全文获取类型
收费全文 | 54篇 |
免费 | 9篇 |
国内免费 | 4篇 |
专业分类
化学 | 28篇 |
晶体学 | 5篇 |
力学 | 6篇 |
综合类 | 1篇 |
数学 | 18篇 |
物理学 | 9篇 |
出版年
2024年 | 1篇 |
2023年 | 1篇 |
2022年 | 4篇 |
2021年 | 4篇 |
2020年 | 1篇 |
2019年 | 1篇 |
2018年 | 1篇 |
2017年 | 1篇 |
2015年 | 2篇 |
2014年 | 1篇 |
2013年 | 2篇 |
2012年 | 2篇 |
2011年 | 3篇 |
2010年 | 1篇 |
2009年 | 5篇 |
2008年 | 5篇 |
2007年 | 2篇 |
2006年 | 1篇 |
2005年 | 2篇 |
2004年 | 3篇 |
2003年 | 2篇 |
2002年 | 6篇 |
2001年 | 5篇 |
2000年 | 2篇 |
1999年 | 2篇 |
1998年 | 1篇 |
1997年 | 2篇 |
1996年 | 1篇 |
1995年 | 1篇 |
1994年 | 1篇 |
1986年 | 1篇 |
排序方式: 共有67条查询结果,搜索用时 78 毫秒
31.
指数分布位置参数和分位点的估计 总被引:2,自引:0,他引:2
§1 引言 设随机变量X服从指数分布E(u,σ),具有密度函数 此处-∞相似文献
32.
Reactions of 1,4-dilithio-1,3-dienes with DMF afforded multiply substituted stereodefined cis,cis-2,4-diene-1,6-dials in high yields. Treatment of these 1,6-dials with LiAlH4 or RLi resulted in the formation of their corresponding 1,6-diols. These bifunctional compounds, cis,cis-2,4-diene-1,6-dials and -1,6-diols are otherwise not readily available. Further reaction of these 1,6-diols with an aldehyde catalyzed by strong acids led to the formation of oxacycles of novel structures. 相似文献
33.
乙醇一步合成乙酸乙酯Cu/ZnO/NiO/Al2O3催化剂的催化性能及其表征郑荣辉a曾金龙a傅锦坤b(a.厦门大学化工系b.化学系厦门361005)关键词一步合成法乙酸乙酯混合氧化物催化剂TPR和TPD中图分类号O623.426.2作为重要化工产品的... 相似文献
34.
Jinglong Tang Ling Xiong Jianyu Wang Jiage Li Tingfei Xi 《Applied Surface Science》2008,255(2):502-504
Nanosilver has been widely used in medical biology; however, the distribution and interaction of nanosilver with cells is still unclear. There have been some reports demonstrating that nanoparticles can cross the blood-brain barrier (BBB). The present study investigated the accumulation of silver nanoparticles in the brain, and the effects of silver nanoparticles on BBB. Nanosilver and microsilver (62.8 mg/kg) particles were subcutaneously injected into rats. The rats were sacrificed at predetermined time points and the brains were obtained for ultrastructural observation and silver level detection. The results showed that silver nanoparticles could traverse the BBB and move into the brain in the form of particle. The silver nanoparticles can induce neuronal degeneration and necrosis by accumulating in the brain over a long period of time. 相似文献
35.
36.
基于遗传算法的云计算资源调度策略研究 总被引:1,自引:0,他引:1
对云计算环境中的资源调度问题进行了研究,鉴于当前云计算环境中资源利用率不高,节点负载不均衡的问题,提出了一种新的基于遗传算法的关于虚拟机负载均衡的调度策略。根据历史数据和系统的当前状态以及通过遗传算法,该策略能够达到最佳负载均衡和减少或避免动态迁移,同时还引入了平均负载来衡量该算法的全局负载均衡效果。最后通过在CloudSim平台进行仿真实验,结果表明,该策略具有相当好的全局收敛性和效率,当系统虚拟机被调度之后,算法在很大程度上能够解决负载不均衡和高迁移成本问题,并且极大地提高了资源利用率。 相似文献
37.
Hui Liu Yanhong Xu Shihui Wen Qian Chen Dr. Linfeng Zheng Prof. Mingwu Shen Prof. Jinglong Zhao Prof. Guixiang Zhang Prof. Xiangyang Shi 《Chemistry (Weinheim an der Bergstrasse, Germany)》2013,19(20):6409-6416
We report a facile approach to fabricating low‐generation poly(amidoamine) (PAMAM) dendrimer‐stabilized gold nanoparticles (Au DSNPs) functionalized with folic acid (FA) for in vitro and in vivo targeted computed tomography (CT) imaging of cancer cells. In this study, amine‐terminated generation 2 PAMAM dendrimers were employed as stabilizers to form Au DSNPs without additional reducing agents. The formed Au DSNPs with an Au core size of 5.5 nm were covalently modified with the targeting ligand FA, followed by acetylation of the remaining dendrimer terminal amines to endow the particles with targeting specificity and improved biocompatibility. Our characterization data show that the formed FA‐modified Au DSNPs are stable at different pH values (5—8) and temperatures (4–50 °C), as well as in different aqueous media. MTT assay data along with cell morphology observations reveal that the FA‐modified Au DSNPs are noncytotoxic in the particle concentration range of 0–3000 nM . X‐ray attenuation coefficient measurements show that the CT value of FA‐modified Au DSNPs is much higher than that of Omnipaque (a clinically used CT contrast agent) at the same concentration of the radiodense elements (Au or iodine). Importantly, the FA‐modified Au DSNPs are able to specifically target a model cancer cell line (KB cells, a human epithelial carcinoma cell line) over‐expressing FA receptors and they enable targeted CT imaging of the cancer cells in vitro and the xenografted tumor model in vivo after intravenous administration of the particles. With the simple synthesis approach, easy modification, good cytocompatibility, and high X‐ray attenuation coefficient, the FA‐modified low‐generation Au DSNPs could be used as promising contrast agents for targeted CT imaging of different tumors over‐expressing FA receptors. 相似文献
38.
Abdul-Hussein SaberAL-MOUEL WangJinglong 《高校应用数学学报(英文版)》2004,19(4):435-448
The one-way multivariate repeated measurements analysis of variance (1-way MRM ANOVA) model for complete data and the sphericity test are studied. 相似文献
39.
盐酸滴定碳酸钠第二化学计量点碳酸的浓度是溶液的pH值的计算依据,碳酸的浓度应该根据等物质的量反应原理,利用反应溶液的浓度具体计算得出,同时,应该明确说明计算时忽略碳酸的分解这一前提条件。 相似文献
40.