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21.
School governing bodies in England have considerable powers and duties, and their formal role positions them as decision-makers. This article draws on qualitative research in the governing bodies of four maintained schools. Using deliberative democracy as a sensitising concept, the article considers some processes by which decisions are made (or not made) in governing bodies. Without claiming that governors never make decisions, it explores constraints and limitations on their ability to do so. Governors exhibit a paradoxical combination of busy-ness and passivity. On the one hand, governing bodies are constituted and structured around activity and technically decisions were made. On the other, decisions could rarely be attributed to active choices by governors. Rather, their more passive agreement with actions and positions was presented as almost unavoidable ‘common sense’, either due to the national policy context or the headteacher’s presentation of the available options.  相似文献   
22.
What do students stand to gain from high-stakes, standardized testing? We consider answers to this question from the perspective of urban district leaders tasked with designing and overseeing the implementation of standardized testing policies. Results revealed variation in leaders’ framing of and rationale for standardized testing with respect to benefits for students and whether/why students should strive for high test scores. Implications for both approaches to standardized testing and broader improvement initiatives are discussed.  相似文献   
23.
根据中医内科辩证和因时制宜原则 ,对校田径代表队在夏季比赛期间服用活血皇浆前后进行血液动力流变学和血液有形成分参数的比较观察结果表明 ,运动员服液后在脉率 (PR)、每搏量 (SV)、心输出量 (CO)、左心有效泵力 (VPE)和左心能量有效利用率 (EWK )改善的同时 ,出现心肌耗氧量 (HOV)、心肌耗氧指数 (HOI)、心肌血液需要量 (CMBN)、心肌血液灌注量(CMBV)和总周阻 (TPR)、标准周阻 (SPR)、收缩压 (SP)舒张压 (DP)等参数下降 ,呈现机能和能量节省化 ,而血液状态则表现为血容量 (BV)增多 ,全血粘度 (η)和还原血粘度 (ηr)下降 ,切变应力增高 ,血流速度加快 ,有利于维持微循环正常功能。血液有形成分的改变提示 ,血红蛋白 (Hb)红细胞比积 (HCT)和血小板 (PL T)有增高趋势 ;平均红细胞血红蛋白浓度 (MCHC)下降 ,则有可能与 BV相对增多 ,红细胞 (RBC)体积增大有关  相似文献   
24.
In typical development, gestures precede and predict language development. This study examines the developmental sequence of expressive communication and relations between specific gestural and language milestones in toddlers with autism spectrum disorder (ASD), who demonstrate marked difficulty with gesture production and language. Communication skills across five stages (gestures, word approximations, first words, gesture-word combinations, and two-word combinations) were assessed monthly by blind raters for toddlers with ASD participating in an randomized control trial of parent-mediated treatment (N = 42, 12–30 months). Findings revealed that toddlers acquired skills following a reliable (vs. idiosyncratic) sequence and the majority of toddlers combined gestures with words before combining words in speech, but in contrast to the pattern observed in typical development, a significant subset acquired pointing after first words.  相似文献   
25.
Research Findings: This study examined whether children’s outcomes at age 3 were predicted by their experiences in Early Head Start (EHS), focusing on 2 key features of infant and toddler care: (a) stability of care and (b) teacher–child interactions. This study further explored potential interaction effects between stability of care and teacher–child interactions in predicting child outcomes. Three main results were found from secondary analyses of the recently released EHS longitudinal data set the EHS Family and Child Experiences Study (Vogel & Boller, 2009–2012). First, children who had stability of care (no teacher change) were rated as having fewer behavior problems and higher social competence. Second, children were rated as demonstrating better orientation/engagement and emotional regulation when they were in EHS classrooms observed to have higher emotional and behavioral support. Third, teacher–child interactions that are emotionally and behaviorally supportive may mitigate the potential drawbacks of experiencing instability of care on early social-emotional development. Study implications are discussed. Practice or Policy: Both stability and quality teacher–child interactions are important in center-based infant and toddler care, and ensuring quality teacher–child interactions is particularly important for children who experience teacher changes during their infant and toddler years.  相似文献   
26.
Lee K  Kim C  Young Yang J  Lee H  Ahn B  Xu L  Yoon Kang J  Oh KW 《Biomicrofluidics》2012,6(1):14114-141147
We propose a simple method for forming massive and uniform three-dimensional (3-D) cell spheroids in a multi-level structured microfluidic device by gravitational force. The concept of orienting the device vertically has allowed spheroid formation, long-term perfusion, and retrieval of the cultured spheroids by user-friendly standard pipetting. We have successfully formed, perfused, and retrieved uniform, size-controllable, well-conditioned spheroids of human embryonic kidney 293 cells (HEK 293) in the gravity-oriented microfluidic device. We expect the proposed method will be a useful tool to study in-vitro 3-D cell models for the proliferation, differentiation, and metabolism of embryoid bodies or tumours.  相似文献   
27.
28.
In this paper, we demonstrate for the first time that insulative dielectrophoresis can induce size-dependent trajectories of DNA macromolecules. We experimentally use λ (48.5 kbp) and T4GT7 (165.6 kbp) DNA molecules flowing continuously around a sharp corner inside fluidic channels with a depth of 0.4 μm. Numerical simulation of the electrokinetic force distribution inside the channels is in qualitative agreement with our experimentally observed trajectories. We discuss a possible physical mechanism for the DNA polarization and dielectrophoresis inside confining channels, based on the observed dielectrophoresis responses due to different DNA sizes and various electric fields applied between the inlet and the outlet. The proposed physical mechanism indicates that further extensive investigations, both theoretically and experimentally, would be very useful to better elucidate the forces involved at DNA dielectrophoresis. When applied for size-based sorting of DNA molecules, our sorting method offers two major advantages compared to earlier attempts with insulative dielectrophoresis: Its continuous operation allows for high-throughput analysis, and it only requires electric field strengths as low as ∼10 V∕cm.  相似文献   
29.
The intent of this study was to assess the perceptions and actions of Wyoming principals concerning their role in supervising and evaluating teachers. A survey was sent to all 286 principals in the state of Wyoming, of which, 143 returned surveys, a response rate of 50%. Findings suggested that principals utilized supervisory behaviors more often than evaluative behaviors. Elementary principals perceived their evaluative practices as significantly more prevalent than secondary principals. Furthermore, principals indicated that their greatest frustrations in supervising teachers were time, the evaluation instrument, and teachers’ unwillingness to change. Additionally, findings suggested that Wyoming principals utilized classroom walkthroughs because they provided a snapshot of teaching and provided a medium for providing feedback. In regards to developmental supervision, principals indicated that novice teachers received much more supervision than veteran teachers. However, their reported use of differentiated supervision only applied to teacher autonomy concerning professional development goals. Principals reported that teachers had little input concerning the methods by which they were supervised. Finally, a majority of the Wyoming principals felt that improvement plans were effective at changing mediocre teaching behaviors, but 40% were speculative that such plans truly remediated poor teachers.  相似文献   
30.
Science education reforms worldwide call on teachers to engage students in investigative approaches to instruction, like inquiry. Studies of teacher self-reported enactment indicate that inquiry is used frequently in the classroom, suggesting a high level of proficiency with inquiry that would be amenable to inquiry reform. However, it is unclear whether the high frequency of self-report is based on sound knowledge inquiry. In the absence of sound knowledge, high rates of self-reported enactment would be suspect. We conducted a study to measure teachers’ knowledge of inquiry as it related to the known, high frequency of reported enactment. We developed a multidimensional survey instrument using US reform documents and administered it to 149 K–12 teachers at a national science teachers’ conference. The majority of the teachers surveyed did not report inquiry enactment based on well-structured knowledge of inquiry. Interviews with participants showed how teachers could readily map non-inquiry activities onto inquiry statements taken directly from reform documents. From these results we argue that teachers often believed they were enacting inquiry, when likely they were not. We further reason that teachers may struggle to interpret and enact inquiry-related requirements of science education reform and will need support distinguishing inquiry from non-inquiry practices.  相似文献   
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