检索结果-南通市图书馆

超导磁储能装置提高柔性直流配电系统稳定性的研究

在线全文

学校读者我要写书评

暂无评论

电源学报 2024年第2期22卷 250-262页

作者：李岚丁安敏田洪英张彦张奎同马文忠中国石油大学(华东)新能源学院青岛266580 山东能源集团济南273500

柔性直流配电系统中定功率控制的换流器具有恒功率负载特性,会降低系统阻尼,对系统的稳定性产生不利影响。针对该问题,在直流配电系统中加入超导磁储能SMES(superconducting magnetic energy storage)装置来提高系统的稳定性。推导了柔... 详细信息

柔性直流配电系统中定功率控制的换流器具有恒功率负载特性,会降低系统阻尼,对系统的稳定性产生不利影响。针对该问题,在直流配电系统中加入超导磁储能SMES(superconducting magnetic energy storage)装置来提高系统的稳定性。推导了柔性直流配电系统的反馈控制模型,采用频域分析法研究了换流器恒功率负载特性对系统稳定性的影响,并结合数学模型和频域分析,指出SMES装置能够为电网提供正阻尼,增大了系统开环传递函数在剪切频率处的相位裕度,从而改善了系统稳定性。为防止超导磁体两端电压过高,SMES装置与直流配电网连接的DC/DC换流器需具备一定的电压调节性能,因此研究了采用模块化多电平DC/DC换流器DC-MMC(modular multilevel DC/DC converter)的SMES装置,通过调节子模块个数灵活设置换流器电压变比,在实现换流器能量双向流动的同时控制超导磁体两端电压,以保护储能装置。最后通过时域仿真波形验证了采用DC-MMC的SMES装置在提高柔性直流配电系统稳定性方面的可行性和有效性。

关键词：柔性直流配电系统超导磁储能小信号稳定性反馈控制模型模块化多电平DC/DC换流器

The Influence of Meridional Variation in North Pacific Sea Surface Temperature Anomalies on the Arctic Stratospheric Polar Vortex

在线全文

学校读者我要写书评

暂无评论

Advances in Atmospheric Sciences 2023年第12期40卷 2262-2278页

作者： Tao WANG Qiang FU Wenshou tian Hongwen LIU Yifeng PENG Fei XIE hongying tian Jiali LUO College of Atmospheric Sciences Lanzhou UniversityLanzhou 730000China Key Laboratory of Western China's Environmental Systems of the Ministry of Education College of Earth and Environmental SciencesLanzhou UniversityLanzhou 730000China Department of Atmospheric Sciences University of WashingtonSeattle 98101USA College of Global Change and Earth System Science Beijing Normal UniversityBeijing 100875China

This study examines the dependence of Arctic stratospheric polar vortex(SPV)variations on the meridional positions of the sea surface temperature(SST)anomalies associated with the first leading mode of North Pacific *** principal component 1(PC1)of the first leading mode is obtained by empirical orthogonal function *** data,numerical experiments,and CMIP5 model outputs all suggest that the PC1 events(positive-minus-negative PC1 events),located relatively northward(i.e.,North PC1 events),more easily weaken the Arctic SPV compared to the PC1 events located relatively southward(i.e.,South PC1 events).The analysis indicates that the North PC1-related Aleutian low anomaly is located over the northern North Pacific and thus enhances the climatological trough,which strengthens the planetary-scale wave 1 at mid-to-high latitudes and thereby weakens the *** weakened stratospheric circulation further extends into the troposphere and favors negative surface temperature anomalies over *** contrast,the South PC1-related Aleutian low anomaly is located relatively southward,and its constructive interference with the climatological trough is less efficient at high ***,the South PC1 events could not induce an evident enhancement of the planetary-scale waves at high latitudes and thereby a weakening of the SPV on *** Eurasian cooling associated with South PC1 events(positive-minus-negative PC1 events)is also not *** results of this study suggest that the meridional positions of the PC1 events may be useful for predicting the Arctic SPV and Eurasian surface temperature variations.

关键词： Arctic stratospheric polar vortex stratosphere-troposphere interactions North Pacific sea surface temperature Aleutian low

Impact of intensity variability of the Asian summer monsoon anticyclone on the chemical distribution in the upper troposphere and lower stratosphere

在线全文

学校读者我要写书评

暂无评论

Atmospheric and Oceanic Science Letters 2022年第3期15卷 25-30页

作者： Kecheng Peng Jiali Luo Jiayi Mu Xiaoqun Cao hongying tian Lin Shang Yanan Guo College of Meteorology and Oceanography National University of Defense TechnologyChangshaChina Key Laboratory of Semi-Arid Climate Change and College of Atmospheric Sciences Lanzhou UniversityLanzhouChina College of Computer National University of Defense TechnologyChangshaChina Shandong Provincial Climate Center JinanChina Trainer Simulation Training Center of Naval Aeronautical University HuludaoChina

亚洲夏季风期,平流层-对流层物质交换过程能显著影响上对流层下平流层化学成分的浓度变化和空间分布.然而,亚洲夏季风反气旋强度的季节内变化对其内部和周围地区化学成分水平分布的影响尚不清楚.本文将亚洲夏季风反气旋划分为季节内强... 详细信息

亚洲夏季风期,平流层-对流层物质交换过程能显著影响上对流层下平流层化学成分的浓度变化和空间分布.然而,亚洲夏季风反气旋强度的季节内变化对其内部和周围地区化学成分水平分布的影响尚不清楚.本文将亚洲夏季风反气旋划分为季节内强周期和弱周期,发现当亚洲夏季风反气旋更强时,100 hPa O_(3)低值区的面积更大,O_(3)浓度更低.但是这种影响主要体现在6月份,7,8月的O_(3)水平分布还受东南亚地区深对流的影响.这些结果表明亚洲夏季风反气旋强度和深对流的季节内变化可以显著影响亚洲夏季风期上对流层下平流层的化学分布.

关键词：亚洲夏季风反气旋强度指数化学成分分布深对流

Cable-driven legged landing gear for unmanned helicopter:Prototype design,optimization and performance assessment

在线全文

学校读者我要写书评

暂无评论

Science China(Technological Sciences) 2024年第4期67卷 1196-1214页

作者： tian BaoLin GAO HaiBo YU HaiTao SHAN HaoMin HOU JunChen YU hongying DENG ZongQuan State Key Laboratory of Robotics and System Harbin Institute of TechnologyHarbin 150001China China Academy of Aerospace Science and Innovation Beijing 100048China

Unmanned helicopters equipped with adaptive landing gear will dramatically extend their application especially in dealing with challenging *** study presents a novel cable-driven legged landing gear(CLG)with differential transmission for unmanned helicopters in complex landing *** obtain the preferred configuration of the legged mechanism,a multi-objective optimization framework for the CLG is constructed by concurrently considering terrain adaptability,landing stability and reasonable linkage of internal *** non-dominated sorting genetic algorithmⅡis employed to numerically acquire the optimal scale parameters that guide the mechanical design of the *** unmanned helicopter prototype equipped with the devised CLG is developed with key performance *** results show that the devised CLG can provide energy-efficient support over uneven terrains(totally driven torque demand less than 0.1 N m)in quasi-static landing tests,and favorable terrain adaptability(posture fluctuation of the fuselage less than±1°)in unknown slope landing *** exhibited merits give the proposed CLG the potential to enhance the landing performance of future aircraft in extreme environments.

关键词： unmanned helicopter adaptive landing gear experimental verification

Nutrient-regulated dynamics of chondroprogenitors in the postnatal murine growth plate

在线全文

学校读者我要写书评

暂无评论

Bone Research 2023年第2期11卷 340-353页

作者： Takeshi Oichi Joe Kodama Kimberly Wilson hongying tian Yuka Imamura Kawasawa Yu Usami Yasushi Oshima Taku Saito Sakae Tanaka Masahiro Iwamoto Satoru Otsuru Motomi Enomoto-Iwamoto Department of Orthopedics School of MedicineUniversity of MarylandBaltimoreMD21201USA Sensory&Motor System Medicine Faculty of MedicineThe University of TokyoBunkyo-kuTokyo1138655Japan Department of Orthopedics Teikyo University School of MedicineTokyo1738608Japan Department of Biochemistry and Molecular Biology Pennsylvania State University College of MedicineHersheyPA17033USA Department of Oral Pathology Osaka University Graduate School of DentistrySuitaOsaka5650871Japan

Longitudinal bone growth relies on endochondral ossification in the cartilaginous growth plate,where chondrocytes accumulate and synthesize the matrix scaffold that is replaced by *** chondroprogenitors in the resting zone maintain the continuous turnover of chondrocytes in the growth *** is a leading cause of growth retardation in children;however,after recovery from nutrient deprivation,bone growth is accelerated beyond the normal rate,a phenomenon termed catch-up *** nutritional status is a known regulator of long bone growth,it is largely unknown whether and how chondroprogenitor cells respond to deviations in nutrient ***,using fate-mapping analysis in Axin2CreERT2 mice,we showed that dietary restriction increased the number of Axin2+chondroprogenitors in the resting zone and simultaneously inhibited their *** nutrient deficiency was resolved,the accumulated chondroprogenitor cells immediately restarted differentiation and formed chondrocyte columns,contributing to accelerated ***,we showed that nutrient deprivation reduced the level of phosphorylated Akt in the resting zone and that exogenous IGF-1 restored the phosphorylated Akt level and stimulated differentiation of the pooled chondroprogenitors,decreasing their *** study of Axin2CreERT2 revealed that nutrient availability regulates the balance between accumulation and differentiation of chondroprogenitors in the growth plate and further demonstrated that IGF-1 partially mediates this regulation by promoting the committed differentiation of chondroprogenitor cells.

关键词： progenitor plate maintain

Fine-tuning the structure-tolerance-antitumor efficacy axis of prodrug nanoassemblies via branched aliphatic functionalization

在线全文

学校读者我要写书评

暂无评论

Nano Research 2024年第4期17卷 2908-2918页

作者： Guanting Li Fengli Xia hongying Xiao Shunzhe Zheng Shuwen Fu Han Qiao Qianhui Jin Xuanbo Zhang Dun Zhou Chutong tian Jin Sun Zhonggui He Bingjun Sun Department of Pharmaceutics Wuya College of InnovationShenyang Pharmaceutical UniversityShenyang 110016China Department of Pharmaceutics College of PharmacyShenyang Pharmaceutical UniversityShenyang 110016China Emergency Department The First Affiliated Hospital of Jinzhou Medical UniversityJinzhou 121001China

Small-molecule prodrug nanoassemblies have emerged as efficient antitumor drug delivery ***,in the case of camptothecins-based prodrug nanoassemblies,linear aliphatic side chain modification often results in rod-shaped or irregularly shaped nanoassemblies,which are highly unfavorable for sterilization through filtration,and may cause capillary blockage upon intravenous *** rational design of camptothecins-based prodrug nanoassemblies remains a ***,we propose that branched aliphatic alcohol(BAA)functionalization could fine-tune the structure-tolerance-antitumor efficacy axis of prodrug ***,four SN38-BAA prodrugs were synthesized by conjugating 7-ethyl-10-hydroxycamptothecin(SN38)with BAAs of varying lengths via a tumor redox-responsive disulfide bond,which self-assemble into uniform spherical *** length of BAA was found to significant impact the multiple drug delivery process,including colloidal stability,drug release profiles and ***,SN38-C21 NPs(SN38-11-heneicosanol nanoparticles),featuring the longest BAA,showcased multiple therapeutic advantages,ultimately culminating the optimal antitumor efficacy and *** findings underscore the potential of BAA functionalization in strengthening the therapeutic outcomes of prodrug nanoassemblies,and provide valuable insights for developing translational camptothecins-based nanomedicines.

关键词： prodrug nanoassembly self-assembly antitumor efficacy tolerance 7-ethyl-10-hydroxycamptothecin(SN_(3)8)

Impacts of the atmospheric apparent heat source over the Tibetan Plateau on summertime ozone vertical distributions over Lhasa

维普期刊数据库评论

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

Atmospheric and Oceanic Science Letters 2021年第3期14卷 66-71页

作者： Wenjun Liang Zhen Yang Jiali Luo hongying tian Zhixuan Bai Dan Li Qian Li Jinqiang Zhang Haoyue Wang Bian Ba Yang Yang Key Laboratory of Semi-Arid Climate Change and College of Atmospheric Sciences Lanzhou UniversityLanzhouChina Key Laboratory of Middle Atmosphere and Global Environment Observation Institute of Atmospheric PhysicsChinese Academy of SciencesBeijingChina Department of Atmospheric Science Yunnan UniversityKunmingChina Atmospheric Observation Centre of Lhasa Meteorological Bureau LhasaChina Institute of Arid meteorology China Meteorological AdministrationLanzhouChina

青藏高原(TP)是一个对气候变化敏感的地区,其上空的臭氧分布影响着青藏高原及其周边地区的大气环境.北半球夏季青藏高原上空臭氧柱总量相对较低的现象,及其时空变化受到广泛关注.本研究利用北半球夏季5年的拉萨上空臭氧的气球测量数据,... 详细信息

青藏高原(TP)是一个对气候变化敏感的地区,其上空的臭氧分布影响着青藏高原及其周边地区的大气环境.北半球夏季青藏高原上空臭氧柱总量相对较低的现象,及其时空变化受到广泛关注.本研究利用北半球夏季5年的拉萨上空臭氧的气球测量数据,研究高原上空大气视热源(Q1)对臭氧垂直分布的影响并探讨了该过程的机制.结果表明,当TP上空对流层整体的Q1相对较高时,拉萨上空对流层臭氧浓度下降.大气更强的上升运动伴随着TP主体区域上空的Q1的增大.因此,当夏季Q1较高时,由于近地表低浓度臭氧空气向上输送,拉萨上空的对流层臭氧浓度下降.

关键词：臭氧青藏高原大气视热源上升运动

我国天然气地下储气库运营与定价模式改进对策研究

在线全文

学校读者我要写书评

暂无评论

价格理论与实践 2022年第7期 191-194页

作者：瞿静川张蓉田红英刘海英中国石油新疆油田分公司

近年来,随着天然气战略地位的提升与天然气行业的进一步发展,天然气储气库业务显现出产权独立化和经营自主化的转变趋势,使得原有定价模式的针对性和有效性降低,并随之出现了诸多运营难题,亟需针对行业发展新形势提出科学合理有效的定... 详细信息

近年来,随着天然气战略地位的提升与天然气行业的进一步发展,天然气储气库业务显现出产权独立化和经营自主化的转变趋势,使得原有定价模式的针对性和有效性降低,并随之出现了诸多运营难题,亟需针对行业发展新形势提出科学合理有效的定价策略。本文通过对国外储气库定价机制的深入剖析与对比研究,结合国家最新出台的储气库相关政策,从国内地下储气库发展面临的市场环境和瓶颈入手,梳理国内储气库运营与定价模式,深入分析地下储气库定价的影响因素。最后,从推进储气设施独立运营模式、优化计价基础、优化成本核算体系、优化动态定价方式、优化效益分配方式等方面提出适合我国地下储气库场景并有利于长期高效发展的定价策略。

关键词：定价策略地下储气库运营管理成本核算

在线全文

学校读者我要写书评

暂无评论

物流企业运输计划优化算法研究

物流技术 2013年第6期32卷 160-163页

作者：田红英成都职业技术学院四川成都610041

为了实现对大型综合物流企业运输计划的优化,针对运输问题的约速和目标,构造了数学求解模型,并设计了一个包含了Dijkstra方法和禁忌算法在内的两阶段算法,最后通过实际验证证明了该算法对解决大型物流企业运输计划非常有效。

关键词：运输计划 Dijkstra方法禁忌算法