浅谈施工过程质量控制的实践和体会

施工阶段是工程项目质量的实际形成阶段。施工阶段的质量控制是整个项目质量控制的重点控制阶段。在这个阶段,人们习惯于根据工程实体质量形成的时间,将其分为质量的事前控制、事中控制和事后控制,这是无可非议的。     

工程项目的施工质量控制

工程项目的施工过程是形成工程项目实物的过程 ,其使用功能能否满足需要和潜在需要 ,项目的施工质量起着决定性的作用。由于工程项目涉及面广 ,加上工程项目的施工特点 ,工程项目的施工质量较一般工业产品的质量更难于控制 ,因此 ,项目施工质量的控制成为施工企业的难点问题。每个施工企业的质量管理模式不管是何种 ,都会在长期的施工中形成自己企业特色的项目质量控制方式。企业项目施工质量的控制方式 ,不管采取何种形式 ,但究其实质都是在企业的总质保体系中 ,如何建立健全项目的质量保证机构 ,在施工准备阶段如何进行质量的预控制和在施…     

浅析不同阶段的工程造价管理

工程造价管理是加强工程项目投资控制,优化工程项目资源配置,提高工程项目综合管理能力的重要手段。通过从项目的决策阶段、设计阶段、施工阶段、竣工验收阶段,以及项目建成后使用阶段进行全过程的造价控制,以达到提高过程质量、加快施工速度、降低工程造价的目的。     

海洋石油工程项目质量管理体系构建

海洋石油工程项目是一项综合性较强的工程。在施工的过程中,为了保证海洋工程能够顺利、高效实施,应构架成熟、完善的项目质量管理体系。加强对施工各个阶段质量的控制,保证整体项目的施工质量。本文从海洋工程设计施工材料的选择、施工阶段的质量控制,如何形成完善质量管理体系,进行了深入的分析。为海洋工程项目构建成熟的质量管理体系提供了宝贵的借鉴经验。能够不断促进海洋石油行业的持续、健康发展。     

工程建设施工阶段的投资控制

近年来，随着我国体制改革的进一步深化，很多建设项目都采用了建设监理制。其中心任务即控制工程项目目标，也就是控制经过科学地规划所确定的工程项目的投资、进度和质量目标。三大目标之间是相互关联、互相制约的目标系统。在项目建设的全过程中，投资决策阶段和设计阶段是节约项目投资的决定阶段，而建设项目的投资主要发生在施工阶段，在这一阶段中，尽管节约投资的可能性已经很小，但浪费投资的可能性却很大。在我国目前监理工作还主要是在施工阶段。     

项目成本控制研究的理论基础

本文对建设工程施工阶段的基本资金管理与控制进行研究,施工建设的工程项目施工阶段基本资金控制是施工建设的工程项目实施阶段造价控制的关键,施工基本资金占建设总费用的很大比重,关系到整个项目的经济效益。建筑工程绝大部分的基本资金支出发生在施工阶段,施工基本资金控制是每个施工企业关注的焦点,它是现代施工企业经营的核心内容,对提高企业经济效益和竞争力起着举足轻重的作用。     

攀钢RH真空精炼炉用耐火材料的长寿化实践

截至2008年,攀钢提钒炼钢厂已建成投产了3座RH真空精炼炉(1座板坯RH炉,2座方坯RH炉),形成了LD-LF-RH-CC全连铸模式.攀钢RH炉真空室底部、中部、上部为整体,插入管与真空室的连接为焊接式.在这3座真空RH炉引进和投产运行过程中,其耐火材料的使用主要存在如下亟待解决的问题:     

房地产工程项目实施阶段工程造价的控制研究

对于房地产工程项目而言,其工期长,投入成本较多,因此就应该对房地产工程项目进行有效管理,控制其造价,减少成本支出,为房地产企业获取更多的经济效益。其工程造价的控制,也就是在保证房地产工程项目施工质量的基础上,能够在各个阶段来对其成本进行有效控制,进而让每一阶段的造价都在合理的范围内。本文就先了解工程项目实施阶段工程造价的相关内容,然后说明房地产工程项目实施阶段工程造价控制的相应策略,为房地产工程项目造价控制提供参考。     

浅谈工程量清单计价模式下的工程投资控制

随着我国加入世界贸易组织，建设工程计价与国际接轨，全面实行工程量清单计价已是大势所趋势，本文通过对工程量清单计价特点的分析，从项目实施过程四个阶段即工程项目招投标前准备阶段，工程项目招投标阶段，工程项目合同实施阶段（即施工阶段），工程项目竣工结算阶段来具体分析如何做好工程量清单计价模式下的投资控制。     

路桥工程施工阶段的工程造价控制要点分析

路桥工程项目施工建设的重要性是毋庸置疑的,其中的造价控制环节更是重中之重。面对复杂、多变的施工环境情况,需要系统分析并掌握工程施工阶段的造价控制要点,才能达到既定的工程造价管控目标。本文通过概述路桥工程项目施工时期造价管控的相关内容,分析了路桥工程项目施工时期的造价管控要点,从而有效提升路桥工程施工阶段的造价控制水平。     

Many Drugs of Abuse May Be Acutely Transformed to Dopamine,Norepinephrine and Epinephrine In Vivo

It is well established that a wide range of drugs of abuse acutely boost the signaling of the sympathetic nervous system and the hypothalamic–pituitary–adrenal (HPA) axis, where norepinephrine and epinephrine are major output molecules. This stimulatory effect is accompanied by such symptoms as elevated heart rate and blood pressure, more rapid breathing, increased body temperature and sweating, and pupillary dilation, as well as the intoxicating or euphoric subjective properties of the drug. While many drugs of abuse are thought to achieve their intoxicating effects by modulating the monoaminergic neurotransmitter systems (i.e., serotonin, norepinephrine, dopamine) by binding to these receptors or otherwise affecting their synaptic signaling, this paper puts forth the hypothesis that many of these drugs are actually acutely converted to catecholamines (dopamine, norepinephrine, epinephrine) in vivo, in addition to transformation to their known metabolites. In this manner, a range of stimulants, opioids, and psychedelics (as well as alcohol) may partially achieve their intoxicating properties, as well as side effects, due to this putative transformation to catecholamines. If this hypothesis is correct, it would alter our understanding of the basic biosynthetic pathways for generating these important signaling molecules, while also modifying our view of the neural substrates underlying substance abuse and dependence, including psychological stress-induced relapse. Importantly, there is a direct way to test the overarching hypothesis: administer (either centrally or peripherally) stable isotope versions of these drugs to model organisms such as rodents (or even to humans) and then use liquid chromatography-mass spectrometry to determine if the labeled drug is converted to labeled catecholamines in brain, blood plasma, or urine samples.     

Sapindaceae,cyanolipids, and bugs

Scentless plant bugs (Heteroptera: Rhopalidae) are so named because adults of the Serinethinae have vestigial metathoracic scent glands. Serinethines are seed predators of Sapindales, especially Sapindaceae that produce toxic cyanolipids. In two serinethine species whose ranges extend into the southern United States,Jadera haematoloma andJ. sanguinolenta, sequestration of host cyanolipids as glucosides renders these gregarious, aposematic insects unpalatable to a variety of predators. The blood glucoside profile and cyanogenesis ofJadera varies depending on the cyanolipid chemistry of hosts, and adults and larvae fed golden rain tree seeds (Koelreuteria paniculata) excrete the volatile lactone, 4-methyl-2(5H)-furanone, to which they are attracted.Jadera fed balloon vine seeds (Cardiospermum spp.) do not excrete the attractive lactone. Loss of the usual heteropteran defensive glands in serinethines may have coevolved with host specificity on toxic plants, and the orientation ofJadera to a volatile excretory product could be an adaptive response to save time.Mention of a commercial product does not consititute an endorsement by the USDA.     

2008～2009年世界塑料工业进展

收集了2008年7月～2009年6月世界塑料工业的相关资料,介绍了2008～2009年国外塑料工业的发展情况,提供了世界塑料产量、消费量及全球各类树脂的需求量及产能情况。按通用热塑性树脂(聚乙烯、聚丙烯、聚苯乙烯、聚氯乙烯、ABS树脂)、工程塑料(尼龙、聚碳酸酯、聚甲醛、热塑性聚酯、聚苯醚)、特种工程塑料(聚苯硫醚、液晶聚合物、聚醚醚酮)、通用热固性树脂(酚醛、聚氨酯、环氧树脂、不饱和聚酯树脂)不同品种的顺序,对树脂的产量、消费量、供需状况及合成工艺、产品应用开发、树脂品种的延伸及应用的进一步扩展等技术作了详细介绍。     

Direct observation of freeze-thaw instability of latex coatings via high pressure freezing and cryogenic SEM

Despite its industrial importance, the subject of freeze-thaw (F/T) stability of latex coatings has not been studied extensively. There is also a lack of fundamental understanding about the process and the mechanisms through which a coating becomes destabilized. High pressure (2100 bar) freezing fixes the state of water-suspended particles of polymer binder and inorganic pigments without the growth of ice crystals during freezing that produce artifacts in direct imaging scanning electron microscopy (SEM) of fracture surfaces of frozen coatings. We show that by incorporating copolymerizable functional monomers, it is possible to achieve F/T stability in polymer latexes and in low-VOC paints, as judged by the microstructures revealed by the cryogenic SEM technique. Particle coalescence as well as pigment segregation in F/T unstable systems are visualized. In order to achieve F/T stability in paints, latex particles must not flocculate and should provide protection to inorganic pigment and extender particles. Because of the unique capabilities of the cryogenic SEM, we are able to separate the effects of freezing and thawing, and study the influence of the rate of freezing and thawing on F/T stability. Destabilization can be caused by either freezing or thawing. A slow freezing process is more detrimental to F/T stability than a fast freezing process; the latter actually preserves suspension stability during freezing. Presented at the 82nd Annual Meeting of the Federation of Societies for Coatings Technology, October 27–29, 2004 in Chicago, IL. Tied for first place in The John A. Gordon Best Paper Competition.     

ICP-MS法测定地球化学样品中As、Cr、Ge、V等18种微量痕量元素的研究

建立了测定地球化学样品中包括As、Cr、Ge、V等18种微量、痕量元素的ICP-MS方法。地化试样用HF-HNO3混酸分解后,以1 1 HNO3溶解干渣。由于制样不使用盐酸,避免了Cl对As、Cr、Ge、V的质谱干扰。用国家一级地球化学标准物质GBW 07309制备溶液优化仪器工作参数,并用于校准。方法测定限(6s)为:0.007~6.4μg/g,精密度(RSD%,n=12)为:29%~9.4%,经过国家一级地球化学标准物质的分析验证,结果与标准值吻合。方法已应用于国土资源调查的试样分析。     

Insect antifeedant properties of anthranoids from the genusVismia

Vismiones and ferruginins, representatives of a new class of lypophilic anthranoids from the genusVismia were found to inhibit feeding in larvae of species ofSpodoptera, Heliothis, and inLocusta migratoria.     

Ethanol and (−)-α-Pinene: Attractant Kairomones for Bark and Ambrosia Beetles in the Southeastern US

In 2002–2004, we examined the flight responses of 49 species of native and exotic bark and ambrosia beetles (Coleoptera: Scolytidae and Platypodidae) to traps baited with ethanol and/or (−)-α-pinene in the southeastern US. Eight field trials were conducted in mature pine stands in Alabama, Florida, Georgia, North Carolina, and South Carolina. Funnel traps baited with ethanol lures (release rate, about 0.6 g/day at 25–28°C) were attractive to ten species of ambrosia beetles (Ambrosiodmus tachygraphus, Anisandrus sayi, Dryoxylon onoharaensum, Monarthrum mali, Xyleborinus saxesenii, Xyleborus affinis, Xyleborus ferrugineus, Xylosandrus compactus, Xylosandrus crassiusculus, and Xylosandrus germanus) and two species of bark beetles (Cryptocarenus heveae and Hypothenemus sp.). Traps baited with (−)-α-pinene lures (release rate, 2–6 g/day at 25–28°C) were attractive to five bark beetle species (Dendroctonus terebrans, Hylastes porculus, Hylastes salebrosus, Hylastes tenuis, and Ips grandicollis) and one platypodid ambrosia beetle species (Myoplatypus flavicornis). Ethanol enhanced responses of some species (Xyleborus pubescens, H. porculus, H. salebrosus, H. tenuis, and Pityophthorus cariniceps) to traps baited with (−)-α-pinene in some locations. (−)-α-Pinene interrupted the response of some ambrosia beetle species to traps baited with ethanol, but only the response of D. onoharaensum was interrupted consistently at most locations. Of 23 species of ambrosia beetles captured in our field trials, nine were exotic and accounted for 70–97% of total catches of ambrosia beetles. Our results provide support for the continued use of separate traps baited with ethanol alone and ethanol with (−)-α-pinene to detect and monitor common bark and ambrosia beetles from the southeastern region of the US.