全文获取类型
收费全文 | 1505篇 |
免费 | 13篇 |
国内免费 | 30篇 |
专业分类
教育 | 815篇 |
科学研究 | 203篇 |
各国文化 | 10篇 |
体育 | 370篇 |
综合类 | 10篇 |
文化理论 | 4篇 |
信息传播 | 136篇 |
出版年
2024年 | 6篇 |
2023年 | 3篇 |
2021年 | 6篇 |
2016年 | 3篇 |
2015年 | 5篇 |
2014年 | 23篇 |
2013年 | 16篇 |
2012年 | 90篇 |
2011年 | 161篇 |
2010年 | 52篇 |
2009年 | 16篇 |
2008年 | 89篇 |
2007年 | 98篇 |
2006年 | 85篇 |
2005年 | 88篇 |
2004年 | 102篇 |
2003年 | 82篇 |
2002年 | 85篇 |
2001年 | 47篇 |
2000年 | 63篇 |
1999年 | 44篇 |
1998年 | 13篇 |
1997年 | 12篇 |
1996年 | 17篇 |
1995年 | 14篇 |
1994年 | 15篇 |
1993年 | 20篇 |
1992年 | 9篇 |
1991年 | 29篇 |
1990年 | 24篇 |
1989年 | 22篇 |
1988年 | 12篇 |
1987年 | 15篇 |
1986年 | 13篇 |
1985年 | 19篇 |
1984年 | 15篇 |
1983年 | 17篇 |
1982年 | 18篇 |
1981年 | 18篇 |
1980年 | 10篇 |
1979年 | 21篇 |
1978年 | 3篇 |
1977年 | 8篇 |
1976年 | 5篇 |
1975年 | 2篇 |
1974年 | 2篇 |
1958年 | 7篇 |
1955年 | 3篇 |
1948年 | 2篇 |
1938年 | 2篇 |
排序方式: 共有1548条查询结果,搜索用时 15 毫秒
11.
12.
13.
14.
Techtarget Todd R. Weiss 《信息系统工程》2005,(3):16
keystone公司长期停滞的ERP项目终于宣告成功, 系统将 130 个厂房,全美国2000 多员工连接在一起。回首keystone 信息化历程,其经验教训值得我们深思。 相似文献
17.
OBJECTIVE: The United States General Accounting Office (United States General Accounting Office [USGAO], 1989) report on out-of-home care affirmed that the foster care system is in crisis. To shed light on some factors that influence retention, the study reported here asked "What factors influence the satisfaction of foster parents?" and "What factors influence the intent of licensed foster parents to continue to foster?" METHOD: A sample of 539 foster parents in eight urban counties in a large Midwestern state completed questionnaires aimed at addressing these questions. RESULTS: Some of the factors exerting the strongest influence on satisfaction were: feeling competent to handle the children who were placed; wanting to take in children who needed loving parents; no regrets about investment in foster children; foster mother's age; and agency social worker providing information and showing approval for a job well done. An example of factors exerting influence on intent to continue to foster include overall satisfaction, readiness to phone the social worker, number of foster boys in the home, being treated like one needed help oneself, and agency affiliation (private). CONCLUSIONS: Efforts to increase the supply of foster homes through recruitment is not enough. The support, training, and professional regard given to parents after they have begun the fostering task is of greater need. Based on analysis of the findings, implications for practice, programming, and policy are offered. 相似文献
18.
Objective: A natural cyclic peptide previously isolated from Citrus medica was synthesized by coupling oftetrapep-tide units Boc-Leu-Pro-Trp-Leu-Ome and Boc-Ile-Ala-Ala-Gly-Ome after proper deprotection at carboxyl and amino terminals followed by cyclization of linear octapeptide segment.Methods: Solution phase technique was adopted for the synthesis of cyclooctapeptide--sarcodactylamide.Required tetrapeptide units were prepared by coupling of Boc-protected dipeptides viz.Boc-Leu-Pro-OH and Boc-Ile-Ala-OH with respective dipeptide methyl esters Trp-Leu-Ome and Ala-Gly-Ome.Cyclization of linear octapeptide unit was done by p-nitrophenyl ester method.The structure of synthesized cyclopolypeptide was elucidated by FTIR,1H NMR,13C NMR,FABMS spectral data and elemental analysis.The newly synthesized peptide was evaluated for dif-ferent pharmacological activities including antimicrobial,anthelmintic and cytotoxic activities.Results: Synthesis of sarcodac-tylamide was accomplished with >78% yield utilizing dicyclohexylcarbodiimide (DCC) as coupling agent.Newly synthesized peptide possessed potent cytotoxic activity against Dalton's lymphoma ascites (DLA) and Ehrlich's ascites carcinoma (EAC) cell lines,in addition to moderate anthelmintic activity against earthworms Megascoplex konkanensis,Pontoscotex corethruses and Eudrilus sp.Moreover,cyclopolypeptide displayed good antimicrobial activity against pathogenic fungi Candida albicans and Gram-negative bacteria Pseudomonas aeruginosa,in comparison to standard drugs griseofulvin and ciprofloxacin.Conclusion: Solution phase technique employing DCC and triethylamine (TEA) as base proved to be effective for the synthesis of natural cyclooctapeptide.N-methyl morpholine (NMM) was found to be a better base for the cyclization of linear octapeptide unit in comparison to TEA and pyridine. 相似文献
19.
王明达 杨金土 刘来泉 余祖光 高奇 Josie Misko Susan Dave Jorn Saunder 钱景舫 Friedhelm Eicker James R Stone 《中国职业技术教育》2006,(14)
全国教育科学“十五”规划国家一般课题《职业教育几个基本问题研究》(BJA010100)课题组就“职业教育的基本问题”对国内外职业教育界的专家、学者进行了访谈,使我们看到了对此问题的不同角度和层面的理解。这是一次思想的碰撞,有利于我们深化对职业教育基本问题的认识。本刊特将访谈记录分专题编辑处理,并从本期起连续刊发,本期论题为“职业教育是什么?” 相似文献
20.