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1.
从正则系综的基本公式出发,绕开对位形积分的具体计算,结合热力学能态方程,求出了e ̄(-1)<(压缩因子Z)<e的定容高压实际混合气体在任意(T_o,p_o)附近压力与温度的一般解析式,并与实验值进行了对照。应用本文导出的公式在工程热物理方面可减少实验测试的次数,在石化工业中可用来计算环境温度的变化对高压储气罐内压力的影响。 相似文献
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离心压气机实际气体准三元数值计算 总被引:5,自引:1,他引:4
1前言目前,化工用高压离心式压缩机的工质繁多,它们大都为真实气体。针对压缩理想气体而言的流场分析结果,显然不能简单地用来比拟压缩实际气体的流场.在生产和科学研究中,对压气机进行实际气体的性能测试和流场详细测量都比工质使用空气(理想气体)的难度大得多。因此分析比较理想气体和实际气体这两种不同工质的流场,寻找它们之间的内在联系对指导实际气体的设计工作有重要的指导意义。在这方面,文献[1]已做了大量工作,本文采用了一些不同的方法,做了新的尝试。目的是讨论离心式叶轮内理想气体与实际气体流场分析结果之间的差异… 相似文献
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测试温度对nc—Si:H膜光致发光特性的影响 总被引:1,自引:0,他引:1
利用常规等离子体化学气相沉积(PECVD)工艺制备了nc-Si:H膜,并对其光致发光(PL)特性从10-250K温度范围内进行了变温测量,实验结果指出,随着测试温度升高,PL峰值能量发生了54meV的红移,PL强度在T〉80K后呈指数下降趋势,PL峰值能量的红移起因于带隙收缩,而PL强度的减弱则是由于非辐射复合起了主导作用。 相似文献
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李永馨 《光谱学与光谱分析》1994,14(5):9-13
将荧光探针1-苯胺基萘-8-磺酸盐(ANS)加入到乙烯基吡咯烷酮(VP)-醋酸乙烯酯(VAC)共聚物溶液中,共聚物组成分别为FVP=0.84;0.74;0.70;0.55(以乙烯基吡咯烷酮结构单元的分子数表示)。实验结果表明:VP-VAC共聚物对ANS水溶液的荧光强度增强效应与共聚物中乙烯基吡咯烷酮在逻节中的比例有关,其组成为FVP=0.55的共聚物对ANS水溶液有显著的荧光增强效应,相对荧光强度 相似文献
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TBP对部分皂化的DMHPA—正庚烷体系及萃取稀土有机相的影响 总被引:1,自引:0,他引:1
沈玉华 《光谱学与光谱分析》1998,18(3):311-314
研究了部分皂化的二(1甲基庚基)磷酸(DMHPA)磷酸三丁酯(TBP)—正庚烷(C7H16)体系及萃取稀土有机相的聚集状态。结果表明,TBP可以扩大DMHPAC7H16H2O微乳状液形成的区间,并且对萃取有机相的存在状态及水的行为有明显的影响,在一定的条件下有凝胶形成。FTIR光谱分析表明,该类凝胶中DMHPA和TBP与稀土离子以多种形式配位,TBP与DMHPA及水的氢键结合对凝胶网状结构的形成也起了一定的作用。 相似文献
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对Os(Ⅱ)配合物的光致发光过程进行了实验研究.发现将其复合于PVCz基质中时,相对于纯配合物情形,发光强度增强,荧光寿命增长.在PVCz存在的条件下,由于激发能从PVCz到配合物MLCT*态的能量转移,使得MLCT*态的发光强度增强. 相似文献
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Based on Bergeron's theory, a graphical and analytical method has been worked out to determine the dynamic load characteristic and load transients for a time-varying load impedance, pulsed by a lossless transmission line. The analytical solution has been compared with the numerical solution of the network analysis code SCEPTRE. A parametric study for a time-decreasing load function, demonstrated by the example of a vacuum-discharge flash X-ray tube, reveals that the dynamic load characteristic IL[UL(t), U0, Z0, T] and the transients UL(t, U0, Z0, T) and IL(t, U0, Z0, T) are dependent on the diode function ZL(t) as well as on the charging voltage U0 and the characteristics T and Z0 of the line. 相似文献
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《中国科学:物理学 力学 天文学(英文版)》2010,(11)
The possibility of studying D 0-D 0 mixing at a giga-Z linear collider "Z factory" where 10 9 hadronic Z 0 decays can be accumulated is examined.We discuss the sensitivity for the measurements of neutral D mixing parameters.These results are compared to those attainable at B factories.We find that the typical decay length of the neutral D mesons at Z factory is about 10 times larger than that at B factory.In addition,the resolution of the vertex detector of a giga-Z factory is 2-3 times better than that of B factory.The proper time resolution at Z factory is about 20-30 times better than that at B factory.Therefore the determination of the mixing parameters at a giga-Z factory is more precise. 相似文献
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在 1 × N 波分复用/ 解复用器中, N + 1 个自聚焦棒透镜构成了一个1 到 N 的准直系统。自聚焦棒透镜之间的间隔不等, 导致了较大的不均匀的附加耦合损耗。为了使总的平均损耗最低, N + 1 个自聚焦棒透镜的长度应匹配选择。数值计算结果表明, 输入自聚焦棒透镜应比1/4节距稍长Δ Z0 = 20~50 μm , 因 N 而异, 有一上限。 N 个输出自聚焦棒透镜的长度不等, 靠近输入端者比1/4 节距略短, 远端者比1/4 节距略长, 亦因 N 而异。这样匹配使得总的损耗最低, 适用于 N≤8(尤其是 N ≤6) 的情形。 相似文献
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Acosta D Affolder T Albrow MG Ambrose D Amidei D Anikeev K Antos J Apollinari G Arisawa T Artikov A Ashmanskas W Azfar F Azzi-Bacchetta P Bacchetta N Bachacou H Badgett W Barbaro-Galtieri A Barnes VE Barnett BA Baroiant S Barone M Bauer G Bedeschi F Behari S Belforte S Bell WH Bellettini G Bellinger J Benjamin D Beretvas A Bhatti A Binkley M Bisello D Bishai M Blair RE Blocker C Bloom K Blumenfeld B Bocci A Bodek A Bolla G Bolshov A Bortoletto D Boudreau J Bromberg C Brubaker E Budagov J 《Physical review letters》2005,95(5):051801
We present a new search for H0V production, where H0 is a scalar Higgs boson decaying into bb with branching ratio beta, and V is a Z0 boson decaying into e+e-, mu+mu-, or nunu. This search is then combined with previous searches for H0V where V is a W+/- boson or a hadronically decaying Z0. The data sample consists of 106 +/- 4 pb(-1) of pp collisions at square root of s = 1.8 TeV accumulated by the Collider Detector at Fermilab. Observing no evidence of a signal, we set 95% Bayesian credibility level upper limits on sigma(pp --> H0V) x beta. For H0 masses of 90, 110, and 130 GeV/c2, the limits are 7.8, 7.2, and 6.6 pb, respectively. 相似文献
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The evolution of nuclear disintegration mechanisms with increasing excitation energy, from compound nucleus to multifragmentation, has been studied by using the Statistical Multifragmentation Model (SMM) within a micro-canonical ensemble. We discuss the observable characteristics as functions of excitation energy in multifragmentation, concentrating on the isospin dependence of the model in its decaying mechanism and break-up fragment configuration by comparing the A0=200, Z0=78 and A0=200, Z0=100 systems. The calculations indicate that the neutron-rich system (Z0=78) translates to a fission-like process from evaporation later than the symmetric nucleus at a lower excitation energy, but gets a larger average multiplicity as the excitation energy increases above 1.0 MeV/u. 相似文献
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Abazov VM Abbott B Abolins M Acharya BS Adams M Adams T Agelou M Agram JL Ahn SH Ahsan M Alexeev GD Alkhazov G Alton A Alverson G Alves GA Anastasoaie M Anderson S Andrieu B Arnoud Y Askew A Asman B Atramentov O Autermann C Avila C Badaud F Baden A Baldin B Balm PW Banerjee S Barberis E Bargassa P Baringer P Barnes C Barreto J Bartlett JF Bassler U Bauer D Bean A Beauceron S Begel M Bellavance A Beri SB Bernardi G Bernhard R Bertram I Besançon M Beuselinck R Bezzubov VA Bhat PC Bhatnagar V 《Physical review letters》2005,94(16):161801
Using the data collected with the D0 detector at square root(s) = 1.96 TeV, for integrated luminosities of about 180 pb(-1), we have measured the ratio of inclusive cross sections for pp --> Z + b jet to pp --> Z + jet production. The inclusive Z + b-jet reaction is an important background to searches for the Higgs boson in associated ZH production at the Fermilab Tevatron collider. Our measurement is the first of its kind, and relies on the Z --> e+ e- and Z --> mu+ mu- modes. The combined measurement of the ratio yields 0.021+/-0.005 for hadronic jets with transverse momenta pT > 20 GeV/c and pseudorapidities absolute value(eta) < 2.5, consistent with next-to-leading-order predictions of the standard model. 相似文献
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Wen XG 《Physical review letters》2003,90(1):016803
We find all the exact eigenstates and eigenvalues of a spin-1/2 model on square lattice: H=16g Sum S(y)(i)S(x)(i + empty set x)S(y)(i + empty set x + empty set y)S(x)(i + empty set y). We show that the ground states for g < 0 and g > 0 have different quantum orders described by Z2A and Z2B projective symmetry groups. The phase transition at g = 0 represents a new kind of phase transition that changes quantum orders but not symmetry. Both the Z2A and Z2B states contain Z2 lattice gauge theories at low energies. They have robust topologically degenerate ground states and gapless edge excitations. 相似文献
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Trischuk W de Troconiz JF Truitt S Tseng J Turini N Ukegawa F Valls J Vejcik S Velev G Vidal R Vilar R Vologouev I Vucinic D Wagner RG Wagner RL Wahl J Wallace NB Walsh AM Wang C Wang CH Wang MJ Watanabe T Waters D Watts T Webb R Wenzel H 《Physical review letters》2000,84(5):835-840
We present the results of a search for pair production of a fourth-generation charge -1 / 3 quark (b(')) in sqrt[s] = 1.8 TeV p&pmacr; collisions using 88 pb(-1) of data obtained with the Collider Detector at Fermilab. We assume that both quarks decay via the flavor-changing neutral current process b(')-->bZ(0) and that the b(') mass is greater than m(Z)+m(b). We studied the decay mode b(')b(');-->Z(0)Z(0)b&bmacr; where one Z0 decays into e(+)e(-) or &mgr;(+)&mgr;(-) and the other decays hadronically, giving a signature of two leptons plus jets. An upper limit on the sigma(p&pmacr;-->b(')b(');)x[B(b(')-->bZ(0))](2) is established as a function of the b(') mass. We exclude at 95% confidence level a b(') quark with mass between 100 and 199 GeV/c(2) for B(b(')-->bZ(0)) = 100%. 相似文献
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Saxton OH Schalk T Schumm BA Schwiening J Serbo VV Shapiro G Sinev NB Snyder JA Staengle H Stahl A Stamer P Steiner H Su D Suekane F Sugiyama A Suzuki A Swartz M Taylor FE Thom J Torrence E Usher T Va'vra J Verdier R Wagner DL Waite AP Walston S 《Physical review letters》2000,85(24):5059-5063
We present the first direct measurement of A(s), the parity-violating coupling of the Z0 boson to the strange quark, using approximately 550 000 e(+)e(-)-->Z0-->hadrons events recorded by the SLC Large Detector with a polarized e(-) beam. We tagged Z0-->s&smacr; events by the absence of B or D hadrons and the presence in each hemisphere of a high momentum K+/- or K(0)(s). Fitting the polar angle distributions of the strangeness-signed thrust axis gave A(s) = 0.895+/-0.066(stat)+/-0.062(syst). The analyzing power and uu+d&dmacr; background were constrained using the data, greatly reducing any model dependence. 相似文献
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We give a multiresolution partition of pure point parts of diffraction patterns of one-dimensional aperiodic sets. When an aperiodic set is related to the Golden Ratio, denoted by
, it is well known that the pure point part of its diffractive measure is supported by the extension ring of
, denoted by
. The partition we give is based on the formalism of the so called
-integers, denoted by
. The set of
-integers is a selfsimilar set obeying
,
. The pure point spectrum is then partitioned with respect to this Russian doll like sequence of subsets
. Thus we deduce the partition of the pure point part of the diffractive measure of aperiodic sets.Received: 24 March 2004, Published online: 12 July 2004PACS:
61.44.Br Quasicrystals - 61.10.Dp Theories of diffraction and scattering 相似文献