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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    

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    

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    

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    

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    

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    

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    

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    

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    

FOR USE IN AGROECOSYSTEM IMPROVEMENT IN SEMI-ARID AREAS WITH A FOCUS ON CENTRAL ANATOLIA, TURKEY

《农业科学与工程前沿(英文)》 2021年 第8卷 第4期   页码 568-582 doi: 10.15302/J-FASE -2019270

摘要:

Agroecosystems in water-limited contexts— Mediterranean, semi-arid and arid climatic zones—are too frequently degraded systems that will not provide the needed ecosystem services to ensure a future of sustainable agricultural production. The processes that have created this situation continue and are being accelerated by anthropogenic climate change. Increasing arboreal vegetation in these areas through agroforestry is an important strategy to conserve and improve their agroecosystems. Actinorhizal trees and shrubs in the Casurinaceae have a unique set of adaptations for heat and water stress, and/or infertile to hostile soils. Central Anatolia, Turkey is particularly at risk of increasing aridity and further degradation. Therefore, species of Allocasuarina and Casuarina have been evaluated for their potential use in agroecosystem improvement in semi-arid areas with a focus on Central Anatolia. Based on a semiquantitative environmental tolerance index and reported plant stature, eight species were identified as being of high (Averticillata and Cpauper) to moderate (AacutivalvisAdecaisneanaAdielsianaAhuegelianaCcristata and Cobesa) priority for assessment, with none of these species having been adequately evaluated for agroforestry deployment in semi-arid agroecosystems in any context.

 

关键词: actinorrhizal trees / agroforestry / climate change / ecosystem restoration    

Ductility improvement of GFRP-RC beams using precast confined concrete block in compression zone

《结构与土木工程前沿(英文)》 doi: 10.1007/s11709-023-0968-8

摘要: Fiber-reinforced polymers (FRPs) have received considerable research attention because of their high strength, corrosion resistance, and low weight. However, owing to the lack of ductility in this material and the quasi-brittle behavior of concrete, FRP-reinforced concrete (FRP-RC) beams, even with flexural failure, do not fail in a ductile manner. Because the limited deformation capacity of FRP-RC beams depends on the ductility of their compression zones, the present study proposes using a precast confined concrete block (PCCB) in the compression zone to improve the ductility of the beams. A control beam and four beams with different PCCBs were cast and tested under four-point bending conditions. The control beam failed due to shear, and the PCCBs exhibited different confinements and perforations. The goal was to find an appropriate PCCB for use in the compression zone of the beams, which not only improved the ductility but also changed the failure mode of the beams from shear to flexural. Among the employed blocks, a ductile PCCB with low equivalent compressive strength increased the ductility ratio of the beam to twice that of the control beam. The beam failed in pure flexure with considerable deformation capacity and without significant stiffness reduction.

关键词: ductility     four-point bending test     glass fiber-reinforced polymer     precast confined concrete block    

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)    

Performance improvement of a pulse tube cryocooler with a single compressor through cascade utilization

Xuming LIU, Xiafan XU, Biao YANG, Xiaotong XI, Liubiao CHEN, Junjie WANG, Yuan ZHOU

《能源前沿(英文)》 2021年 第15卷 第2期   页码 345-357 doi: 10.1007/s11708-020-0708-x

摘要: The high-frequency pulse tube cryocooler (HPTC) has been attracting increasing and widespread attention in the field of cryogenic technology because of its compact structure, low vibration, and reliable operation. The gas-coupled HPTC, driven by a single compressor, is currently the simplest and most compact structure. For HPTCs operating below 20 K, in order to obtain the mW cooling capacity, hundreds or even thousands of watts of electrical power are consumed, where radiation heat leakage accounts for a large proportion of their cooling capacity. In this paper, based on SAGE10, a HPTC heat radiation calculation model was first established to study the effects of radiation heat leakage on apparent performance parameters (such as temperature and cooling capacity), and internal parameters (such as enthalpy flow and gas distribution) of the gas-coupled HPTC. An active thermal insulation method of cascade utilization of the cold energy of the system was proposed for the gas-coupled HPTC. Numerical simulations indicate that the reduction of external radiation heat leakage cannot only directly increase the net cooling power, but also decrease the internal gross losses and increase the mass and acoustic power in the lower-temperature section, which further enhances the refrigeration performance. The numerical calculation results were verified by experiments, and the test results showed that the no-load temperature of the developed cryocooler prototype decreased from 15.1 K to 6.4 K, and the relative Carnot efficiency at 15.5 K increased from 0.029% to 0.996% when substituting the proposed active method for the traditional passive method with multi-layer thermal insulation materials.

关键词: radiation heat leakage     active thermal insulation     cascade utilization     cold energy     performance improvement     cryocooler    

On the improvement design of dynamic characteristics for the roller follower of a variable-speed plate

Hui Ching FAN, Hong Sen YAN

《机械工程前沿(英文)》 2012年 第7卷 第1期   页码 5-15 doi: 10.1007/s11465-012-0310-y

摘要:

Without modifying the cam contour, a cam mechanism with a variable input speed trajectory offers an alternative solution to flexibly achieve kinematic and dynamic characteristics, and then decrease the follower’s residual vibration. Firstly, the speed trajectory of cam is derived by employing Bezier curve, and motion continuity conditions are investigated. Then the motion characteristics between the plate cam and its roller follower are derived. To analyze the residual vibration, a single degree of freedom dynamic model of the elastic cam-follower system is introduced. Based on the motion equation derived from the dynamic model, the residual vibration of the follower is yielded. The design procedure to improve the kinematic and dynamic motion characteristics is presented and two design examples with discussions are provided. Finally, the simulations of the kinematic and dynamic models by ADAMS are carried out and verified that the design models as well as the performances of the mechanism are feasible.

关键词: cam mechanism     variable input speed     kinematic design     dynamic design     optimal design    

西北江交汇区航道整治试验研究

敖大光,曾志诚,李波,车进周

《中国工程科学》 2002年 第4卷 第5期   页码 67-70

摘要:

介绍了我国南方最大的河流珠江航道整治的成功经验。整治河段位于珠江西、北两江交汇区,不同类型浅滩多,水流条件复杂,而且是行洪干道之一,整治难度大。根据原型水文资料及河道地形资料,进行了水动力条件、来水来沙条件和河床演变的分析;结合模型试验,揭示了浅滩成因和形成机理;采取有针对性的整治工程布局,并应用在实际治理工程中。

关键词: 珠江航道     浅滩     整治工程    

标题 作者 时间 类型 操作

Exploring differentiated improvement strategies of cultivated land quality in China

期刊论文

Research progress on genetic improvement of

Chuanping YANG

期刊论文

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

Feng YANG, Manman WANG

期刊论文

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

Huali HAN

期刊论文

Embryo-mediated genome editing for accelerated genetic improvement of livestock

Zachariah MCLEAN, Björn OBACK, Götz LAIBLE

期刊论文

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

Jian-ya Jiang,Yang-wei Rao

期刊论文

Genetic improvement of wheat grain quality at CIMMYT

Carlos GUZMÁN, Karim AMMAR, Velu GOVINDAN, Ravi SINGH

期刊论文

Molecular regulation and genetic improvement of seed oil content in

Wei HUA,Jing LIU,Hanzhong WANG

期刊论文

Air quality improvement in Los Angeles—Perspectives for developing cities

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

期刊论文

FOR USE IN AGROECOSYSTEM IMPROVEMENT IN SEMI-ARID AREAS WITH A FOCUS ON CENTRAL ANATOLIA, TURKEY

期刊论文

Ductility improvement of GFRP-RC beams using precast confined concrete block in compression zone

期刊论文

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

Florian PAOLI, Tong WANG

期刊论文

Performance improvement of a pulse tube cryocooler with a single compressor through cascade utilization

Xuming LIU, Xiafan XU, Biao YANG, Xiaotong XI, Liubiao CHEN, Junjie WANG, Yuan ZHOU

期刊论文

On the improvement design of dynamic characteristics for the roller follower of a variable-speed plate

Hui Ching FAN, Hong Sen YAN

期刊论文

西北江交汇区航道整治试验研究

敖大光,曾志诚,李波,车进周

期刊论文