Petrology and mineral chemistry of new ureilites found in Grove Mountains, Antarctica

Petrography and mineral chemistry of two new ureilites, GRV 021512 and 022931, from the Grove Mountains, Antarctica, are reported in this paper. GRV 021512 exhibits a typical ureilite texture, and consists of 48.3% olivine, 9.4% pigeonite and 38.1% carbonaceous interstitial material and/or reduction product. GRV 022931 has a cataclastic porphyritic texture, and consists of 19.1% olivine and 14.1% pigeonite embedded in 66.3% carbonaceous interstitial material and/or reduction product. The coarse-grained olivine and pigeonite in both meteorites have homogeneous cores, and they are FeO-rich within the range of the ferroan subgroup （subgroup I） of olivine-pigeonite ureilites. All olivine grains of the meteorites show reduction zones along boundaries and cracks. Abundant diamond coexists with graphite as graphite-rich patches and veins in the carbonaceous interstitial material. Petrogenesis of both meteorites and the origin of diamond are discussed.     

构造二项式系数恒等式

讨论了牛顿二项式定理,获得了新恒等式,给出了其应用实例.     

Anti-Interference Low-Power Double-Edge Triggered Flip-Flop Based on C-Elements

When the input signal has been interfered and glitches occur,the power consumption of Double-Edge Triggered Flip-Flops (DETFFs) will significantly increase.To e...     

视频序列中运动人脸的检测与特征定位

针对视频序列中运动人脸的检测与特征定位问题,给出了一种算法,即通过计算并比较人脸区域而不是整幅视频帧的峰值信噪比（PSNR）,先从视频序列中找到人脸区域清晰度高且尽可能大的视频帧,然后再进行人脸的准确检测与特征定位。首先利用Adaboost方法检测出人脸的大致范围,再根据肤色模型确定人脸的具体位置并从图像中提取出人脸部分,然后利用基于帧间差的人脸区域的PSNR判断图像清晰度,从而定位出人脸区域清晰度高且尽可能大的视频帧,最后进行人脸检测和特征定位。对实际视频序列的计算表明,给出的算法在时间效率上较高,人脸的检测与特征定位效果较好。     

湖北省高等教育投入-产出状况的偏最小二乘回归分析

教育发展是国家基本建设的重中之重,而对教育进行投资是有效促进教育事业发展和经济建设的重要途径之一.首先对衡量高等教育产出的因子进行多重相关性检验,然后利用偏最小二乘回归的方法对湖北省高等院校的教育投入与产出情况进行了一个初步的分析,建立高等教育投入与产出的一个结构模型,以期对我国的高等教育发展提供一个可供借鉴的参考.     

一类亚纯函数的主部分解方法

探讨了复分析中关于亚纯函数的主部分解问题,并利用留数得到了一类仅具有一阶极点的亚纯函数主部分解的具体方法.     

Capacity analysis of high-rank line-of-sight MIMO channels

Matrix perturbation theory is utilized to investigate high-rank line of sight multiple input multiple output channels in a microwave relay system. The upper and lower bounds of channel capacity are derived based on space time block codes technique and singular values decomposition. A useful constraint for designing LOS MIMO channels is developed by the use of the condition number of the MIMO channel matrix. The theoretical analysis of channel capacity is confirmed by the simulation. The results show that the proposed method is able to give a physical explanation of the high-rank LOS MIMO channel matrix characteristics.     

Stretching and imaging studies of single DNA molecules

DNA molecules were stretched on silanized mica surface with the molecular combing technique, and detected with fluorescence microscopy and atomic force microscopy. Meantime, DNA molecules were stretched with a modified dynamic molecular combing technique and studied with atomic force microscopy. The results indicate that, compared with the dynamic molecular combing technique, the modified dynamic molecular combing technique has advantages of less-sample demand and less contamination to sample; as compared with the molecular combing technique, it has better aligning effect and reproducibility. Combination of this kind of DNA molecular manipulating technique with the single DNA molecule detecting technique by atomic force microscopy and fluorescence microscopy will play an important role in the basic research of molecular dynamics and the application of gene research.     

英语科技文献中的汉译探讨

本文笔者对科技英语汉译时的词义选择、词的增减、词的重译、转换和句子分析等诸方面进行了探讨。     

离子交换法提取D-对羟基苯甘氨酸

研究了离子交换树脂提取D-对羟基苯甘氨酸的方法,包括树脂的筛选,吸附条件和洗脱条件的确定.