期刊文献+
共找到4,596篇文章
< 1 2 230 >
每页显示 20 50 100
Infiltration,runoff,and slope stability behaviors of infinite slope with macropores based on an improved Green–Ampt model
1
作者 LI Shanghui WU Guoxiong +2 位作者 QUE Yun JIANG Zhenliang CHENG Gaoyun 《Journal of Mountain Science》 SCIE CSCD 2024年第7期2220-2235,共16页
Infiltration–runoff–slope instability mechanism of macropore slope under heavy rainfall is unclear.This paper studied its instability mechanism with an improved Green–Ampt(GA)model considering the dual-porosity(i.e... Infiltration–runoff–slope instability mechanism of macropore slope under heavy rainfall is unclear.This paper studied its instability mechanism with an improved Green–Ampt(GA)model considering the dual-porosity(i.e.,matrix and macropore)and ponding condition,and proposed the infiltration equations,infiltration–runoff coupled model,and safety factor calculation method.Results show that the infiltration processes of macropore slope can be divided into three stages,and the proposed model is rational by a comparative analysis.The wetting front depth of the traditional unsaturated slope is 17.2%larger than that of the macropore slope in the early rainfall stage and 27%smaller than that of the macropore slope in the late rainfall stage.Then,macropores benefit the slope stability in the early rainfall but not in the latter.Macropore flow does not occur initially but becomes pronounced with increasing rainfall duration.The equal depth of the wetting front in the two domains is regarded as the onset criteria of macropore flow.Parameter analysis shows that macropore flow is delayed by increasing proportion of macropore domain(ω_(f)),whereas promoted by increasing ratio of saturated permeability coefficients between the two domains(μ).The increasing trend of ponding depth is sharp at first and then grows slowly.Finally,when rainfall duration is less than 3 h,ωf andμhave no significant effect on the safety factor,whereas it decreases with increasingωf and increases with increasingμunder longer duration(≥3 h).With the increase ofω_(f),the slope maximum instability time advances by 10.5 h,and with the increase ofμ,the slope maximum instability time delays by 3.1 h. 展开更多
关键词 Macropore slope green–Ampt infiltration model Equivalent wetting front Ponding response time Slope stability
下载PDF
Evaluation of Green Development Efficiency in Chongqing Municipality Based on Super-SBM and Malmquist Models
2
作者 Zhang Yuefang 《Contemporary Social Sciences》 2023年第5期44-58,共15页
The green development of Chongqing municipality is crucial in establishing a major ecological shield in the upper reaches of the Yangtze River.By developing a Super-SBM model and using the Malmquist index to analyze a... The green development of Chongqing municipality is crucial in establishing a major ecological shield in the upper reaches of the Yangtze River.By developing a Super-SBM model and using the Malmquist index to analyze and calculate the green development efficiency and its influencing factors in Chongqing from 2011 to 2021,this study reveals an accelerating trend in the overall green development efficiency in Chongqing.The significant enhancement of green development efficiency in Chongqing is primarily attributed to changes in returns to scale.Pure technical efficiency and technological advancements have a considerable potential impact on improving green development efficiency in Chongqing.Furthermore,there are discernible disparities in green development efficiency among districts and counties in Chongqing,with different factors influencing these variations.Chongqing is suggested to promote clean and efficient energy utilization,bolster the application and commercialization of scientific and technological advancements,consistently advance ecological restoration and management,and elevate the quality of green development to a higher level. 展开更多
关键词 CHONGQING green development efficiency SUPER-EFFICIENCY SBMMalmquist model
下载PDF
Green Roof Performance for Stormwater Management in Equatorial Urban Areas Using Storm Water Management Model (SWMM)
3
作者 King Kuok Kuok Po Chan Chiu +2 位作者 Mei Yun Chin Md. Rezaur Rahman Muhammad Khusairy Bakri 《Journal of Water Resource and Protection》 2023年第12期706-720,共15页
Many Low Impact Developments (LIDs) have recently been developed as a sustainable integrated strategy for managing the quantity and quality of stormwater and surrounding amenities. Previous research showed that green ... Many Low Impact Developments (LIDs) have recently been developed as a sustainable integrated strategy for managing the quantity and quality of stormwater and surrounding amenities. Previous research showed that green roof is one of the most promising LIDs for slowing down rainwater, controlling rainwater volume, and enhancing rainwater quality by filtering and leaching contaminants from the substrate. However, there is no guideline for green roof design in Malaysia. Hence, Investigating the viability of using green roofs to manage stormwater and address flash flood hazards is urgently necessary. This study used the Storm Water Management Model (SWMM) to evaluate the effectiveness of green roof in managing stormwater and improving rainwater quality. The selected study area is the multistory car park (MSCP) rooftop at Swinburne University of Technology Sarawak Campus. Nine green roof models with different configurations were created. Results revealed that the optimum design of a green roof is 100 mm of berm height, 150 mm of soil thickness, and 50 mm of drainage mat thickness. With the ability to reduce runoff generation by 26.73%, reduce TSS by 89.75%, TP by 93.07%, TN by 93.16%, and improved BOD by 81.33%. However, pH values dropped as low as 5.933 and became more acidic due to the substrates in green roof. These findings demonstrated that green roofs improve water quality, able to temporarily store excess rainfall and it is very promising and sustainable tool in managing stormwater. 展开更多
关键词 green Roof Low Impact Development (LID) Storm Water Management model (SWMM) Storage Capacity Pollutants Removal
下载PDF
多层非均质边坡降雨入渗分析的改进Green-Ampt模型
4
作者 蒋水华 刘贤 +1 位作者 黄劲松 周创兵 《岩土工程学报》 EI CAS CSCD 北大核心 2024年第6期1177-1186,共10页
边坡降雨入渗分析对于降雨型滑坡加固设计、治理和风险防控至关重要。经典的Green-Ampt模型参数虽然具有明确的物理意义,计算便捷,但是忽略了入渗区客观存在的过渡层,并且不能有效分析考虑土体渗透系数空间变异性的多层非均质边坡降雨... 边坡降雨入渗分析对于降雨型滑坡加固设计、治理和风险防控至关重要。经典的Green-Ampt模型参数虽然具有明确的物理意义,计算便捷,但是忽略了入渗区客观存在的过渡层,并且不能有效分析考虑土体渗透系数空间变异性的多层非均质边坡降雨入渗问题。为此,提出了一种适用于多层非均质边坡降雨入渗分析的改进Green-Ampt模型,考虑了降雨入渗的椭圆形过渡层,推导了不同降雨历时下边坡含水率分布情况。同时,以无限长边坡模型为例,通过4种常见的边坡工况验证了该模型的有效性,并进行了降雨入渗条件下非均质边坡稳定性分析。结果表明:对于设定的4种工况,提出的改进Green-Ampt模型计算的边坡体积含水量分布、安全系数和滑动面深度与Richards方程数值解吻合,而基于修正Green-Ampt模型计算的边坡体积含水量和滑动面分布存在偏差,边坡安全系数偏小。此外,基于提出的改进Green-Ampt模型能够准确识别最危险滑动面位置。研究成果可为多层非均质边坡降雨入渗分析及降雨型滑坡加固设计及风险防控提供理论参考。 展开更多
关键词 非均质边坡 降雨入渗 稳定性分析 改进green-Ampt模型 空间变异性
下载PDF
Dynamic evaluation of digital and green development policies based on text mining of the PMC framework
5
作者 Ye Chunmei Wu Lihua 《Journal of Southeast University(English Edition)》 EI CAS 2024年第3期319-326,共8页
Aiming to identify policy topics and their evolutionary logic that enhance the digital and green development(dual development)of traditional manufacturing enterprises,address weaknesses in current policies,and provide... Aiming to identify policy topics and their evolutionary logic that enhance the digital and green development(dual development)of traditional manufacturing enterprises,address weaknesses in current policies,and provide resources for refining dual development policies,a total of 15954 dual development-related policies issued by national and various departmental authorities in China from January 2000 to August 2023 were analyzed.Based on topic modeling techniques and the policy modeling consistency(PMC)framework,the evolution of policy topics was visualized,and a dynamic assessment of the policies was conducted.The results show that the digital and green development policy framework is progressively refined,and the governance philosophy shifts from a“regulatory government”paradigm to a“service-oriented government”.The support pattern evolves from“dispersed matching”to“integrated symbiosis”.However,there are still significant deficiencies in departmental cooperation,balanced measures,coordinated links,and multi-stakeholder participation.Future policy improvements should,therefore,focus on guiding multi-stakeholder participation,enhancing public demand orientation,and addressing the entire value chain.These steps aim to create an open and shared digital industry ecosystem to promote the coordinated dual development of traditional manufacturing enterprises. 展开更多
关键词 digital and green development text mining topic modeling policy modeling consistency(PMC)framework machine learning
下载PDF
Synergistic dance of digital economy and green finance on carbon emissions:Insights from China
6
作者 Ruiqi Wang Wenqi Zhao 《Chinese Journal of Population,Resources and Environment》 2024年第3期213-229,共17页
China has recently implemented a dual-carbon strategy to combat climate change and other environmental issues and is committed to modernizing it sustainably.This paper supports these goals and explores how the digital... China has recently implemented a dual-carbon strategy to combat climate change and other environmental issues and is committed to modernizing it sustainably.This paper supports these goals and explores how the digital economy and green finance intersect and impact carbon emissions.Using panel data from 30 Chinese provinces over the period 2011-2021,this paper finds that the digital economy and green finance can together reduce carbon emissions,and conducts several robustness tests supporting this conclusion.A heterogeneity analysis shows that these synergistic effects are more important in regions with low levels of social consumption Meanwhile,in the spatial dimension,the synergistic effect of the local digital economy and green finance adversely impacts the level of carbon emissions in surrounding areas.The findings of this paper provide insights for policymakers in guiding capital flow and implementing carbon-reduction policies while fostering the growth of China’s digital economy and environmental sustainability. 展开更多
关键词 Digital economy green finance Carbon emission Dynamic spatial Durbin model Spatial spillover effect
下载PDF
Moderating effect of corporate financialization on the impact of climate policy on corporate green innovation:Evidence from China
7
作者 Chao Tu Zhilong Qin Qingqing Yang 《Chinese Journal of Population,Resources and Environment》 2024年第3期230-240,共11页
With intensifying global climate change,humanity is confronted with unparalleled environmental challenges and risks.This study employs the staggered difference-in-difference model to examine the relationship between c... With intensifying global climate change,humanity is confronted with unparalleled environmental challenges and risks.This study employs the staggered difference-in-difference model to examine the relationship between climate policy and green innovation in the corporate financialization context.Using Chinese-listed company data from 2008 to 2020,our analysis reveals a favorable correlation between China’s carbon emission trading policy(CCTP)and advancements in green innovation.Furthermore,we find that the level of corporate financialization moderates this correlation,diminishing the driving effect of CCTP on green innovation.Additionally,results of heterogeneity analysis show that this moderating consequence is more evident in non-state owned and low-digitization enterprises compared with state-owned and high-digitization ones.Our findings contribute to the existing literature by clarifying the interaction between CCTP,green innovation,and corporate financialization.Our research provides valuable insights for policymakers and stakeholders seeking to strengthen climate policies and encourages green innovation in different types of businesses. 展开更多
关键词 Staggered DID model China’s carbon emission trading policy green innovation Corporate financialization DIGITALIZATION
下载PDF
Peritoneal fluid indocyanine green test for diagnosis of gut leakage in anastomotic leakage rats and colorectal surgery patients
8
作者 Yu Huang Tian-Yang Li +4 位作者 Jie-Feng Weng Hui Liu Yu-Jie Xu Shuai Zhang Wei-Li Gu 《World Journal of Gastrointestinal Surgery》 SCIE 2024年第6期1825-1834,共10页
BACKGROUND Application of indocyanine green(ICG)fluorescence has led to new developments in gastrointestinal surgery.However,little is known about the use of ICG for the diagnosis of postoperative gut leakage(GL).In a... BACKGROUND Application of indocyanine green(ICG)fluorescence has led to new developments in gastrointestinal surgery.However,little is known about the use of ICG for the diagnosis of postoperative gut leakage(GL).In addition,there is a lack of rapid and intuitive methods to definitively diagnose postoperative GL.AIM To investigate the effect of ICG in the diagnosis of anastomotic leakage in a surgical rat GL model and evaluate its diagnostic value in colorectal surgery patients.METHODS Sixteen rats were divided into two groups:GL group(n=8)and sham group(n=8).Approximately 0.5 mL of ICG(2.5 mg/mL)was intravenously injected postoperatively.The peritoneal fluid was collected for the fluorescence test at 24 and 48 h.Six patients with rectal cancer who had undergone laparoscopic rectal cancer resection plus enterostomies were injected with 10 mL of ICG(2.5 mg/mL)on postoperative day 1.Their ostomy fluids were collected 24 h after ICG injection to identify the possibility of the ICG excreting from the peripheral veins to the enterostomy stoma.Participants who had undergone colectomy or rectal cancer resection were enrolled in the diagnostic test.The peritoneal fluids from drainage were collected 24 h after ICG injection.The ICG fluorescence test was conducted using OptoMedic endoscopy along with a near-infrared fluorescent imaging system.RESULTS The peritoneal fluids from the GL group showed ICG-dependent green fluorescence in contrast to the sham group.Six samples of ostomy fluids showed green fluorescence,indicating the possibility of ICG excreting from the peripheral veins to the enterostomy stoma in patients.The peritoneal fluid ICG test exhibited a sensitivity of 100%and a specificity of 83.3%for the diagnosis of GL.The positive predictive value was 71.4%,while the negative predictive value was 100%.The likelihood ratios were 6.0 for a positive test result and 0 for a negative result.CONCLUSION The postoperative ICG test in a drainage tube is a valuable and simple technique for the diagnosis of GL.Hence,it should be employed in clinical settings in patients with suspected GL. 展开更多
关键词 Gut leakage Indocyanine green Anastomotic leakage model Diagnostic test Diagnostic technique
下载PDF
Are cities greener because of innovation?Independent innovation policy and green economic efficiency
9
作者 Zhuoji Zheng Xueqin Li +3 位作者 Mengjie Yu Yuan Li Xianfeng Han Yuping Yin 《Chinese Journal of Population,Resources and Environment》 2024年第2期118-126,共9页
The national independent innovation demonstration zone(NIIDZ)is an independent innovation policy that plays a crucial role in implementing strategies.Given the importance of the NIIDZ,this study uses panel data of 278... The national independent innovation demonstration zone(NIIDZ)is an independent innovation policy that plays a crucial role in implementing strategies.Given the importance of the NIIDZ,this study uses panel data of 278 prefecture-level cities in China from 2006 to 2020 and empirically examines the effect and internal mechanism of the NIIDZ on green economic efficiency(GEE)using the difference-in-difference model(DID).The results show that the NIIDZ effectively enhances the growth of GEE,and the results remain valid through several robustness tests,such as year-by-year propensity score matching.The transmission mechanism suggests that the NIIDZ indirectly drives GEE by accelerating scientific and technological investment,promoting talent concentration,and optimizing the industrial structure.Moreover,heterogeneity analysis reveals that the promotion effect of the NIIDZ on GEE is more prominent in the eastern region and high green development level areas.The study’s findings can serve as a reference for China to further utilize the policy effectiveness of the NIIDZ and accelerate the high-quality development of the green economy in the future. 展开更多
关键词 National innovation independent demonstration Zone(NIIDZ) green economy efficiency(GEE) Difference-in-difference model(DID)
下载PDF
How R&D investment promotes green technology innovation in the context of digitalization?-An empirical analysis based on provincial panel data
10
作者 LIU Jie LI Zhi-hui WEI Fang-xin 《Ecological Economy》 2024年第1期39-52,共14页
Green technology innovation is an important driving force and source to promote my country’s high-quality development,and it is the core path to achieve sustainable development.This paper uses my country’s provincia... Green technology innovation is an important driving force and source to promote my country’s high-quality development,and it is the core path to achieve sustainable development.This paper uses my country’s provincial panel data from 2016 to 2019 to study the impact mechanism of R&D investment on green technology innovation,and introduces the level of digitization,using the panel threshold model to discuss its role in the impact mechanism of R&D investment on green technology innovation.The study found that when the level of digitalization in a region is low,increasing R&D investment does not necessarily improve the ability of green technology innovation;when the level of digitalization is relatively high,R&D investment has a positive role in promoting green technology innovation.Therefore,it is necessary to improve policies to encourage enterprises to increase investment in research and development;at the same time,it is necessary to promote the coordinated development of digital foundation,digital investment,digital literacy,digital economy and digital application,and promote the deep integration of digitalization and green technology innovation. 展开更多
关键词 green technology innovation R&D investment digital level panel model
下载PDF
Evaluating Model Effectiveness for Soil Infiltration Attribute: Comparison of Green-Ampt, Horton and Modified Green-Ampt Infiltration Models
11
作者 Mosammat Mustari Khanaum Md. Saidul Borhan 《Journal of Geoscience and Environment Protection》 2023年第2期57-68,共12页
Soil infiltration is a very important concept in hydrology as well as irrigation, which plays a vital role in estimating surface runoff and groundwater recharge. It is a complicated process that varies with numerous f... Soil infiltration is a very important concept in hydrology as well as irrigation, which plays a vital role in estimating surface runoff and groundwater recharge. It is a complicated process that varies with numerous factors. Accurate estimation of soil infiltration is required for future irrigation, and many other purposes. To estimate the infiltration process, there are numerous models. The majority of them have some presumptions, a unique calculation method, and some limitations. The purpose of the paper was to assess the model’s performance for a similar hypothetical scenario involving soil infiltration. It compared the infiltration rate, runoff rate, and incremental infiltration versus time for three different infiltration models: the Green-Ampt model (GA), the Horton model and the Modified Green-Ampt (MGA) model. A spreadsheet was used to calculate the Horton model, and HYDROL-INF (V 5.03) was used to simulate the other two models. Among those three models, the MGA model outperformed those three models, while the GA model produced greater infiltration rate than rainfall, which was insensible. The study showed that the MGA model, which provides useful infiltration predictions, outperformed the other two infiltration models. Since the Horton model does not consider ponding conditions, it is only applicable when the effective rainfall intensity exceeds the final infiltration capacity. Moreover, the GA model’s initial infiltration rate is irrational because it disregards the intensity of the rainfall. The results of this study will assist in selecting the most accurate method for estimating soil infiltration for agricultural purposes. 展开更多
关键词 INFILTRATION Groundwater Recharge green-Ampt Horton model Modified green-Ampt
下载PDF
Modification of the Leontief-Ford Input-Output Model for the Green Economy Goals and Environment Protection
12
作者 Ivan Potravny Andrey Gusev +1 位作者 Vasily Stoykov Violetta Gassiy 《Journal of Geoscience and Environment Protection》 2017年第11期15-23,共9页
The economics’ ecological modernization approach based on the input-output balance model is considered in the paper. The government measures on Russian Federation’s transition to green economy on reducing of greenho... The economics’ ecological modernization approach based on the input-output balance model is considered in the paper. The government measures on Russian Federation’s transition to green economy on reducing of greenhouse gas emissions are analyzed. In an article for green economy evaluation, including greenhouse gas emissions per capita and per unit of GDP, the indicator of the production environmental costs is proposed to include. The authors suppose adding and to modernize the Leontief-Ford model of input-output balance by economic evaluation of the environment pollution effects. This model is proposed to consider macro-economic assessment of environmental damage, health deterioration due to environmental pollution, as well as the use costs of the environmentally friendly technologies, the environmental and energy innovations’ implementation, climate change. The proposed modified model of environmentally oriented input-output balance can be used in the economic compensation system implementation on natural capital use and ecosystem services’ consuming in countries and their regions. The modified Leontief-Ford model proposed in the paper can be used for green economy development calculating, for example in Russia during the development of measures for the environment and economic development. Also this paper opens discussions for opportunities of the further possible integration of the theoretical models for environment protection decision-making. 展开更多
关键词 ECOLOGICAL MODERNIZATION of ECONOMY ECONOMIC Loss Environmental POLLUTION green ECONOMY Leontief-Ford model
下载PDF
A Study of the Impact of the Digital Economy on the Efficiency of Urban Green Economy--Based on the Yangtze River Delta City Cluster
13
作者 LU Yang MIN Tianwei 《Management Studies》 2024年第1期1-8,共8页
This paper adopts the non-expected output-super-efficiency SBM(Slacks-Based Model)model and principal component analysis to calculate the green economy efficiency and the digital economy level of 27 prefecture-level c... This paper adopts the non-expected output-super-efficiency SBM(Slacks-Based Model)model and principal component analysis to calculate the green economy efficiency and the digital economy level of 27 prefecture-level cities in China’s Yangtze River Delta urban agglomeration between 2011 and 2019,respectively,and examines the impact of the digital economy on the green economy efficiency by using benchmark regression and mechanism analysis.The findings show that,first,the digital economy has a significant contribution to the green economic efficiency of cities,and this conclusion still holds after robustness tests such as replacing explanatory and interpreted variables and introducing province-fixed effects.Second,through the mechanism test,it is found that the digital economy can indirectly promote urban green economic efficiency through the positive mechanism effect of promoting industrial structure upgrading. 展开更多
关键词 digital economy urban green economy efficiency undesired output-super-efficiency SBM model
下载PDF
和美乡村视角下的苏南农田“GREEN”水环境治理模式应用研究
14
作者 莫宇辰 李永钧 +1 位作者 逯星辉 魏家星 《园林》 2024年第6期51-60,共10页
随着中国宜居宜业和美乡村建设的不断深入,乡村水环境的治理与保护作为乡村生态文明建设的重要组成部分日益受到社会的重视和关注。在以往大规模灰色基础设施建设的背景下,乡村忽略了对于水生态绿色基础设施的构建,生态格局趋于破碎。... 随着中国宜居宜业和美乡村建设的不断深入,乡村水环境的治理与保护作为乡村生态文明建设的重要组成部分日益受到社会的重视和关注。在以往大规模灰色基础设施建设的背景下,乡村忽略了对于水生态绿色基础设施的构建,生态格局趋于破碎。农田空间作为农业面源污染的重要源头,结合多学科视角探索农田水环境污染治理新模式具有高度的必要性。立足于苏南地区独特的农田水网体系,紧密结合农业空间生产属性,研究现有农田水环境治理理论方法与实际建设,提炼以“源头绿色—过程净化—末端吸收—生态保育—循环回用”的苏南农田“GREEN”水环境治理模式,探索风景园林学科水治理方法在农田沟渠、河道及湿地等乡村空间的运用路径,并以常州市中天黄金大农场总体规划为例进行实践应用。推动风景园林学科于乡村生产空间的应用模式探索,为未来农业面源污染防治提供参考借鉴。 展开更多
关键词 和美乡村 乡村水环境 农业面源污染 农田水环境治理 green”治理模式 常州市中天黄金大农场
下载PDF
SOLVABILITY RESULTS OF A CONDITIONAL INPUT-OUTPUT EQUATION BASED ON A TYPE OF NONLINEAR LEONTIEF MODEL
15
作者 胡问鸣 刘颖范 沙春林 《Transactions of Nanjing University of Aeronautics and Astronautics》 EI 2003年第2期224-229,共6页
A class of nonlinear and continuous type Leontief model and its corresponding conditional input-output equation are introduced, and two basic problems under the so called positive or negative boundary assumption are p... A class of nonlinear and continuous type Leontief model and its corresponding conditional input-output equation are introduced, and two basic problems under the so called positive or negative boundary assumption are presented. By approaches of nonlinear analysis some solvability results of this equation and continuous perturbation properties of the relative solution sets are obtained, and some economic significance are illustrated by the remark. 展开更多
关键词 conditional Leontief model input-output equation positive (negative) boundary assumption nonlinear analysis SOLVABILITY continuous disturbance
下载PDF
Numerical simulation of residual stress field in green power metallurgy compacts by modified Drucker-Prager Cap model 被引量:6
16
作者 周蕊 张连洪 +1 位作者 何柏岩 刘玉红 《Transactions of Nonferrous Metals Society of China》 SCIE EI CAS CSCD 2013年第8期2374-2382,共9页
Compaction process simulation and residual stress prediction of green PM compact were carried out with elasto-plastic 3D FEA based on the modified Drueker-Prager Cap model in Abaqus. The model parameters of the invest... Compaction process simulation and residual stress prediction of green PM compact were carried out with elasto-plastic 3D FEA based on the modified Drueker-Prager Cap model in Abaqus. The model parameters of the investigated powder Distaloy AE were determined as functions of relative density through typical mechanical property tests of powder. The model was implemented as a user subroutine USDFLD. Single sided compaction of a d20 ram^5 mm disk green compact of Distaloy AE was simulated, and the residual stress of the disk after ejection was predicted with FEA. The FEA results of the compaction process and the residual stress of the disk show good agreement with compaction experiments and X-ray diffraction measurements, which validates the model and its parameters. The results indicate that the compressive residual stresses exist mainly in a thin layer on the side surface, but the residual stresses are very small on the top and bottom surfaces. 展开更多
关键词 residual stress green compacts numerical simulation modified Drucker-Prager Cap model
下载PDF
边坡植被恢复中考虑微生物矿化和植被作用的Green-Ampt模型 被引量:1
17
作者 李旭 高山 +3 位作者 周成 王一冰 钟启明 陈群 《岩土工程学报》 EI CAS CSCD 北大核心 2023年第9期1953-1962,共10页
在边坡植被恢复中降雨入渗量的估算是很重要的,为探究石漠化边坡格构内微生物矿化联合植被作用的填土降雨入渗过程,在传统Green-Ampt模型基础上,针对表层矿化的土柱引入稳定入渗率,提出考虑微生物表层矿化(M)作用的改进G-A模型(M-G-A);... 在边坡植被恢复中降雨入渗量的估算是很重要的,为探究石漠化边坡格构内微生物矿化联合植被作用的填土降雨入渗过程,在传统Green-Ampt模型基础上,针对表层矿化的土柱引入稳定入渗率,提出考虑微生物表层矿化(M)作用的改进G-A模型(M-G-A);针对含植株土柱,考虑复合土层的入渗过程,分别提出考虑植被(P)作用的改进G-A模型(P-G-A)以及考虑微生物矿化联合植被作用的改进G-A模型(PM-G-A)。利用改进G-A模型进行累计入渗量计算,并将计算结果与土柱试验实测值、Hydrus数值解进行对比分析。结果表明:M-G-A模型可以较好地描述累计入渗量随时间的变化,且矿化程度越高模型计算偏差越小,在强矿化作用下误差可控制在5%以内;P-G-A模型的计算误差随降雨历时而增加,但相较于Hydrus数值解可以减少误差约10%;PM-G-A模型的计算偏差随降雨历时呈现先增加后减小的趋势,总体上优于Hydrus数值解。改进G-A模型能够针对微生物表层矿化石漠化边坡格构内填土的生态恢复技术进行累计入渗量即蓄水量分析,具有一定的工程实用价值。 展开更多
关键词 边坡植被恢复 降雨入渗 植株孔优先流 微生物表层矿化 green-Ampt模型解析解 数值计算
下载PDF
Indocyanine green clearance test and model for end-stage liver disease score of patients with liver cirrhosis 被引量:37
18
作者 Sheng, Qin-Song Lang, Ren +3 位作者 He, Qiang Yang, Yong-Jiu Zhao, De-Fang Chen, Da-Zhi 《Hepatobiliary & Pancreatic Diseases International》 SCIE CAS 2009年第1期46-49,共4页
BACKGROUND: The indocyanine green (ICG) clearance test (clearance rate (K) and retention rate at 15 minutes (R(15))) is a sensitive indicator to evaluate liver function. The model for end-stage liver disease (MELD) sc... BACKGROUND: The indocyanine green (ICG) clearance test (clearance rate (K) and retention rate at 15 minutes (R(15))) is a sensitive indicator to evaluate liver function. The model for end-stage liver disease (MELD) score has emerged as a useful tool for estimating the mortality of patients awaiting liver transplantation and has recently been validated on patients with liver diseases of various etiologies and severity. In this study, we investigated the correlation between the ICG clearance test and MELD score of patients with liver cirrhosis. METHODS: From June 2007 to March 2008, 52 patients with liver cirrhosis admitted to our center were classified into Child-Pugh class A (8 patients), B (14) and C (30). The ICG clearance test (K value and R(15)) was performed by ICG pulse spectrophotometry (DDG-3300K), and the MELD scores of patients were calculated. RESULTS: As the Child-Pugh classification of liver function gradually deteriorated, the K value decreased, while R(15) and MELD score increased. There were significant statistical differences in K value, R(15) and MELD score in patients with different Child-Pugh classifications. Significant correlations were found between the parameters of the ICG clearance test (K value and R(15)) and MELD score. A negative correlation was observed between K value and MELD score (r=-0.892, P < 0.05), while a positive correlation was observed between R(15) and MELD score (r=0.804, P < 0.05). CONCLUSIONS: The ICG clearance test and MELD score are good parameters for evaluating liver function. Moreover, K value and R(15) have significant correlations with MELD score, especially the K value, which may be a convenient and appropriate indicator to evaluate liver function of patients with liver cirrhosis. 展开更多
关键词 liver function tests indocyanine green model for end-stage liver disease SPECTROPHOTOMETRY
下载PDF
A Decision-Making Framework Model of Cutting Fluid Selection for Green Manufacturing and the Case Study 被引量:5
19
作者 TAN Xian-chun 1, LIU Fei 1, CAO Hua-jun 1, ZHANG Hua 2 (1. The Institute of Manufacturing Engineering, Chongqing University, Chongqing 400044, China 2. School of Manufacturing & Automation, Wuhan University of Science & Technol ogy, Wuhan 430081, China) 《厦门大学学报(自然科学版)》 CAS CSCD 北大核心 2002年第S1期136-137,共2页
Pursuing the green manufacturing (GM) of products i s very beneficial in the alleviation of environment burdens. In order to reap such benefits, green manufacturing is involved in every aspect of manufacturing proc es... Pursuing the green manufacturing (GM) of products i s very beneficial in the alleviation of environment burdens. In order to reap such benefits, green manufacturing is involved in every aspect of manufacturing proc esses. During the machining process, cutting fluid is one of the main roots of e nvironmental pollution. And how to make an optimal selection for cutting fluid f or GM is an important path to reduce the environmental pollution. The objective factors of decision-making problems in the traditional selection of cutting flu id are usually two: quality and cost. But from the viewpoint of GM, environmenta l impact (E) should be considered together. In this paper, a multi-object d ecision-making model of cutting fluid selection for GM is put forward, in which the objects of Quality (Q), Cost(C) and Environmental impact (E) are considered together. In this model, E means to minimize the environmental impact, Q means to maximize the quality and C means to minimize the cost. Each objective is anal yzed in detail too. A case study on a decision-making problem of cutting fluid selection in a gear hobbing process is analyzed, and the result shows the model is practical. 展开更多
关键词 green manufacturing cutting fluid decision-mak ing model environmental impact
下载PDF
A Climatic Sequence Stratigraphic Model in the Terrestrial Lacustrine Basin:A Case Study of Green River Formation,Uinta Basin,USA 被引量:4
20
作者 WANG Junling ZHENG Herong +3 位作者 XIAO Huanqin ZHONG Guohong Ronald STEEL YIN Peigui 《Acta Geologica Sinica(English Edition)》 SCIE CAS CSCD 2009年第1期130-135,共6页
In recent years, with the development of terrestrial sequence stratigraphy, more attention has been focused on the study of the terrestrial lacustrine sequence stratigraphic model globally. Different viewpoints are pr... In recent years, with the development of terrestrial sequence stratigraphy, more attention has been focused on the study of the terrestrial lacustrine sequence stratigraphic model globally. Different viewpoints are preferred by researchers. Under the guidance of the theory of sequence stratigraphy, the findings of this paper indicate that climate is a major factor controlling the formation of the fourth-order sequence, based upon the study of the sequence stratigraphy in the Green River Formation of the Uinta basin in the USA. It also divides the fourth-order sequence in the terrestrial lacustrine basin into two system tracts: the wet (rising) half-cycle and the dry (falling) half- cycle, establishing a new-style fourth-order sequence stratigraphic model for the terrestrial lacustrine basin, that is, the climate-genetic sequence stratigraphic model. As a result, the theory of sequence stratigraphy is greatly enriched. 展开更多
关键词 CLIMATE fourth-order sequence sequence stratigraphic model terrestrial lacustrine basin green River Formation Uinta basin
下载PDF
上一页 1 2 230 下一页 到第
使用帮助 返回顶部