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1.
半导体带电粒子探测器的研制及其在空间物理中的应用   总被引:1,自引:0,他引:1  
阐述了空间辐射环境监测的意义,描述了半导体带电粒子探测器的研制及由其组成的望远镜系统在空间物理中的应用,并给出了用此探测器在卫星上进行地球辐射环境监测、太阳质子事件和地磁暴探测的部分结果.  相似文献   
2.
张金霞  高恩伟 《东北数学》2003,19(2):115-118
Let R be a commutative ring without nil-factor. In this paper, we discuss the problem of quasi-valuation ring presented in the reference “Wang Shianghaw, On quasi-valuation ring, Northeast People‘s Univ. Natur. Sci. J., (1)(1957), 27-40”,when the quotient field of R is an algebraic number field or an algebraic function field, and we obtain a characterization of quasi-valuation rings.  相似文献   
3.
设Q为有理数域,令φ为由奇素数p生成的有理数域Q的p-adic赋值,R为与其相对应的赋值环,(p)为R的极大理想(素理想).本文用扩张平移的方法讨论了lm)(μ∈R)中的分解问题,并完全解决了该问题.素理想(p)在Q的lm次根扩张Q(μ1  相似文献   
4.
A novel Micro-pattern gaseous detector (MPGD), thick GEM with electrodes made of a resistive material (RETGEM) is presented. In this paper we mainly investigate the energy resolution of a RETGEM in Ar+CO2 with different gas mixtures. The results indicate that an energy resolution 30% in single and double mode can be obtained. The existence of an optimum energy resolution is discussed.  相似文献   
5.
介绍了微型网状结构的气体探测器一维位置编码读出的基本原理和实现方法。设计了一块灵敏面积为10 cm×10 cm的一维位置编码PCB读出电极。测试表明: 感应读出是可行的, 电荷按1∶2分配最为理想; 利用55Fe放射源X射线通过200 μm狭缝对准读出电极PCB板的正面中任意一条, 位置编码读出能很好地再现源所在狭缝的位置。针对其局限性, 提出了一维位置分组编码读出技术, 以解决相邻多条同时点火的情况。使用该读出技术, 使一维读出电子学路数节省量达到75%以上。The basic principles and implementation of one dimensional position encoding read out for MICROMEGAS have been introduced in this paper. A 10 cm×10 cm prototype of one dimensional position encoding read out electrode based on printed circuit board was designed. Preliminary test indicates that the induction read out is feasible and the ideal charge distribution is 1∶2. X rays emitted from 55Fe source were collimated to one of strips on the read out electrode through a slit of 200 μm, position decoding well reproduced the position of the 55Fe source. For its limitations, we have proposed a one dimensional grouped position encoding read out technique to address a neighboring strips simultaneously fired situation. The amount of read out electronics is very easy to approach a obduction of 75% with position encoding read out technology.  相似文献   
6.
A new 1D chain coordination polymer [Cd(dpq)(ox)0.5Cl]n(1) (dpq=dipyrido[3,2-d:2′,3′-f]quinoxaline and ox=oxalate) has been hydrothermally synthesized and structurally characterized by elemental analysis, IR and single crystal X-ray diffraction analysis. Compound 1 (CdClC15H8N4O2): monoclinic, space group P21/c, a=0.854 04(5) nm, b=2.094 90(13) nm, c=0.839 22(5) nm, Z=4, V=1.438(15) nm3, Mr=424.11, Dc=1.959 g·cm-3, F(000)=828.0, μ=1.719 mm-1, S=1.028, the final R=0.025 8 and wR=0.057 5. The crystal structure analysis indicates that the cadmium ion is coordinated by two oxygen atoms from a oxalate, two chelating nitrogen atoms from a dpq molecule and two Cl- anions. The adjacent Cd(Ⅱ) ions are linked by Cl- anions and oxalate ligands in alternate sequence to form a 1D chain coordination polymer and the adjacent chains are further connected by π-π stacking interactions to form a 2D supramolecular network. Moreover, the title compound exhibits blue emission in the solid state at room temperature. CCDC: 680748.  相似文献   
7.
素理想(P)在Q(μ1/l)中的分解   总被引:6,自引:0,他引:6  
设 Q为有理数域 ,令φ为素数 p生成的有理数域 Q的 p- adic赋值 ,r为与其相对应的赋值环 ,(p)为 r的极大理想 (素理想 ) .本文用扩张平移的方法讨论了素理想 (p)在 Q的 l次根扩张 Q(μ1 / l) (μ∈ r)中的分解问题 ,并完全解决了该问题 ,包含了文 [1 ]的相关结果  相似文献   
8.
简单介绍了重离子治癌的原理, 叙述了一种用于重离子治癌的大面积平行板雪崩计数器, 它主要由入射窗、 x位置栅极、 中心阳极、 y位置栅极和出射窗组成. 使用C3F8气体, 气压700 Pa, 阳极电压为700 V, 两阴极接地, 电子学成形时间常数为2 μs, 测试得到的位置分辨修正后为0.54 mm(FWHM). 通过与国内外同类装置比较, 认为这一分辨已经满足了重离子治癌装置的要求. he principle of the heavy ion therapy is introduced in this article. In order to precisely determine the irradiation profiles and positions of scanned heavy ion beams, we developed a large area parallel plate avalanche counter(PPAC). The detector consists of one anode, two cathodes and two windows with 250 mm×250 mm active area . It was measured at an anode voltage of 700 V and with flowing C3F8 gas at the pressure of 700 Pa. A position resolution of 0.54 mm by correction was obtained with an α source. As compared with the similar devices, we consider the position resolution of the PPAC can satisfy the requirement of the facility of heavy ion therapy.  相似文献   
9.
研制了一种新型的带有阻抗性电极的TGEM——RETGEM(Thick GEM with Resistive Electrodes)探测器, 阻抗性电极可以有效地保护探测器和前端电子学免于偶尔放电的损伤。 对RETGEM探测器进行了初步测试, 其中包括计数率、能量分辨、增益以及打火率。 结果表明, 探测器达到了设计的基本要求。 In this study we present preliminary results from a new detector: a thick gaseous electron multiplier(GEM) with resistive electrodes. The resistive electrodes protect the detector and the front end electronics from damage by occasional discharges. In different gas mixtures, we test Thick GEM with Resistive Electrodes(RETGEM) detector for the first time, including counting rate, energy resolution, effective gain, and discharge probability. The results can satisfy the basic demand of RETGEM detector design.  相似文献   
10.
关于一种相对域的素理想分解   总被引:4,自引:1,他引:3  
主要讨论了代数域的扩张平稳之前与扩张平移之后的分解各间的关系问题,以及素理想分解问题,改进了文「3」的结果。  相似文献   
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