首页 | 本学科首页   官方微博 | 高级检索  
文章检索
  按 检索   检索词:      
出版年份:   被引次数:   他引次数: 提示:输入*表示无穷大
  收费全文   59375篇
  免费   979篇
  国内免费   1164篇
教育   34449篇
科学研究   11261篇
各国文化   213篇
体育   3500篇
综合类   2715篇
文化理论   557篇
信息传播   8823篇
  2024年   5篇
  2023年   41篇
  2022年   561篇
  2021年   1343篇
  2020年   952篇
  2019年   497篇
  2018年   2689篇
  2017年   2608篇
  2016年   2083篇
  2015年   1741篇
  2014年   2648篇
  2013年   3318篇
  2012年   3845篇
  2011年   4776篇
  2010年   4576篇
  2009年   3699篇
  2008年   3897篇
  2007年   4806篇
  2006年   3730篇
  2005年   3245篇
  2004年   1965篇
  2003年   1732篇
  2002年   1409篇
  2001年   1232篇
  2000年   841篇
  1999年   810篇
  1998年   563篇
  1997年   416篇
  1996年   333篇
  1995年   216篇
  1994年   203篇
  1993年   167篇
  1992年   150篇
  1991年   97篇
  1990年   38篇
  1989年   69篇
  1988年   27篇
  1987年   15篇
  1986年   37篇
  1985年   18篇
  1984年   27篇
  1983年   24篇
  1982年   9篇
  1981年   4篇
  1980年   5篇
  1979年   7篇
  1976年   3篇
  1974年   3篇
  1957年   21篇
  1951年   9篇
排序方式: 共有10000条查询结果,搜索用时 15 毫秒
951.
INTRODUCTION Modification of knots of a B-spline curve changes the shape of the curve. In some recent pub-lications (Juhász and Hoffmann, 2001; 2003; Hoff-mann and Juhász, 2004; Li and Wang, 2005), the authors studied the effect of the alteration of a single knot on the shape of the curve. Hoffmann (2004) and Li & Wang (2006) applied these theories into the constrained shape modification of B-spline and NURBS curves. Juhász (2001) and Hoffmann & Ju-hász (2005) studied the effe…  相似文献   
952.
没有感情的设计是空洞的,没有理智的设计是无用的,有情感有理智的设计才是完整的设计。金属材质的手机以理性、功能化为前提,适应了现在追求是科技的理念,又不失给人情感内在、广义的想象空间,顺应了时尚的潮流。将金属作为其材质的手机述说了引起世人共鸣的语言,它是属于一种内在的、广义的语言。情感品质所追求表达的是与人的经验类似的东西,手机的金属材质看似理智的一种设计,但给人一种想象的空间,有着情感化的语言,看似理智与情感的矛盾,却又那么协调的共融。  相似文献   
953.
对高职高专经贸类专业课程整合的思考   总被引:2,自引:0,他引:2  
高职经贸类专业必须按照培养目标要求,坚持以就业为导向、以能力为本位的原则进行课程整合,从而使经贸人才的培养与市场需求相吻合.  相似文献   
954.
政论学以日本留学生的创作为世纪先锋,奠定了中国人社科的激进传统。留学生政论学试图构思爱国主义的正面理论,并且释放新民政治的强烈变革感情.提倡积极参与政治管理的人精神,是中国集权体制和官本位化社会所欠缺的。  相似文献   
955.
按常规方法制备抗鸡传染性法氏囊炎卵黄抗体(yolkantibody,YA),经冻融、温度、机械振荡、光照和防后剂(0.01%流柳汞、0.01%叠氮钠和0.5%苯酚)等处理后测定其琼脂扩散试验(Agargelnredritation,AGP)效价的变化.实验结果表明,冻融毛次后卵黄抗体的AGP效价自1:64降至1:32,冻融6次降至1:16,0.5%苯酚的存在使YA的AGP效价自1:64降至1:16;其它物理因素对YA的AGP效价影响不明显.  相似文献   
956.
Antenna is very crucial to radiotelemetry capsules which can measure the physiological parameters of the gastroin- testinal (GI) tract. The objective of this paper is to design a novel spiral slots microstrip patch antenna for the radiotelemetry capsules communicating with external recorder at 915 MHz located in ISM (Industry, Science, and Medical) bands. The microstrip patch antenna is designed and evaluated using the finite-difference time-domain (FDTD) method. Return loss characteristics and the effect of the human body on resonant frequency are analyzed, and the performances of radiation patterns at different positions of the human alimentary tract are also estimated. Finally, specific absorption rate (SAR) computations are performed, and the peak 1-g and 10-g SAR values are calculated. According to the peak SAR values, the maximum delivered power for the designed antenna was found so that the SAR values of the antenna satisfy the ANSI (American National Standards Institute) limitations.  相似文献   
957.
Objective: We aim to describe the environment iodine concentration in salt, water and soil along Zhejiang Province coast in the China foreland. It will be helpful for us to judge whether this area is insufficient in iodine and universal iodized salt is necessary or not. Methods: We collected iodized salt samples, drinking water samples (tap water in the towns, and well water or spring water in the villages), water samples from different sources (ditches, lakes, rivers) and soil samples through random sampling in June, 2005. Salt, water and soil iodine was detected by arsenic-cerium redox method. Statistical analysis was expressed as mean±SEMby Windows SPSS 13.0. Results: (1) The iodine concentration in salt was 27.9±4.33 mg/kg (n=108). (2) Seventy-five water samples were collected. The water iodine value was 0.6~84.8 μg/L (mean of 11.66 μg/L). The watershed along the Qiantang River has significantly higher iodine content than the water in Lin'an in mountain area (P<0.01). The iodine content and mean iodine content of tap water, well or spring water and natural water sources were 4.30±2.43 μg/L (n=34), 23.59±27.74 μg/L (n=19)and 12.72±10.72 μg/L (n=22) respectively. This indicated that among environmental water sources, the ditch iodine content was the highest with river water iodine being the lowest (P<0.01). (3) Soil iodine value was 0.11~2.93 mg/kg (mean of 1.32 mg/kg).Though there was no statistical difference of soil iodine in different districts (P=0.131), soil iodine content correlated positively with water iodine content. Conclusion: Iodine concentration in salt accords with national policy of adding iodine in salt. Foreland has more iodine in water than mountain area. The data reflected that water and soil iodine in foreland area was not high, which suggests universal iodized salt should be necessary. Environment iodine has relatively close association with pollution.  相似文献   
958.
思想政治教育传统的主客二分思维方式把人抽象化、实体化,导致对受教育者真实需求的忽略和教育内容、教育方式的呆板滞后,不能实现个人与社会、政治教育和全面发展教育的协调,从而使思想政治教育改革不能取得令人满意的效果。马克思“现实的个人”思想是对传统实体化抽象人性观的变革,有利于消解与变革思想政治教育旧的思维方式,真正体现出教育的以人为本,确保思想政治教育改革取得更大的实效。  相似文献   
959.
There is a lack of systematic research on the training of clinicians toward providing counselling services and support to individuals with Fetal Alcohol Spectrum Disorder (FASD). The aim of this qualitative project was twofold: (1) to develop and pilot a clinical consultation process that would address clinicians’ reported need for greater communication and information sharing in serving clients affected by FASD; and (2) to build a model of FASD-informed clinical counselling practice by examining this consultation process and by capturing the experiences of clinicians who were involved. Findings from focus groups and meeting minutes are reported with respect to the model’s focus on reflection, communication, and action.  相似文献   
960.
在不考虑月经周期的情况下连续灌喂氯地酚5天,每天50mg,第8天肌注hCG2000IU,对猕猴具有一定的卵泡超数发育作用,最多可使双侧卵巢共24个卵泡发育,最大卵泡直径5—6mm,但不同个体反应变化较大。FSH hCG超排方案(考虑或不考虑月经周期,连续肌注FSH6天,共80—90IU,第8天肌注hCG2500IU)比氯地酚效果较好,最多可使双侧卵巢共28个卵泡发育,卵泡最大直径10mm,另外在1只猕猴观察到5个卵泡破裂将卵排出。电刺激采得之猕猴精子经洗涤后与用以上两种超排方案以卵泡吸得之卵子一同输入兔输卵管进行受精,获得2个原核期受精卵和1个桑椹胚。  相似文献   
设为首页 | 免责声明 | 关于勤云 | 加入收藏

Copyright©北京勤云科技发展有限公司  京ICP备09084417号