国外洞穴研究概况

<正> 洞穴是可溶岩石中最常见的一种岩溶现象,它是最广泛,最深入研究的岩溶形态之一。其研究范畴几乎包括了岩溶学的全部领域,它的独特特征和重要的学术及实际意义使它在岩溶学中具有特殊的地位。洞穴研究已逐步发展为一门独立的学科——洞穴学,且派生出一些分枝,如生物洞穴学等。      

甘肃省河西走廊干旱地区沙漠化灾害灾情分析及其减灾对策

甘肃省河西走廊是干旱沙漠化灾害有代表性的地区之一。土地沙化、旱化、次生盐渍化、风灾和干热风灾害的年直接经济损失达1-2亿元。据研究, 由于不乐观的自然因素及人口压力过大, 灾害有加剧趋势。但临泽试验站减灾试验表明: 灾害不仅可以防治, 而且有较大经济效益。为此, 建议:(1)大力开展全民减灾教育, 建立群防体系;(2)开展灾害评估研究, 建立减灾综合试验示范区;(3)建立灾害监测系统, 搞好预报;(4)预防沙漠化发生发展, 研究实用技术和提供必要的防治和研究经费。     

洞穴黑暗带中有无叠层石?

本文从叠层石概念入手,通过介绍前人大量关于蓝藻(蓝细菌)和细菌在弱光和黑暗环境中的习性,及其在叠层石形成中的作用,讨论了叠层石形成的两大影响要素: 生物控制和环境影响。并提出了以模拟试验的有效方法论证叠层石在洞穴黑暗带中形成的可能性。      

基于网络药理学和分子对接探讨石韦大枣汤干预白细胞减少症的作用机制

目的：基于网络药理学和分子对接技术探究石韦大枣汤治疗白细胞减少症的作用机制。方法：通过TCMSP数据库筛选石韦大枣汤治疗白细胞减少症的活性成分和潜在靶点,构建石韦大枣汤与白细胞减少症蛋白质-蛋白质相互作用网络（PPI）,分析基因本体（GO）功能和京都基因与基因组百科全书（KEGG）通路,采用分子对接技术对主要活性成分与核心靶点进行分子对接。结果：石韦大枣汤中有效成分28种,93个靶点作用于白细胞减少症,关键靶点有靶向细胞周期蛋白D1（CCND1）、可调控信号传导和转录激活子3（STAT3）、半胱氨酸天冬氨酸特异性蛋白酶3（CASP3）、缺氧诱导因子1A（HIF1A）等,涉及KEGG富集分析确定信号通路包括脂酰肌醇3激酶-蛋白激酶B（PI3K Akt）信号通路、晚期搪基化终产物及其受体（AGE RAGE）信号通路、Janus激酶-信号转导与转录激活因子（JAK STAT） 信号通路等多条通路。分子对接结果显示,槲皮素与血管内皮生长因子A（VEGFA）大分子蛋白,β-谷甾醇与CASP3有良好的结合性。结论：石韦大枣汤治疗白细胞减少症具有多靶点、多通路的特点,为深入研究其作用机制提供了新依据。     

台湾-阿尔泰地学断面阿尔金-龙门山剖面的地壳纵波速度结构

通过分析阿尔金—龙门山地学断面的地震资料,建立了该剖面的地壳纵波速度结构。研究结果表明,阿尔金北侧的塔里木盆地地区莫霍面为50km,而在其南侧的祁连地块莫霍面突然加深至73km,在柴达木盆地莫霍面又抬升至58km左右,然后,在松潘甘孜地块莫霍面降至70km,并呈现为台阶状向龙门山方向抬升到60km左右,最低速层,而在其南部地区则没有低速层出现,推测低速层为地壳中部的局部熔融物质,阿尔金—龙门山剖面上的两个莫霍面坳陷区分别与祁连地块和松潘—甘孜地块上的两个莫霍面坳陷区相对应,指示出这个两个地块具有较深的山根,青藏高原北部的巨厚地壳很可能是由于中生代以来发生的印度板块与亚洲板块碰撞时受到来自东西及南北方向的挤压,使地壳缩短所致。     

First record of Pantropical spotted dolphins Stenella attenuata in the Yellow Sea,China

On October 1, 2009, sixteen dolphins were obtained from fishermen by incidental catching in the Yellow Sea, China. As the dolphins' skin color was ambiguous, morphological parameters were measured, and mitochondrial DNA cytochrome b(Cyt b) gene sequence was studied to identify the species. Morphological characteristics were consistent with Pantropical spotted dolphins, S tenella attenuata. Furthermore, a partial mitochondrial DNA cytochrome b(Cyt b) gene sequence as long as 328-bp was studied by extracting genomic DNA from the skins, and six haplotypes were detected in the sixteen dolphins. By comparing homologous sequences available in Gen Bank(www.ncbi.nlm.nih.gov), all the six haplotypes had maximal genetic similarity with Pantropical spotted dolphin. Eight species of cetacean(whales and dolphins) are now recognised in the Yellow Sea. To the best of our knowledge, this is the first record of Pantropical spotted dolphins from this region. Despite this species being listed as a Grade II National Key Protected Animal since 1988, little is known of its biology in Chinese waters. We recommend remedial research be undertaken to ensure appropriate management.     

The Relative Impact of Regional Scale Land Cover Change and Increasing CO_2 over China

A series of 17-yr equilibrium simulations using the NCAR CCM3 (T42 resolution) were performed to investigate the regional scale impacts of land cover change and increasing CO2 over China. Simulations with natural and current land cover at CO2 levels of 280, 355, 430, and 505 ppmv were conducted. Results show statistically significant changes in major climate fields (e.g. temperature and surface wind speed) on a 15-yr average following     

Precambrian acritarcha: A cautionary note

Extensive studies have shown that acritarch-like artifacts, ‘pseudomicrofossils’, may be easily produced during acid maceration of samples. Such acritarch-like forms may also be found in rocks and in modern ecological settings. The most common pseudomicrofossils are microstructures which have specific gravities less than unity. Such ‘light-microfossils’ have been described previously by A.C. Lopuchin and coworkers (1978). Experiments have more recently been conducted, including microscopic observations and scanning electron microscopy, the results revealing that these ‘light-microfossils’ actually consist of finely-dispersed organic substances and that pseudomicrofossils can be formed during each step of the customary maceration processes. Consequently, care must be taken when referring to certain published taxa, particularly to forms resembling Trachysphaeridium, Asperatopsophosphaera, Pseudozonosphaera, Trematosphaeridium, Taeniatum and the Polyporata morphotypes, because they may include artifacts. The purpose of this preliminary report is to point out that, while there are many real acritarchs described and carefully diagnosed in the literature, a number of reports of artifacts merely resembling acritarchs have also been published inadvertently. In a broader sense, during the past 50 years numerous morphotypes assumed to be the remnants of organisms have been described from Precambrian strata. Many of the Precambrian microstructures are, in fact, not microfossils at all but various microstructures unrelated to syngenetic microorganisms.     

2004年临汾市高温的气候特点和环流特征分析

本文从分析亚欧环流形势出发,对比历史资料平均情况,对造成2004年临汾市持续高温的500hPa高度场和850hPa的温度场的实况资料以及平流等物理量作了较详细的分析,找出了临汾市夏季出现高温的可能指标。     

The Altun Fault: Its Geometry, Nature and Mode of Growth

The Altun (or Altyn Tagh) fault displays a geometry of overlapping of linear and arcuate segments and shows strong inhomogeneity in time and space. It is a gigantic fault system with complex mechanical behaviours including thrusting, sinistral strike slip and normal slip. The strike slip and normal slip mainly occurred in the Cretaceous-Cenozoic and Plio-Quaternary respectively, whereas the thrusting was a deformation event that has played a dominant role since the late Palaeozoic (for a duration of about 305 Ma). The formation of the Altun fault was related to strong inhomogeneous deformation of the massifs on its two sides (in the hinterland of the Altun Mountains contractional deformation predominated and in the Qilian massif thrust propagation was dominant). The fault experienced a dynamic process of successive break-up and connection of its segments and gradual propagation, which was synchronous with the development of an overstep thrust sequence in the Qilian massif and the uplift of the Qinghai-T