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Contribution of winter fluxes to the annual CH_4, CO_2 and N_2O emissions from fres hwater marshes in the Sanjiang Plain

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Journal of Environmental Sciences 2006年第2期18卷 270-275页

作者： HAO Qing-ju wang yue-si SONG Chang-chun HUANG Yao Institute of Atmospheric Physics Chinese Academy of Sciences Beijing 100029 China Northeast Institute of Geography and Agricultural Ecology Chinese Academy of Sciences Changchun 130012 China Graduate School of the Chinese Academy of Sciences Beijing 100049 China

Wetlands at the interface of the terrestrial and aquatic ecosystems are intensive sites for mineralization of organic matter, but the contribution of winter season fluxes of CH4, CO2 and N2O from wetland ecosystems to annual budgets is poorly known. By using the static opaque chamber and GC techniques, fluxes of CH4, CO2 and N2O at two freshwater marshes in the Sanjiang Plain were measured during the winter seasons of 2002/2003 and 2003/2004 with contrasting snow conditions and flooding regimes. The results showed that there were significant interannual and spatial differences in CH4, CO2 and N2O fluxes. The Carex lasiocarpa marsh emitted more CH4 and CO2 while absorbed less N2O than the Deyeuxia angustifolia marsh during the winter seasons. Over the winter season, emissions of CH4, CO2 and N2O ranged from 0.42 to 2.41 gC/m^2, from 24.13 to 50.16 gC/m^2, and from -25,20 to -148.96 mgN/m^2, respectively. The contributions of winter season CH4 and CO2 emission to the annual budgets were 2.32% 4.62% and 22.17%- 27.97%, respectively. Marshes uptake N2O during the freezing period, while release N2O during the thawing period. The winter uptake equaled to 13.70%-86.69% of the growing-season loss. We conclude that gas exchange between soil/snow and the atmosphere in the winter season contributed greatly to the annual budgets and cannot be ignored in a cool temperate freshwater marsh in Northeast China.

关键词： freshwater marsh winter flux greenhouse gas emission Sanjiang Plain

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An improved gas chromatography for rapid measurement of CO2, CH4 and N2O

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Journal of Environmental Sciences 2006年第1期18卷 162-169页

作者： wang Ying-hong wang yue-si SUN Yang XU Zhong-jun LIU Guang-ren Institute of Atmospheric Physics Chinese Academy of Sciences Beijing 100029 China Graduate School of the Chinese Academy of Sciences Beijing 100049 China

Combining improved injector, gas line and valve-driving modules, a GC equipped with FID and ECD, could simultaneously measure CH4, CO2 and N2O in an air sample within 4 min. Test results showed that the system has high sensitivity, resolution and precision; the linear response range of the system meets the requirement of in situ flux measurements. Thus, the system is suitable for monitoring fluxes of main greenhouse gases in terrestrial ecosystem since it is easy to use, efficacious, stable and reliable to collect data.

关键词： GC valve emission of greenhouse gases ecosystem

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Switching,explosion,and chaos of multi-wavelength soliton states in ultrafast fiber lasers

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Science China(Physics,Mechanics & Astronomy) 2024年第7期67卷 82-90页

作者： Zhi-Zeng si yue-yue wang Chao-Qing Dai College of Optical Mechanical and Electrical EngineeringZhejiang A&F UniversityLin’an 311300China

Because of the complexity and difficulty of realizing a multi-wavelength soliton state,reports on its internal dynamic characteristics are *** this study,the switching and periodic soliton explosion processes of the multi-wavelength soliton state in a negative dispersion passively mode-locked fiber laser are *** generation of the multi-wavelength soliton state undergoes the process of noise,oscillation,and stable mode-locking,and the splitting and annihilation of solitons with different group velocities directly impact the generation and disappearance of three *** and negative dispersion lead to different group velocities of *** presence and displacement of solitons with different group velocities cause soliton collisions,which lead to soliton explosions.A soliton experiences relative phase oscillation,chaos,and oscillation,as well as convergence and separation before and after an *** an increase in parameters related to pump power,single-soliton oscillation,multi-wavelength solitons,and chaos are found in experiments and simulations,proving the relevance and reliability between simulation and experimental *** work promotes the dynamical study of multi-soliton collisions in nonlinear science and the development of chaos theory in multi-comb lasers.

关键词： multi-wavelength fiber laser soliton explosion chaos state switching real-time dynamics

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Synoptic Typing and Its Application for Evaluating Climatic Impact on Air Quality in Urumqi

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Atmospheric and Oceanic Science Letters 2010年第6期3卷 312-318页

作者： wang Li-Li wang yue-si LI Yuan-Yuan State Key Laboratory of Atmospheric Boundary Layer Physics and Atmospheric Chemistry Institute of Atmospheric Physics Chinese Academy of Sciences Beijing 100029 China Xinjiang Weather OJfice Urumqi 830002 China

An automated procedure employing principal-component analysis and a two-stage cluster analysis was developed to classify the synoptic meteorological conditions prevailing over Urumqi, one of the most heavily polluted cities in the world. six clusters representing different circulation patterns and air-mass characteristics were classified using surface- and upper-meteorological variables during the heating period from 2001 to 2008, and the relationships between synoptic clusters and air quality were evaluated. The heaviest air-pollution episodes occurred when Urumqi was in either an extremely cold, strong anticyclone or at the front of a migrating cyclone, both with light winds, wet surface air, and relatively dry upper air. Moderate pollution was seen when Urumqi was in the pre-cold/cold frontal passages with lower temperatures and light winds or moderate anticyclone with relatively warmer, drier air. When Urumqi was at the front of a migrating anticyclone or in a weak anticyclone with moderate winds and most warm, dry air, or in the cold/post-cold frontal passages with relatively strongly northerly airflows and precipitation, relatively good air quality could be seen. These results suggest that air pollution in Urumqi is very closely related to the synoptic meteorological conditions, which provides an important basis for not only the prediction and control of urban air-quality problems here but also for the analysis of the differential impacts of weather and pollution on human morbidity.

关键词： synoptic climatology automated meteorological classification air-pollution index (API) Urumqi

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Properties of Solar Radiation over Chinese Arid and Semi-Arid Areas

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Atmospheric and Oceanic Science Letters 2009年第3期2卷 183-187页

作者： HU Bo wang yue-si LIU Guang-Ren State Key Laboratory of Atmospheric Boundary Layer Physics and Atmospheric Chemistry （LAPC） Institute of Atmospheric Physics Chinese Academy of Sciences Beijing 100029 China

Climatic characteristics of broadband solarradiation (Rs) in Chinese arid and semi-arid areas are reported in this study. The annual average daily Rs in thearid and semi-arid areas is 16.3 ± 5.77 and 15.3 ± 5.16 MJm-2 d-1, respectively. The highest value (17.2 ± 5.84 MJm-2 d-1) appears in an arid area at Linze. The lowest valueappears in the semi-arid area of Ansai. Pronounced seasonal variation of Rs is observed with the highest value insummer and the lowest in winter. The clearness indexshowed similar seasonal pattern at most sites, with theminimum observed in the summer and the highest valuesin winter at both arid and semi-arid areas. The seasonalvariation of the ratio of Rs to its extraterrestrial value Kt inthe arid area is more significant than that observed in thesemi-arid region, and it is caused by the different range ofvariation of water vapor between arid and semi-arid areasThe seasonal fluctuations in Rs and Kt are mainly controlled by the water vapor content in these areas. Theaerosol particles have significant influence on Rs and Kt atstations with higher aerosol burden.

关键词： arid and semi-arid areas broadband solar radiation spatial distribution clearness index

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MRI对于阴道斜隔综合征及其分型诊断的重要应用价值

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中国CT和MRI杂志 2024年第7期22卷 141-143页

作者：王霞陈园园李鸿恩王思月杨朝湘广东省妇幼保健院影像科广东广州510010

目的通过阴道斜隔综合征MRI征象分析,探讨MRI对此病的诊断价值及限度。方法回顾性分析12例阴道斜隔综合征患者,均行常规MRI平扫及增强扫描。结果12例阴道斜隔综合征,MRI主要表现:双子宫双阴道畸形12例;右侧阴道斜隔9例,左侧阴道斜隔3例... 详细信息

目的通过阴道斜隔综合征MRI征象分析,探讨MRI对此病的诊断价值及限度。方法回顾性分析12例阴道斜隔综合征患者,均行常规MRI平扫及增强扫描。结果12例阴道斜隔综合征,MRI主要表现:双子宫双阴道畸形12例;右侧阴道斜隔9例,左侧阴道斜隔3例;11例合并同侧肾缺如(1例患者未行泌尿系检查);斜隔侧子宫腔妊娠2例;合并斜隔侧宫颈管至宫旁瘘道1例、斜隔侧阴道旁瘘管1例、阴道憩室1例;盆腔内积液并内膜异位灶3例,合并输卵管积血2例。结论MRI检查可直观显示阴道斜隔综合征的双子宫双阴道畸形,通过横冠矢三维定位清晰显示阴道斜隔、斜隔孔洞、宫颈间瘘管等细微结构,协助临床分型;并清晰显示宫腔及阴道积血、盆腔附件内膜异位、宫旁血肿等并发症。

关键词：阴道斜膈综合征磁共振成像肾缺如

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Trend and seasonal variations of atmospheric CH_4 in Beijing

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Journal of Environmental Sciences 2000年第3期12卷 369-374页

作者： wang yue\|si, wang Ming\|xing, LUO Dong\|mei, ZHENG Xun\|hua, ZHOU Li (Institute of Atmospheric Physics, Chinese Academy of Sciences, Beijing 100029, China) 中科院大气物理所北京 1 0 0 0 2

The atmospheric CH\-4 in Beijing is still increasing, even though its increasing rate has significantly decreased from 1.76%/a during 1985—1989 to 0.50%/a during 1990—1997. The seasonal variation of CH\-4 concentration showed a double\|peak pattern, one peak appearing in winter and the other in summer. It is evident that the annually seasonal variations of atmospheric CH\-4 in Beijing are different. From 1986 to 1997, the atmospheric CH\-4 increased by 185 ppbv, 37% and 21% of which were due to the increase in winter and in summer, respectively. After 1993, the annually seasonal increasing rate of CH\-4 concentration in summer (due to emission from biogenic sources) is negative while the increasing rate in winter (due to emission from non\|biogenic sources) is positive about 25 ppbv/a. As a result, the increase of CH\-4 emission from non\|biogenic sources in winter is the major reason that caused the annually seasonal increasing rate from 1993 to 1997. The biogenic sources in Beijing are shrinking while the non\|biogenic ones (such as fossil fuel combustion) are enlarging.

关键词： atmospheric CH\-4 increasing rate seasonal variation annually seasonal variation

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Variational Learned Talking-Head Semantic Coded Transmission System

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China Communications 2024年第7期21卷 37-49页

作者： yue Weijie si Zhongwei Key Laboratory of Universal Wireless Communications Ministry of EducationBeijing University of Posts and TelecommunicationsBeijing 100876China

Video transmission requires considerable bandwidth,and current widely employed schemes prove inadequate when confronted with scenes featuring *** by the strides in talkinghead generative technology,the paper introduces a semantic transmission system tailored for talking-head *** system captures semantic information from talking-head video and faithfully reconstructs source video at the receiver,only one-shot reference frame and compact semantic features are required for the entire ***,we analyze video semantics in the pixel domain frame-by-frame and jointly process multi-frame semantic information to seamlessly incorporate spatial and temporal *** modeling is utilized to evaluate the diversity of importance among group semantics,thereby guiding bandwidth resource allocation for semantics to enhance system *** whole endto-end system is modeled as an optimization problem and equivalent to acquiring optimal rate-distortion *** evaluate our system on both reference frame and video transmission,experimental results demonstrate that our system can improve the efficiency and robustness of *** to the classical approaches,our system can save over 90%of bandwidth when user perception is close.

关键词： semantic communications source-channel coding talking-head transmission variational modeling

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Wet deposition and scavenging ratio of air pollutants during an extreme rainstorm in the North China Plain

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Atmospheric and Oceanic Science Letters 2017年第5期10卷 348-353页

作者： Pan yue-Peng Zhu Xia-Ying Tian Shi-Li wang Li-Li Zhang Guo-Zhong Zhou Yan-Bo Xu Peng Hu Bo wang yue-si State Key Laboratory of Atmospheric Boundary Layer Physics and Atmospheric Chemistry (LAPC) Institute of Atmospheric Physics ChineseAcademy of Sciences Beijing China National Climate Center China Meteorological Administration Beijing China

Atmospheric wet deposition plays an important role in the supply of nutrients and toxic substances to terrestrial and aquatic environments. Although long-term（e.g. annual, multi-year） wet deposition is recorded well, pronounced and short-term changes in precipitation chemistry are less well investigated. In the present study, the precipitation chemistry and scavenging ratio of air pollutants were observed during an extreme torrential rain event（325.6 mm at the observation site） that occurred over 19–21 July 2016 in the North China Plain（NCP）. The scavenging ratio of particles showed a similar spatial distribution to that of the precipitation amount in the NCP, indicating the efficient removal of particulate matter due to the large amount and precipitation intensity of the storm. In addition, the scavenging ratio of water soluble ions was larger than that of organics and gaseous pollutants such as SO_2 and NO_2, likely due to their differences in water ***, raindrops incorporated more aerosol sulfate than gaseous compounds. Due to the heavy precipitation amount, almost all species in rainwater during this storm showed their lowest concentration but the highest flux compared with other rain events, indicating an important role played by this storm in terms of the substances received by the terrestrial and marine ecosystems of the region. However, the contribution of this storm to the annual chemical flux was lower than that of precipitation amount, indicating that the atmospheric compounds were scavenged below-cloud first and were then diluted by the cloud/rainwater. Future studies are needed in the context of the occurrence of extreme rainfall events in the NCP from the perspective of climate variability.

关键词： Extreme precipitation event rain chemistry wet deposition

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Design and tailoring of patterned ZnO nanostructures for perovskite light absorption modulation

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International Journal of Minerals,Metallurgy and Materials 2024年第5期31卷 855-861页

作者： Haonan si Xuan Zhao Qingliang Liao yue Zhang Academy for Advanced Interdisciplinary Science and Technology Beijing Advanced Innovation Center for Materials Genome EngineeringUniversity of Science and Technology BeijingBeijing 100083China Key Laboratory of Advanced Materials and Devices for Post-Moore Chips Ministry of EducationBeijing Key Laboratory for Advanced Energy Materials and TechnologiesSchool of Materials Science and EngineeringUniversity of Science and Technology BeijingBeijing 100083China

Lithography is a pivotal micro/nanomanufacturing technique,facilitating performance enhancements in an extensive array of devices,encompassing sensors,transistors,and photovoltaic *** key to creating highly precise,multiscale-distributed patterned structures is the precise control of the lithography ***,high-quality patterned ZnO nanostructures are constructed by systematically tuning the exposure and development times during *** optimizing these parameters,ZnO nanorod arrays with line/hole arrangements are successfully *** ZnO nanostructures with highly controllable morphology and structure possess discrete three-dimensional space structure,enlarged surface area,and improved light capture ability,which achieve highly efficient energy conversion in perovskite solar *** lithography process management for these patterned ZnO nanostructures provides important guidance for the design and construction of complex nanostructures and devices with excellent performance.

关键词： lithography patterned ZnO nanorod arrays light absorption perovskite solar cell

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