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<i>Lactobacillus</i>GG Supplementation on Anti-<i>Helicobacter pylori</i>Therapy-Related Side Effects and Eradication Rates: A Meta-Analysis
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作者 Shristi Shakya Guoqiang Zhang +1 位作者 Huajian Hu Zhongyue Li 《Open Journal of Internal Medicine》 2015年第4期96-105,共10页
Background: Concerns still exist with respect to unsatisfactory eradication rates and/or therapy-associated side effects for the use of standard triple therapy in the treatment of Helicobacter pylori infection, which ... Background: Concerns still exist with respect to unsatisfactory eradication rates and/or therapy-associated side effects for the use of standard triple therapy in the treatment of Helicobacter pylori infection, which prompts considerable interest in new therapy. We systematically reviewed the literature to investigate whether Lactobacillus GG as supplementation to standard triple therapy could improve H. pylori eradication rates and/or reduce therapy-associated side effects. Methods: PubMed, EMBASE, the Cochrane Central Register of Controlled Trials (CENTRAL) were systematically searched from their inception to August 4, 2015 for randomized controlled trials (RCTs). The language was restricted to English only. Results: Four RCTs involving a total of 305 participants (including 83 children) were included. Lactobacillus GG given along with triple therapy significantly reduced the risk of overall H. pylori therapy-related adverse effects (three RCTs, n = 221, RR 0.59, 95% CI 0.45 - 0.78), particularly of diarrhea (four RCTs, n = 285, RR 0.23, 95% CI 0.11 - 0.47), bloating (four RCTs, n = 289, RR 0.61, 95% CI 0.41 - 0.90), and taste disturbance (four RCTs, n = 288, RR 0.38, 95% CI 0.23 - 0.62). There were no significant differences between groups in the risk of other adverse effects. No beneficial effects of Lactobacillus GG were observed for H. pylori eradication rates (four RCTs, n = 284, RR 0.99, 95% CI 0.88 - 1.13). Conclusion: Current evidence indicates that Lactobacillus GG administered along with standard triple therapy is a feasible way to reduce therapy-related side effects, particularly diarrhea, bloating, and taste disturbance. However, Lactobacillus GG shows no effects on eradication rates. 展开更多
关键词 LACtoBACILLUS GG Helicobacter pylori side effects Eradication rate META-ANALYSIS
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Approach to estimating non-point pollutant load removal rates based on water environmental capacity: a case study in Shenzhen 被引量:1
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作者 刘梁 刘安 管运涛 《Journal of Southeast University(English Edition)》 EI CAS 2014年第2期143-149,共7页
An innovative approach based on water environmental capacity for non-point source NPS pollution removal rate estimation was discussed by using both univariate and multivariate data analysis.Taking Shenzhen city as the... An innovative approach based on water environmental capacity for non-point source NPS pollution removal rate estimation was discussed by using both univariate and multivariate data analysis.Taking Shenzhen city as the study case a 67% to 74% NPS pollutant load removal rate can lead to meeting the chemical oxygen demand COD pollution control target for most watersheds.In contrast it is hardly to achieve the ammonia nitrogen NH4-N total phosphorus TP and biological oxygen demand BOD5 pollution control target by simply removing NPS pollutants. This highlights that the pollution control strategies should be taken according to different pollutant species and sources in different watersheds rather than one-size-fits-all . 展开更多
关键词 environmental capacity estimation non-point source (NPS) pollution removal rate control strategy
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On investigating the soda-lime shot blasting of AZ31 alloy:Effects on surface roughness,material removal rate,corrosion resistance,and bioactivity 被引量:2
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作者 Gurmider Singh Sunpreet Singh +1 位作者 Chander Prakash Seeram Ramakrishna 《Journal of Magnesium and Alloys》 SCIE EI CAS CSCD 2021年第4期1278-1290,共13页
In the present study,a novel method of surface finish improvement is proposed using shot blasting of soda lime(SBSL)beads on the Mg-AZ31 alloy.The effect of the soda blasting process parameters,such as blast pressure,... In the present study,a novel method of surface finish improvement is proposed using shot blasting of soda lime(SBSL)beads on the Mg-AZ31 alloy.The effect of the soda blasting process parameters,such as blast pressure,stand-off distance,and blast duration,have been studied in-response of material removal rate(MRR)and surface roughness(SR)and corresponding statistical models have been obtained.The multi-objective optimization has also been performed to obtain parameters for maximum MRR and minimum SR.The corrosion behavior of the treated specimens has been performed to study their in-vitro biodegradability in simulated body fluid(SBF)for 1,3,7,10,15,and 21 days.The wettability study of the SBSL treated samples has been investigated using sessile drop methodology.Further,cell adhesion test has also been performed to study the biocompatibility characteristics of the SBSL treated samples using Huh7 liver cell lines.Based on obtained quantitative data as well as scanning electron microscopy analysis of treated samples,the SBSL treatment of the AZ31 alloy has been found highly useful in producing biocompatibility surfaces along with desirable morphological features. 展开更多
关键词 AZ31 Soda-lime Surface roughness Material removal rate Corrosion WETTABILITY BIOCOMPATIBILITY
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EFFECTS OF RATE OF ADDITION AND TENIPERATURE ON THE ENANTIOSELECTIVITY IN BORANE REDUCTION OF KETONES CATALYZED BY CHIRAL OXAZABOROLIDINE
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作者 Yao Zhong JIANG Yong +1 位作者 QIN snd Ai Qiao MIChengdu Institute of Organic Chemtetry, A cademia Sinica, Chengdu 610041 《Chinese Chemical Letters》 SCIE CAS CSCD 1995年第1期9-12,共4页
The exoellent enantioselectivity with o. p. >99% in asymmetrio borane reduction of acetophenone catalyzed by (4S, 5R ) 4, 5-diphenyi-1. 3. 2-oxazaborolidine has been achieved via the important modincation of the ... The exoellent enantioselectivity with o. p. >99% in asymmetrio borane reduction of acetophenone catalyzed by (4S, 5R ) 4, 5-diphenyi-1. 3. 2-oxazaborolidine has been achieved via the important modincation of the reaction conditions. 展开更多
关键词 rate REDUCTION BORANE BY CATALYZED CHIRAL effects IN KEtoNES OF
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Laser-assisted Simulation of Dose Rate Effects of Wide Band Gap Semiconductor Devices
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作者 TANG Ge XIAO Yao +3 位作者 SUN Peng LIU Jingrui ZHANG Fuwang LI Mo 《原子能科学技术》 EI CAS CSCD 北大核心 2023年第12期2314-2325,共12页
Laser-assisted simulation technique has played a crucial role in the investigation of dose rate effects of silicon-based devices and integrated circuits,due to its exceptional advantages in terms of flexibility,safety... Laser-assisted simulation technique has played a crucial role in the investigation of dose rate effects of silicon-based devices and integrated circuits,due to its exceptional advantages in terms of flexibility,safety,convenience,and precision.In recent years,wide band gap materials,known for their strong bonding and high ionization energy,have gained increasing attention from researchers and hold significant promise for extensive applications in specialized environments.Consequently,there is a growing need for comprehensive research on the dose rate effects of wide band gap materials.In response to this need,the use of laser-assisted simulation technology has emerged as a promising approach,offering an effective means to assess the efficacy of investigating these materials and devices.This paper focused on investigating the feasibility of laser-assisted simulation to study the dose rate effects of wide band gap semiconductor devices.Theoretical conversion factors for laser-assisted simulation of dose rate effects of GaN-based and SiC-based devices were been provided.Moreover,to validate the accuracy of the conversion factors,pulsed laser and dose rate experiments were conducted on GaN-based and SiC-based PIN diodes.The results demonstrate that pulsed laser radiation andγ-ray radiation can produce highly similar photocurrent responses in GaN-based and SiC-based PIN diodes,with correlation coefficients of 0.98 and 0.974,respectively.This finding reaffirms the effectiveness of laser-assisted simulation technology,making it a valuable complement in studying the dose rate effects of wide band gap semiconductor devices. 展开更多
关键词 laser-assisted simulation dose rate effect wide band gap semiconductor conversion factor
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Effects of CPA Loading Temperature and Removal Protocols on MNC Vitrification
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作者 Yang JIN~1 Xue-Hu MA~1 Dan GE~1 Tian-Qing LIU~1 Zhan-Feng CUI~(1,2)1(Stem Cell and Tissue Engineering Laboratory, Dalian University of Technology, Dalian 116024, China)2(Department of Engineering Science, Oxford University, Parks Road, Oxford OX1 3PJ, UK) 《生物医学工程学杂志》 EI CAS CSCD 北大核心 2005年第S1期87-88,共2页
关键词 CPA MNC effects of CPA Loading Temperature and removal Protocols on MNC Vitrification
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Do the RMB exchange rate and global commodity prices have asymmetric or symmetric effects on China’s stock prices?
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作者 Shaobo Long Mengxue Zhang +1 位作者 Keaobo Li Shuyu Wu 《Financial Innovation》 2021年第1期1030-1050,共21页
With the rapid expansion of the RMB exchange rate’s floating range,the effects of the RMB exchange rate and global commodity price changes on China’s stock prices are likely to increase.This study uses both auto reg... With the rapid expansion of the RMB exchange rate’s floating range,the effects of the RMB exchange rate and global commodity price changes on China’s stock prices are likely to increase.This study uses both auto regressive distributed lag(ARDL)and nonlinear ARDL(NARDL)approaches to explore the symmetric and asymmetric effects of the RMB exchange rate and global commodity prices on China’s stock prices.Our findings show that without considering the critical variable of global commodity prices,there is no cointegration relationship between the RMB exchange rate and China’s stock prices,and the coefficient of the RMB exchange rate is not statistically significant.However,when we introduce global commodity prices into the NARDL model,the result shows that the RMB exchange rate has a negative effect on China’s stock prices,that there indeed exists a long-run cointegration relationship among the RMB exchange rate,global commodity prices,and stock prices in the NARDL model,and that global commodity price changes have an asymmetric effect on China’s stock prices in the long run.Specifically,China’s stock prices are more sensitive to increases than decreases in global commodity prices.Thus,increases in global commodity prices cause China’s stock prices to decline sharply.In contrast,the same magnitude of decline in global commodity prices induces a smaller increase in China’s stock prices. 展开更多
关键词 RMB exchange rate Global commodity prices China’s stock prices Asymmetric effects
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Dose-rate effects of low-dropout voltage regulator at various biases
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作者 Wang Yiyuan Lu Wu +4 位作者 Ren Diyuan Zheng Yuzhan Gao Bo Chen Rui Fei Wuxiong 《Nuclear Science and Techniques》 SCIE CAS CSCD 2010年第6期352-356,共5页
A low-dropout voltage regulator,LM2941,was irradiated by ^(60)Coγ-rays at various dose rates and biases for investigating the total dose and dose rate effects.The radiation responses show that the key electrical para... A low-dropout voltage regulator,LM2941,was irradiated by ^(60)Coγ-rays at various dose rates and biases for investigating the total dose and dose rate effects.The radiation responses show that the key electrical parameters, including its output and dropout voltage,and the maximum output current,are sensitive to total dose and dose rates, and are significantly degraded at low dose rate and zero bias.The integrated circuits damage change with the dose rates and biases,and the dose-rate effects are relative to its electric field. 展开更多
关键词 剂量率效应 低压降稳压器 偏见 低压差稳压器 输入输出 电气参数 输出电流 低剂量率
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IMPROVING MATERIAL REMOVAL RATE OF BRITTLE CERAMICS THROUGH HONING INCIDENTAL TENSILE STRESSES
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作者 于爱兵 徐燕申 +1 位作者 林彬 王龙山 《Transactions of Tianjin University》 EI CAS 1998年第2期41-44,共4页
The stress intensity factors and stress conditions of machining cracks are analyzed by fracture mechanics on the basis of honing characteristics and of brittle ceramic mechanical behavior.Because the honing incidental... The stress intensity factors and stress conditions of machining cracks are analyzed by fracture mechanics on the basis of honing characteristics and of brittle ceramic mechanical behavior.Because the honing incidental tensile stresses effectively decrease the critical grinding stresses and increase the stress intensity factors of machining cracks,the honing process can be carried out easily.The results show that honing can be an efficient machining method for brittle materials. 展开更多
关键词 CERAMICS HONING incidental tensile stress material removal rate
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Agglomeration rate and action forces between atomized particles of agglomerator and inhaled-particles from coal combustion 被引量:12
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作者 WEIFeng ZHANGJun-ying ZHENGChu-guang 《Journal of Environmental Sciences》 SCIE EI CAS CSCD 2005年第2期335-339,共5页
In order to remove efficiently haled-particles emissions from coal combustions, a new way was used to put forward the process of agglomeration and the atomization was produced by the nozzle and then sprayed into the ... In order to remove efficiently haled-particles emissions from coal combustions, a new way was used to put forward the process of agglomeration and the atomization was produced by the nozzle and then sprayed into the flue before precipitation devices of power station boiler in order to make inhaled-particles agglomerate into bigger particles, which can be easily removed but not change existing running conditions of boiler. According to this idea, a model is set up to study agglomeration rate and effect forces between fly ash inhaled-particles and atomized agglomerator particles. The developed agglomeration rate was expressed by relative particle number decreasing speed per unit volume. The result showed that viscosity force and flow resistance force give main influences on agglomeration effect of inhaled-particles, while springiness force and gravity have little effect on agglomeration effect of theirs. Factors influencing the agglomeration rate and effect forces are studied, including agglomerator concentration, agglomerator flux and agglomerator density, atomized-particles diameters and inhaled-particles diameter and so on. 展开更多
关键词 inhaled particles agglomerator effect forces agglomeration rate
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Application of subsurface wastewater infiltration system to on-site treatment of domestic sewage under high hydraulic loading rate 被引量:7
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作者 Ying-hua Li Hai-bo Li +2 位作者 Xin-yang Xu Xuan Gong Yong-chun Zhou 《Water Science and Engineering》 EI CAS CSCD 2015年第1期49-54,共6页
In order to enhance the hydraulic loading rate (HLR) of a subsurface wastewater infiltration system (SWIS) used in treating domestic sewage, the intermittent operation mode was employed in the SWIS. The results sh... In order to enhance the hydraulic loading rate (HLR) of a subsurface wastewater infiltration system (SWIS) used in treating domestic sewage, the intermittent operation mode was employed in the SWIS. The results show that the intermittent operation mode contributes to the improvement of the HLR and the pollutant removal rate. When the wetting-drying ratio (RwD) was 1.0, the pollutant removal rate increased by (13.6 ± 0.3)% for NH3-N, (20.7 ± 1.1)% for TN, (18.6± 0.4)% for TP, (12.2 ± 0.5)% for BOD, (10.1 ± 0.3)% for COD, and (36.2 ± 1.2)% for SS, compared with pollutant removal rates under the continuous operation mode. The pollutant removal rate declined with the increase of the HLR. The effluent quality met The Reuse of Urban Recycling Water - Water Quality Standard for Scenic Environment Use (GB/T 18921-2002) even when the HLR was as high as 10 cm/d. Hydraulic conductivity, oxidation reduction potential (ORP), the quantity of nitrifying bacteria, and the pollutant removal rate of NH3-N increased with the decrease of the RWD. For the pollutant removal rates of TP, BOD, and COD, there were no significant difference (p 〈 0.05) under different RwDS. The suggested RWD was 1.0. Relative contribution of the pretreatment and SWlS to the pollutant removal was examined, and more than 80% removal of NH3-N, TN, TP, COD, and BOD occurred in the SWIS. 展开更多
关键词 Domestic sewage Subsurface wastewater infiltration system Intermittent operation mode Hydraulic loading rate Pollutant removal rate
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Nitrogen removal efficiency of iron-carbon micro-electrolysis system treating high nitrate nitrogen organic pharmaceutical wastewater 被引量:4
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作者 周健 段送华 +1 位作者 陈垚 胡斌 《Journal of Central South University》 SCIE EI CAS 2009年第S1期368-373,共6页
The nitrate nitrogen removal efficiency of iron-carbon micro-electrolysis system was discussed in treating pharmaceutical wastewater with high nitrogen and refractory organic concentration. The results show that the g... The nitrate nitrogen removal efficiency of iron-carbon micro-electrolysis system was discussed in treating pharmaceutical wastewater with high nitrogen and refractory organic concentration. The results show that the granularity of fillings,pH,volume ratios of iron-carbon and gas-water,and HRT. have significant effects on the nitrogen removal efficiency of iron-carbon micro-electrolysis system. The iron-carbon micro-electrolysis system has a good removal efficiency of pharmaceutical wastewater with high nitrogen and refractory organic concentration when the influent TN,NH4+-N,NO3--N and BOD5/CODCr are 823 mg/L,30 mg/L,793 mg/L and 0.1,respectively,at the granularity of iron and carbon 0.425 mm,pH 3,iron-carbon ratio 3,gas-water ratio 5,HRT 1.5 h,and the removal rates of TN,NH4+-N and NO3--N achieve 51.5%,70% and 50.94%,respectively. 展开更多
关键词 IRON-CARBON MICRO-ELECTROLYSIS NITROGEN NITrate NITROGEN removal efficiency removal rate
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Enhancing toluene removal in a plasma photocatalytic system through a black TiO2 photocatalyst 被引量:4
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作者 Bin ZHU Luyao ZHANG +2 位作者 Yan YAN Meng LI Yimin ZHU 《Plasma Science and Technology》 SCIE EI CAS CSCD 2019年第11期77-85,共9页
An efficient toluene removal in air using a plasma photocatalytic system(PPS) not only needs favorable surface reactions over photocatalysts under the action of plasma,but also requires the photocatalysts to efficie... An efficient toluene removal in air using a plasma photocatalytic system(PPS) not only needs favorable surface reactions over photocatalysts under the action of plasma,but also requires the photocatalysts to efficiently absorb light emitted from the discharge for driving the photocatalytic reactions. We report here that the PPS constructed by integrating a black titania(B-TiO2)photocatalyst with a dielectric barrier discharge(DBD) can effectively remove toluene with above 70% CO2 selectivity and remarkably reduced the concentration of secondary pollutants of ozone and nitrogen oxides at a specific energy input of 1500 J·l-1,while exhibiting good stability. Photocatalyst characterizations suggest that the B-TiO2 provides a high concentration of oxygen vacancies for the surface oxidation of toluene in DBD,and efficiently absorbs ultraviolet–visible light emitted from the discharge to induce plasma photocatalytic oxidation of toluene. The presence of B-TiO2 in the plasma region also results in a high discharge efficiency,facilitating the generation of large numbers of reactive species and thus the oxidation of toluene towards CO2. The greatly enhanced performance of the PPS integrated with B-TiO2 in toluene removal offers a promising approach to efficiently remove refractory volatile organic compounds from air at low temperatures. 展开更多
关键词 PLASMA photocatalysis BLACK TIO2 synergetic effect dielectric barrier discharge toLUENE removal
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Mechanical properties of deep sandstones under loading rate effect 被引量:4
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作者 ZHANG Jun-wen DING Lu-jiang +2 位作者 SONG Zhi-xiang FANWen-bing WANG Shan-yong 《Journal of Central South University》 SCIE EI CAS CSCD 2022年第6期1933-1944,共12页
The advance speed of the working face in coal mines can significantly affect the fluctuation frequency of abutment pressure in front of the coal body.Moreover,it has a certain correlation with the change of axial load... The advance speed of the working face in coal mines can significantly affect the fluctuation frequency of abutment pressure in front of the coal body.Moreover,it has a certain correlation with the change of axial loading rate in coal and rock mechanics test.Therefore,uniaxial compression tests under various loading rates of 0.05,0.1,0.15,0.25,0.5 MPa/s were conducted using 2000 kN triaxial testing machine and PCI-2 acoustic emission test system to study the loading rate effect on the mechanical properties of deep sandstones.The results show that 1)the peak strength and elastic modulus of the deep sandstone increase with the loading rate increasing;2)with the loading rate increasing,the deep sandstone transforms from plastic-elastic-plastic to plastic-elastic and moreover,the failure mode gradually transfers from type I to type III;3)With the loading rate increasing,the total input strain energy,elastic strain energy,and dissipated strain energy generally increase;4)the damage variable presents the evolution characteristics of inverted“S”shape with time,and with the loading rate increasing,the damage degree of the deep sandstone is aggravated.The conclusion obtained can provide the theoretical basis for the stability control of the surrounding rock in deep engineering. 展开更多
关键词 loading rate effect failure mode energy evolution damage evolution mechanical properties deep sandstone
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Undrained vane shear strength of sand-foam mixtures subjected to different shear rates 被引量:3
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作者 Jiazheng Zhong Shuying Wang Tongming Qu 《Journal of Rock Mechanics and Geotechnical Engineering》 SCIE CSCD 2023年第6期1591-1602,共12页
The shear strength of sand-foam mixtures plays a crucial role in ensuring successful earth pressure balance(EPB)shield tunneling.Since the sand-foam mixtures are constantly sheared by the cutterhead and the screw conv... The shear strength of sand-foam mixtures plays a crucial role in ensuring successful earth pressure balance(EPB)shield tunneling.Since the sand-foam mixtures are constantly sheared by the cutterhead and the screw conveyor with varied rotation speeds during tunneling,it is non-trivial to investigate the effect of shear rates on the undrained shear strength of sand-foam mixtures under chamber pressures to extend the understanding on the tunneling process.This study conducted a series of pressurized vane shear tests to investigate the role of shear rates on the peak and residual strengths of sand-foam mixtures at different pore states.Different from the shear-rate characteristics of natural sands or clay,the results showed that the peak strength of sand-foam mixtures under high vertical total stress(σ_(v)≥200 kPa)and low foam injection ratio(FIR30%)decreased with the increase in shear rate.Otherwise,the peak strength was not measurably affected by shear rates.The sand-foam mixtures in the residual state resembled low-viscous fluid with yield stress and the residual strength increased slightly with shear rates.In addition,the peak and residual strengths were approximately linear with vertical effective stress regardless of the total stress and FIR.The peak effective internal friction angle remained almost invariant in a low shear rate(γ′<0.25 s1)but decreased when the shear rate continued increasing.The residual effective internal friction angle was lower than the peak counterpart and insensitive to shear rates.This study unveiled the role of shear rates in the undrained shear strength of sand-foam mixtures with various FIRs and vertical total stresses.The findings can extend the understanding of the rate-dependent shear characteristics of conditioned soils and guide the decision-making of soil conditioning schemes in the EPB shield tunneling practice. 展开更多
关键词 Sand-foam mixture Shear rate Peak and residual strengths Effective stress Effective internal friction angle
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Prediction of proton-induced SEE error rates for the VATA160 ASIC 被引量:1
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作者 Kai Xi Di Jiang +7 位作者 Shan-Shan Gao Jie Kong Hong-Yun Zhao Hai-Bo Yang Tian-Qi Liu Bin Wang Bing Ye Jie Liu 《Nuclear Science and Techniques》 SCIE CAS CSCD 2017年第1期88-93,共6页
We predict proton single event effect(SEE)error rates for the VATA160 ASIC chip on the Dark Matter Particle Explorer(DAMPE) to evaluate its radiation tolerance.Lacking proton test facilities,we built a Monte Carlo sim... We predict proton single event effect(SEE)error rates for the VATA160 ASIC chip on the Dark Matter Particle Explorer(DAMPE) to evaluate its radiation tolerance.Lacking proton test facilities,we built a Monte Carlo simulation tool named PRESTAGE to calculate the proton SEE cross-sections.PRESTAGE is based on the particle transport toolkit Geant4.It adopts a location-dependent strategy to derive the SEE sensitivity of the device from heavy-ion test data,which have been measured at the HI-13 tandem accelerator of the China Institute of Atomic Energy and the heavy-ion research facility in Lanzhou.The AP-8,SOLPRO,and August 1972 worst-case models are used to predict the average and peak proton fluxes on the DAMPE orbit.Calculation results show that the averaged proton SEE error rate for the VATA160 chip is approximately 2.17×10^(-5)/device/day.Worst-case error rates for the Van Allen belts and solar energetic particle events are 1-3 orders of magnitude higher than the averaged error rate. 展开更多
关键词 PROtoN ASIC SINGLE EVENT effects ERROR rates
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Asymmetric Effects on Escape Rates of Bistable System 被引量:2
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作者 王参军 戴祖诚 梅冬成 《Communications in Theoretical Physics》 SCIE CAS CSCD 2011年第12期1041-1044,共4页
The asymmetric effects on the escape rates from the stable states x±in the bistable system are analyzed. The results indicate that the multiplicative noise and the additive noise always enhance the particle escap... The asymmetric effects on the escape rates from the stable states x±in the bistable system are analyzed. The results indicate that the multiplicative noise and the additive noise always enhance the particle escape from stable states x±of bistable.However,the asymmetric parameter r enhances the particle escape from stable state x_+,and holds back the particle escape from stable state x_-. 展开更多
关键词 bistable system escape rate asymmetric effects noise
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Effect of mechanical anisotropy on material removal rate and surface quality during polishing CdZnTe wafers 被引量:1
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作者 LI Yan JIE Wanqi +1 位作者 KANG Renke GAO Hang 《Rare Metals》 SCIE EI CAS CSCD 2011年第4期381-386,共6页
The mechanical characters of CdZnTe crystal were investigated by nanoscratch tests, and the effects of mechanical anisotropy on the material removal rate and surface quality were studied by polishing tests. There is a... The mechanical characters of CdZnTe crystal were investigated by nanoscratch tests, and the effects of mechanical anisotropy on the material removal rate and surface quality were studied by polishing tests. There is a peak of frictional coefficient at the early stage of scratch, and increasing the vertical force will result in the increase of peak value correspondingly. The fluctuation phenomenon of frictional coefficient is generated at high vertical force. The lateral forces show the apparent twofold and threefold symmetries on (110) and (111) planes, respectively. To obtain high surface quality, low polishing pressure and hard direction (〈 T10 〉 directions on (110) plane and 〈 112 〉 directions on (111) plane) should be selected, and to achieve high material removal rate, high polishing pressure and soft direction (〈001〉 directions on (110) plane and 〈 121 〉 directions on (111) plane) should be selected. 展开更多
关键词 cadmium compounds single crystals nanoscratch tests frictional coefficient material removal rate surface quality ANISOTROPY
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Effects of time lag and stress loading rate on permeability in low permeability reservoirs 被引量:4
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作者 WANG Rui YUE Xiang-an +2 位作者 ZHANG Wei TAN Xi-qun ZHANG Yan 《Mining Science and Technology》 EI CAS 2009年第4期526-530,共5页
In order to study the effect of time lag and stress loading rates on rock deformation,the conventional stepped stress loading mode was changed into a continuous mode to investigate the effect of effective pressure on ... In order to study the effect of time lag and stress loading rates on rock deformation,the conventional stepped stress loading mode was changed into a continuous mode to investigate the effect of effective pressure on permeability and porosity.The time lag effect of rock deformation illustrating the relationship between changes in permeability and steady time was studied.Permeability reduction ratios were measured under different stress loading rates which were achieved by different pump rate settings.The results show that permeability and porosity gradually decrease with increases in effective pressure.Permeability at high effective pressure attains stability quickly.Steady times at low effective pressure are very long.Reduction in permeability at lower stress loading rates is small,while,in contrast,it is large at high stress loading rates. 展开更多
关键词 low permeability stress sensitivity time lag effect stress loading rate
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Numerical Derivation of Strain Rate Effects on Material Properties of Masonry with Solid Clay Bricks 被引量:4
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作者 WEI Xueying HAO Hong 《Transactions of Tianjin University》 EI CAS 2006年第B09期147-151,共5页
In this paper, numerical method is used als. A typical unit of masonry is selected to serve merical model of RVE is established with detailed to study the strain rate effect on masonry materias a representative volume... In this paper, numerical method is used als. A typical unit of masonry is selected to serve merical model of RVE is established with detailed to study the strain rate effect on masonry materias a representative volume element (RVE). Nudistinctive modeling of brick and mortar with their respective dynamic material properties obtained from laboratory tests. The behavior of brick and mortar are characterized by a dynamic damage model that accounts for rate-sensitive and pressuredependent properties of masonry materials. Dynamic loads of different loading rates are applied to RVE. The equivalent homogenized uniaxial compressive strength, threshold strain and elastic modulus in three directions of the masonry are derived from the simulated responses of the RVE. The strain rate effect on the masonry material with clay brick and mortar, such as the dynamic increase factor (DIF) of the ultimate strength and elastic modulus as a function of strain rate are derived from the numerical results. 展开更多
关键词 masonry structure strain rate effects dynamic increase factor (DIF) elastic modulus ultimate strength
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