首页 | 本学科首页   官方微博 | 高级检索  
文章检索
  按 检索   检索词:      
出版年份:   被引次数:   他引次数: 提示:输入*表示无穷大
  收费全文   135篇
  免费   12篇
  国内免费   7篇
化学   26篇
力学   17篇
综合类   6篇
数学   74篇
物理学   31篇
  2022年   3篇
  2021年   6篇
  2020年   4篇
  2019年   6篇
  2018年   5篇
  2017年   5篇
  2016年   3篇
  2015年   2篇
  2014年   3篇
  2013年   15篇
  2012年   5篇
  2011年   4篇
  2010年   3篇
  2009年   3篇
  2008年   5篇
  2007年   7篇
  2006年   9篇
  2005年   7篇
  2004年   11篇
  2003年   1篇
  2002年   5篇
  2000年   2篇
  1999年   7篇
  1998年   2篇
  1996年   1篇
  1995年   3篇
  1994年   5篇
  1993年   2篇
  1992年   4篇
  1991年   1篇
  1990年   1篇
  1989年   1篇
  1988年   2篇
  1987年   1篇
  1986年   3篇
  1985年   3篇
  1981年   1篇
  1979年   1篇
  1975年   1篇
  1974年   1篇
排序方式: 共有154条查询结果,搜索用时 468 毫秒
1.
交互分类是解决数据复杂分类问题的主要手段之一。在现有的大多交互分类系统中,用户能准确识别数据类别,但在有些分类场景中,类别之间的顺序关系更容易被识别,为此,提出一种排序支持的交互数据分类算法。为提升交互分类精度,引入数据的顺序信息,为降低标记难度,提出候选样本推荐策略。另外,提出一种评估分类算法性能的可视化方法,用包含基本车况、交通违法记录、交通事故记录等信息的车辆数据集进行实验验证,将相关车辆分为高危车辆、中危车辆、低危车辆3类,算法的分类结果模型一致度达近98%,验证了方法的有效性。  相似文献   
2.
基于核心概念教学的思路,国际IB课程互联网B/S架构交互式软件能够使学生围绕“电解质”核心概念,通过自行操作软件获得多个从微观到宏观、定性与定量相结合、可视化的实验证据,有利于学生深度理解概念与概念之间的逻辑和发展关系,促进学科知识系统框架的形成。  相似文献   
3.
The paper deals with the simulation program Off Road Systems Interactive Simulation (ORSIS) which is the w,orldwide leading simulation tool for off road driving of wheeled vehicles. Even though the present state of development allows a very realistic simulation of the man–vehicle–terrain system, there is continuous further improvement in the computer program’s detail. Some of the recent innovations integrated into the program are presented in this paper. These examples were chosen in a way that the scope of the further developments can be demonstrated. They represent three main directions of the work carried out: the refining of the tire–soil-model, the integration of new technologies and subsystems into the vehicle model and the improvement of the man–machine–interface especially in driving simulators.The first part of the paper describes a further development of the tire–soil-model. A significant improvement has been achieved to include the influence of slippery surfaces on traction in combination with the tire tread pattern. Results from finite element method (FEM) as well as real measurements were used to build up an approach, which qualitatively allows the influence of the positive–negative portion of the tire tread and the lug height of the tire tread on traction to be considered. The basic idea is very simple and straightforward. Moreover the calculation costs are very low, so the enhancement does not affect real time operation.In the second part a physical model for the central tire inflation system (CTIS) is presented. With this model it is possible to simulate the complete pneumatic system of a CTIS, including the air compressor with an accumulator, the pressure line and the wheel valves. The components are modelled by their physical parameters, so an adaptation to different existing tire-pressure-control-systems (TPC) can be made. The paper presents a short review of the modelling and a first validation using real measurements. Furthermore the influence of each parameter, e.g. the discharge flow of the compressor on the inflation time, is presented.The third part of the paper describes a further development of the visualization system. The ORSIS OpenGL graphic engine was separated from the main ORSIS simulation and can be run on different PCs controlled via a network. It is therefore possible to build up very cheap multi-channel visualization systems using consumer PCs running under LinuX. The fact that ORSIS itself is running on a normal PC allows the assembly of comparatively cheap driving simulators of a high end simulation quality.  相似文献   
4.
波纹钢屋盖结构板件相关屈曲的试验研究与分析   总被引:2,自引:1,他引:2  
高轩能  吴丽丽 《实验力学》2004,19(1):113-119
拱型波纹钢屋盖结构的受力机理异常复杂,波纹、加工制作过程中产生的变形和残余应力等初始缺陷在理论分析中很难精确定量描述。论文对波纹钢屋盖结构梯形截面板组进行了轴心和偏心压力作用下稳定承载能力的试验研究,并与理论结果进行了比较分析,试验与理论结果吻合较好。试验结果表明波纹板组具有较高的局部屈曲承载能力,但几乎无屈曲后承栽能力,与平板板组屈曲特性相比有显著差异。  相似文献   
5.
Interactive music uses wearable sensors (i.e., gestural interfaces—GIs) and biometric datasets to reinvent traditional human–computer interaction and enhance music composition. In recent years, machine learning (ML) has been important for the artform. This is because ML helps process complex biometric datasets from GIs when predicting musical actions (termed performance gestures). ML allows musicians to create novel interactions with digital media. Wekinator is a popular ML software amongst artists, allowing users to train models through demonstration. It is built on the Waikato Environment for Knowledge Analysis (WEKA) framework, which is used to build supervised predictive models. Previous research has used biometric data from GIs to train specific ML models. However, previous research does not inform optimum ML model choice, within music, or compare model performance. Wekinator offers several ML models. Thus, we used Wekinator and the Myo armband GI and study three performance gestures for piano practice to solve this problem. Using these, we trained all models in Wekinator and investigated their accuracy, how gesture representation affects model accuracy and if optimisation can arise. Results show that neural networks are the strongest continuous classifiers, mapping behaviour differs amongst continuous models, optimisation can occur and gesture representation disparately affects model mapping behaviour; impacting music practice.  相似文献   
6.
Colligative properties of dilute solutions are the basic contents for chemistry, chemical engineering and biomedicine majors. The teaching model of multidimensional interact takes teachers as the leader and students as the main body. Through the multi-dimensional interaction among teachers and students, students and groups, students' interest in learning, strong sense of cooperation and independent learning ability can be cultivated. This paper introduces the implementation process of the multi-dimensional interactive teaching mode of "colligative properties of dilute solutions", which includes clarifying the purpose of interaction, constructing learning groups, raising interactive questions, launching interactive activities and implementing interactive evaluation, etc. Multi-dimensional teaching goals can be achieved through group explorations, group presentations and group discussions.  相似文献   
7.
After the invasion and occupation of their land by Europeans, Indigenous Australians were expected to benefit from a Western education system based on that of the dominant Europeans. Gradually educators realized that Aboriginal children learn differently and that Indigenous culture and pedagogy has validity and strength. Of course, educators also need to be acutely aware of the diversity of Indigenous cultures in Australia and that there is not a monolithic sense of Aboriginal identity or Aboriginal pedagogy. Dispossession and alienation, poor health and few employment opportunities must also affect educational interest, attendance, application and performance. In this paper the characteristics of Indigenous learners are examined and pedagogical strategies to assist in both students' learning and teachers' delivery are explored. The message conveyed in this paper has particular relevance for teaching mathematics to Aboriginal learners. It is also of considerable value in teaching mathematics to nonAboriginal students, in Australia and elsewhere.  相似文献   
8.
冲蚀磨损与冲蚀、空蚀交互磨损的对比研究   总被引:1,自引:0,他引:1  
基于计算流体力学(computational fluid dynamics,CFD)方法,数值对比研究了在模拟水轮机工况中不同转速时,冲蚀与冲蚀、空蚀交互作用时,转盘表面的流场(压力场、流体浓度分布),然后在转盘式磨损装置上,进行了汽液固三相冲蚀与空蚀交互磨损试验.结果表明:对于冲蚀磨损来说,随着转速增加,压力增大,在冲蚀作用下加入空蚀磨损,压力增高,磨损加剧;而对于交互磨损来说,随着转速增加,转盘表面的空蚀磨损区域从空化孔附近开始沿着转盘旋转的反方向偏移,并且磨损程度加剧;数值计算的气泡较多且压力梯度较高区域和试验转盘磨损区域基本一致,数值计算结果和试验结果吻合得较好.  相似文献   
9.
Navigation augmentation technology is one of the most common methods to increase the continuity,reliability and integrity of the global satellite navigation system.The concept of volunteer augmentation navigation (VNA) is proposed and the elements and topological structure of VNA are also analyzed in this paper.The study focuses on the neural network model that volunteers and ordinary users use modern communication information network to exchange self-organizing information.The neural cell model of Voluntee...  相似文献   
10.
为了更好地解决决策者具有(严格)凸性偏好结构下的多目标决策问题,一般目标空间为有界凸域的情形常常可以转化为目标空间为有界闭凸区域的情形,首先分析了切割平面及该平面上偏好最优点与被切割平面分割成的为有界闭凸区域的目标空间或目标空间的子集的两个部分之间的关系;然后分析并指出了对于包含全局偏好最优目标方案点的为有界闭凸域的目标空间及其子集(准最优目标集),在确定了切割平面上的偏好最优点后,通过适当地选取供决策者与切割平面的偏好最优点进行比较判断的目标方案点,经过一次比较就可以确定一个新的范围更小的包含全局偏好最优目标方案点的目标空间的有界闭凸子区域(准最优目标集).为获取切割平面上的偏好最优点,提出了改进的坐标轮换法.在这些结论和方法的基础上,提出了决策者具有(严格)凸性偏好结构下的一类交互式多目标决策方法,要求决策者提供较易的偏好性息,决策效能较好.  相似文献   
设为首页 | 免责声明 | 关于勤云 | 加入收藏

Copyright©北京勤云科技发展有限公司  京ICP备09084417号