生物学、病理学功能息息相关,表征这些结构对解析它们的功能具有重要意义。本实验以市售猪肠肝素钠为原料,制备了9种肝素四糖,并用二糖组分分析方法结合反相离子对试剂色谱-串联离子阱飞行时间质谱(IPRP-LC/IT-TOF MS)进行结构解析。结果表明：9种肝素四糖中有两组同分异构体,且含己胺离子对试剂的RP-LC/MS能够成功分离肝素寡糖及其同分异构体;采用LC-MS/MS方法可以鉴定其中一组同分异构体的结构。该方法可为HS/Hep寡糖的研究提供标准品,并为解析HS/Hep同分异构体结构提供一种简单有效的方法,进而为更好地理解生物体内HS/Hep结构和生理生化功能的关系提供帮助。     

The Use of Ensemble Averaging to Increase the Sensitivity of Measurements with Flame Photometers†

SUMMARY

A number of steps that optimize the signal-to-noise ratio, S/N, were provided in the flame spectrophotometer design, including beam chopping followed by narrow-band-tuned amplification. It has been shown that the relative effectiveness of three methods of optimizing or enhancing S/N to increase the sensitivity and decrease the lower limit of detection of flame photometric measurements increases in this order: linear detection followed by RC filter averaging; linear detection followed by RC filter averaging followed by active integration averaging; ensemble averaging of output of tuned amplifiers. Correlation in both the frequency and time domains is provided, respectively, by tuned amplification and by ensemble averaging. Other advantages of the use of ensemble averagers in flame photometry are pointed out, including correction for background, calibration in the sample matrix, data transformations, faster wavelength scanning without S distortion, testing of design steps to optimize S/N, digital data acquisition, and the attainment of a greater advantage from the dependence of multiplier phototube gain upon the spectral sensitivity of the photocathode and upon the voltage applied to the tube. To obtain measurements of highest sensitivity, all portions of the measurement system must be designed to optimize S/N wherever economically and technically feasible in order to obtain a system output that has the highest S/N. The enhancement of the optimized S/N by ensemble averaging can provide a further increase in the sensitivity of measurement, or, in a practical problem, enhancement of S/N by ensemble averaging may be attractive because of the achievement of sufficiently high sensitivity (and low detection limits) with the use of relatively simple procedural steps.     

Root cause of thermal sleeve loosening in optimized power reactor 1000 unit 5 and 6 Part (I)

Abstract Four of safety injection (SI) nozzles in a 1000 MWe-class Optimized Power Reactor (OPR-1000) are fitted with thermal sleeves (T/S) to alleviate thermal fatigue. Thermal sleeves in #3 and #4 of Younggwang (YGN) & Ulchin (UCN) nuclear power plant are manufactured out of Inconel-600 and fitted solidly without any problem, whereas YGN and UCN in #5 and #6, also fitted with thermal sleeves made of Inconel-690 for increased corrosion resistance, experienced a loosening of thermal sleeves except T/S of YGN #5-1A. To identify the root cause of T/S loosening, three suspected causes were analyzed: (1) the shear force of flow on the T/S when the safety SI nozzle was in operation, (2) the differences between Inconel-600 and Inconel-690 in terms of physical and chemical properties (notably the thermal expansion coefficient), and (3) the positioning error in explosive expansion of the T/S as well as the asymmetric expansion of T/S. It was confirmed that none of the three suspected causes could be considered as the root cause. However, after reviewing the design change history from the Palo Verde nuclear power plant to YGN and UCN #3,4 and #5,6, it was realized that the two stage design modifications (in terms of groove depth & material) made an additional explosive energy required by 172% in aggregate, but the amount of gunpowder and the explosive expansion method were the same as before, resulting in insufficient explosive force that led to poor thermal sleeve expansion. T/S measurement data and rubbing copies also support this conclusion. And the T/S loosening was also attributable to lenient quality control before and after fitting the T/S that resulted in significant uncertainty. In addition, it is our judgment that the acceptance criterion applicable to T/S fitting was not strict enough, failing to single out thermal sleeves that were not expanded sufficiently. Lastly, the acceptance criterion was scientifically revised to incorporate the thinning effect and inherent uncertainties of measurements.     

Antibacterial activity of chlorhexidine after final irrigation with ethanol: CLSM and culture‐based method analysis

This study investigated the effect of 95% ethanol on the antibacterial properties of 2% chlorexidine (CHX) over monospecies biofilm (Enterococcus faecalis) through a culture‐based method, and over multispecies biofilm using confocal laser scanning microscopy (CLSM). For monospecies model, E. faecalis biofilm was induced in 40 root canals. The irrigation procedures were: S—saline solution; S/CHX—saline solution + CHX; E—ethanol; and E/CHX—ethanol + CHX. Microbial sampling was performed at three periods: before (S1), immediately after (S2), and 72 h after the final flush (S3). For multispecies biofilm model, 28 sterilized bovine dentin blocks were fixed on a removable orthodontic device to allow intraoral biofilm development. Seven samples were used in each group. Statistical analysis was carried out by using the Kruskal–Wallis test and Dunn's test for multiple comparisons. There was a significant reduction in CFUs count immediately after the final flush (S2) in all experimental groups (P < 0.05). However, only S/CHX, E and E/CHX groups had CFU counts close to zero, without differences among them (P > 0.05). After 72h (S3), the S/CHX and E/CHX groups had CFU counts near zero (P > 0.05). The CFU count increased in S3 for S and E groups (P < 0.05). CLSM showed that the percentages of remaining live cells were similar in S/CHX, E, and E/CHX groups (P > 0.05). The S group had the highest percentage of live cells (P < 0.05). The 95% ethanol did not interfere in the antibacterial properties of 2% CHX over mono‐ and multispecies biofilms. Microsc. Res. Tech. 78:682–687, 2015. © 2015 Wiley Periodicals, Inc.     

C/S与B/S混合模式下通信器材网络管理设计

根据当前军队信息化建设发展的需求,提出了基于C/S结构与B/S结构相结合的方法建立军队中等规模通信器材网络资源管理系统.用户利用B/S结构通过浏览器访问Web服务器,其次通过Web服务器访问SQL服务器数据库,用户利用C/S结构通过访问应用服务器,从而最终达到访问数据服务器.在C/S与B/S模式下,分别使得通信器材网络管理系统把准确的器材战术性能指标以及修理情况,实时的器材进出库信息、全面地科学地展示给使用人员,其次该系统能够提供有限的预测分析性能,为器材的申请、发放、修理提供必要的有用信息.     

基于网络化仪器的计量校准方法研究

针对传统计量校准方式不足,说明网络化远程计量校准技术的优越性。从计量角度论证了通过Internet进行网络化远程校准的可行性,分析远程网络化计量校准的实现条件、网络接入方法。针对各种总线式计量校准仪器和独立的网路功能仪器,提出详细的系统网络接入改造方式。采用C/S、B/S、CB/S等混合模式构建网络化计量校准模型,详细论述了基于网络化仪器的网络化计量校准的技术手段和实现方法。     

Laser diode modulation under multichannel digital 64-QAM and 256-QAM TV signals

A simulation model for laser diode modulation by multichannel 64-QAM and 256-QAM TV signals is developed. The signal/noise (S/N) ratio is used as a criterion for evaluating the quality of TV signals. The effect of nonlinearity of the light-current characteristic on the S/N ratio is studied. Simulation results are presented in the form of a dependence of the maximum number of transmitted channels on the optical modulation depth with certain requirements for S/N. The simulation model is implemented in the object-oriented programming language Delphi 7.