Mitochondrial DNA variation analysis suggests extreme low genetic diversity in Guizhou snub-nosed monkeys （Rhinopithecus brelichi）

Guizhou snub-nosed monkey (Rhinopithecus brelichi) is a unique, endangered primate in China, mainly distributed in Fanjing Mountain National Natural Reserve, Guizhou Province, in an area of 275 km2. Recently, habitat loss and fragmentation have caused population isolation. To assess genetic diversity within this species and its population structure, we sequenced 400 bp of the hypervariable I segment from the mitochondrial DNA control region for 128 individuals. Only one haplotype was identified from these individuals. Compared with other primate species, R. brelichi can be regarded as a species with very low genetic diversity, which further adds to the conservation concern.     

Multi-threshold second-order phase transition in laser

We present a theory of the multi-threshold second-order phase transition,and experimentally demonstrate the multi-threshold secondorder phase transition phenomenon.With carefully selected parameters,in an external cavity diode laser system,we observe secondorder phase transition with multiple(three or four) thresholds in the measured power-current-temperature three dimensional phase diagram.Such controlled death and revival of second-order phase transition sheds new insight into the nature of ubiquitous secondorder phase transition.Our theory and experiment show that the single threshold second-order phase transition is only a special case of the more general multi-threshold second-order phase transition,which is an even richer phenomenon.     

Rapid growth and sterility of growth hormone gene transgenic triploid carp

Triploid carp (100%) with 150 (3n=150) chromosomes were obtained by crossing the females of improved tetraploid hybrids (♀, 4n=200) of red crucian carp (♀)×common carp (♂) with the males of diploid yellow river carp (♂, 2n=100). The crosses yielded transgenic triploid carp (positive triploid fish, 44.2% of the progeny) and non-transgenic triploid carp (negative triploid fish). Histological examination of the gonads of 24-month-old positive triploid fish suggested they were sterile and the fish were not able to produce mature gametes during the breeding season. Morphologically, both the positive and negative triploid fish were similar. They had a spindle-shaped, laterally compressed, steel grey body with two pairs of barbells. Most of the quantifiable traits of the triploid carp were intermediate between those of the two parents. The positive and negative triploid fish were raised in the same pond for 2 years. The mean body weight of the positive triploid fish was 2.3 times higher than the negative triploid fish. The weight of the largest positive triploid fish was 2.91 times higher than that of the largest negative triploid fish. Thus, we produced fast-growing transgenic triploid carp that have a reduced ecological risk because of their inability to mate and produce progeny.     

考虑参数和模型不确定性的基桩承载力可靠度

对参数和模型的不确定性因素进行了分析,若不能正确地考虑参数和模型不确定性对基桩承载力的影响,则桩的安全性会被低估.为此,引入修正因子对承载力的试计比和变异系数进行修正,消除了参数和模型不确定性对可靠度分析产生的影响,并给出了修正后可靠度指标的计算方法.算例分析表明：修正后的可靠度指标大于原始可靠度指标,桩的安全性被正确...     

向家坝水电站人工砂石系统生产工艺选择及后期调整

介绍了向家坝水电站马延坡砂石加工系统的工艺流程情况及后期工艺调整的原因、调整所采取的措施及其效果,为今后人砂系统的工艺设计及工艺转化提供了一些可借鉴的经验和思路.     

新型网壳节点的弹塑性分析及试验研究

简要介绍了一种广泛应用于各类意志支,双层网壳结构的新型承插式节点,在弹塑性理论分析的基础上,进行了一组单向拉,压试验研究,为今后在实际工程中推广这种新型节点提供了可靠依据。     

新型钢管砼框架节点试验研究及其应用

给出了钢管混凝土框架节点的试验结果,并采用有限元法对新型节点模式进行了应力场分析。介绍了该新型节点的设计方案及在实际工程中的应用。     

AHP法在空调冷热源方案选择中的应用

从空调冷热源设计的实际需要出发,提出了将系统工程中著名的ＡＨＰ法引入设计方案决策的新途径．在简要论述ＡＨＰ法基本思想和步骤的基础上,着重分析了ＡＨＰ法在实用中存在的问题,探讨了一种直观、高效的构造具有足够满意一致性ＡＨＰ判断矩阵的新方法,并运用该法对某大厦空调冷热源设计的具体实例进行了计算,得出了合理的结论．结果表明,ＡＨＰ法能够成功地应用于空调冷热源方案选择的决策．     

一类半线性椭圆型方程多解的存在性

本文讨论一类带有次线性项和超践线性项的半线性椭圆方程Domehlet边值问题多正解的存在性及解的某些性质。     

DMloDS的多媒体存储服务器中可丢弃帧的分配问题

分布式多媒体信息点播系统（ＤＭＩｏＤＳ）要求其多媒体存储服务器能够同时为大量的客户提供实时的信息服务,为了保证每个客户的ＱｏＳ要求,系统必须提供接纳控制机制以限制客户的数量．首先从理论上描述了一种适合于ＤＭＩｏＤＳ中多媒体存储服务器的统计型接纳控制算法ＳＡＣＡ,并对统计过程中产生的可弃帧的分配问题进行了深入的研究,提出了可丢弃帧分配的数学模型,保证了每个客户的基本ＱｏＳ要求,为ＤＭＩｏＤＳ系统的设计提供了理论依据