工程竣工造价结算审核策略探究

工程竣工造价结算审核是工程造价结算的必要途径,通过工程竣工造价的结算可以科学合理的掌握整个工程的造价,提升建筑公司的核心竞争力,也能节约成本。目前我国工程竣工造价结算审核还处于发展阶段,有很多还待完善的地方．．本文中笔者将从理论和实践两个方面,对工程施工阶段的造价预算特点,以及工程竣工造价结算审核的特点的分析,对工程竣工造价结算审核策略提出一些建议和意见,希望对我国的工程竣工造价结算审核的健康发展有所帮助。     

Preparation of copper arsenite and its application in purification of copper electrolyte

The preparation of copper arsenite with arsenic trioxide was presented and its application in the purification of copper electrolyte was proposed. The variables of n（OH^-）/n（As）, n（Cu）/n（As）, NaOH concentration, reaction temperature and pH value have some effects on the yield of copper arsenite. The optimum conditions of preparing copper arsenite are that the molar ratio of alkali to arsenic is 2：1, NaOH concentration is 1 mol/L, the molar ratio of copper to arsenic is 2：1, pH value is 6.0 and reaction temperature is 20℃. The yield of copper arsenite is as high as 98.65% under optimum conditions and the molar ratio of Cu to As in the product is about 5：4. The results of the purification experiments show that the removal rate of antimony and bismuth is 53.85% and 53.33% respectively after 20g/L copper arsenite is added. The purification of copper electrolyte with copper arsenite has the advantages of simple technique, good purification performance and low cost.     

湖泊水质卫星遥感方法及其应用

通过系统性的常规水质采样分析与水面光谱测量外场同步试验,建立了由FY-1C多通道扫描辐射计、Landsat卫星TM和Seastar卫星SeaWiFS等在轨卫星多通道遥感器以及一组设想的遥感通道遥感反演叶绿素a浓度和总悬浮物浓度的优化通道组合模型,提出了一种利用水面上标准反射板的反射光谱和遥感图像本身确定大气透过率和反射率从而实现大气校正的水质指标卫星遥感反演方法．所建立的模型和方法被用于遥感解译我国典型富营养化湖泊太湖和滇池从80至90年代的富营养化程度及其分布状况随年份的变化．本项研究为进一步开展湖泊水质业务化卫星监测打下了基础．     

精密电能表检定装置扩展不确定度分析

文章介绍了三相电能表检定装置扩展不确定度的分析与计算方法，指出：误差分析的关键是如何确定扩展不确定度。     

制冷过程的断水及超压报警

制冷过程中冷却水断水及氨压机出口压力超压，会造成制冷设备全线停车的重大事故。采用测量冷冻盐水泵出口压力间接测量断水并报警及直接测量氨压机出口压力超压并报警的方案，简单可行，应用效果也好。     

头台油田套损井压裂工艺技术试验

为了提高头台油田的开发效果，完善注采系统，分析研究了套损井在压裂工作中存在的难点及施工的风险性，针对M60-92及M62-90套损井的情况，通过采取在压裂措施前进行大修改造、优化压裂工艺设计、精心组织压裂施工现场等措施，修复了这两口套损井且压裂成功，为以后的修井工程开辟了新的思路。     

Novel technology of purification of copper electrolyte

The effects of arsenic with different valence states on the purification of copper electrolyte were studied and a novel technology of purification of copper electrolyte by copper arsenite was proposed. The results show that the purification performance of As（Ⅲ） compounds is better than that of As（Ⅴ） compounds. The purification technology by copper arsenite has the advantages of simple operation, high purification performance and low cost in comparison with other technologies and its appropriate purification conditions are that copper arsenite concentration is 18 g/L, reaction temperature is 65 ℃ and reaction time is 8 h. The removal rates of Sb and Bi are 53.22% and 58.67% respectively under these conditions. The purification principle show that a kind of yellow precipitate mainly composed of arsenic, antimony （ Ⅴ ）, bismuth and oxygen forms in electrolyte after copper arsenite is added, and consequently antimony and bismuth are removed from electrolyte.     

Industrial experiment of copper electrolyte purification by copper arsenite

Copper electrolyte was purified by copper arsenite that was prepared with AS2O3. And electrolysis experiments of purified electrolyte were carried out at 235 and 305 A/m^2, respectively. The results show that the yield of copper arsenite is up to 98.64% when the molar ratio of Cu to As is 1.5 in the preparation of copper arsenite. The removal rates of Sb and Bi reach 74.11% and 65.60% respectively after copper arsenite is added in electrolyte. The concentrations of As, Sb and Bi in electrolyte nearly remain constant during electrolysis of 13 d. The appearances of cathode copper obtained at 235 and 305 A/m^2 are slippery and even, and the qualification rate is 100% according to the Chinese standard of high-pure cathode copper（GB/T467-97）.