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961.
刘丞 《安阳师范学院学报》2010,(4):69-72
表达空间位移事件,不同的语言(方言)可以用不同的表示手段。安阳虽然位于北方,然而空间表达与普通话却有很大不同。文章主要从方所题元的类型、方所题元的标注位置、方所介词的类型等方面进行考察,同时也涉及到安阳方言中介词"在"、"到"与不同动词的组合所呈现出的与普通话甚至北京口语的不同。 相似文献
962.
本论文提出了在地面采用气动方式模拟空间微重力环境下实验系统方案,该实验系统用于验证空间机器人的捕获性能。本验证系统由模拟目标星实验模型、气浮平台、双目视觉系统、通讯系统、电机系统,传感器系统、信号调理系统六个子系统组成。本论文首先阐述了系统各个子系统的设计方案,其次讨论了基于层次递减式控制系统结构,最后重点研究了模拟目标星在垂直地面方向上的漂浮运动控制算法,仿真和实验结果验证了该控制算法是有效的。 相似文献
963.
We investigated changes in activity and recovery cycles and skill involvements: (1) during National Rugby league (NRL) match-play from 2004 to 2014 and (2) among successful and unsuccessful teams over the same period. Teams were divided into 4 tiers according to final ladder position: (A) 1st–4th, (B) 5th–8th, (C) 9th–12th and (D) 13th–16th. Total, mean and maximum ball-in-play time decreased, while recovery time increased from 2004 to 2014. Offensive and defensive skill involvements changed differentially over time with moderate to large reductions in the number of play-the-balls, offloads and missed tackles, and moderate to large increases in the number of passes, tackles made and ineffective tackles. The gap between Tier A and Tier D decreased for mean activity time and the proportion of short (<45 s) ball-in-play periods. Conversely, the gap between Tier A and Tier D increased for skill involvements, with Tier A completing more play-the-balls, and Tier D performing a greater number of offloads, and total, missed and ineffective tackles. Our results demonstrate the decreasing ball-in-play demands of NRL competition over 11 seasons. However, our data also highlight the narrowing gap in ball-in-play demands, and increasing gap in skill involvements between the top tier and bottom tier teams. 相似文献
964.
João Paulo Lopes-Silva Jonatas Ferreira Da Silva Santos Guilherme Giannini Artioli Irineu Loturco Chris Abbiss Emerson Franchini 《European Journal of Sport Science》2018,18(3):431-440
Purpose: To investigate the effect of sodium bicarbonate (NaHCO3) on performance and estimated energy system contribution during simulated taekwondo combat. Methods: Nine taekwondo athletes completed two experimental sessions separated by at least 48?h. Athletes consumed 300?mg/kg body mass of NaHCO3 or placebo (CaCO3) 90?min before the combat simulation (three rounds of 2 min separated by 1 min passive recovery), in a double-blind, randomized, repeated-measures crossover design. All simulated combat was filmed to quantify the time spent fighting in each round. Lactate concentration [La?] and rating of perceived exertion (RPE) were measured before and after each round, whereas heart rate (HR) and the estimated contribution of the oxidative (WOXI), ATP (adenosine triphosphate)-phosphocreatine (PCr) (WPCR), and glycolytic (W[ La? ]) systems were calculated during the combat simulation. Results: [La?] increased significantly after NaHCO3 ingestion, when compared with the placebo condition (+14%, P?=?0.04, d?=?3.70). NaHCO3 ingestion resulted in greater estimated glycolytic energy contribution in the first round when compared with the placebo condition (+31%, P?=?0.01, d?=?3.48). Total attack time was significantly greater after NaHCO3 when compared with placebo (+13%, P?=?0.05, d?=?1.15). WOXI, WPCR, VO2, HR and RPE were not different between conditions (P?>?0.05). Conclusion: NaHCO3 ingestion was able to increase the contribution of glycolytic metabolism and, therefore, improve performance during simulated taekwondo combat. 相似文献
965.
基于易逝性高科技产品的价值易逝性与高新技术特性,构建基于随机微分方程的易逝性高科技产品更新时机模型以解决易逝性高科技产品更新时机不确定性问题。首先,利用威布尔分布和多项式逼近函数构造无技术进步与价值易逝等外部因素干扰的易逝性高科技产品使用寿命模型;其次,采用布朗运动来模拟外部因素对易逝性高科技产品更新时机的影响情况,进而建立技术进步和价值易逝影响下易逝性高科技产品更新时机波动率模型;最后,选取i Pad作为易逝性高科技产品案例验证所构建的易逝性高科技产品更新时机模型,研究结果表明该模型具有较强的稳健性,可为高新技术生产企业在产品更新换代时提供一定的参考。 相似文献
966.