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91.
川中丘陵区一种新型小流域径流输沙模型的建立与应用   总被引:1,自引:0,他引:1  
径流输沙模型对定量评价水沙的输出响应具有重要的意义。本研究在已有研究成果的基础上,通过对四川盐亭县林山西沟小流域的径流、泥沙进行现场观测与分析,提出含沙量单位线的定义及其确定方法,建立了适应该小流域的径流输沙模型。并应用实测资料进行比较,表明模型的模拟结果可靠,模拟过程确定性系数达0.8以上,为川中丘陵区小流域径流输沙过程的预测预报提供了一个新方法。  相似文献   
92.
The proton nuclear magnetic resonance spectroscopy (1H-NMR), the synchronous fluorescence spectrometry (SFS) and the ruthenium ions catalyzed oxidation (RICO) method were used to determine the chemical structure of polyaromatic nucleus in Oman residue fractions. The results of 1H-NMR analyses showed that the average numbers of aromatic rings in the aromatics, resins and asphaltenes units were 3.2, 5.6 and 8.2, respectively. SFS was used to investigate the distribution of aromatic rings in residue fractions, the main distribution range of aromatic rings in aromatics, resins and asphaltenes were 3 4 rings, 3--5 rings and more than 5 rings, respectively. The aromatic network in residue fractions was oxidized to produce numerous carboxylic acids. The types and content of benzenepolycarboxylic acids, such as phthalic acid, benzenetricarboxylic acids, benzenetetracarboxylic acids, benzenepentacarboxylic acid and benzenehexacarboxylic acid disclosed the condensed types of aromatic nuclei in the core. The biphenyl fraction (BIPH), the cata-condensed fraction (CATA), the peri-condensed fraction (PERI) and the condensed index (BCI) were calculated based on the benzenepolycarboxylic acids formed. The results implied that there was less biphenyl type structures in all residue fractions. The aromatics fraction was almost composed of the cata-condensed type system, and the asphaltenes fraction was wholly composed of the peri-condensed type system, while in the resins fraction co-existed the two types, herein the peri-con- densed type was predominant over the cata-condensed type. Based on the analytical results obtained in the study, the components --aromatics, resins and asphaltenes -- were given the likely structural models.  相似文献   
93.
讨论了现代企业的过程观经及企业过程的构成,提出了企业生产经营全过程的作业管理思想,并对全过程作业管理的基本内容进行了探讨,分析了企业过程重组和优化的驱动因素、目标和实现途径,最后概述了全过程作业管理的支撑技术。  相似文献   
94.
Porous alumina films can be found in a wide variety of materials, including filters, thermal insulation components, dielectrics, biomedical and catalyst supports, coatings and adsorbents. Production methods for these films are as equally diverse as their applications. In this work, a hybrid process based upon chemical vapor deposition and gas-to-particle conversion is presented as an alternative technique for producing porous alumina films, with the main advantages of solvent-free, low substrate-temperature operation. In this process, nanoparticles were produced in the vapor phase by reaction of aluminum acetylacetonate in the presence of oxygen. Downstream of this reaction zone, these nanoparticles were collected via thermophoresis onto a cooled substrate, forming a porous film. Some deposited films were subjected to post-processing in the form of annealing in air. Fourier-transform infrared spectra and X-ray energy-dispersive spectroscopy analysis confirmed the production of alumina at processing temperatures above 973 K. X-Ray diffraction revealed that the films were amorphous. Film thickness, ranging from 30 to 250 μm, and the average deposition rate were determined from scanning electron microscopy results. From transmission electron microscopy, the average primary particle size was determined to be approximately 18 nm and the formation of nanoparticle aggregates was evident. Annealing of the films at temperatures ranging from 523 to 1173 K in the presence of air did not have an effect on particle size. The specific surface area of the powder composing the films ranged from 10 to 185 m2 g−1, as determined from nitrogen gas adsorption by the Brunauer–Emmett–Teller method.  相似文献   
95.
所开发的压水堆核燃料循环分析计算机经济程序包括12个子程序,代表着压水堆整个核燃料循环各种不同的工艺过程。本程序能算出压水堆核电站核燃料循环中燃料费用对发电成本的影响,给出各工艺过程对燃料成本的敏感度分析,并尽可能给出燃料循环中燃料材料及服务的价格数据.  相似文献   
96.
Objective: Guided by the extended parallel process model (EPPM), the objective was to assess control processes dominant in influenza behavior decisions. Design: Cross-sectional survey. Results: Response rate was 31% (n=968). Regarding influenza risk, 59% were in danger control. Those in fear control were more likely to report influenza infection (p=.000). In the nonvaccinated, those in fear control were more likely to indicate not knowing where to get the vaccine (p=.016) and that it was unavailable (p=.027), and those in danger control believed they did not need it (p=.023). Zero critical values were more likely to indicate that no health provider recommended the shot (p=.002). Conclusions: Most perceived efficacy to be stronger than threat related to influenza; according to the EPPM, they are aware of their risk but recognize their ability to avert it. For those in danger control, messages should focus on increasing perceptions of severity and susceptibility to positively affect behavior change. For those in fear control, messages should focus on efficacy only. With a critical value of zero, no threat is induced, and a high-threat/high-efficacy approach should be taken. (PsycINFO Database Record (c) 2010 APA, all rights reserved)  相似文献   
97.
介绍了二次盐水及离子膜电解工序的主要设备和流程,对二次盐水及离子膜电解工序运行中出现的问题进行了分析,并提出了解决措施。  相似文献   
98.
钢铁企业的氧气厂要深入了解本企业的用氧情况及周边市场的需要,据此确定拟新增空分装置的设计参数,选定最适宜的空分流程。探讨了空分流程选择时要考虑的几个方面。介绍了一种对空分装置的投资和长期运行费用之间进行经济性分析的定量计算公式,并得出了四点结论。  相似文献   
99.
欧阳伟 《江西冶金》2003,23(3):37-39
对自动化在选矿工业中应用的意义进行了论述。结合堆浸选矿的工艺特点,介绍了金矿选厂自动化系统的构成和自动化系统实现的基本功能。  相似文献   
100.
李长智  郭杰 《纺织器材》2003,30(5):46-49
论述了普通胶辊表面不处理的性能特点和存在问题,技术措施和合理工艺参数,提高了成纱条干水平,减少缠绕和磨损。  相似文献   
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