期刊文献+
共找到28篇文章
< 1 2 >
每页显示 20 50 100
基于Revised IMPROVE方法和MIE方法计算北京地区气溶胶消光系数的对比分析 被引量:3
1
作者 刘斌 臧增亮 +3 位作者 田平 颜鹏 蔡恒明 张仁健 《装备环境工程》 CAS 2019年第6期123-128,共6页
目的对比分析IMPROVE方程的改进算法(Revised IMPROVE)和MIE方法在北京地区计算消光系数的适用性。方法基于2012年6月3日至6月30日北京地区大气颗粒物成分的浓度观测数据,分别采用Revised IMPROVE和MIE方法计算颗粒物的消光系数,其中MI... 目的对比分析IMPROVE方程的改进算法(Revised IMPROVE)和MIE方法在北京地区计算消光系数的适用性。方法基于2012年6月3日至6月30日北京地区大气颗粒物成分的浓度观测数据,分别采用Revised IMPROVE和MIE方法计算颗粒物的消光系数,其中MIE方法的粒径分布采用总量双峰分布体积谱和化学组分体积谱两种方案进行循环试验获取最优拟合结果,使用散射积分浊度计和黑碳仪的实测数据对计算结果进行对比分析。结果Revised IMPROVE方程、总量双峰体积谱MIE方法和化学组分体积谱MIE方法都能较好地计算出了大气颗粒物消光系数,与观测结果回归方程的相关系数R分别达到0.952、0.9686和0.9734。体积谱分布参数的循环试验方法还同时可以获得气溶胶的体积谱分布参数,总量双峰体积谱和化学组分体积谱MIE方法得到的细颗粒和粗颗粒几何平均粒径分别为0.74、7.5μm和0.48、6.0μm。结论采用化学组分体积谱MIE方法计算的消光系数与观测结果最为接近,Revised IMPROVE方程也有较好的准确性,采用化学组分体积谱MIE方法得到的颗粒物体积谱峰值与实际观测结果也较为一致。 展开更多
关键词 消光系数 revised IMPROVE MIE方法
在线阅读 下载PDF
Characteristics of canopy interception and its simulation with a revised Gash model for a larch plantation in the Liupan Mountains, China 被引量:2
2
作者 Zebin Liu Yanhui Wang +7 位作者 Ao Tian Yu Liu Ashley A.Webb Yarui Wang Haijun Zuo Pengtao Yu Wei Xiong Lihong Xu 《Journal of Forestry Research》 SCIE CAS CSCD 2018年第1期187-198,共12页
Canopy interception is a significant proportion of incident rainfall and evapotranspiration of forest ecosystems. Hence, identifying its magnitude is vital for studies of eco-hydrological processes and hydrological im... Canopy interception is a significant proportion of incident rainfall and evapotranspiration of forest ecosystems. Hence, identifying its magnitude is vital for studies of eco-hydrological processes and hydrological impact evaluation. In this study, throughfall, stemflow and interception were measured in a pure Larix principis-rupprechtii Mayr.(larch) plantation in the Liupan Mountains of northwestern China during the growing season(May–October) of 2015, and simulated using a revised Gash model. During the study period, the total precipitation was 499.0 mm; corresponding total throughfall, stemflow and canopy interception were 410.3, 2.0 and 86.7 mm,accounting for 82.2, 0.4 and 17.4% of the total precipitation, respectively. With increasing rainfall, the canopy interception ratio of individual rainfall events decreased initially and then tended to stabilize. Within the study period, the simulated total canopy interception, throughfall and stemflow were 2.2 mm lower, 2.5 mm higher and 0.3 mm lower than their measured values, with a relative error of 2.5, 0.6 and 15.0%, respectively. As quantified by the model, canopy interception loss(79%) mainly consisted of interception caused by canopy adsorption, while the proportions of additional interception and trunk interception were small. The revised Gash model was highly sensitive to the parameter of canopy storage capacity,followed by the parameters of canopy density and mean rainfall intensity, but less sensitive to the parameters of mean evaporation rate, trunk storage capacity, and stemflow ratio. The revised Gash model satisfactorily simulated the total canopy interception of the larch plantation within the growing season but was less accurate for some individual rainfall events, indicating that some flaws exist in the model structure. Further measures to improve the model’s ability in simulating the interception of individual rainfall events were suggested. 展开更多
关键词 Canopy interception Larch plantation revised Gash model STEMFLOW THROUGHFALL
在线阅读 下载PDF
A revised jump-diffusion and rotation-diffusion model
3
作者 Hua Li Yu-Hang Chen Bin-Ze Tang 《Chinese Physics B》 SCIE EI CAS CSCD 2019年第5期216-221,共6页
Quasi-elastic neutron scattering(QENS) has many applications that are directly related to the development of highperformance functional materials and biological macromolecules, especially those containing some water. ... Quasi-elastic neutron scattering(QENS) has many applications that are directly related to the development of highperformance functional materials and biological macromolecules, especially those containing some water. The analysis method of QENS spectra data is important to obtain parameters that can explain the structure of materials and the dynamics of water. In this paper, we present a revised jump-diffusion and rotation-diffusion model(rJRM) used for QENS spectra data analysis. By the rJRM, the QENS spectra from a pure magnesium-silicate-hydrate(MSH) sample are fitted well for the Q range from 0.3 ^(-1) to 1.9 ^(-1) and temperatures from 210 K up to 280 K. The fitted parameters can be divided into two kinds. The first kind describes the structure of the MSH sample, including the ratio of immobile water(or bound water) C and the confining radius of mobile water a_0. The second kind describes the dynamics of confined water in pores contained in the MSH sample, including the translational diffusion coefficient Dt, the average translational residence timeτ0, the rotational diffusion coefficient D_r, and the mean squared displacement(MSD) u^2. The r JRM is a new practical method suitable to fit QENS spectra from porous materials, where hydrogen atoms appear in both solid and liquid phases. 展开更多
关键词 revised JUMP-DIFFUSION and rotation-diffusion model (rJRM) data analysis of quasi-elastic neutron scattering (QENS) spectra dynamics of water magnesium-silicate-hydrate (MSH) samples
在线阅读 下载PDF
《空气动力学学报》2012年第30卷第3期有6篇论文英文摘要用了Ei Thesaurus,Revised第6版主题词
4
作者 胡沛泉 《西北工业大学学报》 EI CAS CSCD 北大核心 2012年第4期496-496,共1页
关键词 英文摘要 主题词 叙词 检索词 Ei Thesaurus revised
在线阅读 下载PDF
Total cross sections for electron scattering from fluoromethanes:A revised additivity rule method
5
作者 谭晓明 赵刚 《Chinese Physics B》 SCIE EI CAS CSCD 2012年第6期167-171,共5页
The additivity rule for electron-molecule scattering is revised by considering the difference between the free atom and the bound atom in the molecule. The total cross sections for electron scattering from fluorometha... The additivity rule for electron-molecule scattering is revised by considering the difference between the free atom and the bound atom in the molecule. The total cross sections for electron scattering from fluoromethanes (CF4, CF3H, CF2H2, and CFH3) are calculated in an energy range from 100 eV to 1500 eV by the revised additivity rule. The present calculations are compared with the original additivity rule results and the available experimental data. Better agreement with each other is obtained. 展开更多
关键词 total cross section electron scattering revised additivity rule
在线阅读 下载PDF
THE LOW MACH NUMBER LIMIT FOR ISENTROPIC COMPRESSIBLE NAVIER-STOKES EQUATIONS WITH A REVISED MAXWELL'S LAW
6
作者 胡玉玺 王召 《Acta Mathematica Scientia》 SCIE CSCD 2023年第3期1239-1250,共12页
We investigate the low Mach number limit for the isentropic compressible NavierStokes equations with a revised Maxwell's law(with Galilean invariance) in R^(3). By applying the uniform estimates of the error syste... We investigate the low Mach number limit for the isentropic compressible NavierStokes equations with a revised Maxwell's law(with Galilean invariance) in R^(3). By applying the uniform estimates of the error system, it is proven that the solutions of the isentropic Navier-Stokes equations with a revised Maxwell's law converge to that of the incompressible Navier-Stokes equations as the Mach number tends to zero. Moreover, the convergence rates are also obtained. 展开更多
关键词 isentropic compressible Navier-Stokes equations low Mach number limit revised Maxwell's law
在线阅读 下载PDF
The Revised Realization of Sapir:Whorf Hypothesis
7
作者 孙啸 《海外英语》 2010年第6X期249-249,共1页
There are a lot of arguments on Sapir-Whorf hypothesis in linguistics field,most of the scholars have given their own understandings toward this theory.It is easier to comment on a theory no matter what kind of theory... There are a lot of arguments on Sapir-Whorf hypothesis in linguistics field,most of the scholars have given their own understandings toward this theory.It is easier to comment on a theory no matter what kind of theory it is,however,different views do not come from the same theory but different understandings of it,so writer think it is necessary to give a revised realization to the theory. 展开更多
关键词 Sapir-Whorf HYPOTHESIS revised REALIZATION the RELATIONSHIP BETWEEN LANGUAGE and MIND
在线阅读 下载PDF
China Revises Its Oil Resources Rules for Foreign Cooperation
8
《China Oil & Gas》 CAS 2001年第4期37-,共1页
关键词 China revises Its Oil Resources Rules for Foreign Cooperation
在线阅读 下载PDF
The Extended Hybrid Carrier-Based Multiple Access Technology for High Mobility Scenarios 被引量:1
9
作者 Ge Song Xiaojie Fang Xuejun Sha 《China Communications》 SCIE CSCD 2024年第1期53-68,共16页
The hybrid carrier(HC)system rooted in the carrier fusion concept is gradually garnering attention.In this paper,we study the extended hybrid carrier(EHC)multiple access scheme to ensure reliable wireless communicatio... The hybrid carrier(HC)system rooted in the carrier fusion concept is gradually garnering attention.In this paper,we study the extended hybrid carrier(EHC)multiple access scheme to ensure reliable wireless communication.By employing the EHC modulation,a power layered multiplexing framework is realized,which exhibits enhanced interference suppression capability owing to the more uniform energy distribution design.The implementation method and advantage mechanism are explicated respectively for the uplink and downlink,and the performance analysis under varying channel conditions is provided.In addition,considering the connectivity demand,we explore the non-orthogonal multiple access(NOMA)method of the EHC system and develop the EHC sparse code multiple access scheme.The proposed scheme melds the energy spread superiority of EHC with the access capacity of NOMA,facilitating superior support for massive connectivity in high mobility environments.Simulation results have verified the feasibility and advantages of the proposed scheme.Compared with existing HC multiple access schemes,the proposed scheme exhibits robust bit error rate performance and can better guarantee multiple access performance in complex scenarios of nextgeneration communications. 展开更多
关键词 extended hybrid carrier system high mo-Received:Jun.09 2023 revised:Nov.20 2023 Editor:Yuanwei Liu bility communications multiple access
在线阅读 下载PDF
Addressing soil protection concerns in forest ecosystem management under climate change 被引量:4
10
作者 Ana Raquel Rodrigues Brigite Botequim +2 位作者 Catarina Tavares Patrícia Pécurto JoséGBorges 《Forest Ecosystems》 SCIE CSCD 2020年第3期432-442,共11页
Background: Climate change may strongly influence soil erosion risk, namely through variations in the precipitation pattern. Forests may contribute to mitigate the impacts of climate change on soil erosion and forest ... Background: Climate change may strongly influence soil erosion risk, namely through variations in the precipitation pattern. Forests may contribute to mitigate the impacts of climate change on soil erosion and forest managers are thus challenged by the need to define strategies that may protect the soil while addressing the demand for other ecosystem services. Our emphasis is on the development of an approach to assess the impact of silvicultural practices and forest management models on soil erosion risks under climate change. Specifically, we consider the annual variation of the cover-management factor(C) in the Revised Universal Soil Loss Equation over a range of alternative forest management models to estimate the corresponding annual soil losses, under both current and changing climate conditions. We report and discuss results of an application of this approach to a forest area in Northwestern Portugal where erosion control is the most relevant water-related ecosystem service.Results: Local climate change scenarios will contribute to water erosion processes, mostly by rainfall erosivity increase.Different forest management models provide varying levels of soil protection by trees, resulting in distinct soil loss potential.Conclusions: Results confirm the suitability of the proposed approach to address soil erosion concerns in forest management planning. This approach may help foresters assess management models and the corresponding silvicultural practices according to the water-related services they provide. 展开更多
关键词 C-FACTOR EROSIVITY Ecosystem services Forest management revised universal soil loss equation(RUSLE)
在线阅读 下载PDF
基于RUSLE模型的河南省黄河流域土壤侵蚀研究 被引量:9
11
作者 刘天可 袁彩凤 《华北水利水电大学学报(自然科学版)》 2020年第3期7-13,共7页
为了更好地研究黄河河南段的土壤侵蚀情况,以河南省黄河流域为研究区域,采用地理信息系统和遥感技术,融合遥感影像、DEM数据、降雨数据和土壤数据等,将RUSLE模型应用到该区域的土壤侵蚀研究中。结果表明:该区域的年均土壤侵蚀模数为861.... 为了更好地研究黄河河南段的土壤侵蚀情况,以河南省黄河流域为研究区域,采用地理信息系统和遥感技术,融合遥感影像、DEM数据、降雨数据和土壤数据等,将RUSLE模型应用到该区域的土壤侵蚀研究中。结果表明:该区域的年均土壤侵蚀模数为861.78 t/(km^2·a),年均土壤侵蚀总量为305.44×10^5 t/a,轻度以上的土壤侵蚀多发生在河南西部的一些省辖市内。其中,土壤侵蚀等级为轻度以下的区域,其面积占研究区总面积的88.39%,该区域主要分布在0°~10°坡度范围内,主要的土地利用类型为耕地和草地;中度侵蚀和强烈侵蚀的区域,二者的总面积占比为10.71%,主要分布在15°~25°坡度范围内,土地利用类型主要为林地;极强烈侵蚀和剧烈侵蚀的区域面积所占比例较小,占比共计0.9%,该区域零星分布在坡度范围大于25°的草地和林地区域。该研究成果揭示了河南省黄河流域的土壤侵蚀情况,可为区域水土流失治理提供科学依据。 展开更多
关键词 河南省黄河流域 RUSLE(revised Universal Soil Loss Equation) 土壤侵蚀 水土流失
在线阅读 下载PDF
Guarding Legal Communication with Smart Jammer:Stackelberg Game Based Power Control Analysis 被引量:4
12
作者 Zhe Su Nan Qi +4 位作者 Yongjie Yan Zhiyong Du Jiaxin Chen Zhibin Feng Qihui Wu 《China Communications》 SCIE CSCD 2021年第4期126-136,共11页
This paper investigates a power control problem in a jamming system,where a separate smart jammer is deployed to ensure the communication security of the legal user.However,due to power leakage,the smart jammer may in... This paper investigates a power control problem in a jamming system,where a separate smart jammer is deployed to ensure the communication security of the legal user.However,due to power leakage,the smart jammer may incur unintentional interference to legal users.The key is how to suppress illegal communication while limit the negative impact on legal user.A jamming counter measure Stackelberg game is formulated to model the jamming power control dynamic of the system.The smart jammer acts as a leader to sense and interfere illegal communications of the illegal user,while the illegal user acts as a follower.In the game,the impact of uncertain channel information is taken into account.According to whether illegal user considers the uncertain channel information,we investigate two scenarios,namely,illegal user can obtain statistical distribution and accurate information of interference channel gain and its own cost,respectively.This work not only proposes a jamming counter measure iterative algorithm to update parameters,but also gives two solutions to obtain the Stackelberg equilibrium(SE).The power convergence behaviours under two scenarios are analyzed and compared.Additionally,brute force is used to verify the accuracy of the SE value further. 展开更多
关键词 power control jamming communication Received:Apr.13 2020 revised:Sep.01 2020 Editor:Haifeng Zheng systems Stackelberg game
在线阅读 下载PDF
Comment on "Improvement of Controlled Bidirectional Quantum Direct Communication Using a GHZ State" [Chin. Phys. Lett. 30 (2013) 040305] 被引量:1
13
作者 LIU Zhi-Hao CHEN Han-Wu 《Chinese Physics Letters》 SCIE CAS CSCD 2013年第7期258-258,共1页
The problem of definite information leakage existing in the controlled bidirectional quantum direct communication protocol using GHZ states[Chin.Phys.Lett.23(2006)1680]was pointed out by Ye and Jiang[Chin.Phys.Lett.30... The problem of definite information leakage existing in the controlled bidirectional quantum direct communication protocol using GHZ states[Chin.Phys.Lett.23(2006)1680]was pointed out by Ye and Jiang[Chin.Phys.Lett.30(2013)040305].Then,they proposed two strategies to improve this security bug.However,if the revised versions are analyzed from the viewpoint of information theory,it can be found that they still have the problem of information leakage.That is,three quarters and one half of the information interchanged by the communication parties are leaked out unknowingly in the first and second revised protocols,respectively. 展开更多
关键词 revised definite VIEWPOINT
在线阅读 下载PDF
Barriers to WHO Mental Health Action Plan updates to expand family and caregiver involvement in mental healthcare 被引量:1
14
作者 Jens Peter Eckardt 《General Psychiatry》 CAS CSCD 2022年第2期154-156,共3页
In 2021,the 74th World Health Assembly endorsed updates to the WHO's Comprehensive Mental Health Action Plan extending to 2030,including revised indicators to measure progress towards reaching defined targets and ... In 2021,the 74th World Health Assembly endorsed updates to the WHO's Comprehensive Mental Health Action Plan extending to 2030,including revised indicators to measure progress towards reaching defined targets and expanded implementation options for variousfacetsoftheplan. 展开更多
关键词 expanded revised Action
在线阅读 下载PDF
Corrigendum to“Directional construction of Cu2S branch arrays for advanced oxygen evolution reaction”39(2019)61-67
15
作者 Shengjue Deng Yanbin Shen +6 位作者 Dong Xie Yangfan Lu Xiaolong Yu Liang Yang Xiuli Wang Xinhui Xia Jiangping Tu 《Journal of Energy Chemistry》 SCIE EI CAS CSCD 2021年第9期522-522,共1页
The authors regret that the Fig.S3 in supporting information of this published article needs to be revised.And the BET values are correct and unaffected.All the conclusions in the manuscript are unaffected by this uni... The authors regret that the Fig.S3 in supporting information of this published article needs to be revised.And the BET values are correct and unaffected.All the conclusions in the manuscript are unaffected by this unintentional error. 展开更多
关键词 branch SUPPORTING revised
在线阅读 下载PDF
Delta distribution of electronegative plasma predicted by reformed“spring oscillator”dynamic equation with dispersing force
16
作者 Shu-Xia Zhao Jing-Ze Li 《Chinese Physics B》 SCIE EI CAS CSCD 2021年第5期484-491,共8页
In our relevant paper[Zhao S X(2021)Chin.Phys.B 30055201],a delta distribution of negative ions is given by fluid simulation and preliminarily explained by decomposed anions transport equation.In the present work,firs... In our relevant paper[Zhao S X(2021)Chin.Phys.B 30055201],a delta distribution of negative ions is given by fluid simulation and preliminarily explained by decomposed anions transport equation.In the present work,first,the intrinsic connection between the electropositive plasma transport equation and spring oscillator dynamic equation is established.Inspired by this similarity,reformed“spring oscillator”equation with dispersing instead of restoring force that gives quasi-delta solution is devised according to the math embodied in the anion equation,which is of potential significance to the disciplines of atomic physics and astronomy as well.For solving the“diffusion confusion”the physics that determines the delta profile within the continuity equation is explored on the basis that recombination loss source term plays the role of drift flux,which is applicable for fluid model of low temperature plasma,but not the ordinary fluid dynamics.Besides,the math and physics revealed in this work predict that the ratio of recombination or attachment(for electrons)frequency versus the species diffusion coefficient is a very important parameter in determining the delta distribution,as it acts as the acceleration of object,according to the reformed oscillator equation.With this theory,the analogous delta profile of electrons density in the famous drift and ambi-polar diffusion heating mechanism of electronegative capacitively coupled plasma is interpreted. 展开更多
关键词 delta distribution electronegative plasma revised spring oscillator dispersing force
在线阅读 下载PDF
Theoretical Revision and Experimental Comparison of Quantum Yield for Transmission-Mode GaAlAs/GaAs Photocathodes
17
作者 SHI Feng ZHANG Yi-Jun +3 位作者 CHENG Hong-Chang ZHAO Jing XIONG Ya-Juan CHANG Ben-Kang 《Chinese Physics Letters》 SCIE CAS CSCD 2011年第4期105-107,共3页
The quantum yield formula for uniform-doping GaAIAs/GaAs transmission-mode photocathodes is revised by taking into account the light absorption in the window layer.By using the revised quantum yield formula,the domest... The quantum yield formula for uniform-doping GaAIAs/GaAs transmission-mode photocathodes is revised by taking into account the light absorption in the window layer.By using the revised quantum yield formula,the domestic and ITT's experimental quantum yield curves are fitted and the fitted curves match well with the experimental curves.In addition,the fit results show that the integral sensitivity and quantum yield of domestic image intensifier tube has achieved 2130μA/lm and 45%,nearly reaching ITT's third generation level in 2002,whereas the discrepancy in cathode performance is mainly embodied in the electron diffusion length and back interface recombination velocity. 展开更多
关键词 QUANTUM fitted revised
在线阅读 下载PDF
CALCULATION OF RELATIVE SENSITIVITY FACTOR IN AUGER ELECTRON SPECTROSCOPY
18
作者 ZHANG Ren-ji CHU Sheng-lin WU Zi-qin 《Chinese Physics Letters》 SCIE CAS 1985年第7期333-336,共4页
In this paper,the formula for calculating elemental relative sensitivity factor(S factor)has been deduced using the revised“full diffusion”model of electron scattering1.The calculated curves of S factors lie between... In this paper,the formula for calculating elemental relative sensitivity factor(S factor)has been deduced using the revised“full diffusion”model of electron scattering1.The calculated curves of S factors lie between the experimental curves obtained from the differential spectra2 and the integral spectra3. 展开更多
关键词 SPECTRA CURVES revised
在线阅读 下载PDF
Total cross sections for electron scattering from sulfur compounds
19
作者 谭晓明 王艳文 《Chinese Physics B》 SCIE EI CAS CSCD 2013年第2期218-222,共5页
The original additivity rule method cannot give good results for electron scattering from SO,SO2,SO2Cl2,SO2ClF,and SO2F2 molecules at low energy,because the electron-molecule scattering is simply reduced to electron-a... The original additivity rule method cannot give good results for electron scattering from SO,SO2,SO2Cl2,SO2ClF,and SO2F2 molecules at low energy,because the electron-molecule scattering is simply reduced to electron-atom scattering.Considering the difference between the bound atom in a molecule and the corresponding free atom,the original additivity rule is revised.With the revised additivity rule,the total cross sections for electron scattering from these molecules are calculated over a wide energy range below 3000 eV and compared with the available experimental and theoretical data.A better agreement between them is obtained. 展开更多
关键词 the revised additivity rule total cross sections electron scattering
在线阅读 下载PDF
THE INSTENSITY RATIOS I(L)/I(K) FROM Ge TO Sn MEASURED IN TEM USING EDS
20
作者 WU Zi-qin DUAN Jian-zhong 《Chinese Physics Letters》 SCIE CAS 1985年第6期257-260,共4页
The intensity ratios I(L)/I(K)from Ge to Sn have been measured in a Transmission electron microscope(TEM)using X-ray energy dispersive spectroscopy(EDS)at 40,80,100,120,160,200kV.The large discrepancy between experime... The intensity ratios I(L)/I(K)from Ge to Sn have been measured in a Transmission electron microscope(TEM)using X-ray energy dispersive spectroscopy(EDS)at 40,80,100,120,160,200kV.The large discrepancy between experimental and calculated values indicates that the formula of ionization cross-section should be revised. 展开更多
关键词 (L) revised
在线阅读 下载PDF
上一页 1 2 下一页 到第
使用帮助 返回顶部