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1.
通过实例介绍了城镇地籍图及土地权属调查的基本要求、作业流程、街坊及宗地的划分、界址调查、权属争议、资料整理及提交等内容和方法,阐述了生产实践中总结的一些经验和体会。  相似文献   

2.
在目前埋地管道外防腐蚀工作中,“以涂层为主,阴极保护为辅”的联合防腐蚀技术已广泛应用于钢质埋地管道的防腐蚀系统中。这种技术将在防腐层缺陷等处的暴露金属表面上进行集中阴极保护,已确保整个防腐蚀系统的完整性。本文针对新青管道阴极保护调查过程中发现的问题,提出相应对策。  相似文献   

3.
热得快是一种浸入式液体加热产品,因其价格便宜、使用方便、操作简单,加热速度快而被广泛使用。但是由于产品质量和使用等原因,由其引发的火灾事故也屡有发生本文就热得快所引发的火灾予以阐述。  相似文献   

4.
本文阐述了项目中RTK应用的具体方法和操作技巧,通过与传统技术的比较等,突出了RTK的技术优点,并结合自己的实践体会,指出了RTK的技术缺点及改进的方法。  相似文献   

5.
火灾调查是消防工作的重要内容之一。本文在简要介绍国外发达国家火灾调查机制的基础上,从火灾调查目的、执行主体、业务标准等方面对比了中外火灾调查制度差异,并针对我国特点,提出了完善我国火灾调查制度的建议。  相似文献   

6.
杨磊 《标准科学》2013,(10):44-46
本文以广西为例,对我国皮革企业标准服务需求进行了实际调研,了解了皮革企业在生产、出口过程中在使用技术标准、合格评定、法律法规等方面遇到的问题,通过总结分析调研结果,提出了皮革行业标准化发展建议。  相似文献   

7.
农村土地调查目的与任务、农村土地调查的技术、土地权属调查资料与方法。  相似文献   

8.
农村土地调查目的与任务、农村土地调查的技术、土地权属调查资料与方法。  相似文献   

9.
伊嘉公路两侧桦树病害发生原因及相关分析   总被引:1,自引:0,他引:1  
桦木科(Betulaceae)桦木属植物的通称。全世界约有100种,主要分布于北温带,少数种类分布至寒带。中国产29种。主要病害有桦树心腐病、桦树白粉病、桦树锈病等,害虫有杨柳光叶甲和舞毒蛾等,但均不严重。近几年中国桦树病虫害在河北等地大面积发生,但因气象因子造成桦树生长势减弱并提早近一个多月落叶鲜有报道。伊春林区2009年发生大面积桦树严重发病,在伊春林区也是有记录的历史上第一次。本文通过对该病的发生现状及危害进行客观的论述,并对发病机理进行了探索。  相似文献   

10.
华鲁纳说:"学习的最好刺激乃是兴趣。"因此各国数学课程改革都把培养学生的数学兴趣作为数学老师的首要任务。通过对中学生数学兴趣的问卷调查,从学生的学习习惯,教材内容,教学方法等几个方面全面了解数学学习中影响中学生数学兴趣的因素,针对中学生数学兴趣的调查进行分析研究,激起学生学习兴趣,并从中得到乐趣。  相似文献   

11.
Distribution of heavy metals in Lakes Doirani and Kerkini, Northern Greece   总被引:2,自引:0,他引:2  
The distribution of heavy metals in two lakes of high ecological significance, Doirani and Kerkini, located in Northern Greece was studied. Eight metals (Cd, Cr, Cu, Fe, Mn, Ni, Pb and Zn) were determined in water, total suspended solids, fine and coarse sediments. Moreover, the modified BCR fractionation scheme was employed in sediments and suspended solids to determine soluble, oxidisable, reducible and residual fractions of metals. The Lake Doirani presents higher metal concentrations in aqueous phase than Lake Kerkini; Cd, Cu, Ni, Pb and Zn are above the chronic freshwater quality criteria for aquatic life. In both lakes, Fe and Mn are the most abundant elements in total suspended solids whereas Cd the less abundant. The Lake Kerkini exhibits higher concentrations of all the examined metals in sediments comparing to the Lake Doirani, however the concentrations are lower than the sediment quality guidelines. Cd in sediments is mainly in soluble fraction, Pb and Cu exhibit significant oxidisable fractions whereas, Cr and Fe associated mainly with residual fraction.  相似文献   

12.
Earlier advances in air separation and liquefaction include improvements in: overall product recovery, feed air purification, more efficient heat exchange, optimum plant control, gradual improvement in efficiency of compressors and expanders. More recent improvements include use of structured packing in distillation columns, molecular sieve adsorbents for air purification, computer simulation and control of plants, and increased machinery efficiency. Advances in fabrication and construction techniques are aimed at reducing capital costs. This paper reviews modern developments in air separation and liquefaction and attempts in this context to suggest features that might be expected to arise in the early part of the third millennium.  相似文献   

13.
Experimental investigation of oil retention in air conditioning systems   总被引:3,自引:1,他引:2  
In air conditioning and refrigeration systems a small amount of oil is carried with the refrigerant and is retained in the system components. Oil retention characteristics in the condenser, evaporator, liquid and suction lines were measured and are presented and discussed here. Refrigerants R22, R410A, and R134a with miscible and non-miscible lubricants were considered to investigate oil retention physics in the widest possible range of transport properties. A parametric analysis in the suction line showed that oil retention depends on the oil mass fraction, vapor refrigerant mass flux, mixture viscosity ratio and orientation of the pipe. In the suction line, an increase in mixture viscosity of about 55% caused a rise in oil retention in the range of 50%, depending on the oil mass fraction. Oil retention in the upward vertical suction line is about 50% higher than in the horizontal line at similar conditions.  相似文献   

14.
This Paper presents a comparative study of minces prepared from headed and gutted sardines and minces prepared from whole sardines, with a view to avoiding unnecessary product handling and improving yields. Certain additives (cryoprotectants and antioxidants) were blended into some of the mince lots in an attempt to extend their storage life, and in one of the lots the mince was washed prior to mixing. The minces were prepared by extrusion and the lots were fashioned into 4 cm thick 700 g blocks, frozen in a horizontal plate freezer until a core temperature of −20°C was attained, vacuum packed and stored at −20°C for 12 months. Proximate analysis, minerals analysis (Na,K,Mg,Ca,Fe and Cu) and yield measurements were carried out prior to freezing. Protein solubility, emulsifying capacity, cooking loss, K value, pH, TBA index, viable germ counts, entero and coliform bacteria, instrumental texture analysis and sensory analysis were periodically measured. The results obtained can be summarized as follows: the method of extrusion appears to be particularly well adapted to whole fish with regard to the avoidance of handling and improving yields. In relation to mineral content the only appreciable difference is a higher sodium content in minces made from whole fish (E lots) than in minces made from gutted and headed sardines (D lots), while in the washed lots there was an appreciable decreases in the amounts of Cu, Fe, Mg and K. Protein solubility stayed at higher levels in the E lots than in the D lots, though it was high in both types of mince at the end of storage: the use of protein cryoprotectants is advisable particularly in the washed D lot (DL) and in the E lots when storage of >6 monts is required. The emulsifying capacity, which was initially higher in the E lot than in the D lot, stabilized after the second month of storage. The effect of the protein cryoprotectants was to increase slightly the emulsifying capacity, which remained higher than in the control lots throughout the storage period, even in the DL lot, which the authors feel is important with regard to the use of these minces in sausage-type products. Cooking loss was initially higher in the D lots, but after the fourth month of storage it was the same for both types. The protein cryoprotectants reduced cooking loss and were more effective in the E lots. Due to fluctuations in K values obtained, the authors do not regard them as a reliable indicator of product quality. The pH was slightly more basic in the E lots than in the D lots, and pH increased in the additive-containing lots, especially in the washed mince preparation. The TBA index only showed significant differences between the D and E lots in the final test performed. The antioxidants appeared to be more effective in the E lots than in the D lots. Washing also delayed the onset of randicity, probably through the removal of fat and catalysts with the wash water. No synergistic effect was observed between the protein cryoprotectants and the antioxidants. The total initial count of micro-organisms was substantially higher in the E lots than in the D lots because of the intestinal content, though the levels equalized during storage and at no time exceeded allowable limits. Washing did not significantly decrease germ counts. The initial excessive amounts of enterobacteria in the E lots decreased during storage, whereas the level of caliform bacteria, on the other hand, remained constant. In the E lot without additives (ESS), however, Escherichia coli was detected prior to freezing but not in any of the subsequent analyses. In general, texture as determined by instrumental methods (hardness, firmness, elasticity, and cohesiveness) gave higher values for the D lots than for the E lots. Washing increased hardness and firmness while cryoprotectants reduced them. Cooking considerably hardened the samples in the case of the D lots but did not cause variations in the E minces. Hardness and firmness remained quite stable, although there was a slight increase in the cryoprotectants-free lots and washed minces. Elasticity tended to increase in the E lots during storage, and this effect was more pronounced in the cryoprotectants-free lots; cryoprotectants had the effect of decreasing elasticity and stabilizing it in the D lots, although they were higher in the D lots than in the E lots. Elasticity and cohesiveness remained constant in the washed mince. Cohesiveness increased in all the lots during storage, and the cryoprotectants exerted no effect on this parameter. In connection with the sensory analysis, a certain sweet taste was perceived in the cryoprotectants-containing D lots, slightly reducing the quality of the product, though it was not found unpleasant and was barely detectable in the E lots. The typical sardine flavoured lots by the washed mince reduced its acceptance, though this opens up a series of technological possibilities for it. A rancid taste was detectable in the ESS lot after five months in storage, in the E lot with protein antidenaturants (ESP) after eight months, and in the E lot that contained antioxidants (ESAO) and protein antidenaturants and antioxidants (ESA), in the last test carried out.  相似文献   

15.
16.
Hollow‐structured mesoporous materials (HMMs), as a kind of mesoporous material with unique morphology, have been of great interest in the past decade because of the subtle combination of the hollow architecture with the mesoporous nanostructure. Benefitting from the merits of low density, large void space, large specific surface area, and, especially, the good biocompatibility, HMMs present promising application prospects in various fields, such as adsorption and storage, confined catalysis when catalytically active species are incorporated in the core and/or shell, controlled drug release, targeted drug delivery, and simultaneous diagnosis and therapy of cancers when the surface and/or core of the HMMs are functionalized with functional ligands and/or nanoparticles, and so on. In this review, recent progress in the design, synthesis, functionalization, and applications of hollow mesoporous materials are discussed. Two main synthetic strategies, soft‐templating and hard‐templating routes, are broadly sorted and described in detail. Progress in the main application aspects of HMMs, such as adsorption and storage, catalysis, and biomedicine, are also discussed in detail in this article, in terms of the unique features of the combined large void space in the core and the mesoporous network in the shell. Functionalization of the core and pore/outer surfaces with functional organic groups and/or nanoparticles, and their performance, are summarized in this article. Finally, an outlook of their prospects and challenges in terms of their controlled synthesis and scaled application is presented.  相似文献   

17.
Sludge samples were collected from different treatment steps of Gaobeidian wastewater treatment plant (WWTP) of Beijing City, PR China, to investigate the distributions of total and chemical fractions of Fe, Mn, Ni, Cu, Zn, Cr, Pb, and Mo in different sludges. The highest total concentrations were found for Fe, Mn, Pb, and Mo in digested sludge (DS), Ni and Cr in thickened sludge (TS), Zn in dewatering sludge (DWS), and Cu in active sludge (AS). The lowest concentrations were observed in AS, except for Cu in TS. Significant differences of total metal concentration were observed between AS and TS (or DS), suggesting that sludge thickening and digesting treatments significantly influenced the total metal concentrations. Fe, Cu, Ni, Cr, Mo, and Pb distributed principally in the residual fraction in all sludges, while Zn and Mn presented in a highly available fraction. For same metal in different sludges, the portion of easily mobile fraction decreased significantly along the wastewater treatment process, and metals in AS presented in the highest available fraction. Organic matter contents, TN, and TP of sludges exhibited a significant positive correlation with the concentrations of exchangeable and reducible fraction of Pb, Mo, Cr, Cu, and Fe, while sludge pH demonstrated significant negative correlations with the concentrations of these metals.  相似文献   

18.
19.
Hepatitis C virus (HCV) infection is a significant health problem, as it can lead to chronic active hepatitis, liver cirrhosis, and hepatic carcinoma. Patients undergoing hemodialysis treatment are at increased risk of contracting HCV and other viral infections. This is primarily due to their impaired cellular immunity, underlying diseases, and blood exposure for a prolonged period. Transmission of viral hepatitis, and in particular HCV in dialysis units, has been showing a progressive increase worldwide, ranging between 5% in some western countries and up to 70% in some developing countries. The annual rate of HCV seroconversion in Saudi Arabia is 7% to 9%, while its prevalence is variable between 15% and 80%. This prevalence remained at almost 50% in recent years, despite the further increase in number of patients with end-stage renal disease and the expansion of dialysis services. The most prevalent genotypes in Saudi Arabia are genotype 4 followed by genotypes 1a and 1b, whereas genotypes 2a/2b, 3, 5, and 6 are rare. Genotypes 1 and 4 were associated with different histological grades of liver disease. Mixed infections with more than one genotype were observed in some studies. Isolation of dialysis machines and infected patients, together with strict application of infection-control policies and procedures and continuous education and training of nursing staff, remain the cornerstone in prevention and control of the spread of HCV infection in dialysis units. Interferon (INF)-alpha or pegylated INF, alone or in combination with ribavirin, have shown great promise in the treatment of chronic HCV in dialysis patients.  相似文献   

20.
Some recent developments in the areas of measurement, prediction, and correlation of thermophysical properties and phase behavior are reviewed. However. important problems remain, and some of these are not being addressed. Here a number of thermophysical properties problem areas are identified based on the prejudices of the author and a small survey of friends and colleagues in industry and academia. Many of the problems arise as result of changes in industrial emphasis, for example, from chemicals to materials and pharmaceuticals, changes in federal or local regulations permitting lower air and water emissions, changes in technology, and an interest in determining the fate of chemicals in the environment. Some of the research needs, both experimental and theoretical. to deal with these problems are discussed.  相似文献   

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