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Bursting behaviours in cascaded stimulated Brillouin scattering

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Chinese Physics B 2012年第1期21卷 310-313页

作者： Liu Zhan-Jun He Xian-Tu zheng chun-yang Wang Yu-Gang Institute of Applied Physics and Computational Mathematics Beijing 100094China State Key Laboratory of Nuclear Physics and Technology Center for Applied Physics and TechnologyPeking UniversityBeijing 100871China

Stimulated Brillouin scattering is studied by numerically solving the Vlasov Maxwell system. A cascade of stim- ulated Brillouin scattering can occur when a linearly polarized laser pulse propagates in a plasma. It is found that a stimulated Brillouin scattering cascade can reduce the scattering and increase the transmission of light, as well as intro- duce a bursting behaviour in the evolution of the laser-plasma interaction. The bursting time in the reflectivity is found to be less than half the ion acoustic period. The ion temperature can affect the stimulated Brillouin scattering cascade, which can repeat several times at low ion temperatures and can be completely eliminated at high ion temperatures. For stimulated Brillouin scattering saturation, higher-harmonic generation and wave wave interaction of the excited ion acoustic waves can restrict the amplitude of the latter. In addition, stimulated Brillouin scattering cascade can restrict. the amplitude of the scattered light.

关键词： bursting behaviour stimulated Brillouin scattering cascade

木瓜蛋白酶天然抑制剂筛选及在护肤品中的应用研究

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日用化学品科学 2024年第8期47卷 29-35页

作者：李磊马文君王培培郑春阳天津强微特生物科技有限公司天津300384 守正创新生物科技(天津)有限公司天津300384

选取化妆品常用的22种活性原料,分别利用紫外分光光度计法和SDS-PAGE法进行体外抑制木瓜蛋白酶活性实验;利用Franz扩散池和人体功效测试检验纤连蛋白透皮过程与抗皱功效,间接证明对木瓜蛋白酶的抑制效果。结果表明,金缕梅提取物抑制酶... 详细信息

选取化妆品常用的22种活性原料,分别利用紫外分光光度计法和SDS-PAGE法进行体外抑制木瓜蛋白酶活性实验;利用Franz扩散池和人体功效测试检验纤连蛋白透皮过程与抗皱功效,间接证明对木瓜蛋白酶的抑制效果。结果表明,金缕梅提取物抑制酶解反应获得的纤连蛋白浓度最高,其他依次为无患子提取物、海茴香提取物、燕麦提取物、高山火绒草提取物、卡瓦胡椒提取物,对纤连蛋白的透皮与改善眼角皱纹有显著性差异。

关键词：木瓜蛋白酶金缕梅提取物纤连蛋白抗皱

Technology Development for Controlling Slab Transverse Corner Crack of Typical Micro-alloyed Steels

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Journal of Iron and Steel Research International 2015年第2期22卷 99-105页

作者： Hui ZHANG chun-zheng yang Ming-lin WANG Hong-biao TAO He-ping LIU Xue-bing WANG Central Iron and Steel Research Institute Shougang Jingtang United Iron and Steel Co. Ltd.

A mathematical model for simulating the fluid flow, heat transfer and solidification in the conventional mold and the chamfer mold, together with a finite element stress-strain model in the straightening process of both molds, were established for the typical niobium, vanadium, and titanium micro-alloyed steels. On the basis of both numerical analysis, the mold copper plate with an optimum chamfered shape was designed and applied in industrial tests. The predicted results from numerical simulation of fluid flow, heat transfer and solidification in the conven tional mold and the chamfer mold show that the increased chamfered angle leads to an approximately linear increase o[ the slab surface temperature, but it also causes strong flow near the slab corner. Very small chamfered length can lead to a significant increase of the temperature near the slab corner. However, with further increasing the chamfered length, the temperature of the slab corner increased slightly. The calculated results from the finite element analysis of stress-strain during the straightening process show that at the same slope width, the tangential strain on the slat） edges and corners is minimum when the chamfered angle is 30° and 45°, which is only 40° to 46° of rectangular slabs with the same cross-section area. At the same chamfered angle of 30°, when the chamfered length is controlled between 65-85 mm, the tangential strain on the part of the slab edges and corners is relatively smaller. Industrial test results show that the slab corner temperature at straightening segment increases about 100 ℃ by using chamfer mold compared to the conventional molds. The slab transverse corner cracks have been reduced more than 95° in comparison with those in the conventional mold.

关键词： micro-alloyed steel transverse corner crack chamfer mold slab

The role of innate immunity in diabetic nephropathy and their therapeutic consequences

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Journal of Pharmaceutical Analysis 2024年第1期14卷 39-51页

作者： Min yang chun Zhang Department of Nephrology Union HospitalTongji Medical CollegeHuazhong University of Science and TechnologyWuhan430022China

Diabetic nephropathy (DN) is an enduring condition that leads to inflammation and affects a substantial number of individuals with diabetes worldwide. A gradual reduction in glomerular filtration and emergence of proteins in the urine are typical aspects of DN, ultimately resulting in renal failure. Mounting evidence suggests that immunological and inflammatory factors are crucial for the development of DN. Therefore, the activation of innate immunity by resident renal and immune cells is critical for initiating and perpetuating inflammation. Toll-like receptors (TLRs) are an important group of receptors that identify patterns and activate immune responses and inflammation. Meanwhile, inflammatory responses in the liver, pancreatic islets, and kidneys involve inflammasomes and chemokines that generate pro-inflammatory cytokines. Moreover, the activation of the complement cascade can be triggered by glycated proteins. This review highlights recent findings elucidating how the innate immune system contributes to tissue fibrosis and organ dysfunction, ultimately leading to renal failure. This review also discusses innovative approaches that can be utilized to modulate the innate immune responses in DN for therapeutic purposes.

关键词： Innate immunity Diabetic nephropathy Inflammation Toll-like receptor Inflammasomes

One-step conversion of methane and formaldehyde to ethanol over SA-FLP dual-active-site catalysts: A DFT study

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Chinese Chemical Letters 2024年第4期35卷 544-548页

作者： Tao Ban Xi-yang Yu Hai-Kuo Tian zheng-Qing Huang chun-Ran Chang Shaanxi Key Laboratory of Energy Chemical Process Intensification School of Chemical Engineering and TechnologyXi'an Jiaotong UniversityXi'an 710049China Shaanxi Key Laboratory of Low Metamorphic Coal Clean Utilization School of Chemistry and Chemical EngineeringYulin UniversityYulin 719000China

One-step conversion of methane and formaldehyde into ethanol is a 100% atom-efficient process for carbon resources utilization and environment protection but still faces eminent challenges due to the lacking of efficient catalysts. Therefore, developing active and stable catalysts is crucial for the co-conversion of methane and formaldehyde. Herein, twelve kinds of “Single-Atom”-“Frustrated Lewis Pair”(SA-FLP)dual-active-site catalysts are designed for the direct conversion of methane and formaldehyde to ethanol based on density functional theory(DFT) calculations and microkinetic simulations. The results show that the SA-FLP dual active sites can simultaneously activate methane at the SA site and activate formaldehyde at the FLP site. Among the twelve designed SA-FLP catalysts, Fe1-FLP shows the best performance in the co-conversion of methane and formaldehyde to ethanol with the rate-determining barrier of 1.15 e *** is proved as the main product with the turnover frequency of 1.32 × 10^(-4)s^(-1)at 573 K and 3 *** work provides a universal strategy to design dual active sites on metal oxide materials and offers new insights into the effective conversion of methane and formaldehyde to desired C_(2) chemicals.

关键词： Single-atom Frustrated Lewis pairs Methane conversion Dual active sites Ethanol synthesis

Ellagic acid inhibits gastric cancer cells by modulating oxidative stress and inducing apoptosis

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Asian Pacific Journal of Tropical Biomedicine 2024年第4期14卷 162-169页

作者： Jian zheng chun-Feng Li Department of Diagnostic Radiology Division Harbin Medical University Cancer HospitalHeilongjiangChina Department of Gastrointestinal Surgical Ward Harbin Medical University Cancer HospitalHeilongjiangChina

Objective:To evaluate the anticancer effect of ellagic acid on gastric cancer ***:MTT assay was used to evaluate the effect of ellagic acid at different concentrations(0.5-100μg/mL)on gastric cancer AGS ***-qPCR and Western blot analyses were applied to assess apoptosis(BCL-2,CASP-3,and BAX)and autophagy(LC3,ATG5,and BECN1)in AGS cells treated with ellagic *** expression of invasion-related markers including TP53,CDKN2A,and PTEN was *** addition,cell cycle markers including cyclin A,B,D,and E were measured by *** stress markers were evaluated using ***:Ellagic acid inhibited the proliferation of AGS cells in a concentration-and time-dependent *** expression of BCL-2 was significantly decreased(P0.05).Moreover,the oxidative stress markers including SOD,TAC,and MDA were increased by ellagic acid(P<0.01).Conclusions:Ellagic acid can inhibit cell proliferation,induce apoptosis,and modulate oxidative stress in AGS ***,further in vivo and molecular studies are needed to verify its anticancer efficacy.

关键词： Ellagic acid Gastric cancer Apoptosis Autophagy Metastasis Proliferation

Fluid-solid coupling numerical simulation of micro-disturbance grouting treatment for excessive deformation of shield tunnel

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Underground Space 2024年第6期19卷 87-100页

作者： Yanjie Zhang zheng Cao chun Liu Hongwei Huang College of Civil Engineering and Architecture Henan University of TechnologyZhengzhou 450001China School of Earth Sciences and Engineering Nanjing UniversityNanjing 210023China Key Laboratory of Geotechnical and Underground Engineering of Ministry of Education Tongji UniversityShanghai 200092China Department of Geotechnical Engineering College of Civil EngineeringTongji UniversityShanghai 200092China

Micro-disturbance grouting is a recovery technique to reduce the excessive deformation of operational shield tunnels in urban *** grout mass behaves as a fluid in the ground before hardening to form a grout–soil mixture,which highlights the necessity of using fluid–solid coupling method in the simulation of grouting *** a discrete element modeling environment,this paper proposes a novel fluid-solid coupling method based on the pore density flow *** demonstrate the effectiveness of this method,it is applied to numerical simulation of micro-disturbance grouting process for treatment of large transverse deformation of a shield tunnel in Shanghai Metro,*** simulation results reveal the mechanism of recovering tunnel convergence by micro-disturbance grouting in terms of compaction and fracture of soil,energy analysis during grouting,and mechanical response of soil-tunnel interaction ***,the influence of the three main grouting parameters(i.e.,grouting pressure,grouting distance,and grouting height)on tunnel deformation recovery efficiency is evaluated through parametric *** order to efficiently recover large transverse deformation of shield tunnel in Shanghai Metro,it is suggested that the grouting pressure should be about 0.55 MPa,the grouting height should be in the range of 6.2–7.0 m,and the grouting distance should be in the range of 3.0–3.6 *** results provide a valuable reference for grouting treatment projects of over-deformed shield tunnel in soft soil areas.

关键词： Fluid-solid coupling Discrete element method Pore density flow Micro-disturbance grouting Soil-tunnel interaction

Magnitude and direction of temperature variability affect hospitalization for myocardial infarction and stroke:population-based evidence from Guangzhou,China

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Frontiers of Environmental Science & Engineering 2024年第3期18卷 1-11页

作者： Zhou yang Murui zheng Ze-Lin Yan Hui Liu Xiangyi Liu Jie-Qi Jin Jiagang Wu chun-Quan Ou State Key Laboratory of Organ Failure Research Department of BiostatisticsGuangdong Provincial Key Laboratory of Tropical Disease ResearchSchool of Public HealthSouthern Medical UniversityGuangzhou 510515China Guangzhou Center for Disease Control and Prevention Guangzhou 510440China

Relationships between nonoptimal temperatures and cardiovascular disease(CVD)mortality have been well ***,evidence of the association between temperature variability(TV)and CVD morbidity is *** study aimed to quantify the risk and burden of CVD-related hospitalization associated with the magnitude and direction of *** on meteorology and population-based hospitalizations for myocardial infarction(MI)and stroke were collected in Guangzhou,China,from 2013 to *** temperature variability(HTV)was measured as the standard deviation of hourly temperature records over specific exposure *** direction(upward or downward)of HTV was defined as the average daily mean temperature change relative to that of the previous day during the exposure ***-Poisson regression was applied to assess the impact of HTV after adjusting for the daily mean temperature,and the hospitalization fractions attributable to HTV were calculated.A 1℃-increase in HTV was significantly associated with a 2.24%and 1.72%increase in hospitalizations for MI and hemorrhagic stroke(HS)at lag 0–1 d,respectively,and a 1.55%increase in hospitalizations for ischemic stroke(IS)at lag 0–3 *** the study period,5.99%,4.64%,and 4.53%of MI,HS,and IS hospitalizations,respectively,were attributable to *** upward TV exerts acute effects on CVD hospital admissions,whereas the impact of downward TV generally *** findings highlight the importance of the magnitude and direction of temperature fluctuations,in addition to the mean level,in assessing the adverse health impacts of temperature variations.

关键词： Hourly temperature variability Cardiovascular Hospitalization Direction China

Solid-conversion synthesis of three-dimensionally ordered mesoporous ZSM-5 catalysts for the methanol-to-propylene reaction

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Frontiers of Chemical Science and Engineering 2024年第8期18卷 111-122页

作者： Weilong chun Chenbiao yang Xu Wang Xin yang Huiyong Chen School of Chemical Engineering Northwest UniversityXi’an 710069China International Science&Technology Cooperation Base for Clean Utilization of Hydrocarbon Resources Chemical Engineering Research Center of the Ministry of Education for Advanced Use Technology of Shanbei EnergyCollaborative Innovation Center for Development of Energy and Chemical Industry in Northern ShaanxiNorthwest UniversityXi’an 710069China

A facile synthesis of hierarchical ZSM-5 with the three-dimensionally ordered mesoporosity(3DOm ZSM-5)was achieved by solid conversion(SC)of SiO_(2)colloidal crystals to high-crystalline *** products of 3DZ5_S/C and 3DZ5_S,which were severally transformed from the carbon-padded SiO_(2)colloidal crystals and the initial SiO_(2)colloidal crystals,exhibited not only a similar ordered structure and acidity but also higher crystallinity and more balanced meso-/micropore combination in comparison with 3DZ5_C obtained by the conventional confined space crystallization *** three synthesized 3DZ5 catalysts showed improved methanol-to-propylene performance than the commercially microporous ZSM-5(CZ5),embodied in five times longer lifetime,higher propylene selectivity and S_(propylene)/S_(ethylene) ratio(P/E),and superior coke toleration with lower formation rate of coke(R_(coke)).Moreover,the 3DZ5_S catalyst in situ converted from SiO_(2)colloidal crystals presented the highest selectivities of propylene(42.51%)and light olefins(74.6%)among all three 3DZ5 *** high efficiency in synthesis and in situ utilization of SiO_(2)colloidal crystals demonstrate the proposed SC strategy to be more efficiently and eco-friendly for the high-yield production of not only 3DOm ZSM-5 but also other types of hierarchical zeolites.

关键词： hierarchical zeolite three-dimensionally ordered mesoporosity ZSM-5 solid conversion methanol-to-propylene