物理学咬文嚼字之十心有千千结,都付画图中

图像可以帮助表述难以言传之意,所以它一直是物理学以及其他众多学科之重要表现工具.英文物理学文献中常遇到的与图像有关的词汇包括chart,map(mapping),histogram,scratch, sketch,image,plot,inset, painting,drawing,illustration,depict, delineation,profile,graphics,figure, picture,diagram(schematic diagram), graph, photograph, micrograph, cartoon,portrait,以及最近也可以作为稿件部分的film,flash,video,等等.研究者要善于选择最有效的图形表现工具,并要明了这些不同方式间的细微差别.然而,对物理学渐进境界之理解却又要求研究者心中不能着相.此中微义,愿读者诸公参详.     

ICP-AES测定粉末冶金材料中钨、钼等八种元素

用硝酸、高氯酸和氢氟酸溶解样品,在0.025 mol·L-1 EDTA介质中,采用一种标准溶液,用ICP-AES光谱法测定样品溶液中Ni,Cu,V,Mn,W,Mo,Co,Cr的含量。研究了基体和共存元素对分析元素光谱的影响,选择合适的波长,测定了分析结果的精密度,方法的检出限和回收率,结果表明,分析方法有很低的检出限,样品分析结果的相对标准偏差小于1%,加入回收率在98.2%～101.6%,方法准确、可靠、简便、快速,满足生产要求。     

罗马大学附属物理博物馆简介

 意大利首都罗马共有三所国立大学、四所教会大学、二所私立大学。罗马大学(又称罗马第一大学)座落在罗马近郊。它由十个学院(法律,金融与贸易,统计学,文学哲学与考古学,师范,数学物理与自然科学,机械工程,建筑,医疗,药学)、二所附属学校(航空机械,图书档案)、一所国立高等数学研究所、八所附属博物馆(矿业,地质,地理,古典艺术,动物,医学史,古生物学,人类学)组成。     

A theorem for quantum operator correspondence to the solution of the Helmholtz equation

We propose a theorem for the quantum operator that corresponds to the solution of the Helmholtz equation, i.e., V(x1, x2, x3)|x1, x2, x3 x1, x2, x3| d3 x = V(X1, X2, X3) = e-λ2/4: V(X1, X2, X3) :,where V(x1, x2, x3) is the solution to the Helmholtz equation ?2V + λ2V = 0, the symbol : : denotes normal ordering, and X1, X2, X3 are three-dimensional coordinate operators. This helps to derive the normally ordered expansion of Dirac’s radius operator functions. We also discuss the normally ordered expansion of Bessel operator functions.     

Elemental Analysis of Tea Leaves (Camellia Sinensis) and Their Own Soils at Eastern Black Sea Region in Turkey

People consume tea brewed from the leaves of the Camellia sinensis plant for about 50 centuries. Health benefits of the tea have been investigated for about three decades. Especially green tea shows antitoxic and lots of properties with its determined ingredients. Turkey is not only the one of the best consumer and but also good producer of the tea as being 5 th producer all over the world. It grows eastern region of the Turkey and high quality tea is imported and exported. To have quality tea, grooving soils are also crucial. In the current research, Tea leaves and their own grown soils were collected from 20 stations where the most tea producer cities as Trabzon, Rize and Artvin tea fields of the eastern of Black Sea Region in Turkey. The cultivated tea and their own grown soil samples were analysed by using EDXRF Spectrometry. In the soil samples, the elements Mg, Al, Si, P, S, K, Ca, Ti, V, Cr, Mn, Fe, Ni, Cu, Zn, Sr, Ba, Pb on percent level and the elements Mg, Al, Si, P, Cl, K, Ca, Ti, Mn, Fe, Ni, Cu, Zn and Sr in the tea leaves were detected by using SKRAY 3600-EDXRF.and also the obtained data were evaluated with the Kriging interpolation of geostatistical method. Element content were investigated in the soil and tea samples according to the geological situations and also the relation of elemental difference between the tea and the own grown soil. Pb/Zn ratio was also anaysed in the samples.     

科学思想的火花照亮人类智慧的星空

 当暴风雨即将来临的时候,满天阴霾,空气沉闷,正所谓"山雨欲来风满楼,黑云压城城欲摧"。突然,一声霹雳,一道强光划破长空,照得天空和大地无比灿烂。天上的云层,地上的山水,像水洗过一样,尽收眼底。这就是闪电,是云层与云层之间,云层与大地之间由火花放电产生的巨大的电火花。     

《广西物理》投稿须知

1.来稿要求科学性准确,逻辑性强,文字简练,数据可靠,图表清晰,具有创新性或一定新意。每篇文章字数（包括图、表）以不超过6000字为宜。来稿（按顺序）必须包括：题目,作者姓名,作者单位（包括所在地和邮政编码）,中文摘要（不超过300字）,关键词（3～8个）,中图分类号,正文,参考文献。     

物理学咬文嚼字之三十七 溅

碰撞过程(impact,bombardment,collision)难免崩出来一些物质,于是就有了sputter,splash,spatter,spurt等物理上也算常见的词汇,它们同spew,spit,sputum,sprout等同源.     

物理学咬文嚼字之三十三 天有病,人知否?

英文中谈"病"字,有illness,sickness,disease,morbidity,malady,ail ment,pathos等词.Ill,morbid,pathetical,mal(作前缀)和pathological是学术文献中常见的形容词,带有很强的感情色彩.     

2009年全国高考理综（甲、乙卷）物理试题评析

1 总体评价 2009年全国高考(非课改区)理科综合物理试卷共两套,其中:甲卷供云南,贵州,黑龙江,吉林,甘肃,新疆,内蒙古,青海,西藏等省、自治区使用;乙卷供湖北,湖南,河北,河南,山西,陕西,江西,广西等省、自治区使用.     

中物院1～4.2 THz FEL装置波导谐振腔优化设计

针对中物院高功率太赫兹自由电子激光（THz FEL）装置,结合FEL光腔振荡器实验的实际情况,提出了全波导近共心谐振腔设计方案。完成了THz波段波导光腔对光腔品质影响的理论分析和模拟计算,确定了波导设计尺寸为14 mm和22 mm。同时针对最初实验调试过程中无法出光饱和的问题,提出将波导更换为22 mm大尺寸波导的建议,波导更换后很快在2.56 THz获得饱和出光。另外针对实验频段无法覆盖到1～2 THz的问题,我们通过波导内壁粗糙度进行分析判断,提出采用14 mm铜材质的全波导FEL振荡器的设计方案,采用该方案后,实验成功将辐射频段拓展到0.7～4.2 THz,获得饱和输出。     

A method to control the polarization of random terahertz lasing in two-dimensional disordered ruby medium

Terahertz (THz) random lasing is studied numerically for two-dimensional disordered media made of ruby grains with a three-level atomic system. A method via the adjustment of the pumping area to control the polarization of the THz wave is proposed. Computed results reveal that transverse electric THz lasing modes could occur if pumping is supplied on the whole medium, while transverse magnetic THz lasing modes could occur if pumping is appropriately supplied on a partial area of the medium.     

中物院太赫兹自由电子激光装置现状及升级计划

中国工程物理研究院太赫兹自由电子激光装置（CAEP THz FEL, CTFEL）是国内唯一运行的基于超导加速器的高平均功率自由电子激光太赫兹源,具有频率连续在线可调(0.1～4.2 THz)、高峰值功率(＞0.5 MW)、高平均功率(＞10 W)、高重频(54.17 MHz)、短脉冲(～ps)、窄线宽（～2%）、全相干和线性偏振等特点。自2017年出光以来,已稳定运行了四年多,并开展了诸多应用实验研究。为进一步满足用户需求,CTFEL计划升级为一台红外太赫兹自由电子激光装置,电子束能量提升至最大50 MeV,频谱范围拓展至0.1～125 THz,同时,建设材料光谱和生物医学两个实验站。     

半绝缘等离子体波导太赫兹量子级联激光器工艺研究

采用气态源分子束外延设备生长了GaAs/AlGaAs束缚态到连续态跃迁结构的太赫兹（THz）量子级联激光器（QCL）有源区结构,研究了半绝缘等离子体波导THz QCL的器件工艺,采用远红外傅里叶变换光谱仪以及探测器测量了器件的电光特性.器件激射频率为32 THz,10 K下的阈值电流密度为275 A/cm². 关键词： 太赫兹 量子级联激光器 波导 器件工艺     

基于太赫兹量子阱探测器的太赫兹量子级联激光器发射谱研究

采用一个光谱匹配的太赫兹(THz)量子阱探测器(QWP)研究了一激射频率约为41 THz的THz量子级联激光器(QCL)在不同驱动电流下的发射谱,分析了测量得到的发射谱谱型和谱峰位置,根据测量的发射谱估算了太赫兹量子级联激光器发射功率随驱动电流变化的情况,从而得到了THz QCL激射的电流密度范围及其阈值电流密度.文中还研究了THz QWP在不同温度下对THz QCL 激光辐射的响应特性.研究结果表明,THz QWP在表征THz QCL的发射谱方面是一种很好的探测器,并有望成为未来THz通信中的接收装置. 关键词： 太赫兹量子阱探测器 太赫兹量子级联激光器 太赫兹通信 Fourier变换红外光谱     

Material growth and device fabrication of terahertz quantum-cascade laser based on bound-to-continuum structure

The terahertz quantum-cascade laser （THz QCL） based on bound-to-continuum structure is demonstrated. The X-ray diffraction measurement of the material shows a high crystalline quality of the active region. A THz QCL device was fabricated with semi-insulating surface-plasmon waveguide. The test device is lasing at about 3 THz and operating up to 60 K. It shows a single frequency property under different drive currents and temperatures. At 9 K, the maximum output power is greater than 2 mW with a threshold current density of 159 A/cm2.     

Optically pumped GaN/AlGaN quantum well intersubband terahertz laser

We propose an optically pumped nonpolar GaN/AlGaN quantum well (QW) active region design for terahertz (THz) lasing in the wavelength range of 30 μm～ 40 μm and operating at room temperature. The fast longitudinal optical (LO) phonon scattering in GaN/AlGaN QWs is used to depopulate the lower laser state, and more importantly, the large LO phonon energy is utilized to reduce the thermal population of the lasing states at high temperatures. The influences of temperature and pump intensity on gain and electron densities are investigated. Based on our simulations, we predict that with a sufficiently high pump intensity, a room temperature operated THz laser using a nonpolar GaN/AlGaN structure is realizable.     

Circumventing the Manley-Rowe quantum efficiency limit in an optically pumped terahertz quantum-cascade amplifier

Using a microscopic theory based on the Maxwell-semiconductor Bloch equations, we investigate the feasibility of an optically pumped electrically driven terahertz (THz) quantum-cascade laser as a pathway to room-temperature THz generation. In optical conversion schemes the power conversion efficiency is limited by the Manley-Rowe relation. We circumvent this constraint by incorporating an electrical bias in a four level intersubband scheme, thereby allowing coherent recovery of the optical pump energy. The observed THz radiation is generated through both stimulated emission and automatically phase-matched quantum coherence contributions--making the proposed approach both a promising source for THz radiation and a model system for quantum coherence effects such as lasing without inversion and electromagnetically induced transparency.     

Terahertz Quantum Cascade Laser at 3.39THz

We demonstrate the growth of terahertz quantum cascade laser （THz QCL） by gas source molecular beam epitaxy. X-ray diffraction and cross-sectional transmission electron microscopic measurements show the high crystalline quality of the THz QCL active region, From the cross-sectional transmission electron microscopy image, sharp interfaces are observed and the deduced cascade period thickness is consistent with the result of x-ray diffraction. The test device is lasing at 3.39THz and operating up to lOOK in pulsed mode. At IOK, the maximum output power is greater than 1 mW with a threshold current density of 738 A/cm^2.     

2.5THz量子级联激光器的研制

基于束缚态到连续态跃迁有源区能带结构,实现了2.5THz量子级联激光器的连续波工作。激光器的输出频率随电流可在2.45~2.47THz之间可调,在连续波工作模式下的最高输出功率大于6.0mW,最高连续波工作温度为60K,阈值电流密度为120A/cm2,经Si透镜整形后的输出光斑为高斯分布。