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Search Results: 1 - 10 of 118336 matches for " 俞家文 "
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土茯苓对棉酚的解毒作用
王文华,,周志仁,陈昭,赵南江,李瑶卿
中国中药杂志 , 1982,
Abstract: <正>动物实验和临床试用表明,口服棉酚有良好的灭精作用,是一个有希望的男用节育药,但尚有一定的毒付作用。据古代文献记载:“棉子性味辛热有毒”。《本草从新》记述:“子油辛热微毒”。因此,启发人们从清热解毒中药中寻找棉酚解毒药。据报道,人类长期服粗棉油,可发生烧热病,而中医的临床治疗则以清热解毒,养
α―松油烯的研制
张晋康,,雪英,
南京林业大学学报(自然科学版) , 1990, DOI: 10.3969/j.jssn.1000-2006.1990.03.006
Abstract: <正>本文研究了在不同的催化条件下,以马尾松脂松节油为原料,制取α-松油烯的工艺条件。试验结果表明,以酸催化,在反应温度50℃、反应时间7h、酸浓度52%、h~+:松节油=0.3:1(摩尔比)的反应条件下,异构产物中α-松油烯的含量可达45%以上,α-松油烯的得率40%以上。初探了以阳离子树脂催化,在反应温度95℃、反应时间35h、树脂:松节油=0.2:1(重量比)的反应条件下,α-松油烯的得率达33.5%。
福建集体林权改革中的金融创新与对策
贾卫国,小平,,姚萍,
南京林业大学学报(自然科学版) , 2008, DOI: 10.3969/j.jssn.1000-2006.2008.02.027
Abstract: 在对福建在集体林权改革过程中金融创新经验总结的基础上,指出了目前存在的金融产品与林业生产特点不匹配、商业银行具体针对性地管理办法不够健全,以及林业服务体系不完善等问题限制了林权抵押贷款的金融手段运用o提出了完善政策法规体系、创新信贷产品、建立社区信贷组织、金融部门完善管理制度、林业部门加强服务等建议和措施。
多孔纳米CoFe2O4的制备及其对高氯酸铵的热分解催化性能
Preparation of Nanoporous CoFe2O4 and Its Catalytic Performance during the Thermal Decomposition of Ammonium Perchlorate

,超(),春培,沈瑞琪,程佳,,秦志春
- , 2016, DOI: 10.3866/PKU.WHXB201605121
Abstract: 采用胶晶模板法制备出具有三维多孔结构的纳米CoFe2O4。利用X射线衍射仪(XRD)、傅里叶变换红外(FT-IR)光谱仪、扫描电镜(SEM)、透射电镜(TEM)和N2吸附-脱附对样品的晶型和形貌结构等进行表征,采用差示扫描量热法(DSC)对比研究多孔纳米CoFe2O4和球形纳米CoFe2O4对高氯酸铵(AP)的热分解性能的影响,并考察这两种催化剂对AP催化热分解的动力学参数。结果显示,制备出的多孔纳米CoFe2O4样品具有典型的尖晶石结构,孔径约200 nm;比表面积明显高于40 nm球形CoFe2O4,达到55.646 m2·g-1。DSC测试结果表明:多孔纳米CoFe2O4的加入促进了AP的热分解,最高使AP的高温分解峰温降低91.46℃,能量释放最高达1120.88 J·g-1,是纯AP分解放热量的2.3倍;多孔纳米CoFe2O4具有较高的比表面积,能提高催化反应的接触面积,使AP的高温分解峰温度更低,反应活化能较小,从而表现出比球形纳米CoFe2O4更高的催化活性。此外,对多孔纳米CoFe2O4催化AP的热分解机理进行初步探索,纳米多孔催化剂对气态中间产物的作用促进了AP的热分解。
Three-dimensional, nanoporous CoFe2O4 catalysts were synthesized, employing a colloidal crystal template method. X-ray diffraction (XRD), Fourier transform infrared (FT-IR) spectroscopy, scanning electron microscopy (SEM), transmission electron microscopy (TEM), and N2 adsorption-desorption were subsequently used to characterize the crystal structures and morphologies of the samples. The catalytic activities of nanoporous CoFe2O4 and CoFe2O4 nanospheres during the thermal decomposition of ammonium perchlorate (AP) were also investigated by differential scanning calorimetry (DSC). The results show that the spinel framework of these materials has an ordered open network of pores averaging 200 nm in diameter. The specific surface area of the nanoporous CoFe2O4 was 55.646 m2·g-1, a value that was higher than that of the nanosphere material. DSC analysis indicates that the catalytic activity of the nanoporous CoFe2O4 is superior to that of the spherical material during the thermal decomposition of AP, and that the nanoporous catalyst makes the peak temperature of high temperature decomposition decrease by 91.46℃. The heat release from the AP in the presence of nanoporous CoFe2O4 (1120.88 J·g-1) is 2.3 times that obtained frompureAP. Both the higher specific surface area and greater quantity of active reduction sites on the nanoporous CoFe2O4 relative to the nanosphere material act to reduce the activation energy during the AP decomposition process. Based on the results of this work, a possible catalytic mechanismfor the thermal decomposition of AP over nanoporous CoFe2O4 is proposed, in which gaseous intermediates play an important role
Research of RFID information service based on cloud computing in supply chain
基于云计算的供应链RFID信息服务研究*

LIANG Chang-yong,LU Xin,YU Jia-wen,LU Wen-xing,
梁昌勇
,陆鑫,,

计算机应用研究 , 2011,
Abstract: Given the problems of existing EPCGlobal network and the demand of information service under supply chain environment,this paper provided an innovative architecture for RFID information service based on cloud computing. This architecture decoupled the local enterprise RFID application from public information service, built a unified cloud-based RFID information service platform with using an information distribution mechanism based on hidden markov model (HMM) to mirror RFID information, finally implemented near real-time, serial-level RFID information service. Finally, compared the architecture with the EPCGlobal network and proved its superiority.
紫翅椋鸟的生态观察

动物学杂志 , 1987,
Abstract:
水泥基复合材料中纤维拉拔的变位约束细观力学模型
,刘琼阳
复合材料学报 , 2008,
Abstract: 从细观尺度研究受拉水泥基复合材料中倾斜纤维的桥联行为,以分析承受轴向拉伸的随机各向分布纤维增强混凝土的力学性能。将单根随机纤维的理论解在三维空间进行积分运算有效描述受拉纤维混凝土的受力过程。给出了拉拔力、拉拔总功与裂纹张开位移和纤维倾斜角的函数关系。结果表明,增加纤维的倾斜角度会降低纤维的裂纹桥联力,拉拔力和拉拔总功的理论计算结果与试验结果有较好的一致性。
挖掘Web日志中连续可重复频繁访问路径的新算法
周晟,
福州大学学报(自然科学版) , 2007,
Abstract: 提出了一种从Web日志中快速挖掘连续可重复频繁访问路径的新算法ICAP.该算法通过构造以频繁项目p为根的SAP树,能一次挖掘出所有以p为前缀的连续可重复频繁访问路径.最后通过实验验证了算法的正确性和有效性.
基于分类排名的网站可信度分析
黄晞,
福州大学学报(自然科学版) , 2013,
Abstract: 提出一种考虑网站分类排名的可信度分析算法,即在分析可信度时,通过引入训练集,对不同类别的信息进行分析,再利用分类信息来提高网站可信度分析的结果. 实验结果表明,改进后的算法可以提高可信度分析结果的实用性和准确性.
人眼对彩色正弦光栅的对比敏感性及其适应后效

心理学报 , 1981,
Abstract: 实验中采用电视显示法以测定人眼对彩色正弦光栅的对比敏感性,并通过彩色正弦光栅选择性适应后效的试验来阐明空间频率通道和色通道之间的相互关系。实验结果表明:1.人眼在2°视角间视状态下对不同彩色正弦光栅的对比敏感性有差别,绿色光栅的对比敏感性比蓝、红色高。对彩色正弦光栅的对比敏感性在低频处有衰减。2.人眼在2°视角时对彩色正弦光栅的空间适应范围和最低空间频率通道的位置均在0.8周/度处。彩色光栅(0.8周/度至3.5周/度)适应后效的带宽具有明显的非对称性。3.彩色光栅的适应后效主要决定于亮度的空间频率通道,但色通道的影响也是存在的。
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