全文获取类型
收费全文 | 514篇 |
免费 | 14篇 |
国内免费 | 1篇 |
专业分类
教育 | 319篇 |
科学研究 | 129篇 |
各国文化 | 4篇 |
体育 | 29篇 |
综合类 | 4篇 |
文化理论 | 5篇 |
信息传播 | 39篇 |
出版年
2023年 | 9篇 |
2022年 | 10篇 |
2021年 | 22篇 |
2020年 | 11篇 |
2019年 | 30篇 |
2018年 | 30篇 |
2017年 | 43篇 |
2016年 | 23篇 |
2015年 | 22篇 |
2014年 | 33篇 |
2013年 | 63篇 |
2012年 | 37篇 |
2011年 | 20篇 |
2010年 | 26篇 |
2009年 | 22篇 |
2008年 | 25篇 |
2007年 | 14篇 |
2006年 | 9篇 |
2005年 | 11篇 |
2004年 | 10篇 |
2003年 | 9篇 |
2002年 | 11篇 |
2001年 | 6篇 |
2000年 | 7篇 |
1999年 | 1篇 |
1997年 | 1篇 |
1996年 | 2篇 |
1995年 | 1篇 |
1993年 | 2篇 |
1992年 | 2篇 |
1991年 | 3篇 |
1990年 | 2篇 |
1989年 | 2篇 |
1988年 | 1篇 |
1987年 | 1篇 |
1985年 | 1篇 |
1984年 | 1篇 |
1980年 | 1篇 |
1978年 | 1篇 |
1976年 | 1篇 |
1975年 | 1篇 |
1970年 | 1篇 |
1967年 | 1篇 |
排序方式: 共有529条查询结果,搜索用时 10 毫秒
141.
Muhammad Ali Asadullah Sumaira Mirza Muhammad Zia Ul Haq Tahir Yaqoob Sajid Hussain 《Higher Education Quarterly》2023,77(1):102-120
Fresh PhD recipients are experiencing restricted career opportunities yet the enrolment of PhD Scholars is increasing rapidly. Perhaps, doctoral students lack conscious educational decision-making. Building on such a perspective of doctoral students' unconscious educational choices, we explored their educational choices throughout their life trajectory. We started with a qualitative inquiry of 18 different PhD scholars in Pakistan. The findings helped us in developing a measure to determine the extent of herding in doctoral students' educational decisions. We ‘benefitted from’ this opportunity and validated the scale in two separate quantitative inquiries for conducting an exploratory factor analysis and confirmatory factor analysis. The study concluded a 3-dimensional scale (consisting of 15-items) for measuring ‘herding in educational decisions’. The study offers certain implications for conscious educational decisions. 相似文献
142.
The focus of this paper is on the design of a H∞ decentralized observation and control approach for a class of nonlinear disturbed interconnected systems. The proposed scheme is formulated as an optimization problem in terms of linear matrix inequality (LMI) to compute the robust observation and control gain matrices simultaneously, to maximize the bounds on the nonlinearity which the system can tolerate without going unstable, to improve the performance of the proposed control strategy by minimizing the H∞ criterion and to ensure the stability of the closed loop system in the Lyapunov framework despite the exogenous disturbances applied to the subsystems. A simulation is provided on a 3-machine power system, which generators are strongly nonlinear interconnected, to show the efficiency of the designed approach. 相似文献
143.
Maryam Farahnak Zarabi Ali Farhangi Samaneh Khademi Mazdeh Zahra Ansarian Davod Zare Mohammad Reza Mehrabi Azim Akbarzadeh 《Indian journal of clinical biochemistry : IJCB》2014,29(2):154-160
Carboxylate-modified gold nanoparticles (GNPs) were synthesized in a simple one-step process based on the reduction of tetrachloroauric acid by aspartic acid in water. GNPs were identified by UV–Vis spectroscopy, dynamic light scattering (DLS) and transmission electron microscopy. Conjugation of protein molecules with functionalized nanoparticles was performed through electrostatic interaction. The GNP–protein conjugates were characterized by gel electrophoresis. The interaction between functionalized GNPs and protein molecules lead to conformational transition of protein structure after conjugation of protein with GNPs. This process was investigated by fluorescence spectroscopy and circular dichroism spectroscopy. 相似文献
144.
Ali Farhangi Dariush Norouzian Mohammad Reza Mehrabi Mohsen Chiani Zahra Saffari Maryam Farahnak Azim Akbarzadeh 《Indian journal of clinical biochemistry : IJCB》2014,29(4):406-417
The objective of this study is to induce experimental diabetes mellitus by streptozotocin in normal adult Wistar rats via comparison of changes in body weight, consumption of food, volume of water, urine and levels of glucose, insulin and C-peptide in serum, between normal and diabetic rats. Intra-venous injection of 60 mg/kg dose of streptozotocin in 250–300 g (75–90 days) adult Wistar rats makes pancreas swell and causes degeneration in Langerhans islet β-cells and induces experimental diabetes mellitus in 2–4 days. For a microscopic study of degeneration of Langerhans islet β-cells of diabetic rats, biopsy from pancreas tissue of diabetic and normal rats, staining and comparison between them, were done. In this process, after collagenase digestion of pancreas, islets were isolated, dissociated and identified by dithizone method and then with enzymatic procedure by DNase and trypsin, the islet cells changed into single cells and β-cells were identified by immune fluorescence method and then assayed by flow-cytometer. Donor tissue in each step of work was prepared from 38 adult male Wistar rats weighted 250–300 g (75–90 days). Transplantation was performed in rats after 2–4 weeks of diabetes induction. In this study, the levels of insulin, C-peptide and glucose in diabetic rats reached to normal range as compared to un-diabetic rats in 20 days after transplantation of islet cells. Transplantation was performed under the cortex of testis as immunoisolated place for islet cells transplantation. 相似文献
145.
Inter-organizational knowledge sharing systems (IOKSS) can serve as strategic systems for knowledge-based sectors. Most prior research on inter-organizational systems (IOSs) focuses on organizations’ adoption of such systems; they reveal little about knowledge workers’ adoption of IOS, especially in horizontally linked firms. Knowledge workers’ perception is critical to the deployment of IOKSS at all stages. On the basis of a Delphi technique in the health sector, this study demonstrates that IOKSS can benefit individuals, customers, organizations, the sector, and the knowledge sharing process, and that the challenges of IOKSS arise from individuals, peers, IOKSS, organizations, and the sector. 相似文献
146.
Seidi A Kaji H Annabi N Ostrovidov S Ramalingam M Khademhosseini A 《Biomicrofluidics》2011,5(2):22214
In this study, we developed a miniaturized microfluidic-based high-throughput cell toxicity assay to create an in vitro model of Parkinson's disease (PD). In particular, we generated concentration gradients of 6-hydroxydopamine (6-OHDA) to trigger a process of neuronal apoptosis in pheochromocytoma PC12 neuronal cell line. PC12 cells were cultured in a microfluidic channel, and a concentration gradient of 6-OHDA was generated in the channel by using a back and forth movement of the fluid flow. Cellular apoptosis was then analyzed along the channel. The results indicate that at low concentrations of 6-OHDA along the gradient (i.e., approximately less than 260 μM), the neuronal death in the channel was mainly induced by apoptosis, while at higher concentrations, 6-OHDA induced neuronal death mainly through necrosis. Thus, this concentration appears to be useful for creating an in vitro model of PD by inducing the highest level of apoptosis in PC12 cells. As microfluidic systems are advantageous in a range of properties such as throughput and lower use of reagents, they may provide a useful approach for generating in vitro models of disease for drug discovery applications. 相似文献
147.
148.
比较和对照两位伟大的思想家——孔子与鲁米在家庭自然观、道德观、生态观等方面内在的相似性与不同点,可以丰富和拓宽我们对自然和自身的认知,建立针对生态破坏和过度消费自然的道德意识的基础.更重要的是,他们的智慧为我们构造了不同文化和文明之间理解和沟通的桥梁. 相似文献
149.
Halim Eshrat M. Ali Hussain Kaiser Jamil Mala Rao 《Indian journal of clinical biochemistry : IJCB》2001,16(1):77-80
The hypoglycemic effect of the aqueous extract ofAbroma augusta (Family: Steculiceae) was studied in normal as well as alloxan diabetic rats. Treatement of diabetic rats with 4 ml (4gm
dry weight) of agueous extract ofA. augusta for 16 weeks resulted in gradual but significant fall in fasting blood glucose and improvement in glucose tolerance. Serum
total and LDL cholesterol and triacylglycerol which increased in diabetic rats showed improvement. These results show that
the water extract ofA. augusta has both hypoglycemic and hypocholesterolemic effects. 相似文献
150.
Küme T Sişman AR Solak A Tuğlu B Cinkooğlu B Coker C 《Biochemia medica : ?asopis Hrvatskoga dru?tva medicinskih biokemi?ara / HDMB》2012,22(2):189-201