勒纳（Lenard，Philipp Eduard Anton von 1862-1947）匈牙利-德国物理学家（Physicist，Hungary-Germany）

勒纳曾在本生和赫姆霍兹的指导下学习，1886年获海德堡大学的博士学位，后来任物理学教授，1931年退休。勒纳在十几岁时读到克鲁克斯的阴极射线的论文，对此发生兴趣。赫兹发现，阴极射线能够穿透薄金属片，而他当时的助手勒纳设计了一种有薄铝窗的阴极射线管，可使阴极射线从中穿过而进入空气（这种射入空气的阴极射线一度被称为勒纳射线）。     

太赫兹大气传输特性实验研究

太赫兹在高速率通信、高分辨力雷达等方面具有广阔的应用前景,而对太赫兹辐射的大气传输特性及其规律进行系统的理论与实验研究则是发展利用该频谱资源的基础条件。对大气作用于太赫兹频段电磁辐射的吸收衰减进行了实验测试研究。通过双光路的差分系统设计,尽可能地减小太赫兹辐射源输出功率不稳定性所产生的系统误差,完成大气模拟环境下太赫兹波段多个频点传输的功率变化测定,以探索大气环境对不同频段THz波衰减的规律性;同时,建立太赫兹大气传输特性动态数据库对海量大气环境数据进行有效地分析,为实验数据处理及理论研究提供支持。收稿日期:; 修订日期:     

邮票上的物理学史B37——X射线的发现

前两节介绍了上一次世纪之交时经典物理学理论和已知实验事实的矛盾.这些实验事实才刚刚触及高速和微观领域.19世纪末，在实验上还有三大发现，即X射线、电子和放射性，这些发现进一步打开了微观世界的大门.这三项发现都直接或间接与阴极射线的研究有关.阴极射线是当时的热门研究题目，早在19世纪30年代，法拉第就发现了稀薄气体放电中的辉光现象.随着真空技术不断进步和真空度不断提高，物理学家又发现了阴极射线.它产生于高真空放电管的阴极，撞击对面的管壁，使之发荧光.用现在的话来说，所谓阴极射线，就是电场从阴极拉出来的电子流.电子的发现当然直接与阴极射线有关，X射线是伦琴在研究阴极射线时发现的，而放射性则是贝克勒尔研究X射线时发现的.     

邮票上的物理学史(37)——X射线的发现

前两节介绍了上一次世纪之交时经典物理学理论和已知实验事实的矛盾 .这些实验事实才刚刚触及高速和微观领域 .1 9世纪末 ,在实验上还有三大发现 ,即Ｘ射线、电子和放射性 ,这些发现进一步打开了微观世界的大门 .这三项发现都直接或间接与阴极射线的研究有关 .阴极射线是当时的热门研究题目 ,早在 1 9世纪 3 0年代 ,法拉第就发现了稀薄气体放电中的辉光现象 .随着真空技术不断进步和真空度不断提高 ,物理学家又发现了阴极射线 .它产生于高真空放电管的阴极 ,撞击对面的管壁 ,使之发荧光 .用现在的话来说 ,所谓阴极射线 ,就是电场从阴极拉出…     

太赫兹波在非磁化等离子体中的传输特性研究

本文对太赫兹波在非磁化等离子体中的传输特性进行了理论和实验研究,得到了非磁化等离子体中太赫兹波传输特性随太赫兹波频率、等离子体密度、碰撞频率和厚度的变化规律．发现了一些新的现象：随着太赫兹波频率增加,反射率曲线出现周期性振荡,振荡周期为0．03THz．随着太赫兹波频率增加,振荡幅度增加：随着等离子体密度增加,振荡幅度减小;随着等离子体碰撞频率增加,振荡幅度增加．反射率曲线出现振荡的原因是电磁波在z=0和z=-d界面处的多次反射所致．以激波管为实验平台进行了0．22THz太赫兹波在等离子体中传输特性的实验研究,实验结果和理论结果符合较好．理论和实验结果均表明,采用太赫兹来实现地面与飞行器之间的通信互联是解决黑障问题的可选途径之一．     

布料的太赫兹波透射特性研究

为获得太赫兹波对常见衣物布料的穿透特性,基于布料的物理结构以及太赫兹波传输的影响因素,建立了常见布料的太赫兹波传输模型,计算获得了不同相对湿度条件下典型太赫兹波长对布料的透过率。随后,利用太赫兹时域光谱系统对棉质布料样品进行透射实验测试,获得了布料在0.1~2 THz范围内不同相对湿度条件下的透过率。通过理论计算结果与实验测试结果的对比分析,验证了该传输模型的有效性,获得了太赫兹波对常见棉质布料的穿透特性。此外,在30%相对湿度条件下,实验研究了多层棉质布料的太赫兹透射特性。研究结果表明,在可见光波段"不透明"的衣物布料,利用太赫兹波可实现良好的"透视",但其对布料的穿透特性一定程度上受到环境相对湿度的影响,该研究对于衣物内隐藏危险物品的快速检测具有重要意义。     

暗态多极赝局域等离子模式的太赫兹涡旋光激发

理论分析和实验验证了太赫兹涡旋光与带有周期性亚波长金属褶皱圆盘中暗态多极赝局域等离子模式的相互作用.研究结果表明,携带不同轨道角动量和自旋角动量的太赫兹涡旋光可以决定最终激发出的太赫兹暗态多极等离子模式,此结果和光频段的理论分析一致.利用太赫兹近场扫描方法对涡旋光的自旋和轨道角动量与暗态多极等离子模式的对应关系进行了实验论证,实验结果与理论仿真符合较好.研究成果将对太赫兹物理、等离子体以及成像领域研究起到一定的促进作用.     

太赫兹时域光谱技术在玉米种子鉴定中的实验研究

用太赫兹时域光谱技术对农大108和郑单958两种玉米种子的胚和DNA进行了探测。给出了种子胚在太赫兹波段不同时的折射率曲线。对比了两种玉米种子胚吸收光谱的异同。为深化实验,对两种玉米种子DNA的吸收光谱进行了对比,并进行了相关讨论。该研究为将太赫兹时域光谱技术应用于玉米种子的鉴定打下了实验基础。     

也论电磁波的预言及其发现过程

文章根据麦克斯韦的著作和赫兹的《综合文集》、《电波》和《回忆、书信和日记》以及相关文献，对麦克斯韦预言电磁波的问题和赫兹实验发现电磁波的过程进行了仔细考察，指出麦克斯韦没有明确预言电磁波的存在，麦克斯韦的理论不是赫兹电磁学实验研究的直接指导思想．文章认为亥姆霍兹为普鲁士科学院所提出的1879年悬赏课题对赫兹发现电磁波起到了直接的引导作用，而电磁波的发现则主要归因于赫兹精湛的实验技能和敏锐的观察力．     

太赫兹波光谱特性分析

目前太赫兹技术的研究主要集中在它的产生、探测机理研究上。由于太赫兹波处于微波和可见光之间的频率范围,已有的微波和光波理论是否能适用于太赫兹波或者具有某些共同的特性仍需实验验证。通过实验分析验证了太赫兹波在空气介质中在垂直于传播方向的平面内场振幅是服从高斯函数分布的,测量给出了太赫兹波的能量分布图。根据测试数据推导出太赫兹波在空气介质中能量衰减公式,利用法布里-珀罗(F-P)干涉仪原理设计出太赫兹波长仪,对美国Corehent公司SIFIR-50THz太赫兹激光器发射的1～3THz波长进行了测量。讨论分析了远场发射角、光束入射角度、机械振动、温度波动和折射率n波动等相关因素对测量精度的影响。     

Paul Villard's discovery of gamma rays – A centenary

It is shown how Paul Villard's chemical interests guided him in his studies of cathode rays, X rays and radium rays. His experiments in radioactivity led to the unexpected discovery of gamma rays in 1900.     

On the cathodoluminescence of thin films

An analysis is given of the voltage dependence of the cathodoluminescence of thin luminescent films, taking into consideration the surface recombination and diffusion processes of induced carriers. In the analysis Young's laws were used for the dissipation and range of incident cathode rays. The smooth maximum of experimental voltage response curves can be explained by strong surface recombination on the support.The author wishes to express his sincere thanks to Mr. Gy. Katona for his help in the computations.     

Eugen von Gothard and His X-Ray Experiments

Eugen von Gothard (1857–1909) made significant contributions to astrophysics and founded the Astrophysical Observatory in Herény, Hungary, in 1881. He also was a gifted instrument maker who designed and produced the apparatus and equipment he needed to carry out his researches, which enabled him to respond immediately to Wilhelm Conrad Röntgen’s astonishing discovery of X rays. Von Gothard took his first X-ray photograph on January 23, 1896, thus inaugurating his first series of experiments, which ended on May 26, 1896. He carried out a second series of experiments on June 21–22, 1905, four years before his premature death at age 51.     

1912: a titanic year for mass spectrometry

The 1912 sinking of the Titanic continues to capture the imagination and fascination of the general public. The year coincides with the birth of mass spectrometry that began with the cathode ray experiments performed by Joseph John (J. J.) Thomson in Cambridge. Modifications made to Thomson's cathode ray apparatus by Francis William Aston, resulted in an increase in the brightness of the positive rays that aided their detection. This led to the discovery of heavy isotopes for many of the chemical elements in the ensuing decades. As the discovery of (22) Ne was reported in 1913, another of Thomson's students was taking part in an expedition to help save future ocean liners from the fate of the Titanic. Geoffrey Ingram Taylor took part in the first ice patrol of the North Atlantic in 1913 aboard the SS Scotia to investigate the formation and position of icebergs. This article, 100?years on, describes Taylor's work and its impact on safe ocean passage across the Atlantic. Copyright ? 2012 John Wiley & Sons, Ltd.     

X-ray radiography of aluminum cathodes eroded in high-current vacuum arcs

The aim of the study presented in this paper was to characterize quantitatively the erosion of aluminum cathodes in high-current vacuum arcs. The experimental setup comprised two current generators. The first one, capable of generating a current of amplitude up to 350 kA, was used to produce a plasma jet, that is, the object to be investigated. The second generator was used to produce a source of probe radiation for imaging the object under investigation in soft x rays of energy ?ν ≈ 0.5–3 keV. The findings of the study are based on experimental data obtained by electrophysical and radiographic methods. It has been shown that the cathode erosion rate in a high-current vacuum arc is a function of the charge passed through the cathode.     

Henri Victor Regnault: Experimentalist of the Science of Heat

Henri Victor Regnault (1810–1878) was one of the most famous French experimental scientists of the nineteenth century. After studying and carrying out research at the école Polytechnique and the école des Mines in Paris, he was elected to the Paris Académie des Sciences in 1840 and was appointed Professor of Experimental Physics at the Collège de France in 1841. His initial researches were in chemistry, but his careful experimental investigations of the law of the specific heat of solids that Pierre Louis Dulong (1785–1838) and Alexis Thérèse Petit (1791–1820) proposed in 1818 opened the door to his transition to physics and to his pioneering experimental researches on various thermodynamic properties of liquids and gases. I focus particularly on his investigations on the expansion, compressibility, vapor pressure, and speed of sound in gases. He also made important contributions to the new art of photography and to the ceramic industry as director of the Sèvres factory, at a time when his personal life was filled with tragedy. While his experimental work was acclaimed by his contemporaries, it has been largely neglected by scientists and historians today.     

强激光束与空腔靶相互作用实验研究

1.06μm波长的强激光束辐照Au材料制作的空腔靶,采用目前国内最先进的诊断设备。对腔内高温等离子体现象演变规律进行了实验观察,获得了反射激光、能量吸收、X光转换、亚千X光能谱及时空特性、辐射温度、超热电子等重要物理信息,并就实验结果作了必要的分析和讨论     

贝克勒尔对放射性的发现及研究

简述了贝克勒尔的生平,回顾了贝克勒尔在发现X射线后,进一步发现铀盐能使照相底版感光,并能使带电的验电器放电,发现铀的放射性的过程及其后续的研究,分析了他如何抓住机遇,充分利用有利条件,坚持不懈、严谨缜密地进行研究和勇于探索的精神.     

Synergistic effects of neutron and gamma ray irradiation of commercial CHMOS microcontroller

This paper presents the experimental results of a combined irradiation environment of neutron and gamma rays on 80C196KC20, which is a 16-bit high performance member of the MCS96 microcontroller family. The electrical and functional tests were made in three irradiation environments: neutron, gamma rays, combined irradiation of neutron and gamma rays. The experimental results show that the neutron irradiation can affect the total ionizing dose behaviour. Compared with the single radiation environment, the microcontroller exhibits considerably more severe degradation in neutron and gamma ray synergistic irradiation. This phenomenon may cause a significant hardness assurance problem.