Three kinds of extraneous factors in Dixon resultants

Dixon resultant is a basic elimination method which has been used widely in the high technology fields of automatic control, robotics, etc. But how to remove extraneous factors in Dixon resultants has been a very difficult problem. In this paper, we discover some extraneous factors by expressing the Dixon resultant in a linear combination of original polynomial system. Furthermore, it has been proved that the factors mentioned above include three parts which come from Dixon derived polynomials, Dixon matrix and the resulting resultant expression by substituting Dixon derived polynomials respectively. This work was supported by the National Key Basic Special Funds of China (Grant No. 2004CB318003), the Knowledge Innovation Project of the Chinese Academy of Sciences (Grant No. KJCX2-YW-S02), the National Natural Science Foundation of China (Grant No. 90718041), Shanghai Leading Academic Discipline Project (Grant No. B412) and the Doctor Startup Foundation of East China Normal University (Grant No. 790013J4)     

The design and construction of a pulsed beam generation system based on high intensity cyclotron

In order to perform the studies on a pulsed beam generation system based on a high intensity cyclotron, a test beam line with a pulsed beam generation for a 10 MeV compact cyclotron (CYCIAE-10) has been designed and constructed at China Institute of Atomic Energy (CIAE). A 70 MHz continuous H-beam can be pulsed to the pulse length of less than 10 ns with a repetition rate of 4.4 MHz. The sine waveform with a frequency of 2.2 MHz is adopted for the chopper and a mesh structure with single drift and dual gaps is used for the 70 MHz buncher. A helical resonator is designed and constructed based on simulations and experiments on the RF matching for the chopper. A helical inductance loop that is exceptionally large of its kind and equipped with water cooling for the resonator has been successfully wound and a 500 W solid RF amplifier has been manufactured. A special measuring device has been designed, which can be used to measure both the DC beam and the pulsed beam. The required pulsed beam was obtained after pulsed beam tuning.     

Distribution threshold values of CaCl_2 onto the 10X-zeolite and macro-pore silica gel

The calcium chloride used for adsorption separation of ammonia is promising for its large adsorptive capacity and lower desorption temperature,but difficult to develop because of the liable expansion,lump and chip in the adsorption/desorption process.Composite adsorbents made by monolayer dis-persion of calcium chloride onto carriers with high surface areas exhibit better adsorptive capacity and stability.Several models were developed to confirm the maximum monolayer dispersion capacity of calcium chloride ...     

Distribution threshold values of CaCl<Subscript>2</Subscript> onto the 10X-zeolite and macro-pore silica gel

The calcium chloride used for adsorption separation of ammonia is promising for its large adsorptive capacity and lower desorption temperature, but difficult to develop because of the liable expansion, lump and chip in the adsorption/desorption process. Composite adsorbents made by monolayer dispersion of calcium chloride onto carriers with high surface areas exhibit better adsorptive capacity and stability. Several models were developed to confirm the maximum monolayer dispersion capacity of calcium chloride onto the carriers (the distribution threshold value), and the closely packed monolayer dispersion model was considered the most suitable for this study. The distribution threshold values given by this model were 0.60 g CaCl₂/(g 10X-zeolite) and 0.38 g CaCl₂/(g SiO₂). When the divalent salt was dispersed onto the carriers, however, anions were separated into two types, causing that the entropy of the system tended to increase and the system was not stable. To minimize the entropy, a new model was put forward as the modified closely packed monolayer dispersion model. Based on this model, the distribution threshold values are 0.52 g CaCl₂/(g 10X-zeolite) and 0.33 g CaCl₂/(g SiO₂), respectively. The distribution threshold values were also gained experimentally by XRD quantitative phase analysis: 0.61 g CaCl₂/(g 10X-zeolite) and 0.31 g CaCl₂/(g SiO₂). Comparison between experimental values of distribution threshold with theoretical ones based on two different model showed that the closely packed monolayer dispersion model fits the monolayer dispersion of calcium chloride onto micro-pore carrier —10X-zeolite, and the modified closely packed monolayer dispersion model is more suitable for the bigger aperture carrier —macro-pore silica gel. Supported by the National Natural Science Foundation of China (Grant No. 20576080)     

玻璃光盘基片

本文对制备光盘的各种材料的性能做了比较,叙述了采用白冕平板玻璃研制直径为133.35mm可擦除光盘基片的工艺过程,以及产品达到的性能指标。     

High performance computation on beam dynamics problems in high intensity compact cyclotrons

This paper presents the research progress in the beam dynamics problems for future high intensity compact cyclotrons by utilizing the state-of-the-art high performance computation technology. A “Start-to-Stop” model, which includes both the interaction of the internal particles of a single bunch and the mutual interaction of neighboring multiple bunches in the radial direction, is established for compact cyclotrons with multi-turn extraction. This model is then implemented in OPAL-CYCL, which is a 3D object-oriented parallel code for large scale particle simulations in cyclotrons. In addition, to meet the running requirement of parallel computation, we have constructed a small scale HPC cluster system and tested its performance. Finally, the high intensity beam dynamics problems in the 100 MeV compact cyclotron, which is being constructed at CIAE, are studied using this code and some conclusions are drawn.

     

The design and construction of a pulsed beam generation system based on high intensity cyclotron

In order to perform the studies on a pulsed beam generation system based on a high intensity cyclotron, a test beam line with a pulsed beam generation for a 10 MeV compact cyclotron (CYCIAE-10) has been designed and constructed at China Institute of Atomic Energy (CIAE). A 70 MHz continuous H-beam can be pulsed to the pulse length of less than 10 ns with a repetition rate of 4.4 MHz. The sine waveform with a frequency of 2.2 MHz is adopted for the chopper and a mesh structure with single drift and dual gaps is used for the 70 MHz buncher. A helical resonator is designed and constructed based on simulations and experiments on the RF matching for the chopper. A helical inductance loop that is exceptionally large of its kind and equipped with water cooling for the resonator has been successfully wound and a 500 W solid RF amplifier has been manufactured. A special measuring device has been designed, which can be used to measure both the DC beam and the pulsed beam. The required pulsed beam was obtained after pulsed beam tuning.

     

多变元Sylvester结式与多余因子

经典的Sylvester结式方法是代数几何的一种基本消元方法,但它一次只能处理1个变元2个方程的多项式系统.本文将Sylvester结式扩展到n个变元n+1个方程的多项式系统,并且证明了新的多变元的Sylvester结式包含在原多项式系统的理想中.同时,给出了一种去掉其部分多余因子的方法.     

Organic-inorganic Hybrid Materials Based on Molybdophosphate and Organic Polyammonium

A new organic-inorganic hybrid compound （dienHs）2（P2Mo5O23） （1） [dien=NH（CH2CH2NH2）2] has been hydrothermally synthesized and characterized by elemental analyses, IR spectrum, thermogravimetric analysis, and the single crystal X-ray diffraction technique. Compound 1 crystallizes in the triclinic system with space group P1 and a=0.9790（2） nm, b=0.9922（2） nm, c= 1.4644（3） nm, α=95.510（10）°, β=98.860（10）°, γ=95.700（10）°, V=1.3895（5） nm^3, Z=2, R=0.0465. The results show that the compound consists of dienH3^3＋＋ and P2Mo5O23^6-, and the heteropoly anion P2Mo5O23^6- is connected to a 1-D chain structure with the protonated dien by hydrogen bonds.     

环境响应性多肽自组装研究进展

分子自组装广泛存在于自然界中,参与生物体的各项生命活动,从而确保生物体相关生理功能的实现和生化反应的有序进行.多肽自组装作为分子自组装的重要组成部分,其良好的生物相容性为构建具有重要应用价值的生物医用材料提供了新的思路.本文总结了多肽自组装过程中主要的驱动作用力;简述了多肽自组装形成的主要结构;详细介绍了自组装过程中环境变化,包括pH、温度、离子强度、特殊离子、氧化还原态以及光照等,对于环境响应性多肽自组装结构和性质的影响;并且阐述了多肽自组装生物材料的应用方向和前景,希望为该领域的进一步研究提供参考.