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HOW MULTISPECIES INTERCROP ADVANTAGE RESPONDS TO WATER STRESS: A YIELD-COMPONENT ECOLOGICAL FRAMEWORK

《农业科学与工程前沿（英文）》 2021年 第8卷 第3期   页码 416-431 doi: 10.15302/J-FASE-2021412

摘要：

Absolute yield and land use efficiency can be higher in multicrops. Though this phenomenon is common, it is not always the case. Also, these two benefits are frequently confused and do not necessarily occur together. Cropping choices become more complex when considering that multicrops are subject to strong spatial and temporal variation in average soil moisture, which will worsen with climate change. Intercropping in agroecosystems is expected to buffer this impact by favoring resistance to reduced humidity, but there are few empirical/experimental studies to validate this claim. It is not clear if relatively higher multicrop yield and land use efficiency will persist in the face of reduced soil moisture, and how the relation between these benefits might change. Here, we present a relatively simple framework for analyzing this situation. We propose a relative multicrop resistance (RMR) index that captures all possible scenarios of absolute and relative multicrop overyield under water stress. We dissect the ecological components of RMR to understand the relation between higher multicrop yield and land use efficiency and the ecological causes of different overyield scenarios. We demonstrate the use of this framework with data from a 128 microplot greenhouse experiment with small annual crops, arranged as seven-species multicrops and their corresponding monocrops, all under two contrasting watering regimes. We applied simple but robust statistical procedures to resulting data (based on bootstrap methods) to compare RMR, and its components, between different plants/plant parts. We also provide simple graphical tools to analyze the data.

 

关键词： agroecosystem sustainability     crop overyielding     intercrop drought resistance     overyield ecological components    

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Reliability-based robust design optimization of vehicle components, Part I: Theory

Yimin ZHANG

《机械工程前沿（英文）》 2015年 第10卷 第2期   页码 138-144 doi: 10.1007/s11465-015-0333-2

摘要：

The reliability-based design optimization, the reliability sensitivity analysis and robust design method are employed to present a practical and effective approach for reliability-based robust design optimization of vehicle components. A procedure for reliability-based robust design optimization of vehicle components is proposed. Application of the method is illustrated by reliability-based robust design optimization of axle and spring. Numerical results have shown that the proposed method can be trusted to perform reliability-based robust design optimization of vehicle components.

关键词： vehicle components     reliability-based design optimization     reliability-based sensitivity analysis     multi-objective optimization     robust design    

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Experimental study on influence of operating parameters on tar components from corn straw gasification

Shuai GUO, Xiao WEI, Deyong CHE, Hongpeng LIU, Baizhong SUN

《能源前沿（英文）》 2021年 第15卷 第2期   页码 374-383 doi: 10.1007/s11708-020-0710-3

摘要： Gasification is a promising approach for converting solid fuel sources, including renewable ones like biomass, for use. The main problem in biomass gasification is the formation of condensable tars, including polycyclic aromatic hydrocarbons (PAHs). This paper investigated the conversion of tar components during corn straw gasification. It analyzed collected tar components using a gas chromatograph-mass spectrograph (GC-MS). Experimental results indicate that, with increasing temperature from 700°C to 900°C, the concentrations of benzene, indene, phenanthrene, naphthalene, acenaphthylene, fluorene, and pyrene increased whereas those of toluene, phenol, 1-methylnaphthalene, and 2-methylnaphthalene decreased. As the equivalence ratio (ER) increased from 0.21 to 0.34, the concentrations of indene and phenanthrene increased from 0.148% and 0.087% to 0.232% and 0.223%, respectively. Further, the phenol content increased as ER increased from 0.21 to 0.26 and then decreased as the ER increased further to 0.34. Other parameters like the steam/biomass (S/B) ratio and catalyst also played a critical role in tar reduction. This paper demonstrates the conversion of some tar components and elucidates their chemical properties during gasification.

关键词： gasification     tar components     operating parameters    

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Topological reorganization and functional alteration of distinct genomic components in gallbladder cancer

《医学前沿（英文）》 doi: 10.1007/s11684-023-1008-8

摘要： Altered three-dimensional architecture of chromatin influences various genomic regulators and subsequent gene expression in human cancer. However, knowledge of the topological rearrangement of genomic hierarchical layers in cancer is largely limited. Here, by taking advantage of in situ Hi-C, RNA-sequencing, and chromatin immunoprecipitation sequencing (ChIP-seq), we investigated structural reorganization and functional changes in chromosomal compartments, topologically associated domains (TADs), and CCCTC binding factor (CTCF)-mediated loops in gallbladder cancer (GBC) tissues and cell lines. We observed that the chromosomal compartment A/B switch was correlated with CTCF binding levels and gene expression changes. Increased inter-TAD interactions with weaker TAD boundaries were identified in cancer cell lines relative to normal controls. Furthermore, the chromatin short loops and cancer unique loops associated with chromatin remodeling and epithelial–mesenchymal transition activation were enriched in cancer compared with their control counterparts. Cancer-specific enhancer–promoter loops, which contain multiple transcription factor binding motifs, acted as a central element to regulate aberrant gene expression. Depletion of individual enhancers in each loop anchor that connects with promoters led to the inhibition of their corresponding gene expressions. Collectively, our data offer the landscape of hierarchical layers of cancer genome and functional alterations that contribute to the development of GBC.

关键词： 3D genome     cancer     TADs     loop     gene regulation    

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CONCENTRATIONS AND FLUXES OF DISSOLVED NUTRIENTS IN THE YANGTZE RIVER: LONG-TERM TRENDS AND ECOLOGICAL

《农业科学与工程前沿（英文）》 2021年 第8卷 第4期   页码 559-567 doi: 10.15302/J-FASE -2020344

摘要：

Intensifying human activity in the Yangtze River basin has substantially increased nutrient concentrations in the Yangtze River Estuary, leading to degradation of the coastal environment. Analysis of nutrient determinations published over the past 50 years reveals a gradual decreasing trend in the concentrations and fluxes of dissolved silicate (DSi). However, both dissolved inorganic nitrogen (DIN) and dissolved inorganic phosphate (DIP) concentrations have increased significantly since the 1970s. The frequency of and area covered by red tide outbreaks have increased greatly during this period, mainly due to changes in nutrient supply ratios [i.e., N/P (DIN/DIP), N/Si (DIN/DSi), P/Si (DIP/DSi)]. A strong correlation was found between the riverine DIN fluxes and the estimated DIN inputs from the major N sources, particularly fertilizers and atmospheric deposition. The data provide a comprehensive assessment of nutrients in the Yangtze River basin and their ecological impacts and indicate a potentially significant influence of atmospheric deposition on DIN loadings and fluxes.

 

关键词： atmospheric deposition / ecological impacts / nitrogen sources / nutrients / Yangtze delta    

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Characteristics of chemical components in PM

Jianwu SHI,Xiang DING,Yue ZHOU,Ran YOU,Lu HUANG,Jiming HAO,Feng XIANG,Jian YANG,Ze SHI,Xinyu HAN,Ping NING

《环境科学与工程前沿（英文）》 2016年 第10卷 第5期 doi: 10.1007/s11783-016-0841-2

摘要： The mass concentrations of PM were studied at a plateau city. Seasonal and spatial variation of chemical components in PM were analyzed. Primary emissions were the main contributors of PM . A sampling campaign including summer, autumn and winter of 2014 and spring of 2015 was accomplished to obtain the characteristic of chemical components in PM at three sites of Kunming, a plateau city in South-west China. Nine kinds of water-soluble inorganic ions (WSI), organic and element carbon (OC and EC) in PM were analyzed by ion chromatography and thermal optical reflectance method, respectively. Results showed that the average concentrations of total WSI, OC and EC were 22.85±10.95 μg·m , 17.83±9.57 μg·m and 5.11±4.29 μg·m , respectively. They totally accounted for 53.0% of PM . Secondary organic and inorganic aerosols (SOA and SIA) were also assessed by the minimum ratio of OC/EC, nitrogen and sulfur oxidation ratios. The annual average concentrations of SOA and SIA totally accounted for 28.3% of the PM concentration. The low proportion suggested the primary emission was the main source of PM in Kunming. However, secondary pollution in the plateau city should also not be ignorable, due to the appropriate temperature and strong solar radiation, which can promote the atmospheric photochemical reactions.

关键词： PM2.5     Plateau city     Organic carbon     Element carbon     Inorganic ions     Secondary components    

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Ecological conservation, remediation and construction for building an ecological civilization in China: concepts for ecological activity

Guofang SHEN

《农业科学与工程前沿（英文）》 2017年 第4卷 第4期   页码 376-379 doi: 10.15302/J-FASE-2017186

摘要： This paper explains and discusses the concepts of ecological conservation and construction in China in three parts. The first part provides a brief description of the historical background of ecological activities in China and their major achievements in the past. The second part is a comprehensive review of various types of ecological control activity aimed at the improvement of natural and artificially established ecosystems at the landscape, regional (watershed) and higher levels. The scope of and differences between some ecological terms used in China such as ecological protection, conservation, remediation (rehabilitation), restoration as well as the reestablishment of new ecosystems are elaborated. The review suggests that the term “ecological conservation and construction” should be used to embrace all types of ecological control activity in China. Finally, five guidelines are proposed for promoting the implementation of ecological conservation and construction in China based on the two important governmental documents related to the development of ecological civilization in China.

关键词： ecological conservation     development     construction ”     description     important governmental    

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陶瓷喷墨打印增材制造技术 Review

Brian Derby

《工程（英文）》 2015年 第1卷 第1期   页码 113-123 doi: 10.15302/J-ENG-2015014

摘要：

陶瓷喷墨打印是一种基于微滴累加的成形技术，典型的微滴体积为10~100 pL。实现微滴累加成形的关键是开发稳定的陶瓷墨水，合适的墨水需要满足由雷诺数和韦伯数定义的流变特性参数空间。在微滴累加成形过程中，微滴首先与成形面碰撞变形并消耗动能，然后在毛细管力作用下铺展并达到平衡状态。已经可以确定的是打印过程中微滴相互作用并形成一维线性特征的机理，但是对二维和三维结构成形机理的认识还处于较低水平，成形二维面的稳定性低于成形一维线性结构。多数情况下，墨水通过蒸发固化，微滴碰撞基体所产生的“咖啡环”缺陷需要通过固化工艺加以控制。已经有大量文献报道了使用喷墨打印技术成形各种类型小型陶瓷零件的成功案例。作为一种未来的制造技术，陶瓷喷墨打印技术有广阔的应用前景。本综述的目的是探索陶瓷喷墨打印技术未来潜在的研究领域，加强对这种制造方法的理解。

关键词： 增材制造     3D打印     喷墨打印     陶瓷零件    

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Reliability-based robust design optimization of vehicle components, Part II: Case studies

Yimin ZHANG

《机械工程前沿（英文）》 2015年 第10卷 第2期   页码 145-153 doi: 10.1007/s11465-015-0334-1

摘要：

The reliability-based optimization, the reliability-based sensitivity analysis and robust design method are employed to propose an effective approach for reliability-based robust design optimization of vehicle components in Part I. Applications of the method are further discussed for reliability-based robust optimization of vehicle components in this paper. Examples of axles,torsion bar, coil and composite springs are illustrated for numerical investigations. Results have shown the proposed method is an efficient method for reliability-based robust design optimization of vehicle components.

关键词： vehicle axles and springs     reliability-based design optimization     reliability-based sensitivity analysis     multi-objective optimization     robust design    

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Connected morphable components-based multiscale topology optimization

Jiadong DENG, Claus B. W. PEDERSEN, Wei CHEN

《机械工程前沿（英文）》 2019年 第14卷 第2期   页码 129-140 doi: 10.1007/s11465-019-0532-3

摘要： The advances of manufacturing techniques, such as additive manufacturing, have provided unprecedented opportunities for producing multiscale structures with intricate latticed/cellular material microstructures to meet the increasing demands for parts with customized functionalities. However, there are still difficulties for the state-of-the-art multiscale topology optimization (TO) methods to achieve manufacturable multiscale designs with cellular materials, partially due to the disconnectivity issue when tiling material microstructures. This paper attempts to address the disconnectivity issue by extending component-based TO methodology to multiscale structural design. An effective linkage scheme to guarantee smooth transitions between neighboring material microstructures (unit cells) is devised and investigated. Associated with the advantages of components-based TO, the number of design variables is greatly reduced in multiscale TO design. Homogenization is employed to calculate the effective material properties of the porous materials and to correlate the macro/structural scale with the micro/material scale. Sensitivities of the objective function with respect to the geometrical parameters of each component in each material microstructure have been derived using the adjoint method. Numerical examples demonstrate that multiscale structures with well-connected material microstructures or graded/layered material microstructures are realized.

关键词： multiscale topology optimization     morphable component     material microstructure     homogenization    

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Research on port ecological suitability evaluation index system and evaluation model

Yaofeng XIE,Xia LV,Ru LIU,Liuyan MAO,Xiaoxi LIU

《结构与土木工程前沿（英文）》 2015年 第9卷 第1期   页码 65-70 doi: 10.1007/s11709-014-0258-6

摘要： Along with the rapid development of port building, the negative impacts of port’s construction and operation on the coastline ecosystem are also increasingly strong. Therefore, it’s urgent to establish a scientific and complete system of port ecological suitability evaluation. This paper pointed out the characteristics of port ecological effects and the principles of selecting evaluation index, and used the “pressure-state-response (PSR)” model to analysis the various pressures on the environment caused by port construction and operation, and the system’s response. On this basis, we constructed the port ecological suitability evaluation index. This model used the combination of qualitative and quantitative analytic hierarchy process, to meet the multi-level, multi-objective characteristics of evaluation index system. The evaluation index system and evaluation model can be used to analysis the ecological suitability of port projects comprehensively and have some guiding significance to the port ecological suitability evaluation.

关键词： port     ecological suitability     press-state-response (PSR) model     evaluation index system    

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Forecast method for used number of parts and components based on complex network

LIU Fu-yun, QI Guo-ning, YANG Qing-hai

《机械工程前沿（英文）》 2006年 第1卷 第4期   页码 479-484 doi: 10.1007/s11465-006-0064-5

摘要： Applying directed complex network to model the main structure of a product family, according to in-degree bi-logarithmic coordinate distribution curve and distribution rule of nodes of the network, in-degree evolving rule of nodes of the network is presented and analytic expression of in-degree probability density of nodes is derived. Through the analysis of the relation between existing kinds of components and existing product numbers, an expression of the relation between kinds of components and product numbers is derived. A forecast method for the increment of component numbers and parts based on the increment of products is presented. As an example, the component numbers of an industrial steam turbine product family is forecasted, forecast result verified and forecast error analyzed.

关键词： complex network     industrial     component     analytic expression     forecast    

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HIGH QUALITY DEVELOPMENTAL APPROACH FOR SOIL AND WATER CONSERVATION AND ECOLOGICAL PROTECTION ON THE

《农业科学与工程前沿（英文）》 2021年 第8卷 第4期   页码 501-511 doi: 10.15302/J-FASE-2021425

摘要：

The Loess Plateau is the core area in the Yellow River basin for implementing environmental protection and high-quality development strategies. A series of ecological projects has implemented aimed at soil and water conservation and ecological management on the Loess Plateau over the past 70 years. The effects of the ecological projects are apparent mainly through a marked increase in vegetation cover, controlled soil erosion and reduced flow of sediment into the Yellow River, continual optimization of the industrial structure and increased production from arable land, poverty alleviation and greater prosperity, and optimal allocation of space for biological organisms. Major problems have also been analyzed in ecological management including the fragile ecosystem of the region, maintaining the stability of vegetation, lower agricultural productivity and continued risk from natural disasters. Some suitable schemes and models have been developed for the coordinated development of the region through research and demonstration, striking the optimum balance between rural industry and ecology, and increased regional capacity to supply high-quality ecological products. Countermeasures to address the problems are suggested to guide ecological management and high-quality development in the future.

 

关键词： ecological management     high quality development     industrial structure     soil erosion     soil and water conservation     Loess Plateau    

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CNC programming system for complex components based on KBE within integrated environment of CAD/CAPP/

Shengwen ZHANG, Guicheng WANG, Liang ZHANG, Xifeng FANG

《机械工程前沿（英文）》 2009年 第4卷 第1期   页码 97-102 doi: 10.1007/s11465-009-0007-z

摘要： To promote the research and development of modern digital and intelligent manufacturing technology and overcome shortcomings of computerized numerical control(CNC) programming for complex components, an innovative idea has been proposed to introduce knowledge based engineering (KBE) into the field of CNC programming within the integrated environment of CAD/CAPP/CAM. This paper constructs the architecture of CNC programming based on KBE within CAD/CAPP/CAM and explores the key technology of applying KBE to CNC programming — knowledge representation, knowledge acquisition, knowledge reasoning, and generalized knowledge base system of CNC programming. The integration of the CAD/CAM system and the CAPP system of enterprises has been achieved by taking the powerful CAD/CAM system of UG NX as a platform. The prototype system of CNC programming for complex components based on KBE within CAD/CAPP/CAM has been developed by means of UG/Open,VC++6.0, and SQL Sever 2000. Finally, a frame example, one of the complex components of a marine diesel, is presented, and the academic production and the intelligence of the system are verified.

关键词： NC programming     CAD/CAPP/CAM     KBE    

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CONCENTRATIONS AND FLUXES OF DISSOLVED NUTRIENTS IN THE YANGTZE RIVER: LONG-TERM TRENDS AND ECOLOGICAL

Yandan FU, Jiahui KANG, Ziyue LI, Xuejun LIU, Wen XU

《农业科学与工程前沿（英文）》 2021年 第8卷 第4期   页码 559-567 doi: 10.15302/J-FASE-2020344

摘要： Intensifying human activity in the Yangtze River Basin (YRB) has substantially increased nutrient concentrations in the Yangtze River Estuary, leading to degradation of the coastal environment. Analysis of nutrient determinations published over the past 50 years reveals a gradual decreasing trend in the concentrations and fluxes of dissolved silicate (DSi). However, both dissolved inorganic nitrogen (DIN) and dissolved inorganic phosphate (DIP) concentrations have increased significantly since the 1970s. The frequency and area covered by red tide outbreaks have increased greatly during this period, mainly due to changes in nutrient supply ratios [i.e., N/P (DIN/DIP), N/Si (DIN/DSi), P/Si (DIP/DSi)]. A strong correlation was found between the riverine DIN fluxes and the estimated DIN inputs from the major N sources, particularly fertilizers and atmospheric deposition. The data provide a comprehensive assessment of nutrients in the YRB and their ecological impacts and indicate a potentially significant influence of atmospheric deposition on DIN loadings and fluxes.

关键词： atmospheric deposition     ecological impacts     nitrogen sources     nutrients     Yangtze River Delta    

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标题 作者 时间 类型 操作

HOW MULTISPECIES INTERCROP ADVANTAGE RESPONDS TO WATER STRESS: A YIELD-COMPONENT ECOLOGICAL FRAMEWORK

期刊论文

Reliability-based robust design optimization of vehicle components, Part I: Theory

Yimin ZHANG

期刊论文

Experimental study on influence of operating parameters on tar components from corn straw gasification

Shuai GUO, Xiao WEI, Deyong CHE, Hongpeng LIU, Baizhong SUN

期刊论文

Topological reorganization and functional alteration of distinct genomic components in gallbladder cancer

期刊论文

CONCENTRATIONS AND FLUXES OF DISSOLVED NUTRIENTS IN THE YANGTZE RIVER: LONG-TERM TRENDS AND ECOLOGICAL

期刊论文

Characteristics of chemical components in PM

Jianwu SHI,Xiang DING,Yue ZHOU,Ran YOU,Lu HUANG,Jiming HAO,Feng XIANG,Jian YANG,Ze SHI,Xinyu HAN,Ping NING

期刊论文

Ecological conservation, remediation and construction for building an ecological civilization in China: concepts for ecological activity

Guofang SHEN

期刊论文

陶瓷喷墨打印增材制造技术

Brian Derby

期刊论文

Reliability-based robust design optimization of vehicle components, Part II: Case studies

Yimin ZHANG

期刊论文

Connected morphable components-based multiscale topology optimization

Jiadong DENG, Claus B. W. PEDERSEN, Wei CHEN

期刊论文

Research on port ecological suitability evaluation index system and evaluation model

Yaofeng XIE,Xia LV,Ru LIU,Liuyan MAO,Xiaoxi LIU

期刊论文

Forecast method for used number of parts and components based on complex network

LIU Fu-yun, QI Guo-ning, YANG Qing-hai

期刊论文

HIGH QUALITY DEVELOPMENTAL APPROACH FOR SOIL AND WATER CONSERVATION AND ECOLOGICAL PROTECTION ON THE

期刊论文

CNC programming system for complex components based on KBE within integrated environment of CAD/CAPP/

Shengwen ZHANG, Guicheng WANG, Liang ZHANG, Xifeng FANG

期刊论文

CONCENTRATIONS AND FLUXES OF DISSOLVED NUTRIENTS IN THE YANGTZE RIVER: LONG-TERM TRENDS AND ECOLOGICAL

Yandan FU, Jiahui KANG, Ziyue LI, Xuejun LIU, Wen XU

期刊论文