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Association between the infection probability of COVID-19 and ventilation rates:An update for SARS-CoV-2 variants

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Building Simulation 2023年第1期16卷 3-12页

作者： Hui Dai bin zhao Departmentof Building Science School of ArchitectureTsinghua UniversityBeijing 100084China Beijing Key Laboratory of Indoor Air Quality Evaluation and Control Tsinghua UniversityBeijing 100084China

Severe acute respiratory syndrome coronavirus 2(SARS-CoV-2),the cause of the current coronavirus disease 2019(COVID-19)pandemic,is ***,the risk of airborne transmission in confined spaces may be higher,and corresponding precautions should be ***,we obtained the quantum generation rate(q)value of three SARS-CoV-2 variants(Alpha,Delta,and Omicron)for the Wells-Riley equation with a reproductive number-based fitted approach and estimated the association between the infection probability and ventilation *** q value was 89–165 h^(−1)for Alpha variant,312–935 h^(−1)for Delta variant,and 725–2,345 h^(−1)for Omicron *** ventilation rates increased to ensure an infection probability of less than 1%,and were 8,000–14,000 m^(3)h^(−1),26,000–80,000 m^(3)h^(−1),and 64,000–250,000 m^(3)h^(−1)per infector for the Alpha,Delta,and Omicron variants,*** the infector and susceptible person wore N95 masks,the required ventilation rates decreased to about 1/100 of the values required without masks,which can be achieved in most typical *** air purifier was ineffective for reducing transmission when used in scenarios without *** prolonged exposure time in confined spaces remains critical in reducing the risk of airborne transmission for highly contagious SARS-CoV-2 variants.

关键词： COVID-19 SARS-CoV-2variants mask ventilation air purifier

A real-time personal PM_(2.5)exposure monitoring system and its application for college students

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Building Simulation 2024年第9期17卷 1531-1539页

作者： Wanning Yang bin zhao Department of Building Science School of ArchitectureTsinghua UniversityBeijing100084China Beijing Key Laboratory of Indoor Air Quality Evaluation and Control Tsinghua UniversityBeijing100084China

There is a growing need in public health to conduct large-scale epidemiological studies to investigate the health effects of fine particulate matter(PM_(2.5))exposure *** response to this need,we developed a real-time personal PM_(2.5)exposure monitoring system(PEPS:Personal Exposure PM_(2.5)System),which is capable of monitoring personal exposure concentration and uploading data in real *** air quality self-labelling device,specifically customized for the PEPS,can be worn on the body and features functions for real-time data automatic upload,data storage,data export,and *** system enables researchers to obtain the big data of personal PM_(2.5)exposure concentration at low cost,with minimal manpower and technical *** has been utilized to investigate the personal exposure levels of PM_(2.5)among college students in Beijing,China,providing a substantial volume of valuable data for indoor air quality and related epidemiological *** maximum difference between the monitored daily average exposure concentration and the outdoor concentration was 265µg/m^(3),corresponding to a relative error of 1579.5%.The correlation analysis of 11 factors showed that the correlation between exposure concentration and outdoor concentration was as high as 0.66(p<0.001),and the correlation between exposure concentration and other certain factors was in the range of[−0.11,−0.03].

关键词： personal exposure monitoring system real-time indoor air quality fine particulate matter

Inverse limits of hereditarily almost expandable class

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Applied Mathematics(A Journal of Chinese Universities) 2009年第2期24卷 237-244页

作者： zhao bin Dept. of Math. Kashgar Teacher＇s College Kashgar 844007 China Dept. of Math. ＆ Informatics Faculty of Science Chiba Univ. Chiba 263 - 8522 Japan

In this paper, the hereditarily almost expandability of inverse limits is investigated, with two results obtained. Let X be the inverse limit space of an inverse system （Xα, π^αβ, ∧}. （1） Suppose X is hereditarily κ-metacompact, if each Xα is hereditarily pointwise collectionwise normal （almost θ-expandable, almost discrete θ-expandable）, then so is X; （2） Suppose X is hereditarily κ-σ-metacompact, if each Xα is hereditarily almost σ-expandable （almost discrete σ-expandable = σ-pointwise collectionwise normal）, then so is X.

关键词： inverse limit space κ-metacompactness κ-σ-metacompactness hereditarily pointwise collection- wise normal hereditarily almost θ-expandable hereditarily almost σ-expandable

Multi-loop adaptive internal model control based on a dynamic partial least squares model

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Journal of Zhejiang University-Science A(Applied Physics & Engineering) 2011年第3期12卷 190-200页

作者： zhao zhao bin HU Jun LIANG State Key Lab of Industrial Control Technology Department of Control Seienee & Engineering Zhejiang University Hangzhou 310027 China

A multi-loop adaptive internal model control (IMC) strategy based on a dynamic partial least squares (PLS) frame-work is proposed to account for plant model errors caused by slow aging,drift in operational conditions,or environmental *** PLS decomposition structure enables multi-loop controller design within latent spaces,a multivariable adaptive control scheme can be converted easily into several independent univariable control loops in the PLS *** each latent subspace,once the model error exceeds a specific threshold,online adaptation rules are implemented separately to correct the plant model mismatch via a recursive least squares (RLS) *** the IMC extracts the inverse of the minimum part of the internal model as its structure,the IMC controller is self-tuned by explicitly updating the parameters,which are parts of the internal *** parameter convergence and system stability are briefly analyzed,and proved to be ***,the proposed control scheme is tested and evaluated using a widely-used benchmark of a multi-input multi-output (MIMO) system with pure delay.

关键词： Partial least squares (PLS) Adaptive internal model control (IMC) Recursive least squares (RLS)

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L-quantum spaces

Science China(Information Sciences) 2016年第3期59卷 153-161页

作者： bin zhao Nana MA College of Mathematics and Information Science Shaanxi Normal University

In this paper, based on a complete residuated lattice L, we introduce the definitions of L-quantum spaces and continuous mappings. Then we establish an adjunction between the category of stratified L-quantum spaces and the opposite category of two-sided L-quantales. We also prove that the category of sober L-quantum spaces is dually equivalent to the category of spatial two-sided L-quantales.

关键词： L-quantum space L-quantale adjunction stratified L-quantum space spatial two-sided L quantale

Experiments and calculations of wave breaking and evolution of wave groups with high steepness

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Journal of Hydrodynamics 2022年第5期34卷 975-980页

作者： Wen-yang Duan Kun Zheng bin-bin zhao College of Shipbuilding Engineering Harbin Engineering UniversityHarbin150001China

The evolution of the nonlinear wave groups in deep water is investigated through laboratory measurements and numerical *** experiments are conducted in deep-water wave tank,focusing on the characteristics of breaking waves arising from the evolved wave *** quantitative results are obtained for the significant breaking wave train,including the surface elevation time series,the local geometry,and the energy dissipation.A nonlinear model for the evolution of the wave groups in deep water is developed by adding eddy viscosity dissipation terms in the High Level Irrotational Green-Naghdi(HLIGN)*** results of the simulation are compared with the laboratory measurements,and good agreement is observed for the evolved wave train.

关键词： Wave group evolution wave breaking High-Level Irrotational Green-Naghdi(HLIGN)equations laboratory experiments

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生物3D打印仿生支架促进肩袖损伤后的愈合

中国组织工程研究 2025年第22期29卷 4761-4770页

作者：徐杰酒精卫刘海峰赵斌山西医科大学第二医院骨科山西省太原市030000 骨与软组织损伤修复山西省重点实验室山西省太原市030000

背景:大多数肩袖损伤发生于冈上肌腱,由于肌腱组织缺少血管以及肩袖复杂的解剖结构,临床治疗效果非常有限。组织工程技术和干细胞生物学的快速发展为提高肌腱修复质量带来了新的希望。目的:通过生物3D打印技术制备人脐带间充质干细胞/... 详细信息

背景:大多数肩袖损伤发生于冈上肌腱,由于肌腱组织缺少血管以及肩袖复杂的解剖结构,临床治疗效果非常有限。组织工程技术和干细胞生物学的快速发展为提高肌腱修复质量带来了新的希望。目的:通过生物3D打印技术制备人脐带间充质干细胞/甲基丙烯酸酐化明胶复合支架,观察该支架修复肩袖损伤的效果。方法:(1)体外细胞实验:制备明胶微载体,将人脐带间充质干细胞接种于明胶微载体表面构建组织工程化干细胞。制备甲基丙烯酸酐化明胶水凝胶打印墨水,使用甲基丙烯酸酐化明胶水凝胶打印墨水重悬组织工程化干细胞,放入3D打印机的生物墨水容器中进行打印,蓝光照射固化5 min后即得人脐带间充质干细胞/甲基丙烯酸酐化明胶复合支架。通过死活染色、CCK-8实验检测支架内人脐带间充质干细胞的活性。(2)动物体内实验:采用随机区组设计方法将24只SD大鼠随机4组,每组6只:正常组不进行任何处理,肩袖损伤组、单纯支架组、细胞支架组建立冈上肌腱撕裂的肩袖损伤模型,单纯支架组、细胞支架组造模后分别将甲基丙烯酸酐化明胶支架、人脐带间充质干细胞/甲基丙烯酸酐化明胶复合支架植入肌腱损伤处。术后4周,分别进行大鼠行为学测试及肩袖冈上肌腱组织学病理组织形态观察。结果与结论:(1)体外细胞实验:死活染色结果显示,明胶微载体可减轻3D打印过程对人脐带间充质干细胞造成的损伤,随着培养时间的延长,支架内的人脐带间充质干细胞存活率升高;CCK-8实验结果显示,随着培养时间的延长,支架内的人脐带间充质干细胞活性无明显变化。(2)动物体内实验:行为学测试结果显示,相较于肩袖损伤组、单纯支架组,细胞支架组大鼠四肢运动功能明显改善;肩袖冈上肌腱苏木精-伊红与Masson染色结果显示,相较于肩袖损伤组、单纯支架组,细胞支架组肌纤维排列较规律,无明显的炎性细胞浸润,胶原容积百分比降低;免疫荧光染色结果显示,相较于肩袖损伤组、单纯支架组,细胞支架组肩袖冈上肌腱内白细胞介素6、肿瘤坏死因子α蛋白表达明显降低。(3)结果表明,生物3D打印的人脐带间充质干细胞/甲基丙烯酸酐化明胶复合支架可促进肩袖损伤组织修复再生。

关键词：肩袖损伤冈上肌腱损伤人脐带间充质干细胞细胞治疗组织工程化干细胞生物支架甲基丙烯酸化明胶生物3D打印

A Novel Framework for Lim-inf Convergence in Posets

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Acta Mathematica Sinica,English Series 2022年第5期38卷 953-962页

作者： bin zhao Jing LU School of Mathematics and Statistics Shaanxi Normal UniversityXi'an 710119P.R.China

In this paper,we give a novel framework for lim-inf convergence in posets through the concept of T_(0) enriched closure *** precisely,we define and study Enr-convergence in T_(0) enriched closure ***,we give a suffici... 详细信息

关键词： Closure opeartor lim-inf convergence Enr-convergence enriched continuous space

Numerical evaluation of tandem rotor for highly loaded transonic fan

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航空动力学报 2011年第6期26卷 1352-1361页

作者： zhao bin LIU Bao-jie School of Jet Propulsion Beijing University of Aeronautics and Astronautics Beijing 100191 China

Transonic tandem rotor was designed for highly loaded fan at a corrected tip speed of 381 m/s and another conventional rotor was designed as a baseline to evaluate the loading superiority of tandem rotor with three-dimensional(3-D) numerical *** aft blade solidity and its impact on total loading level were studied in *** result indicates that tandem rotor has potential to achieve higher loading level and attain favorable aerodynamic performance in a wide range of loading coefficient 0.55~0.68,comparing with the conventional rotor which produced a total pressure ratio of 2.0 and loading coefficient of 0.42.

关键词： transonic fan tandem rotor highly loaded loading coefficient numerical simulation