一套用于重离子耗散反应测量的电离室望远镜

重离子耗散反应需要鉴别产物的电荷数Z,为此,研制了一套ΔE-E望远镜.ΔE由两个串接在一起的气体电离室ΔE₁和ΔE₂组成,位置灵敏硅半导体测量粒子的剩余能量E.被探测粒子的轨迹与电离室的电场方向平行.该望远镜具有很低的能量探测阈,较小的外尺寸和强的抗电磁干扰能力.重离子耗散反应¹⁹F+²⁷Al产物的激发函数实验测量表明,该望远镜的电荷分辨Z/ΔZ约为30.     

低温胁迫下香蕉叶片Chla荧光动力学参量的变化及其品种差异性

低温胁迫下,广东2号香蕉品种和巴西香蕉品种Williams的叶绿素(Chla)荧光动力学参量F_Ⅴ/F_m、ΔF_Ⅴ/F_T以及williams品种的F_IV/F_Ⅴ均呈下降趋势,两个品种的荧光上升半时间T_1/2及广东2号的F_IV/F_Ⅴ呈上升趋势.其中,Williams的F_Ⅴ/F_m、ΔF_Ⅴ/F_T和T_1/2的变化幅度小于广东2号,表明低温胁迫通过抑制光合电子传递速度和PSⅡ无活性中心含量的提高使香蕉叶片PSⅡ原初光能转换效率下降,相同低温对广东2号的影响大于对Williams的影响.F_Ⅴ/F_m和ΔF_Ⅴ/F_T可以作为评价香蕉幼苗抗冷性的物理指标.     

异氰酸分子NH(a1Δ)+CO(X1Σ+)通道在193nm的离子成像光解动力学研究

The photodissociation dynamics of isocyanic acid (HNCO) has been studied by the timesliced velocity map ion imaging technique at 193 nm. The NH(a¹Δ) products were measured via (2+1) resonance enhanced multiphoton ionization. Images have been accumulated for the NH(a¹Δ) rotational states in the ground and vibrational excited state (v=0 and 1). The center-of-mass translational energy distribution derived from the NH(a¹Δ) images implies that the CO vibrational distributions are inverted for most of the measured ¹NH(v|j) internal states. The anisotropic product angular distribution observed indicates a rapid dissociation process for the N-C bond cleavage. A bimodal rotational state distribution of CO(v) has been observed, this result implies that isocyanic acid dissociates in the S₁ state in two different pathways.     

碱金属Li,Na,K,Rb,Cs,Fr的ns2S1/2,np2P1/2,3/2, nd2D3/2,5/2 和nf2F5/2,7/2 里德伯能级理论研究

本文在多通道量子数亏损理论(MQDT)框架下,利用相对论多通道理论(RMCT),分别在冻结实近似、 考虑Δl=-1的偶极极化效应、Δl=+1的偶极极化效应、Δl=± 1的偶极极化效应、伸缩模效应以及同时考虑偶极极化效应和伸缩模效应等不同层次近似下,系统地计算了碱金属Li, Na, K, Rb, Cs和Fr七个里德伯系列的能级,即ns²S_1/2, np²P_1/2, np²P_3/2, nd²D_3/2, nd²D_5/2, nf²F_5/2 和nf²F_7/2.计算结果表明,电子关联效应对碱金属原子的里德伯能级的影响很大.总的来说,偶极极化效应比伸缩模效应重要,而在偶极极化效应中, Δl = + 1的偶极极化效应比Δl = - 1的偶极极化效应重要.但对于Na的ns²S_1/2,(nd²D_3/2,nd²D_5/2)里德伯系列的能级,和Li的(np²P_1/2,np²P_3/2)里德伯系列的能级,是伸缩模效应比较重要.     

光纤光栅温度传感的非线性现象

对光纤光栅温度传感反射波长相对漂移量与温度改变量的非线性问题进行了详细研究.通过对实验曲线的多项式拟合,求出了光纤光栅反射中心波长相对漂移量Δλ_C/λ_C与温度改变量ΔT的解析式,用对比法得到了温度灵敏度系数η表达式.取样计算表明:多项式能更好地反映Δλ_C/λ_C与ΔT的关系,证明了温度灵敏度系数η不是常量,而是随温度增加缓慢增大.     

介观电化学反应的随机热力学

In this work, we discussed the stochastic thermodynamics of mesoscopic electron transfer reactions between ions and electrodes. With a relationship between the reaction rate constant and the electrode potential, we find that the heat dissipation βq equals to the dynamic irreversibility of the reaction system minus an internal entropy change term. The total entropy change Δs_t is defined as the summation of the system entropy change Δs and the heat dissipation βq such that Δs_t=Δs+βq. Even though the heat dissipation depends linearly on the electrode potential, the total entropy change is found to satisfy the fluctuation theorem <(e)^-Δs_t>=1, and hence a second law-like inequality reads <Δs_t>≥0. Our study provides a practical methodology for the stochastic thermodynamics of electrochemical reactions, which may find applications in biochemical and electrochemical reaction systems.     

Multilayer transition in a spin-1 Blume–Capel model with RKKY interaction and quantum transverse anisotropy

Using mean-field theory, we have studied the effect of quantum transverse anisotropies with RKKY interaction on the multi-layer transition and magnetic properties of the spin-1 Blume--Capel model of a system formed by two magnetic multi-layer materials, of different thicknesses, separated by a non-magnetic spacer of thickness M. It is found that the multilayer magnetic order--disorder transition temperature depends strongly on the value of the transverse anisotropy. The multilayer transition temperature decreases when increasing the transverse anisotropy. Furthermore, there exists a critical quantum transverse anisotropy Δ_xL beyond which the separate transitions occur in the two magnetic layers. The critical transverse anisotropy Δ_xL decreases (increases) on increasing the non-magnetic spacer of thickness M (on increasing the crystal field), and Δ_xL undergoes oscillations as a function of the Fermi level.     

铁基纳米晶合金的介观阻抗率及应用

提出了铁基纳米晶合金介观阻抗率的物理概念，用Maxwell方程组求得其计算公式ρ=-μ{A}/{t}/Δ×H，该式表明铁基纳米晶合金的介观阻抗率与材料内部的介观磁场强度H、介观磁矢势A和介观磁导率μ有关，磁矢势A是由介观结构引起的量子力学效应，是由合金的微观结构决定的.这个理论很好地解释了铁基纳米晶粉末、粉芯     

用节点变分的代数方法研究双原子体系的完全振动能谱和离解能

对于使用实验数据作为原数据进行的数值计算, 由于实验误差的普遍存在, 在数值计算过程中可能存在对实验误差的放大效应, 使得微小的实验误差对数值计算的结果产生明显影响. 因此本文通过在AM (algebraic method) 方法中加入用以抵消实验误差的微小变分项δE, 从而将AM改进为节点变分的代数方法VAM (variational algebraic method). 该方法具有更广泛的适用范围, 尤其对处理那些实验数据较少、 误差较大、 已知的实验振动能级远离体系离解能的双原子体系效果明显. 本文利用VAM方法研究了AM方法难以处理的5¹Π_u⁷Li₂, (6d)¹Δ_g Na₂, (7d)¹Δ_gNa₂ 和5¹∑⁺ NaK 等不同碱金属双原子分子的完全振动能谱与离解能, 不但得到了与实验数据精确相符的理论结果, 还正确地预言了许多由于实验条件与技术原因而未能测得的物理数据. 充分表明了VAM 方法的可行性与正确性. 此处对数值误差的分析和物理思考对其他精确的数值计算 或数值模拟研究也有积极的参考意义.     

Cs2 NaMF6(M=Al,Ga):Cr3+络合分子体系局域结构和基态分裂的理论研究

采用双自旋轨道耦合系数模型并结合完全能量矩阵的方法对Cs₂NaMF₆(M=Al, Ga):Cr³⁺ 体系中Cr³⁺ 离子的基态分裂和局域结构进行了研究.通过模拟光谱和EPR谱确定了Cr³⁺ 取代 M³⁺ 形成的两种占位结构的畸变角,发现用双自旋轨道耦合系数模型与单自旋轨道耦合系数模型计算出的畸变角Δθ存在较大的差异.这表     

一种复合型空间软X射线--极紫外波段望远镜设计

根据空间对日观测的需要,提出了一种复合型宽波段范围的软X射线———极紫外望远镜的设计方案。该望远镜是把小结构尺寸的卡塞格林型极紫外波段正入射望远镜放置在软X射线波段,并由常用的Wolter Ⅰ型掠入射望远镜的中心部分组成。在软X射线和极紫外波段具有相同的焦距和视场角,共同使用同一个探测器,外形尺寸与相同指标的掠入射型望远镜一致,且在极紫外波段具有较高的角分辨率和光谱分辨率,适合于在空间进行对日观测使用。     

Fast Physical Optics Simulations of the Multi-Beam Dual-Reflector Submillimeter-Wave Telescope on the ESA PLANCK Surveyor

We present physical optics simulations of the multi-beam dual-reflector submillimeter-wave telescope on the ESA PLANCK surveyor designed for measuring the temperature anisotropies and polarization characteristics of the cosmic microwave background. The telescope is of a non-conventional Gregorian configuration, with two ellipsoidal reflectors providing a very large field of view at the focal plane where the array of 76 horn antennas feeding low-temperature detectors is located. We analyse the defocusing effects of the system, the polarization properties of the telescope, and the optical performance of the high-frequency channels based on special multi-moded horns operating at 545 and 857 GHz.     

液晶自适应光学的研究进展

概述了中科院长春光学精密机械与物理研究所(长春光机所)在液晶自适应光学方面的研究进展。针对液晶自适应光学技术存在的能量利用率低和校正频率慢的两大国际难题,液晶自适应光学研究组采取了一系列有效措施,不但攻克了能量利用率低的难题,且在校正频率方面也取得了质的飞跃。目前,系统能量利用率已从最初的5%提高到85%,基本和变形镜自适应光学系统的能量利用率相当;校正频率也从5 Hz提高到140 Hz,接近了校正大气湍流的实用化水平。利用该研究成果,分别研制了针对中科院国家天文台2.16 m望远镜和长春光机所1.2 m望远镜的液晶自适应光学系统并对恒星进行了有效校正,使1.2 m望远镜对恒星的分辨能力提高至约3倍衍射极限。     

双通道红外准直投影光学系统设计

介绍了一种双通道准直投影光学系统的设计。重点讨论了光学系统参数的分配以及利用Zemax光学设计软件多重结构功能进行优化的方法, 并利用蒙特卡罗分析对系统的公差进行了分析。光学系统采用望远系统和成像系统组合，在望远系统和成像系统之间的平行光路中插入分束镜引入第2个目标源通道。光学系统工作波段8 μm~12 μm, 视场12°，焦距228.3 mm，入瞳距800 mm，目标通道1和目标通道2的最大角分辨率分别为0.18 mrad和0.17 mrad，满足了投影系统的设计要求。     

The effect of the relativistic transformation law of angles on laser ranging of satellites moving in circular orbits equipped with a single retroreflector

It is shown that due to the relativistic transformation law of angles, a laser pulse reflected from a moving retroreflector propagates not strictly back, but at a small angle to the direction of the laser station. For this reason, the ray located on the periphery of a pulse reaches the receiving telescope of the laser station instead of the central ray of a pulse. As a result, the flux of electromagnetic energy received by the laser station is certainly less than the flux of energy in the vicinity of the central ray. The energy flux attenuation coefficient is assessed on the basis of numerical analysis. It is shown that if the receiving telescope is separated from the laser station in order to be mobile and is moving along the Earth’s surface so that the center of each spot formed by a pulse of the reflected light hits the telescope, then the electromagnetic energy flux during laser probing of the satellite will be higher by more than 100 times in comparison with the energy flux received by the stationary telescope of the laser station. From our study it follows that the maximum speed of motion of the centers of spots on the Earth’s surface does not exceed 8 km/h.     

Conceptual design of a phase-shifting telescope-interferometer

This paper deals with the theoretical principle and optical design of a phase-shifting telescope-interferometer. What is called a “telescope-interferometer” (T-I) is indeed a novel, recently proposed wavefront error (WFE) sensing technique, whose basic idea consists in combining the main pupil of a telescope with a second, off-axis reference arm. Then a weak modulation of the point spread function (PSF) is generated at the focal plane, allowing for direct phase measurements. We propose a notable improvement of the method, inspired from classical principles of phase-shifting interferometry. Herein are presented the alternative principle and its achievable measurement accuracy. The technique shows high performance excepted on narrow areas located near the pupil boundary. It is applicable to both ground or space telescopes and is suitable for the co-phasing of segmented mirrors, which is of prime importance in view of future giant telescope projects.     

A simulation of the thermal behaviour of the UK-NL millimeter wave telescope

To keep the thermally induced average telescope deformations within 15 m, a thermal design goal has been set which limits the temperature difference between all locations in the panels, backing structure and subframe to 1°C. Temperature gradients are caused by non-homogeneous exposure and by difference in response to a changing exposure for elements with different time constants.Thermal model simulations are used to identify the critical elements in the thermal design of telescope and enclosure. It is shown that an enclosure with a highly reflective paint with high infrared emissivity on the outside surface and an inside zinc coating with low infrared emissivity works as a highly effective radiation shield. A sprayed aluminium coating on the telescope makes free convection the dominant heat transfer mechanism. An enclosure with louvres works as a chimney forcing the inside air temperature to follow the ambient temperature to within a few degrees. The resulting temperature stratification in the area where the telescope reflector is located does not exceed 1.5°C. Structural analysis shows that temperature gradients in the subframe cause reflector surface deformations with a regular pattern, like gravitational deformations, which means that an error budget summation based on independent rms values is not necessarily valid. Knowing the structural analysis coefficients for differential thermal expansion one can decide which time constants in backing structure and subframe have to be matched to achieve optimal performance.     

Observation of the 2005 January 20 GLE Event Using Yangbajing Solar Neutron Telescope & Neutron Monitor

A solar cosmic rays Ground Level Enhancement(GLE) event associated with a X7.1/2b solar flare in 2005 January 20 was observed by the Yangbajing solar neutron telescope(SNT) and neutron monitor(NM), located at Yangbajing Tibet(90.53°E, 30.11°N, 4310m a.s.l) with the highest vertical geomagnetic cut-off rigidity of 14.1GV in NM network. The statistical significance of the counting rate enhancement recorded by solar neutron telescope in >40MeV channel was 3.7σ in the time window of 07:00—07:05UT and 6.0σ in the time window of 07:00—07:20UT, respectively. The onset time of 06:51—06:52UT for this GLE event was clearly observed by the Yangbajing NM. Our observation indicates that solar protons have been accelerated up to energies of >10GeV during this solar event.     

Space solar telescope in soft X-ray and EUV band

In this paper we have reviewed our achievements in soft X-ray and extreme ultraviolet (EUV) optics. Up to now, the research system of soft X-ray and EUV optics has been established, including light sources, detectors, calibrations, optical testing and machining of super smooth mirrors, and fabrications of multilayer film mirrors. Based on our achievements, we have developed two types of solar space telescopes for the soft X-ray and EUV space solar observations. One is an EUV multilayer normal incident telescope array including 4 different operation wavelength telescopes. The operation wavelengths of the EUV telescope are 13.0, 17.1, 19.5 and 30.4 nm. The other is a complex space solar telescope, which is composed of an EUV multilayer normal incident telescope and a soft X-ray grazing incident telescope. The EUV multilayer normal incident telescope stands in the central part of the soft X-ray grazing incident telescope. The normal incident telescope and the grazing incident telescope have a common detector. The different operation wavelengths can be changed by rotating a filter wheel.     

基于AR模型搜索迭代算法的望远镜跟踪误差分析

在大口径光学望远镜观测星体目标时,其跟踪误差主要由风载引起的望远镜跟踪抖动误差和大气湍流引起的跟踪误差组成.建立了望远镜跟踪误差的简化分析模型,提出了一种采用AR模型迭代算法将风载引起的望远镜跟踪抖动误差和大气湍流引起的跟踪误差分离的新方法,并在1.8 m望远镜上进行了实验验证.结果表明,风载引起的望远镜跟踪抖动误差与风向和风速直接相关,实验结果与理论分析比较符合.