理工科院校仪器分析课程教学改革探索

仪器分析是理工科院校化学及相关学科本科生的专业基础课程。本文针对仪器分析课程具有的前沿性、发展性、实践性和应用性等特点及在教学中存在的问题,提出了仪器分析课程教学改革的思路。     

2011年全国高等学校物理基础课程教育学术研讨会第一轮通知

经教育部高等学校物理基础课程教学指导分委员会与中国物理学会物理教学委员会高校分委员会协商,拟定于2011年7月（具体日期和其他事项在第二轮通知中和会议网页上通知）在郑州大学召开”2011年全国高等学校物理基础课程教育学术研讨会”．欢迎广大高校物理教师参加,踊跃投稿．     

从一道例题的解法说起

数学的核心是问题和解,数学教学中教师应引导学生自然地、合理地提出问题、解决问题和拓展问题．教学设计应该顺应学生已有的知识能力基础,知识的深入应符合其思维发展空间,使其大脑中固有的知识和思维方式一经点拨便能豁然开朗．     

征稿简则

简介：《中国科学：数学》创刊于1950年,主要报道数学基础研究与应用研究方面具有重要意义的研究成果,是数学科学领域的综合性学术期刊．由中国科学院与国家自然科学基金委员会主办、《中国科学》杂志社出版,现为月刊,网络版每月1日出版,印刷版每月20日出版．     

征稿简则

简介：《中国科学：数学》创刊于1950年,主要报道数学基础研究与应用研究方面具有重要意义的研究成果。是数学科学领域的综合性学术期刊．由中国科学院与国家自然科学基金委员会主办．《中国科学》杂志社出版,现为月刊,网络版每月1日出版,印刷版每月20日出版．     

征稿简则

简介：《中国科学：数学》创刊于1950年,主要报道数学基础研究与应用研究方面具有重要意义的研究成果,是数学科学领域的综合性学术期刊．由中国科学院与国家自然科学基金委员会主办、《中国科学》杂志社出版,现为月刊,网络版每月1日出版,印刷版每月20日出版．     

征稿简则

简介：《中国科学：数学》创刊于1950年,主要报道数学基础研究与应用研究方面具有重要意义的研究成果,是数学科学领域的综合性学术期刊．由中国科学院与国家自然科学基金委员会主办、《中国科学》杂志社出版,现为月刊．网络版每月1日出版,印刷版每月20日出版．     

Study of the excitation properties of the Si3O2 cluster under an external electric field

The structure of the Si₃O_x (x=2, 3) cluster is investigated; we find that the geometry of Si₃O₂ is similar to that of Si₃O₃ except for the oxygen-deficient defect structure (Si-Si band) which exists only in the Si₃O₂ cluster. It is known that oxygen-deficient defects are used to explain visible luminescence (especially blue, purple and ultraviolet light) from silicon-based materials, which are directly bound up with the excited states of the molecules. Therefore the excitation properties of the two clusters are also studied. Our results show that the absorption spectrum of Si₃O₂ is concentrated in the visible light region. In contrast, the absorption spectrum of Si₃O₃ is mainly located in the ultraviolet light region. The calculations are perfectly consistent with experimental data and also support the theory of oxygen-deficient defects.     

Proposal of metal bellows-based fiber Bragg grating accelerometer

A metal bellows-based fiber Bragg grating(FBG) accelerometer is proposed and experimentally demonstrated. The optical fiber(containing the FBG) is pre-tensioned,and the two ends of the optical fiber are fixed directly from the shell to the inertial mass. In this design,the FBG is uniformly tensioned to obtain a constant strain distribution over it. By employing this configuration,the FBG always has a sharp reflection characteristic with no broadening in its reflection spectrum during wavelength shifting. Dy...     

Eigenspace-based source number estimation for direction-of-arrival estimation

A eigenspace-based source number estimation was presented.It projects the estimated covariance matrix of array signal into signal eigen-subspace and noise eigen-subspace, respectively.Using the orthogonality between signal eigen-subspace and noise eigen-subspace, it is easy to differentiate the contribution of signal and noise by using the criterion value,or the magnitude of projection.Like the Direction-of-Arrival(DOA) estimation algorithm,the estimator uses the eigenvalue decomposition of covariance matrix with order M×M,where M is the number of elements,and hence can save much computational burden.To reduce more computational burden,the estimation can be implemented by the decomposition in the real-value space.Computer simulation demonstrates the distribution of criterion value and the performance of the estimation method.The estimation method was also tested with the sonar data,which shows good performances.