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Agricultural sciences in china 2002年第12期1卷 1344-1349页

作者： YANG Jian-min , MENG Qing-rui, PENG wei-xiu, WANG Xue-dong , zhang Yuan-hui , SUN Fu-zai, ZHAO Ting-chang and LI Shao-hua(College of Forestry , Hebei Agricultural University, Baoding 071000 , P. R. china institute of Plant Protection ,chinese Aeademy of Argricultural sciences , beijing 100094 , P. R. china College of Horticultural sciences ,china Agricultural University , beijing 100094 , P. R. china) College of Forestry Hebei Agricultural University Baoding 071000 P.R.China institute of Plant Protection Chinese Aeademy of Argricultural Sciences Beijing 100094 P.R.China College of Horticultural sciences China Agricultural University Beijing 100094 P.R.China

Effects of low temperature and INA bacteria on the change of chlorophyll a fluorescence in young fruit from two apricot cultivars were investigated. Low temperature decreased the potential activity (Fv/ Fo), conversion efficiency of primary light energy (Fv/Fm)of PS II and photochemical quenching (qP) in young fruit of two apricot cultivars. Low temperature enhanced non-photochemical quenching qN, decreasing the quantum yield of photosynthetic electron transfer. The presence of ice nucleating active (INA) bacteria intensified the effects of low temperature, raised the injury temperature threshold from - 4℃ to - 2 - - 3℃. INA bacteria can be a factor to induce frost susceptibility of apricot fruit. The amount of damaged PS I activity center was related to apricot fruit size and cultivar.

关键词： Apricot Young fruit Chlorophyll a fluorescence PS II activity center qP qN Cold resistance Ice nucleating active bactetia

面向短时/断续工作制的电机系统固–液相变热管理技术及应用发展

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中国电机工程学报 2024年第1期44卷 280-292,I0023页

作者：邱书恒王海峰熊斌花为邹亮张驰中国科学院宁波材料技术与工程研究所浙江省宁波市315201 中国科学院电工研究所北京市海淀区100190 东南大学电气工程学院江苏省南京市210096 山东大学电气工程学院山东省济南市250061

固–液相变现象表现出的潜热特性可有效平抑瞬时温升,将其应用于航天航空、奔越式机器人、新能源汽车、数控机床等电机热管理系统,可有效提高短时工作制或断续周期性工作制(S2—S8)下运行的伺服电驱动系统的瞬态性能。为了总结归纳固–... 详细信息

固–液相变现象表现出的潜热特性可有效平抑瞬时温升,将其应用于航天航空、奔越式机器人、新能源汽车、数控机床等电机热管理系统,可有效提高短时工作制或断续周期性工作制(S2—S8)下运行的伺服电驱动系统的瞬态性能。为了总结归纳固–液相变材料的电机系统热管理技术及其应用现状,该文针对固–液相变材料特性、系统数值计算与仿真模拟、样机实验测试方法、相变热管理系统结构等4个方面开展调研,并提出亟待解决的关键技术问题。研究发现:目前阶段石蜡和低温熔盐是适合电机系统的最佳相变介质,但仍存在导热系数较低的问题,需通过改性强化解决;通过机壳灌注相变材料,可有效实现温升平抑,但尚缺乏有针对性的热路拓扑设计;采用焓–多孔方法是模拟相变过程的理想手段,但糊状区参数的取值缺乏理论指导;最后,固–液相变过程的测试中侵入式传感器易对电磁、热、流场的自然演变过程产生干扰。

关键词：电机系统热管理技术 S2—S8工作制温升平抑固–液相变材料电系统结构分析方法实验测试方法

The Jiao Tong University Spectroscopic Telescope Project

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Astronomical Techniques and Instruments 2024年第1期1卷 16-30页

作者： JUST Team Chengze Liu Ying Zu Fabo Feng Zhaoyu Li Yu Yu hua Bai Xiangqun Cui Bozhong Gu Yizhou Gu Jiaxin Han Yonghui Hou Zhongwen Hu Hangxin Ji Yipeng Jing wei Li Zhaoxiang Qi Xianyu Tan Cairang Tian Dehua Yang Xiangyan Yuan Chao Zhai Congcong zhang Jun zhang Haotong zhang Pengjie zhang Yong zhang Yi Zhao Xianzhong zheng Qingfeng Zhu Xiaohu Yang Tsung-Dao Lee institute Shanghai Jiao Tong UniversityShanghai 200240China Department of Astronomy School of Physics and AstronomyShanghai Jiao Tong UniversityShanghai 200240China Nanjing institute of Astronomical Optics&Technology Chinese Academy of SciencesNanjing 210042China University of chinese academy of sciences NanjingNanjing 211135China University of chinese academy of sciences Beijing 101408China Lenghu Technology Innovation Industrial Park Management Committee Lenghu 817400China Shanghai Astronomical Observatory Chinese Academy of SciencesShanghai 200030China Department of Astronomy University of Science and Technology of ChinaHefei 230026China National Astronomical Observatories Chinese Academy of SciencesBeijing 100101China Purple Mountain Observatory Chinese Academy of SciencesNanjing 210023China

The Jiao Tong University Spectroscopic Telescope(JUST)is a 4.4-meter f/6.0 segmented-mirror telescope dedicated to spectroscopic *** JUST primary mirror is composed of 18 hexagonal segments,each with a diameter of 1.1 *** provides two Nasmyth platforms for placing science *** Nasmyth focus fits a field of view of 10′and the other has an extended field of view of 1.2°with correction optics.A tertiary mirror is used to switch between the two Nasmyth *** will be installed at a site at Lenghu in Qinghai Province,china,and will conduct spectroscopic observations with three types of instruments to explore the dark universe,trace the dynamic universe,and search for exoplanets:(1)a multi-fiber(2000 fibers)medium-resolution spectrometer(R=4000-5000)to spectroscopically map galaxies and large-scale structure;(2)an integral field unit(IFU)array of 500 optical fibers and/or a long-slit spectrograph dedicated to fast follow-ups of transient sources for multi-messenger astronomy;(3)a high-resolution spectrometer(R~100000)designed to identify Jupiter analogs and Earth-like planets,with the capability to characterize the atmospheres of hot exoplanets.

关键词： Astronomical instrumentation Optical telescopes Large-scale structure of the universe Redshift surveys Time domain astronomy Exoplanet astronomy

Amelioration of habitat since the early Holocene contributed to the origin of agriculture in the farming-pastoral zone of northern china

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Science china Earth sciences 2024年第8期67卷 2535-2546页

作者： Xin JIA Zhiping zhang Yonggang SUN Runqi JIANG Shuangwen YI wei CHEN Jue SUN Guoqiang LI Shuzhi WANG Enrui LI Xiaonong HU Qingchun BAO Harry F.LEE huayu LU Jiangsu Center for Collaborative Innovation in geographical Information Resource Development and Application Nanjing 210023China Schlool of History and Culture Chifeng UniversityChifeng 024000China School of Geography and Ocean Science Nanjing UniversityNanjing 210023China State Key Laboratory of Palaeobiology and Stratigraphy Nanjing Institute of Geology and PalaeontologyChinese Academy of SciencesNanjing 210008China Key Laboratory of Western china’s Environmental Systems(Ministry of Education) College of Earth and Environmental SciencesLanzhou UniversityLanzhou 730000China institute of Archaeology Chinese Academy of Social SciencesBeijing 100710China Ulanqab Museum Ulanqab 012000China The institute of Cultural Relics and Archaeology Hohhot 010011China Department of Geography and Resource Management The Chinese University of Hong KongHong Kong 999077China Key Laboratory of Virtual Geographic Environment(Ministry of Education of PRC) Nanjing Normal UniversityNanjing 210023China School of Geography Nanjing Normal UniversityNanjing 210023China institute of Environmental Archaeology Nanjing Normal UniversityNanjing 210023China

The origin of agriculture in the farming-pastoral zone of northern china remains in *** central region of the Inner Mongolia Plateau is located in the core area of the farming-pastoral zone;thus,it is a critical region for exploring the origin of the dryland farming system in northern *** study selected the Yumin Site and Banan Site,which belong to the Yumin Culture-the beginning of Neolithic culture in Inner Mongolia-as the research *** on the quartz optically stimulated luminescence(OSL)dating on the sedimentary sections from the Yumin site(YM)and Banan site(BN1 and BN2),the Holocene chronology framework of each section was *** that,by identifying carbonized grains in the Yumin site and the multi-proxy analysis of each section,we investigated the relationship between the origin of agriculture and climate change in this *** results revealed that the timing of the origin of agriculture recorded in the Yumin site lagged behind the timing of a significant increase of precipitation during the early Holocene but coincided with the timing of a significant increase of vegetation around 8.4 *** phenomenon was further confirmed by the published high-resolution paleoenvironmental records from the surrounding area of the Yumin *** propose that with the gradual amelioration of hydrothermal conditions since the beginning of the Holocene,the regional ecosystem had been improved,resulting in the gradual conversion of the land surface from infertile sand to organic-rich soil,providing an appropriate environmental foundation for the origin of dryland farming in northern china around 8.4 *** study highlighted that the“accumulative environmental effects”during the early Holocene played a vital role in the origin of agriculture in northern china and provided a reference for agricultural management in the context of future climate change.

关键词： Origin of agriculture Accumulative environmental effects Yumin Culture Northern china Holocene

Application of multi-pulse optical imaging to measure evolution of laser-produced counter-streaming flows

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chinese Physics B 2017年第5期26卷 165-169页

作者：袁大伟李玉同朱保君李彦霏仲佳勇魏会冈刘畅原晓霞张喆梁贵云王菲鹿李芳赵家瑞华能朱宝强朱健强江少恩杜凯丁永坤赵刚张杰 Key Laboratory of Optical Astronomy National Astronomical Observatories Chinese Academy of Sciences National Laboratory for Condensed Matter Physics Institute of Physics Chinese Academy of Sciences School of Physical sciences University of Chinese Academy of Sciences Collaborative Innovation Center of IFSA(CICIFSA) Shanghai Jiaotong University Department of Astronomy Beijing Normal University National Laboratory on High Power Lasers and Physics research Center for Laser Fusion China Academy of Engineering Physics Key Laboratory for Laser Plasmas(Ministry of Education)and Department of Physics and Astronomy Shanghai Jiao Tong University

A counter-streaming flow system is a test-bed to investigate the astrophysical collisionless shock（CS） formation in the laboratory. Electrostatic/electromagnetic instabilities, competitively growing in the system and exciting the CS formation, are sensitive to the flows parameters. One of the most important parameters is the velocity, determining what kind of instability contributes to the shock formation. Here we successfully measure the evolution of the counter-streaming flows within one shot using a multi-pulses imaging diagnostic technique. With the technique, the average velocity of the high-density-part（ne ≥ 8–9 × 10^19cm^-3） of the flow is directly measured to be of ～ 10^6cm/s between 7 ns and 17 ***, the average velocity of the low-density-part（ne ≤ 2 × 10^19cm^-3） can be estimated as ～ 10^7cm/s. The experimental results show that a collisionless shock is formed during the low-density-part of the flow interacting with each other.

关键词： streaming counter interacting exciting instability determining diagnostic colors distinguish gamma

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荒漠化重建地区土壤有机碳动态研究

水土保持学报 2004年第3期18卷 74-77,89页

作者：程淑兰欧阳华牛海山王琳田玉强张锋中国科学院地理科学与资源研究所北京100101 中国科学院研究生院北京100039

土壤有机碳(Soilorganiccarbon,SOC)是反映土地荒漠化的重要指标。本研究以陕西省榆林市为例,开展小区域沙漠化重建地区SOC动态的实证研究。SOC数据来源于1982年土壤普查和2003年重复采样,土样的采集、分析和统计方法分别为土钻取土法... 详细信息

土壤有机碳(Soilorganiccarbon,SOC)是反映土地荒漠化的重要指标。本研究以陕西省榆林市为例,开展小区域沙漠化重建地区SOC动态的实证研究。SOC数据来源于1982年土壤普查和2003年重复采样,土样的采集、分析和统计方法分别为土钻取土法、重铬酸钾氧化法、吸管法和面积加权法。研究结果表明:SOC含量与粗砂粒显著负相关(R=-0.50,a=0.01),与粘粒显著正相关(R=-0.45,a=0.05),20年间土壤颗粒细化趋势比较明显;20年间原始剖面、1m深和耕层SOC含量、密度和储量都有不同程度的增加,其中对人类活动最敏感的耕层土壤变化最显著,SOC含量、密度和储量分别增加了0.55g/kg,0.15kg/m2,10.07GgC。该研究结果表明防风固沙、可持续性农耕等措施会卓有成效地促进土地沙漠化的恢复和重建。

关键词：荒漠化重建地区土壤有机碳动态分析

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云南东川地区层状地貌面的成因

山地学报 2004年第2期22卷 165-174页

作者：冯金良崔之久张威李德文刘耕年朱立平中国科学院地理科学与资源研究所北京大学环境学院北京大学环境学院北京 100101 北京 100871

在东川地区的山地及小江河谷的两侧山麓上部,分布着不同高度和不同规模的层状地貌面,对其成因仍有不同的认识。分歧主要表现在两个方面:一是高原隆升之前的初始地貌面是否是准平原型夷平面;二是山顶面之下的梯级层状地貌面的成因。本文... 详细信息

在东川地区的山地及小江河谷的两侧山麓上部,分布着不同高度和不同规模的层状地貌面,对其成因仍有不同的认识。分歧主要表现在两个方面:一是高原隆升之前的初始地貌面是否是准平原型夷平面;二是山顶面之下的梯级层状地貌面的成因。本文从以下几个方面对上述问题进行讨论:(1)层状地貌面的地貌特征及其与侵蚀河谷体系的关系;(2)层状地貌面上堆积物的性质;(3)层状地貌面与断裂构造水平展布的关系;(4)相邻层状地貌面的空间过渡关系;(5)区域构造演化背景。作者认为在云贵高原抬升过程中,东川地区以挤压穹起隆升变形为主。不同海拔高度的层状地貌面具有多成因特性。山顶面及局部高原面是高原隆升之前古夷平面的残留,并遭到后期强烈的侵蚀改造。目前,尚缺乏足够证据证明高原隆升之前的古夷平面为准平原型夷平面。小江河谷两侧的梯级层状地貌面是侵蚀或剥蚀面,它们形成于高原隆升及初始地貌面解体之后,其梯级空间分布特征与区域性的阶段隆升有关。

关键词：层状地貌面夷平面成因新构造运动小江河谷云贵高原

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与发电联合的新型二甲醚生产流程设计和分析

天然气化工—C1化学与化工 2003年第3期28卷 34-38页

作者：江华倪维斗徐恒泳李政张昊志清华大学热能工程系北京100084 中国科学院大连化学物理研究所大连116023

研究了一种将二甲醚(DME)合成与发电结合的新型流程,它采用甲烷空气催化部分氧化造气、含氮合成气制DME、尾气发电等技术,通过化工生产过程和动力过程的整合,既省去了昂贵的空分设备,又成功地降低了大量氮气带来的负面影响;使用AspenPlu... 详细信息

研究了一种将二甲醚(DME)合成与发电结合的新型流程,它采用甲烷空气催化部分氧化造气、含氮合成气制DME、尾气发电等技术,通过化工生产过程和动力过程的整合,既省去了昂贵的空分设备,又成功地降低了大量氮气带来的负面影响;使用AspenPlus对该联产流程进行了模拟,并在此基础上对新流程的能量和整体性能进行了详细分析,结果表明,在DME生产中使用甲烷空气造气并与发电联合是提高能量转换率和降低DME生产成本的一条新途径。

关键词：二甲醚联产能量分析

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水下光补偿设备对苦草生长生理影响研究

环境科学学报 2024年第3期44卷 450-458页

作者：花炜余成段高旗徐磊张坚彭剑峰苏州科技大学环境科学与工程学院苏州215009 苏州科技大学地理科学与测绘工程学院苏州215009 清华苏州环境创新研究院苏州215163 清华大学环境学院水质与水生态研究中心北京100084 昆山市水务水文调度中心苏州215300

沉水植物苦草(Vallisneria natans L.)作为水生态系统中的重要初级生产者,在治理富营养化水体方面发挥着至关重要的作用.然而,目前关于水下补光的研究主要集中在实验室内,采用LED灯进行实验.在面对水文条件复杂的户外自然环境和受污染... 详细信息

沉水植物苦草(Vallisneria natans L.)作为水生态系统中的重要初级生产者,在治理富营养化水体方面发挥着至关重要的作用.然而,目前关于水下补光的研究主要集中在实验室内,采用LED灯进行实验.在面对水文条件复杂的户外自然环境和受污染水体时,相关的光补偿实验研究相对较少.本文运用一种新型的水下自然光补偿设备,通过设置不同强度的水下光补偿条件:高补光(30.5%自然光)、低补光(15.7%自然光)和对照组(2.8%自然光),研究在户外自然河道条件下苦草幼苗的生长形态、光合作用及抗氧化和毒性胁迫指标.研究发现,与对照组相比,高、低补光组株高分别增加了120%和80%,叶片数分别增加了83.3%和33.3%,叶绿素a含量分别提高了49.4%和30%.实验结果表明,光补偿对苦草幼苗的抗氧化酶活性有显著影响,幼苗对氧化毒性胁迫的抗性平均提升23.9%~48.6%,但光照强度变化对苦草幼苗的可溶性蛋白含量影响并不明显.研究结果可为受污染水体中沉水植物种群恢复提供一定理论依据.

关键词：沉水植物水下光补偿生长形态叶绿素抗氧化毒性胁迫

宁夏草原蝗虫优势种和指示种及其对植被群落的响应

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草地学报 2024年第7期32卷 2005-2017页

作者：曹梓渝张海翔王颖石淳班丽萍张蓉魏淑花宁夏农林科学院植物保护研究所宁夏银川750002 北方民族大学生物科学与工程学院宁夏银川750021 中国农业大学草业科学与技术学院北京100193

为探究宁夏草原蝗虫群落优势种、指示种及其对植被不同类群的响应关系,2019—2020年在宁夏温性草甸草原、温性草原、温性荒漠草原和温性草原化荒漠选取典型调查样地,对不同草原类蝗虫优势种、指示种及其对不同植被群落的响应关系进行了... 详细信息

为探究宁夏草原蝗虫群落优势种、指示种及其对植被不同类群的响应关系,2019—2020年在宁夏温性草甸草原、温性草原、温性荒漠草原和温性草原化荒漠选取典型调查样地,对不同草原类蝗虫优势种、指示种及其对不同植被群落的响应关系进行了分析研究。结果显示:白纹雏蝗(Chorthippus albonemus)作为宁夏四类草原共同优势种,与禾本科和菊科盖度、高度、生物量之间呈显著正相关(P<0.05);短星翅蝗(Calliptamus abbreviatus),亚洲小车蝗(Oedaleus asiaticus)和赤翅皱膝蝗(Angaracris rhodopa)作为温性草原指示种蝗虫,与禾本科植被盖度、频度和生物量呈显著正相关(P<0.05);红缘短鼻蝗(Filchnerella rubimargina)和黑腿星翅蝗(Calliptamus barbarus)作为温性草原化荒漠的优势种,与其他科植被盖度和生物量呈显著负相关关系(P<0.05)。因此,科学监测禾本科与菊科植被分布较广的草原类型将有助于蝗虫有效监测和及时防控,进一步为草原管理和蝗虫可持续治理提供支撑。

关键词：宁夏天然草原草原蝗虫优势种指示种植被响应