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Numerical study of internal flow field and flow passage improvement of an inlet particle separator

Florian PAOLI, Tong WANG

《能源前沿（英文）》 2011年第5卷第4期页码 386-397 doi: 10.1007/s11708-011-0156-8

摘要： By performing gas flow field numerical simulations for several inlet Reynolds numbers (from 2 × 10 to 9 × 10 ) and byflow ratios (from 10% to 20%), the present study has proposed to improve the flow passage of an inlet particle separator. An adjacent objective of the study is to lower pressure losses of the inlet particle separator (IPS). No particle has been included in the gas flow for a -epsilon turbulence model. The velocity distribution in different sections and the pressure coefficient along the duct have been analyzed, which indicates that there exist important low-velocity regions and vortices in the separation area. Therefore, the profile of streamlines along the original passage has been considered. This profile illustrated a vacuum region in the same area. All investigations suggest that the separation area is the most critical one for fulfilling the objective on pressure losses limitation. Then the flow passage improvement method has focused on the separation area. An improved shape has been designed in order to suit smoothly to the streamlines in this region. Similar numerical studies as those for the original shape have been conducted on this improved shape, confirming some considerable enhancements compared with the original shape. The significant vortices which appear in the original shape reduce in amount and size. Besides, pressure losses are greatly decreased in both outlets (up to 30% for high Reynolds number) and the flow is uniform at the main outlet. Subsequent engineering surveys could rely on expressions obtained for in both outlets which extend the pressure losses for a wide range of inlet Reynolds numbers. As a result, the numerical calculations demonstrate that the flow passage improvement method applied in this study has succeeded in designing a shape which enhances the flow behavior.

关键词： streamlines pressure losses flow passage improvement inlet particle separator (IPS)

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Test investigation on hydraulic losses in the discharge passage of an axial-flow pump

QIU Baoyun, CAO Haihong, JIANG Wei, GAO Zhaohui, WANG Fei

《机械工程前沿（英文）》 2007年第2卷第1期页码 50-56 doi: 10.1007/s11465-007-0008-8

摘要： In a discharge passage with a guide blade discharge circulation and secondary flow because of bend pipe, the flow in a 1-channel discharge passage of an axial flow pump is a complicated spiral flow. For a 2-channel passage, the discharge in the left channel is bigger than that in the right, and the passage hydraulic losses are abnormal. In this study, the section current energy of the passage is accurately measured and determined with a 5-hole probe. The hydraulic loss characteristics are determined and analyzed. The methods deducing the hydraulic losses are investigated. The results indicate that the passage hydraulic losses are not proportional to the flow discharge. Compared with a circular pipe, the hydraulic losses of a divergent discharge passage are smaller and the pump assembly efficiency is 10% 30% higher. As for the 1-channel passage, the axial-flow pump outlet circulation is usually too big; the passage hydraulic losses are also big, but a small circulation can slightly reduce hydraulic losses. As for the 2-channel passage, discharges in the two channels are not equal and the hydraulic losses increase. The outlet guide blade with a small discharge circulation or without circulation could reduce discharge passage hydraulic losses and increase pump assembly efficiency by 6% 11%.

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接触冲刷发展过程模拟研究

陈建生,刘建刚,焦月红

《中国工程科学》 2003年第5卷第7期页码 33-39

摘要：

为研究堤基接触冲刷渗透破坏机理，对粘土层与砂砾石层之间各种成因的粗糙面或缝隙渗透性用光滑裂隙的渗透性代替，地层整体的渗透性由裂隙、砾石层和砂砾石层的渗透性决定，以细砂的起动速度为判别标准，通过分时段的稳定流计算，接触面附近的细砂从出渗口开始流出，出渗口附近的渗透系数首先增大，然后逐步向内部发展，以垂直河岸方向的发展最为迅速，甚至形成贯通性集中渗漏通道。

关键词：接触冲刷起动速度流网集中渗漏通道

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Exploring differentiated improvement strategies of cultivated land quality in China

《农业科学与工程前沿（英文）》 doi: 10.15302/J-FASE-2023523

摘要：

● Cultivated land quality can be considered in four dimensions: suitability, contiguity, resistance, and ecological stress.

关键词： China cultivated land quality differentiated improvement food security

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Research progress on genetic improvement of

Chuanping YANG

《农业科学与工程前沿（英文）》 2017年第4卷第4期页码 391-401 doi: 10.15302/J-FASE-2017183

摘要： Suk. is one of the most widely distributed species of , the fourth most valuable timber species in north-eastern China and also a common tree species for landscaping. Over the past 30 years, effective progress has been made in genetic improvement and molecular breeding of . There has been extensive research on breeding techniques, including the collection and conservation of germplasm resources, provenance trials, intensive breeding techniques, crossbreeding and asexual propagation techniques, ploidy breeding and mutation breeding technology, genome sequencing, gene cloning, transgenic and molecular mechanisms of wood formation. A germplasm resource collection has been established by collecting different provenances, and full-sib and half-sib families. In addition, the geographic variation patterns of provenances have been revealed, and the provenance division and superior provenance selections made. flowering and seeding have been improved through intensive breeding techniques. Interspecific hybridization, intraspecific hybridization and parallel crosses were made using fine parents, and intensive seed orchards have been established. Systems of asexual propagation, including cuttings, grafting and tissue culture have been established. A tetraploid was successfully constructed and a triploid seed orchard established. The growth, wood property and resistance genes of have been cloned. An efficient transgenic system mediated by was established, and genes encoding insect resistance, drought resistance and salt tolerance, lignin synthesis, flowering, hormone transport and balance obtained. molecular markers were developed and the high density genetic map constructed. All this research has provided a model and data for the foundation of forest genetic improvement and applied research.

关键词： Betula platyphylla genetic improvement molecular breeding seed orchard

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A review of systematic evaluation and improvement in the big data environment

Feng YANG, Manman WANG

《工程管理前沿（英文）》 2020年第7卷第1期页码 27-46 doi: 10.1007/s42524-020-0092-6

摘要： The era of big data brings unprecedented opportunities and challenges to management research. As one of the important functions of management decision-making, evaluation has been given more functions and application space. Exploring the applicable evaluation methods in the big data environment has become an important subject of research. The purpose of this paper is to provide an overview and discussion of systematic evaluation and improvement in the big data environment. We first review the evaluation methods based on the main analytic techniques of big data such as data mining, statistical methods, optimization and simulation, and deep learning. Focused on the characteristics of big data (association feature, data loss, data noise, and visualization), the relevant evaluation methods are given. Furthermore, we explore the systematic improvement studies and application fields. Finally, we analyze the new application areas of evaluation methods and give the future directions of evaluation method research in a big data environment from six aspects. We hope our research could provide meaningful insights for subsequent research.

关键词： big data evaluation methods systematic improvement big data analytic techniques data mining

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Improvement potential of today’s WEEE recycling performance: The case of LCD TVs in Belgium

Paul Vanegas, Jef R. Peeters, Dirk Cattrysse, Wim Dewulf, Joost R. Duflou

《环境科学与工程前沿（英文）》 2017年第11卷第5期 doi: 10.1007/s11783-017-1000-0

摘要： Waste of electrical and electronic equipment (WEEE) constitutes one of the most relevant waste streams because of the quantity and presence of valuable materials. However, there is limited knowledge on the resource potential of urban mining WEEE, as data on material composition, and the efficiency of current recycling treatments are still scarce. In this article, an evaluation of the recycling performance at a national level for one of the fastest growing e-waste streams: LCD TVs is carried out through the following four steps. Firstly, material characterisation is performed by means of sampling of the waste stream. Secondly, a material flow analysis is conducted by evaluating the separation performance of a recycling plant in Belgium. Thirdly, the recovered economic value and avoided environmental impact (EI) of the analysed recycling system is assessed. Finally, the potential of urban mining for Belgium is forecasted. The analysis shows that while recycling performance for ferrous metals and aluminium are relatively high; there is substantial room to better close the material loops for precious metals (PM) and plastics. PMs and plastics account for 66 % of the economic value in LCD TVs and 57% of the EI. With the current, commonly applied recycling technology only one-third of the PM and housing plastics are recycled; meaning that for these materials, at a national level for Belgium, there is a potential for improvement that represents 3.3 million euros in 2016 and 6.8 million euros in 2025.

关键词： Recycling Waste of electrical and electronic equipment (WEEE) Material flow analysis LCD TVs Precious metals Plastics

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Quality and efficiency improvement technology for five megawatt offshore wind turbines and its application

Huali HAN

《工程管理前沿（英文）》 2020年第7卷第4期页码 618-621 doi: 10.1007/s42524-020-0142-0

关键词： renewable energy megawatt offshore wind turbine technology-driven quality improvement

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中国石油油气战略通道建设与管理创新实践

黄维和

《中国工程科学》 2012年第14卷第12期页码 19-24

摘要：

油气管道是国民经济发展的能源大动脉。随着我国油气对外依存度的逐年提高，打通油气战略通道、保障能源供给成为当务之急。在陆上油气战略通道建设过程中，通过“1+N”协同式自主创新，形成了管道设计、施工、装备国产化及易凝高粘原油输送等关键技术，建成了目前总长6×104 km、输送油品1.7×108 t、输送天然气1.4×1011 m³的大型油气管网。在大型管网运行管理过程中，通过建立e-SAME安全一致性系统，形成了运行管理组织机构、资产完整性管理、市场保障和应急维护等子系统，确保了企业安全目标地实现。

关键词：管道战略通道建设管理

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Embryo-mediated genome editing for accelerated genetic improvement of livestock

Zachariah MCLEAN, Björn OBACK, Götz LAIBLE

《农业科学与工程前沿（英文）》 2020年第7卷第2期页码 148-160 doi: 10.15302/J-FASE-2019305

摘要：

Selecting beneficial DNA variants is the main goal of animal breeding. However, this process is inherently inefficient because each animal only carries a fraction of all desirable variants. Genome editing technology with its ability to directly introduce beneficial sequence variants offers new opportunities to modernize animal breeding by overcoming this biological limitation and accelerating genetic gains. To realize rapid genetic gain, precise edits need to be introduced into genomically-selected embryos, which minimizes the genetic lag. However, embryo-mediated precision editing by homology-directed repair (HDR) mechanisms is currently an inefficient process that often produces mosaic embryos and greatly limits the numbers of available edited embryos. This review provides a summary of genome editing in bovine embryos and proposes an embryo-mediated accelerated breeding scheme that overcomes the present efficiency limitations of HDR editing in bovine embryos. It integrates embryo-based genomic selection with precise multi-editing and uses embryonic cloning with elite edited blastomeres or embryonic pluripotent stem cells to resolve mosaicism, enable multiplex editing and multiply rare elite genotypes. Such a breeding strategy would enable a more targeted, accelerated approach for livestock improvement that allows stacking of beneficial variants, even including novel traits from outside the breeding population, in the most recent elite genetic background, essentially within a single generation.

关键词： animal breeding cattle cloning CRISPR/Cas9 cytoplasmic injection embryo genome editing germline chimaeras HDR livestock improvement TALENs

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Management System and Education Model in Developed Countries for Engineering Management Major Education Improvement

Jian-ya Jiang,Yang-wei Rao

《工程管理前沿（英文）》 2014年第1卷第4期页码 406-409 doi: 10.15302/J-FEM-2014049

摘要： Different developed countries have differences in regulations for engineering management systems. The related education modes and their curriculum arrangement in universities in the US, UK, and Germany show their specializations. Through comparative research into engineering management systems and professional education modes between China and these developed countries, the paper proposes suggestions for improving the education of engineering management majors in China, which could speed up development of Chinese engineering general contracting enterprises and engineering project management enterprises.

关键词： engineering management system education mode comparative research training improvement

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长江越江通道工程应实行桥隧并举

钱七虎,何益寿

《中国工程科学》 2001年第3卷第5期页码 32-34

摘要：

长江越江交通通道工程对我国21世纪经济的稳定发展作用巨大，因此在越江交通通道工程方案的选择上不能唯桥是举，而要因地制宜和恰到好处地发挥桥梁和水下隧道各自的优势，总体上实行桥隧并举。

关键词：长江越江交通通道工程桥梁水下隧道

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Genetic improvement of wheat grain quality at CIMMYT

Carlos GUZMÁN, Karim AMMAR, Velu GOVINDAN, Ravi SINGH

《农业科学与工程前沿（英文）》 2019年第6卷第3期页码 265-272 doi: 10.15302/J-FASE-2019260

摘要：

The International Maize and Wheat Improvement Center (CIMMYT) is the global leader in publicly-funded maize and wheat research and in farming systems based on these crops. CIMMYT leads the Global Wheat Program (GWP), which includes some of the largest wheat breeding programs in the world. The GWP has been successful in developing wheat germplasm that is used extensively worldwide. Wheat quality improvement is a central component of all the breeding efforts at CIMMYT and the Wheat Chemistry and Quality Laboratory represents an integral part of the breeding programs. Wheat quality is addressed at CIMMYT over the full range of this very wide and variable concept with milling, processing, end-use and nutritional quality targeted. Wheat progenitors and advanced lines developed by the breeders are assessed for diverse quality attributes, with the aim of identifying those that fulfill the requirements in terms of milling, processing, end-use and nutritional quality in different target regions. Significant research is conducted to make more efficient the integration of wheat quality traits in the breeding programs. The main topics being addressed are (1) methodologies to analyze grain quality traits, (2) genetic control and environmental effects on quality traits, (3) characterization of genetic resources for quality improvement, and (4) diversifying grain properties for novel uses.

关键词： biofortification breeding grain quality wheat

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Molecular regulation and genetic improvement of seed oil content in

Wei HUA,Jing LIU,Hanzhong WANG

《农业科学与工程前沿（英文）》 2016年第3卷第3期页码 186-194 doi: 10.15302/J-FASE-2016107

摘要： As an important oil crop and a potential bioenergy crop, L. is becoming a model plant for basic research on seed lipid biosynthesis as well as seed oil content, which has always been the key breeding objective. In this review, we present current progress in understanding of the regulation of oil content in , including genetics, biosynthesis pathway, transcriptional regulation, maternal effects and QTL analysis. Furthermore, the history of breeding for high oil content in is summarized and the progress in breeding ultra-high oil content lines is described. Finally, prospects for breeding high oil content cultivars are outlined.

关键词： breeding maternal effects oilseed rape QTL

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Air quality improvement in Los Angeles—Perspectives for developing cities

David D. Parrish,Jin Xu,Bart Croes,Min Shao

《环境科学与工程前沿（英文）》 2016年第10卷第5期 doi: 10.1007/s11783-016-0859-5

摘要： Air quality improvement in Los Angeles can inform air quality policies in developing cities. Emission control efforts, their results, costs and health benefits are briefly summarized. Today's developing cities face new challenges including regional pollution. Air quality issues in Beijing are briefly compared and contrasted with Los Angeles. Opportunities for co-benefits for climate and air quality improvement are identified. Air quality improvement in Los Angeles, California is reviewed with an emphasis on aspects that may inform air quality policy formulation in developing cities. In the mid-twentieth century the air quality in Los Angeles was degraded to an extent comparable to the worst found in developing cities today; ozone exceeded 600 ppb and annual average particulate matter <10 mm reached ~150 mg·m . Today's air quality is much better due to very effective emission controls; e.g., modern automobiles emit about 1% of the hydrocarbons and carbon monoxide emitted by vehicles of 50 years ago. An overview is given of the emission control efforts in Los Angeles and their impact on ambient concentrations of primary and secondary pollutants; the costs and health benefits of these controls are briefly summarized. Today's developing cities have new challenges that are discussed: the effects of regional pollution transport are much greater in countries with very high population densities; often very large current populations must be supplied with goods and services even while economic development and air quality concerns are addressed; and many of currently developing cities are located in or close to the tropics where photochemical processing of pollution is expected to be more rapid than at higher latitudes. The air quality issues of Beijing are briefly compared and contrasted with those of Los Angeles, and the opportunities for co-benefits for climate and air quality improvement are pointed out.

关键词： Air pollution Ozone Particulate matter Control technology