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81.
近年来,“自动矿物学”(或“定量矿物学”)的概念和相关技术得到了显著的发展和广泛的应用,使矿物学研究,尤其是工艺矿物学研究从人工测试走向自动化测试、从定性研究走向定量研究。本文评述了自动矿物学的技术进展与应用,主要包括:①矿物分析技术发展阶段;②自动矿物学技术国际研究进展与国内研究现状;③自动矿物学的应用领域及发展趋势。在此基础上,总结了基于扫描电镜的自动矿物学技术的基本原理以及选矿产品环氧树脂抛光片制备过程中需要注意的一些问题。以期为固体地球科学研究和矿产资源开发利用过程中遇到的一些瓶颈问题提供新的研究途径和新的思路。  相似文献   
82.
Hybrid electric vehicles (HEVs) with low fuel consumption, low emissions, and long driving range are the ideal transition models between conventional fuel vehicles and pure electric vehicles. The growing demand for increased vehicle efficiency has motivated the introduction of waste heat recovery (WHR) technology in the automotive industry, with the organic Rankine cycle (ORC) as the most promising measure for recycling waste energy. Currently, only a few studies have been conducted to couple HEV and WHR systems. These studies have mainly focused on the hybrid powertrain control strategy, but lack quantitative methods to comprehensively analyze the fuel-saving potential due to the WHR system. In this study, an HEV-WHR integrated system that includes a mechanism-based dynamic model of ORC and a hybrid diesel-electric truck model is established. Further, a quantitative evaluation method that simultaneously considers the negative integrated effects (increased vehicle weight and increased exhaust back pressure) and the positive impact values of the engine, motor, and WHR system on the fuel-saving potential is proposed. Finally, the influence of two environmental factors (wind speed and ambient temperature) on the fuel-saving performance is analyzed. The results reveal that under the standard highway driving cycle (HWY), the negative integrated effects reduce the ideal fuel-saving potential of the HEV-WHR system from 6.10% to 5.42%. However, the optimized performances of the engine, motor, and WHR system improve the fuel-saving rate by 0.39%, 1.81%, and 3.22%, respectively. The results also indicate that the fuel-saving potential increases from 1.62% to 8.60% with increasing wind speed and decreases from 6.70% to 4.25% with increasing ambient temperature.  相似文献   
83.
This paper provides an overview of regional science research in the Netherlands since the 1960s. It adopts a contextual thematic approach in identifying and interpreting regional science research topics, practices and methodologies, inspired by Toynbee's challenge and response concept. It argues that place-based, cultural and historical conditions in the Netherlands have prompted a pragmatic and evidence-based scientific approach, in which in particular an innovative quantitative orientation accompanied by a methodological heterogeneity has given Dutch regional science a high international profile. Over the past decades, numerous regional scientists in the country have contributed to this achievement, too many to be mentioned in this overview. This paper has its limitations and offers mainly thematic examples of original—often quantitative—research undertaken by various Dutch regional scientists, that make a difference compared to general approaches in Europe and world-wide. From our concise review we conclude that – despite the small size of the country – the challenge and creative response model of Dutch regional science has been rather successful.  相似文献   
84.
In this article, novel methods and ideas are introduced, which altogether lead to an accurate model of power transformer windings. First, by the determination of non-dominant (hidden) resonances from frequency-response tests, a ladder model is proposed. Next, it is improved by assigning different values for similar elements of each section of the model. The parameters are obtained by minimizing the error function via a genetic algorithm. Sensitivity analysis is then applied to the obtained model to achieve further examinations and tests. Measurements have been driven from the windings of a 20/0.4-kV, 1600-kVA transformer. Modeling, methodologies, and sensitivity analysis in this article can be very useful for future research aiming to find internal faults of the transformer with the frequency response analysis.  相似文献   
85.
We will consider a convex subset of a metric linear space and a certain group of actions G on this set, that allow us to define the notion of Haar zero measure on sets that have zero Haar measure for the translation (by adding) invariant HSY prevalence theory. In this way, we will be able to define the meaning of G-prevalent set according to the pioneering work of Christensen. Our setting considers problems which take into account the convex structure and this is quite different from the previous results on prevalence which consider basically the linear additive structure. In this setting, we will show a kind of quantitative Kupka–Smale theorem, and also we generalize a result about rotation numbers which was first considered by J.-C. Yoccoz (and, also by M. Tsujii). Among other things we present an estimation of the amount of hyperbolicity in a setting that we believe was not considered before.  相似文献   
86.
为分析不同沉积与成岩作用改造下致密砂岩储层的孔喉类型及其参数差异,利用物性、铸体薄片、扫描电镜、恒速压汞、图像粒度与X衍射实验结果,对比了鄂尔多斯盆地合水地区延长组长8储层和薛岔地区延长组长6储层的孔喉类型,定量评价了孔喉参数,揭示了形成原因。结果表明,合水地区长8储层孔隙更为发育,粒间孔、溶蚀孔、晶间孔和微孔、弱压实成因缩颈状喉道和溶蚀成因、粘土胶结成因管束状喉道含量高;薛岔地区长6储层的孔隙类型少且发育程度较差,压实成因片状、弯片状喉道含量高。两个区块的孔隙参数差异小,喉道参数差异大,前者大喉道更为发育,喉道差异大,孔喉比大,对渗透率起贡献的喉道分布范围更宽。相同渗透率条件下,前者的平均喉道半径、主流喉道半径和孔喉比大于后者。沉积水动力条件、粒度、碎屑组分、填隙物、成岩作用类型及其改造程度是两个研究区孔隙发育程度不同、喉道类型差异和孔喉参数表现出不同特征的主要原因。  相似文献   
87.
88.
This article reports the findings of a quantitative study on the relationship between various project performance outcomes and the use of Building Information Modeling (BIM), within the commercial construction industry. The literature review identified inconsistent results among prior qualitative and quantitative work concerning the relationships of key project performance measures and BIM use. Data on 13 variables from 93 completed construction projects were collected and examined through a causal comparative research design. Projects that used BIM (in design or construction) were not found to experience significant performance outcomes when controlling for the contribution of other independent variables and covariates at the 95% confidence level (CL). At the lower 90% CL, however, projects using BIM in construction experienced significantly higher levels of schedule growth than projects that did not use BIM in construction. Recommendations are made for training of construction management staff as a step to avoid unwanted schedule growth associated with BIM use during construction. This study is one of a very small group of rigorous quantitative analyses of BIM project performance outcomes conducted to date; additionally, it is the only study that has analyzed BIM in a multivariate context that controlled for the contribution of other project variables not directly related to BIM use.  相似文献   
89.
90.
Reliable prediction of the long-term behavior of environmental systems such as Municipal Solid Waste (MSW) landfills is challenging. While many driving forces influence this behavior, characterization of them is limited by measurement techniques. Therefore, a model structure for reliable prediction needs to optimally combine all measured information with suitable mechanistic information from literature. How to get such an optimal model structure? This study presents a toolbox to find and build the model structure that describes an environmental system as close as possible. The toolbox combines environmental frameworks to include all suitable mechanistic information; it fully couples kinetic and equilibrium reactions and contains multiple resources to obtain biogeochemical parameters. Several possible optimal model structures are quickly built and evaluated with objective statistical performance criteria obtained via Bayesian inference. By applying the novel methodology, we select the best model structure for anaerobic digestion of MSW in full scale landfills.  相似文献   
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