短寿命核转轮传送装置

在中国原子能科学研究院的串列式静电加速器上建立了传送短寿命核的转轮装置，可用于鉴别和研究寿命短至几秒的核素。该装置已用于新的缺中子核素＾９０Ｒｕ的鉴别及其半衰期和衰变γ的测量。     

关于合成265Bh实验的可行性分析

分析了目前关于超重核研究的现状,结合现有的设备及条件,在合成259Db以后,下一次实验的目标核初步确定为107号元素的新同位素265Bh.描述了对MG转轮收集探测系统的实验检验结果.实验中成功地观察和测量了24Mg+232Th的产物252No的母子体的α衰变谱,为下一步合成265Bh完成了部分预实验工作.另外,也给出了下一个目标核的衰变特性的理论预言值,同时也选择了产生该目标核的弹靶组合及反应道,并对生成截面进行了粗略估计,给出了该核的可观测性产额及可行性分析. The present status of investigation on the surperheavy nuclei are analyzed. After 259Db synthesized, the next objective nuclide is determined to be265Bh, a new isotope of Z=107 element, according to our existing available equipment and conditions.The test result of the MG rotating wheel collection and detection system is described. The α decay spectra of mother daughter of the product252No from24Mg +232Th reaction are observed and measured successfully in this test experiment. It is regarde...     

短寿命核转轮传送装置

在中国原子能科学研究院的串列式静电加速器上建立了传送短寿命核的转轮装置,可用于鉴别和研究寿命短至几秒的核素．该装置已用于新的缺中子核素９０Ｒｕ的鉴别及其半衰期和衰变γ的测量． A wheel device for transporting short-lived nuclei has been constructed at the HI-13 tandem accelerator of CIAE. The device can be used in the identification and investigation of nuclides with life-times as short as a few seconds. With the aid of this device a new nutron-deficient nuclide 90Ru has been identified. Its half-life and decay γ-rays have been measured.     

硅胶除湿转轮性能优化实验研究

为了提高除湿转轮的除湿性能,降低吸附热对除湿性能的影响,将导热硅脂作为传热基质负载在不同扇形区域的硅胶转轮转芯基体表面,搭建硅胶除湿转轮性能优化实验台,研究了除湿转轮动态除湿性能.实验结果表明:硅胶除湿转轮的除湿性能随导热硅脂负载区域的增大先增大后减小,导热硅脂负载区域为2/8时,具有最佳的除湿性能,除湿量达到了0.3...     

单转轮除湿空调系统夏季工况实验研究

介绍了单转轮除湿热泵空调系统,通过实验,对其系统进行了夏季工况除湿性能研究。当除湿区入口干球温度在28℃~40℃之间以温差2℃为一工况增加,温度一定时含湿量在8~20g/kg之间以2g/kg为一工况增加时,新风按20%比例与回风混合,混合风由硅胶转轮除湿后再经过热泵蒸发器冷却降温送入空调区。实验结果表明,从热泵蒸发器处理后的空气温度稳定在20℃左右,满足送风要求;从热泵冷凝器出来的空气温度为60℃左右,满足对转轮再生温度的要求;热泵机组的COP均值为2.7;硅胶转轮除湿率均值为0.32,除湿效率比较明显。     

三种固体转轮除湿系统的模拟比较

分别建立单级转轮系统、厚转轮系统以及两级转轮系统的模型.利用模型比较分析了三种系统的性能.结果显示两级系统处理的潜热、显热负荷和产生的冷量均为最大,但其COP在三者之中最低;厚转轮系统与单级系统的差异不显著.通过实际的两级除湿系统的实验结果,验证模拟结果的准确性.     

新型复合干燥剂转轮的优化设计和实施

本文利用计算机仿真的方法对硅胶、氯化钙及其复合干燥剂应用于转轮上的除湿性能进行了分析,提出了新型转 轮设计的几个原则,加工制作了一个新型复合干燥剂转轮,并进行了对比实验研究,结果表明:在典型热湿气候条件下, 复合干燥剂转轮在再生温度低于120℃时,其除湿量比传统硅胶干燥转轮要平均高出约20％。     

40Ar+238U 实验介绍

主要介绍了利用兰州重离子加速器提供的270 MeV的40Ar离子束轰击238U靶，通过熔合蒸发反应进行试合成Z=110附近的新同位素的实验情况。分析了目前关于超重核研究的现状并描述了这次实验的目的、 可行性分析、 实验装置以及实验过程等。本次实验仍然用氦喷嘴技术对产物进行传输， 并用一套具有数对探测器组的转轮收集探测系统对产物进行收集和测量。 The state of the experiment to produce the new isotopes around Z=110 are presented in this paper. The emphasis is laid upon introducing the experiment purpose, the set up and the feasibility for producing this objective nuclide. In the experiment the new isotopes were produced by the complete fusion evaporation reaction of 238U with 270 MeV 40Ar at the Sector Focus Cyclotron (SFC) of Heavy Ion Research Facility in Lanzhou(HIRFL). The reaction products were also transported and collected by using the helium jet technique and rotating wheel apparatus.     

双级热管转轮除湿空调系统性能研究

转轮除湿空调系统是将转轮除湿机与常用冷却方式相结合实现空调制冷的新型空调系统。为降低转轮除湿空调系统的再生能耗以及提高系统的冷却能力,本文提出双级热管转轮除湿空调系统,系统利用重力热管的冷凝段实现转轮除湿机的再生,蒸发段实现处理空气的冷却。建立了双级热管除湿转轮空调系统传热传湿模型,模拟分析了系统在不同工况下系统的降温除湿特性。研究表明,处理空气进口温度越高,系统的冷却能力越强但系统的除湿能力降低;处理空气湿度越高,系统的除湿能力越强,但系统的冷却能力降低;再生温度越高,系统除湿能力越强,系统热力性能系数越低,但冷却能力降低。综合降温除湿能力及节能要求,双级热管转轮除湿空调系统的再生温度不宜过高,推荐≤80℃。     

除湿转轮的焓湿分析与性能优化

为了探明空气进口参数对除湿转轮性能的影响,本文基于除湿转轮进出口空气的焓湿分析,提出了一个评价转轮除湿性能的综合技术指标(DCOP),在理论和实验上证实了转轮除湿性能严重依赖于再生温度和处理空气的温湿度, 同时对理论模拟结果进行了实验验证,并对转轮除湿性能进行了空气进口参数优化分析。     

Beyond mean field approach to the beta decay of medium mass nuclei relevant for nuclear astrophysics

The Gamow-Teller strength distributions for the β decay of the ground state as well as the lowest excited states of the rp-process waiting point nuclei ⁶⁸Se and ⁷²Kr are obtained within the complex Excited Vampir variational approach using realistic effective interactions and a rather large model space. The shape mixing is consistently described for both the states in the even-even parent and the states in the odd-odd daugther nucleus. The influence of the shape mixing accounted by the different effective interactions used and comparison with the available data are presented. The possible influence of the decay of the lowest excited states of the parent nuclei in the astrophysical environment of X-ray bursts is discussed.Gamow-Teller strength distributions, β-decay half-lives, and β-delayed neutron emission probabilities for neutron-rich Zr nuclei are investigated for the first time within the complex Excited Vampir approach using a large model space. Comparison with available data and predictions relevant for the astrophysical r process are presented.     

Competition between α-decay and β-decay for heavy and superheavy nuclei

In this work, the β-stable region for Z 90 is proposed based on a successful binding energy formula.The calculated β-stable nuclei in the β-stable region are in good agreement with the ones obtained by Mo¨ller et al. The half-lives of the nuclei close to the β-stable region are calculated and the competition between α-decay andβ-decay is systematically investigated. The calculated half-lives and the suggested decay modes are well in line with the experimental results. The decay modes are mostly β--decay above the β-stable region. Especially for Z 111,all the decay modes are β--decay. Regarding the nuclei above the β-stable region, α-decay and β--decay(α+β-)can occur simultaneously when Z 112. This is a very interesting phenomenon. The competition between α-decay and β-decay is very complex and drastic below the β-stable region. The predictions for half-lives and decay modes of the nuclei with Z =107–110 are presented in detail.     

Reaction 55Mn + 159Tb : preparation for the synthesis of new elements

The complete fusion reaction of \begin{document}$^{55}$\end{document}Mn + \begin{document}$^{159}$\end{document}Tb was studied on the gas-filled recoil separator SHANS2. Nineteen ER - α\begin{document}$_{1}$\end{document} - α\begin{document}$_{2}$\end{document} decay chains from \begin{document}$^{210}$\end{document}Th produced from the 4n evaporation channel were observed. The α-particle energy and half-life of \begin{document}$^{210}$\end{document}Th were determined as 7922(14) keV and 14(4) ms, respectively. In addition, the decay properties of \begin{document}$E_{\alpha}$\end{document} = 7788(14) keV and \begin{document}$T_{1/2}$\end{document} = 36\begin{document}$^{+15}_{-8}$\end{document} ms were obtained for \begin{document}$^{211}$\end{document}Th. The measured α decay properties of \begin{document}$^{210}$\end{document}Th and \begin{document}$^{211}$\end{document}Th were consistent with literature data. The cross sections were measured to be 0.59\begin{document}$^{+0.25}_{-0.23}$\end{document} nb and 0.19\begin{document}$^{+0.12}_{-0.09}$\end{document} nb for \begin{document}$^{210}$\end{document}Th and \begin{document}$^{211}$\end{document}Th, respectively. The equilibrium charge state of the recoiled nucleus \begin{document}$^{210}$\end{document}Th was determined experimentally. The new data were helpful for estimating the equilibrium charge states of elements 119 and 120, which could be produced via the \begin{document}$^{240}$\end{document}Pu(\begin{document}$^{55}$\end{document}Mn, 3n)\begin{document}$^{292}$\end{document}119 and \begin{document}$^{243}$\end{document}Am(\begin{document}$^{55}$\end{document}Mn, 3n)\begin{document}$^{295}$\end{document}120 reactions, respectively.     

Entrance channels and alpha decay half-lives of the heaviest elements

The barriers standing against the formation of superheavy elements and their consecutive decay have been determined in the quasimolecular shape path within a Generalized Liquid Drop Model including the proximity effects between nucleons in a neck, the mass and charge asymmetry, a precise nuclear radius and the shell effects given by the Droplet Model. For moderately asymmetric reactions double-hump potential barriers stand and fast fission of compact shapes in the outer well is possible. Very asymmetric reactions lead to one hump barriers which can be passed only with a high energy relatively to the superheavy element energy. Then, only the emission of several neutrons or an particle can allow to reach an eventual ground state. For almost symmetric heavy-ion reactions, there is no more external well and the inner barrier is higher than the outer one. Predictions for partial decay half-lives are given.     

Status Report on the Double-Beta-Decay Experiment NEMO3

The aim of the NEMO collaboration is to search for neutrinoless double-beta decay and thus to investigate physics beyond the Standard Model. The expected sensitivity for the effective neutrino mass is on the order of 0.1 eV. The NEMO3 detector will be completed and ready to start measurements by the end of the year 2001. Since June 2000, three contiguous sectors have been operating in the Fréjus Underground Laboratory (France). This trial run has provided a check on the functionality of the counters and the tracking device. The status of the experiment, the results obtained with the three sectors, as well as expected backgrounds and source radiopurity are presented.     

基于多DSP的车轮外形磨耗动态检测系统

针对矿井绞车车轮外形磨耗动态检测问题,构建了由线状光源、CCD、多DSP图像处理子系统等组成的系统.对于车轮磨耗图像的获得和外形曲线的提取,重点阐述了多DSP处理系统在绞车车轮外形磨耗实时检测中的设计问题.车轮外形的提取采用了一种梯度边缘检测算法来实现,并给出了磨耗值计算的变换矩阵.初步试验表明该系统的检测误差不大于0.3 mm.     

Present Status of the Experiment TGV II

Present status of the experiment TGV II is given. The experiment TGV II is devoted to the measurement of double-beta decay of ¹⁰⁶Cd and ⁴⁸Ca. The new HPGe multi-detector TGV spectrometer has been constructed and installed in the Modane underground laboratory (in France). Preliminary results of the first background measurement are presented.     

A Novel Framework for Anomaly Detection for Satellite Momentum Wheel Based on Optimized SVM and Huffman-Multi-Scale Entropy

The health status of the momentum wheel is vital for a satellite. Recently, research on anomaly detection for satellites has become more and more extensive. Previous research mostly required simulation models for key components. However, the physical models are difficult to construct, and the simulation data does not match the telemetry data in engineering applications. To overcome the above problem, this paper proposes a new anomaly detection framework based on real telemetry data. First, the time-domain and frequency-domain features of the preprocessed telemetry signal are calculated, and the effective features are selected through evaluation. Second, a new Huffman-multi-scale entropy (HMSE) system is proposed, which can effectively improve the discrimination between different data types. Third, this paper adopts a multi-class SVM model based on the directed acyclic graph (DAG) principle and proposes an improved adaptive particle swarm optimization (APSO) method to train the SVM model. The proposed method is applied to anomaly detection for satellite momentum wheel voltage telemetry data. The recognition accuracy and detection rate of the method proposed in this paper can reach 99.60% and 99.87%. Compared with other methods, the proposed method can effectively improve the recognition accuracy and detection rate, and it can also effectively reduce the false alarm rate and the missed alarm rate.