再议国企

时代的浪潮簇拥着形形色色的企业在市场海洋中奋力前行,这就是大浪淘沙。今天,在世人的喋喋不休中,国企又一次站在时代的风口浪尖,面临前所未有的关注和争议,前所未有的挑战和压力。近日,据专业机构统计,已公布或披露年报(预报、快报)的1886家上市公司中,有16家公司的亏损额超过10亿元,有42家公司的业绩下降幅度超过1000%。这其中,一些著名国企的名     

“牛”人“微”语

【2013达沃斯张维迎精彩语录】我更奇怪的是,包括我们总理,还有在座的人,所有人天天盯着当天的GDP数字;现在太多的人,从上到下都在被眼前的东西指挥着走,我们为什么不能够看得更远一点?——@中国经济学人【2013达沃斯张维迎精彩语录】好多人误以为国有企业就是全民的企业,就是老百姓的企业,从来都不是这样,国有企业其实只是有利于少数人,而不是有利于多数人,它破坏了社会的公平,也伤害了社会的道德,腐败只是问题的一个方面,国有企业的负面影响我们一般都看不到,包括人事任命、工作安排等等。     

介绍一种制作简易的硅碳棒接头

硅碳棒接头的好坏,直接影响到管式高温炉的正常工作和硅碳棒的使用寿命。我们试制了一种制作简易的接头。在炉温处于1200～1300℃连续工作的条件下,使用这种硅碳棒接头,不易氧化,不会因跳火而烧坏,接触良好,安全可靠,使用寿命长,效果非常好。 制作方法是:用箱形电阻炉的废电炉丝(直径2mm,材料为Cr15Ni60或Cr20Ni80的合金)三根(两根长400mm左右,另一根长200mm左右。尺寸仅供参考。),首先,在长     

浅述简笔画在儿童成长中的重要作用

在当今的时代背景下,每个家庭只有一到两个孩子,随着人们生活的日益富足,越来越多的父母开始更加注重孩子的成长与未来,从某种角度上说,孩子的发展质量就预示着家庭的将来。不少年轻的父母＂恨铁不成钢＂,省吃俭用,在孩子身上盲目投资,上各种培训班,学各种专业技能,期待把孩子培养成＂绝世全才＂,但这股一浪高过一浪的风潮中却隐藏着一定的隐患,家长的选择不适合孩子的实际,选择的专业之多让孩子不堪重负,     

Mn(Ⅱ)-EDTA电位滴定铜的催化指示电极及其应用研究

提出了在氨三乙酸(NTA,活化剂)存在下,以Mn(Ⅱ)催化NaIO4氧化结晶紫的反应指示滴定终点,以自制的结晶紫选择性电极为指示电极,Mn(Ⅱ)为滴定剂,EDTA为阻抑剂,催化滴定测定微量铜的新方法.该方法对试剂用量,酸度,温度,滴定剂浓度,滴定速度及干扰消除等进行了探讨,选择了适宜的实验条件.用于火药中微量铜的测定,样品平均回收率为98.17%,相对标准偏差为1.02%,结果与原子吸收光谱法测定结果相符.     

氧化镁对高铝渣稳定性影响

 为解决降低成本,拓宽矿源的目的,对高铝矿终渣进行了细致且系统的研究。通过对黏度曲线的测量,动力学活化能的计算,热力学计算的手段,分析炉渣各组分析出规律及其变化,得出结果：炉渣稳定性与成分有较为紧密的关系,各超大型高炉炉渣成分相差不大,但黏度随温度变化规律确是大相径庭;一般来说,超大型高炉高温时炉渣活度差异较小,在160000~170000J,而在低温时活化能的变化率差异较大;高铝低镁渣的稳定性超过高铝高镁渣,如果能够使高炉中的镁降低可以大幅度提高炉料的冶金性能,降低渣量,是降低成本的有效措施;降低终渣中的镁含量不是否定镁对炉渣稀化作用,恰恰相反,提高渣中镁在液相中的作用效率;高铝渣未必就一定不稳定,应适宜调整炉渣其他组分,使高炉适应高铝渣操作。     

全球白银的供求形势

1需求形势据国外媒体报道,2003年全球制造业对白银的需求量已上升到24358t,扭转了前两年连续下降的趋势。同时,白银的市场价格也平均上涨了6%。报道说,由于全球电子工业生产的上升和经济环境的好转,2003年,全球工业应用白银的数量增长了3%,达到9957t。中国2003年的白银消费量达到它空前的高水平,制造业对白银的需求量实际上升8%,工业用银数量达到了782t。报道说,首饰和银制品是消费白银的主要市场。2003年,这方面对白银的需求量增长了4.1%,实际用银用达到了7844t。增长幅度最大的是中国和泰国,中国上升22%,泰国上升13%。具有白银首饰消费传…     

攀长钢万吨钛材生产基地规划

本文介绍了攀钢集团四川长城特殊钢股份有限公司万吨钛材生产线的建设方案,说明了该项目具有国际先进水平的装机水平,具有资源、技术和成本等优势,产品多样化,质量高,具有很强的竞争力.并指出该项目的建设将提高我国钛工业的整体水平,有利于我国的经济建设和国防建设,逐步改变世界钛材生产的格局,提高中国钛材生产的国际地位.     

南非黄金生产现状

据国外媒体报道,2004年,南非的黄金生产降到了1931年以来的最低点——342t/a。从1885年南非矿山协会开始对采矿业建立官方统计以来,每年出口额最大的是黄金。现在,这个状况已经发生了变化,铂族金属的出口额已经超过黄金,占第一位。2004年,南非的矿业生产总额是1250亿兰特,黄金产值占293亿兰特,落后于333亿的铂族金属,居第二位。当年南非煤炭产值是276亿兰特。1970年代,南非的黄金产量是1000t/a,占当年全球矿山新生产的黄金的70%左右,一段时期以来,南非的黄金生产以每年5%的速度萎缩,而且近几年来,由于南非货币兰特处于强势,使这种萎缩的速度…     

浅谈摄影作品中如何科学运用线条和光线

人们常说,画家所面对的挑战,是怎样在一张空白的画纸上,加上一些东西来使它变得有艺术性：而摄影师所面临的挑战则是迥然不同的,他们要从杂乱的环境中,充分运用构图技巧,把其中无关的景物除去,使画面看来具有艺术性。换句话说,作画是从一个空白的画面开始,然后决定把一些东西加进画面内,来表达自己的意念。摄影师所关注的,就是怎样安排现有景物内的元素,借以表达自己的意念。     

无线能量传输技术及其在扭矩监测系统中的应用

为了向安装在旋转部件上的监测系统持续稳定地输送能量以保证其正常工作,提出了基于微带天线的能量传输技术,并根据实际应用的要求设计了能量传输系统的总体方案.对于发射天线的馈源问题,提出了一种分散式的供源方案,并对单对天线、多对天线的能量传输情况进行了研究.分析了交错速度对能量传输系统的影响.结果表明,采用本方案来传输能量可以满足实际应用需要.     

Adherence-related behavior in adolescents with asthma: results from focus group interviews

OBJECTIVE: To describe the factors that contribute to vertical transmission of human immunodeficiency virus (HIV) and review means of decreasing the risk of transmission. STUDY DESIGN: Medline search of the international English-language literature pertaining to HIV in pregnancy from 1989 to the present. Special emphasis was placed on articles published in the last three years related to vertical transmission as well as to antepartum, intrapartum and postpartum management to reduce transmission. RESULTS: High levels of maternal viral load and more advanced maternal disease are associated with a greater risk of vertical transmission of HIV. Antepartum and intrapartum maternal treatment with zidovudine and postpartum neonatal zidovudine treatment decreases the risk of transmission by two-thirds, at least in patients with earlier stages of the disease. Breast-feeding is a source of postpartum HIV transmission and may double the total transmission rate. CONCLUSION: Zidovudine should be used in pregnancy to decrease the viral load and reduce transmission of HIV to the fetus. Other antiviral agents should be used during pregnancy if indicated, although current information is lacking about their effects on the fetus and any potential benefits in decreasing vertical transmission of HIV. Breast-feeding should be avoided.     

Assignment of a component of serine proteinase fluorescence spectrum to a cluster of tryptophan residues

An increasing body of information regarding risk factors for perinatal HIV transmission suggests the use of logical management strategies during the prenatal period and parturition directed at maximizing maternal health and minimizing perinatal transmission. This article reviews the recommendations for pharmacologic therapy and rational obstetric management strategies to decrease perinatal HIV transmission based on published clinical trials and a review of data relevant to transmission.     

Transmission Asset Investment in Electricity Markets

We construct a general analytic framework for the transmission network investment problem in the market environment and demonstrate its application to some test systems. We define a set of metrics to quantify the improvement attained in terms of welfare for all the participants and make use of them in the evaluation of the impacts of new transmission investments under competition. The proposed metrics are useful to the central entity responsible for transmission planning to provide meaningful measures of the effects of a modification in the grid over the planning horizon. The proposed framework is particularly useful to transmission network planners to support desired environmental targets. The analysis of the effects of new investments on the participants affected by the expansion includes the assessment of appropriate environmental attributes. The consistency of the measured values in terms of these metrics allows the comparison of disparate transmission investment projects and their effective prioritization. A key element of the framework is the deployment of an optimization scheme to maximize the social welfare with and without the transmission asset investments under various bidding behaviors of the market players and contracting conditions. We report the application of the proposed framework to investigate several transmission expansion scenarios on the IEEE 24-bus reliability test system network. The results on both pool-based markets and combined pool-bilateral contract markets provide a good illustration of the capability of the framework to effectively address realistic questions in transmission investment.     

轧钢机主传动系统的故障诊断

通过对轧钢机主传动系统的振动测试与分析，准确地找到了故障源，并提出了具体的维修建议     

Impact of Market Uncertainty on Congestion Revenue Right Valuation

Congestion revenue rights (CRRs) are property rights that entitle and/or obligate their holders to receive specified (possibly negative) congestion revenues. They provide price certainty for transmission customers who need to purchase open access transmission service. Auctions and bilateral transactions allocate CRRs to market participants who value the transmission rights the most. If valued correctly, CRRs would yield market signals required in valuing congested transmission facilities and inducing capital investment in the transmission sector. Financial transmission rights (FTRs) and flowgate rights (FGRs) are two specific forms of CRRs. This paper presents a simulation based approach for valuing FTRs and FGRs. Using the proposed approach, we derive the probabilistic characteristics of FTR and FGR values under market uncertainties resulting from fluctuating system loads, varying fuel prices, and other system contingencies such as unplanned transmission circuit and generator outages. A theoretical framework consisting of a multilateral-transaction model, a nonconforming electric load model, and CRR valuation models under different market structures incorporating market aforementioned uncertainties is proposed. A Monte Carlo simulation procedure is employed to obtain the distributions of FTR and FGR values. Numerical implementation of the proposed approach is illustrated on a sample test system.     

弧齿锥齿轮在φ2.2M圆锥破碎机的应用

φ2.2M弹簧圆锥破碎机传动轴部的传动齿轮为直齿锥齿轮传动,相互啮合的轮齿是线接触,由于齿轮制造,安装的误差以及传动时的变形,容易产生仅轮齿一端接触的现象,从而引起载荷集中,传动不平稳,承载能力低,传动效率也比较低,容易产生断齿等现象.通过改造直齿锥齿轮传动为格里森弧齿锥齿轮传动,提高齿轮的重合度,从而增大了接触比,减轻了冲击,使传动更平稳,并且降低了噪音:负荷比压降低,磨损较均匀,相应增大了齿轮的负载能力,使用寿命更长:并且可以进行齿面的研磨,以降低噪音,改善接触区和提高齿面光洁度.     

Maternal virus load and perinatal human immunodeficiency virus type 1 subtype E transmission, Thailand. Bangkok Collaborative Perinatal HIV Transmission Study Group

To determine the rate and risk factors for human immunodeficiency virus (HIV)-1 subtype E perinatal transmission, with focus on virus load, pregnant HIV-infected women and their formula-fed infants were followed prospectively in Bangkok. Of 281 infants with known outcome, 68 were infected (transmission rate, 24.2%; 95% confidence interval, 19.3%-29.6%). Transmitting mothers had a 4.3-fold higher median plasma HIV RNA level at delivery than did nontransmitters (P<.001). No transmission occurred at <2000 copies/mL. On multivariate analysis, prematurity (adjusted odds ratio [AOR], 4.5), vaginal delivery (AOR, 2.9), low NK cell percentage (AOR, 2.4), and maternal virus load were associated with transmission. As RNA quintiles increased, the AOR for transmission increased linearly from 4.5 to 24.8. Two-thirds of transmission was attributed to virus load>10,000 copies/mL. Although risk is multifactorial, high maternal virus load at delivery strongly predicts transmission. This may have important implications for interventions designed to reduce perinatal transmission.     

Vertical transmission of HIV-1 infection. Diagnosis and prevention

With an increase in the number of women of childbearing age being infected with HIV-1, the incidence of pediatric AIDS is rising precipitously. Therefore, it is necessary to identify the risks and the potential preventive methods that may be effective in decreasing the transmission from mother to child, i.e., vertical transmission. Administration of zidovudine has been demonstrated to significantly lower the rate of vertical transmission. Passive and active vaccination may also be useful in diminishing the transmission rate. Likewise, methods which provide a rapid and predictive measurement of the likelihood of vertical transmission, such as qualitative and quantitative differences in anti-HIV-1 maternal antibodies between transmitters and nontransmitters, have potential clinical utility.     

Φ3.6 m×14 m实心胶轮传动圆筒混合机在冶金企业中的应用优势

结合河南某冶炼厂混矿生产的特点,对Φ3.6 m×14 m圆筒混合机的齿轮传动、实心胶轮传动和充气轮胎传动等三种传动方式的结构和特点进行对比分析。经过综合分析,实心胶轮传动圆筒混合机在这种混矿生产中具有运行稳定、振动小、噪声低、初期投资少、制造周期短、运行成本低、故障率低、维修简单、节能等优点。