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Study of charge structure and radiation characteristic of intracloud discharge in thunderstorms of Qinghai-Tibet Plateau

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Science China Earth Sciences 2004年第Z1期47卷 108-114页

作者： ZHAGN Yijun DONG Wansheng ZHAO Yang zhang Guangshu zhang Hongfa CHEN Chengpin zhang tong Cold and Arid Regions Environmental and Engineering Research Institute Chinese Academy of Sciences Lanzhou 730000 China Cold and Arid Regions Environmental and Engineering Research Institute Chinese Academy of Sciences Lanzhou 730000 China Cold and Arid Regions Environmental and Engineering Research Institute Chinese Academy of Sciences Lanzhou 730000 China Cold and Arid Regions Environmental and Engineering Research Institute Chinese Academy of Sciences Lanzhou 730000 China Cold and Arid Regions Environmental and Engineering Research Institute Chinese Academy of Sciences Lanzhou 730000 China Cold and Arid Regions Environmental and Engineering Research Institute Chinese Academy of Sciences Lanzhou 730000 China Cold and Arid Regions Environmental and Engineering Research Institute Chinese Academy of Sciences Lanzhou 730000 China

The comprehensive observations on lightning discharges were conducted in Naqu area of Qinghai-Tibet Plateau in summer of 2002. The electric structures of thunderstorms and the characteristics of lightning discharges at initial stage were analyzed by using the observation data. The results show that most of intracloud (IC) lightning flashes were polarities inverted in thunderstorms with tripole electric charge structure and occurred between negative charge region located in the middle of the thunderstorm and positive charge region located at the bottom of the thunderstorm. The radiation characteristics of discharge processes in cloud with longer lasting time involved in Cloud-to-Ground (CG) lightning flashes were similar to that of IC discharges.A lot of radiation pulses were produced in these discharge processes. Because the IC discharges took place at the bottom of thundercloud and were near the ground, they may produce more serious damage to equipment on the ground therefore should not be neglected in lightning protection.

关键词： Qinghai-Tibet Plateau, characteristics of lightning discharges, charge structure of thunderstorm.

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Observation and study on the whole process of cloud-to-ground lightning using narrowband radio interferometer

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Science China Earth Sciences 2008年第5期51卷 694-708页

作者： zhang GuangShu ZHAO YuXiang QIE XiuShu zhang tong WANG YanHui CHEN ChengPin Laboratory for Climate Environment and Disasters of Western China Cold and Arid Regions Environmental and Engineering Re-search InstituteChinese Academy of SciencesLanzhou 730000China Laboratory for Middle Atmosphere and Global Environment Observation(LAGEO) Institute of Atmospheric PhysicsChinese Academy of SciencesBeijing 100029China Tianshui Normal College Tianshui 741001China

A narrowband radio interferometer has been developed and used to locate the entire sources of VHF radiations from a negative cloud-to-ground (CG) lightning discharge which contains 19 strokes. This system uses five antennas to form an array consisting of short- and long-baselines along two or- thogonal directions. The system error which comes from frequency conversion is reduced by phase detection through direct high frequency amplifying. An interactive graphic analysis procedure is used to remove the fringe ambiguities which exist inherently in interferometry and to determine the direction of lightning radiation sources in two dimensions (azimuth and elevation) as a function of time at a time resolution of microsecond orders. With the developed system, the whole progression process in time and space of a lightning flash can be reconstructed. In this paper, combining the synchronous data of electric filed change and VHF radiation, the whole processes of an example negative CG flash have been studied in detail. It is found that the preliminary breakdown event of the CG flash started from negative charge region and exhibited firstly a downward pregression and then an upward propagation. There were very intense and continuous radiations during stepped leaders which became much stronger when the first return stroke began. In contrast, there were less and only discrete radiations during dart leaders. Stepped leader and dart leader may transform to each other depending on the state of the ionization of the path. The progression speed of initial stepped leaders was about 105 ms?1, while that was about 4.1×106 and 6.0×106 ms?1 for dart leaders and dart-stepped leaders, respectively. M events produced hook-shaped field changes accompanied by active burst of radiations at their begin- nings. Followed these active radiation processes, M events appeared to contact finally into conducting main discharge channels. The mean progression speed of M events was about 7×107 ms?1, great

关键词： lightning narrowband interferometer dart leader K events M events the whole process of cloud-to-ground lightning

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Photochemical fixation and reduction of sulfur dioxide to sulfide by tetraphenylporphyrin magnesium:Spectroscopic and kinetic studies

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Science China Chemistry 2012年第9期55卷 1881-1886页

作者： zhang JianBin LI ChunPing HUO TianRui LI Qiang zhang tong WEI XiongHui College of Chemical Engineering Inner Mongolia University of TechnologyHuhhot 010051China Department of Applied Chemistry College of Chemistry&Molecular EngineeringPeking UniversityBeijing 100871China

The photochemical reaction of sulfur dioxide （802） with tetraphenylporphyrin magnesium （MgTPP） has been investigated in dichloromethane （CH2C12） solution at room temperature with illumination by visible light. Conventional fluorescence, UV-vis, and MS spectral analyses showed that under these conditions, SO2 was initially photochemically fixed by MgTPP to form a 1：1 molecular adduct. On continued irradiation and maintaining the flow of SO2, MS and XRD results showed that MgTPP is re- markably effective in the photochemical reduction of SO2 to sulfide （S2 ）. The kinetics of the photochemical reaction of MgTPP with SO2 was studied in a SO2-saturated solution. Under irradiation, the reaction follows pseudo first order kinetics for MgTPP, having a half-life decreasing from 106 to 57 min as the illumination intensity is increased from 350 to 600 Lm. This investigation of the photochemical fixation and reduction of SO2 by MgTPP is of key interest in elucidating fundamental pho- tochemical reaction mechanisms associated with porphyrins in the presence of SO2; furthermore, the analysis of the photo- chemical reaction may offer new opportunities for the fixation and reduction of SO2 to less harmful species.

关键词： photoreduction photochemical fixation irradiation sulfur dioxide tetraphenylporphyrin magnesium sulfide

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Confidence domain in the stochastic competition chemostat model with feedback control

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Applied Mathematics(A Journal of Chinese Universities) 2018年第4期33卷 379-389页

作者： XU Chao-qun YUAN San-ling zhang tong-hua Faculty of Science Jiangsu University College of Science University of Shanghai for Science and Technology Department of Mathematics Swinburne University of Technology

This paper studies a stochastically forced chemostat model with feedback control in which two organisms compete for a single growth-limiting substrate. In the deterministic counterpart, previous researches show that the coexistence of two competing organisms may be achieved as a stable positive equilibrium or a stable positive periodic solution by different feedback schedules. In the stochastic case, based on the stochastic sensitivity function technique,we construct the confidence domains for different feedback schedules which allow us to find the configurational arrangements of the stochastic attractors and analyze the dispersion of the random states of the stochastic model.

关键词： stochastic chemostat model feedback control white noise confidence domain

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Electro-acupuncture at Zusanli(ST 36) to improve lower extremity motor function in sensory disturbance patients with cerebral stroke A randomized controlled study of 240 cases

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Neural Regeneration Research 2009年第11期4卷 935-940页

作者： Weijun Gong tong zhang Lihua Cui YuqiYang Xinting Sun Department of Neurological Rehabilitation Beijing Boai Hospital China Rehabilitation Research Centre School of Rehabilitation MedicineCapital Medical University Beijing 100068 China

BACKGROUND： Studies have shown that sensory transduction is a way to introduce needle sensation. OBJECTIVE： To observe the influence of electro-acupuncture at the ＂Zusanll＂（ST 36） point on lower extremity motor function in various sensory disturbance patients with cerebral stroke. DESIGN, TIME AND SETTING： A randomized, controlled, clinical study was performed at the Department of Neurological Rehabilitation, China Rehabilitation Research Centre from September 2006 to June 2008. PARTICIPANTS： Patients with first-time cerebral infarction or hemorrhage, or with a stroke history, but no neurodysfunction （single damage）, were selected for this study. The subjects were right-handed and disease state was stable. A total of 240 inpatients were randomly assigned to the following groups： electro-acupuncture （n = 124） and control （n = 116）. The two groups were further assigned into sub-groups： no sensory disturbance, superficial sensory disturbance, deep sensory disturbance, and deep and superficial sensory disturbance. METHODS： On the basis of routine limb function training, the acupoint Zusanliwas utilized in all patients from the electro-acupuncture group. Perpendicular acupuncture was 3.0-4.0 cm deep. An electric acupuncture instrument was connected when patients developed the needle sensation, deqi. A stimulation pattern consisting of distant and dense waves of 50 Hz was used to elicit slight dorsal foot extension. Acupuncture was administered 5 times per week, 30 minutes per session, for 6 weeks in total. MAIN OUTCOME MEASURES： FugI-Meyer assessment （FMA） was used to evaluate lower extremity motor function; Ver.1.0 gait analysis to estimate gait （step frequency, step speed, and step scope）; lower extremity Composite Spasticity Scale （CSS） to estimate muscle spastic degree. RESULTS： Following treatment, motor function improved in both groups. Compared with the control group, FMA score, step speed, step frequency, and step scope were increased in the electro-acupuncture

关键词： electro-acupuncture Zusanli (ST 36) sensory disturbance motor function sensory input

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Benggang segmentation via deep exchanging of digital orthophoto map and digital surface model features

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International Soil and Water Conservation Research 2024年第3期12卷 589-599页

作者： Shengyu Shen Jiasheng Chen Dongbing Cheng Honghu Liu tong zhang Department of Soil and Water Conservation Changjiang River Scientific Research Institute of Changjiang Water Resources CommissionWuhan430010China Research Center on Mountain Torrent&Geologic Disaster Prevention Ministry of Water ResourcesWuhan430010China State Key Laboratory of Information Engineering in Surveying Mapping and Remote Sensing(LIESMARS)Wuhan UniversityWuhan430079China

Benggang is a typical fragmented erosional landscape in southern and southeastern China,posing sig-nificant risk to the local residents and economic ***,an efficient and accurate fine-grained segmentation method is crucial for monitoring the Benggang *** this paper,we propose a deep learning-based automatic segmentation method for Benggang by integrating high-resolution Digital Orthophoto Map(DOM)and Digital Surface Model(DSM)*** DSM data is used to extract slope maps,aiming to capture primary morphological *** proposed method consists of a dual-stream convolutional encoder-decoder network in which multiple cascaded convolutional layers and a skip connection scheme are used to extract morphological and visual features of the Benggang *** rich discriminative information in the DOM and slope data is fused by a channel exchanging mechanism that dynamically exchanges the most discriminative features from either the DOM or DSM stream ac-cording to their importance at the channel *** experiments were conducted on a chal-lenging dataset collected from Guangdong Province,China,and the results show that the proposed channel exchanging network based deep fusion method achieves 84.62%IoU in Benggang segmentation,outperforming several existing unimodal or multimodal *** proposed multimodal segmen-tation method greatly improves the efficiency of large-scale discovery of Benggang,and thus is important for the management and restoration of Benggang in southern and southeastern China,as well as the monitoring of other similar erosional landscapes.

关键词： Benggang segmentation Deep fusion Channel exchanging DOM DSM

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Red sprites over thunderstorms in the coast of Shandong Province,China

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Chinese Science Bulletin 2008年第7期53卷 1079-1086页

作者： YANG Jing QIE XiuShu zhang GuangShu ZHAO Yang zhang tong Laboratory for Middle Atmosphere and Global Environment Observation (LAGEO) Institute of Atmospheric Physics Chinese Academy of Sciences Beijing 100029 China Laboratory for Climate Environment and Disasters of Western China (LCEDWC) Cold and Arid Regions Environmental and Engineering Research Institute Chinese Academy of Sciences Lanzhou 730000 China

Red sprites, different from lightning flashes occurring in the troposphere, are large and brief dis-charges which appear in the altitude range from about 40 to 90 km above large thunderstorms and are usually caused by cloud-to-ground lightning discharges (CGs). A total of 17 sprites over two thunder-storms were first observed during the summer of 2007. One of the sprites occurred on July 28 above a thunderstorm in Guan County and the center of the storm was about 272 km from the observation site. The other sprites were recorded at the late night of August 1 and in the early morning of August 2, and the storm center was about 315 km away. All of the observed sprites occurred in cluster, and their appearances were very different, including 'columniform sprites', 'columniform sprites' with angel-like wings, 'carrot sprites', 'dancing sprites', etc. The duration of the sprites varied from a minimum of 40 ms to a maximum of 160 ms with a geometric mean (GM) of 61 ms. The time delay between parental positive cloud-to-ground lightning flashes (+CGs) and the associated sprites varied from 3.4 to 11.8 ms with a GM of 7.1 ms. The ratio of the number of +CGs to the total number of CGs during the time period with sprites was 7 times larger than that when no sprites occurred. Sprites did not appear fre-quently at the time when the convective activity is strong but when the thunderstorm starts to become weak.

关键词：雷暴海岸山东中国

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Influence of Aging Time on Microstructure and Corrosion Behavior of a Cu-Bearing 17Cr–1Si–0.5Nb Ferritic Heat-Resistant Stainless Steel

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Acta Metallurgica Sinica(English Letters) 2020年第9期33卷 1289-1301页

作者： tong zhang Ying Han Wen Wang Yang Gao Ying Song Xu Ran Key Laboratory of Advanced Structural Materials Ministry of EducationChangchun University of TechnologyChangchun 130012China School of Metallurgical Engineering Xi'an University of Architecture and TechnologyXi’an 710055China

17 Cr–1 Si–0.5 Nb–1.2 Cu ferritic heat-resistant stainless steel was aged at 750 °C from 10 min to 30 h to simulate time aging and study the microstructural evolution and its effect on corrosion behavior by using optical microscopy, scanning electron microscopy, transmission electron microscopy, potentiodynamic polarization, electrochemical impedance spectroscopy, and the Mott–Schottky approach. Four types of precipitates were discovered, including ε-Cu, NbC, Fe3 Nb3 C, and Fe2 Nb-type Laves phase. The nano-sized ε-Cu phase forms first, and its fraction follows the parabolic law change and is the largest. Compared to NbC and Fe3 Nb3 C particles, the coarsening of the Laves phase is the most pronounced. The aging process is divided into three parts: early-aged(0–5 h), peak-aged(5 h), and over-aged(5–30 h). However, the corrosion resistance is reduced in the early-aged stage of 0–2 h. Further extending the aging time to 30 h, the corrosion resistance is gradually improved. This change may be related to the competitive relationship between the beneficial effects of the Cu-rich phase and the harmful effects of Nb-containing particles. The dissolved Cu on the surface becomes more effective for the suppression of the anodic dissolution by the formation of ionic compounds of chlorine, thereby reducing the deterioration of corrosion resistance caused by Nb-rich precipitation.

关键词： Ferritic stainless steel Aging Precipitation Electrochemical behavior Passive film

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Facile synthesis of Co and Ce dual-doped Ni3S2 nanosheets on Ni foam for enhanced oxygen evolution reaction

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Nano Research 2020年第8期13卷 2130-2135页

作者： Xiaoxia Wu tong zhang Jiaxu Wei Pengfei Feng Xingbin Yan Yu Tang Laboratory of Clean Energy Chemistry and Materials State Key Laboratory of Solid LubricationLanzhou Institute of Chemical Physics Chinese Academy of SciencesLanzhou730000China State Key Laboratory of Applied Organic Chemistry Key Laboratory of Nonferrous Metal Chemistry and Resources Utilization of Gansu ProvinceCollege of Chemistry and Chemical EngineeringLanzhou UniversityLanzhou730000China Center of Materials Science and Optoelectronics Engineering University of Chinese Academy of SciencesBeijing100049China

Nano Research volume 13,pages2130–2135(2020)Cite this article 376 Accesses 2 Citations Metrics details Abstract Developing efficient and stable oxygen evolution reaction(OER)electrocatalysts via doping strategy has well-documented for electrochemical water ***,a homogeneous structure(denoted as Co/Ce-Ni3S2/NF)composed of Co and Ce dual doped Ni3S2 nanosheets on nickel foam was synthesized by a facile one-step hydrothermal *** and Ce dopants are distributed inside the host sulfide,thereby raising the active sites and the electrical ***,the CeOx nanoparticles generated by part of the Ce dopants as a cocatalyst further improve the catalytic activity by adding defective sites and enhancing the electron *** a consequence,the obtained Co/Ce-Ni3S2/NF electrode exhibits better electrocatalytic activity than single Co or Ce doped Ni3S2 and pure Ni3S2,with low overpotential(286 mV)at 20 mA-cm^−2,a small Tafel slope and excellent long-term durability in strong alkaline *** results presented here not only offer a novel platform for designing transition metal and lanthanide dual-doped catalysts,but also supply some guidelines for constructing catalysts in other catalytic applications.

关键词： electrocatalyst oxygen evolution reaction dual-doping CeOx Ni3S2

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Citrate-promoted dissolution of nanostructured manganese oxides:Implications for nano-enabled sustainable agriculture

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Journal of Environmental Sciences 2023年第3期125卷 492-498页

作者： Di Fu Lin Duan Xiaoyan Li Chuanjia Jiang tong zhang Wei Chen Ministry of Education Key Laboratory of Pollution Processes and Environmental Criteria Tianjin Key Laboratory of Environmental Remediation and Pollution ControlCollege of Environmental Science and EngineeringNankai UniversityTianjin 300350China

Nanostructured manganese oxides (nano-MnO_(x)) have shown great promises as versatile agrochemicals in nano-enabled sustainable agriculture,owing to the coupled benefits of controlled release of dissolved Mn2+,an essential nutrient needed by plants,and oxidative destruction of environmental organic ***,we show that three δ-MnO_(2)nanomaterials consisting of nanosheet-assembled flower-like nanospheres not only exhibit greater kinetics in citrate-promoted dissolution,but also are less prone to passivation,compared with three α-MnO_(2)nanowire *** better performance of the δ-MnO_(2)nanomaterials can be attributed to their higher abundance of surface unsaturated Mn atoms–particularly Mn(Ⅲ)–that is originated from their specific exposed facets and higher abundance of surface defects *** results underline the great potential of modulating nanomaterial surface atomic configuration to improve their performance in sustainable agricultural applications.

关键词： Nano-enabled sustainable agriculture Nanostructured manganese oxides Controlled release Unsaturated Mn atoms Mn(III)

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