全文获取类型
收费全文 | 548篇 |
免费 | 8篇 |
国内免费 | 2篇 |
专业分类
教育 | 383篇 |
科学研究 | 73篇 |
各国文化 | 2篇 |
体育 | 36篇 |
综合类 | 1篇 |
文化理论 | 6篇 |
信息传播 | 57篇 |
出版年
2022年 | 6篇 |
2021年 | 6篇 |
2020年 | 14篇 |
2019年 | 15篇 |
2018年 | 21篇 |
2017年 | 22篇 |
2016年 | 22篇 |
2015年 | 11篇 |
2014年 | 21篇 |
2013年 | 90篇 |
2012年 | 7篇 |
2011年 | 16篇 |
2010年 | 8篇 |
2009年 | 7篇 |
2008年 | 9篇 |
2007年 | 7篇 |
2006年 | 7篇 |
2005年 | 8篇 |
2004年 | 10篇 |
2003年 | 9篇 |
2002年 | 8篇 |
2001年 | 12篇 |
2000年 | 6篇 |
1999年 | 9篇 |
1998年 | 8篇 |
1996年 | 8篇 |
1994年 | 8篇 |
1993年 | 4篇 |
1992年 | 10篇 |
1991年 | 7篇 |
1990年 | 8篇 |
1989年 | 10篇 |
1988年 | 7篇 |
1987年 | 4篇 |
1986年 | 9篇 |
1985年 | 10篇 |
1984年 | 7篇 |
1983年 | 8篇 |
1980年 | 8篇 |
1978年 | 14篇 |
1976年 | 8篇 |
1974年 | 8篇 |
1973年 | 4篇 |
1972年 | 4篇 |
1969年 | 4篇 |
1968年 | 3篇 |
1967年 | 3篇 |
1965年 | 4篇 |
1961年 | 3篇 |
1947年 | 3篇 |
排序方式: 共有558条查询结果,搜索用时 15 毫秒
91.
92.
M. Shafi M. Zargar Z. A. Shah M. Salahuddin M. Siddiqi 《Indian journal of clinical biochemistry : IJCB》1998,13(2):106-110
Serum and urine samples from 513 patients clinically suspected of monoclonal gammopathies over a period of five years (1992–97)
were subjected to various immunological procedures viz, electrophoresis, immunoelectrophoresis and immunoglobulin estimations.
Laboratory investigations confirmed gammopathies in 10.33%. It was observed that overall age of incidence for monoclonal gammopathies
in both sexes was between 42–72 years with a male to female ratio of 1.4∶1. Predominant paraprotein detected was IgG type
(75.47%) followed by IgA (16.98%) and Bence Jones proteins (7.55%). Amongst positive patients, 64.16% were having kappa (k) type light chains and 35.84% lambda (δ) type light chains. 69.39% patients with serum M component (IgG and IgA) had Bence
Jones proteinuria. Densitometric scanning revealed that majority of IgG type paraprotein was found in the slow gamma globulin
region and majority of IgA type paraprotein was found equally distributed between beta and fast gamma globulin regions. Both
types had decreased albumin and alpha-2-globulin concentrations as compared to normal controls. Immunoglobulin levels in patients
with paraprotein had very high levels of serum IgG (6467.0 mg%) and IgA (2714.0 mg%) in respective types of monoclonal gammopathies;
the rest of immunoglobulin classes were either at normal or decreased levels. 相似文献
93.
The educational and developmental needs of children with disabilities in general, and of children with vision impairments in particular, have been ignored until recently in the Sultanate of Oman. However, the situation of special education and rehabilitation services is changing and there is progress to report. This article presents an overview of the prevalence and patterns of vision impairment, types of services offered, and priorities for future work. 相似文献
94.
D. VEKSTEIN A. MEHREZ Z. LASLO A. SOLOMON 《European Journal of Engineering Education》1999,24(1):95-104
This paper focuses on the current situation of engineering education in Israel, the debate over the ways to manage it, and the prospects that a balanced education policy can entail for socio-economic development. Two degrees in engineering, the BTech and BSc, are described. It transpired that the BTech failed to meet the expectations. From the on-going debate about the situation, the need for a balanced policy for engineering education has emerged. This policy is outlined and it is shown that it can not only improve the BTech situation, but also Israel's national innovation system by viewing ‘research’ and ‘applied’ engineers as complementary to, rather than competing with, each other. It is also suggested that this balanced policy should implement project-based instruction in the engineering curriculum, both in the BTech and BSc programmes. 相似文献
95.
Sarant JZ Holt CM Dowell RC Rickards FW Blamey PJ 《Journal of deaf studies and deaf education》2009,14(2):205-217
This article documented spoken language outcomes for preschool children with hearing loss and examined the relationships between language abilities and characteristics of children such as degree of hearing loss, cognitive abilities, age at entry to early intervention, and parent involvement in children's intervention programs. Participants were evaluated using a combination of the Child Development Inventory, the Peabody Picture Vocabulary Test, and the Preschool Clinical Evaluation of Language Fundamentals depending on their age at the time of assessment. Maternal education, cognitive ability, and family involvement were also measured. Over half of the children who participated in this study had poor language outcomes overall. No significant differences were found in language outcomes on any of the measures for children who were diagnosed early and those diagnosed later. Multiple regression analyses showed that family participation, degree of hearing loss, and cognitive ability significantly predicted language outcomes and together accounted for almost 60% of the variance in scores. This article highlights the importance of family participation in intervention programs to enable children to achieve optimal language outcomes. Further work may clarify the effects of early diagnosis on language outcomes for preschool children. 相似文献
96.
97.
Anna Bezulska M. Naczk Z. Adach J. Arlet J. Celichowski 《Journal of sports sciences》2018,36(5):565-570
Numerous motor abilities depend on the activity of proprioceptors, which has been suggested to be genetically determined. To test this hypothesis, the control of torque generated by knee extensors and knee position was studied in 30 father–son pairs both before and immediately after running. After stabilisation of the participant in a sitting position, the knee joint of his dominant leg was flexed to 90°, and the maximal voluntary torque (MVT) of the dominant knee extensors under static conditions was measured. The participant then tried five times to produce 50% of the MVT. Next, the participant extended the knee to 45° five times without visual control. Significant correlations between the reproducibility of successive trials for groups of fathers and their sons were found. The correlation coefficients for the repeatability of the knee extension torque were 0.69 (confidence interval [CI] = 0.45–0.84; P < 0.01) and 0.75 (CI = 0.54–0.87; P < 0.01) before and after the fatiguing exercise, respectively, whereas the coefficient for the reproducibility of positioning the knee was 0.49 (CI = 0.16–0.72; P < 0.01) after the fatiguing exercise. Our results indicate a significant influence of hereditary factors on the control of limb torque and position. 相似文献
98.
Despite being invasive within surrounding brain tissues and the central nervous system, little is known about the mechanical properties of brain tumor cells in comparison with benign cells. Here, we present the first measurements of the peak pressure drop due to the passage of benign and cancerous brain cells through confined microchannels in a “microfluidic cell squeezer” device, as well as the elongation, speed, and entry time of the cells in confined channels. We find that cancerous and benign brain cells cannot be differentiated based on speeds or elongation. We have found that the entry time into a narrow constriction is a more sensitive indicator of the differences between malignant and healthy glial cells than pressure drops. Importantly, we also find that brain tumor cells take a longer time to squeeze through a constriction and migrate more slowly than benign cells in two dimensional wound healing assays. Based on these observations, we arrive at the surprising conclusion that the prevailing notion of extraneural cancer cells being more mechanically compliant than benign cells may not apply to brain cancer cells. 相似文献
99.
100.
Z S Masangkay K A McCluskey C W McIntyre J Sims-Knight B E Vaughn J H Flavell 《Child development》1974,45(2):357-366