Nonequilibrium thermodynamics and fluctuation relations for small systems

In this review, we give a retrospect of the recent progress in nonequilibrium statistical mechanics and thermodynamics in small dynamical systems. For systems with only a few number of particles, fluctuations and nonlinearity become significant and contribute to the nonequilibrium behaviors of the systems, hence the statistical properties and thermodynamics should be carefully studied. We review recent developments of this topic by starting from the Gallavotti–Cohen fluctuation theorem, and then to the Evans–Searles transient fluctuation theorem, Jarzynski free-energy equality, and the Crooks fluctuation relation. We also investigate the nonequilibrium free energy theorem for trajectories involving changes of the heat bath temperature and propose a generalized free-energy relation. It should be noticed that the non-Markovian property of the heat bath may lead to the violation of the free-energy relation.     

网络化《大学物理》教学体系的建设和应用

文章介绍了基于网络技术的《大学物理》教学体系的建设和应用，该体系以精品课程建设为依托，建设《大学物理》课程网络资源，在正常教学中引入网络化联班教学模式．实现主讲教室和其他多媒体副教室之间的音视频及教学课件传输，并对信号进行实时采集和编辑处理，形成可供网络传输的流媒体课件．在保证教学质量的前提下，该网络化教学体系有效地扩大了教学规模，实现了教学手段的优化和教学资源共享．     

放电参数对毛细管放电泵浦的软X射线激光的影响

 以哈尔滨工业大学可调谐激光技术国家重点实验室中的Marx发生器的放电脉冲波形为基础,理论上模拟计算了在不同放电参数下充氩气的毛细管放电产生的等离子体状态和类氖氩离子3p_3s跃迁线的增益系数的时空演变过程。中心模型中,选取内径为3.1 mm 的陶瓷毛细管并充入初始密度为1.07×10^-6g·cm^-3的氩气,电流脉冲峰值为27.81 kA,脉冲宽度为61.4 ns。改变放电参数进行模拟,结果表明：上升前沿越陡,则增益系数越大,电流脉冲上升时间在20~40 ns,电流峰值在25~40 kA,电流脉冲宽度在50~70 ns范围内,毛细管放电产生的等离子体状态比较理想,可获得较高的增益系数。     

制导光缆中光纤寿命预期

介绍了光纤寿命预期的疲劳实验方法和筛选实验方法。采用这两种方法，利用电子万能材料试验机和光纤筛选复绕机对室温下光纤进行了疲劳性能实验。实验得出，在张力小于850g的情况下，制导光纤的寿命可以达到10年以上；光纤的韦伯参数md和疲劳参数nd的大小影响光纤寿命。实验表明，当光纤的使用状态受力较大时，或使用贮存状态相差较大时，宜选用动态方法进行寿命预期；当贮存和使用状态受力变化不大时，宜选用筛选复绕方法预期光纤寿命。制导光纤寿命模型宜选用动态疲劳模型，通信光纤可选用筛选实验模型。实验还表明，提高光纤的抗疲劳因子nd和减小光缆中光纤的应变，可以更好地保持光缆中光纤的使用寿命和可靠性。     

Effect of Annealing on Structural and Magnetic Properties of a Thick （Ga,Mn）As Layer

We investigate effects of annealing on magnetic properties of a thick (Ga,Mn)As layer, and find a dramatic increase of the Curie temperature from 65 to 115K by postgrowth annealing for a 500-nm (Ga,Mn)As layer.Auger electron spectroscopy measurements suggest that the increase of the Curie temperature is mainly due to diffusion of Mn interstitial to the free surface. The double-crystal x-ray diffraction patterns show that the lattice constant of (Ga,Mn)As decreases with increasing annealing temperature. As a result, the annealing induced reduction of the lattice constant is mainly attributed to removal of Mn interstitial.     

碳硅石压腔在高温高压拉曼光谱研究中的应用

描述了碳硅石压腔的结构和特点。碳硅石压腔主要包括碳硅石压砧、支撑加压系统、加热系统和金属垫片等部分。合成碳硅石的硬度高、热导性好、膨胀系数小、热稳定性好,并且它的晶体颗粒大,透明度好,价格也很便宜,因此是一种很好的压砧材料。还介绍了应用碳硅石压腔对Na₂CO₃溶液、Na₂SO₄溶液、水的拉曼光谱进行高温高压原位测量的实例。     

Resonant Scattering of Relativistic Outer Zone Electrons by Plasmaspheric Plume Electromagnetic Ion Cyclotron Waves

The bounce-averaged Fokker-Planck equation is solved to study the relativistic electron phase space density （PSD） evolution in the outer radiation belt due to resonant interactions with plasmaspheric plume electromagnetic ion cyclotron （EMIC） waves. It is found that the PSDs of relativistic electrons can be depleted by 1-3 orders of magnitude in 5h, supporting the previous finding that resonant interactions with EMIC waves may account for the frequently observed relativistic electron flux dropouts in the outer radiation belt during the main phase of a storm. The significant precipitation loss of ~MeV electrons is primarily induced by the EMIC waves in H＋ and He＋ bands. The rapid remove of highly relativistic electrons （〉5MeV） is mainly driven by the EMIC waves in O＋ band at lower pitch-angles, as well as the EMIC waves in H＋ and He＋ bands at larger pitch-angles. Moreover, a stronger depletion of relativistic electrons is found to occur over a wider pitch angle range when EMIC waves are centering relatively higher in the band.     

Effects of multiple interruptions with trimethylindium-treatment in the InGaN/GaN quantum well on green light emitting diodes

In this study, the influence of multiple interruptions with trimethylindium(TMIn)-treatment in InGaN/GaN multiple quantum wells(MQWs) on green light-emitting diode(LED) is investigated. A comparison of conventional LEDs with the one fabricated with our method shows that the latter has better optical properties. Photoluminescence(PL) full-width at half maximum(FWHM) is reduced, light output power is much higher and the blue shift of electroluminescence(EL) dominant wavelength becomes smaller with current increasing. These improvements should be attributed to the reduced interface roughness of MQW and more uniformity of indium distribution in MQWs by the interruptions with TMIn-treatment.     

神光Ⅲ主机装置首次间接驱动内爆集成实验

基于新建成的神光Ⅲ主机装置开展了首次激光间接驱动内爆集成实验。国内首次采用多环脉冲整形激光注入黑腔产生X光辐射驱动内爆,通过优化激光打靶参数控制驱动不对称性,演示了以惯性压缩为主、收缩比约15倍的DT靶丸内爆实验能力, 实现了准一维的高静产额(YOC)和高中子产额的物理指标;其中,真空黑腔DT靶丸最高中子产额为1.91012,YOC达到60%;充气黑腔DT靶丸最高中子产额为2.41012,YOC大约70%。该实验为未来开展多台阶整形辐射驱动、更高倍数收缩比的高压缩内爆综合实验、验证点火靶物理设计和关键调控措施有效性奠定了基础。     

利用整体求值解中考题

<正>对于某些求值问题,如果按部就班,拘泥于常规解法,可能会费时费力,达不到预期效果,甚至无法求解.但如果能够根据题目特征,采取"整体求值"策略,则可缩短思维进程,简化解题过程,提高解题效率.下面以中考题为例予以说明.例1(2014年福建莆田)若x,y满足