Discovery of the eclogite and its petrography in the Northern Dabie Mountain

Eclogite from the Northern Dabie Mountain is a new finding by the authors. These eclogites in foliated perdotite are enveloped by banded gneiss and occur in the mafic-ultramafic rock belt. They are mainly composed of omphacite, garnet, diopside, orthopyroxene, amphibole, plagioclase and magnetite, and a small amount of rutile, spinel, olivin and 鏾rundum. The mineral association of peak metamorphism of the eclogite is omphacite+garnet+rutile. The existence of eclogite in the Northern Dabie Mountain implies that there was an eclogitic metamorphism prior to the granulitic facies one in the mafic-ultramafic rock belt.     

Response of mollusk assemblages from the Luochuan loess section to orbital forcing since the last 250 ka

This note presents a new result of terrestrial mollusk study from the Luochuan loess section since the last 250 ka. A total of 213 samples, taken at intervals of 10 cm in the S₀-L₃ portion, were analyzed for fossil mollusks. Generally, 150–600 individuals were counted in each sample. According to the distribution of mollusk fossil assemblages in the loess section, 11 mollusk fossil zones have been recognized, representing different climatic and ecological conditions. Three main ecological groups were identified according to the temperature and moisture requirements of each taxon. The cold-aridiphilous group shows maxima at about 240–220, 190–182, 150–140 and 74–66 ka BP. The thermo-humidiphilous set has high abundances for at least 6 times in the section at about 246–240, 220–216, 170–158, 92–86, 60–44 and 10 kaBP. Our results show that variations in mollusk ecological groups are related with changes in the Earth orbital parameters at the 41 and 20 ka frequencies. Maxima in thermo-humidiphilous taxa are in phase with accretion intervals of obliquity (41 ka period), reflecting the East Asian summer monsoon with 41 ka period in controlling variations in terrestrial mollusk ecological groups. In addition, maxima in thermohumidiphilous taxa appearing at about 246–240, 220–216, 60 and 10 kaBP, are consistent with procession (20 ka period) maxima, indicating that the procession period also plays an important role in adjusting the ecological pattern of mollusk groups.     

大肠杆菌甜菜碱醛脱氢酶基因的测序及对烟草的转化

对利用聚合酶链式反应所克隆的大肠杆菌ｂｅｔＢ基因进行了序列测定,结果证实获得了该基因的克隆ｐＸＹ０１,ｐＸＹ０５以及亚克隆ｐＸＹ１１。将该基因置于ＣａＭＶ３５Ｓ启动子调控下,导入根癌农杆菌ＬＢＡ４４０４中,叶盘法转化烟草,在含卡那霉素的选择培养基上筛选抗性芽,并进一步诱导小植株的再生。利用ＰＣＲ技术检测基因整合到烟草基因组中。     

The electron-beam (EB) irradiation and grafting of acrylic monomers onto EPDM copolymer

Radiation techniques (electron-beam, γ-ray, etc.) are usually used for improving the compatibility between polymer and ingredients in composite materials. Electron-beam pre-irradiation has been used for the first time to enhance the flame retardance of EVA copolymer. Efforts are being made to decline the flammability for EPDM copolymer by EB technique and remarkable reduction has been attained through a series of treatments: pre-irradiation, grafting and saponification.     

L-谷氨酸盐酸盐晶体结构重新测定

鉴于Dawson和Sequeira分别报道的L-谷氨酸盐酸盐C5H10NO4Cl的晶体结构数据之间存在明显差别且键长精度也较低,重新测定了L-谷氨酸盐酸盐的晶体结构.结果表明:晶体为正交晶系,空间群为中心对称的P2(1)2(1)2(1),晶胞参数为a=5.129 8(14),b=11.715(3),c=13.259(4).在分子结构中,所有的键长和键角都在正常范围内,其中扭角ψ1和ψ2分别为-21.04(16)和161.61(11)°.原子Cγ偏转于N原子,同时原子Cδ与Cα处于反位.在晶体结构中,经过相关的平移和螺旋操作,分子通过N—H...O、N—H...Cl、O—H...Cl和O—H...O氢键的连接而形成了平行于bc平面的多聚体层.     

激光内调制自由空间光通信实验系统装置的研制

设计并安装调试了一套以激光内调制为工作模式的自由空间光通信实验系统装置,给出了原理框图及实际传输所得到的波形,分析了其频率极限.该装置已经用于相关专业课程的教学,效果良好,与其它光纤通信实验系统相比,该装置使用更加直观、方便.     

Carbonaceous particles in Muztagh Ata ice core,West Kunlun Mountains,China

Carbonaceous particles concentrations of OC and EC are determined using a two-step gas chroma- tography system in Muztagh Ata ice core covering the time period of 1955--2000. Over the period represented by the core, OC and EC concentrations appear to have changed significantly, varied in the range of 17.7--216.7 and 6.5--124.6, and averaged 61.8, 32.9 ng·g^-1, respectively. The average concentration of EC in Muztagh Ata ice core is much lower than that in an Alpine ice core record （100--300 ng·g^-1） during the same period, but it is a factor of 14 in Greenland ice core （2.3 ng·g^-1）, this may induce a strong impact on the snow albedo in the last 46 years in our study area. Observations indicate two periods with obviously high deposition concentrations （1955--1965 and 1974--1989） and two periods with low concentrations （1966--1973 and 1990--1995）, as well as a recent increasing trend. By comparing EC and SO4^2- concentration variations and deciphering OC/EC ratios recorded in the same ice core, we can judge roughly that the carbonaceous particles deposited in Muztagh Ata ice core were attributed to fossil fuel combustion sources.     

Impact of Internal Factors on Information Technology Adoption: An Empirical Investigation of Chinese Firms

Organizations differ significantly in their inclination to deploy information technology (IT). The factors that determine the organizational inclination to deploy IT need to be classified to help firms formulate an appropriate e-strategy. This paper discusses a framework that explains the influence of internal factors on IT adoption. The framework is based on quantitative data on IT adoption from 95 firms in China. The results highlight that the internal factors of leadership, organizational learning, and IT resources positively impact IT adoption. The study also shows that these factors are correlated.     

多Agent系统中的任务可调度问题

为了将Agent方法应用于应急系统等新领域,在对该类系统研究的基础上提炼出它们的公共特征,根据这些特征设计出一种MAS系统模型,并在该模型的基础上定义了相应的任务可调度问题.利用网络流模型对可调度问题进行了建模,证明了最大流算法可以求解该可调度问题,由此说明该问题是可多项式时间求解的.并且对于给定该问题的一个可调度实例,利用最大流算法还可在系统中找到一组Agent完成所有任务.通过对该网络流模型的进一步分析,得出并且证明了任务可调度判定的充分必要条件,利用这个结论可以快速判断当前任务是否可调度.