全文获取类型
收费全文 | 6812篇 |
免费 | 169篇 |
国内免费 | 73篇 |
专业分类
教育 | 3614篇 |
科学研究 | 999篇 |
各国文化 | 2篇 |
体育 | 1393篇 |
综合类 | 666篇 |
文化理论 | 2篇 |
信息传播 | 378篇 |
出版年
2024年 | 4篇 |
2023年 | 7篇 |
2022年 | 94篇 |
2021年 | 235篇 |
2020年 | 342篇 |
2019年 | 142篇 |
2018年 | 79篇 |
2017年 | 99篇 |
2016年 | 140篇 |
2015年 | 243篇 |
2014年 | 541篇 |
2013年 | 531篇 |
2012年 | 538篇 |
2011年 | 609篇 |
2010年 | 438篇 |
2009年 | 368篇 |
2008年 | 422篇 |
2007年 | 440篇 |
2006年 | 364篇 |
2005年 | 312篇 |
2004年 | 283篇 |
2003年 | 228篇 |
2002年 | 169篇 |
2001年 | 154篇 |
2000年 | 84篇 |
1999年 | 49篇 |
1998年 | 41篇 |
1997年 | 27篇 |
1996年 | 27篇 |
1995年 | 14篇 |
1994年 | 5篇 |
1993年 | 7篇 |
1992年 | 11篇 |
1991年 | 3篇 |
1989年 | 3篇 |
1957年 | 1篇 |
排序方式: 共有7054条查询结果,搜索用时 15 毫秒
71.
马振超 《广西职业技术学院学报》2019,(1):88-93
20世纪90年代以来,凭祥红木文化产业凭借独特的区位优势、成本优势、资源优势和后发优势,成为中国红木文化产业的后起之秀。但同时也面临着同质化趋势、发展规模受限、工艺水平滞后和全国性品牌缺失等困境。为此,应调整发展思路,从增强核心竞争力、加强精细化生产、提高工艺水平和打造国内知名品牌等方面创新发展路径,促进凭祥红木文化产业健康和可持续发展,为我国蓬勃兴起的红木文化产业提供有益的借鉴。 相似文献
72.
对企业核心体系的演变及客户关系管理存在模式———客户智能进行分析,可以避免企业在具体操作过程中的许多问题,增加企业的核心竞争力。 相似文献
73.
Ivan Cuk Dragan Mirkov Aleksandar Nedeljkovic Milos Kukolj Dusan Ugarkovic 《Sports biomechanics / International Society of Biomechanics in Sports》2016,15(2):207-219
The present study explored the method of testing muscle mechanical properties through the linear force–velocity (F–V) relationships obtained from loaded vertical jumps. Specifically, we hypothesised that the F–V relationship parameters depicting the force, power, and velocity of the tested muscles will differ among individuals of different physical fitness. Strength trained, physically active, and sedentary male participants (N = 10 + 10 + 10; age 20–29 years) were tested on maximum countermovement and squat jumps where manipulation of external loads provided a range of F and V data. The observed F–V relationships of the tested leg muscles were approximately linear and mainly strong (median correlation coefficients ranged from 0.77 to 0.92; all p < 0.05), independently of either the tested group or the jump type. The maximum power revealed higher values in the strength trained than in the physically active and sedentary participants. This difference originated from the differences in F-intercepts, rather than from the V-intercepts. We conclude that the observed parameters could be sensitive enough to detect the differences among both the individuals of different physical fitness and various jump types. The present findings support using loaded vertical jumps and, possibly, other maximum performance multi-joint movements for the assessment of mechanical properties of active muscles. 相似文献
74.
Eric T. Trexler Erica J. Roelofs Katie R. Hirsch Meredith G. Mock 《European Journal of Sport Science》2016,16(6):702-710
Caffeine and coffee are widely used among active individuals to enhance performance. The purpose of the current study was to compare the effects of acute coffee (COF) and caffeine anhydrous (CAF) intake on strength and sprint performance. Fifty-four resistance-trained males completed strength testing, consisting of one-rep max (1RM) and repetitions to fatigue (RTF) at 80% of 1RM for leg press (LP) and bench press (BP). Participants then completed five, 10-second cycle ergometer sprints separated by one minute of rest. Peak power (PP) and total work (TW) were recorded for each sprint. At least 48 hours later, participants returned and ingested a beverage containing CAF (300?mg flat dose; yielding 3–5?mg/kg bodyweight), COF (8.9?g; 303?mg caffeine), or placebo (PLA; 3.8?g non-caloric flavouring) 30 minutes before testing. LP 1RM was improved more by COF than CAF (p?=?.04), but not PLA (p?=?.99). Significant interactions were not observed for BP 1RM, BP RTF, or LP RTF (p?>?.05). There were no sprint?×?treatment interactions for PP or TW (p?>?.05). 95% confidence intervals revealed a significant improvement in sprint 1 TW for CAF, but not COF or PLA. For PLA, significant reductions were observed in sprint 4 PP, sprint 2 TW, sprint 4 TW, and average TW; significant reductions were not observed with CAF or COF. Neither COF nor CAF improved strength outcomes more than PLA, while both groups attenuated sprint power reductions to a similar degree. Coffee and caffeine anhydrous may be considered suitable pre-exercise caffeine sources for high-intensity exercise. 相似文献
75.
Objectives: Development of evidence-based methods of Paralympic classification requires research quantifying the relative strength of association between ratio-scaled measures of impairment and athletic performance. The purpose of this study was to quantify the extent to which muscle strength affects running performance in runners with and without brain impairment. Design: Cross-sectional study. Methods: Participants were 41 male runners: 13 with brain impairments (RBI) and 28 non-disabled (NDR). All participants completed a maximal 60-m sprint and a novel battery of three lower limb isometric strength tests. Results: RBI showed significantly lower strength scores compared with NDR on the more affected side in leg flexion (176 vs. 243?N), leg extension (993 vs. 1661?N) and plantarflexion (824 vs. 1457?N). Significant differences were also seen on the less affected side in plantarflexion (1072 vs. 1508?N). RBI were significantly slower in the acceleration phase (0–15?m) (3.2?s?±?0.3?vs. 2.8?s?±?0.2) and top speed phase (30?60?m) (4.3?s?±?0.6?vs. 3.8?s?±?0.3). Correlation analysis showed stronger relationships between strength and running performance in RBI than NDR; however, the correlations were not significant. Conclusions: This study evaluated measures to assess strength for the purposes of classification and found that the measures were significantly different in RBI compared with NDR indicating the tests were able to capture strength impairment in this population. This study indicates that strength may be an important impairment type to assess in this population, as impairments of muscle strength may influence the outcome of running performance in athletes with more severe impairments. 相似文献
76.
Lee Ingle Ashlie Stephenson Gavin R. Sandercock 《European Journal of Sport Science》2016,16(8):1187-1196
The aim of the study was to compare and contrast habitual physical activity (PA) profiles and muscular fitness in schoolchildren from northern and southern regions of England. Data were collected from two secondary schools in the north east (NE) of England. The study procedures followed methods employed by the East of England Healthy Hearts Study in 10–16-year-old boys and girls based in the south east (SE) region of England and data were compared. Habitual physical activity (PAQ-A), vertical jump test, and hand-grip (HG) strength were assessed. We converted raw scores from all assessments to age- and sex-normalised z-scores. We recruited 597 children (58% boys) in the NE and compared findings to 597 age- and sex-matched boys and girls from the SE. Boys in the SE had significantly stronger HG scores, jumped higher, were more powerful (mean peak power: 2131?W vs. 1782?W; P?0.0001), and reported being more physically active (mean PAQ-A: 2.9 vs. 2.5; P?0.0001) than their male counterparts in the NE. In girls, the opposite trend was evident. Girls from the NE of England had a higher HG score, jumped higher, and were more powerful (mean peak power: 2114?W vs. 1839?W; P?.0001) than their peers from the SE. Regional variations in the habitual PA profiles and muscular fitness of schoolchildren from the SE and NE of England do exist. The systematic surveillance of children’s PA and fitness profiles throughout England would help identify regional inequalities on a larger scale. 相似文献
77.
Toshiaki Miyamoto Hiroyuki Kamada Akira Tamaki Toshio Moritani 《European Journal of Sport Science》2016,16(8):1104-1110
The aim of this study was to investigate the effect of low-intensity exercise training using belt electrode skeletal muscle electrical stimulation on muscle strength and cardiorespiratory fitness in healthy subjects. Nineteen healthy subjects were allocated into control or intervention groups; in both groups the participants kept regular physical activity while the intervention group underwent 30 min B-SES training at 3–4 METs for four weeks. Knee extensor muscle strength and cardiorespiratory endurance during incremental exercise test were measured at baseline and after four weeks for all participants. The relative change of knee extensor muscle strength in the intervention group was significantly higher than control group (p?.05). Also, oxygen uptake at ventilator threshold and peak oxygen uptake during incremental exercise test significantly increased in the intervention group when compared with control group (p?.05). This study showed that prolonged low-intensity B-SES training resulted in significant increases in muscle strength and cardiorespiratory fitness in healthy subjects. Our present work suggested that B-SES training could assist patients who might have difficulty performing adequate voluntary exercise because of excessive obesity, orthopaedic problems and chronic diseases such as cardiovascular disease and type 2 diabetes. An intervention study conducted for such patients is strongly recommended. 相似文献
78.
魏瑞演 《福建工程学院学报》2002,(1)
从基本的钢结构材料在高温下的力学性能着手 ,进行高温条件下钢结构材料的性能试验 ,建立高温下钢材的屈服强度、极限强度、弹性模量和极限应变随温度变化的力学模型 ,为高温 (火灾 )条件下钢结构的结构分析提供依据。 相似文献
79.
吕景泉 《天津职业院校联合学报》2006,8(1):5-12
结合全国职业教育工作会议精神,回顾天津职业教育发展的历程,指明中德职业技术学院在落实以就业为导向,加强专业建设;以能力为本位,加强课程体系和教材建设;以技能为中心,加强实训基地和师资队伍建设;以职业道德为核心,加强学生思想政治工作中的实践的重要性。 相似文献
80.
谈企业核心竞争力的管理 总被引:1,自引:0,他引:1
企业核心竞争力是企业获取竞争优势的来源和基础,加强对企业核心竞争力的管理并不断提升企业核心竞争力,就能使企业长期保持自己的优势。 相似文献