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Source profiles of particulate organic matters emitted from cereal straw burnings

Journal of Environmental Sciences 2007年第2期19卷 167-175页

作者： zhang yuan-xun SHAO Min zhang yuan-hang ZENG Li-min HE Ling-yan ZHU Bin WEI Yong-jie ZHU Xian-lei State Key Joint Laboratory of Environmental Simulation and Pollution Control College of Environmental Sciences Peking University Beijing 100871 China Shenzhen Graduate School Peking University Shenzhen 518055 China

Cereal straw is one of the most abundant biomass burned in China but its contribution to fine particulates is not adequately understood. In this study, three main kinds of cereal straws were collected from five grain producing areas in China. Fine particulate matters （PMzs） from the cereal straws subjected to control burnings, both under smoldering and flaming status, were sampled by using a custom made dilution chamber and sampling system in the laboratory. Element carbon （EC） and organic carbon （OC） was analyzed. 141 compounds of organic matters were measured by gas chromatography-mass spectrum （GC-MS）. Source profiles of particulate organic matters emitted from cereal straw burnings were obtained. The results indicated that organic matters contribute a large fraction in fine particulate matters. Levoglucosan had the highest contributions with averagely 4.5% in mass of fine particulates and can be considered as the tracer of biomass burnings. Methyloxylated phenols from lignin degradation also had high concentrations in PM2.5, and contained approximately equal amounts of guaiacyl and syringyl compounds. 13-Sitostrol also made up relatively a large fraction of PMz5 compared with the other sterols （0.18%-0.63% of the total fine particle mass）. Normal alkanes, PAHs, fatty acids, as well as normal alkanols had relatively lower concentrations compared with the compounds mentioned above. Carbon preference index （CPI） of normal alkanes and alkanoic acids showed characteristics of biogenic fuel burnings. Burning status significantly influenced the formations of EC and PAHs. The differences between the emission profiles of straw and wood combustions were displayed by the fingerprint compounds, which may be used to identify the contributions between wood and straw burnings in source apportionment researches.

关键词： biomass burning cereal straw particulate organic matter source profile

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Quantitative relationship between visibility and mass concentration of PM2.5 in Beijing

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Journal of Environmental Sciences 2006年第3期18卷 475-481页

作者： WANG Jing-li zhang yuan-hang SHAO Min LIU Xu-lin ZENG Li-min CHENG Cong-lan XU Xiao-feng Institute of Urban Meteorology China Meteorological Administration Beijing 100089 China State Joint Key Laboratory of Environmental Simulation and Pollution Control College of Environmental Sciences Peking University Beijing 100871 China Beijing Meteorological Information and Network Center Beijing 100089 China

The pollution of particulate matter less than 2.5μm （PM2.5） is a serious environmental problem in Beijing. The annual average concentration of PM2.5 in 2001 from seasonal monitor results was more than 6 times that of the U,S, national ambient air quality standards proposed by U.S. EPA. The major contributors to mass of PM2.5 were organics, crustal elements and sulfate. The chemical composition of PM2.5 varied largely with season, but was similar at different monitor stations in the same season. The fine particles （PM2.5） cause atmospheric visibility deterioration through light extinction, The mass concentrations of PM2.5 were anti-correlated to the visibility, the best fits between atmospheric visibility and the mass concentrations of PM2.5 were somehow different： power in spring, exponential in summer, logarithmic in autumn, power or exponential in winter. As in each season the meteorological parameters such as air temperature and relative humidity change from day to day, probably the reason of above correlations between PM2.5 and visibility obtained at different seasons come from the differences in chemical compositions of PM2.5.

关键词： PM2.5 atmospheric urban aerosol air pollution meteorological factor visibility

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Preparation, Crystallization and Mechanical Properties of Potassium Aluminosilicate Glass-ceramics

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Journal of Wuhan University of Technology(Materials Science) 2024年第3期39卷 587-595页

作者：郑伟宏黄猛 GAO Zipeng zhang hang yuan Jian TIAN Peijing PENG Zhigang State Key Laboratory of Silicate Materials for Architectures Wuhan University of TechnologyWuhan 430070China Shahe Research Institute of Glass Technology Shahe 054100China

In this study,transparent K_(2)O-Al_(2)O_(3)-SiO_(2)(KAS)glass-ceramics with leucite as the main crystalline phase were prepared by melting-quench method and two-step heat treatment.The effects of SiO_(2)/Al_(2)O_(3) ratio and heat treatment on crystallization and mechanical properties were studied.The crystallization kinetics and X-Ray Diffraction(XRD)results showed that SiO_(2)/Al_(2)O_(3) ratio and heat treatment system had a direct impact on the crystallization behavior of potassium aluminosilicate glass-ceramics.When heat-treated at 680℃/2 h and 780℃/1 h,cracks generated on the surface of the sample with the addition of SiO_(2)/Al_(2)O_(3)=4.8(in mol)due to the huge difference in the coefficient of thermal expansion between glass matrix and surface.When the addition of SiO_(2)/Al_(2)O_(3)(in mol)was 4,the sample with leucite as the main crystalline phase showed an excellent fracture toughness(1.46 MPa·m^(0.5))after the heat treatment of 680℃/2 h and 780℃/5 h.And there was a phase transformation from kaliophilite to leucite.The crystalline phases of the sample heat-treated at 680℃/8 h and 780℃/1 h were leucite and kaliophilite,which resulted in the visible light transmittance of 63%and the fracture toughness of 0.91 MPa·m^(0.5).Furthermore,after the heat treatment of 680℃/2 h and 780℃/5 h,the main crystalline phase of the sample with SiO_(2)/Al_(2)O_(3)=3.2(in mol)was still kaliophilite.Because leucite only grows on the surface of the sample and is hard to grow inward,it is hard to achieve the bulk crystallization of leucite in the sample with SiO_(2)/Al_(2)O_(3)=3.2(in mol).

关键词： leucite glass-ceramic kaliophilite crystallization kinetics

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Intraspecific floral colour variation in three Pedicularis species

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Plant Diversity 2024年第2期46卷 274-279页

作者： Qiu-Yu zhang Zhe Chen hang Sun Yang Niu State Key Laboratory of Plant Diversity and Specialty Crops Kunming Institute of BotanyChinese Academy of SciencesKunming 650201YunnanChina University of Chinese Academy of Sciences Beijing 100049China

Flower constancy describes the phenomenon that pollinators tend to successively visit flowers of a single species during foraging,reducing reproductive interference in natural communities.The extent of flower constancy is largely determined by the floral traits of co-flowering species.Both higher inter-specific and lower intraspecific differences of floral traits should contribute to a higher level of flower constancy.However,previous studies mainly focused on interspecific difference,and the intraspecific variation(consistency)of floral traits received much less attention.We hypothesise that selection may favour lower intraspecific floral trait variation in communities composed of multiple co-flowering congeners.We investigated the floral colour variation of three focal Pedicularis species that share pollinators in 19communities composed of either single or multiple Pedicularis species.Colour was quantified using image-based colour analysis as perceived by pollinators.We found that most of the intrapopulation floral colour variation was below the colour discrimination threshold of bumblebees,implying strongly constrained by the visual selection by pollinators.Contrary to the hypothesis,there is no significant difference in intraspecific floral colour variation between different community contexts.It may be due to the relatively large interspecific floral colour differences of most co-flowering species.The influence of community context on intraspecific variation may be reflected in floral traits other than colours.

关键词： Flower constancy Floral colour variation Plantepollinator interactions Pollinator vision

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Unveiling the Contribution of Lactic Acid to the Passivation Behavior of Ti-6Al-4V Fabricated by Laser Powder Bed Fusion in Hank’s Solution

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Acta Metallurgica Sinica(English Letters) 2024年第1期37卷 102-118页

作者： Yu-hang Chu Liang-Yu Chen Bo-yuan Qin Wenbin Gao Fanmin Shang Hong-Yu Yang Lina zhang Peng Qin Lai-Chang zhang School of Materials Science and Engineering Jiangsu University of Science and TechnologyZhenjiang212100China Foshan(Southern China)Institute for New Materials Foshan528200China Key Laboratory of Automobile Materials Ministry of Education and Department of Materials Science and EngineeringJilin UniversityChangchun130025China Centre for Advanced Materials and Manufacturing School of EngineeringEdith Cowan University270 Joondalup DriveJoondalupPerthWA6027Australia

In actual physiological environments,bacteria can activate the immune system and release lactic acid.However,the detailed contribution of lactic acid to the passivation behavior of titanium(Ti)alloys is still unclear.The current work investigated the in vitro passivation behavior of Ti-6Al-4V(TC4)alloys fabricated by laser powder bed fusion in Hank's solution with and without adding lactic acid.Electrochemical methods,inductively coupled plasma atomic emission spectrometer,and X-ray photoelectron spectroscopy were jointly used.Adding lactic acid decreases the corrosion resistance of samples by degrading the formed passive film.The film formed in the(lactic acid)-containing solution exhibits a higher level of oxygen vacancies and a lower thickness,attributed to the suppressed formation of Ti^(4+)transformed from Ti^(3+)and Ti^(2+).Moreover,the presence of lactic acid would increase the open circuit potential,relieve the ions release,and hinder the deposition of calcium phosphates within 24 h immersion.

关键词： Titanium alloy Corrosion behavior Passive film Lactic acid Laser powder bed fusion

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The transcriptional control of LcIDL1–LcHSL2 complex by LcARF5 integrates auxin and ethylene signaling for litchi fruitlet abscission

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Journal of Integrative Plant Biology 2024年第6期66卷 1206-1226页

作者： Xingshuai Ma Zidi He Ye yuan Zhijian Liang hang zhang Vilde Olsson Lalun Zhuoyi Liu Yanqing zhang Zhiqiang Huang Yulian Huang Jianguo Li Minglei Zhao State Key Laboratory for Conservation and Utilization of Subtropical Agro-Bioresources Guangdong Laboratory for Lingnan Modern Agriculture Key Laboratory of Biology and Genetic Improvement of Horticultural Crops(South China) Ministry of Agriculture and Rural Affairs Guangdong Litchi Engineering Research Center College of Horticulture South China Agricultural University Dongguan Botanical Garden Section for Genetics and Evolutionary Biology Department of Biosciences University of Oslo College of Agriculture Guangxi University

At the physiological level, the interplay between auxin and ethylene has long been recognized as crucial for the regulation of organ abscission in plants. However, the underlying molecular mechanisms remain unknown. Here, we identified transcription factors involved in indoleacetic acid(IAA) and ethylene(ET)signaling that directly regulate the expression of INFLORESCENCE DEFICIENT IN ABSCISSION(IDA)and its receptor HAESA(HAE), which are key components initiating abscission. Specifically, litchi IDAlike 1(LcIDL1) interacts with the receptor HAESA-like2(LcHSL2). Through in vitro and in vivo experiments,we determined that the auxin response factor LcARF5 directly binds and activates both LcIDL1 and LcHSL2. Furthermore, we found that the ETHYLENE INSENSITIVE 3-like transcription factor LcEIL3 directly binds and activates LcIDL1. The expression of IDA and HSL2 homologs was enhanced in Lc ARF5and Lc EIL3 transgenic Arabidopsis plants, but reduced in ein3 eil1 mutants. Consistently, the expressions of LcIDL1 and LcHSL2 were significantly decreased in Lc ARF5-and LcEIL3-silenced fruitlet abscission zones(FAZ), which correlated with a lower rate of fruitlet abscission. Depletion of auxin led to an increase in 1-aminocyclopropane-1-carboxylic acid(the precursor of ethylene) levels in the litchi FAZ, followed by abscission activation. Throughout this process, LcRF5 and LcEIL3 were induced in the FAZ. Collectively, our findings suggest that the molecular interactions between litchi AUXIN RESPONSE FACTOR 5(LcARF5)–LcIDL1/LcHSL2 and LcEIL3–LcIDL1 signaling modules play a role in regulating fruitlet abscission in litchi and provide a long-sought mechanistic explanation for how the interplay between auxin and ethylene is translated into the molecular events that initiate abscission.

关键词： auxin ethylene fruit abscission IDA–HAE/HSL2 litchi

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Exploring non-curative endoscopic submucosal dissection:Current treatment optimization and future indication expansion

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World Journal of Gastroenterology 2024年第9期30卷 1257-1260页

作者： Yi-Nong Zhu Xiang-Lei yuan Wei Liu Yu-hang zhang Yi Mou Bing Hu Lian-Song Ye Department of Gastroenterology and Hepatology West China HospitalSichuan UniversityChengdu 610041Sichuan ProvinceChina

The increasing popularity of endoscopic submucosal dissection(ESD)as a treatment for early gastric cancer has highlighted the importance of quality assessment in achieving curative resections.This article emphasizes the significance of evaluating ESD quality,not only for curative cases but also for non-curative ones.Postoperative assessment relies on the endoscopic curability(eCura)classification,but management strategies for eCuraC-1 tumour with a positive horizontal margin are unclear.Current research primarily focuses on comparing additional surgical procedures in high-risk patients,while studies specifically targeting eCuraC-1 patients are limited.Exploring management strategies and follow-up outcomes for such cases could provide valuable insights.Furthermore,the application of molecular imaging using near-infrared fluorescent tracers holds promise for precise tumour diagnosis and navigation,potentially impacting the management of early-stage gastric cancer patients.Advancing research in these areas is essential for improving the overall efficacy of endoscopic techniques and refining treatment indications.

关键词： Early gastric cancer Endoscopic submucosal dissection Quality control Noncurative endoscopic submucosal dissection Near-infrared fluorescent tracer

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Nanoindentation behavior and creep-induced cracking of long-term crept austenitic steel at 650℃

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Journal of Iron and Steel Research(International) 2024年第2期31卷 464-474页

作者： Zhen zhang Yu-hang Duan Shuai Wang Jin-shan Chen An-zhe Wang Xiang-yang Mao yuan-ji Shi Jie zhang Ming Liu Zheng-fei Hu School of Materials Science and Engineering Nanjing Institute of TechnologyNanjing211167JiangsuChina Jiangsu Key Laboratory of Advanced Structural Materials and Application Technology Nanjing211167JiangsuChina Jiangsu Wind Power Engineering Technology Center Nanjing210023JiangsuChina Nanjing Vocational University of Industry Technology Nanjing210023JiangsuChina Baoshan Iron&Steel Co. Ltd.Shanghai201900China Fujian Provincial Key Laboratory of Terahertz Functional Devices and Intelligent Sensing School of Mechanical Engineering and AutomationFuzhou UniversityFuzhou350116FujianChina School of Materials Science and Engineering Tongji UniversityShanghai201804China

The grain boundary(GB)damage of long-term crept HR3C(25Cr–20Ni–Nb–N)austenitic steel with solid solution state was investigated by nanoindentation test accompanied with in-situ electron back-scattered diffraction.The corresponding microstructure was characterized by scanning electron microscopy and transmission electron microscopy.Results show that the increase in nanoindentation hardness at the GBs and triple grain junctions may be related to the dislocation accumulation and carbide growth during the creep.Coarsened M23C6 and dislocations piling-up at the GB accelerate the nucleation and coalescence of creep cavity along the GB.The nanoindentation hardness in grains varies with orientation of the stress axis.The orientation difference of neighbor grains may induce local high geometrically necessary dislocation densities and strain gradients near the GB,consequently causing stress concentration and subsequent crack growth at specific GBs.

关键词： Austenitic steel Creep Nanoindentation Grain orientation Creep-induced cracking

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Defective NH2-UiO-66 for effective Pb（Ⅱ） removal:Facile fabrication strategy,performances and mechanisms

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Progress in Natural Science:Materials International 2024年第2期34卷 420-428页

作者： Meng-yuan Liu Lu zhang Yu-hang Li Chong-Chen Wang Peng Wang Chen Zhao Huifen Fu Beijing Key Laboratory of Functional Materials for Building Structure and Environment Remediation School of Environment and Energy Engineering Beijing University of Civil Engineering and Architecture

Defective NH2-UiO-66 adsorbent（named as NH2-UiO-66-SD） was successfully fabricated via post-synthesis method with the aid of both sodium carbonate anhydrous（Na2CO3） and diethylenetriaminepentaacetic acid（DTPA）,in which the defective structure was confirmed by various characterizations.The as-obtained defective NH2-UiO-66-SD exhibited outstanding Pb（Ⅱ） sorption capacity(172.21 mg g-1) and rapid diffusion rate(29.87mg g-1min-0.5) at room temperature with optimal pH being 5.47.The Pb（Ⅱ） sorption behavior was conformed to pseudo-second-order kinetics and Langmuir model,demonstrating that the chemical sorption of the monolayer played a dominant model.As well,the thermodynamic parameters like standard Gibbs free energy change ΔG~o(-31.21 kJ mol-1),standard enthalpy change ΔH~o(12.79 kJ-1mol-1) and standard entropy change ΔS~o(146.73J mol-1K-1) revealed that the Pb（Ⅱ） sorption process of NH2-UiO-66-SD was spontaneous,endothermic and disordered.Furthermore,the NH2-UiO-66-SD exhibited desirable desorption and recirculation performances（removal efficiencies>85 % in 5 runs） with ideal stability.Moreover,the Pb（Ⅱ） sorption mechanism of NH2-UiO-66-SD mainly included the electrostatic attractions and coordinative interactions.Overall,this work offered an intriguing method of fabricating defective NH2-UiO-66 adsorbent,which vastly enhanced adsorption efficiency for toxic metal ions elimination from wastewater.

关键词： Adsorption Defect Mechanism NH2-UiO-66 Pb(II)

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New insight into Ca^(2+)-permeable channel in plant immunity

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Journal of Integrative Plant Biology 2024年第3期66卷 623-631页

作者： Wei Wang hang-yuan Cheng Jian-Min Zhou State Key Laboratory of Plant Genomics Institute of Genetics and Developmental BiologyChinese Academy of SciencesBeijing 100101China CAS Center for Excellence in Biotic Interactions University of Chinese Academy of SciencesBeijing 100049China College of Advanced Agricultural Sciences University of Chinese Academy of SciencesBeijing 100049China Hainan Yazhou Bay Seed Laboratory Sanya 572025China

Calcium ions(Ca^(2+)) are crucial intracellular second messengers in eukaryotic cells. Upon pathogen perception, plants generate a transient and rapid increase in cytoplasmic Ca^(2+)levels, which is subsequently decoded by Ca^(2+)sensors and effectors to activate downstream immune responses. The elevation of cytosolic Ca^(2+)is commonly attributed to Ca^(2+)influx mediated by plasma membranelocalized Ca^(2+)–permeable channels. However, the contribution of Ca^(2+)release triggered by intracellular Ca^(2+)-permeable channels in shaping Ca^(2+)signaling associated with plant immunity remains poorly understood. This review discusses recent advances in understanding the mechanism underlying the shaping of Ca^(2+)signatures upon the activation of immune receptors, with particular emphasis on the identification of intracellular immune receptors as non-canonical Ca^(2+)-permeable channels. We also discuss the involvement of Ca^(2+)release from the endoplasmic reticulum in generating Ca^(2+)signaling during plant immunity.

关键词： Ca^(2+)-permeable channels endoplasmic reticulum phosphorylation plant immunity resistosome

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