共查询到20条相似文献,搜索用时 187 毫秒
1.
王进军 《吉林化工学院学报》1997,14(1):33-36
利用deMayo光环加成反应构成了螺环倍半萜岩兰烷属系列天然产物的基本构架,再经多步化学修饰,完成了(±)-β-岩兰酮,(±)-鲸螺醇和(±)-异鲸螺醇的全合成. 相似文献
2.
在水溶液中,Pd^2+与SCN^-,4,4’-联吡啶通过分子自组装形成台阶式一维长链结构。晶体结构研究表明,该晶体属于三斜晶系,空间群Pi:a=8.955(2)A,b=10.758(2)A,c=10.855(2)A,a=70.56(3)°,β=69.25(3)°,γ=81.02(3)°,v=921.4(3)A^3,z=2,Dc=1.791g/cm^3,μ=1.470mm^-1,Mr=496.92, 相似文献
3.
本文用我们计算的氢原子与惰性气体原子间的相互作用势,系统地研究了低能(0.4-50weV)情况下在0°-180°范围,氢原子被惰性气体原子弹性散射,角分布的计算值与查到的实验值基本一致。 相似文献
4.
鄂东南晚二叠世大隆组层状硅质岩成因地球化学及沉积环境 总被引:6,自引:0,他引:6
鄂东南地区的晚第二叠世大隆组中存在数层与地层融合产生的薄层状硅质岩,其微量元素,微量元素,稀土元素,硅和氧同位素地球化学特征表明其为热水沉积硅基岩,Al-Fe-Mn和Fe-Mn-(Ni+Co+Cu)三角图上,硅质岩属较典型的热水沉积硅质岩,硅质岩MnO/TiO2〈0.5,δCe平均值为0.80,δ^30Si值为0.3×10^-3~0.7×10^-3,表明本区晚二叠世大隆组层状硅质岩主要在浅海环境下 相似文献
5.
广西凭祥逆冲推覆构造的发现及意义 总被引:4,自引:2,他引:4
凭祥逆冲推覆构造是广西境内首次在上古生办地台盖层中发现的大型叠瓦状逆冲推覆构造。长度〉30km,总体走向25°-40°,断面倾向南东,倾角20°-30°,逆冲方向307°-310°,分带特征明显。经平衡剖面复原计算其缩短率e=033.3%,相对长度比εγ=66.7%,推覆蹁〉5600m。 相似文献
6.
产于凹凸棒石粘土矿层中的硅岩具有特征的沉积构造,SiO2含量高(77.92 ̄89.44%),U/Th〉1、Zn、As、Sb等元素含量高,稀土总量低(4.5×10^-6 ̄16.55×10^-6)。稀土配分型式及氧稳定同位素组成与热水沉积硅岩一致,推算形成温度为71℃ ̄81℃。上述特征表明硅岩为热水沉各位产,亦说明在苏皖凹凸棒石粘土矿床形成过程中存在有热水事件。 相似文献
7.
通过实验,在温差从10℃到90℃,夹层间距从0.01m至0.08m,空气层与水平面夹角在0°~90°变化范围内,全面分析了夹层温差、夹角、Re数、间距、纵深比等因素对换热的影响.拟合出了各角度下的准则方程式,并在θ>60°时,用(1-θ/18O)n来体现角度变化对换热的影响,避免出现90°时准则式与其它角度下形式无法统一的问题.分析了一定温差、角度下对流换热量随间距的变化关系,给出了最佳间距,从而为工程计算提供了理论依据. 相似文献
8.
研究了影响SBS 溶剂型压敏胶粘剂性能的因素,结果表明:溶剂和增粘树脂种类软化剂用量影响最大.实验所得制品在某些性能上(180°剥离强度 1150~1270 N/m持粘力 27~51h)超过文献中同类制品值. 相似文献
9.
采用两种不同的方法合成了一种新的铬(Ⅲ)四苯基卟啉配合物,2,4-(O2N)2C6H3OCr(Ⅲ)TPP·THF(A)(TPP=tetraphenylpor phyrin).对其进行了元素分析和红外、紫外可见、核磁表征,并对其晶体进行了X射线分析. 相似文献
10.
研究了在吐温-40存在下,用4,5-二溴邻硝基苯基萤光酮(DBON-PF)在1.1~1.3mol/L盐酸介质中测定微量钼的方法。在540nm处测得表观摩尔吸光系数为9.5×104L·mol-1·cm-1.钼的含量在0~14μg/25mL的范围内,符合比耳定律。大多数常见阳离子不干扰,用本法测定了合金钢中的微量钼,获得了满意的结果。 相似文献
11.
通过对苏北地区盐城、连云港市7-18岁中、小学生5项身体素质抽样调查数据均值的比较研究,分析了当前城乡青少年身体素质的基本发展状况,并且有针对性地就学校体育工作的开展提出了相应的科学性建议和对策。 相似文献
12.
徐莉 《武汉理工大学学报(材料科学英文版)》2009,24(3):354-358
Nanocomposites MgFe2O4/SiO2 were successfully synthesized by the sol-gel method in the presence of N, N-dimethylformamide (DMF). The formation of pure MgFe2O4 was confirmed by powder X-ray diffraction (XRD) and electron diffraction. The structural evolution of MgFe2O4 nanocrystals was followed by powder X-ray diffraction and IR absorption spectroscopy. The formation of spinel structure of
MgFe2O4 started at 800 °C, and completed at 900 °C. The transmission electron microscopy (TEM) measurements suggest that the particle
sizes increase with the increasing annealing temperature, and the mean particle sizes of the spherical samples annealed at
800 °C, 900 °C and 1 050 °C are ca. 3 nm, 8 nm and 11 nm, respectively. Magnetization measurements at room temperature and 78 K indicate superparamagnetic nature
of these MgFe2O4 nanocrystals.
Funded by the National Natural Science Foundation of China(No. 30771676), the Natural Science Foundation of Jiangsu Province
(No. BK20081842), and the Foundation of Nanjing Bureau of Personal for the Returned Overseas Chinese Excellent Scholars 相似文献
13.
Formation and coexistence of tricalcium silicate (C3S) and calcium sulphoaluminate (C4A3
) minerals in Portland cement clinker containing calcium sulphoaluminate were investigated. The f-CaO content, mineral composite and formation of mineral in the clinker were analyzed respectively by chemical analysis, differential
scanning calorimetry(DSC) and X-ray diffraction. The results show that, adding a suitable amount of BaO can improve the burnability
of raw meal and promote the f-CaO absorption. Tricalcium silicate and calcium sulphoaluminate minerals can form and coexist in clinkers at 1 234–1 317
°C by the addition of BaO to the raw meal. A suitable amount of BaO expanded the coexistence temperature of two minerals by
58 °.
Funded by the National Basic Research Program of China (No. 2009CB623100), National Eleven Five-Year Scientific and Technical
Support Plans (No. 2006BAF02A24), the Natural Science Fund for Colleges and Universities in Jiangsu Province(No. 08KJB430006),
the Open Fund for the Key Laboratory of Inorganical and Composite Materials in Jiangsu Province(No. wjjqfhxc1200801) and the
Innovation Fund of Doctoral Dissertation of Nanjing University of Technology (No. BSCX200705) 相似文献
14.
赵学群 《吉林化工学院学报》2014,31(10):111-114
信息化建设在改革高职教育人才培养模式、推进高职教育教学改革、提高高职教育办学质量、建立现代高职教育体制等方面发挥明显的推动作用。在调查研究基础上,通过对他校先进经验的借鉴,江苏省连云港财经高等职业技术学校在数字化校园建设实践中,进行了创新发展,对高职院校信息化建设的基本思路与途径进行了探索尝试。 相似文献
15.
郭伟 《武汉理工大学学报(材料科学英文版)》2009,24(2):326-329
On the basis of analyzing coal gangue’s chemical and mineral compositions, the structure change of coal gangue during the
mechanical activation was investigated by XRD, FTIR, NMR, and the mechanical strength of the cement doped coal gangue with
various specific surface area was tested. The experimental results indicate that, the lattice structure of metakaolin in coal
gangue samples calcined at 700 °C disorganizes gradually and becomes disordered, and the lattice structure of α-quartz is distorted slightly. The pozzolanic activity of the coal gangue increases obviously with its structural disorganization.
Funded by the Key Laboratory Foundation of Ecological-Environment Materials (Yancheng Institute of Technology) of Jiangsu
Province (XKY2006020), and the Natural Science Foundation of Jiangsu Provincial Education Department(07KJB430123) 相似文献
16.
首先构建了地级城市竞争力评价指标体系,然后运用统计分析软件(SPSS)对原始数据进行分析处理,得出地级城市竞争力综合评价模型,并通过该模型对江苏省13个地级市竞争力进行了综合评价,结论是南京、苏州、无锡城市竞争力最强,常州、南通较强,镇江、扬州、徐州一般,泰州、连云港、盐城较弱,淮安、宿迁最弱。该计算结果为连云港市制定切实有效的促进经济、社会发展的规划和措施提供了参考。 相似文献
17.
18.
魏宝刚 《西北工业大学学报》1998,16(1):7-11
分布式问题求解是分布式人工智能研究和应用的一个重要分支,如何使各个只有局部的,不完全知识的知识源协主财工作、合作求解问题是它的一个最基本也是最重要的研究内容之一。 相似文献
19.
BAI Jiahai GUO Lucun 《武汉理工大学学报(材料科学英文版)》2006,21(3):100-102
Cordierite honeycomb ceramics was treated with 1.5 M HNO3 , followed with 1.5 M NaOH at 93 ℃. The combination of acid treatment with alkali treatment significantly diminished the rebounding of coefficient of thermal expansion (CTE) caused by heat treatment, a phenomenon observed in samples treated solely with acid. Inductively coupled plasma (ICP) analysis results reveal that the alkali treatment preferentially dissolved "free" SiO2 left in the acid-treated samples, which is considered to be a key factor responsible for the CTE rebounding. 相似文献