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Short-Term Influence of Burning on Species Abundance, Biomass Production, Wood Plant Density and Browsing Unit in an Albany Thicket of the Eastern Cape, South Africa

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Agricultural Sciences 2022年第1期13卷 74-85页

作者： Sive Tokozwayo Thubela Thubela Masibonge Gxasheka Siza Mthi Unathi Gulwa Nkululeko Nyangiwe Ayanda Kwaza Nokonwaba Jokani Nobulungisa Mgujulwa yanga mkabile Thozama Theophilus Bozo Amahle Sogoni Dö hne Agricultural Development Institute Department of Rural Development and Agrarian Reform Stutterheim South Africa Department of Plant Production Soil Science & Agricultural Engineering University of Limpopo Polokwane South Africa Department of Agriculture and Animal Health University of South Africa Florida South Africa Department of Rural Development and Agrarian Reform Land Use Management Gqeberha South Africa Department of Rural Development and Agrarian Reform Bathurst South Africa

Fire is regarded as management practice for maintaining grasslands and savannas. The vegetation occurring in fire prone areas becomes highly adapted to fire occurrences in savannas and grasslands. However, documentation on the influence of burning on vegetation is still limited in an albany thicket biome. The aim of the study was to evaluate the short-term influence of burning on species abundance, biomass production, wood plant density and browsing unit. Six plots (2500 m2) were demarcated;in each plot two parallel transects of 120 m2 with 5 m distance apart were measured. Three plots were burned in spring season, while no burning was done on the other remaining plots. Forty points per plot were obtained using step-point method to determine the relative abundance at burned and unburned plots. Woody plants occurred within a transect were identified, counted and recorded to determine density and browsing unit. Three quadrats (i.e. 0.25 m2) per plot were randomly laid within the transect;aboveground plant material within a quadrat were harvested. A total of 18 samples were harvested and oven dried at 60˚C for 48 hours to determine biomass production. The results showed that Themeda triandra (14%) and Panicum maximum (10%) were most abundant grass species at the burned plots. Burned plots had significantly higher biomass production (4804 kg/ha) compared to unburned plots (3641 kg/ha). Vachellia karoo (burned: 65.85% & unburn: 13.70%) and Searsia pallens (burned: 26.83% & unburned: 6.85%) were most dominant wood plant species at both burned and unburned plots. Burned plots had the highest browsing unit (3221 BU/ha) compared to unburned plots (2058 BU/ha). The decrease of woody plants at the burned plots proved that fire has a tremendous potential for managing woody plants. This study provided information on

关键词： Burning Browsing Density Relative Abundance

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Ticks, Demographics, Vegetation Cover, and Farmer’s Age Influence Red Meat Production in Resource-Poor Regions of Eastern Cape Province of South Africa

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Open Journal of Animal Sciences 2021年第4期11卷 682-696页

作者： Nkululeko Nyangiwe Sindisile Goni Thami Khethani Tanki Thubela Mlungisi Jansen Siza Mthi Mandla Yawa Sive Tokozwayo Unathi Gulwa Ntanganedzeni O. Mapholi Ishmael F. Jaja Luxolo Qokweni yanga mkabile mkabile Sindile Magoda Zoleka Ntondini Zamantungwa T. H. Khumalo Döhne Agricultural Development Institute Stutterheim South Africa Department of Agriculture and Animal Health University of South Africa Florida South Africa Department of Livestock and Pasture Science Faculty of Science and Agriculture University of Fort Hare Alice South Africa Department of Rural Development and Agrarian Reform Kokstad South Africa Department of Rural Development and Agrarian Reform Bathurst South Africa Department of Rural Development and Agrarian Reform Port Elizabeth South Africa Department of Rural Development and Agrarian Reform Queenstown South Africa National Institute for Communicable Diseases Sequencing Core Facility National Health Laboratory Service Johannesburg South Africa Department of Veterinary Tropical Diseases Faculty of Veterinary Science University of Pretoria Onderstepoort South Africa

This study presents an integrated examination of livestock production constraints associating with communal farming in six district municipalities (DMs) of the Eastern Cape Province. We collected data on demographic and socio-economic factors from 271 farmers randomly given questionnaires. About 26 Land Redistribution for Agricultural Development (LRAD) owned by communal farmers were surveyed to ascertain the condition of grazing land, meanwhile, tick species and distribution on cattle and goats found in 158 sampling sites of the study area were also recorded. From the results, a total of 34,929 adult ticks belonging to five genera and 10 species were encountered. The most abundant tick genera were Rhipicephalus of the subgenus Boophilus (68.91%), Amblyomma (20.72%), Hyalomma (8.64%), Ixodes (1.22%), and Haemaphysalis (0.51%). By geographic distributions, Amblyomma and Rhipic

关键词： Amblyomma Constraints Rangeland Conditions Rhipicephalus (Boophilus) microplus Tick Distribution South Africa

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日本结束“负利率时代”的政策演变、实践效果与前景分析

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现代日本经济 2024年第4期43卷 42-54页

作者：赵杨郭昭鹏吉林大学东北亚研究中心吉林长春130012 吉林大学东北亚研究院吉林长春130012

日本央行解除负利率政策、上调短期政策利率是在对日本历史利率环境、国内经济环境以及国际环境等多方面进行考量的基础上提出的,是日本央行摆脱结构性通缩、维持经济复苏的重要政策手段。日本央行希望通过解除负利率政策使日本利率正常... 详细信息

日本央行解除负利率政策、上调短期政策利率是在对日本历史利率环境、国内经济环境以及国际环境等多方面进行考量的基础上提出的,是日本央行摆脱结构性通缩、维持经济复苏的重要政策手段。日本央行希望通过解除负利率政策使日本利率正常化,形成“工资-通胀”之间的良性循环,维持现有来之不易的景气局面。但是日本央行渐进式加息的“鸽派态度”加速了日元贬值,导致输入型通货膨胀水平提升,减弱了日本银行加息政策带来的正面效应。在日本央行加息周期与美联储降息周期叠加的状态下,日本央行的加息政策可能无法有效解决日本结构性通缩问题,甚至难以维持现有复苏局面。在未来,日本央行有进一步加息的可能,但将以渐进式方式调整,由于经济形势的复杂性和多变性,政策影响的不确定性将被进一步放大。

关键词：日本负利率加息量化宽松短期利率政策

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内孤立波作用下缓波形立管动力特性研究

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船舶力学 2024年第6期28卷 803-817页

作者：余杨刘晓伟李振眠孙若飞杨政龙徐立新天津大学水利工程智能建设与运维全国重点实验室天津300072 天津大学天津市港口与海洋工程重点实验室天津300072

我国南海活跃着大量内孤立波,严重威胁海洋工程作业的安全。本文采用向量式有限元方法分析内孤立波作用下深海缓波形钢悬链立管动力特性,建立考虑触地段土反力和内孤立波载荷的缓波形钢悬链立管动力模型,根据mKdV方程求解内孤立波载荷,... 详细信息

我国南海活跃着大量内孤立波,严重威胁海洋工程作业的安全。本文采用向量式有限元方法分析内孤立波作用下深海缓波形钢悬链立管动力特性,建立考虑触地段土反力和内孤立波载荷的缓波形钢悬链立管动力模型,根据mKdV方程求解内孤立波载荷,基于向量式有限元梁单元编制Fortran计算程序。分析不同入射角内孤立波作用下立管的位移极值、张力及弯矩变化趋势,并比较缓波形立管与简单钢悬链立管在内孤立波作用下的动力特性。结果表明:内孤立波作用下,缓波形钢悬链立管会有较大的位移响应,特别是顶部悬垂段会有较大的水平位移;缓波形立管比简单钢悬链立管有更显著的张力变化幅值,有更加复杂的弯矩变化趋势。

关键词：缓波形钢悬链立管内孤立波向量式有限元 KdV理论动力响应

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Comprehensive damage evaluation of localized spallation of thermal barrier coatings

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Journal of Advanced Ceramics 2017年第3期6卷 230-239页

作者： Wei-Wei ZHANG Guang-Rong LI Qiang ZHANG Guan-Jun yanga State Key Laboratory for Mechanical Behavior of Materials School of Materials Science and Engineering Xi'an Jiaotong University Xi'an 710049 ChinaInstitute of Publication Science Chang'an University Xi'an 710064 ChinaSchool of Materials Science and Engineering Chang'an University Xi'an 710064 China State Key Laboratory for Mechanical Behavior of Materials School of Materials Science and Engineering Xi'an Jiaotong University Xi'an 710049 China State Key Laboratory for Mechanical Behavior of Materials School of Materials Science and Engineering Xi'an Jiaotong University Xi'an 710049 ChinaAECC Beijing Institute of Aeronautical Material Beijing 100095 China

Thermal barrier coatings (TBCs) enable the hot section part to work at high temperatures owing to their thermal barrier effect on the base metal components. However, localized spallation in the ceramic top-coat might occur after long duration of thermal exposure or thermal cycling. To comprehensively understand the damage of the top-coat on the overall hot section part, effects of diameter and tilt angle of the spallation on the temperature redistribution of the substrate and the top-coat were investigated. The results show that the spallation diameter and tilt angle both have a significant effect on the temperature redistribution of the top-coat and the substrate. In the case of the substrate, the maximum temperature increment is located at the spallation center. Meanwhile, the surface (depth) maximum temperature increment, having nothing to do with the tilt angle, increases with the increase of the spallation diameter. In contrast, in the case of the top-coat, the maximum temperature increment was located at the sharp corner of the spallation area, and the surface (depth) maximum temperature increment increases with the increase of both the spallation diameter and the tilt angle. Based on the temperature redistribution of the substrate and the top-coat affected by the partial spallation, it is possible to evaluate the damage effect of spalled areas on the thermal capability of TBCs.

关键词： thermal barrier coatings (TBCs) thermal property localized spallation damage evaluation

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Lightweight structure of a phase-change thermal controller based on lattice cells manufactured by SLM

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Chinese Journal of Aeronautics 2019年第7期32卷 1727-1732页

作者： Hao ZHOU Xiaoyu ZHANG Huizhong ZENG Huning yanga Hongshuai LEI Xiao LI Yaobing WANG Beijing Key Laboratory of Intelligent Space Robotic Systems Technology and Applications Beijing Institute of Spacecraft System EngineeringCASTBeijing100094China Institute of Advanced Structure Technology Beijing Institute of TechnologyBeijing100081China

Thermal controllers equipped with phase-change materials are widely used for maintaining the moderate temperatures of various electric devices used in spacecraft. Yet, the structures of amounts of thermal controllers add up to such a large value that restricts the employment of scientific devices due to the limit of rocket capacity. A lightweight structure of phase-change thermal controllers has been one of the main focuses of spacecraft design engineering. In this work, we design a lightweight phase-change thermal controller structure based on lattice cells. The structure is manufactured entirely with AlSi10 Mg by direct metal laser melting. The dimensions of the structure are 230 mm × 170 mm × 15 mm, and the mass is 190 g, which is 60% lighter than most traditional structures(500–600 g) with the same dimensions. The 3 D-printed structure can reduce the risk of leakage at soldering manufacture by a welding process. Whether the strength of the designed structure is sufficient is determined through mechanical analysis and experiments. Thermal test results show that the thermal capacity of the lattice-based thermal controller is increased by50% compared to that of traditional controllers with the same volume.

关键词： Lattice structure Lightweight Selective laser melting(SLM) Spacecraft Thermal controller

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On-orbit geometric calibration of satellite laser altimeters using infrared detectors and corner-cube retroreflectors

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International Journal of Digital Earth 2023年第1期16卷 2067-2088页

作者： Junfeng Xie Ren Liu Xiaomeng yanga Fan Mo Fangxu Zhang Lirong Liu Land Satellite Remote Sensing Application Center Ministry of Natural ResourcesBeijingPeople’s Republic of China School of Earth Sciences and Engineering Hohai UniversityNanjingPeople’s Republic of China Faculty of Geography Yunnan Normal UniversityKunmingPeople’s Republic of China

After being launched into orbit,the geometric calibration of a satellite laser altimeter will reduce errors in laser pointing and ranging caused by satellite vibrations during launch,environmental changes,and thermal effects during long-term operation,which guarantees the accuracy of measurement *** this study,a satellite laser geometric calibration method combining infrared detectors and corner-cube retroreflectors(CCRs)is ***,a CCR-based laser ranging error calibration method was established,and then a laser pointing error calibration model was derived based on a single infrared detector *** GaoFen-7(GF-7)satellite laser beam 2 as the experimental object,laser geometric calibration was realized using an infrared detector and CCR-measured ***,the accuracy of the proposed method was compared with that of other calibration methods,the CMLID and the *** results show that the accuracy of the proposed calibration method is equivalent to that of the CMLID and higher than that of the *** them,the accuracy of the laser pointing after calibration using the proposed method is better than 0.8 arcsec,and the elevation accuracy of the laser on flat,sloping,and mountainous terrains is better than 0.11 m,0.30 m,and 1.80 m,respectively.

关键词： Satellite laser calibration infrared detector corner-cube retroreflector(CCR) GaoFen-7(GF-7)satellite accuracy verification

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National Happiness at a Time of Economic Growth: A Tracking Study Based on CGSS Data

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Social Sciences in China 2013年第4期34卷 20-37页

作者： Liu Junqiang Xiong Moulin Su yanga School of Insurance Southwestern University of Finance and Economics Law School Southwestern University of Finance and Economics School of Social Sciences University of California Irvine

In order to respond to the ongoing debate over the Chinese people＇s sense of happiness and to assess the effects of macro-economic and policy changes on the life of ordinary people over the past decade, this study employs data from the Chinese General Social Survey （CGSS） to analyze the development and trends in the happiness （or subjective well-being） of the Chinese people over this period. Based on 5 time points and 44,166 samples, the study finds that the Chinese people＇s sense of happiness has risen steadily over the past decade, and that groups with different political affiliations, household registration, age, income, marital status and ethnicity have all witnessed, to varying degrees, a growing sense of happiness. Economic growth may be the crucial driving force here; if the economy contracts, people＇s sense of happiness may also fall. To maintain the coordinated development of the economy and society, more numerous and more detailed follow-up research on happiness needs to be conducted.

关键词： sense of happiness inequity economic growth

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Simple Synthesis of Single-crystalline Nanoplates of Magnesium Oxide

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Chinese Journal of Chemical Physics 2006年第5期19卷 438-442页

作者： Hai-xia Niu Qing yanga Fei Yu Kai-bin Tang Wei Zhou Hefei National Laboratory for Physical Sciences at Microscale University of Science and Technology of China Hefei 230025 China Department of Chemistry University of Science and Technology of China Hefei 230026 China Department of Modern Mechanics University of Science and Technology of China. Hefei 230027China

Single-crystalline nanoplates of magnesium oxide were successfully synthesized through a calcinations route from the newly produced Mg（OH）2 precursors, which were directly prepared from the commercial bulk magnesium powders under a hydrothermal process in the absence of any additions. Scanning electron microscope （SEM） analysis indicated that the nanoplates were 2-6 μm in average width and about 80 nm in thickness. Transmission electron microscopy （TEM） images revealed that there was large quantity of nanopores with diameters ranging from 5 to 40 nm distributed in these nanoplates. The room-temperature photoluminescence （PL） spectrum of the nanoplates illustrated a strong blue emission band at 416 nm and a weak green emission band at 559 nm. Brunauer-Emmett-Teller （BET） analysis exhibited a feature of high surface of 127.21 m^2/g for the products. The fabrication mechanism of the product was also discussed.

关键词： MgO Nanoplate Hydrothermal process

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Photoinduced Decomposition of Formaldehyde on Rutile TiO2（100）-（1×1）

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Chinese Journal of Chemical Physics 2018年第4期31卷 547-554,615页

作者： Xiao Chen Fang-liang Li Qing Guo Dong-xu Dai Xue-ming yanga State Key Laboratory of Molecular Reaction Dynamics Dalian Institute of Chemical PhysicsChinese Academy of ScienceDalian 115023China University of Chinese Academy of Sciences Beijing 100049China School of Physical Science and Technology ShanghaiTech UniversityShanghai 201210China

We have investigated the photoinduced decomposition of formaldehyde （CH2O） on a rutile TiO2（100）-（1×1） surface at 355 nrn using ternperature-prograrnrned desorption. Products, formate （HCOO）, methyl radical （CH3.）, ethylene （C2H4）, and methanol （CH3OH） have been detected. The initial step in the decomposition of CH2O on the futile TiO2（100）-（1×1） surface is the formation of a dioxyrnethylene intermediate in which the carbonyl O atom of CH2O is bound to a Ti atom at the five-fold-coordinated Ti4＋（Tisc） site and its carbonyl C atom bound to a nearby bridge-bonded oxygen （Oh） atom, respectively. During 355 nrn irradiation, the dioxymethylene intermediate can transfer an H atom to the Ob atom, thus forming HCOO directly, which is considered as the main reaction channel. In addition, the dioxyrnethylene intermediate can also transfer methylene to the Ob row and break the C-O bond, thus leaving the original carbonyl O atom at the Tisc site. After the transfer of methylene, several pathways to products are available. Thus, we have found that Ob atoms are intimately involved in the photoinduced decomposition of CH2O on the futile TiO2 （100）-（1× 1） surface.

关键词： Rutile TiO2 (100)- (1 ×x 1) Formaldehyde Temperature-programmed desorption,Photoinduced decomposition

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