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采用光纤传输技术的多串口以太网连接器设计
No full text在粒子加速器控制领域,为了避免现场存在的电磁辐射对控制设备及其连线的干扰影响,将串行通讯介质改为光纤连接,不失为一个好的解决方案。本文所介绍的设计工作解决了通过TCP/IP网关来扩展出8路光纤串口来连接多个设备达到远程控制的目的
单次分子镀法制备Sm和Eu厚靶
No full text研究了在异丙醇-硝酸体系中单次分子镀流程制备Sm和Eu厚靶的实验条件。确定了在20μm铍箔上进行Sm和Eu分子镀实验的最佳工艺条件为:两极间距3cm,电流密度3.8mA/cm2,分子镀过程持续1h。用分光光度法测定了分子镀的沉积效率均高于95%,所制备Sm和Eu靶膜的厚度分别在1.6和1.5mg/cm2
注氦尖晶石的红外光谱研究
No full text利用傅立叶变换红外光谱仪对注He尖晶石样品随退火温变化而引起光吸收性能的变化进行了研究。发现尖晶石样品在626.4cm-1附近的吸收峰随注入剂量的增加向小波数方向移动,而在随后退火过程该吸收峰随退火温度的增加而向大波数方向回复。该吸收峰的回复行为依赖于注入剂量和退火温度。认为在626.4cm-1附近吸收峰随注入剂量和退火温度的这种变化与尖晶石中He的俘获以及释放有关
Cross-correlation of excitation functions for different fragments and different scattering angles in Al-27(F-19, x)y reactions
No full textExcitation functions have been measured for different projectile-like fragments produced in Al-27(F-19,x)y reactions at incident energies from 110.25 to 118.75 MeV in 250 keV steps. Strong cross section fluctuations of the excitation functions are observed. The cross- correlation coefficients of the excitation functions for different atomic number Z and for different scattering angle theta(cm) have been deduced. These coefficients are much larger than the statistical theoretical calculated ones. This indicates that there are strong correlations between different exit channels in the dissipative heavy ion Collision of Al-27(F-19,x)y
The generalized second law of thermodynamics in generalized gravity theories
No full textWe investigate the generalized second law of thermodynamics (GSL) in generalized theories of gravity. We examine the total entropy evolution with time including the horizon entropy, the non-equilibrium entropy production, and the entropy of all matter, field and energy components. We derive a universal condition to protect the generalized second law and study its validity in different gravity theories. In Einstein gravity (even in the phantom-dominated universe with a Schwarzschild black hole), Lovelock gravity and braneworld gravity, we show that the condition to keep the GSL can always be satisfied. In f ( R) gravity and scalar-tensor gravity, the condition to protect the GSL can also hold because the temperature should be positive, gravity is always attractive and the effective Newton constant should be an approximate constant satisfying the experimental bounds.NSFC, Shanghai Education Commission, Science and Technology
NSFC 10575068
10604024
Shanghai Research Foundation 07dz22020
CAS Knowledge Innovation KJcx.syw.N2
hanghai Education Development Foundation
Innovation Foundation of Shanghai Universit
HIRFL today
No full textHIRFL was upgraded from beginning 2000. Besides of researches on nuclear physics, atomic physics, irradiative material and biology, the cancer therapy by heavy ion and hadron physics are being developing. The injector system of SFC+SSC can provide all ions from proton to uranium with higher intensity. The Cooling Storage Ring (CSR) has accelerated beams successful. The ions C-12(6+), Ar-36(18+), Xe-129(27+) have been accelerated up 1000MeV/u, 235MeV/u with about 10(9)similar to 10(8) ions per spill respectively. The beam momentum dispersion was measured from 4x10(-3) to 2x10(-4) after cooling by the electron cooler or similar to 4x10(-4) after accelerated to 1000MeV/u without cooling. In order to improve the nuclear structure and heavy isotope research in SFC+SSC energy domain, A Wien filter was added in front of RIBLL and gas was filled in first section of RIBLL; a new spectrometry SHANS has being installed. Presently, there are two starting version experimental setups at CSR
The level and distribution of chromosomal aberration of tomato seeds at different penetration depths of carbon ions
No full textThe relationship between the penetration depth and the level and distribution of chromosomal aberration of the root tip cells were investigated by exposure of the superposed tomato seeds to 80 MeV/u carbon ions. The results showed that on the entrance of the beam the chromosomal aberration level was low. Damage such as breaks and gaps were dominant. At the Bragg peak, the chromosomal aberration level was high. The yields of dicentrics, rings and disintegrated small chromosomes increased but the yields of breaks and gaps decreased. These results are consistent with the distribution of the physical depth dose pro. le of carbon ions. It is effective to deposit the Bragg peak on the seeds to induce hereditary aberration in the mutation breeding with heavy ions
The properties of halo structure for B-17
No full textThe total reaction cross section (1724 +/- 93 mb) of B-17 at the energy of 43.7 A MeV on C target has been measured by using the transmission method at the Radioactive Ion Beam Line in Lanzhou (RIBLL). Assuming B-17 consists of a core B-15 plus two halo neutrons, the total cross section of B-17 on C target was calculated with the zero-range Glauber model, where double Gaussian density distributions and Gaussian plus HO density distributions were used. It can fit the experimental data very well. The characteristic of halo structure for B-17 was found with a large diffusion of the neutrons density distribution
Configuration of the valence neutrons of B-17
No full textThe reaction cross section of B-17 on C-12 target at (43.7 +/- 2.4) MeV/u has been measured at the Radioactive Ion Beam Line in Lanzhou (RIBLL). The root-mean-square matter radius (R-rms) was deduced to be (2.92 +/- 0.10) fm, while the R-rms of the core and the valence neutron distribution are 2.28 fm and 5.98 fm respectively. Assuming a "core plus 2n" structure in B-17, the mixed configuration of (2s(1/2)) and (1d(5/2)) of the valence neutrons is studied and the s-wave spectroscopic factor is found to be (80 +/- 21)%.National Natural Science Foundation of China 10475098
10605033
10221003
Chinese Academy of Sciences CXTD-J2005-1
KJCX2-SW-N18
Hundred Talent Project of CAS 0501080BR
A low noise charge sensitive preamplifier with switch control feedback resistance
No full textIn this paper, the design and analysis of a new low noise charge sensitive preamplifier for silicon strip, Si(Li), CdZnTe and CsI detectors etc. with switch control feedback resistance were described, the entire system to be built using the CMOS transistors. The circuit configuration of the CSP proposed in this paper can be adopted to develop CMOS-based Application Specific Integrated Circuit further for Front End Electronics of read-out system of nuclear physics, particle physics and astrophysics research, etc. This work is an implemented design that we succeed after a simulation to obtain a rise time less than 3ns, the output resistance less than 94 Omega and the linearity almost good