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LAMINAR FLUID FLOW IN HELICAL ELLIPTICAL PIPE

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Journal of Hydrodynamics 2000年第2期12卷 62-71页

作者： zhang, jinsuo zhang, Benzhao Zhejiang Univ Hangzhou China

By means of an orthogonal curvilinear coordinate system and the solution of complete N-S equations, the flow in a helical elliptical duct was analyzed by the perturbation method. The first-order solutions of the stream function, the axial velocity and the velocity of secondary flow were obtained. The effects of torsion, curvature and axial pressure gradient on the secondary flow were discussed. The torsion has first-order effect on the secondary flow in a helical elliptical pipe, and the secondary flow is dominated by torsion when the axial pressure gradient is small. For increasing gradient the secondary flow is eventually dominated by the effect due to curvature. The fact that the torsion has no effect on fluid flow in a helical pipe with a circular cross section was also confirmed. The most important conclusion is that the flow in a helical elliptical pipe to the first order can be obtained as a combination of the flow in a toroidal pipe and the flow in a twisted pipe.

关键词： Flow of fluids Laminar flow Perturbation techniques Torsional stress

E-pO^(2–) diagram for rare earth elements in molten salt

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Journal of Rare Earths 2017年第2期35卷 187-192页

作者： Yixing(Kevin) Shen jinsuo zhang Niuclear Engineering Program Department of Mechanical and Aerospace Engineering The Ohio State University US

Electro-reduction of spent nuclear oxide fuels in molten salt was the key step of pyroprocessing for oxide fuel treatment. In the present study, the E-pO^2- diagram for rare earth elements in molten Li Cl-KCl at 450 oC were developed based available experimental data. E-pO^2- diagrams could show the stability of each chemical compound in the salt, and therefore, the diagrams could be applied to predict experimental conditions for electro-reduction of spent nuclear fuel efficiently. Compared with the available E-pO^2-diagrams, the present study concerned the activity coefficient of the element studied in the molten salt in all reactions, which made the diagram be more reliable and accurate.

关键词： E-pO^2- Diagram molten salt pyroprocessing fuel cycle rare earths

Study on the mechanism and reaction characteristics of metal-supported phosphogypsum as oxygen carrier in a chemical looping gasification application

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Journal of Environmental Sciences 2024年第4期138卷 428-438页

作者： Jing Yang Yujie Ren Shuoyu Chen jinsuo Lu School of Environmental and Municipal Engineering Xi’an University of Architecture and TechnologyXi’an 710055China

This study aimed to explore the chemical looping gasification(CLG)reaction characteristics of the metal-supported composite phosphogypsum(PG)oxygen carriers(OCs)and the thermodynamic *** FactSage 7.1 thermodynamic simulation was used to explore the oxygen release and H_(2)S removal *** experimental results showed that the syngas yield of CLG with PG-CuFe_(2)O_(4)was more than that with PG-Fe_(2)O_(3)20/CuO40 or PG-Fe_(2)O_(3)30/CuO30 OC at 1023 K when the water vapor content was ***,the maximum syngas yield of the CO selectivity was 70.3% and of the CO_(2)selectivity was 23.8%.The H_(2)/CO value was 0.78,and the highest carbon conversion efficiency was 91.9% in PG-CuFe_(2)O_(4)at the gasification temperature of 1073 *** metal-supported PG composite oxygen carrier was proved not only as an oxygen carrier to participate in the preparation of syngas but also as a catalyst to catalyze coal gasification ***,both the experimental results and FactSage 7.1 thermodynamic analysis revealed that the trapping mechanism of H_(2)S by composite OCs was as follows:CuO first lost lattice oxygen as an oxygen carrier to generate Cu_(2)O,which,in turn,reacted with H_(2)S to generate Cu_(2)*** study provided efficient guidance and reference for OC design in CLG.

关键词： Metal-supported composite phosphogypsum Reaction characteristics Thermodynamic mechanism Chemical looping gasification

A benchmark-based method for evaluating hyperparameter optimization techniques of neural networks for surface water quality prediction

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Frontiers of Environmental Science & Engineering 2024年第5期18卷 13-27页

作者： Xuan Wang Yan Dong Jing Yang Zhipeng Liu jinsuo Lu School of Environmental and Municipal Engineering Xi’an University of Architecture and TechnologyXi’an710055China Shaanxi Key Laboratory of Environmental Engineering Xi’an University of Architecture and TechnologyXi’an710055China State Key Laboratory of Green Building in West China Xi’an University of Architecture and TechnologyXi’an710055China

Neural networks(NNs)have been used extensively in surface water prediction tasks due to computing algorithm improvements and data *** essential step in developing an NN is the hyperparameter *** practice,it is common to manually determine hyperparameters in the studies of NNs in water resources *** may result in considerable randomness and require significant computation time;therefore,hyperparameter optimization(HPO)is *** study adopted five representatives of the HPO techniques in the surface water quality prediction tasks,including the grid sampling(GS),random search(RS),genetic algorithm(GA),Bayesian optimization(BO)based on the Gaussian process(GP),and the tree Parzen estimator(TPE).For the evaluation of these techniques,this study proposed a method:first,the optimal hyperparameter value sets achieved by GS were regarded as the benchmark;then,the other HPO techniques were evaluated and compared with the benchmark in convergence,optimization orientation,and consistency of the optimized *** results indicated that the TPE-based BO algorithm was recommended because it yielded stable convergence,reasonable optimization orientation,and the highest consistency rates with the benchmark *** optimization consistency rates via TPE for the hyperparameters hidden layers,hidden dimension,learning rate,and batch size were 86.7%,73.3%,73.3%,and 80.0%,*** the evaluation of HPO techniques directly based on the prediction performance of the optimized NN in a single HPO test,the proposed benchmark-based HPO evaluation approach is feasible and robust.

关键词： Neural networks Hyperparameter optimization Surface water quality prediction Bayes optimization Genetic algorithm

2021年呼和浩特市大气PM_(2.5)中重金属及类金属污染特征、来源分析及健康风险评价

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实用预防医学 2024年第6期31卷 661-666页

作者：武多多杨升美蒲云霞魏娜娜杨剑业张晨光岳宣志李欢张雯宇贾芯芮韩见弘张学泽张金锁王文瑞范耀春内蒙古科技大学包头医学院内蒙古包头014040 内蒙古自治区综合疾病预防控制中心内蒙古呼和浩特010080 内蒙古医科大学内蒙古呼和浩特010059 内蒙古自治区环境监测总站呼和浩特分站内蒙古呼和浩特010000 呼和浩特市回民区疾病预防控制中心内蒙古呼和浩特010030 呼和浩特市赛罕区疾病预防控制中心内蒙古呼和浩特010020

目的了解呼和浩特市大气中PM_(2.5)中重金属及类金属的污染特征,分析主要来源,评估其健康危害水平。方法2021年,按月在呼和浩特市城区进行空气PM_(2.5)采样,分析质量浓度特征及变化规律。通过主成分分析法对12种金属及类金属的来源进行... 详细信息

目的了解呼和浩特市大气中PM_(2.5)中重金属及类金属的污染特征,分析主要来源,评估其健康危害水平。方法2021年,按月在呼和浩特市城区进行空气PM_(2.5)采样,分析质量浓度特征及变化规律。通过主成分分析法对12种金属及类金属的来源进行解析;用美国环保署的健康风险评估模型对其中9种污染物进行健康风险评价。结果在收集到的146份样本中,PM_(2.5)、As、Ni、Mn分别有41、2、1、7份超过了标准限值,Cr超标103份(占70.55%),实际超标7.4倍;PM_(2.5)中重金属及类金属主要来源有燃煤源、交通源、钢铁冶金工业源和地壳源;非致癌健康风险水平较低。As和Cr致癌风险均处于10^(-6)~10^(-4),潜在致癌风险。结论呼和浩特市大气PM_(2.5)及其重金属、类金属的质量浓度在采暖期较高,且PM_(2.5)中重金属及类金属的主要来源为复合源,需多方面加强管控措施。成年人健康风险随着年龄的增加而增加,60岁以上老人、儿童的健康风险水平均较高。

关键词： PM_(2.5) 重金属类金属来源分析健康风险评价

The Two-person Double-price Second-hand Vehicle Trade Game Model of Quality Certification Market in China

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Journal of Systems Science and Information 2007年第4期5卷 353-364页

作者： Xinping Wang Xinmei Liu jinsuo zhang Management School Xi＇an Jiao Tong University Xi＇an 710049 China Management School Xi＇an University of Science and Technology Xi＇an 710054 China

基于地理探测器的中国碳排放时空分布特征及驱动因素研究

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生态经济 2022年第7期38卷 13-20,27页

作者：田娟娟张金锁西安科技大学能源学院陕西西安710054 西安科技大学能源经济与管理研究中心陕西西安710054 延安大学经济管理学院陕西延安716000

基于30个省份的面板数据,分别运用探索性空间数据分析法及地理探测器考察了我国省域碳排放时空分布特征与驱动因素,结果表明:(1)我国碳排放空间分异及空间相关特征显著,初期呈现“西低东高”“北高南低”特征,而后高值区逐渐向东南及西... 详细信息

基于30个省份的面板数据,分别运用探索性空间数据分析法及地理探测器考察了我国省域碳排放时空分布特征与驱动因素,结果表明:(1)我国碳排放空间分异及空间相关特征显著,初期呈现“西低东高”“北高南低”特征,而后高值区逐渐向东南及西北省份移动。(2)碳排放热点区主要聚集于华北、长三角、河南、山东等地,冷点聚集程度逐年下降。(3)经济发展、环境规制及固定资产投资是碳排放空间分异的主要驱动因子,产业结构的解释力度最小,且多数因子在与其他因子空间叠加后会产生非线性增强作用。(4)经济发展、人口规模、产业结构、能源强度、固定资产投资、外商投资的高值区,碳排放量均处于较高水平。

关键词：碳排放空间相关性地理探测器驱动因素

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扇环形截面弯曲管道内的粘性流动

空气动力学学报 2000年第2期18卷 216-221页

作者：章本照张金锁浙江大学杭州310027

本文利用涡量流函数法系统地研究了扇环形截面弯曲管道内的二次流动 ,计算结果表明了采用控制体积积分法对涡量流函数方程进行离散来求解弯曲管道内粘性流动问题是成功的 ,这样可以避免对压力项的处理 ;对所得结果的分析揭示了该二... 详细信息

本文利用涡量流函数法系统地研究了扇环形截面弯曲管道内的二次流动 ,计算结果表明了采用控制体积积分法对涡量流函数方程进行离散来求解弯曲管道内粘性流动问题是成功的 ,这样可以避免对压力项的处理 ;对所得结果的分析揭示了该二次流动不仅受雷诺数和曲率影响 ,而且扇形中心角。

关键词：曲线管道二次流动涡量-流函数法

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晋陕蒙采矿业绿色全要素生产率实证研究

生态经济 2022年第9期38卷 95-102页

作者：蔡林美郭佐宁张金锁西安科技大学能源学院陕西西安710054 延安大学经济与管理学院陕西延安716000 陕煤集团陕北矿业有限公司陕西榆林719000

晋陕蒙作为黄河流域重要的能源富集区,其采矿业高质量发展对黄河流域采矿业高质量发展至关重要。科学测算GTFP能客观描述科技进步与创新、规模收益等对产出增长的驱动/阻碍情况,为其高质量发展指明方向。然而,现有采矿业GTFP研究较少将... 详细信息

晋陕蒙作为黄河流域重要的能源富集区,其采矿业高质量发展对黄河流域采矿业高质量发展至关重要。科学测算GTFP能客观描述科技进步与创新、规模收益等对产出增长的驱动/阻碍情况,为其高质量发展指明方向。然而,现有采矿业GTFP研究较少将经济、能源、环境因素同时考虑在内,导致测算的GTFP与实际有一定差距。为此,将能源消费量与CO_(2)排放同时纳入研究框架,采用SBM模型测算出考虑CO_(2)与不考虑CO_(2)排放的平均技术效率值,在此基础上运用GML指数测算出2000—2018年晋陕蒙采矿业5个细分行业GTFP,并按区域与时间进行分解。研究发现:该区域采矿业高效发展与绿色生产间的协调、可持续性较差;技术进步是采矿业GTFP增长的源泉,纯技术效率与规模效率是技术效率降低的主因,且前者的阻滞作用更大。考察期内,采矿业GTFP年均增长率为1.2%,除黑色金属矿选业年均增长率为-0.4%,石油与天然气开采业为0,剩余细分行业均为正增长。晋陕蒙要继续增强科技创新能力,协同改善技术效率,助力实现黄河流域采矿业高质量发展目标。

关键词：非期望产出采矿业 GML生产率指数绿色全要素生产率