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铝青铜铸件低压铸造工艺参数的计算机模拟及优化 被引量:1
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作者 王明娜 朱丽娟 董秀奇 《河北科技师范学院学报》 CAS 2021年第3期42-47,共6页
为确定铝青铜铸件低压铸造的最佳工艺参数,利用Procast软件模拟了砂型低压铸造铝青铜泵盖铸件的凝固过程及缩孔分布。通过对不同砂型、浇注速度、浇注温度条件下铸型充填、凝固过程的模拟以及对缩松缺陷预测的分析比较,优化出低压铸造... 为确定铝青铜铸件低压铸造的最佳工艺参数,利用Procast软件模拟了砂型低压铸造铝青铜泵盖铸件的凝固过程及缩孔分布。通过对不同砂型、浇注速度、浇注温度条件下铸型充填、凝固过程的模拟以及对缩松缺陷预测的分析比较,优化出低压铸造的合理工艺参数为:顺序凝固浇注速度、温度在不出现冷隔的前提下,越低越好,1150℃为最佳浇注温度;铸型的导热系数越小越不易出现集中缩孔缩松,硅砂型为最佳铸型;由快变慢的压力变化充型方式比匀速充型更能减少铸件的缩孔缩松,更有利于顺序凝固,按照P=6000t曲线加压铸件最佳。 展开更多
关键词 铝青铜 低压铸造 最佳工艺参数 计算机模拟
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公众水文学--技术体系
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作者 邱顺添 王明娜 王佳 《天津大学学报(自然科学与工程技术版)》 EI CAS CSCD 北大核心 2021年第11期1101-1110,共10页
公众水文学是一个通过获取多源与多元的泛在感知水文信息,汲取水文学新知识,并根据新知识重构水文认知和模型框架,解答水文学基本问题,满足社会发展对水文知识需求的新兴研究领域.公众水文学一方面通过全新的方式获取水文数据进而推动... 公众水文学是一个通过获取多源与多元的泛在感知水文信息,汲取水文学新知识,并根据新知识重构水文认知和模型框架,解答水文学基本问题,满足社会发展对水文知识需求的新兴研究领域.公众水文学一方面通过全新的方式获取水文数据进而推动水文学跨越式发展,另一方面可增加公众在水文研究过程中的成就感,促进水文学与社会的互馈.本文着重描述了公众水文学的技术体系,从数据、技术、理论、社会4个维度阐述了公众水文学的主要建设内容,介绍了公民科学、社会水文学、现代水文学与公众水文学的区别和共同点,论述了公众水文学在中国的发展机遇:完善的基础设施、不断发展的新基建、逐步公开和共享的信息、高密度的人口、坚实的经济基础以及较强的政府和地方组织能力,使公众水文学可发展为具有中国特色的水文学新领域.最后,提出了公众水文学面临的挑战,并从研究体系的构建、技术的发展、应用领域的扩展和水文学发展的推进讲述了该领域未来的发展趋势.公众水文学综合了公共体系、智能化技术和水文学理论,将水文和社会有机结合起来,发展成一个新的研究领域,可以打破数据的壁垒,协助水文学实现突破式发展;同时,可将水文科学反馈于社会,增加公众参与度和价值感,拉动水文学和社会的联动作用. 展开更多
关键词 公众水文学 水文学 感知技术 泛在数据 理论革新
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218名护理人员对血源性传染病防治知识知晓率及其影响因素分析 被引量:5
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作者 王明娜 陈韫琴 +1 位作者 刘小玲 秦璇 《医学动物防制》 2019年第5期482-484,487,共4页
目的了解护理人员对血源性传染病防治知识的知晓情况,探讨并分析其影响因素。方法对218名护理人员进行有关血源性传染病防治知识的问卷调查,对调查结果进行统计描述和分析。结果受访护理人员平均年龄(26. 43±6. 35)岁,大专占47. 71... 目的了解护理人员对血源性传染病防治知识的知晓情况,探讨并分析其影响因素。方法对218名护理人员进行有关血源性传染病防治知识的问卷调查,对调查结果进行统计描述和分析。结果受访护理人员平均年龄(26. 43±6. 35)岁,大专占47. 71%(104/218),5年以下护龄占42. 20%(92/218),护士占44. 95%(98/218); 85. 32%(186/218)接受过血源性传染病防护知识培训,30. 28%(66/218)表示不了解标准预防知识;标准化总分为46. 53~96. 17(78. 75±7. 49)分,处于较好的人数占调查总数的比重最高,占34. 86%(76/218),不及格所占比重最低,占5. 50%(12/218);多因素分析结果显示,是否接受过培训(OR=34. 39,95%CI=14. 968~79. 075)、职称(OR=0. 22,95%CI=0. 098~0. 558)和护龄(OR=0. 34,95%CI=0. 143~0. 709)是影响护理人员对血源性传染病防治知识知晓程度的影响因素。结论护理人员对血源性传染病的防护知识知晓情况处于一般水平,接受过培训、高职称和高护龄护理人员对防治知识的掌握程度相对较好。应加强专项培训,提高护理人员传染病防治知识和防护意识。 展开更多
关键词 护理人员 血源性传染病 防治知识 影响因素
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古尔班通古特沙漠灌木冠幅预测模型 被引量:3
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作者 王明娜 张定海 +1 位作者 张志山 路丽宁 《中国沙漠》 CSCD 北大核心 2022年第4期139-150,共12页
古尔班通古特沙漠是中国第二大沙漠,也是中国固定和半固定沙丘主要分布区,固沙灌木种较多。冠幅不仅是反映固沙灌木可视化的重要参数,也是反映沙漠植被生长情况的重要变量。以3种沙丘(固定沙丘、半固定沙丘和流动沙丘)上主要固沙灌木为... 古尔班通古特沙漠是中国第二大沙漠,也是中国固定和半固定沙丘主要分布区,固沙灌木种较多。冠幅不仅是反映固沙灌木可视化的重要参数,也是反映沙漠植被生长情况的重要变量。以3种沙丘(固定沙丘、半固定沙丘和流动沙丘)上主要固沙灌木为研究对象,利用12种基础模型、BP(Backpropagation Neural Network)神经网络和支持向量机(Support Vector Machine,SVM)机器学习算法建立了基于固沙灌木株高和冠长率的冠幅预测模型,同时将两种机器学习算法拟合结果与基础模型进行比较,最终选出了适合研究区的冠幅预测模型。结果表明:(1)不同沙丘类型和不同灌木种类的最优冠幅预测模型不同,且固定沙丘和半固定沙丘模型优于流动沙丘。3种沙丘类型最优拟合为M2(Quadratic Model)模型;(2)白梭梭(Haloxylon persicum)在半固定沙丘和流动沙丘上拟合的最优模型分别为M2、M7(Gompertz),沙拐枣(Calligonum mongolicum)最优模型为M2,蛇麻黄(Ephedra distachya)和油蒿(Artemisia ordosica)在半固定沙丘和流动沙丘上拟合较优模型分别为M2、M7。总体来说,基础模型M2和M7可以较好地预测不同类型的灌木冠幅值;(3)基于径向基(Radial Basis Function)核函数的支持向量回归机的冠幅预测模型明显优于BP神经网络模型。 展开更多
关键词 株高 冠幅 冠长率 基础模型 BP神经网络 SVM支持向量机
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Dualistic water cycle pattern and its evolution in Haihe River basin 被引量:18
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作者 LIU JiaHong QIN DaYong +2 位作者 wang Hao wang mingna YANG ZhiYong 《Chinese Science Bulletin》 SCIE EI CAS 2010年第16期1688-1697,共10页
The Haihe River basin is widely recognized as an area in China which is most severely affected by human activities.The water resources utilization and recycling in the basin is very complex, and the characteristic of ... The Haihe River basin is widely recognized as an area in China which is most severely affected by human activities.The water resources utilization and recycling in the basin is very complex, and the characteristic of the dualistic water cycle is becoming more and more prominent.The ever-growing demand of water for modern industry and domestic life nearly dries up all the natu-ral runoff.Meanwhile, industrial, agricultural and domestic wastewater discharges cause severe deterioration in water quality.Consequently, many of water courses are either dried out or being heavily polluted.Modern water resources management can no longer rely on the "monitoring-rehabilitation" model which was originally developed based on the natural water cycle.This paper analyzes the critical characteristics, water balance, and evolution of water flux process based on the theory of dualistic water cycle.Referring to the water cycle in the Haihe River basin, a schematic diagram was drawn to describe the dualistic water cycle pattern.Ten different parameters affecting mainly the evolution of water flux in the "dualistic water cycle" are closely examined using the newly-collected data.As a result, this paper proposes several water management and control strategies to achieve healthy wa-ter status for the Haihe River basin. 展开更多
关键词 水资源利用 海河流域 循环模式 二元 演化 家庭生活 现代工业 水资源管理
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Theories and calculation methods for regional objective ET 被引量:4
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作者 QIN DaYong LU JinYan +1 位作者 LIU JiaHong wang mingna 《Chinese Science Bulletin》 SCIE EI CAS 2009年第1期150-157,共8页
The regional objective ET (Evapotranspiration) is a new concept in water resources research,which refers to the total amount of water that could be exhausted from a region in the form of vapor per year. The objective-... The regional objective ET (Evapotranspiration) is a new concept in water resources research,which refers to the total amount of water that could be exhausted from a region in the form of vapor per year. The objective-ET based water resources management allocates water to different regions in terms of ET. It controls the water exhausted from a region to meet the objective ET. The regional objective ET must be adapted to fit the region’s local available water resources. By improving the water utilization effi-ciency and reducing the unrecoverable water in the social water circle,it is saved so that water related production is maintained or even increased under the same water consumption conditions. Regional water balance is realized by rationally deploying the available water among different industries,adjusting industrial structures,and adopting new water-saving technologies,therefore to meeting the requirements for groundwater conservation,agricultural income stability,and avoiding environmental damages. Furthermore,water competition among various departments and industries (including envi-ronmental and ecological water use) may be avoided. This paper proposes an innovative definition of objective ET,and its principles,sub-index systems. Besides,a computational method for regional ob-jective ET is developed by combining the distributed hydrological model and the soil moisture model. 展开更多
关键词 蒸发作用 水资源管理 分布式水文学模型 土壤潮湿模型
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Theories and calculation methods for regional objective ET(evapotranspiration):Applications 被引量:2
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作者 LIU JiaHong QIN DaYong +3 位作者 wang mingna LüJinYan SANG XueFeng ZHANG RuiMei 《Science China(Technological Sciences)》 SCIE EI CAS 2009年第5期1390-1396,共7页
The regional objective ET(evapotranspiration) is defined as the quantity of water that could be con-sumed in a particular region.It varies with the water conditions and economic development stages in the region.It is ... The regional objective ET(evapotranspiration) is defined as the quantity of water that could be con-sumed in a particular region.It varies with the water conditions and economic development stages in the region.It is also constrained by the requirement of benign environment cycle.At the same time,it must meet the demands of sustainable economic growth and the construction of harmony society.Objective ET based water resources distribution will replace the conventional method,which empha-sizes the balance between the water demand and the water supply.It puts focus on the reasonable water consumption instead of the forecasted water demand,which is usually greater than the actual one.In this paper,we calculated the objective ET of 2010 year level in Tianjin by an analysis-integra-tion-assessment method.Objective ET can be classified into two parts:controllable ET and uncontrol-lable ET.Controllable ET includes the ET from irrigation land and the ET from resident land,among which the former can be calculated with soil moisture model and evapotranspiration model,while the latter can be calculated by water use ration and water consumption rate.The uncontrollable ET can be calculated with the distributed hydrological model and the remote sensing monitoring model.The two models can be mutually calibrated.In this paper,eight schemes are put forward based on different portfolios of water resources.The objective ET of each scheme was calculated and the results were assessed and analyzed.Finally,an optimal scheme was recommended. 展开更多
关键词 objective ET(evapotranspiration) water RESOURCES MANAGEMENT application TIANJIN
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Some Highlights of the Grand Rally to Celebrate the 70th Anniversary of the Founding of the People’s Republic of China
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作者 wang mingna 《Peace》 2019年第3期6-8,共3页
President Xi Jinping,also General Secretary of the Communist Party of China(CPC)Central Committee and Chairman of the Central Military Commission,delivers a speech at the Tian’anmen rostrum in Beijing,Oct 1,2019.
关键词 SOME HIGHLIGHTS the GRAND Rally the 70th ANNIVERSARY
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