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1.
本概述了近年来EMA技术的研究.开发与工程化的进展情况,从中可以看出:EMA检测技术已进入了工程应用阶段,特别是在冶金工业中,它的应用已趋成熟,在机械制造,能源和铁道和铁道运输工业中,已开始进入了工程应用阶段,但其基础性研究工作,尚待努力加强。  相似文献   

2.
当前,人类正进入信息化时代;这是微电子技术、光电子技术、通信技术、计算机科学与技术、自动化、精密机械等应用性很强的科学技术综合发展的结果.在迈人信息化社会的进程中,光电子技术起着十分重要的作用.它是继微电子技术之后,近十几年来迅速发展的新兴高科技,集中了固体物理、导波光学、材料科学、微细加工和半导体的科研成就,成为电子技术与光子技术的自然结合与扩展,是具有强烈应用背景的新兴交叉学科.这些都说明了从电荷-电子-电子学-电子工程-电子技术到光-光子-光子学-光子工程-光子技术发展的必然趋势,也是从量子力学(实物)到量子电动力学、量子场论(场)发展的必然结果:信息技术的发展在20世纪是由电子学向光电子学发展的阶段;  相似文献   

3.
介绍了DSP6701在数字图像处理中的应用,包括硬件组成、软件设计原理、DMA通道技术、部分程序代码等。本系统在实际工程中已得到应用,并且系统稳定,图像处理的速度能达到系统的实时性要求。  相似文献   

4.
 自30年代起医学上就已开始应用原子核来治疗疾病,到了60年代核医学进入发展阶段,80年代开展了γ照相和放射性核素发射计算机断层摄影术,进行了体外竞争放射分析法的各项实验,由此进入了现代核医学的高级发展阶段。核医学是研究放射性核素及其辐射线的医学应用、医学理论基础的新兴学科。  相似文献   

5.
引言到1980年7月8日止,激光发展已整整20年了。从1916年爱因斯坦的受激辐射理论作为激光的基础理论研究算起,激光大致上经历了三个阶段: 1.1960年前,基础研究阶段; 2.1960年~1970年,广泛探索激光体系以及激光与物质相互作用的研究,可称之为应用基础研究和应用研究阶段; 3.1970年~1980年,激光的应用、推广试制和生产的规模,逐渐超过基础和应用基础研究的规模,是重大应用及相应理论和技术发展阶段,也是激光器从实验室走向工程规模的阶段。  相似文献   

6.
辐射度学、光度学和色度学(以下简称"三度学")是现代光电信息转换、传输、存储、显示、测量和计量的基础,随着光电信息技术、图像技术的发展和应用的扩展,"三度学"及其测量技术已成为光电工程领域科研和应用人员必备的专业基础知识和技术,在国内还没有完全类似的教材和课程设置。以往教学中仅在某些课程中部分涉及辐射度学和光度学的概念,难以使学生全面地掌握和应用相关的知识,至于色度学则更少涉及,系统讲授的课程大多安排在研究生阶段,但也较少涉及相关的实验仪器和技术的讲授。从光电信息科学与工程类专业知识体系结构的角度出发,总结了多年教学科研的经验,探索了以"三度学"作为教学内容,通过配合相关测量的实验,开展了"三度学"课程建设的探索。  相似文献   

7.
近红外光谱检测技术在害虫检测中的应用   总被引:3,自引:0,他引:3  
近红外光谱是20 世纪80 年代以来发展最快、最引人注目的光谱分析技术。以其快速、无损伤、操作简单、稳定性好、效率高等特点,在仓储害虫检测、种子害虫侵染检测和林草害虫危害检测中的应用已成为一个活跃的研究领域。而近红外光谱技术在我国害虫检测中的研究和应用则较少,处于刚刚起步阶段。因此,文章介绍了利用近红外光谱技术检测的基本原理, 综述了国内外利用近红外光谱技术检测农林业害虫的应用情况,并对近红外检测技术在害虫检测上的应用进行了展望,以期推动近红外光谱技术在我国害虫检测科技和生产中的应用。  相似文献   

8.
随着科学技术的进步,制造业进入了企业信息化发展的阶段,而有关产品的各种工程信息在设计、生产、销售、服务等整个产品寿命周期中的畅通流动是实现信息化的关键环节之~,其中,快速、准确地获取有效的工程信息是保证信息畅通流动的基础,因此工程信息提取技术在业界得到了广泛的关注和发展。工程信息中的非几何特征信息(以设计图纸的标题栏和明细表信息为代表)表达了产品结构、零部件属性、装配关系及所属关系等产品特征,另外,该信息还贯穿了整个产品寿命周期,因此,提取此类信息并进行有机的组合不仅从总体上体现了产品轮廓特征,也是实现产品配置管理、信息集成、数据共享的重要基础,  相似文献   

9.
目前一些超导电力装置已进入试验运行阶段,为适应不久的将来超导电力技术应用的商品化,对一些有代表性的超导电力装置的试验、检测方法及其主要设备进行研究是十分必要的。文中从超导变压器的电磁特性出发,探讨了超导变压器的试验、检测项目;重点介绍了其超导电磁特性试验,并阐述了超导变压器的试验方法及其主要设备。  相似文献   

10.
《现代物理知识》2008,(4):51-51
中国科学院高能物理所于7月22曰举行新闻发布会,正式对外宣布北京正负电子对撞机重大改造工程(BEPCII)取得重要进展——加速器与北京谱仪联合调试对撞成功,并观察到了正负电子对撞产生的物理事例,各种设备工作正常。这是BEPCII工程的重要里程碑,标志着BEPCII高质量、按计划地圆满完成了建设任务,即将进入试运行阶段。  相似文献   

11.
The classic experimental modal analysis (EMA) is a well-known procedure for determining the modal parameters. The less frequently used strain EMA is based on a response measurement using strain sensors. The results of a strain EMA are the modal parameters, where in addition to the displacement mode shapes the strain mode shapes are also identified. The strain EMA can be used for an experimental investigation of a stress–strain distribution without the need to build a dynamical model. It can also be used to determine the modal parameters when, during modal testing, a motion sensor cannot be used and so a strain sensor is used instead. The displacement and strain mode shapes that are determined with the strain EMA are not mass normalized (scaled with respect to the orthogonality properties of the mass-normalized modal matrix), and therefore some dynamical properties of the system cannot be obtained. The mass normalization can be made with the classic EMA, which requires the use of a motion sensor. In this research a new approach to the mass normalization in the strain EMA, without using a motion sensor, is presented. It is based on the recently introduced mass-change structural modification method, which is used for the mass normalization in an operational modal analysis. This method was modified in such a way that it can be used for the mass normalization in the strain EMA. The mass-normalized displacement and strain mode shapes were obtained using a combination of the proposed approach and the strain EMA. The proposed approach was validated on real structures (beam and plate).  相似文献   

12.
The kinetics of multi-site phase-transfer catalyzed free radical polymerisation of ethyl methacrylate (EMA) using potassium peroxy disulphate (PDS) as a water soluble initiator and newly synthesized 1,4-dihexadecylpyrazine-1,4-diium dibromide as multi-site phase-transfer catalyst (MPTC) has been investigated in ethyl acetate/water two phase system at constant temperature 55 ± 1 °C under nitrogen atmosphere and ultrasound irradiation conditions. The rate of polymerization increases with an increase in concentrations of EMA, PDS and MPTC. The order with respect to monomer, initiator and MPTC were found to be 1.03, 0.52 and 0.53, respectively. Based on the observed results a suitable mechanism has been proposed to account for the experimental observations and its significance was discussed.  相似文献   

13.
乐开端 《光子学报》1998,27(6):558-562
本文对激光散斑物体轮廓及形变测量和相移轮廓测量原理进行类比,首次提出大动态范围物体三维轮廓及形变测量方法。该方法具有测量原理简单、系统操作简便、测量精度高、测量动态范围大等特点,形变测量范围从亚微米级到毫米级。另外本文还推导了基于减模式激光散斑物体轮廓及形变测量的相位值计算公式。  相似文献   

14.
复杂轮廓表面激光检测及三维重构技术的研究   总被引:4,自引:0,他引:4  
赵勇  廖延彪  赖淑蓉 《光学技术》2002,28(2):172-173
基于零件实物样件的几何模型反求技术已成为CAD/CAM领域中的研究热点之一。以航空航天用MJ螺纹为对象 ,对逆向工程中的两大关键技术———表面数字化及三维重构技术进行了分析和研究。提出了用一种新型激光光纤传感器实现复杂轮廓表面的非接触数字化检测方法 ,描述了测量原理。通过二维截面轮廓图重构三维面型 ,初步的实验结果验证了此方法的有效性和实用性  相似文献   

15.
林旭升  陈雄文  兰胜 《中国物理》2005,14(10):2033-2040
The analytical expression for the transmission spectra of coupled cavity waveguides (CCWs) in photonic crystals (PCs) is derived based on the coupled-mode theory (CMT). Parameters in the analytical expression can be extracted by simple numerical simulations. We reveal that it is the phase shift between the two adjacent PC defects that uniquely determines the flatness of the impurity bands of CCWs. In addition, it is found that the phase shift also greatly affects the bandwidth of CCWs. Thus, the engineering of the impurity bands of CCWs can be realized through the adjustment of the phase shift. Based on the theoretical results, an interesting phenomenon in which a CCW acts as a single PC defect and its impurity band possesses a Lorentz lineshape is predicted. Very good agreement between the analytical results and the numerical simulations based on transfer matrix method has been achieved.  相似文献   

16.
Finding the control parameters of an articulatory model that result in given acoustics is an important problem in speech research. However, one should also be able to derive the same parameters from measured articulatory data. In this paper, a method to estimate the control parameters of the the model by Maeda from electromagnetic articulography (EMA) data, which allows the derivation of full sagittal vocal tract slices from sparse flesh-point information, is presented. First, the articulatory grid system involved in the model's definition is adapted to the speaker involved in the experiment, and EMA data are registered to it automatically. Then, articulatory variables that correspond to measurements defined by Maeda on the grid are extracted. An initial solution for the articulatory control parameters is found by a least-squares method, under constraints ensuring vocal tract shape naturalness. Dynamic smoothness of the parameter trajectories is then imposed by a variational regularization method. Generated vocal tract slices for vowels are compared with slices appearing in magnetic resonance images of the same speaker or found in the literature. Formants synthesized on the basis of these generated slices are adequately close to those tracked in real speech recorded concurrently with EMA.  相似文献   

17.
叶浩亮  李飞  王松林 《应用声学》2017,25(5):218-221
锂-亚硫酰氯电池作为一种免维护、高比能、长储存寿命电池,目前已经在以国防领域为代表的国民经济中得到了广泛应用;其储存寿命的考核在行业内尚属难题;通过广泛、深入地调研和对前期锂-亚硫酰氯电池储存数据的收集整理,研究了锂-亚硫酰氯电池的储存寿命影响因素及其试验评估方法;通过研究得知,锂-亚硫酰氯电池的储存寿命试验应尽早备样,若时间紧迫可通过加速试验方法;提出了通过等效储存试验时间来评估电池储存寿命及其可靠度的方法,指出当等效储存试验时间不足时,应安排样本进行容量回归分析,得出其退化规律;此外,还要对电池储存末期热性能进行分析;在以上工作基础上对电池储存寿命进行综合评估;最后,通过案例分析,进行了工程演算;为后续锂-亚硫酰氯电池储存寿命评估提供了参考。  相似文献   

18.
Quantum phase properties of photon added and subtracted displaced Fock states (and their limiting cases) are investigated from a number of perspectives, and it is shown that the quantum phase properties are dependent on the quantum state engineering operations performed. Specifically, the analytic expressions for quantum phase distributions and angular Q distribution as well as measures of quantum phase fluctuation and phase dispersion are obtained. The uniform phase distribution of the initial Fock states is observed to be transformed by the unitary operation (i.e., displacement operator) into non‐Gaussian shape, except for the initial vacuum state. It is observed that the phase distribution is symmetric with respect to the phase of the displacement parameter and becomes progressively narrower as its amplitude increases. The non‐unitary (photon addition/subtraction) operations make it even narrower in contrast to the Fock parameter, which leads to broadness. The photon subtraction is observed to be a more powerful quantum state engineering tool in comparison to the photon addition. Further, one of the quantum phase fluctuation parameters is found to reveal the existence of antibunching in both the engineered quantum states under consideration. Finally, the relevance of the engineered quantum states in the quantum phase estimation is also discussed.  相似文献   

19.
Atomic spectrometry research is the life-blood of the atomic spectrometry instrument industry. The instrument designer can be expected to innovate in the execution of instrumentation and should be expected to be the expert in optical, electronic and software engineering. Fundamentally new technology has required too long a period of gestation to be compatible with commercial time scales and budgets. But in the past decade, the pressure from stockholders for increased return on investments has put increasingly strong pressure on management to reduce expenses and focus increasingly on projects that guarantee a fast payback. This pressure falls particularly heavily on the larger companies; the same companies that a decade or more ago were the ones that brought the more far-reaching and expensive new concepts to market. Fundamental research in atomic spectrometry has been accomplished in the past several decades mostly in the academic environment and in research institutions that are Federally funded. All of the Federally funded research institutions have been forced to alter their missions to more tangible and immediate goals, and many have also seen severe financial reductions.  相似文献   

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