内蒙古锡林河流域羊草草原生态系统碳素循环研究

采用野外调查和模型预测方法相结合,对内蒙古锡林河流域一个永久试验样地内的羊草（Ｌｅｙｍｕｓｃｈｉｎｅｎｓｉｓ（Ｔｒｉｎ．）Ｔｚｖｅｌ．）草原群落的碳素贮量、主要流量和周转速度等进行了初步估计,研究了长期过度放牧对整个流域羊草草原土壤有机碳贮量的影响。结果表明：１）羊草群落净初级生产固碳量的多年实测平均值为（２３１．２５±７４．４１）ｇＣ·ｍ－２·ａ－１,向土壤中的碳素输入量为２２０．７５ｇＣ·ｍ－２·ａ－１,土壤呼吸量的模型预测值为（１８１．０３±４６．３２）ｇＣ·ｍ－２·ａ－１;２）该群落碳素输入略大于输出,其理论积累率为１９．８８ｇＣ·ｍ－２·ａ－１,实测积累率为３９．７２ｇＣ·ｍ－２·ａ－１;３）近４０年来,过度放牧致使锡林河流域羊草草原表层（０～２０ｃｍ）土壤的有机碳贮量下降了约１２．４％。     

扁担塘螺类生产力的研究Ⅰ.铜锈环棱螺的周年生产量

１９９６—１９９７年对扁担塘螺类优势种之一铜锈环棱螺进行了周年研究,结果表明其种群含四个年龄组,其中１９９６年组生长最快,其带壳湿重瞬时生长率为４．１５,去壳干重瞬时生长率为３．４０。采用瞬时生长率法测算其周年生产量为：带壳湿重,１５．７７ｇ·ｍ－２·ａ－１;去壳干重,０．８６２４ｇ·ｍ－２·ａ－１。Ｐ／Ｂ系数基本一致,分别为０．５０,０．５１。铜锈环棱螺的生产量的去壳干重（Ｗｄ,ｇ·ｍ－２·ａ－１）和带壳湿重（Ｗｗ,ｇ·ｍ－２·ａ－１）满足下列关系：Ｗｗ＝１７．２０Ｗｄ。     

淤泥湖退化水生植被恢复及其在湖泊资源天然生态库中作用的研究

对淤泥湖水生植被的天然恢复过程、群落组成、结构、功能与动态等进行了定位研究（１９９２～１９９５）．该湖水生植物共有２０科２９属４１种．４种生活型的植物种类在该湖均有分布,以沉水草本（１５种）和挺水草本（１３种）为多．８个分布区类型中世界广布成分１６种和东亚成分１０种．群落结构包括层次结构和层片结构．该彻共有８个群落类型;群落现存量３２０８．８ｇ·ｍ－２,全湖植被资源贮量为１６３６５．２ｔ．     

鹤山南亚热带草坡生态系统的生物量和生产力研究

以能量利用效率研究为中心,系统研究并分析了鹤山南亚热带草坡多年的光合作用与总第一性生产力、生物量与生物量增量、气候生产力模型和能量利用效率等能量学特征。草坡的总生物量为１１．３０ｔ·（ｈｍ）－２·ａ－１,其生物量增量为１．３９８ｔ·（ｈｍ）－２·ａ－１;草坡的总第一性生产力为４５．５４ｔ·（ｈｍ）－２·ａ－１,净第一性生产力为９．１０８ｔ·（ｈｍ）－２·ａ－１,用于净光合作用耗热１０５．５ＭＪ·ｍ－２·ａ－１,净光合耗热中又仅有２１．１ＭＪ·ｍ－２·ａ－１,用于净第一性生产力,净第一性生产力中又仅有３．２４ＭＪ·ｍ－２·ａ－１用于生物量增量;草坡生态系统的光能利用效率为０．０７％。草坡的能量利用效率是很低的     

长白山北坡不同土壤N2O和CH4排放的初步研究

用箱法技术原位测定了长白山北坡不同土壤（苔原土、生草森林土、棕色针叶林土和暗棕色森林土）６—８月间的Ｎ２Ｏ和ＣＨ４排放．结果表明,这些土壤既是Ｎ２Ｏ的源,又同时是ＣＨ４的汇．Ｎ２Ｏ通量变化于６．１７—１２．３３μｇ·ｍ－２·ｈ－３之间（平均９．３７μｇ·ｍ－２·ｈ－１）,ＣＨ４通量为－８５．６３—－７．５８μｇ·ｍ－２·ｈ－１（平均－４１．４５μｇ·ｍ－３·ｈ－１）,并观察到在Ｎ２Ｏ排放和ＣＨ４吸收之间有着相互消长关系．实验室培养实验表明,最大反硝化作用活性存在于土壤上层（０—６ｃｍ）;不同土壤的反硝化作用活性明显不同．山地暗棕色森林土的ＣＨ４吸收作用也主要发生在土壤的上层（０—１２ｃｍ）．     

东北羊草草原不同植被类型土壤微生物呼吸速率的初步研究

对不同植被类型土壤微生物呼吸速率的动态变化及其与生态因子相关性研究表明,微生物呼吸速率以羊草土壤最高（平均为１７．２μｌＣＯ２·ｇ－１干土·ｈ－１）,隐子草土壤最低（８．７９μｌＣＯ２·ｇ－１干土·ｈ－１）,并随着土壤深度而递减．高峰值在８月份（２８．３９μｌＣＯ２·ｇ－１干土·ｈ－１）．相关分析表明,微生物呼吸速率与微生物数量、植物生物量、土壤水热条件和营养成分的季节变化呈正相关,与土壤ｐＨ呈负相关．     

福建武夷山甜槠群落能量的研究

在生物量、生产力研究基础上,对武夷山甜槠（Ｃａｓｔａｎｏｐｓｉｓ ｅｙｒｅｉ（Ｃｈａｍ ｐ．ｅｘ Ｂｅｎｔｈ．） Ｔｕｔｃｈ．）群落各组分的热值、群落能量现存量、能量年净固定量以及太阳能转化效率进行了研究。结果表明：（１）甜槠群落各组分样品的干重热值具有一定的差异,树皮热值最高,细根热值最低。（２）甜槠群落的能量现存量达７８０５８４．１ ｋＪ·ｍ － ２,其中地上部分为６７８９１３．８ ｋＪ·ｍ － ２,占总量的８６．９８％ ;地下部分为１０１６７０．３ ｋＪ·ｍ － ２,占１３．０２％ 。（３）甜槠群落的能量年净固定量（１９９２年）为２６８５６．２ ｋＪ·ｍ － ２·ａ－ １,林地太阳光合有效辐射能的转化效率为１．２９６％ 。     

芋的组织培养

１植物名称芋（Ｃｏｌｏｃａｓｉａｅｓｃｕｌｅｎｔａ）品种江汉芋（多子芋类型）。２材料类别茎尖及微芽。３培养条件分化培养基：（１）ＭＳ＋６－ＢＡ３．０～５．０ｍｇ·Ｌ－１（单位下同）＋ＮＡＡ０．５;（２）ＭＳ＋６．ＢＡ１．０～２．０＋ＮＡＡ０．５。诱导生根培养基：（３）ＭＳ＋６－ＢＡ１．０～２．０＋ＮＡＡ０．１。培养基（１）、（２）中另加蔗糖３０ｇ·Ｌ－１,培养基（３）中加蔗糖１０ｇ·Ｌ１,琼脂６～７ｇ·Ｌ－１,ｐＨ５．８～６．０,１２１℃高温高压灭菌１５ｍｉｎ左右。光照度１５５～２０００ｌｘ,光…     

深圳福田白骨壤群落Cr,Ni,Mn的累积及分布

探讨了深圳福田自然保护区白骨壤红树林对Ｃｒ、Ｎｉ、Ｍｎ的吸收、累积及分布．结果表明,该林地土壤Ｃｒ、Ｎｉ、Ｍｎ含量从底层至表层逐步提高;表层（０～３０ｃｍ深）３种元素含量分别为７．９７、２５．０和５３７μｇ·ｇ－１,贮量分别为１０９９．８６、３４５０．００和７４１０６．００ｍｇ·ｍ－２．白骨壤植物各部位Ｃｒ、Ｎｉ、Ｍｎ含量范围分别为０．２８～０．７５、０．４３～７．６５和２５～１５５２μｇ·ｇ－１;植物对表层土壤加权平均富集系数为Ｍｎ＞Ｎｉ≈Ｃｒ．该群落Ｃｒ、Ｎｉ、Ｍｎ的现存累积量分别为６．０６、２０．７６和１６３１．１７ｍｇ·ｍ－２,年净存留累积量分别为０．４３、１．４３和１０７．９８ｍｇ·ｍ－２;林地残留物相应元素储量分别为Ｃｒ７８．００μｇ·ｍ－２、Ｎｉ１５３６．３３μｇ·ｍ－２和Ｍｎ４０５．５４ｍｇ·ｍ－２．该林区３种不同类型群落叶层Ｃｒ、Ｎｉ现存累积量为白骨壤林＞桐花树林＞秋茄林,Ｍｎ为秋茄林＞白骨壤林＞桐花树林．     

中国潜在植被生产力的分布与模拟

利用中国植被净第一性生产力ＮＰＰ（ｎｅｔｐｒｉｍａｒｙｐｒｏｄｕｃｔｉｖｉｔｙ）的散点测量数据及中国一般气象站气候记录资料,并根据附近气象站数据进行地理位置相关插值,采用Ｐｅｎｍａｎ方法计算潜在蒸散,用Ｔｈｏｒｎｔｈｗａｉｔｅ的土壤水分处理方法,计算了ＮＰＰ测定位点的水分平衡。结果表明ＮＰＰ与生长季实际蒸散、总蒸散、潜在蒸散显著相关,与干燥度成负相关。从生长季的实际蒸散、干燥度指标两参数出发,建立了ＷＢＩＮＰＰ模型：ＮＰＰ＝２．５５·ＧＡＥ·ｅ－４．２０９２２－１．９６６５ＡＩ。该模型考虑了植被生产力形成机制,与ＮＰＰ实测值相关性高达０．８４２,高于国际上著名ＮＰＰ模型Ｍｉａｍｉ模型、ＴｈｏｒｎｔｈｗａｉｔｅＭｅｍｏｒｉａｌ模型和Ｃｈｉｋｕｇｏ模型（相关系数为０．６５５～０．７３２）。最后利用ＥＩＳ软件对全国潜在ＮＰＰ分布格局进行了分析,从东南到西北逐渐减少,最大值出现在海南和台湾,大于２２ｔ·ｈｍ－２·ａ－１,长江中下游地区１２～１６ｔ·ｈｍ－２·ａ－１,华北平原为８～１２ｔ·ｈｍ－２·ａ－１,东北地区为４～８ｔ·ｈｍ－２·ａ－１;草原地区为２ｔ·ｈｍ－２·ａ－１左右,干旱荒漠小于２ｔ·ｈｍ－２·ａ－１。     

Recent advances in the study of Kaposi's sarcoma-associated herpesvirus replication and pathogenesis

It has now been over twenty years since a novel herpesviral genome was identified in Kaposi's sarcoma biopsies. Since then, the cumulative research effort by molecular biologists, virologists, clinicians, and epidemiologists alike has led to the extensive characterization of this tumor virus, Kaposi's sarcoma-associated herpesvirus(KSHV; also known as human herpesvirus 8(HHV-8)), and its associated diseases. Here we review the current knowledge of KSHV biology and pathogenesis, with a particular emphasis on new and exciting advances in the field of epigenetics. We also discuss the development and practicality of various cell culture and animal model systems to study KSHV replication and pathogenesis.     

The structure, reproduction and taxonomy of Vidalia and Osmundaria (Rhodophyta, Rhodomelaceae)

Comprises species occurring mostly in subtidal habitats in tropical, subtropical and warm-temperate areas of the world. An analysis of the type species, V. spiralis (Sonder) Lamouroux ex J. Agardh, a species from Australia, establishes basic characters for distinguishing species in the genus. These characters are (1) branching patterns of thalli, (2) flat blades that may be spiralled on their axis, (3) width of the blade, (4) primary or secondary derivation of sterile and fertile branchlets and (5) position of sterile and fertile branchlets on the thalli. Application of the latter two characters provides an important basic method for separation of species into three major groups. Osmundaria , a genus known only in southern Australia, was studied in relation to Vidalia , and its separation from the Vidalia assemblage is not accepted. Species of Vidalia therefore are transferred to the older genus name, Osmundaria. Two new species, Osmundaria papenfussii and Osmundaria oliveae are described from Natal. Confusion in the usage of the epithet, Vidalia fimbriala Brown ex Turner has been clarified, and Vidalia gregaria Falkenberg, described as an epiphyte on Osmundaria pro/ifera Lamouroux, is revealed to be young branches of the host, Osmundaria prolifera.     

New or rare chromosome counts in Artemisia L. (Asteraceae, Anthemideae) and related genera from Kazakhstan

Fifteen chromosome counts of six Artemisia taxa and one species of each of the genera Brachanthemum, Hippolytia, Kaschgaria, Lepidolopsis and Turaniphytum are reported from Kazakhstan. Three of them are new reports, two are not consistent with previous counts and the remainder are confirmations of very scarce (one to four) earlier records. All the populations studied have the same basic chromosome number, x = 9, with ploidy levels ranging from 2x to 6x. Some correlations between ploidy level, morphological characters and distribution are noted.     

肝癌中HBV和HCV基因和抗原的分布及意义

采用原位分子杂交方法检测HCV RNA及HBV X基因;采用免疫组织化学方法研究HCV核心抗原,非结构区C33c抗原及HBxAg在肝细胞肝癌中的定位及分布.结果表明(1)HCV RNA、HBV X基因在肝细胞肝癌组织检出率分别为40%(55/136)和82%(112/136).HCV RNA定位于癌细胞的胞浆内,阳性细胞呈散在、灶状及弥漫分布三种形式;HBV X基因在肝癌细胞中的分布呈胞浆型、核型及核浆型,阳性细胞也呈上述三种分布形式;(2)HCV C33c抗原、核心抗原在肝细胞肝癌中的阳性率为81%(133/164)及86%(141/164).C33c抗原定位于癌细胞及肝细胞的胞浆内;核心抗原既定位于癌细胞核中,又可定位于胞浆中.C33c抗原阳性细胞以灶状分布为主;而核心抗原阳性细     

Selection with two alleles and complete dominance

For a plant selection model with frequency-independent viabilities, fertilities and selfing rates, it is shown that apart from global fixation, for certain parameter combinations a protected polymorphism and facultative fixation (either allele may become fixed according to initial frequencies) may both occur. Facultative fixation requires different selling rates for the dominant and recessive type. Protection of the polymorphism requires resource allocation for male and female function. In this connection the problem of purely genetically caused population extinction is discussed.
For general frequency dependence and regular segregation, the chances for establishment of a completely recessive gene are compared to those of a completely dominant gene. It is proven that the process of establishment of the recessive gene, despite a fitness advantage, may be considerably endangered by drift effects if random mating prevails. The recessive gene may reach the same effectivity in establishment as a dominant gene, only if the recessive homozygote mates exclusively with its own type during the period of establishment.