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Effect of Complex Parameters of Porous Media on Desalination Performance in Air-Gap Diffusion Distillation Based on Multiple Regression Analysis

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Journal of Thermal Science 2022年第6期31卷 2329-2345页

作者： CHEN Lele WANG Ping ZHANG Xuan QIU Qinggang Key Laboratory of Ocean Energy Utilization and Energy Conservation of Ministry of Education School of Energy and Power EngineeringDalian University of TechnologyDalian 116024China

Air-Gap Diffusion Distillation(AGDD) is a new technology aiming at solving the problem of the safety of drinking water for residents in remote areas that uses a super hydrophilic porous medium as the hot channel and evaporation surface. In the experiment, it was found that the parameters of porous media have a significant influence on the desalination(evaporation) efficiency of AGDD. Although porous media are widely used as evaporation components, the factors affecting their evaporation efficiency are not fully understood. The evaporation process in super hydrophilic porous media is rarely discussed. A large number of experiments have been carried out based on AGDD. The introduction of statistical methods solves the problem that experiments cannot distinguish the contribution of complex parameters of porous media to evaporation efficiency. Stepwise regression analysis is used to reduce the dimensionality of the independent variables and construct regression equations(coefficient of determination R~2 reached 81.3%-96.8%). Evaporation flux correlations and dimensionless mass transfer correlations are established based on porous media parameters. We found that the surface evaporation of super hydrophilic porous media can be divided into three stages: diffusion evaporation, capillary evaporation, and thermal evaporation. The evaporation efficiency of these three stages is controlled by the vapor diffusion process resistance, capillary force, and energy supply. At low saturation, evaporation efficiency is limited by the resistance of the vapor diffusion process. The evaporation efficiency of the porous media is affected predominantly by the pore size, the specific surface area, porosity and the characteristic length. At high saturation, the evaporation efficiency becomes influenced primarily by the permeability. A small thickness and a high hydrophilicity also improve the evaporation efficiency.

关键词： Air-Gap Diffusion Distillation(AGDD) stepwise regression analysis evaporation super hydrophilic porous media desalination

Comparative analysis between single-train passing and double-train intersection in a tunnel

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JOURNAL OF ZHEJIANG UNIVERSITY-SCIENCE A 2024年第5期25卷 429-442页

作者： Du, Jianming Fang, Qian zhang, xuan Wang, Hualao Minist Transport Bridge & Tunnel Res Ctr Res Inst Highway Beijing 100088 Peoples R China Beijing Jiaotong Univ Tunnel & Underground Engn Res Ctr Minist Educ Beijing 100044 Peoples R China

Aerodynamic pressure significantly impacts the scientific evaluation of tunnel service performance. The aerodynamic pressure of two trains running in a double-track tunnel is considerably more complicated than that of a single train. We used the numerical method to investigate the difference in aerodynamic pressure between a single train and two trains running in a double-track tunnel. First, the numerical method was verified by comparing the results of numerical simulation and on-site monitoring. Then, the characteristics of aerodynamic pressure were studied. Finally, the influence of various train-tunnel factors on the characteristics of aerodynamic pressure was investigated. The results show that the aerodynamic pressure variation can be divided into stage I: irregular pressure fluctuations before the train tail leaves the tunnel exit, and stage II: periodic pressure declines after the train tail leaves the tunnel exit. In addition, the aerodynamic pressure simultaneously jumps positively or drops negatively for a single train or two trains running in double-track tunnel scenarios. The pressure amplitude in the two-train case is higher than that for a single train. The maximum positive peak pressure difference (P-STP) and maximum negative peak pressure difference (P-STN) increase as train speed rises to the power from 2.256 to 2.930 in stage I. The P-STP and P-STN first increase and then decrease with the increase of tunnel length in stage I. The P-STP and P-STN increase as the blockage ratio rises to the power from 2.032 to 2.798 in stages I and II.

关键词： Railway tunnel Aerodynamic effect Pressure characteristic Train speed Tunnel length Blockage ratio HIGH-SPEED TRAIN AERODYNAMIC PRESSURES FIELD-MEASUREMENTS SIMULATION LENGTHS HOOD

Domestic Oral Care Brands Are Regaining Lost Ground

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China Detergent & Cosmetics 2023年第1期8卷 26-28页

作者： ZHANG Xuan 不详

Domestic toothpastes forced to retreat The stories of domestic toothpastes are not as good as soda water. Due to the strength of domestic drinks in recent years, soda water are regaining power. Two Cola brands made other drinks lose grounds in the market. Nowadays, the latest domestic drinks keep emerging and the competition in the market is getting fierce.

关键词： Brand gaining drink

Old fusidane-type antibiotics for new challenges:Chemistry and biology

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Chinese Journal of Natural Medicines 2022年第2期20卷 81-101页

作者： TIAN Chuan WANG Ke ZHANG Xuan LI Gang LOU Hong-Xiang Department of Natural Medicinal Chemistry and Pharmacognosy School of PharmacyQingdao UniversityQingdao 266071China Department of Natural Product Chemistry Key Laboratory of Chemical Biology of Ministry of EducationSchool of Pharmaceutical SciencesShandong UniversityJinan 250012China Shandong Provincial Key Laboratory of Synthetic Biology Key Laboratory of BiofuelsQingdao Institute of Bioenergy and Bioprocess TechnologyChinese Academy of SciencesQingdao 266101China

The spread of antibiotic-resistant bacteria and exhausted drug leads render some infections untreatable now and in the future.To deal with these“new challenges”,scientists tend to re-pick up“old antibiotics”.Fusidane-type antibiotics have been known for nearly 80 years as potent antibacterial agents against gram-positive bacteria,especially Staphylococci,and represent the only triterpene-derived antibiotic class in clinical setting.These attractive characteristics have drawn renewed attention on fusidane-type antibiotics in recent decades.Isolation,characterization,biological evaluation,as well as chemical modifications of fusidane-type antibiotics are increasingly being reported.Combinatorial biosynthesis of this type of antibiotics has been successfully utilized not only for elucidating the biosynthetic pathways,but also for expanding their structural diversity.Some isolated and synthetic compounds exhibit comparable or even more potent biological activity than fusidic acid.This review provides an overview of progress on the studies of structure and biology of fusidane-type antibiotics from 1943 to April 2021.The informative structure-activity relationship is also highlighted.

关键词： Fusidane-type antibiotics Fusidic acid Biosynthesis Structural modification Biological activity

CARs:a new approach for the treatment of autoimmune diseases

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Science China(Life Sciences) 2023年第4期66卷 711-728页

作者： Yeting Sun Yeshuang Yuan Bo zhang xuan zhang Graduate School of Peking Union Medical College Department of RheumatologyBeijing HospitalNational Center of GerontologyInstitute of Geriatric MedicineState Key Laboratory of Complex Severe and Rare DiseasesPeking Union Medical College HospitalChinese Academy of Medical Sciences and Peking Union Medical CollegeBeijing 100730China State Key Laboratory of Complex Severe and Rare Diseases Peking Union Medical College HospitalChinese Academy of Medical SciencesBeijing 100730China Department of Rheumatology Beijing HospitalNational Center of GerontologyInstitute of Geriatric MedicineClinical Immunology CenterChinese Academy of Medical Sciences and Peking Union Medical CollegeBeijing 100730China

The development of chimeric antigen receptor(CAR)-based therapeutic interventions represented a breakthrough in cancer treatment.Following the success of the CAR-T-cell strategy,this novel therapeutic approach has been applied to other diseases,including autoimmune diseases.Using CAR-T cells to deplete pathological immune cells(i.e.,B cells,autoreactive B or T cells,and accessory antigen-presenting cells(APCs))has resulted in favorable outcomes in diseases characterized by excessive autoantibody levels or hyperactive lymphocyte cell numbers.The importance of immunosuppressive regulatory Tcells(Tregs)in restoring immune tolerance has been well established,and CAR-Tregs have shown promising therapeutic potential in treating autoimmune diseases.Moreover,prior experience from the cancer field has provided sufficient paradigms for understanding how to optimize the structure and function of CARs to improve their function,persistence,stability and safety.In this review,we describe the potential application of CAR-T cells and CAR-Tregs in the treatment of autoimmune diseases,and we summarize the currently available strategies of gene editing and synthetic biological tools that have improved the practical application of CAR-based therapies.

关键词： autoimmune diseases chimeric antigen receptor regulatory T cells cellular therapy

Effective implementation and improvement of fast labeled multi-Bernoulli filter

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Journal of Systems Engineering and Electronics 2023年第3期34卷 661-673页

作者： CHENG xuan JI Hongbing zhang Yongquan School of Electronic Engineering Xidian UniversityXi’an 710071China

Effective implementation of the fast labeled multi-Bernoulli(FLMB)filter is addressed for target tracking with interval measurements.Firstly,a sequential Monte Carlo(SMC)implementation of the FLMB filter,SMC-FLMB filter,is derived based on generalized likelihood function weighting.Then,a box particle(BP)implementation of the FLMB filter,BP-FLMB filter,is developed,with a computational complexity reduction of the SMC-FLMB filter.Finally,an improved version of the BP-FLMB filter,improved BP-FLMB(IBP-FLMB)filter,is proposed,improving its estimation accuracy and real-time performance under the conditions of low detection probability and high clutter.Simulation results show that the BP-FLMB filter has a great improvement of the real-time performance than the SMC-FLMB filter,with similar tracking performance.Compared with the BP-FLMB filter,the IBP-FLMB filter has better estimation performance and real-time performance under the conditions of low detection probability and high clutter.

关键词： multi-target tracking interval measurements fast labeled multi-Bernoulli(FLMB)filter sequential Monte Carlo(SMC)implementation box particle(BP)implementation

Optimising multi-vent module-based adaptive ventilation using a novel parameter for improved indoor air quality and health protection

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Building Simulation 2024年第1期17卷 113-130页

作者： Haotian zhang Xiaoxiao Ding Weirong zhang Weijia zhang Yingli xuan Key Laboratory of Green Built Environment and Energy Efficient Technology Beijing University of TechnologyBeijing 100124China Department ofArchitecture TokyoPolytechnic UniversityTokyoJapan

As infectious respiratory diseases are highly transmissible through the air,researchers have improved traditional total volume air distribution systems to reduce infection risk.Multi-vent module-based adaptive ventilation(MAV)is a novel ventilation type that facilitates the switching of inlets and outlets to suit different indoor scenarios without changing ductwork layout.However,little research has evaluated MAV module sizing and air velocity selection,both related to MAV system efficiency in removing contaminants and the corresponding level of protection for occupants in the ventilated room.Therefore,the module-source offset ratio(MSOR)is proposed,based on the MAV module size and its distance from an infected occupant,to inform selection of optimal MAV module parameters.Computational fluid dynamics simulations illustrated contaminant distribution in a two-person MAV equipped office.Discrete phase particles modelled respiratory contaminants from the infected occupant,and contaminant concentration distributions were compared under four MAV air distribution layouts,three air velocities,and three module sizes considered using the MsOR.Results indicate that lower air velocities favour rising contaminant levels,provided the ventilation rate is met.Optimal contaminant discharge can be achieved when the line of outlets is located directly above the infected occupant.Using this parameter to guide MAV system design,85.7% of contaminants may be rendered harmless to the human body within 120 s using the default air vent layout.A more appropriate supply air velocity and air vent layout increases this value to 91.4%.These results are expected to inform the deployment of MAV systems to reduce airborne infection risk.

关键词： multi-vent module-based adaptive ventilation computational fluid dynamics indoor air quality infection control

Microbial self-healing of cracks in cement-based materials and its influencing factors

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Frontiers of Structural and Civil Engineering 2023年第11期17卷 1630-1642页

作者： Xiaoniu YU Qiyong zhang xuan zhang Mian LUO Jiangsu Key Laboratory of Construction Materials Southeast UniversityNanjing 211189China College of Engineering and Technology Southwest UniversityChongqing 400715China School of Civil Engineering and Architecture Jiangsu University of Science and TechnologyZhenjiang 212114China College of Civil Science and Engineering Yangzhou UniversityYangzhou 225127China

Cement-based materials are brittle and crack easily under natural conditions.Cracks can reduce service life because the transport of harmful substances can cause corrosion damage to the structures.This review discusses the feasibility of using microbial self-healing agents for crack healing.Tubular and spherical carriers can be used to load microbial self-healing agents and protect microbes,which prolongs the self-healing time.The area self-healing ratio,permeability,mechanical strength,precipitation depth method,numerical modeling,and ultrasonic method can be employed to identify the self-healing effect of cracks.Moreover,the self-healing mechanism is systematically analyzed.The results showed that microbial self-healing agents can repair cracks in cement-based materials in underground projects and dam gates.The difficulties and future development of self-healing cracks were analyzed.A microbial selfhealing agent was embedded in the cement-based material,which automatically repaired the developing cracks.With the development of intelligent building materials,self-healing cracks have become the focus of attention.

关键词： cement-based materials cracks microbial self-healing agent mechanism intelligent building materials

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本期主题:行政管理体制改革与城乡规划管理

规划师 2014年第4期30卷 5-9页

作者：张璇刘冰洁重庆大学建筑城规学院

改革开放以来，我国的行政管理体制改革不断深入，自党的“十八大”报告中提出继续推动行政管理体制改革后，十八届三中全会通过了《中共中央关于全面深化改革若干重大问题的决定》，标志着我国的行政管理体制改革进入了一个新的时期。... 详细信息

改革开放以来，我国的行政管理体制改革不断深入，自党的“十八大”报告中提出继续推动行政管理体制改革后，十八届三中全会通过了《中共中央关于全面深化改革若干重大问题的决定》，标志着我国的行政管理体制改革进入了一个新的时期。在行政管理体制改革的背景下，城乡规划管理作为城乡规划的重要职能之一，如何应对社会经济发展的需求成为现阶段亟待研究的课题。研究对行政管理体制改革要求进行了梳理，提取与城乡规划管理相关的要点，从简政放权、组织协调和管理监督三个方面提出城乡规划管理应对建议。

关键词：行政管理体制改革城乡规划管理行政放权管理监督

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