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Identification of secondary organic aerosols based on aerosol mass spectrometry

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中国科学：化学英文版 2010年第12期53卷 2593-2599页

作者： HUANG XiaoFeng 1,ZHAO QianBiao 1,2.HE LingYan 1,HU Min 2.BIAN QiJing 3,XUE Lian 1 & ZHANG YuanHang 2.1 Key Laboratory for Urban Habitat environmental science and {2. School of environment and Energy,peking university Shenzhen Graduate School,Shenzhen 518055,china 2.State Key Joint Laboratory of environmental Simulation and Pollution Control college of environmental sciences and engineering,peking university,{12.,china 3 division of environment,hong kong university of science & technology,hong kong,china 1. Key Laboratory for Urban Habitat environmental science and {2. School of environment and Energy Peking University Shenzhen Graduate School Shenzhen 518055 China2. State Key Joint Laboratory of Environmental Simulation and Pollution Control college of environmental {2. and engineering Peking University Beijing 100871 China3. Division of Environment Hong Kong University of Science & Technology Hong Kong China

Secondary organic aerosol (SOA) is one of the major components of aerosols in the atmosphere and has not been well understood so *** to the complex chemical composition of organic aerosols,the identification of SOA has been a hotspot and difficult issue in the field of aerosol *** study attempts to quantitatively identify SOA in winter of Shenzhen based on positive matrix factorization (PMF) *** sources were resolved and SOA was identified subsequently according to the characteristic ion fragments measured by highly time-resolved aerosol mass spectrometer *** showed that in the winter of Shenzhen the average SOA concentration was 9.41±6.33 g/m 3,accounting for 39.9±2..8% of the total organic *** with primary organic aerosol (POA),the SOA concentrations had no large variation,suggestive of characteristics of regional secondary *** ratio of SOA/BC had pronounced diurnal variation,similar to that of O x (O3+NO2.,indicating SOA formation was significantly controlled by activity of photochemistry in the *** most effective period for SOA formation was from 9 am～3 pm since the SOA/BC ratio increased by 12.% during this *** study provides a new technical method and a new idea for SOA investigation.

关键词： secondary organic aerosol aerosol mass spectrometry positive matrix factorization (PMF)

Evaluation of dry eye disease symptomatology and mental health status among patients with different COVID-19 statuses

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International Journal of Ophthalmology(English edition) 2024年第5期17卷 822-830页

作者： Fang Ruan Wen-Jun kong Qian Fan hong-Wei Dong Wei Zhang Wen-Bin Wei Ying Jie Department of Ophthalmology Beijing You’an HospitalCapital Medical UniversityBeijing Infectious Eye Disease Diagnosis and Treatment CenterBeijing 100069China beijing Tongren Eye Center Beijing Tongren HospitalCapital Medical UniversityBeijing Institute of OphthalmologyBeijing Ophthalmology and Visual Sciences Key LabBeijing 100730China Tianjin Eye Hospital Tianjin Key Lab of Ophthalmology and Visual ScienceTianjin Eye InstituteNankai University Affiliated Eye HospitalNankai University Eye InstituteNankai UniversityClinical College of OphthalmologyTianjin Medical UniversityTianjin 300020China

AIM:To evaluate dry eye disease(DED)symptomatology and mental health status in different COVID-19 ***:A cross-sectional observational design was *** 12. eligible adults(46.34%of men,age range,18-59y)with COVID-19 included in the study from August to November,*** Surface Disease Index(OSDI),Five-item Dry Eye Questionnaire(DEQ-5),Hospital Anxiety and Depression Scale(HADS),and Pittsburgh Sleep Quality Index(PSQI)were used in this ***:OSDI scores were 6.82.1.2.,15.91)in asymptomatic carriers,7.35(2.50,18.38)in mild cases,and 16.67(4.43,2..04)in recurrent cases,with 30.00%,35.56%,and 57.89%,respectively evaluated as having DED symptoms(χ2.7.049,P=0.02.).DEQ-5 score varied from 2.00(0,6.00)in asymptomatic carriers,3.00(0,8.00)in mild cases,and 8.00(5.00,10.00)in recurrent cases,with 2..50%,33.33%,and 55.2.%,respectively assessed as having DED symptoms(χ2.8.532.P=0.014).The prevalence of clinical anxiety(50.00%)and depression(47.37%)symptoms were also significantly higher in patients with recurrent infection(χ2.2..541,P2.30.871,P2.562.95%confidence interval(CI),1.631-7.979;P=0.033]and DEQ-5 scores(odds ratio,3.353;95%CI,1.038-8.834;P=0.043),whereas having a fixed occupation was a protective factor for OSDI scores(odds ratio,0.088;95%CI,0.02.-0.360;P=0.001)and DEQ-5 scores(odds ratio,0.12.;95%CI,0.039-0.405;P=0.001).CONCLUSION:Patients with recurrent COVID-19 have more severe symptoms of DED,anxiety,and depression.

关键词： COVID-19 dry eye disease recurrent infection mental health

Empirical likelihood-based inference in a partially linear model for longitudinal data

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science china Mathematics 2008年第1期51卷 115-130页

作者： XUE LiuGen~(1+) & ZHU LiXing~2.1 college of Applied sciences, {2. university of technology, {2. 10002., china 2.Department of Mathematics, hong kong Baptist university, hong kong, china college of Applied sciences Beijing University of Technology Beijing 100022 China Department of Mathematics Hong Kong Baptist University Hong Kong China

A partially linear model with longitudinal data is considered, empirical likelihood to infer- ence for the regression coefficients and the baseline function is investigated, the empirical log-likelihood ratios is proven to be asymptotically chi-squared, and the corresponding confidence regions for the pa- rameters of interest are then constructed. Also by the empirical likelihood ratio functions, we can obtain the maximum empirical likelihood estimates of the regression coefficients and the baseline function, and prove the asymptotic normality. The numerical results are conducted to compare the performance of the empirical likelihood and the normal approximation-based method, and a real example is analysed.

关键词： partially linear model empirical likelihood confidence region longitudinal data 62.05 62.15 62.2.

Research progress and prospect of low-carbon biological technology for nitrate removal in wastewater treatment

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Frontiers of environmental science & {2. 2024年第7期18卷 1-21页

作者： Ru Zheng Kuo Zhang Lingrui kong Sitong Liu college of environmental {2. and engineering Peking UniversityBeijing 100871China Key Laboratory of Water and Sediment sciences Ministry of Education of ChinaBeijing 100871China Eco-environment and Resource Efficiency Research Laboratory School of Environment and EnergyPeking University Shenzhen Graduate SchoolShenzhen 518055China

Wastewater treatment plants are the major energy consumers and significant sources of greenhouse gas emissions,among which biological nitrogen removal of wastewater is an important contributor to carbon ***,traditional heterotrophic denitrification still has the problems of excessive residual sludge and the requirement of external carbon ***,the development of innovative low-carbon nitrate removal technologies is *** review outlines the key roles of sulfur autotrophic denitrification and hydrogen autotrophic denitrification in low-carbon wastewater *** discovered nitrate/nitrite dependent anaerobic methane oxidation enables sustainable methane emission reduction and nitrogen removal by utilizing available methane in *** microorganisms exhibited a promising potential to achieve carbon-negative nitrate ***,the algal-bacterial symbiosis system and photogranules offer effective and prospective low-carbon options for nitrogen ***,the emerging nitrate removal technology of photoelectrotrophic denitrification and the underlying,photoelectron transfer mechanisms are ***,we summarize and prospect these technologies,highlighting that solar-driven biological nitrogen removal technology is a promising area for future sustainable wastewater *** review has important guiding significance for the design of low-carbon wastewater treatment systems.

关键词： Carbon emissions Low-carbon Biological nitrogen removal Denitrification

The impact of vegetation restoration on erosion-induced sediment yield in the middle Yellow River and management prospect

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science china Earth {2. 2005年第6期48卷 724-741页

作者： CHEN Hao1, ZHOU Jinxing2. CAI Qiangguo1, YUE Zhongqi3, LU Zhongchen4, LIANG Guanglin1& HUANG Jianguo5 1. Key Laboratory of Water Cycle and Related Land Surface Processes, Institute of Geographic {2. and Natural Resources Re-search, Chinese Academy of {2., beijing 100101, china 2. Institute of Forestry, Chinese Academy of Forestry {2., beijing 100091, china 3. Department of Civil engineering, university of hong kong, hong kong, china 4. Eco-environmental Research Center, Chinese Academy of {2., beijing 100085, china 5. college of Resources and environment, Southwest Agricultural university, Chongqing 400716, china Correspondence should be addressed to Chen Hao 1. Key Laboratory of Water Cycle and Related Land Surface Processes Institute of Geographic Sciences and Natural Resources Research Chinese Academy of Sciences 100101 Beijing China 2. Institute of Forestry Chinese Academy of Forestry Sciences 100091 Beijing China 3. Department of Civil engineering University of Hong Kong Hong Kong China 4. Eco-environmental Research Center Chinese Academy of Sciences 100085 Beijing China 5. college of Resources and environment Southwest Agricultural University 400716 Chongqing China

According to the characteristics of water and erosion environments of different natural zones on the Loess Plateau, this paper studies changes of vegetation types, distribution boundaries of forest and grass as well as restoration capacity of vegetation in different natural zones in the middle Yellow River. The annual precipitation of 530 mm is the critical annual pre-cipitation for forest and grass distribution in the middle Yellow River. Among the zonal and azonal environmental factors affecting watershed sediment yield, the intermediate diameter D50 (mm) of suspended load and forest coverage (V, %) play the leading role. Of them the effect weight of forest coverage (V, %) on catchments sediment yield is only 3.4% less than the role of the intermediate diameter (D50, mm), they are almost the same. To effectively control soil erosion in semiarid, especially in hilly-gullied areas and make sediment transport modulus reduce to less than 6000 t/km2. it is rather difficult by merely relying on natural restoration of forest. In the process of cultivated land conversion into forest land and grassland, measures suiting local conditions should be adopted in tree species selection and artificial afforestation (grass planting) based on management with biological measures for slopeland and {2. measures for hilly-gullied areas, so that watershed forest coverage in key counties can reach at least over 30%.Compared with the standard period of precipitation prior to the 1960s, with the decrease of an-nual precipitation at various periods, plant productivities decline to different degrees under natural conditions. The main reason accountable for the low survival rate of new seedlings and grass over years is due to precipitation decrease. In light with regression models of annual pre-cipitation and natural vegetation productivities, it is possible to obtain estimated values of wa-tershed natural vegetation productivity and eco-water consumption needed for the restoration to

关键词： vegetation restoration, eco-water requirement, watershed sediment yield, the middle Yellow River.

Temperature prediction model in multiphase flow considering phase transition in the drilling operations

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Petroleum science 2024年第3期21卷 1969-1979页

作者： Yang Zhang Yong-An Li Xiang-Wei kong Hao Liu Teng-Fei Sun college of Mechanical and Electrical engineering Beijing University of Chemical TechnologyBeijing 100027China School of Petroleum engineering Yangtze UniversityWuhan430000HubeiChina

The study considers gas compression properties,gas slippage,back pressure(BP),phase transition(PT),well depth,and differences in gas-liquid physical properties.A new temperature model for multiphase flow is proposed by considering phase transition in the drilling *** mathematical model of multiphase flow is solved using the finite difference method with annulus mesh division for grid nodes,and a module for multiphase flow calculation and analysis is *** results indicate that the temperature varies along the annulus with the variation of gas influx at the bottom of the *** the process of controlled pressure drilling,as gas slips along the annulus to the wellhead,its volume continuously expands,leading to an increase in the gas content within the annulus,and consequently,an increase in the pressure drop caused by gas *** temperature increases with the increase in BP and decreases in gas influx rate and wellbore *** gas influx,the thermal conductivity coefficient for the gas-drilling mud two phases is significantly weakened,resulting in a considerable change in temperature along the *** the context of MPD,the method of slightly changing the temperature along the annulus by controlling the back pressure is feasible.

关键词： Managed pressure drilling Phase transition Temperature Gas-drilling mud two phase

Effects of genistein, daidzein and glycitein on the osteogenic and adipogenic differentiation of bone marrow stromal cells and on the adipogenic trans-differentiation of osteoblasts

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Progress in Natural science:Materials International 2005年第11期15卷 993-999页

作者： LI Xianghui, ZHANG Jinchao, SUI Senfang and YANG Mengsu (State Key Laboratory of Biomembrane, Department of Biological sciences and Biotechnology, Tsinghua {2., beijing 100084, china Department of Chemistry, college of Chemistry & environmental science, Hebei {2., Baoding 071002. china Department of Biology and Chemistry, City {2. of hong kong, hong kong, china) State Key Laboratory of Biomembrane Department of Biological Sciences and Biotechnology Tsinghua University Beijing 100084 China. Department of Chemistry College of Chemistry & Environmental Science Hebei University Baoding 071002 China. Department of Biology and Chemistry City University of Hong Kong Hong Kong China

The 3-(4,5-dimethylthiazol-2.yl)-2.5-diphenyl tetrazolium bromide (MTT), alkaline phosphatase (ALP) activity and oil red O assays were used to examine the effects of genistein, daidzein and glycitein on the osteogenic and adipogenic differentiation of primary mouse bone marrow stromal cells (MSCs) and the adipogenic trans-differentiation of primary mouse osteoblasts. The results indicated that daidzein, genistein and glycitein at concentrations from 1×10-8 mol/L to 1×10-5mol/L promoted the proliferation of MSCs and osteoblasts; genistein, daidzein and glycitein promoted osteogenic differentiation and inhibited adipogenic differentiation of MSCs, and inhibited adipocytic transdifferentiation of osteoblasts at appropriate concentrations as 17β-estradiol. It suggests that genistein, daidzein and glycitein regulate a dual differentiational process of MSCs into the osteogenic and adipogenic lineages, and trans-differentiational process of primary osteoblasts into the adipocyte lineages, causing a lineage shift toward osteoblast. Protective effects of them on bone may be mediated by a reversal of adipogenesis which may promote the proliferation, differentiation and mineralization of osteoblasts, and make adipocytes secrete less cytokines which may promote osteoclast formation and activation. In addition, the results also indicated that genistein, daidzein and glycitein may be helpful in preventing the development of steroid induced osteonecrosis.

关键词： genistein daidzein glycitein bone marrow stromal cells osteoblasts osteogenic differentiation adipogenic differentiation adipogenic trans-differentiation.

Multiomics analyses of two Leonurus species illuminate leonurine biosynthesis and its evolution

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Molecular Plant 2024年第1期17卷 158-177页

作者： Peng Li Meng-Xiao Yan Pan Liu Dan-Jie Yang Ze-Kun He Yun Gao Yan Jiang Yu kong Xin Zhong Sheng Wu Jun Yang hong-Xia Wang Yan-Bo Huang Le Wang Xiao-Ya Chen Yong-hong Hu Qing Zhao Ping Xu shanghai Key Laboratory of Plant Functional Genomics and Resources Shanghai Chenshan Botanical GardenShanghai Chenshan Plant Science Research CenterChineseAcademy of SciencesShanghaiChina college of Life sciences Shanghai Normal UniversityShanghai 200234China State Key Laboratory of Plant Molecular Genetics CAS Center for Excellence in Molecular Plant SciencesChinese Academy of SciencesShanghaiChina university of the Chinese Academy of sciences Beijing 100049China The Research Center of Chiral Drugs Innovation Research Institute of Traditional Chinese MedicineShanghai University of Traditional Chinese Medicine1200 Cailun RoadShanghai 201203China college of Chemistry and Chemical engineering Shanghai University of Engineering ScienceShanghai 201620China

The Lamiaceae family is renowned for its terpenoid-based medicinal components,but Leonurus,which has traditional medicinal uses,stands out for its alkaloid-rich ***,the principal active compound found in Leonurus,has demonstrated promising effects in reducing blood lipids and treating ***,the biosynthetic pathway of leonurine remains largely ***,we present the chromosome-level genome sequence assemblies of Leonurus japonicus,known for its high leonurine production,and Leonurus sibiricus,characterized by very limited leonurine *** integrating genomics,RNA sequencing,metabolomics,and enzyme activity assay data,we constructed the leonurine biosynthesis pathway and identified the arginine decarboxylase(ADC),uridine diphosphate glucosyltransferase(UGT),and serine carboxypeptidase-like(SCPL)acyltransferase enzymes that catalyze key reactions in this *** analyses revealed that the UGT–SCPL gene cluster evolved by gene duplication in the ancestor of Leonurus and neofunctionalization of SCPL in ***,which contributed to the accumulation of leonurine specifically in ***,our comprehensive study illuminates leonurine biosynthesis and its evolution in Leonurus.

关键词： Lamiaceae Leonurus japonicus Leonurus sibiricus genome sequence alkaloids leonurine gene cluster biosynthetic pathway evolution

Role of gallium wetting layer in high-quality ZnO growth on sapphire (0001) substrates

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science china(Physics,Mechanics & Astronomy) 2004年第5期47卷 612-620页

作者： ZENG Zhaoquan1,3, WANG Yong2. DU Xiaolong1, MEI Zengxia1, kong Xianghe3, JIA Jinfeng1, XUE Qikun1 & ZHANG Ze2. 4 1. State Key Laboratory for Surface Physics, Institute of Physics, Chinese Academy of sciences, {2. 100080, china 2. Laboratory of Electron Microscopy, Institute of Physics, Chinese Academy of sciences, {2. 100080, china 3. college of Physics and engineering, Qufu Normal university, Qufu 2.3165, china 4. {2. university of technology, {2. 10002., china 1. State Key Laboratory for Surface Physics Institute of Physics Chinese Academy of Sciences 100080 Beijing China 2. college of Physics and engineering Qufu Normal University 273165 Qufu China 3. Laboratory of Electron Microscopy Institute of Physics Chinese Academy of Sciences 100080 Beijing China 4. beijing university of {2. 100022 Beijing China

A Ga wetting layer was used to modify the surface structure of sapphire (0001) substrate to prepare high-quality ZnO film by radio frequency plasma-assisted molecule beam epitaxy. We found that this Ga layer plays a crucial role in eliminating 30 rotation domains, controlling polarity and decreasing defect density in ZnO epilayers, as demonstrated by in situ reflection high energy electron diffraction, ex situ high resolution X-ray diffraction and high resolution cross-sectional transmission electron microscopy. Zn-polar film of ZnO was determined by convergent beam electron diffraction. A Ga bilayer model is proposed to understand the effects of the Ga wetting layer on high-quality ZnO growth.

关键词： Ga wetting layer, sapphire, polarity, defect density, zinc oxide, rf-MBE, RHEED, HRXRD, TEM, CBED.