金刚石窗口冷却Yb3+∶YAG DPSSL设计

针对高功率二极管重复率抽运的V型非稳腔Yb3+∶YAG激光头，提出了利用金刚石窗口冷却和直接水冷相结合的复合冷却设计.在YAG片的抽运面进行直接水冷，同时在激光提取面利用金刚石窗口冷却介质.金刚石优异的导热性能不仅能够有效地冷却激光介质，还能消除横向的温度梯度，解决了高功率激光器冷却和高功率抽运的矛盾.模拟结果表明对掺杂10 at %厚度为1.6 mm的Yb3+∶YAG片在抽运功率密度为20 kW/cm2，重复频率为10 Hz的条件下，要将最高温度控制在可接受的范围内（比如320 K），周围冷却水的对流换热系数约为4000 W/m2K.     

双面金属包覆介质波导模序数的判别方法

在双面金属包覆介质波导中 ,随着介质层厚度的变化 ,会出现TM0 模与TM1 模的分离和简并两种状态 ,从而影响衰减全反射 (ATR)谱中模序数的确认。通过对金属波导的理论分析和实验研究 ,提出了三种模序数确认方法 :本征角计算法、吸收峰全峰半宽比较法和吸收峰峰间距比较法 ,实现了两种状态下对模序数的准确判断     

森谱的界

设λ_k(F)是树或者森的第k大特征值,[x]是不超过x的最大整数,q是F的边独立数.本文证明了:对于1≤k≤[(q 1)/2]有λ_k(F)≥1,并且这个下界是最好可能的;对于1≤i≤[q/2],若q为偶数,则有λ[(q 1)/2] i(F)≥2cos((2iπ)/(4i 1)),若q为奇数,则有λ_([(q 1)/2] i)(F)≥2cos(((2i 1)π)/(4i 3)),     

HeI photoelectron spectroscopic (PES) and quantum chemistry study on the dimeric compound of 2(5H) furanone

The He1 photoelectron (PE) spectra of both 2(5H) furanone and itstrans-chair-dimeric-compound (t-c-DFN) are reported. The assignment of the PES bands is made on the basis of band shapes, the PES results of the molecules which have the similar atomic groups, and the restricted Hartree-Fock (RHF) calculations for the molecules studied. From the results of both PES experimental and theoretical calculations, it is proved that the ionization potential (IPS) of the HOMO for the dimeric-compound is lower than that of the HOMO for the monomer. And the total energy computed for thet-c-DFN is the lowest in the four possible configurations of dimeric-compounds of 2(5H) furanone. Therefore the synthesis oft-c-DFN is also the easiest. Project supported by the National Natural Science Foundation of China.     

A compactness result for Kähler Ricci solitons

In this paper we prove a compactness result for compact Kähler Ricci gradient shrinking solitons. If (Mi,gi) is a sequence of Kähler Ricci solitons of real dimension n?4, whose curvatures have uniformly bounded Ln/2 norms, whose Ricci curvatures are uniformly bounded from below and μ(gi,1/2)?A (where μ is Perelman's functional), there is a subsequence (Mi,gi) converging to a compact orbifold (M_∞,g_∞) with finitely many isolated singularities, where g_∞ is a Kähler Ricci soliton metric in an orbifold sense (satisfies a soliton equation away from singular points and smoothly extends in some gauge to a metric satisfying Kähler Ricci soliton equation in a lifting around singular points).     

A semiclassical reactive flux method for the calculation of condensed phase activated rate constants

A semi classical reactive flux algorithm for calculating thermally activated rate constants is presented which is based on a semi-classical transition state theory due to Chapman, Garrett and Miller [J. Chem. Phys. 63 (1975) 2710]. This reactive flux technique, when combined with the semiclassical TST, enables one to describe dynamical recrossings of the transition state on the same footing as tunneling effects. Most importantly, the method is readily applied to nonlinear multidimensional systems over a wide range of temperatures. It will be shown that the method works very well for a variety of existing models.     

K2O-ZnO-Al2O3-B2O3-SiO2系掺Cr3+透明莫来石微晶玻璃的研究

采用了X射线衍射、透射电镜和吸收光谱及荧光光谱技术研究了K2O－ZnO-Al2O3-B2O3－SiO2系掺Cr^3 玻璃的析晶性能和光谱。研究结果表明：在K2O－Al2O3-B2O3-SiO2系掺Cr^3 玻璃的基础上引入ZnO后，析晶性能明显改善；析晶温度降低，析出的纳米莫来石微晶均匀、规则；微晶玻璃的发光强度明显增强。     

Millikan′s油滴实验数据处理透析

本文从误差传递的角度出发，代入合理的数据，来说明目前高校实验中对此内容的数据处理的问题所在以及应怎样采取措施解决。     

钻柱系统振动测试和分析

利用应变和压电测试系统以及随机信号和振动分析系统,在模型和试验钻机上,进行了钻柱系统的固有频率、响应、钻头的动态压力、功率谱和动态传递函数等测试分析。在横向振动支承条件,岩石的刚度以及动态碎岩机理等方面得到了一些有益的研究结果,并提出了岩石刚度动态测定法。以上研究为理论分析提供了依据。     

A rapid and accurate 3-(4,5-dimethyl thiazol-2-yl)-2,5-diphenyl tetrazolium bromide colorimetric assay for quantification of bacteriocins with nisin as an example

The objective of this study is to propose a more accurate and faster MTT [3-(4,5-dimethyl thiazol-2-yl)-2,5-diphenyl tetrazolium bromide] colorimetric assay (MCA) for quantitative measurement of polypeptide bacteriocins in solutions with nisin as an example. After an initial incubation of nisin and indicator bacterium Micrococcus luteus NCIB 8166 in tubes, MTT was added for another incubation period. After that, nisin was quantified by estimating the number of viable bacteria based on measuring the amount of purple formazan produced by cleavage of yellow tetrazolium salt MTT. Then MCA was compared to a standard agar diffusion assay (ADA). The results suggested a high correlation coefficient (r ²=0.975±0.004) between optical density (OD) and the inhibitory effect of nisin on a bacterial strain Micrococcus luteus NCIB 8166 at a range of 0.125~32 IU/ml. The MCA described in this study was very quick. Quantification of nisin took only 7~8 h and the detection limit was at the level of 0.125 IU/ml when compared to 12 IU/ml and 24~28 h for ADA. The MCA provides an accurate and rapid method for quantification of nisin in solutions and is expected to be used for quantification of other antimicrobial substances.