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981.
This study examined gender, socio-economic (SES), and ethnic group differences in academic performance (measured at 14 and 16 years) in a sample of 517 British pupils (mean age = 16.5 years). White pupils outperformed their Black and Pakistani counterparts and high SES pupils consistently outperformed their low SES counterparts. Results from two Multiple Indicators Multiple Causes (MIMIC) models showed that controlling for IQ variance minimizes these group differences. The MIMIC models also revealed that Pakistani pupils and girls tend to underperform academically relative to White pupils and boys, respectively, at 14 years, once IQ and SES have been partialed out. These and other, more specific, findings are discussed with reference to predictive test bias, selection and streaming procedures, and implications for educational policy. 相似文献
982.
It is shown in this paper that Homogeneous Two-variable Reactance Polyno- mials (HTRP's) can be expressed as a product of linear factors in the two-variables. Further, a Homogeneous Two-variable Reactance Function (HTRF) can be characterized in terms of the alteration property involving the coefficients of the linear factors of the HTRP in the numerator and denominator. Synthesis procedures for HTRF's are discus- sed; these realizations follow from the single variable RL- or RC-functions associated with a HTRF. Additional properties of HTRF, which will enable us to generate Two- variable Positive Real Functions and Two-variable Reactance Functions are also discussed. 相似文献
983.
The relevance feedback process uses information obtained from a user about a set of initially retrieved documents to improve subsequent search formulations and retrieval performance. In extended Boolean models, the relevance feedback implies not only that new query terms must be identified and re-weighted, but also that the terms must be connected with Boolean And/Or operators properly. Salton et al. proposed a relevance feedback method, called DNF (disjunctive normal form) method, for a well established extended Boolean model. However, this method mainly focuses on generating Boolean queries but does not concern about re-weighting query terms. Also, this method has some problems in generating reformulated Boolean queries. In this study, we investigate the problems of the DNF method and propose a relevance feedback method using hierarchical clustering techniques to solve those problems. We also propose a neural network model in which the term weights used in extended Boolean queries can be adjusted by the users’ relevance feedbacks. 相似文献
984.
Indumati V. Vidya S. Patil Rama Jailkhani 《Indian journal of clinical biochemistry : IJCB》2007,22(2):96-100
The awareness of osteoporosis has grown world wide in recent years. This silently progressing metabolic bone disease is widely
prevalent in India, and osteoporotic fractures are a common cause of morbidity and mortality in adult Indian men and women.
Rapid bone loss occurs in postmenopausal women due to hormonal factors which lead to increased risk of fractures. Biochemical
markers of bone metabolism are used to assess skeletal turnover. A cross-sectional study of 150 pre- and post menopausal women
was carried out at S.D.M College of Medical Sciences and Hospital, Dharwad, during the period of May 2005 to September 2005.
The study group consisted of 75 Premenopausal women in the age group of 25–45 years and 75 Postmenopausal women in the age
group of 46–65 years. Bone formation markers (Total Calcium, lonised calcium, Phosphorus, Alkaline phosphatase), and bone
resorption markers (Urinary Hydroxyproline) were analysed in pre and post menopausal women. Bone formation markers, Total
and lonised calcium were significantly decreased (p<0.001) and Alkaline phosphatase was significantly increased (p<0.001)
in postmenopausal women compared to premenopausal women. Bone resorption markers, Urinary hydroxyproline excretion was significantly
increased (p<0.001) in postmenopausal women. The results from this study suggest that simple, easy, common biochemical markers
can still be used to assess the bone turnover in postmenopausal women and hence their risk of developing osteoporosis and
fractures. 相似文献
985.
M. Smita K. Naidu A. N. Suryakar Sanjay C. Swami R. V. Katkam K. M. Kumbar 《Indian journal of clinical biochemistry : IJCB》2007,22(2):140-144
Cervical cancer (CaCx) is a global public health problem as it is the second most common cancer leading to the death of women
worldwide. Many references revealed that the low levels of antioxidants induce the generation of free radicals leading to
DNA damage and further mutations. In the present study attempt have been made to evaluate the levels of serum Lipid peroxide,
Nitric Oxide (NO.) Erythrocytic—Superoxide Dismutase (RBC-SOD), Vitamin-C, serum Copper (Cu) and serum Zinc (Zn). 120 patients were divided
in 4 groups according to the increasing CaCx stages i.e. stage I, II, III & IV respectively. All the patients were around
the age group of 25–65 years. 30 healthy women between the same age group were treated as controls. Highly significant increased
values of MDA, NO. and Cu were observed (p<0.001) whereas the activity of RBC-SOD, levels of Vitamin-C and Zn were significantly decreased in
CaCx patients as compared with healthy controls (p<0.001). Cu/Zn ratio was found to be altered in CaCx patients. From our
findings it can be concluded that the oxidative stress is induced among CaCx patients, which inturn increases the risk of
CaCx. 相似文献
986.
Alka Singh Sheila Uthappa V. Govindaraju T. Venkatesh 《Indian journal of clinical biochemistry : IJCB》2002,17(1):25-28
The present study conducted on twenty-five uncomplicated cases of acute myocardial infarction diagnosed by clinical and electrocardiographic
findings indicated significantly increased level of cardiac Troponin-T and increased activities of the enzymes total creatine
kinase, creatine kinase-MB, aspartate transaminase and lactate dehydrogenase as compared to the twenty-five healthy control
subjects. The level of cardiac Troponin-T and the activities of the enzymes total creatine kinase, creatine kinase-MB, aspartate
transaminase and lactate dehydrogenase was found to be higher in “Q” wave myocardial infarction patients as compared to the
non-“Q” wave and the controls. Since cardiac Troponin-T has been shown to increase in unstable angina and renal failure without
cardiac disease and creatine kinase-MB activity has been found to be normal in patients with unstable angina and increase
very slightly in patients with renal failure, it was concluded that a combination of cardiac Troponin-T and creatine kinase-MB
activity was sufficient for the early diagnosis of acute myocardial infarction. 相似文献
987.
Vasavidevi V. Bet Kishor H. Deshpande Adinath N. Suryakar Rajesh D. Ankush Raghavendra V. Katkam 《Indian journal of clinical biochemistry : IJCB》2006,21(2):177-180
Crystal aggregation and retention are critical events for the formation of kidney stones. There is a close association between
crystal development and free radical activity in vivo. In the present study 30 subjects presenting with urolithiasis were
included. Serum levels of total lipid peroxides, nitric oxide (as nitrite), α-tocopherol, plasma ascorbic acid (vitamin C)
and erythrocyte superoxide dismutase activity were measured. These findings were compared with 30 age matched control subjects
irrespective of sex. Student's ‘t’ test was applied for statistical analysis. There was a significant increase in lipid peroxides
(p<0.001), where as significant decrease in nitrite (p<0.01) and α-tocopherol (p<0.001) levels were observed. Plasma ascorbate
(p>0.05) and erythrocyte superoxide dismutase activity (p>0.05) was also found to be decreased but the difference was not
statistically significant which suggests that oxidative stress is evident in urolithiasis with depletion in antioxidant status
where as decrease in nitric oxide may be less abetting in disease condition. 相似文献
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