Synthesis of a Novel Aromatic Diamino-bridged Bis（β-cyclodextrin） and its Inclusion Complexation with Dyes Molecules

Bridged bis(β-cyclodextrin)s (CDs), as a very important family of CD derivatives, have been known that they can significantly alter the molecular binding ability and selectivity toward a variety of guests in comparison with parent cyclodextrin. Their two…     

多段构件组成的压杆平面内稳定

分析由若干段等截面或者变截面构件组成的压杆平面内稳定问题．从由三段等截面构件组成的压杆平面内稳定问题出发，对两端为变截面、中间为等截面构件组成的压杆的平面内稳定问题进行了分析，得出和两端为等截面构件情况类似的屈曲荷载计算公式．并对两端固接的情况进行了研究分析．     

养殖池塘沉积物的重金属分布及污染特征

浙江省淅西北地区淡水养殖池塘沉积物重金属调查研究表明，养殖池塘沉积物中7种重金属元素分布不均衡，差异也较大，除Hg和Cr元素外，其余重金属元素已大大超过土壤本底值．虽然其实测含量都未超出国家规定的标准值范围，但沉积物中重金属元素对养殖水环境、养殖品种存在的潜在污染与危害值得关注．污染指数评价显示，养殖池塘沉积物中主要污染物质为Cu和Cr，而Hg、Pb污染程度相对较轻．     

Temperature measurements using fiber optic polarization interferometer

A novel measurement method of temperature based on the phenomena that the phase difference between principle polarization states in the optical retarder is function of temperature is described. The polarization state of optical beam is changed as it passes through the optical retarder, which depends on the temperature. The temperature of optical retarder is determined by comparison of the power difference between principal polarization states. We demonstrate successfully the temperature measurement by using a polarization maintaining fiber as the optical retarder. With a 100 mm length of the fiber optic retarder, the change rate of phase difference on temperature was 0.236 rad/°C and the measurement error was ±0.038°C over the temperature range of −2.6 – +3.4°C. With a 11.5 mm length of the fiber optic retarder, the change rate of phase difference on temperature was 0.021 rad/°C and the measurement error was ±0.79°C over the temperature range of −8.5 – +86.5°C.     

肿瘤微波热疗的温度场预示及热损伤研究

本文将热损伤的产生和影响引入到肿瘤的微波热疗中。运用微波能量比吸收率SAR的分布分析了微波在组织中的传输和吸收过程,并对微波热疗过程中的温度场、热损伤分布以及血液灌注率的变化进行了数值模拟。     

Ab-initio molecular dynamics simulation on nano-system under external pressure

A new constant-pressure molecular dynamics (MD) method is developed to simulate the dynamic behavior and structure transition of finite system under external pressure. In this method, no artificial parameter is introduced and the computation overheads are very small. As an application, a hard-soft transition of single wall carbon nanotube (SWCNT) under external pressure is found, which is in agreement with the experiments.

     

由Schr?dinger算子定义的Riesz变换的Lp估计

本文主要讨论了当非负位势 V(x)属于某逆Holder类时,由一致椭圆算子L=-div(A(x))+V(x)所定义的 Riesz变换在 L^p空间的有界性。     

Transition‐metal‐catalyzed reactions of 5‐methylene‐2‐oxazolidinone and 5‐methylene‐1,3‐thiazolidine‐2‐thione with isocyanates

5‐Methylene‐2‐oxazolidinone (1) and 5‐methylene‐1,3‐thiazolidine‐2‐thione (4) react with various isocyanates to give the corresponding urethanes 3 and 5 in high yields in the presence of palladium(0) or palladium(II) catalyst under mild reaction conditions. A mechanism is proposed. Copyright © 2003 John Wiley & Sons, Ltd.     

利用相干渡越辐射测量电子束团长度的分析与计算

利用相干渡越辐射(CTR)测量短和超短电子束团长度是国际上束测领域新发展的频域测量技术.文中理论分析和数值计算了北京自由电子激光装置的皮秒级的射频电子束团序列产生的CTR,当辐射波长在长于束长(4ps)时,渡越辐射发生相干增强效应;与非相干渡越辐射相比,当λ≥2πσz时,增强的倍数约等于束团中粒子的数目(10⁸);CTR从亚毫米波到毫米波段呈宽带连续谱特性;渡越辐射能量主要集中在轴线附近,宏脉冲辐射能量高达几毫焦.设计采用偏振型束团长度测量系统,利用CTR自相关技术,实验测量该束团序列的纵向长度,并藉助傅里叶变换光谱法,推求束团电子分布.     

Probabilistic Teleportation of a Three-Particle State

A scheme for teleporting a three-particle state is proposed when three pairs of entangled particles are used as quantum channels. Quantum teleportation can be successfully realized with a certain probability if the receiver adopts an appropriate unitary-reduction strategy. The probability of successful teleportation is determined by the smaller coetficients of the three entangled pairs.