期刊文献+
共找到21篇文章
< 1 2 >
每页显示 20 50 100
Effects of Land Use Change on Eco-environment in Hilly Area of Central Sichuan Basin——A Case Study of Yanting County, Sichuan Province 被引量:2
1
作者 Luo Huai-liang, Zhu Bo, Chen Guo-jie, Gao Mei-rongInstitute of Mountain Hazards and Environment, Chinese Academy of Sciences, Chengdu 610041, Sichuan, China College of Resources and Environment, Sichuan Normal University, Chengdu 610066, Sichuan, China 《Wuhan University Journal of Natural Sciences》 CAS 2003年第03B期981-986,共6页
With the artificial alder and cypress mixed forest being planted, there has been a marked land use change since 1970s' in Hilly Area of Central Sichuan Basin, China. Data from meteorological observations or posts ... With the artificial alder and cypress mixed forest being planted, there has been a marked land use change since 1970s' in Hilly Area of Central Sichuan Basin, China. Data from meteorological observations or posts operated over long time, measurement and calculation of NPP (net primary production) and biomass of biological community, and analysis of soil organic matter content show that the artificial alder and cypress mixed forest has outstanding eco-environmental effect: adjusting local climate, raising soil fertility, alleviating menace of drought, and raising NPP and biomass of biological community. It is very beneficial for improving ecological environment to afforest artificial alder and cypress mixed forest in populous Hilly Area of Central Sichuan Basin, China. Key Words: land use/land cover change (LUCC); eco-environmental effect; Hilly Area of Central Sichuan Basin; the artificial alder and cypress mixed forest 展开更多
关键词 of as for Sichuan Province effects of Land use Change on Eco-environment in Hilly Area of Central Sichuan Basin A Case Study of Yanting County on ECO
下载PDF
Assessing the Effect of Natural Controls and Land Use Change on Sediment Yield in a Major Andean River:The Magdalena Drainage Basin,Colombia 被引量:4
2
作者 Juan Dario +5 位作者 Restrepo James P. M. Syvitski 方海燕(译) 《AMBIO-人类环境杂志》 2006年第2期65-74,4,共10页
马格达莱纳河是哥伦比亚安第斯山区的一个世界级的河流网络,该河流年产沙量约为150Mt,是全世界10大主要产沙河流之一。在本研究中,我们探讨主要自然因子和人类活动对马格达莱纳河流域产沙模式的影响,重建该区森林砍伐和农业活动时... 马格达莱纳河是哥伦比亚安第斯山区的一个世界级的河流网络,该河流年产沙量约为150Mt,是全世界10大主要产沙河流之一。在本研究中,我们探讨主要自然因子和人类活动对马格达莱纳河流域产沙模式的影响,重建该区森林砍伐和农业活动时空模式,探讨土地利用变化与产沙趋势的关系。我们的研究结果表明,整个马格达莱纳河流域的产沙量可以用自然变量(包括径流量和最大河水流量)来解释。这两个因子解释了产沙量58%的变化。含沙率和土地利用的时间分析表明,在过去10~20年里流域侵蚀呈现增加的趋势。许多人类活动的影响,包括森林覆被在20年里减小了近40%.农业和牧场增加了65%、土壤保持差、开矿活动,以及城市化的加速,都促进了该地区域尺度上产沙量的增加。 展开更多
关键词 Assessing the effect of Natural Controls and Land use Change on Sediment Yield in a Major Andean River
下载PDF
An electrochemical study on the effects of marine fouling organisms on steel used in the sea
3
作者 Hong Xuebao,, Lin Ruimu, Li Dekai and Zheng Jiancheng(Receired February 6. 1990, accepted September 8. 1990) 《Acta Oceanologica Sinica》 SCIE CAS CSCD 1991年第2期263-269,共7页
-Study on the effects of microorganism secretive membrane and covering layer of macrofouling organisms-Balanus reticulatus, Ostrea plicatula, Membranipora, Corophium and Algae on the corrosion of carbon steel and low-... -Study on the effects of microorganism secretive membrane and covering layer of macrofouling organisms-Balanus reticulatus, Ostrea plicatula, Membranipora, Corophium and Algae on the corrosion of carbon steel and low-alloy steel by the determination of natural corrosive potentials, linear polarization and the polarization curver of dynamic potential scanning through an electrochemical equipment.The results show that the microorganism secretion membrane formed on sample surface has some protective role, during the initial period of exposure (about ten days). Then protective role decreases and corrosive rate increases with the lapse of immersion time. The protective role of some macrofouling organisms is shown in order as follows: Corophium> Balanus reticulatus>Algae>Membranipora>Ostrea plicatula. 展开更多
关键词 An electrochemical study on the effects of marine fouling organisms on steel used in the sea
下载PDF
Use of Agro wells for small scale irrigation and their effects on groundwater system in a hard rock aquifer:a case study in Kalaoya basin,SriLanka
4
《Global Geology》 1998年第1期52-52,共1页
关键词 rock use of Agro wells for small scale irrigation and their effects on groundwater system in a hard rock aquifer case
下载PDF
Control Effects of Bacillus subtilis DJ-6 and Pyraclostrobin Alone and in Combination Against Fusarium oxysporum 被引量:9
5
作者 吉沐祥 姚克兵 +3 位作者 李国平 吴祥 陈宏洲 庄义庆 《Agricultural Science & Technology》 CAS 2014年第11期2020-2025,共6页
[Objective] This study was conducted to screen a synergistic biological fungicide complex to control Fusarium wilt, reducing the use of chemical pesticides. [Method] The inhibitory effects of Bacil us subtilis DJ-6 an... [Objective] This study was conducted to screen a synergistic biological fungicide complex to control Fusarium wilt, reducing the use of chemical pesticides. [Method] The inhibitory effects of Bacil us subtilis DJ-6 and pyraclostrobin alone or in combination at five ratios against Fusarium oxysporum were detected by mea-suring mycelium growth rate in laboratory tests. The growth promotion and disease control effect of combined or single use of 20% pyraclostrobin and 2 ×1011 cfu/g B. subtilis DJ-6 WP at 1∶1 000, 1∶2 000 and 1∶3 000 dilutions were detected in field trials. [Result] The EC50 values of combined use of B. subtilis DJ-6 and pyra-clostrobin at ratios of 1∶1, 1∶2, 1∶3, 1∶4 and 1∶5 against F. oxysporum were 5.311 5, 4.008 6, 3.570 6, 3.350 9 and 3.218 9 μg/ml, with the synergistic ratios (SR) of 2.28, 1.77, 1.53, 1.64, 1.11, among which the synergetic effect at 1∶1 was the best. The fungicidal activity of pyraclostrobin was greater than that of B. subtilis DJ-6 in laboratory tests. Field trials revealed that al the 1∶1 000, 1∶2 000 and 1∶3 000 dilu-tions of 20% pyraclostrobin·2×1011 cfu/g B. subtilis DJ-6 WP in combination, 1∶1 000 dilution of 1 ×1012 cfu/g B. subtilis DJ-6 WP and 1∶2 000 dilution of 250 g/L pyra-clostrobin EC promoted the growth of strawberry by increasing plant height, leaf petiole, leaf blade area and stem diameter. Among them, the treatments with 1∶1 000 and 1∶2 000 of 20% pyraclostrobin · 2×1011 cfu/g B. subtilis DJ-6 WP in combina-tion had better effects than other treatments. The control effects of al the treat-ments were measured 30 and 80 d after fungicide application. The control effects of 1∶1 000 dilution of 20% pyraclostrobin and 2×1011 cfu/g B. subtilis DJ-6 in combina-tion were up to 100% and 93.11%, which were higher than those in al other treat-ments. The second highest control effects were found in the treatment with 1∶ 2 000 dilution of 20% pyraclostrobin and 2×1011 cfu/g B. subtilis DJ-6 in combination, they were 92.49% and 86.49%, higher than those in other treatments except the 1∶1 000 dilution of 20% pyraclostrobin and 2 ×1011 cfu/g B. subtilis DJ-6 in combination. The control effects of 1∶3 000 dilution of 20% pyraclostrobin and 2×1011 cfu/g B. subtilis DJ-6 in combination were 82.61% and 72.42%, higher than those in treatment with 1∶1 000 dilution of 1×1012 cfu/g B. subtilis DJ-6 WP, but lower than those in treat-ment with 1∶2 000 dilution of 25% pyraclostrobin EC. [Conclusion] Al the results re-vealed that the combination use of 20% pyraclostrobin and 2 ×1011 cfu/g B. subtilis DJ-6 WP at 1∶1 000 to 1∶2 000 dilution had better control effect against strawberry Fusarium wilt. 展开更多
关键词 Strawberry Fusarium wilt Bacil us subtilis DJ-6 Pyraclostrobin use in combination Antibacterial activity Plant growth traits Field control effects
下载PDF
Combining CLUE-S and SWAT Models to Forecast Land Use Change and Non-point Source Pollution Impact at a Watershed Scale in Liaoning Province, China 被引量:15
6
作者 LIU Miao LI Chunlin +3 位作者 HU Yuanman SUN Fengyun XU Yanyan CHEN Tan 《Chinese Geographical Science》 SCIE CSCD 2014年第5期540-550,共11页
Non-point source(NPS) pollution has become a major source of water pollution. A combination of models would provide the necessary direction and approaches designed to control NPS pollution through land use planning. I... Non-point source(NPS) pollution has become a major source of water pollution. A combination of models would provide the necessary direction and approaches designed to control NPS pollution through land use planning. In this study, NPS pollution load was simulated in urban planning, historic trends and ecological protection land use scenarios based on the Conversion of Land Use and its Effect at Small regional extent(CLUE-S) and Soil and Water Assessment Tool(SWAT) models applied to Hunhe-Taizi River Watershed, Liaoning Province, China. Total nitrogen(TN) and total phosphorus(TP) were chosen as NPS pollution indices. The results of models validation showed that CLUE-S and SWAT models were suitable in the study area. NPS pollution mainly came from dry farmland, paddy, rural and urban areas. The spatial distribution of TN and TP exhibited the same trend in 57 sub-catchments. The TN and TP had the highest NPS pollution load in the western and central plains, which concentrated the urban area and farm land. The NPS pollution load would increase in the urban planning and historic trends scenarios, and would be even higher in the urban planning scenario. However, the NPS pollution load decreased in the ecological protection scenario. The differences observed in the three scenarios indicated that land use had a degree of impact on NPS pollution, which showed that scientific and ecologically sound construction could effectively reduce the NPS pollution load in a watershed. This study provides a scientific method for conducting NPS pollution research at the watershed scale, a scientific basis for non-point source pollution control, and a reference for related policy making. 展开更多
关键词 Conversion of Land use and its effect at Small regional extent (CLUE-S) Hunhe-Taizi River Watershed non-point source pollution Soil and Water Assessment Tool (SWAT)
下载PDF
A Step Forward toward Effectively Using Hyperspectral IR Sounding Information in NWP 被引量:5
7
作者 Jun LI Wei HAN 《Advances in Atmospheric Sciences》 SCIE CAS CSCD 2017年第11期1263-1264,共2页
Satellite-based atmospheric sounding measurements with high spectral resolution or from hyperspectral infrared (IR) sounders are important global observations for improving weather forecasts through assimilating the... Satellite-based atmospheric sounding measurements with high spectral resolution or from hyperspectral infrared (IR) sounders are important global observations for improving weather forecasts through assimilating them into operational numerical weather prediction (NWP) systems. 展开更多
关键词 In A Step Forward toward effectively Using Hyperspectral IR Sounding Information in NWP
下载PDF
Bias Effects on the Reynolds Stress Using the Multi-Purpose Probe in IR-T1 Tokamak
8
作者 M.Lafouti M.Ghoranneviss 《Chinese Physics Letters》 SCIE CAS CSCD 2016年第1期88-91,共4页
The effect of the positive bias on Reynolds stress (RS) and its effect on the radial turbulent transport at the edge plasma (r/a =0.9) and scrape-off layer (SOL) region of plasma in tokamak are investigated. The... The effect of the positive bias on Reynolds stress (RS) and its effect on the radial turbulent transport at the edge plasma (r/a =0.9) and scrape-off layer (SOL) region of plasma in tokamak are investigated. The radial and poloidal electric fields (Sr, Ep) and ion saturation current (Is) are measured by multi-purpose probe (MPP). This probe is fabricated and constructed for the first time in the IR-T1 tokamak. The most advantage of this probe is that the variations of Er and Ep can be measured in different radii at the single shot. Thus the information of different radii can be compared with high precision. The bias voltage is fixed at Vbias = 200 V and it has been applied with the limiter bias that is fixed in r/a = 0.9. Moreover, the phase difference between radial and poloidal electric fields, and temporal evolution of the RS .spectrum detected by MPP are calculated. RS magnitude on the edge (r/a = 0.9) is more than its value in the SOL (r/a = 1.02). With the applied bias 200 V, ItS and the magnitude of the phase difference between Er and Ep are increased, while the radial turbulent transport is decreased simultaneously. Thus it can be concluded that RS affects radial turbulence. Temporal evolution of the RS spectrum shows that the frequency of RS is increased and reaches its highest value at r/a=0.9 in the presence of bias. 展开更多
关键词 of is RS been in Bias effects on the Reynolds Stress Using the Multi-Purpose Probe in IR-T1 Tokamak on IR
原文传递
The effect of using in ternet web site in promoting non-remunerated blood donation
9
《中国输血杂志》 CAS CSCD 2001年第S1期324-,共1页
关键词 The effect of using in ternet web site in promoting non-remunerated blood donation
下载PDF
Evaluation of the Effects of Cypermethrin on Female Reproductive Function by Using Rabbit Model and of the Protective Role of Chinese Propolis 被引量:3
10
作者 AE Khatab NM Hashem +2 位作者 LM El-Kodary FM Lotfy GA Hassan 《Biomedical and Environmental Sciences》 SCIE CAS CSCD 2016年第10期762-766,共5页
The prophylactic effects of Chinese propolis against cypermethrin toxicity were evaluated by performing ovary and uterus histopathology, as well as by characterizing ovarian function, embryos, and litters. Cypermethri... The prophylactic effects of Chinese propolis against cypermethrin toxicity were evaluated by performing ovary and uterus histopathology, as well as by characterizing ovarian function, embryos, and litters. Cypermethrin induced atypia in the ovary and uterus, and decreased the ovulation sites and the number of embryos. Cypermethrin-induced oxidative stress during pregnancy, decreased the parturition rate as well as the number and weight of offspring and increased the incidence of morphological malformations in the offspring. Administration of propolis to cypermethrin-treated animals mitigated cypermethrin-induced reproductive toxicity. 展开更多
关键词 Evaluation of the effects of Cypermethrin on Female Reproductive Function by Using Rabbit Model and of the Protective Role of Chinese Propolis Pro GPX
下载PDF
Control study of short-term curative effect of minimally invasive total hip arthroplasty using metal-on-metal large-diameter femoral head for the elderly patients with femoral neck fractures
11
作者 何锐 《外科研究与新技术》 2011年第2期116-117,共2页
Objective To discuss the postoperative curative effects of two surgical techniques of minimally invasive total hip arthroplasty (THA) using metal-on-metal largediameter and conventional diameter femoral head for the e... Objective To discuss the postoperative curative effects of two surgical techniques of minimally invasive total hip arthroplasty (THA) using metal-on-metal largediameter and conventional diameter femoral head for the elderly patients 展开更多
关键词 THA head Control study of short-term curative effect of minimally invasive total hip arthroplasty using metal-on-metal large-diameter femoral head for the elderly patients with femoral neck fractures
下载PDF
上海市医疗卫生机构职工休息室建设需求与对策建议
12
作者 余荣 杨思佳 +4 位作者 姜轶岚 李嘉慧 刘珊珊 陈健 何园 《中国卫生资源》 CSCD 北大核心 2023年第6期725-730,共6页
目的调查分析上海市医疗卫生机构职工休息室建设需求和管理现状,为改善医务职工的工作环境和工作条件提供方法和经验。方法对各级医院和医疗急救中心的医务职工进行线上电子问卷调查,内容包括休息室现状及对休息室需求等,共回收有效问卷... 目的调查分析上海市医疗卫生机构职工休息室建设需求和管理现状,为改善医务职工的工作环境和工作条件提供方法和经验。方法对各级医院和医疗急救中心的医务职工进行线上电子问卷调查,内容包括休息室现状及对休息室需求等,共回收有效问卷1434份。对9家医疗卫生机构开展现场调查,并与休息室建设负责人、管理负责人等15名相关人员进行访谈。结果所调查的医务职工中,13.7%没有时间休息,16.9%在休息室中休息,医疗机构现有职工休息室建设存在设置不均衡、总体数量少、使用率有待进一步提高等问题。医务人员对休息室的需求主要集中于面积、布局、室内环境、功能等方面,其中不同工作特性医务人员的休息需求有所不同。医务职工休息室建设与推行难点主要为用房紧张、法规标准不明确、管理困难、医务职工休息需求不被重视。结论在医务职工休息室规划建设上,建议加大政策支持力度,建立规范化管理制度,并通过加强组织领导、多方协同合作,确保休息室建设改善工作能有效落实。在具体建设方面,应满足医务职工多元需求,可因地制宜规划设计、合理划分功能分区。此外,还应重视宣传总结,营造“健康工作,科学休息”的积极氛围。 展开更多
关键词 医疗卫生机构medical and healthcare institution 职工休息室staff lounge 医务人员medical staff 建设establishment 使用效果effect of use
下载PDF
Could We Use Clinical Benefit to Evaluate the Effects of Chinese Medicine on the Treatment of Cancer? 被引量:3
13
作者 李萍萍 《Chinese Journal of Integrative Medicine》 SCIE CAS 2010年第1期9-10,共2页
The patients, who cannot endure the chemotherapy anymore, or internal disease or present drug resistance, normally use CM for improving their physical conditions and inhibiting tumor. CM has got excellent reputation b... The patients, who cannot endure the chemotherapy anymore, or internal disease or present drug resistance, normally use CM for improving their physical conditions and inhibiting tumor. CM has got excellent reputation because of the effects. Nonetheless, few clinical articles of CM to treat cancer are published on major international journals up to now. 展开更多
关键词 Could We use Clinical Benefit to Evaluate the effects of Chinese Medicine on the Treatment of Cancer WE QOL
原文传递
Effect of a pain diary use on recovery from acute whiplash injury: a cohort study
14
作者 Robert FERRARI Deon LOUW 《Journal of Zhejiang University-Science B(Biomedicine & Biotechnology)》 SCIE CAS CSCD 2013年第11期1049-1053,共5页
Previously,it was shown that the use of a symptom diary for two weeks,even in generally healthy subjects,results in increased recall of daily symptoms and increased perception of symptom severity(Ferrari and Russell,2... Previously,it was shown that the use of a symptom diary for two weeks,even in generally healthy subjects,results in increased recall of daily symptoms and increased perception of symptom severity(Ferrari and Russell,2010).In that study,generally healthy female subjects were asked to recall symptoms experienced in the previous two weeks,after keeping a symptom diary for two weeks,while a control group was asked to recall symptoms experienced in the previous two weeks without having kept a symptom diary.While both groups had 展开更多
关键词 a cohort study effect of a pain diary use on recovery from acute whiplash injury
原文传递
Multi-wavelength erbium-doped fiber laser using four-wave mixing effect in doped fiber 被引量:3
15
作者 N. S. Shahabuddin Z. Yusoff +1 位作者 H. Ahmad S. W. Harun 《Chinese Optics Letters》 SCIE EI CAS CSCD 2011年第6期80-81,共2页
We demonstrate a multi-wavelength erbium-doped fiber laser (EDFL) using erbium gain and four-wave mixing (FWM) effect in a piece of erbium-doped fiber (EDF) with high erbium ion concentration. The EDF has a pump... We demonstrate a multi-wavelength erbium-doped fiber laser (EDFL) using erbium gain and four-wave mixing (FWM) effect in a piece of erbium-doped fiber (EDF) with high erbium ion concentration. The EDF has a pump absorption rate of 24.6 dB/m at 979 nm and is bi-directionally pumped by 980-nm laser diodes. FWM effect redistributes the energy of different oscillating lines and causes multi-wavelength operation. The laser generates more than 22 lines of optical comb with a line spacing of approximately 0.10 nm at the 1569-nm region using only 1.5-m-long EDF. 展开更多
关键词 EDF FWM Multi-wavelength erbium-doped fiber laser using four-wave mixing effect in doped fiber LENGTH WAVE
原文传递
Effects of Chirped Super-Gaussian Pulses on Optical Communication System Using Midway Optical Phase Conjugation 被引量:1
16
作者 Yang Bu Xiangyang Zhang Xiangzhao Wang Shanghai Institute of Optics and Fine Mechanics, The Chinese Academy of Sciences,P.R.China 《光学学报》 EI CAS CSCD 北大核心 2003年第S1期63-64,共2页
Relationship between the initial chirp of super-Gaussian pulse and dispersion and nonlinearity effects of a single-mode fiber in the optical communication system using midway optical phase conjugation is analyzed. The... Relationship between the initial chirp of super-Gaussian pulse and dispersion and nonlinearity effects of a single-mode fiber in the optical communication system using midway optical phase conjugation is analyzed. The results of numerical simulations are useful for improving compensation for pulse distortion. 展开更多
关键词 of in be OPC effects of Chirped Super-Gaussian Pulses on Optical Communication System Using Midway Optical Phase Conjugation for
原文传递
Understanding of strain effects in the electrochemical reduction of CO_2:Using Pd nanostructures as an ideal platform 被引量:1
17
《Science Foundation in China》 CAS 2017年第4期42-,共1页
With the support by the National Natural Science Foundation of China,a collaborative study by the research groups led by Prof.Zeng Jie(曾杰)and Prof.Yang Jinlong(杨金龙),both from Hefei National Laboratory for Physica... With the support by the National Natural Science Foundation of China,a collaborative study by the research groups led by Prof.Zeng Jie(曾杰)and Prof.Yang Jinlong(杨金龙),both from Hefei National Laboratory for Physical Sciences at the Microscale,University of Science and Technology of China, 展开更多
关键词 PD Understanding of strain effects in the electrochemical reduction of CO2:Using Pd nanostructures as an ideal platform CO
原文传递
An analytical method for quantitative estimation of the cytotoxicity of dental alloys using MTT assay,ICP analysis and effective cytotoxicity calculation
18
作者 Lü Xiao Ying and H.F.Kappert 《Chinese Medical Journal》 SCIE CAS CSCD 1997年第12期47-47,共1页
The two most important criteria for dental materials are their biofunctional and biocompatible endurance within the anticipated life-span of the dental restoration in the mouth. Biocompatibility relates mainly to the ... The two most important criteria for dental materials are their biofunctional and biocompatible endurance within the anticipated life-span of the dental restoration in the mouth. Biocompatibility relates mainly to the allergenicity and the toxicity of the material. To test the non-specific toxicity of dental materials, in vitro cell culture assays have been developed. For in vitro screening, such tests are recommended to check the cytotoxicity of dental materials (ISO 10993 5). Various studies have already been performed to quantitatively determine the cytotoxicity level of dental alloys. However, as long as only dental alloys and the cell culture technique are applied, it is not possible to determine which of the alloying elements cause the cytotoxicity. Therefore, an analytical method is needed. Wataha et al determined in 1991 the TC50 values of 9 metal cations of various dental casting alloys, using cell culture methods. Kapert et al reported in 1994 a complex in vitro test concept, where the ICP analysis (inductively coupled plasma emission spectroscopy) was introduced to measure the trace elements extracted from various alloys. Experimentelle Zahnheilkunde, Universitts ZMK Klinik Freiburg, Germany (Lü XY and Kappert HF) The aim of the present study was to find a relation between the ICP results, the TC50 value of metal cations, and the cytotoxicity of dental alloys. The cytotoxicity levels of various dental alloys and the TC50 values of 10 metal cations were established using the MTT assay, an effective cell culture of method. Then, the concentrations of the corrosively soluted metal cations in the extracts of the alloys were measured using the ICP method. From all these experimental results it was found that the relation between the effective cytotoxicity Z eff of an alloy, the concentrations C i of i th trace element and the TC50 values T Ci of the i th metal cation can approximately be expressed by Z eff =∑iC i2·T Ci . Two significant applications of this expression are a) The cytotoxicity of an alloy can be estimated by ICP analysis of the extract if the TC50 values of the trace elements are know. b) The cytotoxicity of a new-developed-alloy can be estimated in advance, according to the alloying components. 展开更多
关键词 MTT ICP An analytical method for quantitative estimation of the cytotoxicity of dental alloys using MTT assay ICP analysis and effective cytotoxicity calculation
原文传递
Suppression effect of jet flow on pulsating pressure of cavity using scale-adaptive simulation model
19
作者 YU Peixun BAI Junqiang +2 位作者 GUO Bozhi HAN Xiao HAN Shanshan 《Chinese Journal of Acoustics》 CSCD 2015年第1期67-83,共17页
The suppression of the aerodynamic noise in the cavity has a great significance to solve relevant puzzles of weapon bays. Acoustic field of the standard cavity model is simulated by using the computational fluid dynam... The suppression of the aerodynamic noise in the cavity has a great significance to solve relevant puzzles of weapon bays. Acoustic field of the standard cavity model is simulated by using the computational fluid dynamics technology based on scale-adaptive simulation (SAS) model. The results obtained by the proposed method in this paper show reasonable agreement with experiments. On the basis of this, effect of different jet flow rates on the time-averaged variables, turbulent kinetic energy, root mean square (RMS) of sound pressure, sound sources distribution and the pulsating pressure distribution in the cavity is studied. The analysis shows that the jet flow has great influence on the cavity flow field and the distribution of pulsating pressure RMS by changing the morphology of the shear layer. The most obvious of these measures is spout4 configuration, the influence mainly in the form of reducing the pulsating pressure of the whole cavity and changing the sound pressure level in the far field. The results show that different jet flow rates have different control effects on pulsating pressure in the cavity and sound pressure level in the far field. Furthermore, the jet flow rates and the suppression effect on the pulsating pressure have no linear relation. 展开更多
关键词 flow Suppression effect of jet flow on pulsating pressure of cavity using scale-adaptive simulation model
原文传递
Ab initio studies on the electronic structure of the complexes containing Mo——S bond using relativistic effective core potentials
20
作者 MA Zhong-Xin DAI Shu-Shan Department of Chemistry,Yunnan University,Kunming 《Acta Chimica Sinica English Edition》 SCIE CAS CSCD 1989年第3期201-208,共1页
An ab initio calculation was performed on the electronic structures of MoS,MoS_4^(2-) and Mo_2S_2 using relativistic effective core potential(RECP)for molybdenum,and non-relativistic ECP for sulfur.We predicted that t... An ab initio calculation was performed on the electronic structures of MoS,MoS_4^(2-) and Mo_2S_2 using relativistic effective core potential(RECP)for molybdenum,and non-relativistic ECP for sulfur.We predicted that the equilibrium bond length and the dissociation energy of MoS in ground state are 3.89 a.u.and 4.67 eV,respectively,and that the bond is a triple-bond.The ground state of MoS_4^(2-) in Td symmetry is ~1A_1 and π-bonding dominates σ-donation in the molybdenum- sulfur interaction.The Mo_2S_2 is a model contracted from bi-nuclear sulfur-bridged clusters,and the bonding orbitals 1 b_(1u),1b_1g and 1b_2g make the dominant contribution to the stabilization of sulfur- bridged species. 展开更多
关键词 Ab initio studies on the electronic structure of the complexes containing Mo S bond using relativistic effective core potentials core
全文增补中
上一页 1 2 下一页 到第
使用帮助 返回顶部