排序方式: 共有11条查询结果,搜索用时 15 毫秒
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CAI Guang-Yu LlU Zhong-Min SHI Ren-Min HE Chang-Qing YANG Li-Xin SUN Cheng-LinDalian Institute of Chemical Physics Acadernia Sinica Dalian Iiaorting 《天然气化学杂志》1995,(2)
A new route named as SDTO method for the synthesis of lightolefins from syngas has been proposed.That is to convert syngas todimethylether and then to convert dimethylether to light olefins.The catalystsfor the two conversion reactions have been developed.For the first reaction,the catulySt was synthesized by the combination of methanol synthesis catalystwith γ-Al_2O_3or zeolites which possesses both metallic and acidic functions.Thecatalyst for the second reaction was modified SAPO-34 molecular sieve.Thevariables of the reactions have also been investigated.The results from theserial connection of the two conversion steps without any separation show thatthe yield of C_2~-C_4~- olefins Could be>100g/(m~3 syngas). 相似文献
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税企博弈模型的再研究 总被引:6,自引:1,他引:5
刘京娟 《数学的实践与认识》1998,(4)
本文以文[1]基础,在更一般条件下提出了税企博弈模型,得到新的骗税罚款系数公式.从理论上证明了税务机关对企业抽样检查与全面检查具有相同的经济效果.最后,给出建模应注意的几个问题. 相似文献
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刘权 《影像科学与光化学》1987,5(3):1-6
本文测定了依尔福染料黑白片XP1 400在XPI套药中冲洗的染料影像及中间银影像的均方根粒度,同时又测定了在同样曝光条件下的涂层在普通黑白显影液中冲洗的黑白银影像的均方根粒度。结果表明,三种影像粒度随密度变化的规律完全不同。本文又用selwyn公式计算了中间银影像及黑白银影像的单位面积显出颗粒数,测试和计算结果表明,与黑白银影像比较,中间银影像具有均方根粒度明显低和单位面积显出颗粒数高的特点。这与光学显微镜下现察到的中间银影像及黑白银影像的形态是一致的。本文还根据实验及计算结果讨论了DIR成色剂在影像形成过程中的作用。 相似文献
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近几年来,由于各种“软”电离技术的发展和应用「‘,’‘,为利用质谱分析生物大分子提供了一条十分有效的途径[‘j,其中基体辅助激光解吸电离飞行时间质谱法(MALDI-TOF-MS)是最有前途的技术之一D‘.钙调素(CaM)是动植物中普遍存在的多功能的胞内钙受体蛋白,参与调控许多生理反应[”.最近几年也在细胞外区域发现了钙调素及其功能[”.钙调素分子量的准确、快速测定是钙调素性质、结构和功能研究的首要问题.目前CaM分子量的测定大多采用SDS-PAGE、凝胶过滤和沉淀平衡等方法,例如对牛脑CaM分子量的SDS-PAGE测… 相似文献
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采用提拉法制备了Gd3Ga5-xAlxO12(以下简称GGAG)单晶,经X射线粉末照相证实为石榴石型单相结构。在T=1.5—77K温区里,场强从45—60000Oe范围内,沿[111]晶轴方向测量了磁化强度和磁化率,并与本文所用钇镓石榴石Gd3Ga5O12(以下简称GGG)和文献[1,2]报道的GGG单晶数据作了比较。实验结果表明:(1)在场强H<500Oe时,磁化率X与温度T的关系遵守居里-外斯定律,其有序温度TN远低于1.5K;(2)H>10000Oe时,该材料的磁化强度(或磁化率)比GGG高3—4%;(3)在H~30000Oe时,特定温度Tmin对应的临界场Hc比GGG约高4000Oe。实验研究表明,采用离子代换法寻找新的性能良好的磁致冷剂的途径是可行的。
关键词: 相似文献
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主要介绍了根据动态法测量原理设计的新型杨氏模量自动测量仪,此仪器创新性地采用全自动扫频技术,实现了金属材料杨氏模量的全自动测量,并且增加了虚假共振的判断和品质因素的测量,提高了测量结果的可靠性. 相似文献
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Chitosan resins, which clinically served as adsorbents in hemoperfusion therapy, were prepared with reversed-phase suspension methodology using three differently structured crosslinking agents, methanal, glyoxal and glutaraldehyde. And the glyoxal and glutaraldehyde crosslinked chitosan resins were reduced with NaBH4 afterwards. By analyzing the results from FTIR and SEM, it was found that the reduction treatment to the adsorbents efficiently improved the chemical stability of these chitosan resins, and the shifts in crosslinking agents exerted influences over the morphologies of the adsorbents obviously. After being put to use in the adsorption tests upon some model uremic middle molecular toxins and BSA in vitro, all three adsorbents demonstrated a fairly realistic adsorption capability to the model toxins but little to BSA. And the adsorption process reached the equilibrium in a clinically qualified short time. But the adsorption capacities of these adsorbents to the model toxins were quite different. It 相似文献
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刘权 《影像科学与光化学》1987,5(1):30-33
本文研究了卤化银颗粒受到外界拉力后,对D-logER曲线在负感区域的影响。在指定的曝光量下,拉力破坏使表面影像密度增加。对照相应的显微照片观察,显示了外力引起潜影加强的事实。就此结果,用位错和陷阱在颗粒上的重新分布进行了讨论。另一组显微照片显示出在负感区,随着曝光量的增加卤化银颗粒内部光解银渐增。 相似文献
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The supramolecular assembly of bis[3, 4, 12, 13, 21, 22, 30, 31-octa(dodecylthio)-2, 3-naphthalocyaninato] erbium complex (Er[Nc(SC12H25)8]2) was fabricated at the air/water interface by Langmuir monolayer technique. Surface pressure-area isotherm indicates that stable monolayer is formed. The monolayer morphology on mica was investigated by atomic force microscopy (AFM). Columnar domains of ca. 100 nm ×(20-30) nm appearing in the micrograph have ordered orientation. Polarized UV-vis spectra and small-angle X-ray diffraction pattern show that the macrocycles tilt in the monolayer. The orientation angle of the naphthalocyanine ring with respect to the substrate was found to be ca. 54°. Each monolayer is ca. 3.53 nm thick. The columnar domain comprises 4-6 rows of columnar supramolecular assemblies where the molecules stack face-to-face. 相似文献