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1.
正在湖南省长沙市望城区大泽湖湿地(28°19′14″N,112°53′54″E,海拔40 m)的稻田和草丛中先后3次(2014年3月11日,2015年3月12日和11月9日)分别记录到1只雌性红颈苇鹀(Emberiza yessoensis)(图1)。形态特征如下:头顶具细皮黄色纹,耳羽色深,颈背沙皮黄,下体黄白,胸侧和两胁沾棕色细条纹;虹膜深色,嘴峰直,下嘴厚,嘴及脚均为肉色。  相似文献   

2.
王青锋  王玉国  潘明清   《广西植物》2000,20(1):27-31
莽山自然保护区位于湖南省宜章县境内 (2 4°52′0 0″~ 2 5°0 3′12″N,112°4 3′19″~ 113°0 0′10″E) ,属南岭支脉。作者对该地区水生维管束植物及其生境进行了考察 ,采集到水生沼生维管束植物30科 4 7属 6 7种 ,其中 30种为莽山地区新记录。在比较沼泽和湖泊水生植物群落结构特点的基础上 ,讨论了沼泽作为水生植物重要生境的意义 ,建议对作为珍稀濒危水生植物重要产地的长江以南山地沼泽采取有效的保护措施  相似文献   

3.
攀枝花苏铁   总被引:2,自引:0,他引:2  
1971年,四川省林科所和飞播林场进行植被考查时,发现大片自然苏铁林,地理座标是东经101°33′30″~101°35′38″,北纬26°36′58″~26°38′33″。分布总面积约300多公顷,约12万株,集中在攀枝花市巴关河民政、平江一带,海拔1100~1500m的石灰岩山地、稀树草丛地带,定名为攀枝花苏铁(Cycas Panzhihuaensis)。  相似文献   

4.
IntroductionSudhan Gali is situated at about2100mabovesea level andlies between latitude34°3′35″-34°6′35″andlongitude73°44′30″-70°48′15″.It is60kmawayfromState Capital Muzaffarabad,Kashmir,Pakistan.The highest point of Sudhan Gali is Ganga Choti.Itsheight is about3045m,whichis famous for its fasci-natinglandscape.The soil of Sudhan Gali varies fromclay loamtosandyloamand calcareousin nature.Itis veryshallowon slopes and deep in valley floors.The area has ex-treme climate with…  相似文献   

5.
<正> 马边县是大山区,位于东经103°14′—103°49′40″,北纬28°04′30″—28°24′30″。年平均气温17℃,年降水1,100毫米左右。冬春冷凉干燥、夏秋温暖多雨。 全县耕地面积22万亩,其中稻田3万亩,历年都遭受稻苞虫的为害。1973年稻苞虫特大发生,90%的稻田受害,全县因稻苞虫为害稻谷比1972年减产236万斤。近年来结合预测预报,对稻苞虫进行了如下观察。  相似文献   

6.
胶东海岸的沙生植被   总被引:7,自引:0,他引:7  
胶东半岛位于山东省东部,地处黄、渤海之滨,陆地海岸线全长1668.58km,占山东省陆地海岸线总长的一半以上。海岸地理位置约当北纬36°15′42″—38°24′00″,东经119°33′00″—122°42′18″之间,属暖温带生  相似文献   

7.
本文报道了7种安徽省鸟类分布新纪录,分别为黑脸琵鹭(Platalea minor)、沙丘鹤(Grus canadensis)、黑雁(Branta bernicla)、黄眉姬鹟(Ficedula narcissina)、鳞头树莺(Urosphena squameiceps)、黑眉柳莺(Phylloscopus ricketti)以及红颈苇鹀(Emberiza yessoensis)。其中黑脸琵鹭、沙丘鹤和黑雁是迷鸟,黄眉姬鶲、鳞头树莺和红颈苇鹀是旅鸟,黑眉柳莺是夏候鸟。  相似文献   

8.
通古尔(Tunggur)台地作为20世纪20—30年代美国自然历史博物馆第三中亚考察团研究过的一个经典的脊椎动物化石地点,在亚洲晚新生代陆相哺乳动物学和生物年代学研究中扮演着重要的角色。20世纪90年代中期以来,在通古尔地区开展了大量的野外工作,发现了数个以小型哺乳动物为主的动物群,建立了从早中新世至上新世哺乳动物演化序列的框架。这一框架有可能成为东亚新近纪陆相哺乳动物群对比的标尺。通古尔地区动物群的演替,对于深入认识这一地区古环境和动物地理的分化也十分重要。2005年8月的野外工作,主要在通古尔台地的两个地点——奥尔班和阿勒特希热进行,目的是寻找新生代中晚期的脊椎动物化石和根据古地磁极性年代标尺确定化石的时代。最厚的古地磁采样剖面在奥尔班(Aoerban,43°20′21.6″N,113°54′48.6″E)。取样点起自43°20′36.4″N,113°54′48.6″E,终于43°20′52.7″N,113°54′23.1″E。测试结果显示,剖面上50 m的粘土岩、粉砂岩和细砂岩的互层,除近底部5 m厚的褐棕色粘土岩外均为负极性时。负极性段大致可与国际标准古地磁柱的5Dr或6r对比,相当于18—20 Ma。该剖面上同时进行了小哺乳动物化石的采集;据初步鉴定,化石组合包括了晚渐新世和大量早中新世的成员。因此,奥尔班动物群极有可能代表内蒙古中部地区新近纪哺乳动物群序列中时代最早的一个新成员。阿勒特希热(Aletexire,43°47′21.6″N,113°05′25.0″E)采样剖面始于43°47′53.6″N, 113°04′51.1″E,终于43°47′52.9″N,113°04′42.2″E。剖面厚约13 m,以粉砂岩和细砂岩为主,含有与推饶木动物群相同的成员。测试结果显示,整个剖面记录为正极性时。这便与王晓鸣等于2003年把阿勒特希热剖面古地磁测试的结果与默尔根剖面的对比产生了一些矛盾。原因可能是阿勒特希热的采样间隔过大,或两剖面根本就不是同一时代的产物。同样的问题似乎也出现在与推饶木剖面的对比上。看来有必要对这一地区的古地磁测试作更深入的工作。  相似文献   

9.
黄河上游玛曲县生态环境问题与综合治理对策   总被引:31,自引:0,他引:31  
1 自然地理条件概况玛曲县位于甘肃省西南部 ,10 0°4 5′4 5″~ 10 2°2 9′0 0″E ,33°0 6′30″~ 34°30′15″N ,土地总面积 1 0 19× 10 4 km2 ,是黄河上游以藏民族聚居为主的纯牧业县。阿尼玛卿山、西倾山两大山系主脉形成的西部高山区、中南部阿尼玛卿山东南端和西倾山前山地带丘陵区及黄河沿岸河流阶地构成地形地貌格局[12 ] ,大部分区域海拔 35 0 0~ 380 0m。玛曲属高原大陆性气候 ,年平均气温 1.1℃~2 .7℃ ,年平均降水量 5 0 1.6~ 6 15 .5mm ,主要集中于 5~ 9月 ,年蒸发量 10 0 0~ 15 0 0mm[5] 。年平均风速 2…  相似文献   

10.
洞庭湖区常绿阔叶林的特征与分析   总被引:4,自引:1,他引:3  
一、洞庭湖区常绿阔叶林的生境及自然条件洞庭湖区居荆江南岸,地理位置在北纬28°39′20″至30°14′18″,东经111°42′44″至113°39′45″之间。环湖和湖间丘陵5,044平方公里,占全区总面积的26.86%,其间保存有天然次生林106万亩。环湖和湖间丘陵多属低丘波状台地,除个别低山外,海拔多在350米以下。基岩由浅变质岩、砂页岩、石英砂岩、局部花岗岩体和厚层的第四纪红壤所组成。林地有机质含量一般在2—3%,全氮含量0.075—0.15%,速效氮、磷、钾含量为60  相似文献   

11.
12.
Curcumin is the yellow pigment of turmeric that interacts irreversibly forming an adduct with thioredoxin reductase (TrxR), an enzyme responsible for redox control of cell and defence against oxidative stress. Docking at both the active sites of TrxR was performed to compare the potency of three naturally occurring curcuminoids, namely curcumin, demethoxy curcumin and bis-demethoxy curcumin. Results show that active sites of TrxR occur at the junction of E and F chains. Volume and area of both cavities is predicted. It has been concluded by distance mapping of the most active conformations that Se atom of catalytic residue SeCYS498, is at a distance of 3.56 from C13 of demethoxy curcumin at the E chain active site, whereas C13 carbon atom forms adduct with Se atom of SeCys 498. We report that at least one methoxy group in curcuminoids is necessary for interation with catalytic residues of thioredoxin. Pharmacophore of both active sites of the TrxR receptor for curcumin and demethoxy curcumin molecules has been drawn and proposed for design and synthesis of most probable potent antiproliferative synthetic drugs.  相似文献   

13.
正Dear Editor,In December 2019, a novel human coronavirus caused an epidemic of severe pneumonia(Coronavirus Disease 2019,COVID-19) in Wuhan, Hubei, China(Wu et al. 2020; Zhu et al. 2020). So far, this virus has spread to all areas of China and even to other countries. The epidemic has caused 67,102 confirmed infections with 1526 fatal cases  相似文献   

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The young pistils in the melanthioid tribes, Hewardieae, Petrosavieae and Tricyrteae, are uniformly tricarpellate and syncarpous. They lack raphide idioblasts. All are multiovulate, with bitegmic ovules. The Petrosavieae are marked by the presence of septal glands and incomplete syncarpy. Tepals and stamens adhere to the ovary in the Hewardieae and the Petrosavieae but not in the Tricyrteae. Two vascular bundles occur in the stamens of the Hewartlieae and Tricyrtis latifolia. Ventral bundles in the upper part of the ovary of the Hewardieae are continuous with compound septal bundles and placental bundles in the lower part. Putative ventral bundles occur in the alternate position in the Tricyrteae and putative placental bundles in the opposite. position in the Petrosavieae. The dichtomously branched stigma in each carpel of the Tricyrteae is supplied by a bifurcated dorsal bundle.  相似文献   

17.
Some closely related members of the monocotyledonous familiesAlismataceae, Liliaceae, Juncaceae, Cyperaceae, Poaceae andAraceae with variable modes of pollination (insect- and wind-pollination) were studied in relation to the ultrastructure of pollenkitt and exine (amount, consistency and distribution of pollenkitt on the surface of pollen grains). The character syndromes of pollen cementing in entomophilous, anemophilous and intermediate (ambophilous or amphiphilous) monocotyledons are the same in principal as in dicotyledons. Comparing present with former results one can summarize: 1) The pollenkitt is always produced in the same manner by the anther tapetum in all angiosperm sub-classes. 2) The variable stickiness of entomophilous and anemophilous pollen always depends on the particular distribution and consistency of the pollenkitt, but not its amount on the pollen surface. 3) The mostly dry and powdery pollen of anemophilous plants always contains a variable amount of inactive pollenkitt in its exine cavities. 4) A step-by step change of the pollen cementing syndrome can be observed from entomophily towards anemophily. 5) From the omnipresence of pollenkitt in all wind-pollinated angiosperms studied one can conclude that the ancestors of anemophilous angiosperms probably have been zoophilous (i.e. entomophilous) throughout.
  相似文献   

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19.
正Dear Editor,Parainfluenza virus 5 (PIV5), known as canine parainfluenza virus in the veterinary field, is a negative-sense,nonsegmented, single-stranded RNA virus belonging to the Paramyxoviridae family (Chen 2018). The virus was first reported in primary monkey kidney cells in 1954 (Hsiung1972), then it has been frequently discovered in various  相似文献   

20.
<正>Dear Editor,Infectious bursal disease (IBD) is one of the most important diseases of the poultry. The IBD virus (IBDV), a nonenveloped virus belonging to the Birnaviridae family with a genome consisting of two segments of double-stranded RNA (segments A and B), targets B lymphocytes of bursa of Fabricious leading to immunosuppression. In Pakistan,poultry farming is the second biggest industry and IBD is the second biggest disease threating the poultry sector.However, there is limited genome information of IBDV  相似文献   

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