稀土发光中心能级的热移位(Ⅰ)

在10—550K的温度范围内首次系统地研究了YAG:Nd^(3+)的斯塔克能级R_1和R_2的热移位。

稀土或过渡金属离子晶场光谱热移位的解析研究

按照稀土或过渡金属离子晶场光谱的理论，热移位包括不同特征的４项贡献．在本文中。

MgO:Cr^(3+)R线热移位的理论计算

按照掺稀土和过渡金属离子晶场的光谱热移位理论，热移位包括四个部份的贡献。本文运用该理论，对ＭｇＯ：Ｃｒ３＋的Ｒ线的热移位进行了拟合计算，并对其中最重要的参量值进行了理论计算。计算结果与大量实验数据符合很好。

Gd_3Sc_2Al_3O_(12)∶Cr^(3+)的能谱以及R线热移位的理论研究

通过对角化由强场方案和无耦合的三角基建立的三角畸变的八面体场中的d3离子完全能量矩阵,对Gd3Sc2Al3O12:Cr3+在低温下的能谱及波函数进行了拟合计算.同时分析了各个参数对部分能级的影响,定量地显示了能级分裂的影响因素.利用得到的波函数,采用光谱热移位理论,对Gd3Sc2Al3O12:Cr3+的R线热移位现象进行了分析和计算,各项计算结果均与实验符合较好,进一步反映了热移位的微观机制.

波函数混合对MgO:V^(2+)热移位的影响

根据掺稀土和过渡金属离子的晶场光谱热移位理论,光谱热移位应包括4部分贡献。利用波函数混合系数对其中作主要贡献的单声子项参量进行了理论计算,然后再对MgO:V^(2+)的R线的热移位进行了拟合计算,计算结果与大量实验数据符合很好。

基于热敏材料的超光谱隐身技术

简述了超光谱成像仪的探测特性,分析了超光谱成像仪隐身的原理,根据谱线热移位的物理机制和实验资料,提出了谱线热移位随温度变化大的掺金属离子晶体对超光谱的隐身,探讨了实现其隐身的途径与方法.

Improvement of pump-probe optical measurement technique using double moving stages

In order to improve the measurement precision and increase the reliability of the femtosecond laser transient thermoreflectance system, the relative optical path difference between pump and probe beams is prolonged, which can improve the fitting accuracy of the experimental data to the theoretical model. A modified experimental setup is devised with the pump path intercalated a moving stage identical to the one in the probe path, which extends the optical path difference of the probe beam relative to the pump beam from 4 to 8 ns. The measured results indicate that the uncertainty from the misalignment and divergence of both beams can be ignored when the last 4 ns experimental data are connected with those of the first 4 ns smoothly. The as-obtained thermal conductance of AI/Si and Cr/Si interfaces agrees well with the reported experimental values, which verifies the reliability of this modified version of this measurement.

Thermal activation parameters of V-5Cr-5Ti alloy under hot compression

In order to well understand the elementary mechanisms that govern the hot working process of a V？5Cr？5Ti alloy （mass fraction, %）, thermal activation parameters under compression were measured in a temperature range of 1373？1673 K by a Gleeble？3800 system. The results show that the stress exponentn is 4.87 and the activation energyQis 375.89 kJ/mol for the power law equation. The activation energy is determined as 288.34 kJ/mol, which is close to the self-diffusion energy of alloy （270？300 kJ/mol） by introducing a threshold stress（σ0） variable. The typical values of physical activation volume （Vp） and strain rate sensitivity （m） are measured as （120？700）b3 and 0.075？0.122, respectively, by the repeated stress relaxation tests. These activation parameters indicate that the rate controlling mechanism for V？5Cr？5Ti alloy compressed in ranges of 1373？1673 K and 0.001？1.0 s？1 is the dislocation climb by overcoming of forest dislocations.

宝力机械有限公司：日本CITIZEN数控机床A16

日本CITIZEN数控机床A16的换刀时间极短。同时，刀架排列方法，不受热移位影响，能够持续长时间工作，且保持高精度。

Prediction of the thermo-elastic properties of knitted structural composites using FEM

It is a very important and complex task to estimate the thermo-elasticproperties of a textile structural composite. In this paper, the finite element method (FEM) wasused for the prediction of the orthotropic thermo-elastic properties of a composite reinforced byglass fiber knitted fabric. In order to define the final 3-D configuration of the loop reinforcingstructure, the interactions between the adjacent loops, the large displacement and the contactelements without friction were considered. The values predicted were compared with the experimentalresults.

Theoretical Calculation of Energy Spectrum of YGG:Cr^(3+)and Thermal Shifts of Its R-Lines

With the strong-field scheme and trigonal bases, the complete d3 energy matrix in a trigonally distorted cubic-field has been constructed. By diagonalizing this matrix, the energy spectrum of YGG：Cr^3＋ at normal pressure and low temperature has been calculated. The g factor of the ground-state has been evaluated in terms of the energy spectrum. At the same time, by using the wavefunctions obtained from diagonalizing the complete d^3 energy matrix and Thermal Shifts theory, we calculate the thermal shifts of the sharp lines of YGG：Cr^3＋ and determine the relevant parameters. The calculated results are all in good agreement with the optical-spectrum and EPR experimental data. It is demonstrated that the obtained wavefunctions and the values of parameters are reasonable.

Microscopic—Theoretical Calculations of R—Line Thermal Shifts and Broadenings of MgO：V^2＋

A great improvement on a previous work (Phys. Rev. B48 (1993) 14067) has been made. By taking into account all the irreducible representations and their components in the electron-phonon interaction (EPI) as well as all the levels and the admixtures of basic wavefunctions within d3 electronic configuration, the values of all the parameters in the expressions of thermal shift (TS) and thermal broadening (TB) from EPI for the ground level, R level and R line of MgO:V2+ have microscopically been evaluated; and then, both the TS and TB of R line and various contributions to them have uniformly been calculated. The results are in very good agreement with the experimental data. It is found that all the three terms of TS from EPI are red shifts; the term of the contribution to TS from thermal expansion is blue shift. The Raman term is the largest, and the other terms are also important for TS. The R-line TS of MgO:V2+ comes from the first-order term of EPI. The elastic Raman scattering of acoustic phonons plays a dominant role in R-line TB of MgO:V2+. For calculations of both the TS and TB, it is very important to take into account all the admixtures of wavefunctions.

Microscopic Theoretical Calculations of R—Line Thermal Shifts and Broadenings of MgO：Cr^3＋

By taking into account all the irreducible representations and their components in the electron-phonon interaction (EPI) as well as all the levels and the admixtures of basic wavefunctions within d3 electronic configuration, the values of all the parameters in the expressions of thermal shift (TS) and thermal broadening (TB) due to EPI for the ground level, R level and R line of MgO:Cr3+ have microscopically been evaluated; and then, TS and TB of R line and various contributions to them have uniformly been calculated. The results are in very good agreement with the experimental data. It is found that all the three terms of TS due to EPI are red shifts; the Raman term is the largest one, and the optical-branch term and neighbor-level term are important for TS; the contribution to TS from thermal expansion is blue shift, which is also important. The R-line TS of MgO:Cr3+ comes from the first-order term of EPI. The elastic Raman scattering of acoustic phonons plays a dominant role in R-line TB of MgO:Cr3+. For both TS and TB, it is very important to take into account all the admixtures of basic wavefunctions within d3 electronic configuration.

Relationship between Meridional Displacement of the Monthly East Asian Jet Stream in the Summer and Sea Surface Temperature in the Tropical Central and Eastern Pacific

Previous studies have shown that meridional displacement of the East Asian upper-tropospheric jet stream (EAJS) dominates interannual variability of the EAJS in the summer months.This study investigates the tropical Pacific sea surface temperature (SST) anomalies associated with meridional displacement of the monthly EAJS during the summer.The meridional displacement of the EAJS in June is significantly associated with the tropical central Pacific SST anomaly in the winter of previous years,while displacements in July and August are related to tropical eastern Pacific SST anomalies in the late spring and concurrent summer.The EAJS tends to shift southward in the following June (July and August) corresponding to a warm SST anomaly in the central (eastern) Pacific in the winter (late spring-summer).The westerly anomaly south of the Asian jet stream is a result of tropical central Pacific warm SST anomaly-related warming in the tropical troposphere,which is proposed as a possible reason for southward displacement of the EAJS in June.The late spring-summer warm SST anomaly in the tropical eastern Pacific,however,may be linked to southward displacement of the EAJS in July and August through a meridional teleconnection over the western North Pacific (WNP) and East Asia.

Development of a Methodology for Determination and Analysis of Thermal Displacements of Machine Tools Using Finite Elements Method and Artificial Neural Network

In the processes of manufacturing, MT （machine tools） plays an important role in the manufacture of work pieces with complex and high dimensional and geometric accuracy. Much of the errors of a machine tool are those which are thermally induced which are from internal and external heat sources acting on the machine. In this paper, a methodology for determining and analyzing the thermal deformation of machine tools using FEM （finite element method） and ANN （artificial neural networks） is presented. After modeling the machine using FEM is defined the location of the heat sources, it is possible to obtain the temperature gradient and the corresponding thermal deformation at predetermined periods. Results obtained with simulations using the software NX.7.5 showed that this methodology is an effective tool in determining the thermal deformation of the machine, correlating the temperature reading at strategic points with volumetric deformation at the tool tip. Therefore, the thermal analysis of the errors in the pair tool part can be established. After training and validation process, the network will be able to make the prediction of thermal errors just stating the temperature values of specific points of each heat source, providing a way for compensation of thermally induced errors.

Elasticity solution of laminated beams subjected to thermo-loads

According to the two-dimensional(2-D) thermo-elasticity theory, the exact elasticity solution of the simply supported laminated beams subjected to thermo-loads was studied. An analytical method was presented to obtain the temperature, displacement and stress fields in the beam. Firstly, the general solutions of temperature, displacements and stresses for a single-layered simply supported beam were obtained by solving the 2-D heat conduction equation and the 2-D elasticity equations, respectively. Then, based on the continuity of temperature, heat flux, displacements and stresses on the interface of two adjacent layers, the formulae of temperature, displacements and stresses between the lowest layer and the top layer of the beam were derived out in a recurrent manner. Finally, the unknown coefficients in the solutions were determined by the use of the upper surface and lower surface conditions of the beam. The distributions of temperature, displacement and stress in the beam were obtained by substituting these coefficients back to the recurrence formulae and the solutions. The excellent convergence of the present method has been demonstrated and the results obtained by the present method agree well with those from the finite element method. The effects of surface temperatures, thickness, layer number and material properties of the plate on the temperature distribution were discussed in detail. Numerical results reveal that the displacements and stresses monotonically increase with the increase of surface temperatures. In particular, the horizontal stresses are discontinuous at the interface.

Solutions Of Boundary-Value Problems of the Generalized Theory of Couple-Stress Thermodiffusion

We have considered the basic dynamic homogeneous system of partial differential equations of generalized Green-Lindsay couple-stress thermodiffusion on the plane for homogeneous, isotropic elastic media with the centre of symmetry. We have constructed regular solution of the boundary problems on the line. In the works are obtained in quadrates the solution of the boundary-value problem of the generalized Green-Lindsay theory of couple-stress thermodiffusion, when on border of area are given： the component of normal of displacement vector, the component of touching of stress vector, rotations, flow of heat and flow of diffusion.

MgO:Cr^(3+)和MgO:V^(2+)的能谱随温度移位的拟合计算

全面计入电-声子耦合导致的热移位(其中包括~2T_1贡献的单声子项,Raman项,光学支项)与热膨胀导致的热移位,对MgO:Cr^(3+)与MgO:V^(1+)的R线热移位作了理论计算,结果与热移位、热膨胀系数,高压移位、声子谱与光谱、晶体密度、弹性常数与晶格常数等大量实验数据符合得很好.进而,将完全的d^3能量矩阵对角化,得到能谱与波函数,再通过电-声子相互作用矩阵元等一系列计算,从微观上算出单声子项的参量,结果与拟合实验得到的值符合得很好.结果表明:单声子项起主导作用(导致红移),而Raman项(导致蓝移)抵消了单声子项的一部分,再加上光学支项的贡献(导致红移),给出了电-声子耦合导致的热移位.

无化学修饰的小分子药物靶蛋白鉴定技术及其应用进展

鉴定小分子药物的靶蛋白对于理解药物的作用机理以及药物副作用至关重要。传统方法需要对药物进行化学修饰共价交联,可能会导致药物活性的改变。目前已经发展多种无需化学修饰便可以对药物靶蛋白鉴定的方法,包括药物亲和力反应靶标稳定性技术(Drug affinity responsive target stability,DARTS)、蛋白质氧化速率稳定性技术(Stability of proteins from rates of oxidation,SPROX)、细胞热移位分析技术(Cellular thermal shift assay,CETSA)和热蛋白组分析技术(Thermal proteome profiling,TPP)等。文中将介绍这些技术的原理、应用以及各自的优点和局限性,另外也介绍了这些技术最新的优化方案。

Measurement and Analysis of Movement of BPM Vacuum Chamber for HLS

The beam horizontal orbit at Hefei Light Source(HLS)was drifting all along while the storage ring was operating.To study this phenomenon,the displacement and the temperature variation of the BPM chamber were measured.By analyzing the measurement results,the main reason that explained the drifting phenomenon was found. The vacuum chamber following the dipole magnets was heated by the synchrotron light,which caused the increasing of the chamber surface temperature.The variation of the chamber temperature was the main reason why the BPM chamber held the horizontal displacement.To suppress the orbit drifting,a compensation method of BPM movement was proposed and its experimental results were given.