陶瓷/VDF-TrFE 0-3型铁电复合物的三阶非线性介电系数

在自建的非线性介电测试装置上测得了Ｐ笔ＶＤＦ－ＴｒＦＥ共聚物形成的０－３型铁电复合物厚片的三阶非线性介电系数ε３。研究发现,三种复合物的ε３都随陶瓷组分含量的上升而增大,测试场强升高,测得的ε３值减小,但对高陶瓷含量（Φ〉０．０４）的ＢＴ／ＶＤＦ－ＴｒＦＥ和ＰＺ／ＶＤＦ－ＴｒＦＥ复合物则在６ＭＶ／ｍ场强下出现极小值,二相都被预极化的复合物小于仅陶瓷相被预极化的ε３值,ＰＺＴ／ＶＤＦ－ＴｒＦＥ复合物     

时间分辨傅里叶变换红外光谱法研究聚偏氟乙烯的晶变

本文用时间分辨傅里叶变换红外光谱（ＴＲ－ＦＴＩＲＳ）法研究了聚偏氟乙烯（ＰＶＤＦ）的晶型转变，并认５０８ｃｍ＾－１峰的增强和５２８ｃｍ＾－１峰的减弱表示ａ晶型向β晶型的转变，瞬变的初期时间约５ｍｓ，在晶型转变中伴随有“磁滞回线”的非线性效应。     

碳氢碳氟表面活性剂混合胶束的NMR和ESR研究

用ＮＭＲ，ＥＳＲ和表面张力测量研究了３－十二烷氧基－２－羟丙基磺酸钠（ＳＤＥＨＳ）与全氟辛酸钠（ＳＰＦＯ）混合溶液微环境性质，表面张力测定表明长链烷基磺酸盐中嵌入羟丙基后，其表面活性提高，而与ＳＰＦＯ混合溶液的表面活性高于单一的ＳＤＥＨＳ和ＳＰＦＯ，ＮＭＲ和ＥＳＲ研究表明，ＳＤＥＨＳ的碳氢链与ＳＰＦＯ的碳氟链之间有强烈的相互作用，ＳＤＥＨＳ与ＳＰＦＯ形成混合胶束，混合胶束“界面”的微观粘度较ＳＤＥ     

二氟硅烯与乙烯环加成反应的理论研究

用ＲＨＦ／６－３１Ｇ＾＊解析梯度方法研究了单重态二氟硅与乙烯环加成反应的机理,并用统计热力学方法和过渡态理论计算了该反应温度下的热力涵 数的变化和动力学性质。结果表明,此反应历程由两组成：（１）二氟硅烯与乙烯生成了一中间配合物,是一无势垒的放热反应;     

富电子膦硫混配钴簇合物Co6S8[P（OCH3）3]6的电化学研究

利用循环伏安法研究了膦硫混配原子簇化合物Ｃｏ６Ｓ８「Ｐ（ＯＣＨ３）３」６的电化学行为,结果表明Ｃｏ６Ｓ８「Ｐ（ＯＣＨ３）３」６在ＣＨ２Ｃｌ２训可观察到三个可逆氧化还原过程,其电子转移过程为;Ｃｏ６Ｓ８「ｐ（ｏｃｈ３）３」６－＝＾（－Ｅ,＋Ｅ）Ｃｏ６Ｓ８「Ｐ（ＣＯＨ３０３」６ｙ０＝（＾－ｅ,＋ｅ）Ｃｏ６Ｓ８「Ｐ（ＯＣＨ３）３」６＾＋＝＾（－ｅ,＋ｅ）Ｃｏ６Ｓ８「Ｐ（ＯＣＨ３）３」６＾２＋并探讨了其电     

VDF（52）／TrFE（48）铁电共聚物的非晶介电弛豫

用液氮淬火和热处理方法制得结晶度相差较大的铁电共聚物ＶＤＦ（５２）／ＴｒＦＥ（４８）试样。介导弛豫研究提示室温以下共聚物的频率谱由低频和高频两部分组成。低频部由非晶区被冻结分子链段的微布郎运动贡献。符合ＷＬＦ方程；高频部由晶区分子链段较小尺度的局域运动产生，遵从Ａｒｒｈｅｎｉｕｓ规律。分峰拟合结果得到共聚物的玻璃化转变温度为－２４℃，局域弛豫活化能为４６．１ｋＪ／ｍｏｌ．     

聚(偏氟乙烯-三氟乙烯)纳米薄膜极化反转与疲劳特性

采用旋涂法制备了厚度为140 nm的聚(偏氟乙烯-三氟乙烯)[P(VDF-TrFE)]纳米薄膜, 研究了不同退火温度以及环境相对湿度对薄膜的极化反转和疲劳性能的影响. 运用X射线衍射仪、扫描电子显微镜和傅里叶变换红外光谱仪等测试技术对薄膜的微结构进行了表征. 实验结果表明, 通过不同温度的退火处理, P(VDF-TrFE)铁电薄膜的结晶度随着退火温度的升高而不断提高, 并且一定的温度范围内的退火处理可以提高薄膜的极化性能; 此外, P(VDF-TrFE) 铁电薄膜性能还表现出一定的环境湿度的敏感特性, 这与薄膜的物理性能和结构特点密切相关; P(VDF-TrFE)铁电薄膜在不同的环境湿度条件下 表现出较好的电学特性, 其漏电流均保持在10 ^-7A/cm² 的较低水平. 本工作揭示了再退火过程对薄膜的极化反转速度和疲劳恢复特性的影响, 并结合薄膜二次疲劳结果, 探讨了薄膜可逆的内部疲劳恢复特性机理.     

含MoFe3S4单元的μ2—OR或μ2—SR桥联双类立方烷簇合物的红？…

对下列含ＭｏＦｅ３Ｓ４单元的μ２－ＯＲ或μ２－ＳＲ桥联双类立方烷簇合物的红外光谱进行了研究：（Ｅｔ４Ｎ）３「Ｍｏ２Ｆｅ６Ｓ８Ｃｌ６（ＯＭｅ）３」（１）,（Ｅｔ４Ｎ）３「Ｍｏ２Ｆｅ６Ｓ８（ＳＰｈ）６（ＯＭｅ）３」（２）,（Ｂｕ４Ｎ）３「Ｍｏ２Ｆｅ６Ｓ８（ＳＰｈ）６（ＯＭｅ）３」（３）（Ｅｔ４Ｎ）３「Ｍｏ２Ｆｅ６Ｓ８（ＳＢｕ＾ｔ）６（ＯＭｅ０３」（４）ｍ,（Ｅｔ４Ｎ）３「Ｍｏ２Ｆｅ６Ｓ８（ＳＰｈ）９」     

铂Hugoniot曲线的Ab initio计算

对于一个原子平均体积为Ｖ,温度为Ｔ的热力学系统,体系的Ｈｅｌｍｂｏｌｔｚ自由能可以写为Ｆ（Ｖ,Ｔ）＝Ｅｃ（Ｖ）＋Ｆｉｏｎ（Ｖ,Ｔ）＋Ｆｅｌ（Ｖ,Ｔ）＋Ｆｍａｎ（Ｖ,Ｔ）其中Ｅｃ为０－Ｋ冷能。对于其中的电子热激发贡献Ｆｅｌ,目前流行的有三种计算方案,即：Ｍｏｒｕｚｚｉ的Ｄｅｂｙｅ－Ｇｒｕｅｎｅｉｓｅｎ方案、Ｍｏｒｉａｒｔｙ的ＭＧＰＴ方案和Ｗａｓｓｅｒｍａｎ的ＣＥＬＬ模型方案。Ｄｅｂｙｅ－Ｇｒｕｅｎｅ     

乙烯基吡咯烷酮—醛酸乙烯酯共聚物对1—苯胺基萘—8—磺酸盐水溶液的荧光...

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     

Boson realization of YangiansY(sl(2)) andY(sl(3))

Studying the algebraic structure of the YangiansY(sl(2)), andY(sl(3)) we present their boson realizations. In the case ofY(sl(2)) we give the realization by using 1-canonical boson pair and two parameters and in theY(sl(3)) with 2-canonical boson pairs, two parameters and subalgebrasl(2). Substituting the realization ofU(sl(2)), we can obtain the pure boson realization by 3-canonical pairs and three parameters.Presented at the 4th Colloquium Quantum Groups and Integrable Systems, Prague, 22–24 June 1995.     

(Fe0.03Ni0.97)8(Si0.79P0.21)3的等温状态方程研究

 采用固态高温烧结反应方法,成功合成出了陨硅镍铁石样品(Fe_0.03Ni_0.97)₈(Si_0.79P_0.21)₃。X射线衍射结果表明,合成样品的结构为R3'c,对应的晶胞参数为a=b=0.663 8(1) nm,c=3.789 2(2) nm,V=1.446 15(6) nm³。在室温下,对样品进行原位高压X射线衍射研究,实验最高压力达到21.3 GPa,随着压力的升高,晶胞体积逐渐减小,但并没有观察到结构相变。利用Birch-Murnaghan状态方程对体积与压力的关系进行拟合,获得常温常压下的体积V₀=1.441 4(24) nm³,体积模量K₀=220(7) GPa。晶轴与压力的关系利用Murnaghan状态方程拟合,获得a轴和c轴的模量分别为K_a=257(9)和K_c=165(4),c轴较a轴容易压缩。     

Thermolumineszenzdosimetrie (TLD) (Zusammenfassender Bericht

Die Thermolumineszenzdosimetrie (TLD) mit Speichcrphosplioren hat in der letzten Jahren zunehmende Anwendung in der klinischen Praxis und bei der Überwaehung beruflich strahlenexponierter Personen gefunden.

Die in den Jahren 1908/09 crsehienenen Monographien in englischer, russischer und deutseher Sprache [1—3] und drei Bibliographien [4 — 6] spiegeln den hohen Entwicklunggstand dieses Verfahrens der Festkörperdosimetrie bis Ende 1907 wider und erleichtern das Auffinden älterer Literatur.

Seitdem ist eine große Anzahl neuer Beiträge zur Thermolumineszenzdosimetrie erschienen. Insbesondere beinhalten die Berichte der 1908 und 1971 stattgefundenen zweiten und dritten "Internationalen Konferenz über Lumineszenzdosimetrie" viele wertvolle Arbeiten. Ziel des vorliegenden Beriehtes ist es, eine knappe Übersicht über die im Zeitraum von 1908 bis 1972 erzieltcn Fortschritte auf dem Gebiet der Dosimetrie ionisierender Strahlung mit Speicherphosplioren zu geben. Dabei erfolgt eine Beschränkung auf praktische Fragen der Thermolumineszenzdosimetrie. Die Behandlung kinetiseher Modellvorstellungen der Thermolumineszenz ist nicht Gegenstand dieser Veröffentliehun".     

Measurement of G(E(p))/G(M(p)) in e(-->)p---> e(-->)p to Q(2) = 5.6 GeV(2)

The ratio of the electric and magnetic form factors of the proton G(E(p))/G(M(p)), which is an image of its charge and magnetization distributions, was measured at the Thomas Jefferson National Accelerator Facility (JLab) using the recoil polarization technique. The ratio of the form factors is directly proportional to the ratio of the transverse to longitudinal components of the polarization of the recoil proton in the elastic e(-->)p---> e(-->)p reaction. The new data presented span the range 3.5< Q(2)< 5.6 GeV(2) and are well described by a linear Q(2) fit. Also, the ratio sqrt[Q(2)] F(2(p))/F(1(p)) reaches a constant value above Q(2) = 2 GeV(2).     

Recording of second-harmonic index gratings in photorefractive (K(0.5) Na(0.5))(0.2) (Sr(0.75) Ba(0.25))(0.9) Nb(2)O(6) crystals

We propose and demonstrate a novel method for recording second-harmonic volume index gratings in photorefractive crystals. The fundamental component of the index grating is eliminated by means of a pi -phase shifted double-exposure process that uses the Mach-Zehnder interferometric technique. Experimental results for (K(0.5) Na(0.5)) (0.2)(Sr> (0.75)Ba (0.25))(0.9)Nb (2)O(6) crystals are presented and discussed.     

Dual nature of the electronic structure of (La(2--x--y)Nd(y)Sr(x))CuO(4) and La(1.85)Sr(0.15)CuO(4).

High resolution angle-resolved photoemission measurements have been carried out on (La(1.4--x)-Nd(0.6)Sr(x))CuO(4), a model system with static one-dimensional (1D) charge ordering (stripe), and (La(1.85)-Sr(0.15))CuO(4), a high temperature superconductor (T(c) = 40 K) with possible dynamic stripes. In addition to the straight segments near ( pi,0) and ( 0,pi) antinodal regions, we have identified the existence of spectral weight along the [1,1] nodal direction in the electronic structure of both systems. This observation of nodal state, together with the straight segments near antinodal regions, reveals the dual nature of the electronic structure of stripes due to the competition of order and disorder.     

Theoretical Study of the Collision-Induced Double Transition CO(2) (nu(3) = 1) + N(2) (nu(1) = 1) <-- CO(2) (nu(3) = 0) + N(2) (nu(1) = 0) at 296 K

A procedure is presented for the calculation of the double vibrational collision-induced absorption CO(2) (nu(3) = 1) + N(2) (nu(1) = 1) <-- CO(2) (nu(3) = 0) + N(2) (nu(1) = 0) on the basis of quantum lineshapes computed using an isotropic potential and dipole-induced dipole functions. The linestrengths and energies of the vibration-rotation transitions are treated explicitly for N(2), utilizing the HITRAN database for CO(2). The theoretical absorption profile is compared to recent experimental results. By narrowing the width of the individual lines contributing to the overall absorption profile relative to their values determined for N(2)-N(2) collision-induced absorption, excellent agreement between theory and experiment is obtained. Copyright 2000 Academic Press.     

First Observation of the nu(17)-nu(4) Difference Bands of Diborane (10)B(2)H(6) and (11)B(2)H(6)

An analysis of the nu(17)-nu(4) difference bands near 800 cm(-1) of two isotopic species, (10)B(2)H(6) and (11)B(2)H(6), of diborane has been carried out using infrared spectra recorded with a resolution of ca. 0.003 cm(-1). In addition, the nu(17) band of (10)B(2)H(6) has been recorded and assigned. Since this band in (11)B(2)H(6) had already been studied (R. L. Sams, T. A. Blake, S. W. Sharpe, J.-M. Flaud, and W. J. Lafferty, J. Mol. Spectrosc. 191, 331-342 (1998)), it was possible to derive precise energy levels and Hamiltonian constants for the 4(1) vibrational states of both isotopic species. Copyright 2000 Academic Press.     

Semi-constant-time HMSQC (SCT-HMSQC-HA) for the measurement of (3)J(H(N))(H(alpha)) couplings in (15)N-labeled proteins

A simple method for accurately measuring (3)J(H(N))(H(alpha)) coupling constants in (15)N-labeled proteins is described. This semi-constant-time HMSQC-HA experiment combines the rapidity and convenience of the recently introduced CT-HMQC-HA scheme (Postingl and Otting, J. Biomol. NMR 12, 319-324 (1998)) with the high resolution and robustness of the HSQC experiment. The proposed method is demonstrated for the 76-residue human ubiquitin and Saccharopolyspora erythraea calerythrin (176 residues). Our results imply that the SCT-HMSQC-HA experiment is suitable also for proteins with less favorable NMR properties due to its good resolution and sensitivity.