近红外透射技术分析大豆籽粒

本文建立了近红外透射技术 (NIT)分析大豆样本的新方法 ,批量地分析了大豆子粒的水分、蛋白、脂肪 ,定标误差分别为 0 .36 9、0 .5 78、0 .4 6 0 ,相关系数分别为 0 .95 8、0 .913、0 .912。通过 30个样本的独立样品集的定标验证 ,预测误差分别为 0 .4 0 4、0 .6 2 2、0 .5 0 8,相关系数分别为 0 .95 2、0 .90 1、0 .90 8。结果表明 ,近红外光谱技术用于测试大豆品质是可行的 ,可用于育种的早代选择     

新型发蓝光材料的合成和光谱表征及光致和电致发光性能的研究

合成了能发射蓝光的锌的配合物.对配合物进行了元素分析、激发光谱、发射光谱、红外光谱进行了研究.利用配合物制成发光二极管的发光层,对其光致和电致发光性能进行了探讨.它能发射蓝光,波长为455 nm,亮度为37.20 cd·m-2 .     

应用声学(双月刊)1990年第9卷第1—6期 总目录

题目作者期页、J尹电,户、.2、.1/‘、Z吸、了.、‘‘、.工飞︸户O︸61)5)幻劝5)1)匀l)灼劝分2)5)幻叼幻z)盯l)DI)幻0)劝5)0)力幻l)幻 -1,曰--,曰,‘二J弓j-,‘,曰飞︸月j-l-,‘,.︸乙‘了、沙了、了‘、产‘、声了、Z‘、尹‘﹄Z‘、Z、/‘、了‘、/‘、/‘、/L、/‘、2.、了‘、产吸、/哎、了、户‘、了‘、尹‘、厂吸、了、/‘、了‘﹄z、/‘、/‘、1 1 ..几1 1.‘22内乙,‘,山,‘2.、︸;︸.J .j二J;︸;︸44月,44月,4月,哎沙︸,5(15)‘、产、少、,了、了、产﹄,了、.2、‘工‘、声了nU 工工JQ夕1二﹃6Q夕月,no几j,翻,‘,‘,‘11,…     

2012年北京市高中新课程高考物理试卷评析

对2012年北京市新课程高中物理试卷做了比较全面、深刻的评析.对试卷形成的特色做了阐述.对试卷的正确导向作用做了说明.对高考命题提出了一些建议.     

我是怎样喜欢上物理的

 我从小学起,就比较喜欢数学,上初中以后,有了物理课,也就自然而然地对物理产生了浓厚的兴趣.而我真正迷上物理,还是高二的事.高二时,我们开设了选修课,我选学了物理实验.虽然每周只有一个下午的选修课,但它却使我一下发现了一个新天地.主持选修课的刘滨生老师很重视对实验设计的训练,特别突出了实验中严谨、细致作风的培养.也许正是这种严谨、细致的要求,恰恰与我沉稳、耐心的性格相符.因此,我在实验中能够比较得心应手,从中获得了很大的乐趣.这时,我才真正领会到了学物理的快乐.     

植物药分析

植物药在世界范围内已经得到了广泛使用,对人类的健康发挥着重要作用. 植物药分析是新药、保健食品研发的重要途径. 目前,植物药分析方法主要包括传统分析法和联用技术分析法. 传统分析法的步骤包括植物药成分提取、分离和结构鉴定. 联用技术分析法主要是色谱、质谱、核磁共振等技术的联用. 该文对植物药分析的方法尤其是联用技术在植物药分析中的应用进行了综述,重点介绍了HPLC-DAD-SPE-NMR-MS联用技术.     

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介绍了HL-2A装置上用于二级加热系统的PSM高压脉冲电源的反馈控制系统.该电源控制系统以DSP+FPGA作为控制核心,输出112路驱动脉冲,以此来控制112个IGBT的通断,包括了驱动、通信、计算、反馈等部分,使电源系统输出稳定高压.设计了远程通信系统,其中基于VB的上位机与控制系统之间采用CAN总线技术来实现电源系统的相关参数设定及传输.DSP与FPGA实现了计算、反馈等功能.完成了相关的代码编写与系统测试.实验测试结果表明,该控制系统实现了高压电源的稳定输出,满足了实验的需求.     

药物核磁共振定量分析参数的研究

药物核磁共振定量分析已见诸多篇报道. 英、美、欧药典中都先后引入了核磁共振分析方法.本文对药物核磁共振定量分析的参数作了较为详尽的研究,提出了选择定量特征峰的新标准.经维生素C实际样品测定其精密度优于1%,结果满意.     

电子显微镜技术与物理学和材料科学

 从1931年E.Ruska在德国柏林工业大学研制成功第一台电子显微镜算起,已经整整58年了.它的出现,为人类揭示丰富多采的物质微观世界的奥秘提供了强有力的手段.现在,从电镜成像理论、实验技术,以及图像的分析原理和方法,都已自成体系,十分完善,并综合成为一门新的学科--电子显微学.电镜技术已经在固体物理学、材料科学、电子学、地质矿物、晶体化学以及生物医学等各个领域,得到了广泛的应用,取得了丰硕的研究成果.电子显微学和电子理论、晶体缺陷理论并称为近代材料科学的三大支柱.     

原子、分子和纳米材料中非线性高次谐波的产生:一个潜在的极超快和高能量的新型光源

在原子、分子和纳米材料中的高次谐波为非线性光学开辟了一个崭新的研究领域.其响应时间之短、能量之高,引起了人们的高度重视.目前的研究达到了白热化的程度.还有很多问题没有解决.文章首先简要地介绍了这一个新的领域.然后用一个简单的例子引出有名的辐射截断方程,最后用C60作为一个例子说明如何详细地计算辐射能量谱.     

Pulse stabilization by high-order dispersion management

The stabilizing effects of dispersion management (DM) at second and third order are studied for both single-channel and wavelength-division multiplexed (WDM) systems. We first derive a model for the slow evolution of a pulse in an optical fiber with high-order dispersion management (HODM). For single-channel systems, in contrast with conventional DM with constant third-order dispersion, this equation possesses a stable solution, the ground state for its associated Hamiltonian, which propagates nearly periodically under direct numerical simulation. Improved performance for WDM systems is also observed, as complicated pulse interactions, which can lead to undesirable effects such as frequency shift, are prevented by HODM.     

Interchannel pulse collision in a wavelength-division-multiplexed system with strong dispersion management

We develop a perturbation theory to analytically calculate the effects of complete and incomplete interchannel collisions of Gaussian pulses in a wavelength-division-multiplexed system with strong dispersion management. We show that, for complete collisions, the collision-induced frequency shift of a Gaussian pulse is negligible, whereas its position shift is significant and can be found in a simple analytical form. For strong dispersion management we find that incomplete collisions can be neglected, whereas for dispersion management of moderate strength the contribution of the incomplete collisions can be significant. The analytical predictions are in satisfactory agreement with numerical results. We also give an estimate of the limit imposed on the transmission distance by such collisions.     

具有全方位光管理能力的光阱结构

本文提出了一种基于砷化镓(GaAs)材料且具有全方位光管理能力的纳米方形光阱结构.通过光学模拟可知,该结构在较大结构参数范围内具有优异的全向光管理能力.当该结构的有效厚度为407 nm时,在AM1.5G光照下,其光电流密度可达29.51 mA/cm~2,而在同样条件下,2000 nm厚的平面GaAs结构只能产生19.80 mA/cm~2的光电流密度.由光电模拟可知,为了获得合理的高光电转换效率,应使少数载流子寿命大于等于1.0×10~(-7 )s,表面复合速率小于等于100 s/cm.     

金融风险管理与物理学家

作为经济物理学的一个重要专题,文章简要介绍了金融风险管理的基本框架和主要内容,包括风险界定、风险来源、风险度量、风险处置等.特别地,展示了物理学在金融风险管理中的可能应用,讨论了物理学家对金融风险管理可能做出的贡献.     

HL-2M装置放电管理平台研制

HL-2M装置放电管理平台的主要功能是为装置运行人员提供一个运行时序系、PLC逻辑保护系统和反馈控制系统的平台.在放电间歇,它在历史数据的基础上预置下一次放电的各种控制波形、配置各个技术子系统的运行模式和运行参数.其基于反射内存的通讯机制主要负责将控制参数和预设波形以有效的、可靠的方式传递到其它子系统中.与各相关子系统...     

Strobovideolaryngoscopy in the management of acute laryngeal trauma

Surgical intervention in the management of acute laryngeal trauma can sometimes pose a difficult decision. The objective of this study is to evaluate the effectiveness of strobovideolaryngoscopy (SVL) in determining the course of management for patients sustaining acute laryngeal trauma. A 20-year retrospective study of patients presenting with acute laryngeal trauma was performed in order to determine if the addition of SVL during the study period changed the management of certain acute laryngeal injuries. Patients sustaining blunt laryngeal trauma evaluated at our institution from 1981 to the present were reviewed. There were 40 patients identified that were grouped by severity according to the Schaefer classification. Analysis included mechanism of injury, clinical presentation, assessment, treatment, and outcome. Group 1 injuries were the most common, with motor vehicle accident (MVA) the most frequent mechanism of injury. Initial assessment included fiberoptic laryngoscopy and computed tomography (CT) imaging in all patients not requiring immediate exploration. SVL was used in 20 patients, with 7 undergoing stroboscopy within 24 hours of presentation. All 7 patients were managed conservatively without surgical intervention or the need to establish an alternative airway. SVL improves the clinical assessment of patients with acute laryngeal injury. This study supports its use and found it to be an important factor in determining the need for surgical intervention. SVL may also shorten the hospital stay in these patients.     

Dispersion management in a harmonically mode-locked fiber soliton laser

Harmonically mode-locked Er-fiber soliton lasers have become a reliable source of high-repetition-rate picosecond pulses in high-speed communications and photonic analog-to-digital conversion systems because of their low-noise, dropout-free operation. We have fabricated such a laser with a strongly dispersion-managed cavity and modeled its operation, and we have found that dispersion management significantly extends the power range over which uninterrupted single-pulse production is attained and dramatically decreases the effects of amplified spontaneous emission on the phase noise of the laser.     

浅谈如何正确实施技术状态管理

文中阐述了技术状态管理的作用和适用范围,介绍了在产品研制过程中应如何开展技术状态管理,总结归纳了新版GJB9001B-2009中针对技术状态管理的一些新要求,并结合实际工作提出了自己的看法.     

Nonlinearity management and diffraction management for the stabilization of two-dimensional spatial solitons

The nonlinear Schrödinger equation which governs the dynamics of two-dimensional spatial solitons in Kerr media with periodically varying diffraction and nonlinearity has been analyzed in this paper using variational approach and numerical studies. Analytical expressions for soliton parameters have been derived using variational analysis. Variational equations and partial differential equation have been simulated numerically. Analytical and numerical studies have shown that nonlinearity management and diffraction management stabilize the pulse against decay or collapse providing undisturbed propagation even for larger energies of the incident beam.     

An integrated toll and ramp control methodology for dynamic freeway congestion management

This paper investigates an integrated freeway traffic management system, which coordinates both dynamic toll pricing and ramp control strategies for the purpose of dynamic freeway congestion management. The proposed integrated dynamic toll-ramp control methodology is built mainly on the principles of stochastic optimal control approaches, involving two developmental procedures. First, through detector configurations and system specification, a discrete-time nonlinear stochastic system is formulated to characterize the time-varying relationships of system states, control variables, and traffic data. Then, by employing the extended Kalman filtering technology, a stochastic optimal control based algorithm is proposed to execute the integrated dynamic toll and ramp control mechanism. With the aid of the Paramics microscopic traffic simulator, numerical studies under various simulated freeway congestion scenarios are conducted. Corresponding numerical results demonstrate the applicability of the proposed methodology in response to diverse freeway traffic congestion phenomena, and its relative advantages in improving both the average travel time and hourly throughputs by 16.4% and 16.5%, respectively.