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Study of Chemical and Biological Indicators of Saline Pollution of the Coastal Lake Sidi Boughaba(Kenitra,Morocco)
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作者 Manal Maaroufi Elmoctar Habiby +7 位作者 Fatima Aalama Salah Ait-Si Dounia Bassir Hajar Echayeb Mariam Aznag Brahim Bourkhis Khadija El Kharrim Driss Belghyti 《Journal of Environmental & Earth Sciences》 2025年第5期140-157,共18页
For around fifty years,the regression and degradation of wetlands were considered so worrying that they were the subject of an international Convention signed on 2 February 1971,in Iran(RAMSAR).This treaty aims to con... For around fifty years,the regression and degradation of wetlands were considered so worrying that they were the subject of an international Convention signed on 2 February 1971,in Iran(RAMSAR).This treaty aims to conserve wetlands meeting criteria of international importance through the notion of rational use of these spaces and their biodiversity.The national and even international value of Lake Sidi Boughaba(Kenitra,Morocco)lies in its biodiversity which allowed its inclusion on the Ramsar list in 1980.This importance motivated us to begin an ecological assessment of the level of its pollution through spatiotemporal monitoring and analysis of physicochemical tracers from surface waters at seven sampling stations between January and December 2023.The waters of Lake Sidi Boughaba are relatively basic(pH=8.63),cold(15.14℃),very hard(64 meq/L),quite turbid(7.65 NTU),very salty(1935.85μs/cm)and well saturated with Calcium ions=312;Magnesium=605;Chlorides=5892;Sulfates=944;Silicates=26(mg/l).Other elements including nitrates(1.29 mg/l),ammonium(1.56 mg/l),fluorides(410μg/l),iron(350μg/l)and manganese(35μg/l)are low.This study concludes that Lake Sidi Boughaba is classified in the category of oligomesotrophic lakes and that it is too threatened by the progressive transformation of its fresh water into brackish water and consequently the change in its benthic and planktonic fauna necessary for food of avian fauna.The study further concludes that this wetland is under significant threat,and to protect its biodiversity,innovative approaches to hydrological development are necessary. 展开更多
关键词 ECOSYSTEM LAKE POLLUTION Physicochemistry BIODIVERSITY sidi Boughaba Mehdia Morocco
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通用发动机SIDI缸内直喷技术解析 被引量:1
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作者 郑诚 《汽车维修》 2014年第11期6-7,共2页
缸内直喷就是将燃油喷嘴安装于气缸内,直接将燃油喷入气缸内与进气混合。喷射压的进一步提高,使燃油雾化更加细致,真正实现了精准地按比例控制喷油并与进气混合。通用燃油直喷技术的代号为SIDI,是Spark Ignition Direct Injection的缩... 缸内直喷就是将燃油喷嘴安装于气缸内,直接将燃油喷入气缸内与进气混合。喷射压的进一步提高,使燃油雾化更加细致,真正实现了精准地按比例控制喷油并与进气混合。通用燃油直喷技术的代号为SIDI,是Spark Ignition Direct Injection的缩写。一、SIDI燃油系统的组成如图1、图2所示,SIDI燃油系统由低压燃油系统和高压燃油系统2部分组成。 展开更多
关键词 缸内直喷 sidi 燃油系统 技术解析 燃油雾化 比例控制 高压油管 燃油泵 Injection 进气
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Synopsis of Fire's Forest in the Province of Sidi Bel Abbes: Analysis and Cartography 被引量:1
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作者 Nadia Bouguenaya Mohamed Benyahia Mohamed Ali Bouzidi 《Journal of Agricultural Science and Technology(B)》 2013年第10期745-750,共6页
In order to characterize the forest fires in the province of Sidi Bel Abbes (North West of Algeria) and depending on a statistical data analysis of a 17-year period (1996-2012), our works are oriented toward a stu... In order to characterize the forest fires in the province of Sidi Bel Abbes (North West of Algeria) and depending on a statistical data analysis of a 17-year period (1996-2012), our works are oriented toward a study of the area covered by forest fires in the 53 constituent municipalities of the region. To do this, we depended on the archives of the forest fires balance sheets in forest conservation in the wilaya of Sidi Bel Abbes. The results show that the region lost an annual average 29,929 ha of its total forest area for a maximum of 11,817.5 ha recorded in 2012. On the other hand, the use of the fire severity index "FSI" by town and its cartography in which we used the map of administrative division of the study area as support, has divided the region into six classes according to the risk of fire, where the municipalities belonging to the forest of Telagh whose land is rugged represent the risk of fire is greater. Indeed, this situation category the study area among the most exposed wilaya and the most affected by this problem at the national level and require new approaches to forest management for its conservation. These are paramount in reducing the risk of fires based on appropriate management plans to be established for each forest conservation area. 展开更多
关键词 sidi Bel Abbes forest fire FSI durable management cartography.
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Chemical and Organic Contamination of Phreatic Aquifer of Sidi Bouzid (Center West of Tunisia) 被引量:1
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作者 S. Chaibi N. Khlif +1 位作者 M. Chalbaoui W. Aydi 《Journal of Environmental Science and Engineering》 2010年第5期6-13,共8页
An understanding of the long-term changes in the nitrate and microbial contamination pattern of the groundwater of Sidi Bouzid (Centre West of Tunisia) is critical to conservation of drinking water in rural areas su... An understanding of the long-term changes in the nitrate and microbial contamination pattern of the groundwater of Sidi Bouzid (Centre West of Tunisia) is critical to conservation of drinking water in rural areas supporting mixed land-use activities such as cropping, livestock farming, and residence. The phreatic aquifer was revealed polluted by domestic disposals of the wastewaters in the urban zone. The average nitrate concentration in the groundwater of the east of the mioplioquaternary aquifer of Saddaguia (Sidi Bouzid) rose from 50 mg NO3- during 1996 to over 100 mg in 2003, which represents an increase of some 10 mg per year. Nitrate groundwater pollution during the period 1996-2003 was the result of the abusive use of fertilizers.In the cultivated zone, we must reduce the effects of the excessive use of the nitrogen fertilizers on the basis of monitoring soil once a year, managing water resources, rationalizing the use of the chemical substances. In urban zones, most of lost wells located in the perimeter reveal the gravity of the state of the aquifer. This last is organically polluted and requires an immediate action for the generalization of the purification network. We need to take into account the reality of under soil in all future planning's and arrangements. A scheme of sanitation seems necessary before all plans of arrangement. The extension of the sewer network must give the priority to the most vulnerable zones. 展开更多
关键词 AQUIFER WASTEWATER chemical substances microbial contamination sidi Bouzid (Tunisia).
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阿尔及利亚SIDI BEL ABBES供水工程水力计算探讨
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作者 何小英 刘志荣 《有色冶金设计与研究》 2002年第U10期32-35,共4页
目前国内外广泛使用的水力计算理论及公式不尽相同,通过长距离输水的工程实例,对国内外的计算方法进行比较分析,对合理选择公式及参数提出建议。
关键词 阿尔及利亚sidi BEL ABBES供水工程 水力计算 计算参数 沿程水头损失 局部水头损失
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Ethnobotanical Study of Medicinal Plants Used in the Province of Sidi Slimane (Morocco)
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作者 A. Zaher M. Boufellous +4 位作者 H. Jaber H. El Hartiti M. Barrahi M. Ouhssine B. Bourkhiss 《Journal of Biosciences and Medicines》 2018年第9期25-35,共11页
An ethnobotanical study of medicinal plants carried out in the province of Sidi Slimane (Rabat-Salé-Kénitra Region). It has been added to the catalog of medicinal plants and to classify all the information c... An ethnobotanical study of medicinal plants carried out in the province of Sidi Slimane (Rabat-Salé-Kénitra Region). It has been added to the catalog of medicinal plants and to classify all the information concerning the therapeutic uses practiced by the local population. Using 300 questionnaire cards, ethnobotanical surveys were conducted over a period of two years (2015 and 2016). The survey allowed us to identify 46 species belonging to 43 genera and 24 botanical families. In addition, the leaves are the most used part as an infusion to treat diseases. In terms of diseases treated, digestive disorders rank first (31.59%), followed by respiratory diseases (24.30%) and diseases of the nervous system (17.01%). The results obtained will be a very valuable source of information for the region studied and for the scientific community. They could be a database for further research in the fields of phytochemistry and pharmacology and for the purpose of searching for new natural substances. 展开更多
关键词 Ethnobotanical STUDY PROVINCE of sidi Slimane MEDICINAL PLANTS FLORISTIC
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Physic-Chemical Evaluation of Urban Wastewater of the Town of Sidi Kacem
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作者 Omar El Rhaouat Imane El Kherrati +7 位作者 Fatiha El khayyat Hamid Chiguer Karima Ezziani Abdalsalam Ibeda Mostafa Fareh Youssef Saidi Khadija El Kharim Driss Belghyti 《Computational Water, Energy, and Environmental Engineering》 2014年第1期30-35,共6页
The goal of this study is the evaluation of pollution by the physic-chemical characterization of urban wastewaters discharged in the river R’dom of the town Sidi Kacem. The motivation of this study is multiple firstl... The goal of this study is the evaluation of pollution by the physic-chemical characterization of urban wastewaters discharged in the river R’dom of the town Sidi Kacem. The motivation of this study is multiple firstly to give an answer to the choice of methods of treatment of raw sewage and secondly to raise awareness of the pollution of the river R’dom who is a source of irrigation in the region. The physic-chemical analyses were carried out on the level of the collector 1 (domestic collector of the Zaouia District) and that of collector 2 (domestic collector of the allotments Thami Amar, road of Tangier and Saada), during the year 2012 at the same time “in situ” and at the Laboratory of Environment (Faculty of Sciences Kenitra). The polluting load out of organic matter (DBO5, DCO, MES), out of mineral matter (Cl-, Ca2+, Mg2+, K+, , Na+) and out of nitrogenized matter (, , Nitrogenize total) was more important, except for the temperature and of the pH which are in conformity with the Moroccan standards of rejection. Ratios DCO/DBO5, DBO5/DCO and MES/DBO5 inform about the biodegradability of these effluents and permitted choice of the suitable treatment process. Indeed, results obtained show that the domestic effluents exceed the national standards of rejection, which requires an intervention of the competent jurisdictions in order to preserve the public health, to protect the environment and install an efficient sewage treatment plant to ensure a sustainable development. 展开更多
关键词 WASTEWATERS Physic-Chemistry Pollution sidi Kacem Morocco
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Hydrological Modelling of Sidi Jabeur Watershed (Morocco) Using Spatially Distributed Model ATHYS
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作者 Mourad Khattati Mostapha Serroukh +3 位作者 Ismail Rafik Hakim Mesmoudi Brirhet Hassane Yassine Bouslihim 《Journal of Geoscience and Environment Protection》 2016年第1期77-83,共7页
The objective of this study is to model the hydrology in the Sidi Jabeur basin, located in Bouregreg watershed at the north-central of Morocco, using the spatially distributed model (ATHYS) in order to understand and ... The objective of this study is to model the hydrology in the Sidi Jabeur basin, located in Bouregreg watershed at the north-central of Morocco, using the spatially distributed model (ATHYS) in order to understand and determine the different watershed hydrological processes. The study requires the collection of a series of data as inputs models namely rainfall data, water quantity, soil occupation, digital terrain model and requires also a calibration in order to evaluate the model in validation phase. The simulation results are obtained from the validation phase aim to replicate the operation of Sidi Jabeur watershed, and present a suitable adjustment perspective of the observed hydrograph. These results show that the objective is achieved and a model distributed like ATHYS plays an effective role in improving the efficiency and presents a high advantage in anticipation of runoff volume. 展开更多
关键词 Distributed Model HYDROLOGY sidi Jabeur Watershed ATHYS
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Qualitative and Environmental Aspects Study of Water Distributed in West Algeria: The Case of Sidi Bel Abbes City
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作者 Habib Meliani Mohamed Benyahia Mohamed Ali Bouzidi 《Journal of Life Sciences》 2013年第9期1009-1018,共10页
Water comes from various different sources, such as lakes, rivers, streams, springs and boreholes. Depending on the quality of its source, water will almost certainly have to be treated to make it safe to drink. All w... Water comes from various different sources, such as lakes, rivers, streams, springs and boreholes. Depending on the quality of its source, water will almost certainly have to be treated to make it safe to drink. All water supplies for human consumption must be well stored, free from micro-organisms, parasites and any substances that endanger public health if found in sufficient numbers or concentrations, in the same time. In our continued effort for a better result in our study of qualitative aspects, by physicochemical and bacteriological analysis, the authors focus in two crucial questions: a) is the water quality of Sidi-bel-Abbes good or bad ,and well stored? b) is the people of Sidi-bel-Abbes are aware of the importance of water and knowledgeable about how to use this vital? This study is the first to use data from I real work based upon a developed method and a good investigation to know exactly if water of Sidi-Bel-Abbes is safely treated, well stored and consumed in resemble way. In first, the authors plotted the method in analysing the qualitative aspect of water using developed material for a precise result starting by the distribution connection (condition and management) and the verification of water tank storage and finishing by analyzing the all the aspect of water (physicochemical and bacteriological analysis). In second, the authors focus on the way that people of Sidi Bel Abbes used and consumption water by introducing a targeted method (questionnaires) which help us a lot to know precisely the way, time and the real quantity of water consumed daily. In final step of our study of qualitative aspects, by physico-chemical and bacteriological, and environmental analyses, investigation processed by PCA (principal component analysis) of the drinking water supplied to Sidi Bel Abbes city (Algeria north-west) concluded by an encouraging result, that despite the various constraints faced by the departments concerned, they ensure the supply of safe drinking water in households almost daily. 展开更多
关键词 Drinking water sidi Bel Abb6s city qualitative and environmental aspects PCA
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SIDIS地震解释系统软件功能配套与发展
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作者 王祁峰 《中国海上油气(地质)》 1991年第1期63-69,共7页
为了充分发挥SIDIS机在油田勘探开发中的作用,针对该机器软件功能的不足,编制了输入、输出接口程序,并发展了速度场处理、层速度反演、岩性参数转换、复地震技术等几方面的应用软件,文中介绍了所发展软件的数学原理、运算功能和应... 为了充分发挥SIDIS机在油田勘探开发中的作用,针对该机器软件功能的不足,编制了输入、输出接口程序,并发展了速度场处理、层速度反演、岩性参数转换、复地震技术等几方面的应用软件,文中介绍了所发展软件的数学原理、运算功能和应用效果。 展开更多
关键词 sidiS机 地震解释系统 软件配套 油田勘探开发 功能扩充 储层
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The Bacterial Load of Hospital Discharges(Sidi Kacem,Morocco)
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作者 Sanae Sadek F.Benel Harkati +7 位作者 K.Elkharrim F.Jeddi I.Rhiate Moufouad M.Elmarkhi A.Khadmaoui S.Mouden Z.Dakir D.Belghyti 《Advances in Microbiology》 2013年第7期511-514,共4页
Fecal microorganisms, which are indicators or pathogens, have an optimum growth in the specific conditions of the internal environment animal or human. Therefore, when issued by a host, they result in sudden and drast... Fecal microorganisms, which are indicators or pathogens, have an optimum growth in the specific conditions of the internal environment animal or human. Therefore, when issued by a host, they result in sudden and drastic changes in the environment. This study aims at bacteriological characterization of the effluent from the provincial hospital in Sidi Kacem. And it shows that the effluent from the hospital contributing to non-regulatory standards ultimately reaches the environment (river wadi floor, animal, vegetable...). The results of bacteriological analyses (Total Coliforms, Fecal Coliforms) about sewage from the provincial hospital depending on the day of rest and work in the city of Sidi Kacem are presented with means respectively 557 × 104 and 328 × 104 in the rest and working days 555 × 104, 342 × 104 and the much higher maximum working days from the day of rest are 64 × 105 and 42 × 105. The results obtained show that the rate of bacteria (CT-CF) exceeds standards recommended by CNS (1994) and WHO (1996, 1997). These results have adverse effects on human life, animal, environment and ecosystem in general. 展开更多
关键词 BACTERIOLOGY Total Coliforms Fecal Coliforms HOSPITAL sidi Kacem Morocco
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Survey of Parasitologique Surface Water Quality(R’Dom Oued Sidi Kacem,Morocco)
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作者 Fatima Benel Harkati Khadija Elkharrim +1 位作者 Sadek Sanae Driss Belghyti 《Journal of Environmental Protection》 2013年第11期1236-1239,共4页
Domestic effluent from the city of Sidi Kacem in the north-western Morocco is released untreated into the Oued R’dom. We propose in this study to proceed with sampling wastewater at the three collectors Oued R’dom f... Domestic effluent from the city of Sidi Kacem in the north-western Morocco is released untreated into the Oued R’dom. We propose in this study to proceed with sampling wastewater at the three collectors Oued R’dom from upstream (Bab tissra) to downstream (Zirara) through the domestic center of the city of Sidi Kacem. The sampling was carried out twice a month over a period of five months (January, February, March, April and May). We used the technique Bailenger amended by [1]. At the upstream percentages of positive samples helminth eggs found in wastewater are: Nematodes 30%, 20% and 10% Ascaris sp, Trichuris sp, Enterobius vermicularis for Cestodes 30% Taenia. Sp and the eggs and larvae of strongyles 30%. At the home collector (C) nematodes are represented by the eggs of Ascaris sp, 60%, followed by Tri-churis sp. 40% for Enterobius. Vermicularis eggs sp. représentent 20% of the class Cestoda with percentages of positive samples for Taenia sp 30% and 10% for Hymenolepis. sp. is isolated from cyst protozoan Entamoeba coli 10% for eggs, and larvae of strongyles 60% presented in the wastewater at the Downstream class nematodes is 70% with 40% of Ascaris sp, and 30% Trichuris sp. la class Cestoda is represented by 30% of Taenia. Sp. et Hymenolepis’s. Sp. 10%. For eggs and larvae of strongyles is 40%. Exceeding the WHO standards, these parasites pose a potential hazard to the direct and indirect use of wastewater from the town of Sidi Kacem. 展开更多
关键词 WASTEWATER Noise POLLUTION R’Dom Oued sidi Kacem Morocco
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凯迪拉克SIDI家族 完美演绎卓然驾控感受
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《新知客》 2010年第3期127-127,共1页
高效动力科技营造卓然驾控感受一直以来,凯迪拉克对于性能的追求从未妥协过。正是这样的信念,使其汇集全球顶尖科技与精湛技艺倾力打造了SIDI智能直喷发动机。作为凯迪拉克缸内直喷技术方面的核心成果,SIDI是凯迪拉克领先核心技术的新象... 高效动力科技营造卓然驾控感受一直以来,凯迪拉克对于性能的追求从未妥协过。正是这样的信念,使其汇集全球顶尖科技与精湛技艺倾力打造了SIDI智能直喷发动机。作为凯迪拉克缸内直喷技术方面的核心成果,SIDI是凯迪拉克领先核心技术的新象征,而"SIDI" 展开更多
关键词 sidi 缸内直喷技术 广州车展 直喷 实地测试 功率提升 技术术语 时尚动感 产品阵容 豪华车市场
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上海通用雪佛兰科鲁兹1.5 SIDI
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作者 陈征 崔凯 《汽车与运动》 2014年第11期44-45,共2页
测试地点:中国·沈阳·棋盘山尽管没有它的增压发动机版本那么运动性十足,但是配备1.5SIDI发动机的全新一代科鲁兹依然带给我们不少惊喜全新一代科鲁兹增压版本刚刚登上杂志,我们就收到了它另一个版本的试驾邀请,新的版本最大... 测试地点:中国·沈阳·棋盘山尽管没有它的增压发动机版本那么运动性十足,但是配备1.5SIDI发动机的全新一代科鲁兹依然带给我们不少惊喜全新一代科鲁兹增压版本刚刚登上杂志,我们就收到了它另一个版本的试驾邀请,新的版本最大的特征是使用了全新开发的1.5 SIDI直喷发动机,也是这项以往仅用在通用更高级别车型上的中置直喷技术,首次被运用在紧凑型中级车上。1.5 SIDI发动机采用喷油嘴顶置的设计,将进排气机构整合在缸体内的构造。 展开更多
关键词 sidi 增压发动机 棋盘山 测试地点 自然吸气 直喷 机构整合 经济油耗 综合油耗 燃油经济性
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直喷汽油机燃烧系统开发中的喷雾激光诊断技术 被引量:20
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作者 张玉银 张高明 许敏 《汽车安全与节能学报》 CAS 2011年第4期294-307,共14页
我国的直喷汽油发动机(SIDI)技术开发还不成熟。在SIDI燃烧系统的研发中,激光诊断、三维计算流体力学(3-DCFD)和基于光学发动机的燃烧诊断是三种重要技术。激光诊断技术可对燃油雾化与蒸发过程进行可视化以及定量测量,为数值计算和建模... 我国的直喷汽油发动机(SIDI)技术开发还不成熟。在SIDI燃烧系统的研发中,激光诊断、三维计算流体力学(3-DCFD)和基于光学发动机的燃烧诊断是三种重要技术。激光诊断技术可对燃油雾化与蒸发过程进行可视化以及定量测量,为数值计算和建模提供实验验证进而提高仿真的精确性,为缸内混合气形成过程及燃烧诊断提供直观的物理描述和解释。该文综述了SIDI喷雾的激光诊断技术,它涵盖了对喷雾结构、流场、粒径、燃油蒸发、混合气浓度场等的测量技术,为直喷燃烧系统中喷雾、气流运动和燃烧室形状三者的匹配与优化提供重要技术手段。 展开更多
关键词 直喷汽油机(sidi) 激光诊断 燃油喷雾 雾化和蒸发
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新能源汽车产业政府R&D补贴效果的实证研究 被引量:13
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作者 李兆友 齐晓东 刘妍 《东北大学学报(社会科学版)》 CSSCI 北大核心 2017年第4期356-363,370,共9页
采用2011—2015年中国新能源汽车产业上市公司面板数据,通过静态与动态面板数据模型分析了政府直接补贴、间接补贴对企业R&D投入的影响。研究结果表明:政府直接补贴对企业R&D投入的激励效应显著,而政府间接补贴对企业R&D投... 采用2011—2015年中国新能源汽车产业上市公司面板数据,通过静态与动态面板数据模型分析了政府直接补贴、间接补贴对企业R&D投入的影响。研究结果表明:政府直接补贴对企业R&D投入的激励效应显著,而政府间接补贴对企业R&D投入的影响存在一定的不确定性;同时,企业规模、知识存量显著促进了政府R&D补贴的作用效果,而企业技术水平对政府R&D补贴的影响效果不明显。在上述结论基础上,为提高政府R&D补贴有效性,应完善以下政府职能:加强官方信息的披露,提高补贴政策的稳定性与针对性,充分发挥政府直接补贴、间接补贴的作用,建立完善的补贴准入和退出机制。 展开更多
关键词 政府R&D补贴 企业R&D投入 补贴效果 动态面板数据模型
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收益分享契约对供应链性能的影响分析 被引量:10
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作者 蔡建湖 周根贵 《计算机集成制造系统》 EI CSCD 北大核心 2008年第8期1636-1645,共10页
为优化季节性商品两级供应链的性能,引入收益分享契约。供应商通过分享零售商的销售收入,可以有效地降低批发价,吸引零售商订购更多的商品,并且供应商通过调节批发价和收益分享因子可以在协调供应链的前提下任意划分供应链的总利润。讨... 为优化季节性商品两级供应链的性能,引入收益分享契约。供应商通过分享零售商的销售收入,可以有效地降低批发价,吸引零售商订购更多的商品,并且供应商通过调节批发价和收益分享因子可以在协调供应链的前提下任意划分供应链的总利润。讨论了收益分享契约在供应商管理库存模式下的应用,找到了优化供应链性能的决策集。进一步分析了批发价为0时供应链性能的优化策略,通过引入剩余补贴因子实现了在协调供应链的同时任意分配供应链的总利润。最后用数值算例对结论进行了说明。 展开更多
关键词 供应链 报童模型 收益分享契约 协调 批发价 剩余补贴因子
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典范对应分析在重金属污染区土壤性质及土壤酶活性关系中的应用——以阳朔县思的村为例 被引量:5
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作者 李强 靳振江 杨荣梅 《热带地理》 北大核心 2014年第1期14-19,共6页
运用典范对应分析(Canonical Correspondence Analysis,CCA)对广西阳朔思的村铅锌矿尾砂坝坍塌后的污染农田土壤酶活性、土壤性质进行研究。结果表明:pH值、全铅和全锌是影响土壤其他因子(碱解氮、有机碳、速效磷、阳离子交换量、蔗糖... 运用典范对应分析(Canonical Correspondence Analysis,CCA)对广西阳朔思的村铅锌矿尾砂坝坍塌后的污染农田土壤酶活性、土壤性质进行研究。结果表明:pH值、全铅和全锌是影响土壤其他因子(碱解氮、有机碳、速效磷、阳离子交换量、蔗糖酶、脲酶和碱性磷酸酶)的重要因素。该区污染土壤尽管经过当地农民长达逾40 a的耕种,但土壤有机质、阳离子交换量、速效磷和碱解氮质量分数仍处于较低的水平,彼此之间的相关系数与其在CCA排序图中的夹角变化规律一致。土壤碱性磷酸酶活性与全锌质量分数呈正相关,因而在CCA排序图中,土壤碱性磷酸酶活性与全锌质量分数的夹角较小。尽管铅-锌污染物与蔗糖酶和脲酶的相关性不显著,但铅-锌污染物的存在造成蔗糖酶和脲酶活性的降低,因而在CCA排序图中,土壤中的铅-锌污染物与蔗糖酶和脲酶基本处于相反的两端,从而弥补相关分析结果信息量不足的弊端。鉴于CCA排序图能够直观展示土壤酶对重金属污染物的敏感强度以及土壤有机碳与养分循环物质之间的相互关系,因此可作为探索土壤因子内在联系的重要工具。 展开更多
关键词 铅锌尾矿砂 土壤酶 土壤性质 典范对应分析 思的村
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节能减排技术研发的补贴和合作政策比较 被引量:5
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作者 曹国华 赖苹 朱勇 《科技管理研究》 CSSCI 北大核心 2013年第23期27-32,40,共7页
在外生的排放税的条件下,将补贴和合作两种技术激励政策分别应用在节能减排技术研发即生产工艺研发和污染减排研发上。通过建立政府和企业之间的互动博弈模型,分析比较两种政策下的研发水平、利润和社会福利。研究发现:(1)当生产工艺研... 在外生的排放税的条件下,将补贴和合作两种技术激励政策分别应用在节能减排技术研发即生产工艺研发和污染减排研发上。通过建立政府和企业之间的互动博弈模型,分析比较两种政策下的研发水平、利润和社会福利。研究发现:(1)当生产工艺研发溢出率较低时,补贴政策下的生产工艺研发水平高于合作政策下的生产工艺研发水平;当生产工艺研发溢出率较高时,刚好相反。(2)当排放税率小于临界税率,补贴政策下的污染减排研发水平高于合作政策下的污染减排研发水平;当排放税率大于临界税率,结论相反。研究结果为政府选择正确的技术激励政策、企业选择正确的研发行为提供有力的理论支撑。 展开更多
关键词 节能减排 生产工艺研发 污染减排研发 补贴 合作
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一种系统方法论—旋进原则 被引量:21
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作者 王浣尘 《系统工程》 CSCD 1994年第5期9-12,共4页
本文介绍难度自增殖系统及其相应的方法伦,即螺旋式结合推进原则,可简称为旋进原则(SPIPRO Principles),并对施进原则的含义及机理作了研究。举例说明旋进原则广泛应用的可能性。最后,从原本方法和派生方法的角度对旋进原则作了进一步... 本文介绍难度自增殖系统及其相应的方法伦,即螺旋式结合推进原则,可简称为旋进原则(SPIPRO Principles),并对施进原则的含义及机理作了研究。举例说明旋进原则广泛应用的可能性。最后,从原本方法和派生方法的角度对旋进原则作了进一步的分析研究。 展开更多
关键词 系统方法论 旋进原则 系统工程
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