高压对大块（PrNd）xAl0．6Nb0．5Cu0．15B1．05Fe97．7-x合金微观结构和性能的影响冰

经配料、熔炼、制粉、成型和烧结后制备了（PrNd）xAl0．6Nb0．5Cu0．15B1．05Fe97．7-x（质量百分比）合金,将该合金分别采用1．5GPa和3．0GPa的压强进行压制,研究了此高压对其显微结构和磁性能的影响．分析发现,该块状合金承受的压强越高,其外观和微观结构破坏越严重,抗弯强度也会降低,但高温抗氧化性能却有一定程度的提高．与没有经过高压处理的磁体相比,经过1．5GPa和3．0GPa高压的样品最大磁能积分别提高了7．69kJ．m^-1和0．94kJ．m^-1,剩余磁通密度分别提高了0．02T和0．01L内禀矫顽力分别提高了20．06kA．m-1和30．33kA．m^-1．结果表明,高压对块状NdFeB烧结磁体的显微结构和力学性能及磁性能均有一定的影响．     

卡文迪什实验室今昔

系统地介绍和分析了Ｊ．Ｃ．Ｍａｘｗｅｌｌ着手建立卡文迪什实验室的背景、宗旨、方针和方法；概要地分析与说明了 Ｊ．Ｊ．Ｔｈｏｍｓｏｎ和Ｅ．Ｒｕｔｈｅｒｆｏｒｄ怎样将该实验室建设成主要世界科研中心，Ｎ．Ｆ．Ｍｏｔｔ和Ａ．Ｂ．Ｐｉｐｐａｒｄ为什么发展和部分地变革它的传统并将其主要研究方向改变为凝聚态物理，以及在经济衰退和人才流失情况下采取哪些措施； 介绍了实验室规模的发展和几位卡文迪什教授的风格．     

非掺杂半绝缘LECGaAs的光电流谱

研究了非掺杂半绝缘ＬＥＣＧａＡｓ的非本征室温（３００Ｋ）光电流谱,在０．４－０．７０９ｅＶ范围发现了一个光响应响应宽带Ｍ１。Ｍ１带在０．４６、０．４９、０．５６、０．６５和０．６９ｅＶ处出现五个峰,其中０．４６、０．４９、０．５６和０．６９ｅＶ峰的起始阈值分别为０．４４、０．４７、０．５１和０．６７ｅＶ。本文讨论了Ｍ１带的起源,提出了０．４４、０．４７和０．５１ｅＶ光电阈值与铜受主,ＥＬ３和氧施主     

A^208Pb的超子分布半径和中子星结构

从相对论平均场理论出发，考虑核子、超子和介子自由度，研究了A^208Pb的超子分布半径与中子星的性质以及它们之间的关系。计算发现当超子的耦合常数比值由0．3增大到1时，对NLSH和NL3参数组，超核的超子分布半径分别由3．905和3．849fm增大到4．346和4．230fm，而中子星的最大质量分别由1．516和1．429M增大到2．776和2．744M，质量为1．4M的中子星半径分别由13．13和12．79km增大到13．24和13．29km。即中子星的最大质量和半径随超子分布半径增大而增加。这样只要从实验上确定A^208Pb的超子分布半径，就可以得到中子星结构的信息。     

稀土金属表面的振动弛豫

用ＬＥＥＤ谱，研究了稀土金属表面的振动弛豫。结果表示出，对Ｓｃ｛０００１｝，原子层间距：ｄ１＝２．４１３±０．００１Ａ（收缩８．６％±０．００１Ａ）和ｄ２＝２．６８±０．０２Ａ（膨胀１．５％±０．０２Ａ）。对Ｇｄ｛０００１｝，原子层间距：ｄ１＝２．８０±０．０４Ａ（收缩３．１％±０．０４Ａ）和ｄ２＝２．９６±０．０３Ａ（膨胀２．４％±０．０３Ａ）。对Ｔｂ｛０００１｝，原子层间距：ｄ１＝２．７５±０．０３Ａ（收缩３．３％±０．０３Ａ），ｄ２＝２．８５±０．０１Ａ（膨胀０．１８％±０．０１Ａ）和ｄ３＝２．９８±０．０３Ａ（膨胀４．７％±０．０３Ａ）。对Ｔｂ｛１１２０｝，原子层间距：ｄ１＝１．６５±０．０２Ａ（收缩８．３％±０．０２Ａ）和ｄ２＝１．８０±０．０４Ａ（膨胀０．０６％±０．０４Ａ）     

国内声学文献分类索引

（声学分类：43．10总类;43．15标准;43．20一般线性声学;43．25非线性声学;强声学;43．28航空声学;大气声学243．30水声学;43．35超声学,量子声学及声的物理效应;43．40机械振动和冲击243．45统计声学;43．50噪声：影响和控制;43．55建筑声学;43．60声信号处...     

原子吸收法测定人精子中锌和铜含量的研究

本文采用石墨炉原子吸收法，以ＮＨ４ＮＯ３和Ｍｇ（ＮＯ３）２混合剂作基体改进剂，测定了人精子中微量元素铜和锌。基方法的特征质量分别为１０．００ｐｇＣｕ／０．００４４Ａ．Ｓ．，９．８０ＰｇＺ／０．００４Ａ．Ｓ；平均加收率为９７．４２％，锌为１０１．９１％，铜和锌的精密度分别是４．１％和４．０３％。     

Ba0.97Ce0.8Ho0.2O3-α陶瓷的离子导电性及其燃料电池性能

用高温固相反应法制备了Ba0．97Ce0．8Ho0．2O3-α钙钛矿型氧化物固溶体,粉末X射线衍射表明,该固溶体为单相．研究了样品在高温下的离子导电性以及氢-空气燃料电池性能,并与BaCe0．8Ho0．2O3-α进行比较．结果表明,在潮湿氢气中、600-1000℃,BaCe0．8Ho0．2O3-α几乎表现为纯的质子导电性;在600-900℃时质子迁移数为1;在1000℃时质子的迁移数为0．99,与BaCe0．8Ho0．2O3-α相同;在600-700℃时Ba0．97Ce0．8Ho0．2O3-α也显示了纯的质子导电性,其质子迁移数为1;但在800-1000℃时Ba0．97Ce0．8Ho0．2O3-α的质子迁移数为0．99-0．96,质子导电性略低于BaCe0．8Ho0．2O3-α．在潮湿的空气中、600-1000℃下,这两个样品均显示了较低的质子和氧离子导电性,Ba0．97Ce0．8Ho0．2O3-α的质子和氧离子的迁移数分别为0．01- 0．11、0．30-0．31,BaCe0．8Ho0．2O3-α的质子和氧离子迁移数则分别为0．01-0．09、0．27-0．33．在潮湿氢气和空气中,Ba0．97Ce0．8Ho0．2O3-α的电导率均高于BaCe0．8Ho0．2O3-α．以Ba0．97Ce0．8Ho0．2O3-α为固体电解质的氢-空气燃料电池的性能高于BaCe0．8Ho0．2O3-α,在1000℃时,前者燃料电池的最大电流密度和功率密度分别为465 mA／cm2和112 mW／cm2．     

双掺杂La0.67+1.33xSr0.33-1.33xMn1-xMgxO3体系的磁性和输运行为

用标准的固相反应法制备了双掺杂La0.67 1．33xSr0．33-1．33xMn1-xMgxO3(x=0．00,0．05,0．10,0．15,0．20,0．25)多晶样品,研究了它们的磁性和输运行为。对x=0．10和0．15,在温度高于Tc^cnset时出现相分离;对x=0．20和0．25,在低温区出现反铁磁行为。低掺杂样品ρ-T关系存在金属．绝缘体相变,高掺杂样品在测量温区内仅显示绝缘体行为。这些奇异现象用M-H关系、ESR曲线和拉曼光谱给予了很好的解释。     

国内声学文献分类索引

（声学分类：４３．１０总类;４３．１５标准;４３．２０一般线性声学;４３．２５非线性声学;强声学;４３．２８航空声学;大气声学;４３．３０水声学;４３．３５８声学,量子声学及声的物理效应; ４３．４０机械振动和冲击; ４３．４５统计声学; ４３．５０噪声;影响和控制; ４３．５５建筑声学;４３．６０声信号处理,声全息技术;４３．６３生理声学;４３．６６心理声学; ４３．７０语言通信;４３．７５音乐与乐器Ｓ ４３．８０生物声学;４３．８５声学测量与仪器; ４３．８８换能器;声音的产生与复制设备．） ４３．…     

关于"太阳在银河系中所受引力与到银心距离r的关系"的讨论

讨论了银道面内的引力场强分布和太阳在银河系中所受引力与到银心距离r的关系，指出引力场强g并不是与r的平方成反比，这是由于银河系的大小和形状不能忽略造成的．强调了万有引力定律的适用条件．     

On the predictability of the positions of the convergence zones in the ocean

The disagreement between the experimental and calculated positions of the first convergence zone are known from many publications. The most probable cause for such a disagreement, namely, the incorrect specification of the input data for the calculations, is considered. The lack of simultaneity between the hydrological surveys of the region and the acoustic experiments is emphasized. The experimental data obtained by the author in five ocean regions are presented. These data characterize the diurnal variability of the distance from the source to the nearest boundary of the convergence zone. The relations proposed by different researchers for calculating the sound speed from the temperature, salinity, and hydrostatic pressure are analyzed. It is shown that these relations lead to a substantial difference in the estimated depth dependence of the hydrostatic gradient of the sound speed. The position of the first convergence zone is calculated for the propagation conditions determined by vertical temperature and salinity profiles with the subsequent recalculation of these profiles into sound speed profiles by using eight different formulas known from the literature. It is shown that different formulas lead to different values of the distance to the first zone; this difference is substantially greater than that between the calculations and experiment. The necessity of improving the recalculation relations in view of the experimental data on sound propagation in natural oceanic waveguides, including the data on the actual positions of the convergence zones, is emphasized.     

On the calculation of the bremsstrahlung in the region of the plasma frequency

On the basis of the classical theory of radiation produced in incomplete Coulomb interaction, a formula is derived for the coefficient of the bremsstrahlung of fully ionized plasma. In the region of rectilinear approximation a comparison is made with the results of the quantum formula derived from the Born approximation. Furthermore, the influence of dispersion upon the emission coefficient is taken into account; some relations for the region of dispersion are given.     

Dependence of the Intensity of the Spectral Lines and the Composition of the Sample and the Plasma Parameters of the Unipolar Arc

The investigation was made of the dependence of the intensity of Tl, Ga, Mo, Mg, Mn, Sn, Bi, Ni, Zn, Pt and Au spectral lines and the plasma parameters (temperature T, electron concentration n_e, degree of 6 ionnization α) from concentration of lithium additive.     

Extracting the wavefunction of the LSP at the LHC

We consider associated production of squarks and gluinos with the lightest supersymmetric particle (LSP), or states nearly degenerate in mass with it. Though sub-dominant to pair production of color SU(3)-charged superpartners, these processes are directly sensitive to the wavefunction composition of the lightest neutralinos. Exploiting event-shape variables - including some introduced here for the first time - we are able to identify the composition of the LSP by selecting events involving a single high-pT jet recoiling against missing transverse energy. We illustrate the proposed technique on a set of benchmark cases and propose methods for applying these results in more realistic experimental environments.     

Set the controls for the heart of the Sun

In this paper we describe experiments conducted with high-power lasers that are attempting to replicate, for a very short time and in miniature, conditions found in the Sun. Experiments to date have reached conditions in the outer part of the Sun. To reach the Sun's centre requires compression of material to very much greater than solid density and heating to over ten million degrees. To achieve this, a new class of experiments and a new generation of high-power lasers are required.     

On the Question of the Source of the Apokamp

Technical Physics - The object of this work is the apokamp—a new type of plasma jet, which is formed from a bright offshoot emerging at the bending point of a channel of a high-voltage...