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Re-examination of Tropical Cyclone Formation in Monsoon Troughs over the Western North Pacific

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Advances in Atmospheric Sciences 2015年第7期32卷 924-934页

作者： zong huijun WU Liguang Pacific Typhoon Research Center and Key Laboratory of Meteorological Disaster of Ministry of Education Nanjing University of Information Science and Technology State Key Laboratory of Severe Weather Chinese Academy of Meteorological Sciences

The monsoon trough （MT） is one of the large-scale patterns favorable for tropical cyclone （TC） formation over the western North Pacific （WNP）. This study re-examines TC formation by treating the MT as a large-scale background for TC activity during May-October. Over an 11-year （2000-10） period, 8.3 TC formation events on average per year are identified to occur within MTs, accounting for 43.1% of the total TC formation events in the WNP basin. This percentage is much lower than those reported in previous studies. Further analysis indicates that TC formation events in monsoon gyres were included at least in some previous studies. The MT includes a monsoon confluence zone where westerlies meet easterlies and a monsoon shear line where the trade easterlies lie north of the monsoon westerlies. In this study, the large-scale flow pattern associated with TC formation in the MT is composited based on the reference point in the confluence zone where both the zonal and meridional wind components are zero with positive vorticity. While previous studies have found that many TCs form in the confluence zone, the composite analysis indicates that nearly all of the TCs formed in the shear region, since the shear region is associated with stronger low-level relative vorticity than the confluence zone. The prevailing easterly vertical shear of zonal wind and barotropic instability may also be conducive to TC formation in the shear region, through the development of synoptic-scale tropical disturbances in the MT that are necessary for TC formation.

关键词： monsoon trough tropical cyclone formation summer monsoon vertical wind shear

Idealized Numerical Simulations of Tropical Cyclone Formation Associated with Monsoon Gyres

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Advances in Atmospheric Sciences 2014年第2期31卷 305-315页

作者： LIANG Jia WU Liguang zong huijun Key Laboratory of Meteorological Disasters of the Ministry of Education Nanjing University of Information Science and Technology State Key Laboratory of Severe Weather Chinese Academy of Meteorological Sciences

Monsoon gyres have been identified as one of the important large-scale circulation patterns associated with tropical cyclone （TC） formation in the western North Pacific.A recent observational analysis indicated that most TCs form near the center of monsoon gyres or at the northeast end of the enhanced low-level southwesterly flows on the southeast-east periphery of monsoon *** the present reported study,idealized numerical experiments were conducted to examine the tropical cyclogenesis associated with Rossby wave energy dispersion with an initial idealized monsoon *** numerical simulations showed that the development of the low-level enhanced southwesterly flows on the southeasteast periphery of monsoon gyres can be induced by Rossby wave energy *** convective systems emerged from the northeast end of the enhanced southwesterly flows with mid-level maximum relative *** simulated TC formed in the northeast of the monsoon gyre and moved westward towards the center of the monsoon *** numerical experiment with a relatively smaller sized initial monsoon gyre showed the TC forming near the center of the initial monsoon *** results of the present study suggest that Rossby wave energy dispersion can play an important role in TC formation in the presence of monsoon gyres.

关键词： monsoon gyre tropical cyclone formation idealized numerical simulation

最低工资标准、劳动力市场分割与资源配置效率

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产业经济研究 2020年第4期 74-89页

作者：宗慧隽李真山东财经大学国际经贸学院山东济南250014

从劳动力市场分割角度探讨了最低工资标准上涨对资源配置效率的影响。通过使用中国1998—2013年284个地级市的工业企业数据,以企业加成率离散度刻画了资源配置效率。实证研究发现:最低工资标准上涨能有效降低企业加成率离散度,提高资源... 详细信息

从劳动力市场分割角度探讨了最低工资标准上涨对资源配置效率的影响。通过使用中国1998—2013年284个地级市的工业企业数据,以企业加成率离散度刻画了资源配置效率。实证研究发现:最低工资标准上涨能有效降低企业加成率离散度,提高资源配置效率;而劳动力市场分割会抑制最低工资标准上涨对资源配置效率的改善作用,相比于劳动力市场分割程度较高的地区,最低工资标准上涨对劳动力市场分割程度较低地区的资源配置效率产生更明显的改善效果。该研究结论在考虑内生性问题、更换资源配置效率度量方式等多种稳健性检验后均成立。进一步的机制检验发现,最低工资标准上涨通过对企业加成率的非对称影响和促进低加成率企业退出市场两个渠道影响资源配置效率,而且该影响作用在劳动力市场分割程度较低地区更大。因此,提高最低工资标准及降低劳动力市场分割程度的政策有助于改善资源配置效率。

关键词：最低工资标准劳动力市场分割企业加成率企业加成率离散度资源配置效率

Constructal design of a rectangular parallel phase change microchannel in a three-dimensional electronic device

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Science China(Technological Sciences) 2024年第5期67卷 1381-1390页

作者： ZHANG JiWen FENG huijun CHEN LinGen GE YanLin Institute of Thermal Science and Power Engineering Wuhan Institute of TechnologyWuhan430205China College of Power Engineering Naval University of EngineeringWuhan430033China Hubei Provincial Engineering Technology Research Center of Green Chemical Equipment Wuhan430205China School of Mechanical&Electrical Engineering Wuhan Institute of TechnologyWuhan430205China

Based on constructal theory,a rectangular parallel phase change microchannel model in a three-dimensional electronic device(TDED)is established with R134a as the cooling *** on the minimization of a complex function(CF)composed of linear weighting sum of maximum temperature difference and pumping power consumption,constructal design of the TDED is conducted first;and then,maximum temperature difference and pumping power consumption are minimized by non-dominated sorting genetic algorithm-II *** results reveal that there exist an optimal mass flow rate(0.0012 kg/s)and a quadratic optimal aspect ratio(AR)(0.39)of the microchannel which lead to quadratic minimum CF(0.817).Compared with the original value,the CF after optimization is reduced by 18.34%.Reducing the inlet temperature of cooling fluid and microchannel number appropriately can help to enhance the overall performance of *** using the artificial neural network and genetic algorithms in the toolboxes of Matlab software,the optimal AR gained in the Pareto solution set is located between 0.2–*** smallest deviation index among three discussed strategies is 0.346,and the corresponding optimal AR is 0.413,which is selected as the optimal design strategy of the microchannel in the TDED under multiple *** findings in this study can serve as theoretical guides for thermal designs of electronic devices.

关键词： constructal theory parallel microchannel evaporation phase change three-dimensional electronic device multi-objective optimization artificial neural network

The startup and production of the No.4 slab continuous caster at Baosteel

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Baosteel Technical Research 2008年第3期2卷 60-64页

作者： Zhi Jianjun Yu Zuda Hou Angui Wang Hongbing Hu huijun zong Zhenyu Steelmaking Plant Baosteel Branch Baoshan Iron ＆ Steel Co. Ltd. Shanghai 200941 China

In order to meet the developing requirements for the output and quality of the products of Baosteel, the No. 4 slab continuous caster designed by the Danieli Company of Italy was built. Since starting up in December, 2006, the casting machine has run smoothly in the aspects of production and quality control. It is equipped with advanced apparatus and technology, such as electric magnetic braking （EMBR） and soft reduction. Some operation indices have been continually improved, in order to ensure that slab quality meets the requirements of downstream products. Its total output reached 2.17 Mt in 2007. This study analyzes the operational indices and the slab quality.

关键词： slab continuous casting product variety quality

Constructal design of a rectangular porous fin considering minimization of maximum temperature difference and pumping power consumption

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Science China(Technological Sciences) 2024年第3期67卷 919-929页

作者： LIU XiaoYe FENG huijun CHEN LinGen GE YanLin Institute of Thermal Science and Power Engineering Wuhan Institute of TechnologyWuhan 430205China College of Power Engineering Naval University of EngineeringWuhan 430033China Hubei Provincial Engineering Technology Research Center of Green Chemical Equipment Wuhan 430205China School of Mechanical&Electrical Engineering Wuhan Institute of TechnologyWuhan 430205China

A heat dissipation model of a rectangular porous fin is established based on constructal theory. First, the constructal design of rectangular porous fin is conducted by selecting a complex function minimization, which composed of linear weighting sum of maximum temperature difference and pumping power consumption, as optimization objective. Effects of gap height, air inlet velocity, total porous fin volume and porosity on the optimal constructs are investigated, respectively. The findings show that the complex function can attain its double minimum at a value of 0.802 when the fin length and number are optimized, and the corresponding optimal fin length and number are 8.01 mm and 10, respectively. In comparison to original design, the complex function and maximum temperature difference after twice optimization are decreased by 19.80% and 66.31%, ***, the comprehensive performance of porous fin is improved by simultaneously optimizing the fin length and number. The artificial neural network is applied to predict the fin performances, which is used to conduct multi-objective optimization based on NSGA-II algorithm. Optimal structure of porous fin for multiple requirements is gained by LINMAP and TOPSIS decisionmaking strategies. The findings in this study can serve as theoretical guides for fin thermal designs of electronic devices.

关键词： constructal theory rectangular porous fin pumping power consumption maximum temperature difference complex function multi-objective optimization

Record-breaking summer-autumn drought in southern China in 2022:Roles of tropical sea surface temperature and Eurasian warming

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Science China Earth Sciences 2024年第2期67卷 420-431页

作者： Yuepeng HU Botao ZHOU huijun WANG Dapeng ZHANG Collaborative Innovation Center on Forecast and Evaluation of Meteorological Disasters/Key Laboratory of Meteorological Disaster Ministry of Education/Joint International Research Laboratory of Climate and Environment ChangeNanjing University of Information Science and TechnologyNanjing210044China School of Atmospheric Sciences Nanjing University of Information Science and TechnologyNanjing210044China

From summer to autumn in 2022,a severe drought lasted in southern China,posing serious effects on economic growth and ecological *** study explored the atmospheric circulations accounting for this persistent drought *** shows that the drought in southern China during the summer of 2022 was strongly linked to the divergence of water vapor flux and descending motions,which were respectively caused by the anomalous anticyclone over the western North Pacific and the northward movement of the East Asian subtropical jet(EASJ).Differently,the atmospheric background responsible for the sustained drought in autumn is manly featured by a cyclonic circulation anomaly over the region from the Bay of Bengal to the South China Sea,which led to decreased moisture and descending motions in southern *** investigation suggests that the rarely strong surface warming over northern Eurasia and the extreme La Nina-like pattern over the tropical Pacific jointly resulted in the anomalous anticyclone over the western North Pacific and the northward shift of the EASJ in the summer of 2022,while the cyclonic circulation anomaly prevailing over the region from the Bay of Bengal to the South China Sea in autumn was largely attributed to the extremely negative anomalies of the tropical Indian Ocean sea surface temperature.

关键词： Summer-autumn drought Southern China Tropical sea surface temperature Eurasian warming

Energy and exergy analyses and optimizations for two-stage TEC driven by two-stage TEG with Thomson effect

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Science China(Technological Sciences) 2024年第4期67卷 1077-1093页

作者： CHEN LinGen GE YanLin FENG huijun REN TingTing Institute of Thermal Science and Power Engineering Wuhan Institute of TechnologyWuhan 430205China Hubei Provincial Engineering Technology Research Center of Green Chemical Equipment Wuhan 430205China School of Mechanical&Electrical Engineering Wuhan Institute of TechnologyWuhan 430205China

Based on the non-equilibrium thermodynamics and energy and exergy analyses,a thermodynamic model of two-stage thermoelectric(TE)cooler(TTEC)driven by two-stage TE generator(TTEG)(TTEG-TTEC)combined TE device is established with involving Thomson effect by fitting method of variable physical parameters of TE *** total number of TE elements as constraint,influences of number distributions of TE elements on three device performance indictors,that is,cooling load,maximum COP and maximum exergetic efficiency,are *** number distributions of TE elements are optimized with three maximum performance indictors as the objectives,*** of hot-junction temperature of TTEG and coldjunction temperature of TTEC on optimization results are analyzed,and difference between optimization results corresponding to three performance indicators are *** performance intervals and optimal variable intervals are *** of Thomson effect on three general performance indicators,three optimal performance indicators and optimal variables are comparatively *** effect reduces three general performance indicators and three optimal performance indicators of *** hot-and cold-junction temperatures of TTEG and TTEC are 450,305,325 and 295 K,respectively,Thomson effect reduced maximum cooling load,maximum COP and maximum exergetic efficiency from 9.528 W,9.043×10^(-2)and2.552%to 6.651 W,6.286×10^(-2)and 1.752%,respectively.

关键词： non-equilibrium thermodynamics cooling load COP exergetic efficiency combined thermoelectric device performance optimization

Clinical observation on 90 cases of primary dysmenorrhea treated by buccal acupuncture therapy:a randomized controlled study

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Journal of Traditional Chinese Medicine 2024年第1期44卷 172-181页

作者： YANG Yi YE huijun ZHENG Huiling JIN Lihua Department of Obstetrics and Gynecology the Second Affiliated Hospital of Zhejiang Chinese Medical UniversityXinhua Hospital of Zhejiang ProvinceHangzhou 310005China

OBJECTIVE:To explore the short-term and long-term efficacy of buccal acupuncture therapy in the treatment of patients with primary dysmenorrhea(PD).METHODS:A total of 90 patients with PD who were admitted to the Second Affiliated Hospital of Zhejiang University of Traditional Chinese Medicine from January 2020 to December 2021 were included in this study and randomly divided into three groups,including the observation group,the control group,and the placebo group,with 30 patients in each *** in the observation group were treated according to the syndrome types of Traditional Chinese Medicine,those in the control group were treated with Saridon,and those in the placebo group received a *** visual analog scale(VAS)scores of these patients were evaluated at different time points(before treatment,5 min after needle retention,30 min after needle retention,1 h after treatment,2 h after treatment,1 d after treatment,and 2 d after treatment).The Cox Menstrual Symptom Scale(CMSS)scores were assessed before the treatment and after three courses of ***,these two scales were also evaluated during ***,the pain score and adverse reactions of these patients were assessed during ***:After treatment,the VAS and CMSS scores in the observation group decreased significantly(P<0.05)5 and 30 min after needle retention and after ***:Buccal acupuncture therapy is verified to have short-term efficacy in the treatment of *** addition,this therapy has an immediate analgesic effect and long-term efficacy in reducing the severity and frequency of PD.

关键词： buccal acupuncture therapy primary dysmenorrhea pain score randomized controlled trial