期刊文献+
共找到15篇文章
< 1 >
每页显示 20 50 100
DNV安全评价软件进行定量风险评估的运用 被引量:2
1
作者 瞿文华 《石油化工安全技术》 2002年第3期6-7,11,共3页
详细介绍了DNV安全评价软件对400kt/a乙烯装置热区系统进行定量风险评估的运用。阐述了此软件对保证生产装置安全生产的重要性。
关键词 DNV安全评价软件 定量风险评估 运用 乙烯装置 热区系统
下载PDF
Monitoring Land Use Dynamics in Chanthaburi Province of Thailand Using Digital Remotely Sensed Images 被引量:12
2
作者 SHENRUNPING I.KHEORUENROMNE 《Pedosphere》 SCIE CAS CSCD 2003年第2期157-164,共8页
A comprehensive method of image classification was developed for monitoring land use dynamics in Chanthaburi Province of Tailand. RS (Remote Sensing), GIS (Geographical Information System), GPS (Global Positioning Sys... A comprehensive method of image classification was developed for monitoring land use dynamics in Chanthaburi Province of Tailand. RS (Remote Sensing), GIS (Geographical Information System), GPS (Global Positioning System) and ancillary data were combined by the method which adopts the main idea of classifying images by steps from decision tree method and the hybridized supervised and unsupervised classification. An integration of automatic image interpretation, ancillary materials and expert knowledge was realized. Two subscenes of Landsat 5 Thematic Mapper (TM) images of bands 3, 4 and 5 obtained on December 15, 1992, and January 17, 1999, were used for image processing and spatial data analysis in the study. The overall accuracy of the results of classification reached 90%, which was verified by field check.Results showed that shrimp farm land, urban and traffic land, barren land, bush and agricultural developing area increased in area, mangrove, paddy field, swamp and marsh land, orchard and plantation, and tropical grass land decreased, and the forest land kept almost stable. Ecological analysis on the land use changes showed that more attentions should be paid on the effect of land development on ecological environment in the future land planning and management. 展开更多
关键词 image classification land use dynamics remote sensing tropical area
下载PDF
Optimizing Hotspot Areas for Ecological Planning and Management Based on Biodiversity and Ecosystem Services 被引量:12
3
作者 XIAO Yang OUYANG Zhiyun +3 位作者 XU Weihua XIAO Yi ZHENG Hua XIAN Chaofan 《Chinese Geographical Science》 SCIE CSCD 2016年第2期256-269,共14页
The significance of biodiversity and ecosystem services are gradually recognized by human as an approach towards sustainability, so it is important to understand relationships and congruence between them to support co... The significance of biodiversity and ecosystem services are gradually recognized by human as an approach towards sustainability, so it is important to understand relationships and congruence between them to support conservation planning, especially in the hotspot areas with a prominent role in conservation. However, the management of most conservation hotspots mainly focused on biodiversity, and rarely concerned with ecosystem services. With the aim of proposing criteria for conservation strategies that contribute to the optimization of biodiversity and ecosystem services, in this study, a Geographic Information System(GIS)-based approach was designed to estimate and map the biodiversity and ecosystem services in Chongqing Municipality of China. Furthermore, the distributions of hotspot areas for biodiversity and ecosystem services were mapped based on the relationship between cumulative ecosystem services and areas. Finally the statistical analysis was processed focused on specific conservation objectives. The results showed that hotspot areas can conserve the most biodiversity but with the least ecosystem services under the conservation plans target to biodiversity conservation. In contrast, depending on the ecosystem services of interest, hotspot areas can conserve the largest ecosystem services but with the least biodiversity. By integrating biodiversity and ecosystem services into conservation plan, we found that the conservation and regeneration of these small areas, would contribute to a conservation of 44% of the biodiversity hotspot and 14%–42% of the ecosystem services hotspot. Moreover, the current nature reserve selection was not maximize the biodiversity and ecosystem services compared to integration strategy, indicating that hotspot areas conservation and selection is vital for optimization protection of biodiversity and ecosystem services, and has practical significance for natural resources and ecosystem management. 展开更多
关键词 biodiversity ecosystem services hotspot nature reserve Chongqing Municipality China
下载PDF
Data Center as a Key Player of a District Electric Power and Heat Network System: A Comparison in Urban and Suburb Regions
4
作者 Shunsuke Mori Yuuki Hori +1 位作者 Masashi Ohkura Kazuhisa Kamegai 《Computer Technology and Application》 2013年第10期548-555,共8页
A DC (data center) demands air-conditioning power as large as the 1/3-1/2 of total electricity consumption. Thus, energy saving of cooling power of DC yields considerable effect on both economic and environmental vi... A DC (data center) demands air-conditioning power as large as the 1/3-1/2 of total electricity consumption. Thus, energy saving of cooling power of DC yields considerable effect on both economic and environmental views. PV (Photovoltaic) and absorption refrigerator with CGS (cogeneration systems) or gas boiler are possible power saving options. The waste warm air from DC would be utilized for greenhouse heating when DC and greenhouse locate near in the suburbs. In this study, the authors develop an energy network model to assess the potential contribution of DC as a major electric power and chilled air consumer as well as the warm air supplier in a district to the energy efficiency improvement. The evaporation heat of LNG (liquefied natural gas) utilization is also considered as well as PV, CGS. This model is applied to the cases of the urban area in Tokyo which involves athletic center, shops and hospital and the suburbs including greenhouse and then compared. 展开更多
关键词 Data center distributed energy systems urban and suburbs.
下载PDF
A Neuro-Fuzzy Based Adaptive Set-Point Heat Exchanger Control Scheme in District Heating System
5
作者 Liang Huang Zaiyi Liao Zhao Lian 《Journal of Civil Engineering and Architecture》 2012年第11期1584-1588,共5页
The control of heat exchange stations in district heating system is critical for the overall energy efficiency and can be very difficult due to high level of complexity. A conventional method is to control the equipme... The control of heat exchange stations in district heating system is critical for the overall energy efficiency and can be very difficult due to high level of complexity. A conventional method is to control the equipment such that the temperature of hot water supply is maintained at a set-point that may be a fixed value or be compensated against the external temperature. This paper presents a novel scheme that can determine the optimal set-point of hot water supply that maximizes the energy efficiency whilst providing sufficient heating capacity to the load. This scheme is based on Adaptive Neuro-Fuzzy Inferential System. The aim of this study is to improve the overall performance of district heating systems. 展开更多
关键词 District heating system NEURO-FUZZY inferential sensor energy efficiency CONTROL
下载PDF
Heat transfer analysis and experimental verification of cast heat exchanger 被引量:1
6
作者 俞洁 董蕾 +1 位作者 张欢 由世俊 《Journal of Central South University》 SCIE EI CAS 2012年第6期1610-1614,共5页
From the viewpoints of environmental conservation and energy efficiency,seawater-source heat pump system(SWHP) to provide district cooling and heating is applied in coastal areas.Based on the system,a heat transfer mo... From the viewpoints of environmental conservation and energy efficiency,seawater-source heat pump system(SWHP) to provide district cooling and heating is applied in coastal areas.Based on the system,a heat transfer model was established for cast heat exchanger(CHE) adopted by SWHP systems.The CHE consists of pipes immersed in the seawater and used for transferring heat between the seawater and the heat exchanger pipes of SWHP system.An experimental study was carried out to test the validity of the model.A program was developed in VB language and the effects of inlet temperature,flow rate of the secondary refrigerant and length of CHE on the results were investigated.The results of the numerical simulation are in consistence with the experiments in both winter and summer conditions.As a result,application of SWHP systems with CHE in coastal areas in China is feasible due to the favorable geographical conditions and environment. 展开更多
关键词 seawater-source heat pump cast heat exchanger mathematical model experimental verification numerical simulation
下载PDF
Developing Mechanism of Rubber-tea-chicken Agro-forestry Model in Tropical Area of China
7
作者 Meng Qingyan Miao Zewei Wang Zhaoqian 《Chinese Journal of Population,Resources and Environment》 2012年第3期100-106,共7页
As a typical tropical agro-forestry ecosystem in Wenchang, Hainan Province, China, rational mechanisms of the rubber-tea-chicken eco-agricultural model were studied with the Solow technological level index, stability ... As a typical tropical agro-forestry ecosystem in Wenchang, Hainan Province, China, rational mechanisms of the rubber-tea-chicken eco-agricultural model were studied with the Solow technological level index, stability indicator, harmonizing coefficient, grey corretation coefficient and production dominance. This study focused on rational hierarchical structure, the limiting factors and optimal strategies of the model development based on model structure, resource conditions and external market demands. Results showed that rational mechanism of the rubber-tea-chicken ecosystem model mainly included technological contributions, leverage function of dominance component (livestock husbandry), stability of the model structure and harmony of its components, the model dominant product's market demand and government's supporting policies. The contributions of fund, technology, information and talent resources played an important role in improving sustainability and productivity of the agro-forestry model. 展开更多
关键词 eco-agricultural model the Solow technological levelindex stability indicator harmonizing coefficient grey correlationcoefficient
下载PDF
Design and Validation of Strategy to Increasing the Rate Calving in Traditional Production System Livestock of Michoac^n M^xico Tropical Dry
8
作者 G. Salas E. Garcia +4 位作者 M. Perea R. Garciduefias E. Gutierrezl A. Caratachea J. P. Flores 《Journal of Agricultural Science and Technology(A)》 2011年第8期1204-1206,共3页
Michoacan brings 2.1% of national GDP, which is 12.5% to agriculture, Livestock is the fourth activity in economic importance in the State and develops in 43% of the territory (58,643 km:) using 27% of the populati... Michoacan brings 2.1% of national GDP, which is 12.5% to agriculture, Livestock is the fourth activity in economic importance in the State and develops in 43% of the territory (58,643 km:) using 27% of the population economically active. Michoacfin ranks third in national cattle inventory (1,608,523 heads) with fifth place in meat production (145,221 ton/year). The production model is extended cow-breed, subject to season and availability of food (few rains shortage of forage during drought), with 0.60 production of breed/cow/year, and a marked traditionalism in the form of production; also a high dependency to food based on the grazing. The inadequate national public policy expressed in the paternalism has limited the adoption of strategies to contribute to the solution of this problem. Therefore this study objective was to design and validate a strategy to increase the number of cow breeding/cow/year to season reproduction program, based on the use of synthetic progesterone "melengestrol acetate" (MGA) as a technology available, secure, easy to use, low cost and likely to be adoptable to the traditional model of production. Work was done in the dry tropics in the municipalities of Churumuco and Tzitzio, Michoacfin State, Mdxico. Used 133 bovine females with crossbreeding Bos indicus, diagnosed as not pregnant, 6.7 and 6.38 years old respectively for each municipality. Oral doses of 0.05 rag/day/cow of MGA during nine days then exposed to the presence of male. Data were analyzed using analysis of variance of a single way. The results indicate that the delivery rate was 58.33% in Churumuco and 61.86% in Tzitzio. This delivery rate represents an increase of 14%-16% of born per year considering that treated females become pregnant with traditional production system management. We concluded that the MGA is an appropriate strategy to the traditional production of tropical dry in MichoacO, n system that increases the rate of births and is likely to be accepted despite the paternalistic public policy prevailing in the country. 展开更多
关键词 Melengestol acetate Michoac/m tropic dry LIVESTOCK percentage of births
下载PDF
Energy Planning in Small Municipalities Based on Monitoring Results and Demand Side Management
9
作者 Dagnija Blumberga Andra Blumberga Marika Rosa Aiga Barisa 《Journal of Energy and Power Engineering》 2014年第3期453-460,共8页
Recent estimates state that the European Union is on course to achieve only half of the 20% energy consumption reduction target by 2020. As the first governmental stakeholders involved in the implementation of energy ... Recent estimates state that the European Union is on course to achieve only half of the 20% energy consumption reduction target by 2020. As the first governmental stakeholders involved in the implementation of energy saving initiatives, municipalities play a strategic role in the energy planning process. This paper focuses on establishment of an energy planning methodology for small municipalities with numbers of inhabitants in range of 1,000-10,000 which often face common problems associated with low efficient district heat supply systems and decreasing energy consumption in buildings. Particular attention is paid to DSM (demand side management) activities. DSM scheme includes legislative and financial flows with small investments from municipality side. Based on increased information and motivation it promotes reduction of energy consumption in all kinds of buildings. Practical experience has shown that application of DSM measures allows achieving 20% energy savings in municipal buildings during the first year. 展开更多
关键词 Demand side management energy efficiency energy planning.
下载PDF
Policies and Initiatives for Carbon Neutrality in Nordic Heating and Transport Systems
10
作者 Qiuwei Wu Jakob Glarbo Moiler Jacob Ostergaard Arne Hejde Nielsen 《Journal of Energy and Power Engineering》 2013年第9期1745-1753,共9页
Policies and initiatives promoting carbon neutrality in the Nordic heating and transport systems are presented. The focus within heating systems is the promotion of HPs (heat pumps) while the focus within transport ... Policies and initiatives promoting carbon neutrality in the Nordic heating and transport systems are presented. The focus within heating systems is the promotion of HPs (heat pumps) while the focus within transport systems is initiatives regarding EVs (electric vehicles). It is found that the conversion to HPs in the Nordic region relies on both private economic and national economic incentives. Initiatives toward carbon neutrality in the transport system are mostly concentrated on research, development and demonstration for deployment of a large number of EVs. All Nordic countries have plans for the future heating and transport systems with the ambition of realizing carbon neutrality. 展开更多
关键词 Policies and initiatives carbon neutrality heat pumps electric vehicles.
下载PDF
Robust reliable H_∞ control for a class of uncertain time-delay systems
11
作者 付艳明 张博 段广仁 《Journal of Harbin Institute of Technology(New Series)》 EI CAS 2009年第1期11-15,共5页
This paper deals with the problem of robust reliable H∞ control for a class of uncertain nonlinear systems with time-varying delays and actuator failures. The uncertainties in the system are norm-bounded and time-var... This paper deals with the problem of robust reliable H∞ control for a class of uncertain nonlinear systems with time-varying delays and actuator failures. The uncertainties in the system are norm-bounded and time-varying. Based on Lyapunov methods, a sufficient condition on quadratic stabilization independent of delay is obtained. With the help of LMIs (linear matrix inequalities) approaches, a linear state feedback controller is designed to quadratically stabilize the given systems with a H∞ performance constraint of disturbance attenuation for all admissible uncertainties and all actuator failures occurred within the prespecified subset. A numerical example is given to demonstrate the effect of the proposed design approach. 展开更多
关键词 time-delay systems robust H∞ control reliable control Lyapunov stability linear matrix inequalities actuator failures
下载PDF
Ecosystem assessment and protection effectiveness of a tropical rainforest region in Hainan Island, China 被引量:6
12
作者 翟俊 侯鹏 +3 位作者 曹巍 杨旻 蔡明勇 李静 《Journal of Geographical Sciences》 SCIE CSCD 2018年第4期415-428,共14页
Ecosystem services have become one of the core elements of ecosystem management and evaluation. As a key area of ecosystem services and for maintaining national ecological security, ecosystem changes and implementatio... Ecosystem services have become one of the core elements of ecosystem management and evaluation. As a key area of ecosystem services and for maintaining national ecological security, ecosystem changes and implementation effect evaluation are important in national key ecological function zones, for promoting the main function zone strategy and for improving the construction of an ecological civilization. This article studies the ecological zone of a tropical rainforest region in the central mountain area of Hainan Island, China. Multi-source satellite data and ground observation statistics are analyzed with geo-statistics method and ecological assessment model. The core analysis of this paper includes ecosystem patterns, quality and services. By means of spatial and temporal scale expansion and multidimensional space-time correlation analysis, the trends and stability characteristics of ecosystem changes are analyzed, and implementation effect evaluation is discussed. The analysis shows a variety of results. The proportion of forest area inside the ecological zone was significantly higher than the average level in Hainan Island. During 1990–2013, settlement gradually increased inside the ecological zone. After implementation of the zone in 2010, human activity intensity increased, with the main land use being urban construction and land reclamation. Water conservation in the ecological function zone was higher than that outside the zone. In general, it increased slightly, but had obvious fluctuations. Soil conservation inside the zone was also better than that outside. However, it demonstrated dramatic fluctuations and relatively poor stability during 1990–2013. The human disturbance index inside the zone was significantly lower than that outside, and had a lower biodiversity threat level. Especially in 2010–2013, the increased range of the human disturbance index inside the zone was significantly less than that outside. 展开更多
关键词 ecological function zone ecosystem ecosystem service protection effect
原文传递
Regional distribution and diurnal variation of deep convective systems over the Asian monsoon region 被引量:11
13
作者 WU XueKe QIE XiuShu YUAN Tie 《Science China Earth Sciences》 SCIE EI CAS 2013年第5期843-854,共12页
Using 12 years of data from the Tropical Rainfall Measuring Mission(TRMM)-based Precipitation Radar(PR),spatial and diurnal variations of deep convective systems(DCSs)over the Asian monsoon region are analyzed.The DCS... Using 12 years of data from the Tropical Rainfall Measuring Mission(TRMM)-based Precipitation Radar(PR),spatial and diurnal variations of deep convective systems(DCSs)over the Asian monsoon region are analyzed.The DCSs are defined by a 20 dBZ echo top extending 14 km.The spatial distribution of DCSs genesis is also discussed,with reference to the National Centers for Environmental Prediction(NCEP)reanalysis data.The results show that DCSs occur mainly over land.They concentrate in south of 20°N during the pre-monsoon season,and then move distinctly to mid-latitude regions,with the most active region on the south slope of the Himalayas during monsoon season.DCSs over the Tibetan Plateau are more frequent than those in central-eastern China,but smaller in horizontal scale and weaker in convective intensity.DCSs in central-eastern China have more robust updrafts and generate more lightning flashes than in other Asian monsoon regions.The horizontal scale of DCSs over the ocean is larger than that over the other regions,and the corresponding minimum infrared(IR)brightness temperature is lower,whereas the convective intensity is weaker.Continental DCSs are more common from noon through midnight,and DCSs over the Tibetan Plateau are more frequently from noon through evening.Oceanic DCSs frequency has a weaker diurnal cycle with dawn maximum,and diurnal variation of DCSs over the tropical maritime continent is consistent with that over the continent. 展开更多
关键词 deep convective systems Asian monsoon region TRMM regional distribution diurnal variation
原文传递
Late Triassic bivalves associated with a hydrothermal vent system in the Yidun Island Arc (SW China) of the eastern Tethys 被引量:2
14
作者 LIN Li ZHU LiDong +4 位作者 PANG YanChun SHA JinGeng Franz T. FURSICH FU XiuGen WANG XinLi 《Science China Earth Sciences》 SCIE EI CAS 2011年第12期1864-1870,共7页
The Yidun Island Arc in the Three Rivers (Jinsha River, Lancang River, Nujiang River) region of southwestern China is one of the most important Kuroko-type volcanogenic massive sulfide deposits (VMS) in China. Intra-a... The Yidun Island Arc in the Three Rivers (Jinsha River, Lancang River, Nujiang River) region of southwestern China is one of the most important Kuroko-type volcanogenic massive sulfide deposits (VMS) in China. Intra-arc rifting of Yidun Island occurred during the Late Carnian-Norian when VMS deposits such as the Gacun Pb-Zn-Cu deposit were formed. A bivalve fauna was found in fine-grained tuffaceous slate and in mineralized tuffaceous siltstone containing very high contents of Pb (45.01-103.37 ppm) and Zn (135.78-300.03 ppm) of the upper Tumugou Formation in the Changtai-Gacun volcanic-sedimentary rift basin. Stratigraphically, the bivalve-bearing beds are equivalents of the Gacun Pb-Zn-Cu deposits. The diversity of this bivalve fauna is very low. It consists mainly of the thin-shelled, epibyssate suspension-feeding bivalves Pergamidia eumenea and Parapergamidia changtaiensis, the burrowing large, elongated, suspension-feeding Trigonodus keuperinus and Unionites? sp., and occasional specimens of the endobyssate suspension-feeding Trigonodus? sp. and the deep burrowing suspension-feeding Pleuromya markiamensis. Individuals of the first four taxa are so abundant that the specimens are sometimes concentrated in shell beds, probably indicating a gregarious habit. This bivalve fauna is associated with internal moulds of cylindrical, slightly conical tubes most likely produced by a worm-shaped organism. Composition, morphology, diversity, and high abundance of this fauna, chemical features of the surrounding sediment, and the tectonic setting all suggest that this bivalve fauna lived in a deep-water environment in or around a hydrothermal vent system. 展开更多
关键词 Late Triassic hydrothermal vents bivalves Yidun Island Arc of the eastern Tethys
原文传递
Microbial Biomass Dynamics in a Tropical Agroecosystem: Influence of Herbicide and Soil Amendments 被引量:3
15
作者 Alka SINGH Mahesh Kumar SINGH Nandita GHOSHAL 《Pedosphere》 SCIE CAS CSCD 2016年第2期257-264,共8页
The influences of herbicide alone and in combination with the soil amendments with contrasting resource qualities on dynamics of soil microbial biomass C (MBC), N (MBN), and P (MBP) were studied through two annu... The influences of herbicide alone and in combination with the soil amendments with contrasting resource qualities on dynamics of soil microbial biomass C (MBC), N (MBN), and P (MBP) were studied through two annual cycles in rice-wheat-summer fallow crop sequence in a tropical dryland agroecosystem. The experiment included application of herbicide (butachlor) alone or in combination with various soil amendments having equivalent amount of N in the forms of chemical fertilizer, wheat straw, Sesbania aculeata, and farm yard manure (FYM). Soil microbial biomass showed distinct temporal variations in both crop cycles, decreased from vegetative to grain-forming stage, and then increased to maximum at crop maturity stage. Soil MBC was the highest in herbicide + Sesbania aculeata treatment followed by herbicide + FYM, herbicide + wheat straw, herbicide + chemical fertilizer, and herbicide alone treatments in decreasing order during the rice-growing period. During wheat-growing period and summer fallow, soil MBC attained maximum for herbicide + wheat straw treatment whereas herbicide + FYM, herbicide + Sesbania, and herbicide + chemical fertilizer treatments showed similar levels. The overall trend of soil MBN was similar to those of soil MBC and MBP except that soil MBN was higher in herbicide + chemical fertilizer treatment over the herbicide + wheat straw treatment during rice-growing period. In spite of the addition of equivalent amount of N through exogenous soil amendments in combination with the herbicide, soil microbial biomass responded differentially to the treatments. The resource quality of the amendments had more pronounced impact on the dynamics of soil microbial biomass, which may have implications for long-term sustainability of rainfed agroecosystems in dry tropics. 展开更多
关键词 chemical fertilizer farmyard manure organic amendment Sesbania aculeata wheat straw
原文传递
上一页 1 下一页 到第
使用帮助 返回顶部