全文获取类型
收费全文 | 524篇 |
免费 | 58篇 |
国内免费 | 84篇 |
专业分类
化学 | 551篇 |
晶体学 | 9篇 |
力学 | 9篇 |
综合类 | 5篇 |
数学 | 24篇 |
物理学 | 68篇 |
出版年
2023年 | 2篇 |
2022年 | 7篇 |
2021年 | 5篇 |
2019年 | 3篇 |
2018年 | 4篇 |
2017年 | 3篇 |
2016年 | 2篇 |
2015年 | 2篇 |
2014年 | 34篇 |
2013年 | 49篇 |
2012年 | 46篇 |
2011年 | 7篇 |
2010年 | 4篇 |
2009年 | 4篇 |
2008年 | 20篇 |
2007年 | 19篇 |
2006年 | 17篇 |
2005年 | 18篇 |
2004年 | 29篇 |
2003年 | 38篇 |
2002年 | 85篇 |
2001年 | 193篇 |
2000年 | 31篇 |
1999年 | 20篇 |
1998年 | 10篇 |
1997年 | 8篇 |
1996年 | 1篇 |
1995年 | 3篇 |
1986年 | 1篇 |
1982年 | 1篇 |
排序方式: 共有666条查询结果,搜索用时 15 毫秒
661.
WANG Wei WANG Yu-hong Li Wei * *Biological Macromolecular Laboratory College of Life Science Jilin University Changchun P. R. China 《高等学校化学研究》2002,18(4):491-494
IntroductionBioinformatics is coming with Human GenomeProject(HGP) . With the explosions of sequence,structural and other information available ,bioinformatics is playing an increasingly large rolein the study of fundamental biomedical problems.At present and in the near future,it is the mainchallenge for bioinformatists to make gene dicoveryand annotation of human genome sequences whenthe vast amount of data is produced by the highthroughput genome sequencing in a large scale andautomated m… 相似文献
662.
CHEN Wei YUAN Hong-ming JIANG Yu-sheng HUO Hua CHEN Jie-sheng *State Key Laboratory of Inorganic Synthesis Preparative Chemistry Jilin University Changchun P. R. China 《高等学校化学研究》2002,18(4):375-379
IntroductionSince Wilson and co- workers successfullysynthesized three- dimensional microporousaluminophosphates (Al PO4 - n ) [1] in the 1 980 s,much attention has been focused on the explorationof1 - D chain,2 - D layer and3 - D open- frameworkmetal phosphates from aqueous or non- aqueoussystems.The number of metals incorporated intothe frameworks of these materials is continuouslyincreasing and the metals include Be[2 ] ,Ga[3] ,In[4 ] ,Sn[5] ,Sb[6 ] ,and the transition metals Zn[7] ,Ni… 相似文献
663.
WU Shi-hua* * WEI Wei ZHU Chang-ying HUANG Wei-pingZHANG Shou-min ZHENG Xiu-cheng ZHANG Shu-hong ZHAO Wei-jun 《高等学校化学研究》2001,17(4):439-444
Co-Pd bimetallic catalysts immobilized with four kinds of resins with different specific areas were prepared by means of the solvated metal atom impregnation (SMAI) method. The results of the XRD and the magnetic measurement showed that as the specific area of the resin increased, the particle sizes of Co and Pd on the catalysts with the same metal content decreased, so the catalytic activity of the catalysts for the hydrogenation of diacetone alcohol as well as the reduction of oxygen on the fuel cell electrode increased. Below 140 , the conversion of diacetone alcohol increased as the reaction temperature increased, and above 140 , the conversion decreased because of the rupture of the resin. 相似文献
664.
IntroductionAmrinon,asyntheticbipyridinederivative,nonglycosideandnoncatecholaminecar-diotonicstimulant,iscurrentlyusedinthetreatmentoftheheartfailureandforcardiovascu-larsupportinpediatricpatients.Itpossessespotentcardiacandbloodvesselspreadingef-fe… 相似文献
665.
Weinan E~* Jianfeng LU~ 《数学年刊B辑(英文版)》2007,28(6):665-676
The authors consider the simplest quantum mechanics model of solids,the tight binding model,and prove that in the continuum limit,the energy of tight binding model converges to that of the continuum elasticity model obtained using Cauchy-Born rule.The technique in this paper is based mainly on spectral perturbation theory for large matrices. 相似文献
666.
<正>1 问题提出挑战性学习内容是基于学生已有的知识经验,立足于学生的“最近发展区”,设计的具有一定难度的学习内容.挑战性学习内容能够帮助学生拓展视野,锻炼思维能力,促进对知识的理解,引导他们逐渐形成探寻真理的科学精神.那么,在教学中应该如何合理、科学地设计挑战性学习任务呢?倘若课程内容难度较低,就无法激发学生的学习兴趣,难以调动学生的思维和引发学生的深层次思考,不利于促进学生产生内在的学习动力.但是,如果课程内容难度过大, 相似文献