资源类型

期刊论文 355

年份

2023 18

2022 30

2021 17

2020 28

2019 23

2018 14

2017 23

2016 14

2015 30

2014 12

2013 14

2012 4

2011 9

2010 15

2009 5

2008 17

2007 23

2006 8

2005 8

2004 13

展开 ︾

关键词

生态文明 14

可持续发展 7

生态环境 7

秦巴山脉区域 5

农业生态工程 4

生态保护 4

生态文明建设 4

严格雪崩准则 3

区域协同 3

Bent函数 2

Walsh循环谱 2

功能 2

双目标渐进法 2

战略 2

生态工程 2

生态恢复 2

绿色发展 2

自相关函数 2

高质量发展 2

展开 ︾

检索范围:

排序: 展示方式:

Optimization of the power, efficiency and ecological function for an air-standard irreversible Dual-Miller

Zhixiang WU, Lingen CHEN, Yanlin GE, Fengrui SUN

《能源前沿(英文)》 2019年 第13卷 第3期   页码 579-589 doi: 10.1007/s11708-018-0557-z

摘要: This paper establishes an irreversible Dual-Miller cycle (DMC) model with the heat transfer (HT) loss, friction loss (FL) and other internal irreversible losses. To analyze the effects of the cut-off ratio ( ) and Miller cycle ratio ( ) on the power output ( ), thermal efficiency ( ) and ecological function ( ), obtain the optimal and optimal , and compare the performance characteristics of DMC with its simplified cycles and with different optimization objective functions, the , and of irreversible DMC are analyzed and optimized by applying the finite time thermodynamic (FTT) theory. Expressions of , and are derived. The relationships among , , and compression ratio ( ) are obtained by numerical examples. The effects of and on , , , maximum power output ( ), maximum efficiency ( ) and maximum ecological function ( ) are analyzed. Performance differences among the DMC, the Otto cycle (OC), the Dual cycle (DDC), and the Otto-Miller cycle (OMC) are compared for fixed design parameters. Performance characteristics of irreversible DMC with the choice of , and as optimization objective functions are analyzed and compared. The results show that the irreversible DMC engine can reach a twice-maximum power, a twice-maximum efficiency, and a twice-maximum ecological function, respectively. Moreover, when choosing as the optimization objective, there is a 5.2% of improvement in while there is a drop of only 2.7% in compared to choosing as the optimization objective. However, there is a 5.6% of improvement in while there is a drop of only 1.3% in compared to choosing as the optimization objective.

关键词: finite-time thermodynamics     Dual-Miller cycle     power output     thermal efficiency     ecological function    

3S技术在区域生态功能区划中的应用——以河南省濮阳市为案例

卞有生,蔡博峰,赵楠

《中国工程科学》 2005年 第7卷 第12期   页码 54-60

摘要:

生态功能区划是区域社会经济协调发展的基础性工作,3S技术则是保证区划科学与准确的重要技术手段。以河南省濮阳市为例,介绍了3S技术在区域生态功能区划中的应用及其优势与特点,即数据的准确性、现势性和科学性得到进一步提高,而且空间分析功能充分实现了不同权重生态因子的叠加,同时在区划过程中充分考虑生态格局对生态功能的影响,因而区划结果更具科学性和现实意义。

关键词: 生态功能区划     3S     空间分析     生态格局    

保障我国草地生态与食物安全的战略和政策

“中国草地生态保障与食物安全战略研究”项目组

《中国工程科学》 2016年 第18卷 第1期   页码 8-16 doi: 10.15302/J-SSCAE-2016.01.002

摘要:

草地是我国面积最大的陆地生态系统,在保障国家生态安全、食物安全和弘扬中华草原文明中具有突出的战略地位。本文分析了我国草地资源、草地生态功能、生产力的现状和变动趋势及其主要的影响因素,阐述了目前和未来我国草地生态保障、草地生产力和草牧业发展面临的机遇、挑战和潜力。在以上内容分析的基础上,提出了我国保障草地生态安全和发展草牧业的战略目标、战略重点、关键措施和主要政策建议。

关键词: 草地     生态保障     食物安全     发展战略     政策建议    

Exergetic sustainability evaluation and optimization of an irreversible Brayton cycle performance

Mohammad H. AHMADI,Mohammad-Ali AHMADI,Esmaeil ABOUKAZEMPOUR,Lavinia GROSU,Fathollah POURFAYAZ,Mokhtar BIDI

《能源前沿(英文)》 2019年 第13卷 第2期   页码 399-410 doi: 10.1007/s11708-017-0445-y

摘要: Owing to the energy demands and global warming issue, employing more effective power cycles has become a responsibility. This paper presents a thermodynamical study of an irreversible Brayton cycle with the aim of optimizing the performance of the Brayton cycle. Moreover, four different schemes in the process of multi-objective optimization were suggested, and the outcomes of each scheme are assessed separately. The power output, the concepts of entropy generation, the energy, the exergy output, and the exergy efficiencies for the irreversible Brayton cycle are considered in the analysis. In the first scheme, in order to maximize the exergy output, the ecological function and the ecological coefficient of performance, a multi-objective optimization algorithm (MOEA) is used. In the second scheme, three objective functions including the exergetic performance criteria, the ecological coefficient of performance, and the ecological function are maximized at the same time by employing MOEA. In the third scenario, in order to maximize the exergy output, the exergetic performance criteria and the ecological coefficient of performance, a MOEA is performed. In the last scheme, three objective functions containing the exergetic performance criteria, the ecological coefficient of performance, and the exergy-based ecological function are maximized at the same time by employing multi-objective optimization algorithms. All the strategies are implemented via multi-objective evolutionary algorithms based on the NSGAII method. Finally, to govern the final outcome in each scheme, three well-known decision makers were employed.

关键词: entropy generation     exergy     Brayton cycle     ecological function     irreversibility    

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    

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    

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    

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    

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    

Lung function and air pollution exposure in adults with asthma in Beijing: a 2-year longitudinal panel

《医学前沿(英文)》 2022年 第16卷 第4期   页码 574-583 doi: 10.1007/s11684-021-0882-1

摘要: The effect of air pollution on the lung function of adults with asthma remains unclear to date. This study followed 112 patients with asthma at 3-month intervals for 2 years. The pollutant exposure of the participants was estimated using the inverse distance weight method. The participants were divided into three groups according to their lung function level at every visit. A linear mixed-effect model was applied to predict the change in lung function with each unit change in pollution concentration. Exposure to carbon monoxide (CO) and particles less than 2.5 micrometers in diameter (PM2.5) was negatively associated with large airway function in participants. In the severe group, exposure to chronic sulfur dioxide (SO2) was negatively associated with post-bronchodilator forced expiratory flow at 50%, between 25% and 75% of vital capacity % predicted (change of 95% CI per unit: −0.34 (−0.55, −0.12), −0.24 (−0.44, −0.03), respectively). In the mild group, the effect of SO2 on the small airways was similar to that in the severe group, and it was negatively associated with large airway function. Exposure to CO and PM2.5 was negatively associated with the large airway function of adults with asthma. The negative effects of SO2 were more evident and widely observed in adults with severe and mild asthma than in adults with moderate asthma. Patients with asthma react differently to air pollutants as evidenced by their lung function levels.

关键词: lung function     asthma     air pollution     adult    

Relationship between the development of energy and mineral resources and ecological conservation redline

Dawei ZHANG

《工程管理前沿(英文)》 2019年 第6卷 第4期   页码 557-563 doi: 10.1007/s42524-019-0077-5

摘要: From a philosophical point of view, this study discusses the dialectical relationship between the development of energy and mineral resources and the ecological conservation redline. We propose that the ecological conservation redline and the development of energy and mineral resources should be guided by ecological civilization construction, that is, the energy and mineral resources should be rationally developed under the condition that the ecological environment is protected. This study analyzes the influence of the development of energy and mineral resources on the ecological environment. The handling of mining rights within the ecological conservation redline based on the law and the reduction of the influence of the development of energy mineral resources on the ecological environment by science and technology are presented. The environmental assessment system and technical standards for energy and mineral development are suggested to implement policies and measures for the disposal of mining rights within the redline and facilitate technological innovations of ecological conservation for energy and mineral development. Hence, a coordinated development between the ecological conservation redline and the development of energy and mineral resources can be promoted.

关键词: ecological conservation redline     development of energy and mineral resources     coordinated development    

The function and regulation of OTU deubiquitinases

Jiansen Du, Lin Fu, Yingli Sui, Lingqiang Zhang

《医学前沿(英文)》 2020年 第14卷 第5期   页码 542-563 doi: 10.1007/s11684-019-0734-4

摘要: Post-translational modification of cellular proteins by ubiquitin regulates numerous cellular processes, including cell division, immune responses, and apoptosis. Ubiquitin-mediated control over these processes can be reversed by deubiquitinases (DUBs), which remove ubiquitin from target proteins and depolymerize polyubiquitin chains. Recently, much progress has been made in the DUBs. In humans, the ovarian tumor protease (OTU) subfamily of DUBs includes 16 members, most of which mediate cell signaling cascades. These OTUs show great variation in structure and function, which display a series of mechanistic features. In this review, we provide a comprehensive analysis of current progress in character, structure and function of OTUs, such as the substrate specificity and catalytic activity regulation. Then we discuss the relationship between some diseases and OTUs. Finally, we summarize the structure of viral OTUs and their function in immune escape and viral survival. Despite the challenges, OTUs might provide new therapeutic targets, due to their involvement in key regulatory processes.

关键词: ubiquitin     OTU deubiquitinases     structure     function     regulation    

类差分平衡函数的性质及其应用

张文英,李世取

《中国工程科学》 2004年 第6卷 第3期   页码 45-52

摘要:

定义了布尔函数的类差分和类差分平衡函数,研究了类差分平衡函数的密码学性质以及构造方法。作为类差分平衡函数的应用,给出了〓上逻辑函数是完全非线性函数的充要条件,并在首先分析得到所有四元类差分平衡函数的基础上,编程搜索出〓上所有的完全非线性函数。

关键词: Bent函数     完全非线性函数     2-基展开     类差分     类自相关函数     类差分平衡函数    

中国红树林湿地与生态工程的几个问题

林鹏

《中国工程科学》 2003年 第5卷 第6期   页码 33-38

摘要:

简述红树林湿地在滨海湿地中的地位,红树林的种类和分布,红树林类群的界定,湿地保护中的重要性,红树林的生态、社会和经济价值。着重讨论中国红树林生态工程中面临的四个问题:1.红树林生态恢复的关键是宜林地的选择标准;2.红树林区海堤修复工程的生态模式;3.防止引种时带进外来有害物种的生态入侵;4.要以最小的资源环境代价,谋求经济社会最大限度的发展,从而促进红树林湿地的保护与发展。

关键词: 红树林     湿地     生态恢复     生态入侵    

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    

标题 作者 时间 类型 操作

Optimization of the power, efficiency and ecological function for an air-standard irreversible Dual-Miller

Zhixiang WU, Lingen CHEN, Yanlin GE, Fengrui SUN

期刊论文

3S技术在区域生态功能区划中的应用——以河南省濮阳市为案例

卞有生,蔡博峰,赵楠

期刊论文

保障我国草地生态与食物安全的战略和政策

“中国草地生态保障与食物安全战略研究”项目组

期刊论文

Exergetic sustainability evaluation and optimization of an irreversible Brayton cycle performance

Mohammad H. AHMADI,Mohammad-Ali AHMADI,Esmaeil ABOUKAZEMPOUR,Lavinia GROSU,Fathollah POURFAYAZ,Mokhtar BIDI

期刊论文

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

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

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

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

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

Lung function and air pollution exposure in adults with asthma in Beijing: a 2-year longitudinal panel

期刊论文

Relationship between the development of energy and mineral resources and ecological conservation redline

Dawei ZHANG

期刊论文

The function and regulation of OTU deubiquitinases

Jiansen Du, Lin Fu, Yingli Sui, Lingqiang Zhang

期刊论文

类差分平衡函数的性质及其应用

张文英,李世取

期刊论文

中国红树林湿地与生态工程的几个问题

林鹏

期刊论文

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

期刊论文