Different fossil brachiopod skeletal microstructure of different information on carbon and oxygen isotope contents

Whether there is isotope fractionation caused by metabolism (vital effect) of bra-chiopods in geologic time with their shells' δ18O and δ13C has been studied intensively in the field of carbonate isotope geochemistry in the last decade. The approach to dealing with the problem is by comparing isotopic compositions between different fossil brachiopods with their secondary shells which usually consist of two kinds of layers: prismatic layer composed of prismatic low-Mg calcite crystals, and fibrous layer comprising fibrous ones. The isotopic compositions of the two secondary layers have been investigated by comparison of carbon and oxygen isotopic compositions between five genera of Atrypidae collected from Givetian, Middle Devonian in Longmenshan, Sichuan Province, China. Due to different microstructures of the two secondary layers, their abilities to prevent from being altered by diagenesis are also different, thus in their state of preservation. The fibrous layer is more susceptible to the diagenetic alternation than the prismatic one in the way of microfracture filling between fibrous crystals in the elongated direction. Consequently, the isotopic compositions of the fibrous layer are systematically lower than those of the prismatic layer in their δ18O and δ13C by (0.53 ± 0.08)‰ and (0. 12 ± 0.04)‰, respectively. This suggests that further studies of vital effects with brachiopod in geological times by comparison of isotopic compositions in the secondary shell take into consideration of the different states of preservation between the fibrous and the prismatic layer.     

-150℃逆布雷顿空气制冷机动态温降特性研究

为了研究空气制冷机的动态温降特性,对采用工作轮直径为24 mm的小型透平膨胀机和板翅式换热器的逆布雷顿循环空气制冷机实验台进行了改进.采用高真空绝热冷箱对制冷机进行绝热,可使绝对压力低于10-3 Pa,得到的设计制冷温度为-150℃.对不同进口参数和采用不同直径风机轮的制冷机工况进行了实验研究,获得了透平膨胀机的实际温降曲线；以实验系统为基础建立了数学模型,得到了相应的理论温降曲线.研究结果表明:风机轮尺寸对空气制冷机动态温降过程的影响较大,实验的最低温度低于-150℃；所建理论模型能够较好地预测实际系统温降的过程.     

清代词社的时代特征

词社萌芽于北宋，成型于南宋末期，到了清代随着词学复兴而高度繁荣，表现出不同于前代的时代特征：形成了全国性的词社网络，促进了各地词学的交流和互通；词学结社目的高度觉醒，词社更具专业性，对词学的发展有着积极的促进作用；社集内容多样，为词学文献的丰富做出了贡献。     

Genome-wide association study identifies eight new risk loci for polycystic ovary syndrome

Following a previous genome-wide association study (GWAS 1) including 744 cases and 895 controls, we analyzed genome-wide association data from a new cohort of Han Chinese (GWAS 2) with 1,510 polycystic ovary syndrome (PCOS) cases and 2,016 controls. We followed up significantly associated signals identified in the combined results of GWAS 1 and 2 in a total of 8,226 cases and 7,578 controls. In addition to confirming the three loci we previously reported, we identify eight new PCOS association signals at P < 5 × 10(-8): 9q22.32, 11q22.1, 12q13.2, 12q14.3, 16q12.1, 19p13.3, 20q13.2 and a second independent signal at 2p16.3 (the FSHR gene). These PCOS association signals show evidence of enrichment for candidate genes related to insulin signaling, sexual hormone function and type 2 diabetes (T2D). Other candidate genes were related to calcium signaling and endocytosis. Our findings provide new insight and direction for discovering the biological mechanisms of PCOS.     

基于邻近目标置信度评估的视觉目标跟踪与定位

针对视觉目标跟踪与定位中,目标因为无特征或被严重遮挡导致无法定位的问题,设计了一种基于邻近目标置信度评估的视觉目标跟踪与定位算法。在跟踪过程中,通过检测提取邻近目标的标记特征,然后结合每个特征标记的汉明距离和相对其他标记的归一化结果以及每个标记发生的概率,得到每个标记最终置信度,选择置信度最大的邻近标记来确定目标位置。实验结果表明,该算法在对目标存在遮挡或目标没有特征的情况可以大大提高跟踪的鲁棒性和准确性。     

行动能力的作用——对·华女阿五·中黄玉雪成功融合双重身份的分析

Agency is one important aspect of subjectivity in literary studies. This paper has adopted the sense of agency to analyze how Jade Snow Wong successfully integrates her two identities in Fifth Chinese Daughter which is considered as the pioneering Chinese-American literary work.     

小分子给受体化合物的合成及光伏性质研究

合成了新型的给受体化合物PLY-S2O。用溶液旋转涂膜的方法,分别将PLY-S2O作为电子给体和电子受体制备了本体异质结光伏器件,器件结构为ITO/PEDOT:PSS/active layer/LiF/Al。在AM 1.5G模拟太阳光100 mW/cm~2的照射光强下,以PLY-S2O为电子给体时,能量转化效率为0.035%;当以PLY-S2O为电子受体时,相应的能量转化效率达到0.064%。     

有源配电网两阶段动态应急抗灾运行策略

由于台风等动态灾害具有持续性和渐变性的特点,增加了故障恢复过程的复杂性。为使有源配电网快速恢复供电,建立包含资源分配预案、孤岛划分方案和抢修与复电协同方案的两阶段动态应急抗灾运行策略和相应的整体优化模型。第一阶段根据路程时间和预计受灾地区与抢修资源的属性匹配情况制定灾前资源分配预案;第二阶段根据已受灾地区的灾情信息制定孤岛划分方案和抢修与复电协同方案,并根据灾情的动态变化做相应的方案调整。通过IEEE33节点系统进行算例仿真,验证了策略的有效性。     

基于最小拍无纹波数字化的PMSM速度调节器

研究用最小拍无纹波数字化方法设计永磁同步电动机（PMSM）伺服系统速度调节器.把电机传动过程模型的连续域传递函数转换成数字域z形式传递函数,根据速度指令的z变换输入形式,设定预期误差传递函数,使得在有限拍内能输出稳定的速度信号,然后依据最小拍无纹波零极点配置原则,反推出数字调节器的形式,并使速度调节器输出的电流指令信号...     

一类非线性边值问题正解的存在唯一性

利用锥映射方法,根据压缩映像原理,讨论了一类非线性微分方程的边值问题,得到了该微分方程边值问题正解存在的有关结论.