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A 48-bp deletion upstream of LIGULELESS 1 alters rice panicle architecture
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作者 Linhua Wu Min Hu +6 位作者 Shuwei Lyu Wenfeng Chen Hang Yu Qing Liu Wei He Chen Li Zuofeng Zhu 《The Crop Journal》 SCIE CSCD 2024年第2期354-363,共10页
Panicle architecture is an agronomic determinant of crop yield and a target for cereal crop improvement.To investigate its molecular mechanisms in rice,we performed map-based cloning and characterization of OPEN PANIC... Panicle architecture is an agronomic determinant of crop yield and a target for cereal crop improvement.To investigate its molecular mechanisms in rice,we performed map-based cloning and characterization of OPEN PANICLE 1(OP1),a gain-of-function allele of LIGULELESS 1(LG1),controlling the spread-panicle phenotype.This allele results from a 48-bp deletion in the LG1 upstream region and promotes pulvinus development at the base of the primary branch.Increased OP1 expression and altered panicle phenotype in chimeric transgenic plants and upstream-region knockout mutants indicated that the deletion regulates spread-panicle architecture in the mutant spread panicle 1(sp1).Knocking out BRASSINOSTEROID UPREGULATED1(BU1)gene in the background of OP1 complementary plants resulted in compact panicles,suggesting OP1 may regulate inflorescence architecture via the brassinosteroid signaling pathway.We regard that manipulating the upstream regulatory region of OP1 or genes involved in BR signal pathway could be an efficient way to improve rice inflorescence architecture. 展开更多
关键词 upstream region Panicle architecture Gene expression BR Rice
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Climate-Vegetation Coverage Interactions in the Hengduan Mountains Area, Southeastern Tibetan Plateau, and Their Downstream Effects
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作者 Congxi FANG Jinlei CHEN +4 位作者 Chaojun OUYANG Lu WANG Changfeng SUN Quan ZHANG Jun WEN 《Advances in Atmospheric Sciences》 SCIE CAS CSCD 2024年第4期701-716,共16页
Little is known about the mechanism of climate-vegetation coverage coupled changes in the Tibetan Plateau(TP)region,which is the most climatically sensitive and ecologically fragile region with the highest terrain in ... Little is known about the mechanism of climate-vegetation coverage coupled changes in the Tibetan Plateau(TP)region,which is the most climatically sensitive and ecologically fragile region with the highest terrain in the world.This study,using multisource datasets(including satellite data and meteorological observations and reanalysis data)revealed the mutual feedback mechanisms between changes in climate(temperature and precipitation)and vegetation coverage in recent decades in the Hengduan Mountains Area(HMA)of the southeastern TP and their influences on climate in the downstream region,the Sichuan Basin(SCB).There is mutual facilitation between rising air temperature and increasing vegetation coverage in the HMA,which is most significant during winter,and then during spring,but insignificant during summer and autumn.Rising temperature significantly enhances local vegetation coverage,and vegetation greening in turn heats the atmosphere via enhancing net heat flux from the surface to the atmosphere.The atmospheric heating anomaly over the HMA thickens the atmospheric column and increases upper air pressure.The high pressure anomaly disperses downstream via the westerly flow,expands across the SCB,and eventually increases the SCB temperature.This effect lasts from winter to the following spring,which may cause the maximum increasing trend of the SCB temperature and vegetation coverage in spring.These results are helpful for estimating future trends in climate and eco-environmental variations in the HMA and SCB under warming scenarios,as well as seasonal forecasting based on the connection between the HMA eco-environment and SCB climate. 展开更多
关键词 Hengduan Mountains Area normalized difference vegetation index climate change net heat flux downstream effects
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Influence of upstream solar wind on magnetic field distribution in the Martian nightside ionosphere
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作者 JiaWei Gao ZhaoJin Rong +3 位作者 Qi Zhang Anna Mittelholz Chi Zhang Yong Wei 《Earth and Planetary Physics》 EI CAS CSCD 2024年第5期728-741,共14页
Using over eight years of Mars Atmosphere and Volatile Evolutio N(MAVEN)data,from November 2014 to May 2023,we have investigated the Martian nightside ionospheric magnetic field distribution under the influence of ups... Using over eight years of Mars Atmosphere and Volatile Evolutio N(MAVEN)data,from November 2014 to May 2023,we have investigated the Martian nightside ionospheric magnetic field distribution under the influence of upstream solar wind drivers,including the interplanetary magnetic field intensity(∣BIMF∣),solar wind dynamic pressure(PS W),solar extreme ultraviolet flux(EUV),and Martian seasons(L s).Our analysis reveals pronounced correlations between magnetic field residuals and both∣BIMF∣and PS W.Correlations observed with EUV flux and Ls were weaker—notably,magnetic field residuals increased during periods of high EUV flux and at Mars perihelion.We find that the IMF penetrates to an altitude of 200 km under a wide range of upstream conditions,penetrating notably deeper under high∣BIMF∣andPSWconditions.Our analysis also indicates that EUV flux and IMF cone angle have minimal impact on IMF penetration depth.Those findings provide useful constraints on the dynamic nature of Martian atmospheric escape processes and their evolution,suggesting that historical solar wind conditions may have facilitated deeper IMF penetration and higher rates of ionospheric escape than are observed now.Moreover,by establishing criteria for magnetic‘quiet’conditions,this study offers new insights into the planet’s magnetic environment under varying solar wind influences,knowledge that should help refine models of the Martian crustal magnetic field. 展开更多
关键词 Martian magnetic field external magnetic field upstream solar wind drivers IMF penetration altitude magnetic field activity indices
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Bioengineering Downstream Technology Online Open Course Drives SPOC Hybrid Teaching Reform Based on Ideological and Political Education
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作者 Jiedan Liao 《Journal of Contemporary Educational Research》 2024年第9期17-24,共8页
In the context of emerging engineering disciplines,a hybrid teaching reform for the Bioengineering Downstream Technology course,based on ideological and political education and online open courses,is being carried out... In the context of emerging engineering disciplines,a hybrid teaching reform for the Bioengineering Downstream Technology course,based on ideological and political education and online open courses,is being carried out.This reform focuses on aspects such as“building a professional teacher team for ideological and political education,scientifically designing the ideological and political teaching system,innovating classroom teaching methods,and improving both formative and summative evaluation systems.”The“Craftsmanship in Education and Cultivating Soul and Roots”small private online course hybrid teaching reform for the Bioengineering Downstream Technology online open course provides a replicable model for the comprehensive implementation of ideological and political education in engineering courses and offers a reference for advancing ideological and political education and hybrid teaching reform in new engineering disciplines. 展开更多
关键词 Bioengineering downstream Technology Ideological and political Online open course Hybrid teaching
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Upstream-downstream cooperation approach in Guanting Reservoir watershed
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作者 YANGZhi-feng ZHANGWen-guo 《Journal of Environmental Sciences》 SCIE EI CAS CSCD 2005年第4期676-680,共5页
A case study is introduced and discussed concerning water dispute of misuse and pollution between up\| and down\|stream parts. The relations between water usage and local industrial structures are analyzed. Results sh... A case study is introduced and discussed concerning water dispute of misuse and pollution between up\| and down\|stream parts. The relations between water usage and local industrial structures are analyzed. Results show it is important to change industrial structures of the target region along with controlling water pollution by technical and engineering methods. Three manners of upstream-downstream cooperation are presented and discussed based on the actual conditions of Guangting Reservoir watershed. Two typical scenarios are supposed and studied along with the local plan on water resources development. The best solution for this cooperation presents a good way to help the upstream developing in a new pattern of eco-economy. 展开更多
关键词 WATERSHED COOPERATION upstream-downstream industrial structures Guanting Reservoir
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Upstream-Downstream Relationships in Terms of Annual Streamflow Discharges and Drought Events in Nebraska
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作者 Hong WU Leen Kiat SOH +3 位作者 Ashok SAMAL Tao HONG David MARX Xunhong CHEN 《Journal of Water Resource and Protection》 2009年第5期299-315,共17页
Upstream-downstream relationships of annual streamflow discharges and severity and frequency of stream-flow drought events are critical in understanding how streamflow droughts propagate over time and space. Such info... Upstream-downstream relationships of annual streamflow discharges and severity and frequency of stream-flow drought events are critical in understanding how streamflow droughts propagate over time and space. Such information can be used to resolve water disputes, trigger mitigation strategies, and understand how streamflow changes due to changes in the environment. During drought years, such information is even more critical as water resources are contested. The objective of this research is to study the upstream-downstream relationships of streamflow in Nebraska along four major river systems with diverse hydrologic characteris-tics and human activities: North Platte, Big Blue, Republican, and Niobrara. The relationships among the upstream and downstream stations along the four rivers are investigated by comparing several statistics de-rived from the annual flow discharge and on drought events. Trend analysis and coefficient of variation are applied to annual flow discharge values, and a host of drought-related parameters (e.g., annual maximum drought duration, annual accumulated drought duration, number of drought events) are also computed with respect to five different levels of streamflow drought events: water shortage, mild drought, moderate drought, significant drought, and extreme drought. The paired-t test and ANOVA with MIXED procedure are subse-quently applied to the statistics to observe whether there is a significant difference between upstream and downstream stations along a river. The analysis allows us to characterize the upstream-downstream relation-ships of the four river systems, laying the groundwork for further investigations to identify the reasons for some of the trends and observations. These findings will be essential in water resources management during or prior to hydrological droughts. 展开更多
关键词 Streamflow DROUGHT upstream-downstream Relationship Paired T-TEST Repeated Measures ANOVA with MIXED Procedure NEBRASKA
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Comparative Assessment of the Upstream and Downstream Water Qualities of River Tano in Ghana
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作者 Jackson Adiyiah Helena Aboagye-Larbi Mike Agbesi Acheampong 《Journal of Environmental Science and Engineering(A)》 2013年第5期283-292,共10页
River Tano, located in the Brong Ahafo region of Ghana, has a number of socio-ecological functions. Anthropogenic activities such as farming, washing, and discharge of industrial effluents into the river pose serious ... River Tano, located in the Brong Ahafo region of Ghana, has a number of socio-ecological functions. Anthropogenic activities such as farming, washing, and discharge of industrial effluents into the river pose serious threat to human health. In view of this, water quality campaign was carried out for a period of 12 months by taking samples from the source and the downstream end of the river and analysing for some physico-chemical parameters. The results showed that most of the physico-chemical parameters such as pH, fluoride, nitrite, manganese and temperature were not within the regulatory safe limit. Although the levels of total alkalinity, total iron, ammonia and phosphate kept fluctuating along the course of the river, the difference were not statistically significant apart from fluoride and phosphate which showed significant difference between the upstream and downstream levels. This may be attributed to anthropogenic activities such as farming and washing in the river which implies that human activities have impacted slightly on the water quality. It is recommended that the relevant stakeholders should come together to enforce the environmental laws regarding protection of water bodies and do continuous monitoring for early detection of any change in quality of the River Tano. 展开更多
关键词 PHYSICO-CHEMICAL water resources water quality River Tano upstream downstream.
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Multimodal Fuzzy Downstream Petroleum Supply Chain:A Novel Pentagonal Fuzzy Optimization 被引量:1
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作者 Gul Freen Sajida Kousar +2 位作者 Nasreen Kausar Dragan Pamucar Georgia Irina Oros 《Computers, Materials & Continua》 SCIE EI 2023年第3期4861-4879,共19页
The petroleum industry has a complex,inflexible and challenging supply chain(SC)that impacts both the national economy as well as people’s daily lives with a range of services,including transportation,heating,electri... The petroleum industry has a complex,inflexible and challenging supply chain(SC)that impacts both the national economy as well as people’s daily lives with a range of services,including transportation,heating,electricity,lubricants,as well as chemicals and petrochemicals.In the petroleum industry,supply chain management presents several challenges,especially in the logistics sector,that are not found in other industries.In addition,logistical challenges contribute significantly to the cost of oil.Uncertainty regarding customer demand and supply significantly affects SC networks.Hence,SC flexibility can be maintained by addressing uncertainty.On the other hand,in the real world,decision-making challenges are often ambiguous or vague.In some cases,measurements are incorrect owing to measurement errors,instrument faults,etc.,which lead to a pentagonal fuzzy number(PFN)which is the extension of a fuzzy number.Therefore,it is necessary to develop quantitative models to optimize logistics operations and supply chain networks.This study proposed a linear programming model under an uncertain environment.The model minimizes the cost along the refineries,depots,multimode transport and demand nodes.Further developed pentagonal fuzzy optimization,an alternative approach is developed to solve the downstream supply chain using themixed-integer linear programming(MILP)model to obtain a feasible solution to the fuzzy transportation cost problem.In this model,the coefficient of the transportation costs and parameters is assumed to be a pentagonal fuzzy number.Furthermore,defuzzification is performed using an accuracy function.To validate the model and technique and feasibility solution,an illustrative example of the oil and gas SC is considered,providing improved results compared with existing techniques and demonstrating its ability to benefit petroleum companies is the objective of this study. 展开更多
关键词 downstream petroleum supply chain fuzzy optimization multimodal optimization pentagonal fuzzy number
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高梯度磁选中非磁性颗粒的机械夹杂行为 被引量:1
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作者 张波 杜力 +2 位作者 李双佳 王一凡 郑霞裕 《有色金属工程》 CAS 北大核心 2024年第1期74-82,共9页
非磁性矿物颗粒的机械夹杂是影响高梯度磁选选择性的重要因素。基于自主设计的高梯度磁选试验装置,对磁介质上、下游累积物进行冷冻、剥离和独立分析,系统研究了各种关键参数对非磁性颗粒机械夹杂行为的影响。结果表明,磁介质下游捕集... 非磁性矿物颗粒的机械夹杂是影响高梯度磁选选择性的重要因素。基于自主设计的高梯度磁选试验装置,对磁介质上、下游累积物进行冷冻、剥离和独立分析,系统研究了各种关键参数对非磁性颗粒机械夹杂行为的影响。结果表明,磁介质下游捕集的选择性都优于上游。非磁性矿物的机械夹杂主要发生在介质上游,增加给矿流速和减小非磁性颗粒的粒度可以提高高梯度磁选的选择性,磁场强度对介质上下游机械夹杂的影响较小。在较低流速条件下,弱化上游捕集和强化下游捕集具有重要意义,并提出了提高选择性的两种潜在技术方案。 展开更多
关键词 高梯度磁选 机械夹杂 上下游累积 选择性
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数字化转型的溢出效应:扩散还是虹吸?——基于行业内领军企业与行业间产业链双重视角 被引量:2
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作者 刘玉斌 能龙阁 《经济与管理研究》 CSSCI 北大核心 2024年第6期38-57,共20页
本文基于创新扩散理论与外部性理论,利用2011—2021年中国上市企业和投入产出表数据,探讨行业内领军企业及行业间产业链上下游企业数字化转型对焦点企业转型的影响。研究结果显示:行业领军企业和产业链上下游企业数字化促进焦点企业转型... 本文基于创新扩散理论与外部性理论,利用2011—2021年中国上市企业和投入产出表数据,探讨行业内领军企业及行业间产业链上下游企业数字化转型对焦点企业转型的影响。研究结果显示:行业领军企业和产业链上下游企业数字化促进焦点企业转型,且产业链上游促进作用高于下游。一方面,数字化转型存在扩散效应,表现在领军企业与产业链上下游企业通过管理层决策同群效应和知识溢出效应促进焦点企业数字化转型;另一方面,数字化转型也存在虹吸效应,表现在产业链下游企业对焦点企业产生研发人才的虹吸效应,领军企业对焦点企业产生数字资本的虹吸效应。本文的研究对于提高领军企业引领带动作用、提升产业链协同效率具有重要启示,并为建设现代化产业体系提供新思路。 展开更多
关键词 领军企业 产业链上下游 数字化转型 扩散效应 虹吸效应
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长江下游干流沉积物重金属特征及生态风险评价 被引量:4
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作者 金阳 姜月华 +10 位作者 周权平 王晓龙 张鸿 梅世嘉 陈孜 杨海 吕劲松 侯莉莉 齐秋菊 贾正阳 杨辉 《中国地质》 CAS CSCD 北大核心 2024年第1期276-289,共14页
【研究目的】长江下游干流沿岸分布众多取水口,为保障用水安全和生态环境健康,亟需了解近岸沉积物中重金属相关现状。【研究方法】调查过程中自上而下分左右岸共采集沉积物样品85组,利用描述统计分析重金属含量特征,综合相关性分析和主... 【研究目的】长江下游干流沿岸分布众多取水口,为保障用水安全和生态环境健康,亟需了解近岸沉积物中重金属相关现状。【研究方法】调查过程中自上而下分左右岸共采集沉积物样品85组,利用描述统计分析重金属含量特征,综合相关性分析和主成分分析探讨重金属来源,采用地累积指数法、污染负荷法分析重金属污染程度,并评估其潜在生态风险。【研究结果】平均含量由高至低为Zn>Cr>Cu>Ni>Pb>As>Cd;上游至下游,Cu、Zn、Cr、Ni呈小幅波动增加趋势,As、Pb呈小幅波动下降趋势,Cd呈较大波动下降趋势;Cd的污染程度最重,主要来源于农业生产等人类活动,1~4级污染分别占比1.18%、1.18%、18.82%和34.12%,Cr和Ni为无污染,主要是工业生产源和地球化学自然源;中等污染程度(1≤PLI_(point)<2)的样点占比34.18%,潜在生态风险指数(RI)为19.48~388.62,轻微潜在生态风险、中等潜在生态风险、强潜在生态风险和极强潜在生态风险占比分别为38.82%、42.35%、17.65%和1.18%。【结论】长江下游干流沉积物中重金属含量较低,流域整体处于轻微—中等风险的无污染状态(PLI_(area)<1),右岸重金属平均含量、污染程度和潜在生态风险均普遍高于左岸。 展开更多
关键词 重金属 来源 污染程度 生态风险 水文地质调查工程 长江下游
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Study the Effectiveness of ISO 27001 to Mitigate the Cyber Security Threats in the Egyptian Downstream Oil and Gas Industry
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作者 Mohamed Shohoud 《Journal of Information Security》 2023年第2期152-180,共29页
As Egyptian oil and gas downstream information technology has grown digitally over the past decade, security breaches against these digitally connected systems have also increased. These cyber security threats could h... As Egyptian oil and gas downstream information technology has grown digitally over the past decade, security breaches against these digitally connected systems have also increased. These cyber security threats could have devastating effects on the operations and reputation of these companies. Preventing such cyberattacks is crucial. Especially, with the significance of the Egyptian oil and gas downstream sector to the local economy and the fact that many of these connected systems are sometimes managed remotely. This paper examines the value of the ISO 27001 standard in mitigating the effect of cyber threat and seeks to inspire decision-makers to the importance of the proactive measures to strengthen their organization’s cybersecurity posture and protect information critical assets. The study stresses the importance of improving the local educational system to bridge the gap between supply and demand for cybersecurity specialists by implementing a structured approach that emphasizes behavior modification to get a high return on investment in cybersecurity awareness. 展开更多
关键词 downstream Cyberattack Cyber Security Mitigate Decision-Makers Proac-tive Measure Critical Assets Behavior Modification
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煤层气产量预测分析决策支持系统在上下游一体化项目生产管理中的应用
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作者 李彦忱 刘杰 王箴 《石油科技论坛》 2024年第3期104-111,共8页
通过海量生产数据开展煤层气产量预测是上下游一体化大型项目管理中面临的挑战之一,针对该难题,中国石化集团国际石油勘探开发有限公司海外技术团队研发了煤层气产量预测分析决策支持系统。该系统以SQL、Spotfire、OFM及Enersight等主... 通过海量生产数据开展煤层气产量预测是上下游一体化大型项目管理中面临的挑战之一,针对该难题,中国石化集团国际石油勘探开发有限公司海外技术团队研发了煤层气产量预测分析决策支持系统。该系统以SQL、Spotfire、OFM及Enersight等主要应用软件为底层平台,通过二次开发及整合,搭建了数据整合、数据分析、预测转化及成果应用4个主要模块,以煤层气产量预测复杂性及经常出现的问题为切入点,开展煤层气产量预测综合分析、类比分析及递减分析,实现对产量预测的高效管理。该系统具有方便快捷、固定流程、分工明确、团队协作的特点。通过应用实例,展示了该系统针对海量生产数据,自上而下、由面到点、聚焦关键领域,高效筛查出产量预测的关键问题,并提出可行的修正方案,有效提升了煤层气产量预测精准度,为项目投资决策提供有力支持和保障。 展开更多
关键词 煤层气 产量预测 递减分析 上下游一体化 决策支持
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外资进入促进了企业全球价值链嵌入吗?——基于中国微观企业的经验证据
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作者 郑丹青 《北京理工大学学报(社会科学版)》 CSSCI 北大核心 2024年第2期193-206,共14页
外资进入是否改变了中国企业的全球价值链嵌入模式?利用中国工业企业数据库和海关贸易数据库在刻画企业全球价值链嵌入模式的动态演进基础上,探讨了外资进入对中国企业全球价值链嵌入模式的影响。研究表明:2000—2013年中国企业上游嵌... 外资进入是否改变了中国企业的全球价值链嵌入模式?利用中国工业企业数据库和海关贸易数据库在刻画企业全球价值链嵌入模式的动态演进基础上,探讨了外资进入对中国企业全球价值链嵌入模式的影响。研究表明:2000—2013年中国企业上游嵌入度不断提升但程度较小,下游嵌入度相对较大却持续下降,企业全球价值链分工地位整体为负但攀升态势明显;外资进入推动了企业上游环节的嵌入度,对下游环节嵌入度产生明显锁定效应,整体上外资进入的企业全球价值链地位效应表现出显著负向作用;一般贸易企业、外资企业、劳动密集型及低技术水平企业同行业外资进入的全球价值链地位负向效应明显;进一步的动态效应和影响机制分析发现,外资进入对企业全球价值链地位表现出显著动态抑制作用,会通过融资约束效应对企业全球价值链地位产生显著的正向调节效应,从而有利于缓解外资进入的全球价值链“低端锁定”风险。 展开更多
关键词 外资进入 企业全球价值链地位 上游嵌入度 下游嵌入度
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企业降碳减污协同推进的产业链联动效应
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作者 孙慧 夏学超 +1 位作者 祝树森 杨泽东 《中国人口·资源与环境》 CSSCI CSCD 北大核心 2024年第3期16-29,共14页
企业降碳减污协同推进不仅是提升环境质量的重要着力点,亦是在市场经济中提升竞争力的关键所在。产业链联动效应是探讨企业降碳减污协同推进的重要视角。基于约束效应、同群效应、规模效应3方面构建理论分析框架,使用2007—2021年沪深A... 企业降碳减污协同推进不仅是提升环境质量的重要着力点,亦是在市场经济中提升竞争力的关键所在。产业链联动效应是探讨企业降碳减污协同推进的重要视角。基于约束效应、同群效应、规模效应3方面构建理论分析框架,使用2007—2021年沪深A股上市公司样本数据,实证探析产业链上下游企业降碳减污协同推进联动效应的内在机理、联动类型和联动模式。实证结果表明:①产业链上下游企业降碳减污协同推进存在产业链联动效应,有助于焦点企业降碳减污的协同推进。②产业链依赖度越高、行业竞争程度越低、环境不确定性越高以及与上下游企业技术研发合作越紧密的焦点企业,其降碳减污协同推进受到产业链上下游企业降碳减污协同推进的联动效应越强。③界定焦点企业与上下游企业的联动类型发现,企业降碳减污协同推进同时受到上游供应商企业推动和下游客户企业拉动的影响,但是下游客户企业拉动效果更强。④界定焦点企业降碳减污协同推进的学习行为特征发现,焦点企业是通过主动学习来提升降碳减污协同推进能力,跨行业模仿学习对企业降碳减污协同推进提升作用更强。基于以上研究结论,为更好地促进企业微观个体实现降碳减污协同推进目标,强化产业链降碳减污协同推进的联动效应,政府应该制定产业链降碳减污协同推进联动专项规划,精准扶持存在联动困难的企业。企业要加强向具有降碳减污协同推进优势的标杆企业学习,助力碳达峰和碳中和目标提前实现。 展开更多
关键词 焦点企业 上下游企业 降碳减污协同推进 产业链联动效应
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企业研发经费的就业效应——基于制造业资本品上下游行业的空间计量分析
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作者 杜剑 于鑫 《中央财经大学学报》 CSSCI 北大核心 2024年第10期102-114,共13页
加大企业研发经费(R&D经费)投入会对就业产生何种影响是非常值得关注的问题。本文首先建立了基于研发而形成的资本品上下游行业模型,从理论上分析企业R&D经费对就业的影响。然后,基于我国2012—2021年制造业行业数据,运用空间... 加大企业研发经费(R&D经费)投入会对就业产生何种影响是非常值得关注的问题。本文首先建立了基于研发而形成的资本品上下游行业模型,从理论上分析企业R&D经费对就业的影响。然后,基于我国2012—2021年制造业行业数据,运用空间计量的方法对企业R&D经费的就业规模总效应和上下游行业就业结构变化进行实证检验。研究发现:我国企业R&D经费对就业规模总效应不显著;但资本品上游行业企业R&D经费增加会负向影响下游行业就业,使上游行业就业占比增加,发生就业结构上迁。异质性分析表明,设备型上游行业组的就业结构上迁效应明显。机制分析表明,上游行业产品创新增加促进了下游行业的资本品使用,对下游行业劳动力产生替代,促使就业结构向上迁移。研究结论对优化创新和就业政策、减缓摩擦性失业有一定现实意义和参考价值。 展开更多
关键词 企业R&D经费 就业结构迁移 资本品上下游 行业空间权重矩阵
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Dissolved Organic Matter Features of Three Adjacent Eastern Mediterranean Urbanized Watersheds
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作者 Nour Abboud Elias Michel Maatouk +1 位作者 Zeinab Matar Veronique Kazpard 《Open Journal of Modern Hydrology》 CAS 2024年第3期153-173,共21页
Landscape urbanization broadly affects ecosystems in coastal watersheds, but, until now, the influence of nonpoint source urban inputs on dissolved organic matter (DOM) amount, composition, and source is poorly unders... Landscape urbanization broadly affects ecosystems in coastal watersheds, but, until now, the influence of nonpoint source urban inputs on dissolved organic matter (DOM) amount, composition, and source is poorly understood. To understand how DOM composition varied with urbanization, fluorescence excitation-emission matrices (EEMs) were determined for urban and non-urban waters from upstream to downstream sites along three adjacent coastal watersheds that flow into the Mediterranean Sea. Two humic DOM fluorescent components (humic-like and fulvic-like peaks) and two proteinic components (tyrosine-like and tryptophane-like peaks) were identified by EEM fluorescence. The results indicated that urbanization had an important influence on DOM concentration and composition, with urban waters having a high degree of DOM variation due to different land uses surrounding each body of water. Urban waters show a higher DOM fluorescence index (FI), the highest fluorescence intensity of protein-like manifested also by BIX values, and a lower value of the humification index (HIX) than non-urban waters which were dominated by allochthonous inputs. In addition, the EEM was compared in dry and wet season where higher DOM amounts and FI appeared in summer due to autochthonous production coming from algae growth compared to allochthonous input from rainfall dominated in wet season. The concentration of DOC increased from upstream to downstream for the three rivers, especially Beirut River. The increase in DOC values was observed in both dry and wet seasons by 39 and 19 times respectively compared to upstream (0.93 - 0.91 mgC/L). 展开更多
关键词 Dissolved Organic Matter DOM EEM Fluorescence Spectroscopy Autochthonous/Allochthonous DOM Urbanization upstream/downstream Wet/Dry Season
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关于加强水库大坝下游水位监测的认识与建议 被引量:1
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作者 江超 吴全荣 +1 位作者 曹昕 闵国琪 《中国水利》 2024年第2期56-60,共5页
下游水位监测是1级~5级水库大坝必设的安全监测项目,但在实际建设过程中常常被忽视或误解,不利于充分发挥监测系统作用。通过设置下游水位监测,可以确定准确完整的坝体浸润线位置,支撑智慧水利建设;定量分析监测断面的防渗效果与渗流安... 下游水位监测是1级~5级水库大坝必设的安全监测项目,但在实际建设过程中常常被忽视或误解,不利于充分发挥监测系统作用。通过设置下游水位监测,可以确定准确完整的坝体浸润线位置,支撑智慧水利建设;定量分析监测断面的防渗效果与渗流安全性态,提高渗流安全监测资料分析深度;为大坝渗流计算提供可靠的重要边界条件参数,提升渗流计算成果可靠性与准确性。下游水位监测对大坝安全监测以及大坝安全管理至关重要,建议有条件的水库补充设置下游水位监测,进一步完善大坝安全监测系统。 展开更多
关键词 水库 大坝 安全监测 下游水位
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数字化转型、创新发展与制造业价值链高质量发展 被引量:7
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作者 齐平 宋威辉 《广东财经大学学报》 CSSCI 北大核心 2024年第1期4-18,共15页
创新驱动发展战略背景下,企业数字化转型对制造业价值链高质量发展具有重要意义。采用2007—2021年沪深A股制造业上市企业数据,从价值链上游度即“强链”和价值链长度即“延链”双重视角,探析企业数字化转型对制造业价值链高质量发展的... 创新驱动发展战略背景下,企业数字化转型对制造业价值链高质量发展具有重要意义。采用2007—2021年沪深A股制造业上市企业数据,从价值链上游度即“强链”和价值链长度即“延链”双重视角,探析企业数字化转型对制造业价值链高质量发展的影响效果、作用机制与异质性特征。研究结果表明:企业数字化转型从“强链”和“延链”两方面推动了制造业价值链高质量发展,且该结论通过了稳健性检验。作用机制检验表明,企业创新发展在此过程中具有显著的正向传导作用。异质性分析表明,在非国有制企业、技术密集型行业、劳动密集型行业和创新引领型城市,企业数字化转型通过“强链”和“延链”推动制造业价值链高质量发展的效果更为显著。为此,在城市层面应健全数字化转型治理体系,在行业层面应加快“新基建”建设进程,促进数字化均衡发展,在企业层面应鼓励以强带弱、协同发展,为企业数字化转型提速增质。 展开更多
关键词 数字化转型 制造业价值链 高质量发展 创新发展 价值链上游度(“强链”) 价值链长度(“延链”)
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以确保“一泓清水永续北上” 引领南水北调中线水源区水土保持高质量发展 被引量:2
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作者 胡甲均 《水利发展研究》 2024年第2期33-38,共6页
丹江口库区及上游是南水北调中线水源区(以下简称“水源区”),其水土保持高质量发展是保障“一泓清水永续北上”的重要支撑。文章针对水源区水土流失现状和特点,总结了丹江口库区及上游水土保持重点防治工程(以下简称“丹治”工程)实施... 丹江口库区及上游是南水北调中线水源区(以下简称“水源区”),其水土保持高质量发展是保障“一泓清水永续北上”的重要支撑。文章针对水源区水土流失现状和特点,总结了丹江口库区及上游水土保持重点防治工程(以下简称“丹治”工程)实施以来的水土保持成效,分析了水土保持面临的新形势和新要求,梳理了水土保持存在的短板和不足,研究提出了引领丹江口库区及上游水土保持高质量发展的对策举措,为各级政府加强南水北调中线水源区水土保持治理管理提供参考。 展开更多
关键词 丹江口库区及上游 水土保持 高质量发展 清水北上
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