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1.
在相对论σ–ω模型的单圈图近似下,详细推导了核物质的能量密度和压强密度表达式,数值计算了核物质的结合能和压强随核密度的变化,并分别在热力学和流体力学的理论框架下,计算了核物质的压强密度,结果表明这两种方法得到的压强密度相同.  相似文献   

2.
韦晓娜  杨波  陆侃  刘鹏飞 《光子学报》2011,(10):1599-1602
利用激光二极管作为光源,对红外触摸屏的原始结构加以改进,用激光和导光管的组合来取代单排发光二极管,设计了一种具有微结构的导光管.导光管采用PMMA材料,其折射率n2=1.49,在全反射的条件下,导光管微结构的几何参量通过解方程的方式获取.分别建立了导光管的光学和机械模型,建模结果表明,本文所提出的触摸屏的设计方法能够改...  相似文献   

3.
 迈克尔·法拉第是19世纪伟大的物理学家,他对物理学最卓越的贡献就是通过实验发现了电磁感应定律。当时法拉第受德国古典哲学中辩证思想的影响,认为电、磁、光、热之间是相互联系的。1820年奥斯特发现了电流对磁针的作用,法拉第敏锐地认识到了它的重要性。  相似文献   

4.
周开亿 《光谱实验室》2007,24(1):179-181
在剑桥大学的蒙德实验实门口,竖有三座引人注目的雕像:一个是出资兴建这座实验室的蒙德先生,另一个是农民模样的人,余下一个是只鳄鱼。那个农民模样的人就是著名物理学家卢瑟福,而那只鳄鱼就是为体现卢瑟福勇往直前的坚毅性格而雕塑的。“锷鱼”是俄国物理学家卡皮察为卢瑟福起的一个绰号。他说:“在俄国,鳄鱼是一家之父的象征,令人赞赏和敬畏,因为它有直挺挺的脖子,无法回头。  相似文献   

5.
基于遗传算法的减反射膜的优化设计   总被引:2,自引:1,他引:1  
吴素勇  龙兴武 《应用光学》2008,29(4):542-547
为了研究膜系设计领域内的全局性优化方法,提出了基于遗传算法的膜系设计方法。编制了用遗传算法进行膜系设计的通用程序,并在各种类型的减反射膜设计中取得了成功。结果表明:基于遗传算法得到的减反射膜具有与近期发表的膜系结果相一致或更好的光谱性能和全局性。同时在应用遗传算法进行膜系设计时,不需要给定初始膜系,可以设定膜层厚度边界和膜层数,这对于设计和镀制有现实意义的光学薄膜极为有利,并且只要改变目标反射率就能推广到其他膜系的设计中,具有良好的可移植性。  相似文献   

6.
为了研究弱冲击条件下氩气的辐射特性,从二级轻气炮发射的89 W飞片以2.00 km/s的速度撞击封装有常态下氩气的LY12铝靶,用六通道瞬态高温计和示波器记录到受一次冲击压缩的氩气的光辐射信号随时间的变化规律:从405 nm到700 nm的5个通道信号为直线段,800 nm通道的信号为指数曲线段,并测量出相应的冲击波速度为4.10±0.09 k m/s.实验表明,冲击压缩的氩气对可见光的吸收系数较小,气体的光学厚度沿长波方向从光学薄向光学厚转变.二次冲击压缩氩气的辐射信号上升前沿的时间分辨光谱用OMA系统记录,并观察到450 nm附近有较强的发射光谱带,但没有观察到明显的线状光谱.通过冲击波后参数和氩气电离度的理论计算,解释了冲击压缩下氩气的发射光谱特性.  相似文献   

7.
黄卫良 《物理实验》2006,26(2):30-31
针对现行教材的内容制作了光的偏振演示仪.该演示仪既可以真实的演示光的偏振现象,又可以通过在形成驻波的弦上放置狭缝,模拟演示光的偏振现象,且驻波的振动频率连续可调.  相似文献   

8.
文章从实验物理教学的范畴和性质出发,比较中外实验教学的差异,结合当前存在的问题,探讨理想的实验物理教学模式.提出实验物理教学应当以学生为中心,鼓励学生的自主创新精神和师生密切互动;发展实验教学中心应当以质量为重点,而不是盲目追求数量;努力把实验物理教学中心建设成为教学的平台、探索的基地、求知的乐园.  相似文献   

9.
 我们知道,科学和艺术都要以各自的同构方式,去反映大千世界无数现象背后的两种秩序:精确的、严格的秩序以及混沌、奔放的秩序。从而在形成各具特色的文化领域的同时,也使科学和艺术间的融洽达到了维妙维肖的程度,其中诗的物理与物理的诗就是科学和文艺联姻的产儿。  相似文献   

10.
定义时间和钟的同步。设计钟的同步的实现方法。指出相对论有关时间问题的错误。  相似文献   

11.
本文研究了全浓度ErLaP5O14非晶在波长λ为649.0nm脉冲染料激光激发下的上转换发光现象,并对其进行了简要的分析。  相似文献   

12.
Poly(styrene-b-(ethylene-co-butylene)-b-styrene) (SEBS) copolymer biomedical elastomer was covalently grafted with poly(ethylene glycol) methyl ether methacrylate (PEGMA) via a photo-initiated graft polymerization technique. The surface graft polymerization of SEBS with PEGMA was verified by ATR-FTIR and XPS. Effect of graft polymerization parameters, i.e., monomer concentration, UV irradiation time and initiator concentration on the grafting density was investigated. Comparing with the virgin SEBS film, the PEGMA-modified SEBS film presented an enhanced wettability and a larger surface energy. Besides, the surface grafting of PEGMA imparted excellent anti-platelet adhesion and anti-protein adsorption to the SEBS surface.  相似文献   

13.
The solvatochromic behaviour of bis-(2,2′-bipyridyl)-biscyanoiron (II) and 2,2′- bipyridyltetracyanoiron (II) in 2-ethyl-2-(hydroxymethyl)-1,3-propanediol has been established. The significance and sensitivities of the solvatochromic shifts of these charge-transfer bands are outlined for the two iron complexes above.  相似文献   

14.
A range of coprecipitated Fe(III)-Me(II) (Me(II) = Ni, Cu) hydroxides and of the products of their thermolysis have been investigated by the IR spectroscopy method. The basic absorption bands has been assigned, and the chemistry of the process of formation of coprecipitated hydroxides has been discussed from the standpoint of generation of heteronuclear hydrococomplexes.  相似文献   

15.
Poly(ferrocenylsilanes) (PFS) belong to the class of redox responsive organometallic polymers. Atomic force microscopy (AFM)-based single molecule force spectroscopy (SMFS) was used earlier to study single chain PFS response and redox energy driven single chain PFS molecular motors. Here we present further AFM investigations of force interactions between tip and a grafted PFS surface under potential control in electrochemical redox cycles. Typical tip-Au interaction is considered as reference in the force measurements. First the electrostatic component in the diffused double layer (DL) in NaClO4 electrolyte environment was considered for a “grafted to” PFS, which dominated the interplay between the tip and sample surface. The DL forces can also hinder the physisorption of PFS chain onto the tip when the voltage was applied at −0.1 V. On the other hand, if the tip contacted the PFS surface prior to the electrochemical process, physisorption of PFS chains governed the overall interaction regardless of subsequently applied surface potential. In addition, prolonged contact time, tc, may also contribute to the stability of tip-PFS bridging and detection of electrostatic forces between the tip-PFS interface. The results showed that tip-substrate interaction forces without PFS grafts have negligibly small force contributions under similar, electrochemically controlled, conditions used in single PFS chain based molecular motors.  相似文献   

16.
New toughened poly(trimethylene terephthalate) (PTT) materials were obtained by melt blending with maleic anhydride grafted poly(ethylene-octene) (POEg). Rheological properties, mechanical properties, and morphological characteristics of PTT/POEg blends at four different compositions—95/5, 90/10, 80/20, and 70/30—were studied. The melt viscosity of the blends shows a linear decrease on increasing the POEg content. The addition of rubbery POEg to the PTT matrix increases the impact strength, while tensile properties decrease. Scanning electron microscopy (SEM) displayed a very good dispersion of POEg particles in the PTT matrix. Differential scanning colorimetry (DSC) experiments showed that for all samples the melting point was almost constant and the crystallinity did not show obvious differences. SEM results showed shear yielding of the PTT matrix was the major toughening mechanism.  相似文献   

17.
应用第一性原理对CO分子在Co(0001)表面( squar3× squar3)R30°−CO吸附结构进行不同形式的密度泛函计算研究. 结果表明:吸附能修正前,仅RPBE泛函预测CO顶位吸附;而修正后PW91、PBE和PKZB泛函结果也表明CO分子Top顶位吸附最稳定,与实验结果一致.对于吸附几何结构、吸附前后体系功函、C-O伸缩振动频率和CO分子态密度分布,所有泛函给出一致的结果,且与已有实验结果符合.  相似文献   

18.
We present the results from investigations of the nonlinear refractive index and nonlinear absorption coefficient of tris(acetylacetonato)manganese(III) solution, using Z-scan technique with a low-power continuous-wave laser at 514 nm. We demonstrate that the light-induced nonlinear refractive index variation leads to strong self-focusing and self-defocusing. A pump and probe technique was used to investigate the cause of nonlinearity. Furthermore, the nonlinear absorption effect was utilized to demonstrate all optical switching.  相似文献   

19.
张婷  殷江  丁玲红  张伟风 《中国物理 B》2013,22(11):117801-117801
Stoichiometric Ba(Mn_xTi_(1-x)O_3) (BMT)thin films with various values of x were deposited on Si(111)substrates by the sol-gel technique.The influence of Mn content on the optical properties was studied by spectroscopic ellipsometry(SE)in the UV–Vis–NIR region.By fitting the measured ellipsometric parameter(Ψand)with a four-phase model(air/BMT+voids/BMT/Si(111)),the key optical constants of the thin films have been obtained.It was found that the refractive index n and the extinction coefficient k increase with increasing Mn content due to the increase in the packing density.Furthermore,a strong dependence of the optical band gap Egon Mn/Ti ratios in the deposited films was observed,and it was inferred that the energy level of conduction bands decreases with increasing Mn content.  相似文献   

20.
三螺旋DNA分子poly(dT)·poly(dA)·poly(dT)的构型和振动谱   总被引:4,自引:0,他引:4  
我们计算了poly(dT)·poly(dA)·poly(dT)的Howard模型的原子笛卡尔坐标,并利用晶格动力学方法对模型进行了简正分析。结果发现其0 P 0对称振动模式位于804cm-1,这和810cm-1附近没有拉曼和红外谱线的实验结果不符。在800~1000cm-1的范围内只有四个振动模式,明显少于拉曼和红外光谱在该范围内的谱线数目。所以我们认为Howard模型需要进一步地完善和修正,poly(dT)·poly(dA)·poly(dT)必须具有三条不完全一致的脊骨  相似文献   

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