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151.
The present comparative study investigates the perceptions of male and female teachers regarding the relationship between empowerment and job satisfaction. The study aims to look at factors that empower teachers and lead to job satisfaction from teachers’ perspectives. For that purpose, teachers were selected from three educational levels (primary, middle and secondary) in Al-Farwaniya District in the State of Kuwait. A total of 231 teachers from the Al-Farwaniya School District responded to a questionnaire. Both t-test and one-way ANOVA were applied. Data analysis reveals a lack of job empowerment and a high degree of dissatisfaction among teachers. The study concludes with several suggestions including opening up a dialogue with teachers in order to understand their problems and needs and involving them in the process of decision-making and change. 相似文献
152.
Diana Nakidde Phillip Zellner Mohammad Mehdi Alemi Tyler Shake Yahya Hosseini Maria V. Riquelme Amy Pruden Masoud Agah 《Biomicrofluidics》2015,9(1)
In this study, a 3D passivated-electrode, insulator-based dielectrophoresis microchip (3D πDEP) is presented. This technology combines the benefits of electrode-based DEP, insulator-based DEP, and three dimensional insulating features with the goal of improving trapping efficiency of biological species at low applied signals and fostering wide frequency range operation of the microfluidic device. The 3D πDEP chips were fabricated by making 3D structures in silicon using reactive ion etching. The reusable electrodes are deposited on second glass substrate and then aligned to the microfluidic channel to capacitively couple the electric signal through a 100 μm glass slide. The 3D insulating structures generate high electric field gradients, which ultimately increases the DEP force. To demonstrate the capabilities of 3D πDEP, Staphylococcus aureus was trapped from water samples under varied electrical environments. Trapping efficiencies of 100% were obtained at flow rates as high as 350 μl/h and 70% at flow rates as high as 750 μl/h. Additionally, for live bacteria samples, 100% trapping was demonstrated over a wide frequency range from 50 to 400 kHz with an amplitude applied signal of 200 Vpp. 20% trapping of bacteria was observed at applied voltages as low as 50 Vpp. We demonstrate selective trapping of live and dead bacteria at frequencies ranging from 30 to 60 kHz at 400 Vpp with over 90% of the live bacteria trapped while most of the dead bacteria escape. 相似文献
153.
Ali Afaghi Sehraneh Ghaemi Amir Rikhtehgar Ghiasi Mohammad Ali Badamchizadeh 《Journal of The Franklin Institute》2021,358(8):4326-4347
This paper considers a class of nonlinear fractional-order multi-agent systems (FOMASs) with time-varying delay and unknown dynamics, and a new robust adaptive control technique is proposed for cooperative control. The unknown nonlinearities of the systems are online approximated by the introduced recurrent general type-2 fuzzy neural network (RGT2FNN). The unknown nonlinear functions are estimated, simultaneously with the control process. In other words, at each sample time the parameters of the proposed RGT2FNNs are updated and then the control signals are generated. In addition to the unknown dynamics, the orders of the fractional systems are also supposed to be unknown. The biogeography-based optimization algorithm (BBO) is extended to estimate the unknown parameters of RGT2FNN and fractional-orders. A LMI based compensator is introduced to guarantee the robustness of the proposed control system. The excellent performance and effectiveness of the suggested method is verified by several simulation examples and it is compared with the other methods. It is confirmed that the introduced cooperative controller results in a desirable performance in the presence of time-varying delay, unknown dynamics, and unknown fractional-orders. 相似文献
154.
155.
Yasir Hasan Siddique Tanveer Beg Mohammad Afzal 《Indian journal of clinical biochemistry : IJCB》2009,24(3):294-300
Hydrogen peroxide is one of the reactive oxygen species for cellular injury. It is overproduced during oxidative stress and
is known to damage proteins, nucleic acids and cell membranes. The present study was aimed to study the protective effect
of ascorbic acid against the toxic doses of hydrogen peroxide using lipid peroxidation and cytokinesis blocked micronucleus
assay. Hydrogen peroxide was studied at 50, 100 and 200μM and was found to increase a dose dependent increase in lipid peroxidation
and micronuclei frequency. The treatment of 100 and 200μM of hydrogen peroxide separately along with 20, 40 and 80μM of ascorbic
acid showed a dose dependent decrease in the lipid peroxidation and micronuclei frequency. The results suggest a protective
effect of ascorbic acid against the hydrogen peroxide induced oxidative damage in cultured human peripheral blood lymphocytes. 相似文献
156.
University mathematics is often presented in a formal way that causes many students to cope by memorising what they perceive
as a fixed body of knowledge rather than learning to think for themselves. This research studies the effects on students'
attitudes of a course encouraging co-operative problem-solving and reflection on the thinking activities involved. The attitudinal
questionnaire was shown to the students' teachers who were asked to specify the attitudes they expect from their students
and the attitudes they prefer. This was used to give a ‘desired direction of change’ from expected to preferred. Before the
course, half the students responded that university mathematics did not make sense. A majority declared negative attitudes
such as anxiety, fear of new problems and lack of confidence. During the problem-solving course the changes were almost all
in the desired direction. During the following six months of standard mathematics lecturing, almost all changes were in the
opposite direction.
This revised version was published online in July 2006 with corrections to the Cover Date. 相似文献
157.
This article is a product of in‐depth research in Yaffa, The Arab Democratic School that was carried out in 2004/05, as part of a study on alternative Arab education in Israel. Its aim, beyond telling the story of Yaffa, is to explicate the motivations that underlay this initiative, and to examine parental choice amongst the disadvantaged. We ask how the Arabs’ parental choice is affected by their (marginalised) social location, by how far they are from the dominant culture, and by their (in)capacity to make a difference. Apparently, to make a choice is a multidimensional act, reflecting the Palestinian citizens’ resistance to their marginalisation and unwillingness to be subjugated through non‐democratic educational perceptions. Their positionality resonates in Yaffa, as an act of intervention, and their search for an alternative reality where democratic education is not and cannot be separated from the Palestinian citizens’ need to imagine themselves as Arabs. 相似文献
158.
Recent studies show that reduction in cross-sectional area can be used to improve the concentration factor in microscale bioseparations. Due to simplicity in fabrication process, a step reduction in cross-sectional area is generally implemented in microchip to increase the concentration factor. But the sudden change in cross-sectional area can introduce significant band dispersion and distortion. This paper reports a new fabrication technique to form a gradual reduction in cross-sectional area in polymethylmethacrylate (PMMA) microchannel for both anionic and cationic isotachophoresis (ITP). The fabrication technique is based on hot embossing and surface modification assisted bonding method. Both one-dimensional and two-dimensional gradual reduction in cross-sectional area microchannels were formed on PMMA with high fidelity using proposed techniques. ITP experiments were conducted to separate and preconcentrate fluorescent proteins in these microchips. Thousand fold and ten thousand fold increase in concentrations were obtained when 10 × and 100 × gradual reduction in cross-sectional area microchannels were used for ITP. 相似文献
159.
The performance of complementary feeders, running in parallel, can be significantly improved by installing static transfer switches (STSs) at critical locations. We develop the STS control logic, which transfers the critical load from the preferred feeder to the alternate feeder when a voltage sag or a fault occurs on the preferred feeder. A forced commutation technique is proposed and implemented to turn off the preferred feeders' thyristor, thus avoiding cross current to flow and minimizing the transfer time. Simulation results show that the forced commutation technique is more effective as compared to the recently proposed time delay technique for STS operation. Two different feeders, namely New Exchange, the preferred feeder, and Sector 1-10/2, the alternate feeder of Islamabad Electric Supply COmpany (IESCO), Pakistan, have been selected for case studies. The software PSCAD/EMTDC professional package has been used for simulation. 相似文献
160.
Mohammad Alauddin Asaduzzaman Khan 《Educational Assessment, Evaluation and Accountability》2010,22(4):293-305
This paper investigates whether performance in progressive assessment necessarily influences the outcome in the end-of-semester
final examination using the experience of an introductory postgraduate statistics course at a large Australian university.
The average score on progressive assessments was higher than that of the final examination. Students attaining a higher distinction
(HD) at the progressive assessment had a 37% chance of securing the same grade in the final examination, while students securing
just a pass grade at the progressive assessment had 54 percent chance of failure in the final examination. Multiple regression
analysis revealed that students’ performance in progressive assessments had a significant positive impact on final examination,
so has the impact of learning diary. Mid-semester tests based exclusively on multiple choice questions (MCQs), more weights
in progressive assessment and class-size appeared to have significant negative impact on the performance in the final examination.
Focus group discussions suggest that (a) the final examination under timed conditions; (b) competing demands on time for final
examination in other courses due contemporaneously; and (c) weaker motivation to sustain the momentum due to pass or near
pass based on progressive assessments were the main hurdles in achieving better performance in the final examination. 相似文献