Reproductive ecology of the glass frog Espadarana prosoblepon (Anura: Centrolenidae) in an urban forest of the Central Andes of Colombia

Population and reproductive behaviour aspects of the glass frog Espadarana prosoblepon are well known for populations from Central America, but similar information is lacking for populations from South America. We recorded the reproductive ecology of a population of the glass frog E. prosoblepon in the city of Armenia, Central Andes of Colombia. With weekly surveys with mark-recapture between December 2013 and November 2015, we monitored activity patterns and evaluated if the probability of males mating is associated to their body size or to chorus tenure (i.e. the number of nights a same individual is calling for attracting a mate). In addition, upon observing an amplexus, we recorded the behaviour of the individuals until oviposition and noted characteristics of egg clutch. We recorded 47 males and 32 females, nine amplexus events, eight ovipositions, and 21 egg clutches (35.4 ± 4.79 eggs per clutch, N = 29). Activity of males and females and the number of egg clutches were positively correlated to rainfall. Mating success of males was not associated to their body size, but it was positively associated to longer chorus tenure; clutches from large females had a higher number of eggs than clutches from small females. Oviposition occurred on average 3.76 ± 1.74 hours after we first observed the amplexus, occurring 93.1% of the time in fronds of Selaginella geniculata at an average height of 1.58 ± 0.44 m. After the oviposition, the male left the site, while the female remained between 30 and 45 min, partially covering the eggs. The reproductive behaviour of E. prosoblepon did not vary widely between a population in Costa Rica and our population in time to oviposition, and mating success of males associated to chorus tenure; however, in our study population we recorded a larger clutch size and the preference for S. geniculata fronds as oviposition substrate.     

铝胺钻井液在青东古1井的应用

通过优选抑制剂和封堵剂，确定了铝胺钻井液体系配方，配合相应的现场维护处理工艺，解决了沙河街组地质构造复杂，断层、地应力及层理性泥岩易导致井壁失稳等问题，保证了沙河街组的井壁稳定，使该井提前完钻，提高了钻井时效．该井的钻探成功为深化研究青东区块成藏条件提供了基础资料，有助于该区块进一步的勘探开发．     

一种由三角模所诱导的粗糙集间的相似性度量方法

给出两粗糙集间一种新的相似度计算方法,并将其应用到模糊模式识别问题中,通过算例说明这种方法的可行性和有效性.     

Ants feeding on anal exudate from tortricid larvae: a new type of trophobiosis

A new type of trophobiosis between tortricid larvae of a hitherto unknown genus and species, and various ant species of the subfamilies Formicinae, Dolichoderinae and Myrmicinae, was found in Malaysia. The larvae live in silken shelters fixed to the leaves of bamboo. In response to mechanical stimuli from the ants, they discharge from the anus a liquid containing sugar and amino acids and/or protein. The tortricid is described as Semutophila saccharopa gen. nov., sp. nov.; a second species, S. susurra sp. nov., is described from New Guinea.     

基于时间序列分析的独居老人活动量研究

为解决独居老人日常生活的监护问题, 提出一种基于时间序列分析与模糊模式识别的独居老人活动量研究方法。该方法将独居老人的日常活动量作为对独居老人生活状况监测的有效指标, 并利用时间序列分析对活动量时间序列建立预测模型, 利用模糊模式识别法鉴别活动量监测值与活动量预测值之间的差距, 当两者之间的差距超过正常范围时, 将预警信息反映给老人的监护人, 以便监护人对老人的生活状态是否异常予以关注。实验结果表明, 该方法对老人异常状态的识别准确率为96. 97%。从而为老人生活状况的研究提供了一种新的方法和途径。     

模糊模式识别中隶属函数选取的探讨

通过数值实例,论证了利用最大隶属度原则对三角形类型模糊模式识别时隶属函数选取的优越性,并提出了一种给定阈值且以三角形内角和差关系作为底数变量和指数变量的指数型隶属函数.     

1986-2007年中国耕地面积时空变化分析

根据统计数据,运用逐步回归方法分析了我国1986-2007年耕地面积的时空变化规律及影响因素.结果表明:中国耕地面积和人均耕地面积一直在减少,1999年以后减速加快.以1996年为界线,中国耕地面积从1980-1990年东部部分省份锐减、中西部大部分省份增加的格局转变为1996-2007年的西部锐减、中部次之,东部减速缓慢的格局.1986-1996年耕地面积减少的主要因素是城市人口和人口自然增长率,1996-2007年主要因素是第二产业产值、全国总户数,1986-2007年主要是城市人口、第二产业总产值、乡镇企业增加值及耕地总量平衡政策的发展.     

简析中西思维方式的差异

思维方式的差异是中西方之间最根本的差异之一。文中就中西方在思维方式上的差异,怎样正确认识中西交流中思维方式的差异进行了阐述,为中西方文化冲突的解决提供参考。     

Specialist and generalist species in habitat use: implications for conservation assessment in snakes

Habitat specialization is recorded as one of the central factors that make species vulnerable to extinction. Among snakes, there is considerable variation in this trait, as some species are specialists and others are generalists in habitat use. We have quantified habitat specialization in the snakes of the southern Iberian Peninsula, and compared it with their abundance and IUCN categories. All data were combined for a principal components analysis that discriminated two main groups: three generalist species that live in all types of habitat, and five specialist species that ranged from rather scarce to extremely rare and are found only in unaltered habitats. The three generalist snakes are not threatened and their IUCN category is Least Concern. Three out of the five specialist species are categorized as Near Threatened, Vulnerable, and Endangered at regional or national levels. The other two species are currently considered Not Threatened and we discuss whether they are incorrectly classified. The conservation status of snakes is difficult to evaluate because of their secretive habits and low population densities. We suggest that quantifying habitat specialization may be a useful tool for assessing the conservation status of secretive organisms such as snakes.     

论抗日根据地科技社团的发展及其作用

在中共的领导和支持下,陕甘宁、晋察冀等根据地兴起了影响深远的自然科学运动。创立各类科技社团则成为这场运动的有机组成部分。抗日根据地的科技社团在汇聚人才、培养科技干部,服务边区经济建设、推进科学知识的传播以及在参政议政、决策咨询和对外联络等方面均做出了不可磨灭的贡献。这对于今天监督和指导科技社团的健康发展仍具有一定的参考和借鉴意义。