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南极生物粪对汞的生物放大作用 被引量:7
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作者 尹雪斌 孙立广 +1 位作者 刘晓东 朱仁斌 《生态学报》 CAS CSCD 北大核心 2004年第3期630-634,共5页
首次报道了南极地区金图企鹅、阿德利企鹅、黑背鸥和巨海燕 4种海鸟 ,以及象海豹、威德尔海豹、毛皮海狮等 3种海豹新鲜粪便中的全 Hg含量 ,并对比了该区风化土壤的 Hg含量 ,其中 Hg含量水平依次为 :土壤背景值 <黑背鸥粪 <金图... 首次报道了南极地区金图企鹅、阿德利企鹅、黑背鸥和巨海燕 4种海鸟 ,以及象海豹、威德尔海豹、毛皮海狮等 3种海豹新鲜粪便中的全 Hg含量 ,并对比了该区风化土壤的 Hg含量 ,其中 Hg含量水平依次为 :土壤背景值 <黑背鸥粪 <金图企鹅粪 <阿德利企鹅粪 <威德尔海豹粪 <象海豹粪 <巨海燕粪 <毛皮海狮粪 ,可见 ,相对于背景土壤生物粪明显富集 Hg元素。此外 ,结合上述粪便样品的 δ15 N测定结果 ,讨论了南极生物粪对 Hg的生物放大作用。研究表明 ,随着 δ15 N升高 ,即生物营养级的升高 ,其粪便的全 Hg含量有逐步增高的趋势 ,这证实了生物粪和生物肌体一样存在对 Hg的生物放大作用。文中还对南极阿德雷岛一个经过企鹅粪污染的 Y2湖泥芯剖面上 15个样品的 2 6种元素进行了聚类分析 ,结果表明 ,沉积物中的汞和企鹅粪的标型元素具有同源性 ,即沉积物中的汞主要是由企鹅粪带入的 ,由于生物粪对汞的生物富集作用 。 展开更多
关键词 南极地区 生物粪 生物放大 生物富集 企鹅 湖泊沉积物 重金属污染
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CFOSAT-1 Realizes First Joint Observation of Sea Wind and Waves 被引量:3
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作者 WANG Lili DING Zhenyu +1 位作者 ZHANG Lei YAN Cheng 《Aerospace China》 2019年第1期20-27,共8页
The Chinese-French Oceanic Satellite 1(CFOSAT-1) was successfully launched on October 29, 2018. The satellite was developed under cooperation between China and France. CFOSAT-1 realizes joint observation of sea waves ... The Chinese-French Oceanic Satellite 1(CFOSAT-1) was successfully launched on October 29, 2018. The satellite was developed under cooperation between China and France. CFOSAT-1 realizes joint observation of sea waves and wind for the first time in the world. This paper introduces the background of the satellite, including application goals and the division of the project. The paper describes the satellite platform composition, the coverage and benefit of conducting joint observation as well as the working principle, structure and performance of the two payloads, SCAT and SWIM, and introduces the in-orbit observation results of sea wind and waves. The difficulties during the development, solutions and acquired experience for future international space cooperation are also introduced. Finally, the conclusion concerning CFOSAT-1's contributions to sea state forecast, marine and climate research, as well as its important role in the ocean dynamic environment detection system. 展开更多
关键词 CFOSAT-1 WIND WAVES OCEAN dynamics scat SWIM
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Eurasian otters prefer to prey on religious released nonnative fish on the Qinghai-Tibetan Plateau
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作者 Qiaoyun Wang Xuesong Han +5 位作者 Zichen Wang Kaidan Zheng Zhengyi Dong Peng Zhang Pengfei Fan Lu Zhang 《Current Zoology》 SCIE CAS CSCD 2024年第4期472-479,共8页
Religious wildlife release is prevalent worldwide,especially in Asia countries.It is one of the anthropogenic pathways to cause biological inva-sions.Religious fish release is common on the Qinghai-Tibetan Plateau,yet... Religious wildlife release is prevalent worldwide,especially in Asia countries.It is one of the anthropogenic pathways to cause biological inva-sions.Religious fish release is common on the Qinghai-Tibetan Plateau,yet few studies have assessed the influences of religious fish release on local species.InYushu,a city on the Qinghai-Tibetan Plateau,we interviewedlocal people,conducted fish trap surveys in local rivers,and exam-ined the diet of Eurasian otters Lutra lutra using a fecal DNA metabarcoding approach.We found that fish release started at least in 1980-1990s in Yushu.Tibetan residents released fish in large amounts and released fish were usually exotic commercial fish purchased from market.Despite such long-term and intensive fish release activities,released fish were few in local rivers.On the other hand,Eurasian otters mainly prey on fish and released fish accounted for~20%of relative read abundance of prey DNA in otters'diet,indicating their high preference on released fish.Our study suggested that religious fish release may provide additional food resources for otters,whereas otters,as a top predator in local rivers,may deplete non-native fish once they were released and,therefore,reduce the probability of colonization of released fish,although further studies are required to assess otters'impact.Our study revealed otters'diet in Yushu,providing basic information for local otter management and conservation.Furthermore,it represents a case showing that native predators prey on religious released animals,implying a probable direction forcontrolling invasive species through nativepredator conservation. 展开更多
关键词 biological invasion BUDDHISM Eurasian otter prey composition religious wildlife release scat DNA.
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基于粪便分析的大型食肉动物食性研究方法概述
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作者 赵筱涛 刘文静 窦海龙 《曲阜师范大学学报(自然科学版)》 CAS 2024年第1期101-106,共6页
文章通过查阅大量相关文献,对基于粪便分析的大型陆生食肉动物食性研究方法进行了综述,对食性研究揭示及解决的科学问题进行了系统的总结,以期为从事相关研究的学者提供参考.
关键词 大型食肉动物 食性 粪便
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A comparison of food habits and prey preferences of Amur tiger(Panthera tigris altaica)at the southwest Primorskii Krai in Russia and Hunchun in China 被引量:3
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作者 Jiayin GU Lan YU +10 位作者 Yan HUA Yao NING Bao HENG Jinzhe QI Zexv LONG Mingyuan YAO Chong HUANG Zhilin LI Jianming LANG Guangshun JIANG Jianzhang MA 《Integrative Zoology》 SCIE CSCD 2018年第5期595-603,共9页
A small,isolated Amur tiger population ranges across the southwest Primorskii Krai region in Russia and Hunchun region in China.Many individuals,with“dual nationality,”cross the border frequently.Formulating effecti... A small,isolated Amur tiger population ranges across the southwest Primorskii Krai region in Russia and Hunchun region in China.Many individuals,with“dual nationality,”cross the border frequently.Formulating effective conservation strategies requires a clear understanding of tiger food requirements in both countries.While the diets of tigers ranging in Russia is clearly understood,little is known of the tigers’feeding habits in China..We used scat analysis combined with data on the abundance of 4 prey species to examine Amur tiger diet and prey preferences in Hunchun.We examined 53 tiger scat samples from 2011 to 2016 and found that tigers preyed on 12 species(11 species in winter),4 of which were domestic animals with 33.58%biomass contribution;this was the first record of Amur tigers eating lynx in this area.Tigers showed a strong preference for wild boar(Jacobs index:+0.849),which were also the most frequently consumed prey,and a strong avoidance of roe deer(Jacobs index:–0.693).On the Russian side,domestic animals(just dog)were rarely found in tiger scat,and tigers did not show strong avoidance of roe deer,but of sika deer.We also found red deer footprints during winter surveys and that tigers ate red deer on the Chinese side,while there was no record of red deer feeding on the Russian side.Reducing or eliminating human disturbance,such as grazing,is essential to recovering tiger prey and habitat in this area and the Sino–Russian joint ungulate annual survey is indispensable for prey estimates of this small,isolated Amur tiger population. 展开更多
关键词 Amur tiger food habitat prey preference scat analysis southwest Primorie-Hunchun
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Food habits of striped hyena(Hyaena hyaena) in a semi-arid conservation area of India
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作者 M Shamshad ALAM Jamal A KHAN 《Journal of Arid Land》 SCIE CSCD 2015年第6期860-866,共7页
Striped hyena(Hyaena hyaena) is a near-threatened large carnivore known to occur in arid and semi-arid landscapes in many parts of the world. Its population is declining globally and ecological information is requir... Striped hyena(Hyaena hyaena) is a near-threatened large carnivore known to occur in arid and semi-arid landscapes in many parts of the world. Its population is declining globally and ecological information is required urgently to meet their conservation needs. We studied the diet pattern of the striped hyena in the semi-arid Gir National Park and Sanctuary(GNPS), western India. Prey items eaten by the striped hyena were identified from scats. Around 44.4% scats represented single to three mammalian preys while 55.6% of them represented four preys to seven preys. A variety of food items were identified including mammals, birds, insects and vegetable matters. Scats analysis showed that 63.91% diet of striped hyena was contributed by wild prey items, 20.94% by domestic prey and 3.31% by birds, whereas vegetable and insects contributed 9.92% and 1.93%, respectively. Diet diversity of the striped hyena computed by the Shannon-Weiner Index(H) was found to be 2.64. The presence of domestic mammals in the scat remains implied that the striped hyena might frequently visit human habitation in search for food and hence, a potential conflict between human and wildlife might arise. Reducing the dependence of hyena on domestic livestock is a challenge to ensure the survival of striped hyena outside the protected area. 展开更多
关键词 diet pattern Gir National Park and Sanctuary Hyaena hyaena scat analysis
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Engine valve and seat insert wear study with a simulator
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作者 Y.S.Wang S.Narasimhan 《Science China Mathematics》 SCIE 2001年第S1期235-241,共7页
The demands on higher performance and the increasing use of alternative fuels chal-lenge engine valves now with greater wear problems than before. A seat wear simulator was builtto evaluate the compatibility and wear ... The demands on higher performance and the increasing use of alternative fuels chal-lenge engine valves now with greater wear problems than before. A seat wear simulator was builtto evaluate the compatibility and wear of valve and seat insert. The rig test results have been suc-cessfully correlated with engine test results. In this study, intake valves made from Sil 1 materialwere treated with salt bath nitride processes and tested against six different insert materials. Wearresistance of these combinations was ranked and compared to the Sil 1 valve without nitriding.The test results demonstrate that nitriding improved valve seat wear resistance. In the total valveseat recession ranking, the combination of nitrided Sil 1 valve against T 400 insert exhibited theleast total recession among the nineteen combinations of valve and insert tested. The results indi-cate that the valve seat wear mechanisms are a complex combination of adhesion and shearstrain. The nitrides in the compound layer of nitrided valves gave strong atomic bonding, higherhardness, compressive residual stresses, and possible low friction, thus resulted in the superiorwear performance. 展开更多
关键词 ENGINE VALVE nitride SEAT INSERT VALVE scat WEAR mechanism WEAR simulation
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基于QuikSCAT资料的江淮流域旱涝年南海季风变化特征 被引量:2
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作者 连帆 巩远发 +1 位作者 刘佩佩 万超 《热带气象学报》 CSCD 北大核心 2014年第6期1137-1145,共9页
利用2001、2003年的Quik SCAT风场和中国降水的逐日资料,分析江淮流域旱、涝年南海夏季风的演变特征及其低频分量与江淮流域降水的关系。结果表明:(1)2001、2003年南海夏季风爆发时间相当,但2003年6月中下旬季风出现明显的中断,2001年6... 利用2001、2003年的Quik SCAT风场和中国降水的逐日资料,分析江淮流域旱、涝年南海夏季风的演变特征及其低频分量与江淮流域降水的关系。结果表明:(1)2001、2003年南海夏季风爆发时间相当,但2003年6月中下旬季风出现明显的中断,2001年6—7月南海季风表现出明显的由南海中南部向北部推进的过程,而2003年同时期的季风则徘徊于南海中南部地区;(2)2001、2003年的夏季(5—9月)海表面的低频纬向风场同时都存在3对低频振荡中心,且在季风爆发后均有明显的向北传播特征,南海中部和北部表现出近乎相反的低频位相,但2001年低频振荡的强度及低频波列维持的时间均大于2003年的;(3)根据纬向风低频振荡强中心区域的位置,在南海中部和北部分别定义了南海低频夏季风指数IM-SCS和IN-SCS,发现这两个指数与我国6—7月江淮流域的降水及青藏高原中东部降水之间均存在显著的滞后负相关关系,而与云南中部、西部及华北部分地区的降水则表现出显著的滞后正相关关系。 展开更多
关键词 Quik scat 南海季风 江淮流域旱涝 低频振荡
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CDFI及CTA在颈动脉重度狭窄患者术前诊断及术后随访中的应用 被引量:1
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作者 秦冉 王莉莉 鲍巍 《现代医用影像学》 2022年第8期1572-1575,共4页
目的:探讨颈部血管超声血流显像(CDFI)及CT血管造影(CTA)在颈动脉重度狭窄(SCAT)患者术前诊断及术后随访中的应用。方法:选择2020年1月到2021年6月期间于我院接受检查的87例颈动脉狭窄患者作为观察对象,所有患者均接受颈动脉内膜剥脱术(... 目的:探讨颈部血管超声血流显像(CDFI)及CT血管造影(CTA)在颈动脉重度狭窄(SCAT)患者术前诊断及术后随访中的应用。方法:选择2020年1月到2021年6月期间于我院接受检查的87例颈动脉狭窄患者作为观察对象,所有患者均接受颈动脉内膜剥脱术(CEA)治疗,在术前及术后均进行数字减影血管造影(DSA)、CDFI、CTA检查。记录术前及术后6个月CTA与CDFI检查参数、不同检查手段的诊断结果,并以DSA为金标准,对比CTA与CDFI诊断SCAT的一致性与诊断效能。结果:术后6个月患者的狭窄段收缩期峰值血流速度(PSV)、舒张末期血流速度(EDV)均较术前低,狭窄远端的直径、最小残余直径均较术前大。共87例患者,金标准检出SCAT 65例,非重度狭窄22例;CTA、CDFI均检出SCAT 61例,非重度狭窄26例。CDFI的诊断结果与金标准对比有高度一致性,Kappa值为0.713,P<0.001;CTA的诊断结果与金标准对比有高度一致性,Kappa值为0.828,P<0.001。CTA与CDFI诊断SCAT的敏感度、特异度、准确度、阳性预测值(PPV)、阴性预测值(NPV)对比无统计学差异(P>0.05)。结论:CDFI、CTA诊断SCAT情况的效能相当,与金标准的一致性高,均可用于指导患者行CEA手术和术后随访检查。 展开更多
关键词 颈部血管超声血流显像 CT血管造影 scat 数字减影血管造影
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护理技能竞赛选手气质类型与竞赛焦虑状况研究
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作者 李赢 陈欢 任森 《临床心身疾病杂志》 CAS 2014年第1期38-40,46,共4页
目的:了解护理技能竞赛选手的气质类型及其竞赛焦虑状况,为护理技能竞赛选手的心理选拔提供理论依据。方法将374名护理专业学生按是否参加护理技能竞赛分为选手组(50名)和非选手组(324名),采用气质类型测验问卷和运动竞赛焦虑测... 目的:了解护理技能竞赛选手的气质类型及其竞赛焦虑状况,为护理技能竞赛选手的心理选拔提供理论依据。方法将374名护理专业学生按是否参加护理技能竞赛分为选手组(50名)和非选手组(324名),采用气质类型测验问卷和运动竞赛焦虑测验进行测评分析。结果不同气质类型学生的运动竞赛焦虑测验评分比较差异有显著性(P<0.05)。选手组运动竞赛焦虑测验评分显著低于非选手组(P<0.01),两组气质类型分布比较差异有显著性(P<0.05),选手组气质类型以多血质、多血-粘液质及粘液质为主(74.0%)。结论护理技能竞赛选手竞赛焦虑水平较低,气质类型以多血质或粘液质为主。 展开更多
关键词 护理技能竞赛 竞赛选手 竞赛焦虑 气质类型 心身健康 气质类型测验问卷 运动竞赛焦虑测验
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Study on Raman and SERS spectra of filter paper and silica gel plate
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作者 欧阳雨 《Journal of Measurement Science and Instrumentation》 CAS 2012年第4期313-316,共4页
Raman spectra and surface-enhanced Raman scattering (SERS) spectra of filter paper and silica gel plate are ob- tained at 785-nm excitation wavelength. The results show that filter paper has thirteen Raman lines in ... Raman spectra and surface-enhanced Raman scattering (SERS) spectra of filter paper and silica gel plate are ob- tained at 785-nm excitation wavelength. The results show that filter paper has thirteen Raman lines in 800 - 1 500 cm 1 and silica gel plate has eight lines in the region of 400 - 1 200 cm-I. The frequencies and Raman active modes are assigned. By comparing their Raman spectra and SERS spectra, we find that the silver colloid could repress the Raman intensities of filter paper and silica gel plate, and reduce their effects on the combination of thin-layer chromatographic (TLC) and SERS. Ac- cording to SERS spectra, the bands at 997 cm 1,1 094 cm I ,1 118 cm-1 ,1 336 cm-1 and 1 378 cm-1 for filter paper and the peak of v l [ SO4] symmetric stretching vibration (--1 017 cm-1 ) for silica gel plate also have high intensities, and those lines should be paid enough attention in TLC-SERS. 展开更多
关键词 hromatography paper chromatography silica gel plate Raman spectroscopy Surface-enhenced Raman scat- tering(SERS)
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水溶性游离碱阳离子卟啉与核酸作用的光谱研究 被引量:44
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作者 黄承志 李克安 童沈阳 《高等学校化学学报》 SCIE EI CAS CSCD 北大核心 1997年第4期525-529,共5页
研究了meso-四(对-三甲基氨基本基)卟啉(TAPP)和meso-四(对-甲基吡啶基)卟啉(TMPyP-4)与核酸作用的电子吸收光谱、荧光光谱和共振光散射光谱的特性.电子吸收和荧光光谱研究表明,这两个水溶性阳离子卟啉与核酸的摩尔比(... 研究了meso-四(对-三甲基氨基本基)卟啉(TAPP)和meso-四(对-甲基吡啶基)卟啉(TMPyP-4)与核酸作用的电子吸收光谱、荧光光谱和共振光散射光谱的特性.电子吸收和荧光光谱研究表明,这两个水溶性阳离子卟啉与核酸的摩尔比(R)大于0.25时,核酸对卟啉的Soret带都有减色效应和荧光碎灭效应;当R<0.25时,核酸与卟啉作用形成新的荧光复合物.共振光散射光谱研究表明,核酸使TAPP的共振光散射增强,但对TMyyP-4的共振光散射信号无影响. 展开更多
关键词 核酸 荧光光谱 卟啉 TMpyP-4 TAPP DNA RNA
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金钱鱼生物学研究及回顾 被引量:32
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作者 兰国宝 阎冰 +2 位作者 廖思明 罗砚 谢若痴 《水产科学》 CAS 北大核心 2005年第7期39-41,共3页
关键词 金钱鱼 分布 食性 生长 繁殖 养殖 人工繁殖
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麦冬多糖单糖组成的分析方法研究: 被引量:26
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作者 胡坪 乔晚芳 +4 位作者 沈骏文 张弛 章弘扬 张敏 王月荣 《药物分析杂志》 CAS CSCD 北大核心 2013年第1期50-56,共7页
目的:建立一种麦冬多糖中单糖组成的高效液相色谱(HPLC)-蒸发光散射(ELSD)测定方法。方法:以三氟乙酸(TFA)水解麦冬多糖,采用Waters XBridgeTMAmide色谱柱,乙腈-水-三乙胺(75∶25∶0.2)为流动相,ELSD检测器监测麦冬多糖的酸水解产物,优... 目的:建立一种麦冬多糖中单糖组成的高效液相色谱(HPLC)-蒸发光散射(ELSD)测定方法。方法:以三氟乙酸(TFA)水解麦冬多糖,采用Waters XBridgeTMAmide色谱柱,乙腈-水-三乙胺(75∶25∶0.2)为流动相,ELSD检测器监测麦冬多糖的酸水解产物,优化麦冬多糖的全水解条件,并对麦冬多糖的单糖组成进行分析。结果:麦冬多糖由果糖和葡萄糖组成,其全水解条件为以0.02 mol·L-1TFA为水解试剂,在110℃下水解2 h。HPLC-ELSD方法验证结果表明,该单糖组成测定方法的精密度和重复性良好,果糖和葡萄糖的加样回收率分别为95.9%~104.4%和91.3%~104.1%(RSD<5.9%)。麦冬多糖中果糖和葡萄糖的摩尔比约为15∶1。结论:本研究为麦冬多糖中单糖组成的准确测定提供了方法。 展开更多
关键词 麦冬多糖 高效液相色谱-蒸发光散射检测器 全水解 方法学验证 单糖组成 果糖测定
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Quantum superposition, entanglement, and state teleportation of a microorganism on an electromechanical oscillator 被引量:17
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作者 Tongcang Li Zhang-Qi Yin 《Science Bulletin》 SCIE EI CAS CSCD 2016年第2期163-171,共9页
Schrodinger's thought experiment to prepare a cat in a superposition of both alive and dead states reveals profound consequences of quantum mechanics and has attracted enormous interests. Here we propose a straight- ... Schrodinger's thought experiment to prepare a cat in a superposition of both alive and dead states reveals profound consequences of quantum mechanics and has attracted enormous interests. Here we propose a straight- forward method to create quantum superposition states of a living microorganism by putting a small cryopreserved bacterium on top of an electromechanical oscillator. Our proposal is based on recent developments that the center- of-mass oscillation of a 15-pro-diameter aluminum mem- brane has been cooled to its quantum ground state (Teufel et al. in Nature 475:359, 2011), and entangled with a microwave field (Palomaki et al. in Science 342:710, 2013). A microorganism with a mass much smaller than the mass of the electromechanical membrane will not signifi- cantly affect the quality factor of the membrane and can be cooled to the quantum ground state together with themembrane. Quantum superposition and teleportation of its center-of-mass motion state can be realized with the help of superconducting microwave circuits. More importantly, the internal states of a microorganism, such as the electron spin of a glycine radical, can be entangled with its center-of- mass motion and teleported to a remote microorganism. Our proposal can be realized with state-of-the-art tech- nologies. The proposed setup is a quantum-limited mag- netic resonance force microscope. Since internal states of an organism contain information, our proposal also pro- vides a scheme for teleporting information or memories between two remote organisms. 展开更多
关键词 Quantum superposition Quantumentanglement Quantum teleportation Schrodinger'scat Electromechanical Oscillator Cryopreservedmicroorganism
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藏借阅一体化管理模式下的抢占座位现象 被引量:12
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作者 贾成娟 韦成礼 《农业图书情报学刊》 2005年第10期55-57,共3页
随着高校招生规模的不断扩大和图书馆环境的改变,图书馆资源与读者的需求矛盾日益突出,“抢占座位”的出现就是矛盾激化的体现。本文通过对“抢占座位”现象的分析,提出一些解决的办法。
关键词 图书馆 藏借阅一体化 管理模式 抢占座位 分析
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三江源和祁连山国家公园雪豹种群的遗传结构分析 被引量:12
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作者 张于光 Charlotte Hacker +7 位作者 张宇 薛亚东 乌力吉 代云川 罗平 谢然尼玛 Jan E Janecka 李迪强 《兽类学报》 CAS CSCD 北大核心 2019年第4期442-449,共8页
掌握遗传信息对濒危物种的保护和管理具有重要意义。本研究在我国雪豹重要分布区祁连山和三江源国家公园分别采集粪便样品,利用mtDNA的cyt b基因、微卫星多态性位点进行了雪豹的物种鉴定、个体识别和种群遗传结构评估。在采集286份疑似... 掌握遗传信息对濒危物种的保护和管理具有重要意义。本研究在我国雪豹重要分布区祁连山和三江源国家公园分别采集粪便样品,利用mtDNA的cyt b基因、微卫星多态性位点进行了雪豹的物种鉴定、个体识别和种群遗传结构评估。在采集286份疑似雪豹粪便样品中,成功的对86份雪豹样品进行了扩增鉴定,利用微卫星位点进行个体识别获得41只雪豹个体,其中祁连山国家公园26只,三江源国家公园15只。通过等位基因数、有效等位基因数、观测杂合度、期望杂合度、多态信息含量等指标进行种群遗传多样性评估,认为雪豹种群遗传多样性相对较低,但祁连山国家公园雪豹种群遗传多样性相对较高。STRUCTURE进行群体遗传结构分析表明,4个种群可以划分为3个遗传类群,祁连山国家公园的种群(YCW和QLS)与三江源国家公园种群(DC和SJ)的遗传差异,可能与种群间的地理隔离存在明显的相似性。 展开更多
关键词 遗传多样性 微卫星标记 线粒体cyt B基因 粪便DNA技术
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激光散射法测定催化裂化催化剂粒度分布的影响因素 被引量:8
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作者 郭瑶庆 朱玉霞 +1 位作者 宿艳芳 罗宇屏 《石油炼制与化工》 CAS CSCD 北大核心 2005年第3期55-59,共5页
考察了激光散射法测定裂化催化剂粒度分布的影响因素,诸如样品的分散处理方式、测量时间、搅拌速度、遮光度及计算理论的选择等,从而确定了分析条件,即不超声分散,遮光度在13%~18%范围内,搅拌泵速2500r/min,测量时间10s。分析结果表明... 考察了激光散射法测定裂化催化剂粒度分布的影响因素,诸如样品的分散处理方式、测量时间、搅拌速度、遮光度及计算理论的选择等,从而确定了分析条件,即不超声分散,遮光度在13%~18%范围内,搅拌泵速2500r/min,测量时间10s。分析结果表明,催化裂化催化剂经超声分散处理易导致测量结果偏小,采用Mie理论计算模型可以减少分析结果的差异。 展开更多
关键词 超声分散 粒度分布 搅拌速度 测量时间 光度 激光散射法 催化裂化催化剂 测量结果
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天麻钩藤饮对轻型颅脑损伤患者脑保护作用的临床研究 被引量:6
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作者 张昕 黄李法 +3 位作者 寿迪文 李徐 陈祖鹏 杨超 《浙江医学》 CAS 2018年第6期557-559,共3页
目的探讨天麻钩藤饮对轻型颅脑损伤(m TBI)患者的脑保护作用。方法选取m TBI患者73例并按单双号分为两组,对照组采用常规西药治疗(谷维素10mg+吡拉西坦0.8g/次,3次/d),天麻钩藤饮组(研究组)采用常规西药联用天麻钩藤饮治疗(5g/次,3次/d)... 目的探讨天麻钩藤饮对轻型颅脑损伤(m TBI)患者的脑保护作用。方法选取m TBI患者73例并按单双号分为两组,对照组采用常规西药治疗(谷维素10mg+吡拉西坦0.8g/次,3次/d),天麻钩藤饮组(研究组)采用常规西药联用天麻钩藤饮治疗(5g/次,3次/d),治疗疗程为2周。分别检测治疗前、治疗后第3、7、10、14天血清S-100β、IL-6、TNF-α水平及第2代运动脑震荡评估量表(SCAT-2)评分、标准化脑震荡评分量表(SAC)评分。结果治疗第3、7、10、14天两组血清S-100β、IL-6、TNF-α水平逐渐降低,但研究组数值与对照组比较有统计学差异,下降值更大;同时点的SCAT-2、SAC量表评分表明,研究组上升分值高于对照组,患者病情好转程度高于对照组。结论天麻钩藤饮可减轻mTBI患者的炎症反应产生脑保护作用,值得在临床推广应用。 展开更多
关键词 天麻钩藤饮 轻型脑外伤 scat-2量表
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基于微多普勒估计进动锥体目标特征参数 被引量:8
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作者 束长勇 张生俊 +1 位作者 黄沛霖 姬金祖 《系统工程与电子技术》 EI CSCD 北大核心 2017年第1期15-20,共6页
锥体目标时频分布是目标的微动及结构信息的联合表征,针对此提出了一种利用微多普勒估计进动锥体目标特征参数的方法。首先分析了进动锥体目标散射源微多普勒的理论解,并利用三角函数降幂公式将其归纳整理为多阶谐波分量的合成,然后利... 锥体目标时频分布是目标的微动及结构信息的联合表征,针对此提出了一种利用微多普勒估计进动锥体目标特征参数的方法。首先分析了进动锥体目标散射源微多普勒的理论解,并利用三角函数降幂公式将其归纳整理为多阶谐波分量的合成,然后利用目标跟踪技术获取了不同散射源的微多普勒,最后依据锥顶及锥底不同谐波分量与目标特征参数的关系,提出了一种特征参数的估算方法。可为空间进动锥体目标识别提供一定参考。 展开更多
关键词 目标识别 进动锥体目标 微多普勒 参数估计 强散射源
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