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“SUSPENDING VILLAGE”——A MODEL OF NEW DEVELOPED AREA IN NINGXIA OF CHINA
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作者 Wang Yiming Niu Huien Ningxia Regional Management Office, Yinchuan, Ningxia,750001 P. R. China Dept. of Town and Country Planning, Univ. of Newcastle uponTyne, Newcastle NE1 7RU, UK 《干旱区资源与环境》 CSCD 1993年第Z1期441-444,共4页
Ningxia is located in the Northwest China. The Huanghe (Yellow River) flowsthrough from its middle--west to the north. It is a province in which the Chinese Muslim--Hui Nationality is concentrated, with about one thir... Ningxia is located in the Northwest China. The Huanghe (Yellow River) flowsthrough from its middle--west to the north. It is a province in which the Chinese Muslim--Hui Nationality is concentrated, with about one third of the total population, hence theNingxia Hui Autonomous Region. From 1983 to 1992, more than 200000 people 展开更多
关键词 “suspending Village” POPULATION OVERLOAD PEOPLE MIGRATION Model
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Prevention of 25% Azoxystrobin Suspending Agent to Cucumber Downy Mildew
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作者 石凤梅 《Agricultural Science & Technology》 CAS 2014年第7期1178-1179,1228,共3页
[Objective] The aim was to research prevention effects of 25% azoxys trobin suspending agent to cucumber downy mildew.[Method] The test,including control group and four treatment groups with 450,600,and 750 g/hm2 25... [Objective] The aim was to research prevention effects of 25% azoxys trobin suspending agent to cucumber downy mildew.[Method] The test,including control group and four treatment groups with 450,600,and 750 g/hm2 25% azoxystrobin suspending agents,and 80% mancozeb wettable powder,was carried out in 2012 and 2013 consecutively to test the prevention effects of 25% azoxystrobin suspending agent to cucumber downy mildew.[Result] The prevention effects were significant of 25% azoxystrobin suspending agent to cucumber downy mildew in the range of 70.0%-83.6%,and it is recommended 25% azoxystrobin suspending agent at 600 g/hm2 be spread before plants diseased or in initial stage.In the whole stage,it was spread once every 7 d,totaling 3 times.[Conclusion] The research provides references for wide application of 25% azoxystrobin suspending agent in production. 展开更多
关键词 25% azoxystrobin suspending agent Cucumber downy mildew Prevention effects
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Production and Properties of a Thickener with Ability of Suspending Sand 被引量:4
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作者 QIN Bo-tao WANG De-ming LI Zeng-hua CHEN jian-hua 《Journal of China University of Mining and Technology》 EI 2006年第2期115-118,122,共5页
To overcome the shortcomings of pouring sands, a thickener with the ability to suspend sands was developed. It is mixed with sands to form densified slurry, and can insure the sands against deposition, jamming pipelin... To overcome the shortcomings of pouring sands, a thickener with the ability to suspend sands was developed. It is mixed with sands to form densified slurry, and can insure the sands against deposition, jamming pipelines and de- hydration. The chemical structure of the thickener is introduced in this paper and the production process is studied. The main processes include immersion, decomposition, dilution and addition of additives. In order to produce a thickener with high viscosity to suspend sands, key factors must be controlled in each process: the immersion time is 2 h; the mass fraction of formaldehyde is 0.01% and mass of NaCO3 accounts for 15% of dry material; the water temperature is 65 ℃ in summer and 72 ℃ in winter and the decomposition time is 2 h in the reaction; the densified decomposition so- lution should be diluted to 1% mass fraction; the additives of calcium ions and pH indicators must be added to the di- luted liquid; the mass fraction of CaCl2 is 0.048% and the pH value of the solution is 7.5. The thickener is a gel with three-dimensional network structure, a liquid with non-Newtonian behaviour and the characteristics of pseudo-plastic material, a solution with little resistance and the ability to revive its oral primary viscosity. It has been successfully ap- plied in Shendong Mines and has great value and wide-spread prospective use. 展开更多
关键词 THICKENER ability of suspending sand spontaneous combustion of coal
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Seismic Noise Suppression for Ground-Based Investigation of an Inertial Sensor by Suspending the Electrode Cage 被引量:6
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作者 谭定银 尹航 周泽兵 《Chinese Physics Letters》 SCIE CAS CSCD 2015年第9期9-12,共4页
Performance test of a high precise accelerometer or an inertial sensor on the ground is inevitably limited by the seismic noise. A torsion pendulum has been used to investigate the performances of an electrostatic acc... Performance test of a high precise accelerometer or an inertial sensor on the ground is inevitably limited by the seismic noise. A torsion pendulum has been used to investigate the performances of an electrostatic accelerometer, where the test mass is suspended by a fiber to compensate for its weight, and this scheme demonstrates an advantage, compared with the high-voltage levitation scheme, in which the effect of the seismic noise can be suppressed for a few orders of magnitude in low frequencies. In this work, the capacitive electrode cage is proposed to be suspended by another pendulum, and theoretical analysis shows that the effects of the seismic noise can be further suppressed for more than one order by suspending the electrode cage. 展开更多
关键词 LENGTH Seismic Noise Suppression for Ground-Based Investigation of an Inertial Sensor by suspending the Electrode Cage
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SUSPENDING VILLAGE" A MODEL OF NEW DEVELOPMENT AREA IN THE NINGXIA HUI AUTONOMOUS REGION OF CHINA
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作者 牛慧恩 汪一鸣 《Chinese Geographical Science》 SCIE CSCD 1993年第2期93-99,共7页
The southern part of the Ningxia Hui Autonomous Region in China was infamous for its poverty and serious soil erosion caused by over population. In order to alleviate poverty and backwardness, a plan was worked out: t... The southern part of the Ningxia Hui Autonomous Region in China was infamous for its poverty and serious soil erosion caused by over population. In order to alleviate poverty and backwardness, a plan was worked out: to remove 200,000 people to the north plain by developing newly irrigated land during the period of 1983-1992. The plan has been in operation for eight and half years to date. About 200,000 people have been removed from the poor southern part to the newly developed area, and 800,000 mu (1/ 15 ha) of desert land has been cultivated. Most of the migrants have been lifted out of poverty and the people’s life in the south is being improved. During the immigration process, a model, called 'Suspending Village', has been developed. In the article, the whole process of the development and the strategies are discussed. 展开更多
关键词 suspending VILLAGE REGIONAL DEVELOPMENT POPULATION RESETTLEMENT
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Electrically-driven ultrafast out-of-equilibrium light emission from hot electrons in suspended graphene/hBN heterostructures 被引量:1
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作者 Qiang Liu Wei Xu +7 位作者 Xiaoxi Li Tongyao Zhang Chengbing Qin Fang Luo Zhihong Zhu Shiqiao Qin Mengjian Zhu Kostya S Novoselov 《International Journal of Extreme Manufacturing》 SCIE EI CAS CSCD 2024年第1期328-338,共11页
Nanoscale light sources with high speed of electrical modulation and low energy consumption are key components for nanophotonics and optoelectronics.The record-high carrier mobility and ultrafast carrier dynamics of g... Nanoscale light sources with high speed of electrical modulation and low energy consumption are key components for nanophotonics and optoelectronics.The record-high carrier mobility and ultrafast carrier dynamics of graphene make it promising as an atomically thin light emitter which can be further integrated into arbitrary platforms by van der Waals forces.However,due to the zero bandgap,graphene is difficult to emit light through the interband recombination of carriers like conventional semiconductors.Here,we demonstrate ultrafast thermal light emitters based on suspended graphene/hexagonal boron nitride(Gr/hBN)heterostructures.Electrons in biased graphene are significantly heated up to 2800 K at modest electric fields,emitting bright photons from the near-infrared to the visible spectral range.By eliminating the heat dissipation channel of the substrate,the radiation efficiency of the suspended Gr/hBN device is about two orders of magnitude greater than that of graphene devices supported on SiO2or hBN.Wefurther demonstrate that hot electrons and low-energy acoustic phonons in graphene are weakly coupled to each other and are not in full thermal equilibrium.Direct cooling ofhigh-temperature hot electrons to low-temperature acoustic phonons is enabled by the significant near-field heat transfer at the highly localized Gr/hBN interface,resulting in ultrafast thermal emission with up to 1 GHz bandwidth under electrical excitation.It is found thatsuspending the Gr/hBN heterostructures on the SiO2trenches significantly modifies the light emission due to the formation of the optical cavity and showed a~440%enhancement inintensity at the peak wavelength of 940 nm compared to the black-body thermal radiation.The demonstration of electrically driven ultrafast light emission from suspended Gr/hBNheterostructures sheds the light on applications of graphene heterostructures in photonicintegrated circuits,such as broadband light sources and ultrafast thermo-optic phase modulators. 展开更多
关键词 suspended graphene ultrafast light emitter van der Waals heterostructures thermal radiation electron–phonon interaction
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Comprehensive Analysis of Suspending Force for Improved Bearingless Switched Reluctance Motor with Permanent Magnets in Stator Yoke
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作者 Fangxu Li Huijun Wang +1 位作者 Fengge Zhang He Zhang 《CES Transactions on Electrical Machines and Systems》 2018年第4期348-354,共7页
Different from conventional switched reluctance motor(SRM),bearingless SRM not only provides torque but also supplies levitation force for free-friction of rotor.In order to make sure that bearingless SRM can steadily... Different from conventional switched reluctance motor(SRM),bearingless SRM not only provides torque but also supplies levitation force for free-friction of rotor.In order to make sure that bearingless SRM can steadily levitates in static and dynamic rotating operation,it is necessary to analyze suspending force.Therefore,suspending force performance of an improved bearingless SRM with permanent magnets in stator yoke is comprehensively investigated in this paper.Basic structure and operation principle with permanent magnets in stator yoke are introduced firstly.Furthermore,mathematical model is built up for design of suspending force.In addition,parametric analysis for levitation performance is implemented.Finally,validity of proposed method is verified by experimental results. 展开更多
关键词 ANALYSIS BEARINGLESS switched reluctance suspending force
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When river meets ocean: distribution and conversion of suspended organic particles in a Sundarbans mangrove river-estuary system, Bangladesh
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作者 Xiaochun Zou Yunhai Li +8 位作者 Liang Wang Mohammad Kawser Ahmed Keliang Chen Jianwei Wu Yonghang Xu Yunpeng Lin Baohong Chen Kankan Wu Jinwen Liu 《Acta Oceanologica Sinica》 SCIE CAS CSCD 2024年第10期63-73,共11页
Global carbon cycle has received extensive attention,among which the river-estuary system is one of the important links connecting the carbon cycle between land and ocean.In this paper,the distribution and control fac... Global carbon cycle has received extensive attention,among which the river-estuary system is one of the important links connecting the carbon cycle between land and ocean.In this paper,the distribution and control factors of particulate organic carbon(POC)were studied by using the data of organic carbon contents and its carbon isotopic composition(δ13C)in the mainstream and estuary of Passur River in the Sundarbans area,combined with the hydrological and biological data measured by CTD.The results show that POC content ranged from 0.263 mg/L to 9.292 mg/L,and the POC content in the river section(averaged 4.129 mg/L)was significantly higher than that in the estuary area(averaged 0.858 mg/L).Two distinct stages of POC transport from land to sea in the Sundarbans area were identified.The first stage occurred in the river section,where POC distribution was mainly controlled by the dynamic process of runoff and the organic carbon was mainly terrestrial source.The second stage occurred during estuarine mixing,where the POC distribution was mainly controlled by the mixing process of seawater and freshwater.The source of POC was predominantly marine and exhibiting vertical differences.The surface and middle layers were primarily influenced by marine sources,while the bottom layer was jointly controlled by terrestrial and marine sources of organic carbon.These findings are of great significance for understanding the carbon cycle in such a large mangrove ecosystem like the Sundarbans mangrove. 展开更多
关键词 suspended particles particle organic carbon Sundarbans mangrove river-estuary system
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Synthesis of Acrylic Acid/Kaoline Powder Superabsorbent Composite by Inverse-suspending Polymerization
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作者 ZHONGJin-feng XUEYi-ming WUJi-huai LINJian-ming WEIYue-lin 《Chemical Research in Chinese Universities》 SCIE CAS CSCD 2004年第3期362-365,共4页
An acrylic acid/kaoline powder superabsorbent composite with a water absorbency of the superabsorbent composite about 1/800 was synthesized by inverse\|suspending polymerization reaction between acrylic acid monomer a... An acrylic acid/kaoline powder superabsorbent composite with a water absorbency of the superabsorbent composite about 1/800 was synthesized by inverse\|suspending polymerization reaction between acrylic acid monomer and kaoline ultrafine powder. The influence of the dispersant agent on the configuration of the products in the inverse suspension polymerization is investigated. The influences of the kaoline powder,cross\|linker,initiator,neutralization degree and the volume ratio of oil to water phase on the water absorbency of the superabsorbent composites are discussed in the paper. 展开更多
关键词 Superabsorbent composite Inverse-suspending polymerization Acrylic acid Kaoline powder
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Using Natural Radionuclides to Trace Sources of Suspended Particles in the Lower Reaches of the Yellow River
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作者 ZHANG Han BURNETT CWilliam +5 位作者 ZHANG Xiaojie ZHAO Shibin YANG Disong NAN Haiming YU Zhigang XU Bochao 《Journal of Ocean University of China》 CAS CSCD 2024年第1期99-108,共10页
Natural radionuclides are powerful tools for understanding the sources and fate of suspended particulate matter(SPM).Particulate matter with different particle sizes behaves differently with respect to adsorption and ... Natural radionuclides are powerful tools for understanding the sources and fate of suspended particulate matter(SPM).Particulate matter with different particle sizes behaves differently with respect to adsorption and desorption.We analyzed the activi-ties and distribution characteristics of multiple natural radionuclides(238U,226Ra,40K,228Ra,7Be and 210Pbex)on size-fractionated SPM at the Lijin Hydrographic Station(Huanghe or Yellow River)every month over a one-year period.Results showed that medium silt(16–32µm)was the main component.As expected,the activity of each radionuclide decreased with an increase of particle size.We examined the sources of SPM with different particle sizes using activity ratios of 226Ra/238U,228Ra/226Ra,40K/238U and 7Be/210Pbex,and concluded that SPM with different particle sizes originated from different sources.Our results indicate that fine SPM(<32µm)was mainly from the erosion of soil along the lower reaches of the Yellow River,while coarse SPM(>32µm)was mainly derived from resuspension of riverbed sediment.During high runoff periods,the concentration of SPM increased significantly,and the pro-portion of fine particles originating upstream increased.Naturally occurring radioactive isotopes,especially on size-fractionated par-ticles,are therefore seen as useful tracers to understand the sources and behaviors of riverine particles transported from land to sea. 展开更多
关键词 the Yellow River suspended particulate matter size-fractions radionuclides sediment sources water elutriator
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三峡水库微塑料与悬沙的聚集特性及作用机制
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作者 刘洁 张智超 +2 位作者 李霞 朱丽帆 蒋晖 《湖泊科学》 EI CAS 北大核心 2025年第1期149-158,共10页
本文依据三峡库区悬沙矿物组成和泥沙级配为依据配置沙样,选择长江上游典型微塑料PMMA和PS,在自制大型水箱中开展水流剪切作用下微塑料和泥沙异质聚集实验,分析微泥絮团的形态特征和聚集机制。结果表明在水流紊动剪切作用下,相比泥沙同... 本文依据三峡库区悬沙矿物组成和泥沙级配为依据配置沙样,选择长江上游典型微塑料PMMA和PS,在自制大型水箱中开展水流剪切作用下微塑料和泥沙异质聚集实验,分析微泥絮团的形态特征和聚集机制。结果表明在水流紊动剪切作用下,相比泥沙同质聚集的絮团粒径,微泥异质聚集的絮团粒径更大,且每毫升样品中微泥絮团上的微塑料吸附数量随水流剪切率增大而迅速增加。扫描电镜和能谱分析结果表明,在水动力条件下泥沙与PMMA、PS微球发生异质聚集,聚集过程中存在电子转移和化学态的转变,并产生不饱和键(C C)。由于PMMA官能团的结合能变化比PS大,此过程失电子更多、表面电荷更大,更容易与泥沙发生聚集。 展开更多
关键词 微塑料 悬沙 微泥絮团形貌 聚集机制 三峡水库
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Coastal Current Systems and the Movement and Expansion of Suspended Sediment from Changjiang River Estuary 被引量:5
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作者 李四海 恽才兴 《Marine Science Bulletin》 CAS 2006年第1期22-33,共12页
This paper, with NOAA/AHHRR data for 2 years, discusses the expanding path and extent of suspended sediment from the Changjiang River, and the relationship between the suspended sediment expanding and coastal current ... This paper, with NOAA/AHHRR data for 2 years, discusses the expanding path and extent of suspended sediment from the Changjiang River, and the relationship between the suspended sediment expanding and coastal current systems by analyzing the thermal infrared imagery with the sediment imagery, which is acquired by correlating the atmosphere corrected AVHRR imagery with in-situ suspended sediment data. The coastal current systems affecting the sediment dispersal mainly include: the Taiwan Warm Current (TWC), the Huanghai Sea Mixed Water (HSMW), North Jiangsu near-shore current, and Zhejiang near-shore current etc. In winter, the current systems are stable. Their distribution affects the sediment from north Jiangsu expanding toward the Changjiang estuary in some degree .The front between Zhejiang coastal current and TWC blocks the expanding of sediment toward the sea. In the flood season, apart from the limitation by coastal current systems, the spatial and temporal distribution of suspended sediment is also affected by the runoff, which shows as the jet stream and fresh water. Spring and autumn are the transitional periods of the forming of expanding patterns of flood season and winter respectively. In addition, the re-suspended sediment caused by the wind wave may make the expanding range of near-shore sediment larger. 展开更多
关键词 NOAA/AVHRR Changjiang estuary suspended sediment coastal current systems
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1984—2021年黄河口及邻近海域悬浮物锋面变化特征及影响因素研究
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作者 郝祚千 陈民强 +5 位作者 赵盖博 任兆鹏 江文胜 王涛 胡连波 边昌伟 《中国海洋大学学报(自然科学版)》 CAS 北大核心 2025年第1期25-38,共14页
本研究利用Landsat卫星遥感数据提取了1984—2021年黄河口及其邻近海域的悬浮物锋面(Suspended sediment fronts,SSF),并分析了SSF位置的季节和年代际变化特征。结果表明,SSF的位置存在显著的季节变化,冬季距河口最远而夏季距河口最近,... 本研究利用Landsat卫星遥感数据提取了1984—2021年黄河口及其邻近海域的悬浮物锋面(Suspended sediment fronts,SSF),并分析了SSF位置的季节和年代际变化特征。结果表明,SSF的位置存在显著的季节变化,冬季距河口最远而夏季距河口最近,平均距离分别为45.6与24.2 km。通过黄河口海域表层悬浮物浓度的年代际变化推测SSF在1984—2021年向河口方向收缩了大约25.6%。黄河口附近气象站的风速分析结果表明,风速在近40年的减小是SSF向河口收缩的主要原因;黄河入海水沙虽然也存在显著下降的趋势,但对黄河口SSF年代际变化的直接影响很小。 展开更多
关键词 悬浮物锋面 Landsat卫星 黄河口 年代际变化 悬浮物浓度
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Characteristics of suspended planar-type gas sensor based on MEMS process 被引量:1
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作者 张子立 殷晨波 +1 位作者 陶春旻 朱斌 《Journal of Southeast University(English Edition)》 EI CAS 2012年第3期315-320,共6页
In order to simplify the fabrication process,distribute the temperature uniformly and reduce the power consumption of the micro-hotplate(MHP) gas sensor,a planar-type gas sensor based on SnO2 thin film with suspende... In order to simplify the fabrication process,distribute the temperature uniformly and reduce the power consumption of the micro-hotplate(MHP) gas sensor,a planar-type gas sensor based on SnO2 thin film with suspended structure is designed through a MEMS process.Steady-state thermal analysis of the gas sensor and the closed membrane type sensor where the membrane overlaps the Si substrate is carried out with the finite element model,and it is shown that the suspended planar-type gas sensor has a more homogeneous temperature distribution and a lower power consumption.When the maximum temperature on the sensor reaches 383℃,the power consumption is only 7 mW,and the temperature gradient across the thin film is less than 14℃.To overcome the fragility of the suspended beams,a novel fabrication process in which the deposition of the gas sensing film occurs prior to the formation of suspended beams is proposed.The back side of the Si substrate is etched through deep reactive ion etching(DRIE) to avoid chemical pollution of the front side.The fabrication steps in which only four masks are used for the photolithography are described in detail.The Fe doped SnO2 thin film synthesized by sol-gel spin-coating is used as the gas sensing element.The device is tested on hydrogen and exhibits satisfactory sensing performance.The sensitivity increases with the rise of the concentration from 50×10-6 to 2000×10-6,and reaches about 30 at 2000×10-6. 展开更多
关键词 gas sensor suspended planar-type micro fabrication gas sensing characteristic
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A New Method for Calculation of Natural Frequency of Suspended Pipeline 被引量:1
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作者 鲁晓光 唐友刚 郑治国 《Transactions of Tianjin University》 EI CAS 2002年第4期282-284,共3页
The buried pipelines are widely used in oil transportation. The pipelines become suspended in the river with flushing of floodwater. If the frequency of vortex shedding is near to the nature frequency of pipelines, it... The buried pipelines are widely used in oil transportation. The pipelines become suspended in the river with flushing of floodwater. If the frequency of vortex shedding is near to the nature frequency of pipelines, it will cause resonance of the suspended pipeline and result in the damage of pipelines. In this paper, the buried parts of pipeline in soil are treated as the half unlimited long beam placed on the elastic foundations. The vibration partial differential equations of suspended pipe and the parts buried in soil are derived respectively. The iterative calculation method is then presented. The results obtained from the suggested method are proved to be identical with the measured values. 展开更多
关键词 suspended pipeline half unlimited long beam natural frequency
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Dynamic response analysis of the submarine suspended pipeline impacted by dropped objects based on LS-DYNA 被引量:4
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作者 娄敏 明海芹 《Marine Science Bulletin》 CAS 2015年第2期39-55,共17页
Based on ANSYS/LS-DYNA, the dynamics analysis software, and using nonlinear dynamic finite element method, the process of a submarine pipeline impacted by dropped objects is simulated, Some conclusions are drawn: Fir... Based on ANSYS/LS-DYNA, the dynamics analysis software, and using nonlinear dynamic finite element method, the process of a submarine pipeline impacted by dropped objects is simulated, Some conclusions are drawn: First, the damage depth of suspended pipe is smaller than that of the bare pipe in case of the same fall energy, and with the increase of fall energy, the difference grows; Second, with the falling object's speed and mass rising, the deformation of pipeline intensifies at the impact site and the maximum vibration amplitude of submarine pipeline increases; Third, when the fall energy is equal, the smaller the contact area of falling objects and pipeline is, the greater the damage depth of pipeline becomes; Fourth, changes of seabed soil parameters (shear elastic modulus, internal friction angle, density) have less influence on the suspended pipeline's dent depths and maximum vibration amplitude, 展开更多
关键词 suspended pipeline IMPACT dent depths dynamic response
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Variations in tidal currents and suspended sediment concentration of the upper part of the North Channel of Changjiang Estuary over the past 10 years 被引量:1
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作者 刘高伟 程和琴 +3 位作者 计娜 乔远英 胡浩 王冬梅 《Marine Science Bulletin》 CAS 2015年第2期9-24,共16页
The tidal current duration (TCD) and velocity (TCV) and suspended sediment concentration (SSC) were measured in the dry season in December, 2011 and in the flood season in June, 2012 at the upper part of the Nor... The tidal current duration (TCD) and velocity (TCV) and suspended sediment concentration (SSC) were measured in the dry season in December, 2011 and in the flood season in June, 2012 at the upper part of the North Channel of Changjiang Estuary. They were assimilated with the measured data in 2003, 2004, 2006 and 2007, using the tidal range's proportion conversion. Variations in TCD and TCV, preferential flow and SSC have been calculated. Influences of typical engineering projects such as Qingcaosha fresh water reservoir, Yangtze River Bridge, and land reclamation on the ebb and flood TCD, TCV and SSC in the North Channel for the last 10 years are discussed. The results show that: (1) currently, in the upper part of North Channel, the ebb tide dominates; after the construction of the typical projects, ebb TCD and TCV tends to be larger and the vertical average ebb and flood SSC decrease during the flood season while SSC increases during the dry season; (2) changes in the vertical average TCV are mainly contributed by seasonal runoff variation during the flood season, which is larger in the flood season than that in the dry season; the controlling parameters of increasing ebb TCD and TCV are those large-scale engineering projects in the North Channel; variation in SSC may result mainly from the reduction of basin annual sediment loads, large-scale nearshore projects and so on. 展开更多
关键词 changes in tidal currents and suspended sediment concentration preferential flow data assimilation large-scale engineering projects Changjiang Estuary
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颗粒物沉降影响下草/藻型湖区沉积物-水界面氮交换特征及机制
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作者 韩汶轩 陈秋羽 +3 位作者 何煦 谭立贤 刘成 张雷 《湖泊科学》 EI CAS 北大核心 2025年第1期76-88,共13页
富营养化湖泊水体中颗粒物的不断富集和沉降加剧了沉积物内源负荷。本文以太湖典型草、藻型湖区为研究对象,开展了为期一年的野外月度调查,分析了两种湖区水样、颗粒物和沉积物中各形态氮含量、赋存形式及其沉积物水界面交换特征,研究... 富营养化湖泊水体中颗粒物的不断富集和沉降加剧了沉积物内源负荷。本文以太湖典型草、藻型湖区为研究对象,开展了为期一年的野外月度调查,分析了两种湖区水样、颗粒物和沉积物中各形态氮含量、赋存形式及其沉积物水界面交换特征,研究了颗粒物沉降对草、藻型湖区沉积物水界面氮赋存形态转变及迁移的影响。结果表明,草、藻型湖区水体总氮(TN)浓度年变化范围分别为0.50~1.51 mg/L(均值为(0.97±0.23)mg/L)和1.77~6.12 mg/L(均值为(3.67±1.36)mg/L),藻型湖区水体各形态氮浓度普遍高于草型湖区,且季节性变化更加显著。草、藻型湖区悬浮颗粒物中TN含量年均值分别为(6998.48±1413.87)和(5162.63±2205.13)mg/kg,沉积物TN平均含量分别为(4219.75±216.62)和(3187.88±103.07)mg/kg,呈现草型湖区显著高于藻型湖区、悬浮颗粒物显著高于沉积物的特征。氨氮(NH 3-N)是两个湖区悬浮颗粒物和沉积物中有效态氮的主要赋存形式,藻型湖区沉积物中NH 3-N的释放主要集中在夏季,而草型湖区则以夏、秋季为主。有效态氮高度富集的颗粒物不断沉降是造成沉积物中氮含量改变的重要原因,且藻型湖区有效态氮所占比例(5.17%)在藻类水华季节高于草型湖区(4.34%)。草型系统向藻型系统的转变可能会升高水体颗粒物浓度并加剧沉积物颗粒再悬浮过程,颗粒物沉降和再悬浮交替加剧了沉积物水界面处氮的交换过程,在未来的湖泊内源氮管理中应更加重视颗粒物的作用。 展开更多
关键词 太湖 草型湖区 藻型湖区 悬浮颗粒物 内源氮负荷
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MEMS Inductor Consisting of Suspended Thick Crystalline Silicon Spiral with Copper Surface Coating
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作者 吴文刚 李轶 +4 位作者 黄风义 韩翔 张少勇 李志宏 郝一龙 《Journal of Semiconductors》 EI CAS CSCD 北大核心 2006年第4期662-666,共5页
A novel MEMS inductor consisting of a planar single crystalline silicon spiral with a copper surface coating as the conductor is presented. Using a silicon-glass anodic bonding and deep etching formation-and-release p... A novel MEMS inductor consisting of a planar single crystalline silicon spiral with a copper surface coating as the conductor is presented. Using a silicon-glass anodic bonding and deep etching formation-and-release process,a 40μm-thick silicon spiral is formed, which is suspended on a glass substrate to eliminate substrate loss. The surfaces of the silicon spiral are coated with highly conformal copper by electroless plating to reduce the resis- tive loss in the conductor,with thin nickel film plated on the surface of the copper layer for final surface passivation. The fabricated inductor exhibits a self-resonance frequency higher than 15GHz,with a quality factor of about 40 and an inductance of over 5nil at 11.3GHz. Simulations based on a compact equivalent circuit model of the inductor and parameter extraction using a characteristic-function approach are carried out,and good agreement with measurements is obtained. 展开更多
关键词 MEMS inductor suspended spiral copper coating quality factor modeling and parameter extrac tion radio frequency
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非结构构件抗震韧性技术研究综述
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作者 刘福禄 辛力 +2 位作者 岳焱超 陈杰 张宇航 《山西建筑》 2025年第4期54-58,共5页
建筑非结构构件的抗震破坏程度较大,损失较为严重,但是其投资占比大、功能性强,因此越来越受到相关学者和工程师的重视,文章论述了非结构构件的抗震韧性技术研究进展,介绍了抗震韧性理念与非结构构件的分类,分析了建筑工程常见的非结构... 建筑非结构构件的抗震破坏程度较大,损失较为严重,但是其投资占比大、功能性强,因此越来越受到相关学者和工程师的重视,文章论述了非结构构件的抗震韧性技术研究进展,介绍了抗震韧性理念与非结构构件的分类,分析了建筑工程常见的非结构构件的震害表现与研究现状。结合实际工程经验,总结了国内现行规范中设计及施工方法和合理处理建议,希望能为非结构构件抗震韧性技术的后续发展提供参考。 展开更多
关键词 非结构构件 填充墙 吊顶 抗震支吊架
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