检索结果-南通市图书馆

On the loss mechanisms of radiation belt electron dropouts during the 12 September 2014 geomagnetic storm

在线全文

学校读者我要写书评

暂无评论

Earth and Planetary Physics 2020年第6期4卷 598-610页

作者： Xin Ma Zheng Xiang BinBin Ni song fu Xing Cao Man Hua DeYu Guo YingJie Guo XuDong Gu ZeYuan Liu Qi Zhu Department of Space Physics School of Electronic InformationWuhan UniversityWuhan 430072China Chinese Academy of Sciences Center for Excellence in Comparative Planetology Hefei 230026China

Radiation belt electron dropouts indicate electron flux decay to the background level during geomagnetic storms,which is commonly attributed to the effects of wave-induced pitch angle scattering and magnetopause *** investigate the loss mechanisms of radiation belt electron dropouts triggered by a solar wind dynamic pressure pulse event on 12 September 2014,we comprehensively analyzed the particle and wave measurements from Van Allen *** dropout event was divided into three periods:before the storm,the initial phase of the storm,and the main phase of the *** electron pitch angle distributions(PADs)and electron flux dropouts during the initial and main phases of this storm were investigated,and the evolution of the radial profile of electron phase space density(PSD)and the(μ,K)dependence of electron PSD dropouts(whereμ,K,and L^*are the three adiabatic invariants)were *** energy-independent decay of electrons at L>4.5 was accompanied by butterfly PADs,suggesting that the magnetopause shadowing process may be the major loss mechanism during the initial phase of the storm at L>*** features of electron dropouts and 90°-peaked PADs were observed only for>1 MeV electrons at Lfusion.

关键词： radiation belt electron flux dropouts geomagnetic storm electron phase space density magnetopause shadowing wave-particle interactions

Modeling the energetic electron fluxes in the inner radiation belt based on a drift-source model

在线全文

学校读者我要写书评

暂无评论

Earth and Planetary Physics 2023年第1期7卷 100-108页

作者： Zheng Xiang BinBin Ni YangXiZi Liu XuDong Gu song fu Wei Xu Xing Cao Xin Ma DeYu Guo JunHu Dong JingLe Hu Department of Space Physics School of Electronic InformationWuhan UniversityWuhan 430072China

The Macao Science Satellite-1(MSS-1),designed by the Macao University of Science and Technology and the National Space Science Center(NSSC)of China,is equipped to detect the fine structure of the magnetic field over the South Atlantic Anomaly(SAA)region,monitoring geomagnetic field variations,and obtaining the energetic electron spectrum distributions in the Earth’s inner radiation *** this study,we simulate the distributions of trapped,quasi-trapped,and untrapped electrons along the orbit of MSS-1 based on a drift-source *** simulation results show that the particle detector with 90°looking direction can observe trapped electrons in the SAA region,untrapped electrons in the regions conjugated with the SAA region at the north hemisphere,and quasitrapped electrons in all other *** contrast,the detectors with<60°looking directions can measure only untrapped ***,quasi-trapped electron fluxes accumulate along the drift trajectory and are due primarily to CRAND,until reaching the SAA region where quasi-trapped electrons are all lost into the atmosphere.

关键词： Earth’s inner belt drift-source model quasi-trapped electron CRAND

高能核-核碰撞中粒子的(赝)快度分布与重叠柱模型(英文)

在线全文

学校读者我要写书评

暂无评论

高能物理与核物理 2005年第5期29卷 461-466页

作者：宋福刘福虎山西师范大学现代物理研究所临汾041004

应用重叠柱模型描述了高能核-核碰撞中带电粒子的快度(或赝快度)分布.对目前加速器上的固定靶实验而言,观察到了相同相对强度的纵向流,两个完全重叠的热化柱能够描述实验数据.在更高能量范围(4ATeV以上),观察到了更强的纵向流,这时需要... 详细信息

应用重叠柱模型描述了高能核-核碰撞中带电粒子的快度(或赝快度)分布.对目前加速器上的固定靶实验而言,观察到了相同相对强度的纵向流,两个完全重叠的热化柱能够描述实验数据.在更高能量范围(4ATeV以上),观察到了更强的纵向流,这时需要两个部分重叠的热化柱来描述实验数据.用重叠柱模型计算得到的(赝)快度分布与1AGeV到100ATeV能区的实验结果符合.

关键词：重叠柱模型快度分布核-核碰撞加速器热化柱

Studies on Intramolecular Stacking Interaction of Ternary Complexes M（Ⅱ）（ATP）￣（2－） with Heteroaromatic N－Base Ligands

在线全文

学校读者我要写书评

暂无评论

Chemical Research in Chinese Universities 1994年第3期10卷 167-174页

作者： WU fu-liai, song Bin, ZHANG Jie and JI Liang-nian (Chemistiy Department , Biotechnology Research Center, Zhongshan University, Guangzhou, 510275)

o understand the driving forces leading to mixed-ligand complexes in biologi-cal *** complexes of M (ATP(L￣(2-) type, where M = Cu￣(2+), Ni￣(2+) orCo￣(2+) , and L= pyridine(Py) , 4-picoline, 3, 5-lutidine, isoquinoline (lq) or benzimi-dazole(Bi) in aqueous solution were studied by spectropliotometry, some of them(M=Cu￣(2+), L = isoquinoline or benzimidazole) were also separately studied hy po-tentiometric pH titration. The results show that an intramolecular stacking interac-tion exists between the heteroaromatic ring of the ligands and the purine moiety ofATP.

关键词： Stacking interaction Ternary complexes Heteroaromatic N-base ATP

Importance of electron distribution profiles to chorus wave driven evolution of Jovian radiation belt electrons

在线全文

学校读者我要写书评

暂无评论

Earth and Planetary Physics 2018年第5期2卷 371-383页

作者： Jing Huang XuDong Gu BinBin Ni Qiong Luo song fu Zheng Xiang WenXun Zhang Department of Space Physics School of Electronic Information Wuhan University Lunar and Planetary Science Laboratory Macao University of Science and Technology-Partner Laboratory of Key Laboratory of Lunar and Deep Space Exploration Chinese Academy of Sciences

Wave-particle interactions triggered by whistler-mode chorus waves are an important contributor to the Jovian radiation belt electron dynamics. While the sensitivity of chorus-driven electron scattering to the ambient magnetospheric and wave parameters has been investigated, there is rather limited understanding regarding the extent to which the dynamic evolution of Jovian radiation belt electrons, under the impact of chorus wave scattering, depends on the electron distribution profiles. We adopt a group of reasonable initial conditions based upon the available observations and models for quantitative analyses. We find that inclusion of pitch angle variation in initial conditions can result in increased electron losses at lower pitch angles and substantially modify the pitch angle evolution profiles of > ~500 keV electrons, while variations of electron energy spectrum tend to modify the evolution primarily of 1 MeV and 5 MeV electrons. Our results explicitly demonstrate the importance to the radiation belt electron dynamics in the Jovian magnetosphere of the initial shape of the electron phase space density, and indicate the extent to which variations in electron energy spectrum and pitch angle distribution can contribute to the evolution of Jovian radiation belt electrons caused by chorus wave scattering.

关键词： Jovian radiation belt whistler-mode chorus wave-particle interactions electron distribution profile

Static Threshold Pressure Gradient Characteristics of Liquid Influenced by Boundary Wettability

在线全文

学校读者我要写书评

暂无评论

Chinese Physics Letters 2010年第2期27卷 153-156页

作者：宋付权汪建东刘海丽 Department of Physics Zhejiang Normal UniversityJinhua 321004

We propose an experimental setup to measure the threshold pressure gradient （TPG） of microchannels with different wettability surfaces by the static method in microchannels with diameters from 20 μm to 320 μm, and compare the TPG of microchannels with adsorption of cetyl trimethyl ammonium bromide （CTAB） with that without CTAB adsorption. The results show the existence of TPG in microchannels. The TPG of microchannels increases with decreasing hydrodynamic diameter, and the relation between TPG and diameter is in agreement with the single-log normalization. The TPG of a microchannel with CTAB adsorption decreases obviously as compared with the microchannel without CTAB adsorption. The TPG of microchannels with different wettabilities of boundary surface are different, and the resistance of liquid flow can be reduced by changing the wettability of boundary surfaces.

关键词： Soft matter liquids and polymers Fluid dynamics Surfaces interfaces and thin films

Fontan extracardiac tunnel connection： fenestration or not？

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

Chinese Medical Journal 2009年第19期122卷 2335-2338页

作者： fu song Valeske Klaus Akinturk Hakan Schranz Dietmar Department of Childrens' Heart Center BAYI Children's Hospital General Hospital of Beijing Military Command Beijing 100700 China Department of Children's Heart Center Justus-Liebig-University Giessen 35385 Germany

Background The fenestration function is by allowing a right-to-left shunt resulting in an increased cardiac index, associated with mild arterial oxygen desaturation. Subsequent transcatheter fenestration closure can be performed after haemodynamic assessment. The purpose of this study was to compare the outcomes of extracardiac connection （EC） with or without fenestration. Methods Ninety-five consecutive patients diagnosed with univentricular heart disease underwent EC using Gore-Tax conduits at the Department of Children＇s Heart Center, Justus-Liebig-University Giessen Germany from June 1996 to July 2007. According to EC with or without fenestration, the patients were assigned to two groups （group A with fenestration and group B without fenestration）. Mortality, effusions, postoperative mean pulmonary artery pressure, postoperative oxygen saturation, postoperative thrombosis, postoperative neurological problems, and the postoperative loss of sinus rhythm were compared. In group A, 23 patients had fenestration closed interventionally after a mean time of 20-22 months. Results Mortality and postoperative mean pulmonary artery pressure in group B （3 and （15.1±3.4） mmHg, respectively） were significantly higher than group A （0 and （13.2±2.8） mmHg, respectively）. Postoperative oxygen saturation, postoperative thrombosis, postoperative neurological problems, and the postoperative loss of sinus rhythm did not differ between cohorts. Conclusions Fenestrating an extracardiac tunnel seems to improve acute postoperative mortality by rising cardiac output. The induced right-to-left shunt shows no morbidity postoperatively. If a stabilized chronic hemodynamic situation is achieved, an interventional closure of the fenestration can be performed to advance the arterial saturation and improve the exercise tolerance of the patients.

关键词： Fontan tunnel extracardiac connection univentricular heart fenestration

Inhibitory effect of three biopolymer materials on scar formation following trabeculectomy

在线全文

学校读者我要写书评

暂无评论

International Journal of Ophthalmology(English edition) 2011年第4期4卷 380-383页

作者： Sha, Qian Jiao, Guang-Yu Cui, Hai-Bin Wang, Jie Sun, Li-Bin Chen, Ming fu, song-Bin Harbin Med Coll Harbin 150001 Heilongjiang Pr Peoples R China China Med Univ Shengjing Hosp Dept Ophthalmol Shenyang 110004 Liaoning Provin Peoples R China Eye Dis Prevent Inst Harbin 150001 Heilongjiang Pr Peoples R China Heilongjiang Prov Hosp Dept Ophthalmol Harbin 150001 Heilongjiang Pr Peoples R China

AIM: To investigate the inhibitory effects of amniotic membrane, polylactic acid membrane and chitosan membrane on scar formation following trabeculectomy. METHODS: A total of 24 New Zealand white rabbits (48 eyes) were randomly divided into 4 groups: amniotic membrane group, polylactic acid membrane group, chitosan membrane group, and control group, with 6 rabbits (12 eyes) in each group. The left eyes underwent routine trabeculectomy, and the right eyes were considered as controls. Amniotic membrane, polylactic acid membrane and chitosan membrane were respectively installed under sclera flap in three groups, but any treatment was not applied in control group. Intraocular pressure, conjunctival filtering bleb, and anterior chamber inflammation responses were monitored at day 1, 3, 7, 14, 28 and 56 post-operatively. Eyeball tissue underwent histopathological examination at day 56 post-operatively. RESULTS: Fibrocytes and inflammatory cells were reduced in amniotic membrane, polylactic acid membrane and chitosan membrane groups compared to that in control group. At day 1 post-operatively, intraocular pressure was decreased in three membrane groups compared to that in control group. At day 14 post-operatively, the intraocular pressure was decreased significantly, while it of three membrane groups was significantly lower than that of preoperative (P0.05). Filtering bleb of four groups was clearly observed at day 7 post-operatively, but there was no significant difference in pair-wise comparison. At day 28 and 56 post-operatively, filtering bleb in control group was significantly narrowed compared to that in three membrane groups (P <0.05), but there was no significant difference in pair-wise comparison of three membrane groups. CONCLUSION: All amniotic membrane, polylactic acid membrane and chitosan membrane can effectively inhibit scar formation following trabeculectomy, the effect of amnioti

关键词： amniotic membrane polylactic acid membrane chitosan membrane glaucoma filtration surgery

Effects of Welding Speed and Post-weld Hot Rolling on Microstructure and Mechanical Properties of Friction Stir-Welded AZ31 Magnesium Alloy

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

Acta Metallurgica Sinica(English Letters) 2018年第8期31卷 853-864页

作者： Gang Liu Li-Na Ma Zhen-Duo Ma Xue-song fu Guo-Bing Wei Yan Yang Tian-Cai Xu Wei-Dong Xie Xiao-Dong Peng College of Materials Science and Engineering Chongqing UniversityChongqing 400044China National Engineering Research Center for Magnesium Alloys Chongqing 400044China

The as-rolled AZ31 Mg alloy sheets are welded by friction stir welding（FSW） in this study, followed by annealing and hot rolling with different reductions. The effects of welding speed and the rolling reduction on the microstructure, tensile properties, microhardness and fracture surfaces of the specimens are investigated. The results show that the microstructures of the FSW joint in different regions become more and more consistent as the hot rolling reduction increases. The mechanical properties of the FSW joints and the joint coefficient are improved with increasing rolling reduction; however,the hardness value in the stirred zone decreases firstly and then increases. When the rolling reduction is 50%, the tensile strength of FSW joint is close to that of base metal. The sample L_3 achieves the best comprehensive properties, with the yield strength, ultimate tensile strength and elongation of 162, 287.9 MPa, and 17.9%, respectively.

关键词： Magnesium alloy FSW Post-weld hot rolling Microstructure Mechanical properties