光通信用1.55微米InGaAsP/InP DH激光器中的0.95微米发光和俄歇复合

Submitted by zhangdi (zhangdi@red.semi.ac.cn) on 2009-04-13T11:45:31Z

1.55μm InGaAsP/InP DH激光器中的0.95μm发光带与Auger复合

于2010-11-23批量导入

High-spin level structure in Mo-94,Mo-95

High-spin level structures of 94,95Mo have been reinvestigated via the 16O(82Se, xnγ)94,95Mo(x = 4, 3) reactions at E(82Se) = 460 MeV. The previously reported level schemes of these two nuclei have been largely modified up to ∼11 MeV in excitation energy due to identifications of some important linking transitions. Shellmodel calculations have been made in the model space of π(p1/2, g9/2, d5/2)4 and ν(d5/2, s1/2, d3/2, g7/2, h11/2)2(3) and compared with the modified level schemes. The structures of the newly assigned high-spin states in 94,95Mo have been discussed.

Structural stability of C-60 films under the bombardment of 1.95 GeV Kr ions

The structural stability of C-60 films under the bombardment of 1.95 GeV Kr ions is investigated. The irradiated C-60 films were analyzed by Fourier Transform Infrared (FTIR) spectroscopy and Raman scattering technique. The analytical results indicate that the irradiation induced a decrease of icosahedral symmetry of C-60 molecule and damage of C-60 films; different vibration modes of C-60 molecule have different irradiation sensitivities; the mean efficient damage radius obtained from experimental data is about 1.47 nm, which is in good agreement with thermal spike model prediction.

Y_(1.95-x)Gd_xSiO_5:Eu_(0.05)的真空紫外光谱

利用高温固相法合成了 Ｙ１．９５－ｘＧｄｘＳｉＯ５：Ｅｕ０．０５（ｘ＝０．６ｍｏｌ％）荧光体。结构测定表明所合成的荧光体为单斜晶系的Ｘ２型Ｙ２ＳｉＯ５相，空间群为Ｂ２／ｂ。真空紫外光谱表明：随着Ｇｄ３＋含量的增加，在１９２ｕｍ附近，出现了Ｇｄ＋的激发峰，且此峰的强度随着Ｇｄ３＋含量的增加而增大；同时位于１５０～１８５ｎｍ之间的基质吸收带的强度也增大；而位于２００～３００ｎｍ之间的Ｅｕ的电行迁移带的强度却随着Ｇｄ３＋含量的增加而降低。

Laser light scattering studies of soluble high-performance polyimides: Solution properties and molar mass distributions

Two soluble high-performance polyimides, poly(BCPOBDA/DMMDA) and poly(ODPA/DMMDA), in CHCl3 at 25 degrees C have been studied using laser light scattering. We found that the z-average radius of gyration ([R(g)]) can be scaled to the weight-average molecular weight (M(w)) as [R(g)] (nm) = 4.95 x 10(-2)M(w)(0.52) and [R(g)] (nm) = 1.25 x 10(-2)M(w)(0.66) respectively for poly(BCPOBDA/DMMDA) and poly(ODPA/DMMDA), indicating that poly(ODPA/DMMDA) in CHCl3 at 25 degrees C has a more extended chain conformation than poly(BCPOBDA/DMMDA). Using the wormlike chain model approach, we found that the Flory characteristic ratios (C*) of poly(BCPOBDA/DMMDA) and poly(ODPA/DMMDA) are similar to 20 and similar to 31, respectively, indicating that both of them have a slightly extended chain conformation in comparison with typical flexible polymer chains, such as polystyrene, whose C-infinity is similar to 10. A combination of the weight-average molar mass (M(w)) with the translational diffusion coefficient distributions (G(D)) has led to D (cm(2)/s) = 3.53 x 10(-4)M(-0.579) and D (cm(2)/s) = 4.30 x 10(-4)M(-0.613) respectively for two soluble high-performance polyimides, poly(BCPOBDA/DMMDA) and poly(ODPA/DMMTA), in CHCl3 at 25 degrees C. Using these two calibrations, we have successfully characterized the molar mass distributions of the two polyimides from their corresponding G(D)s. The exponents of these two calibrations further confirm that both of the polyimides have a slightly extended coil chain conformation in CHCl3. The chain flexibility difference between these two polyimides has also been discussed.

La_(0.95)Pb_(0.05)F_(2.95)气敏性质的研究

本文研究了“Bi(BiF_3~-)/La_(0.95)Pb_(0.05)F_(2.95)/Pt”元件的气敏性质。元件的电动势与氧分压对数呈线性关系,温度升高,响应时间变短。20℃,在所测的范围内,电动势与空气中氢分压呈对数关系:E=E_0-961gPH_2(mV);敏感电极反应归结为局域电流或称作混合电势机理。元件对空气中1000Pa 氢气的90%响应时间仅用15S。元件对 CO 也有一定的敏感性能,但对甲烷、丁烷、乙炔等不具敏感性能。

Ce_(0.95)Ca_(0.05)F_(3-x)固体电解质氧传感器的研究

本文研究了Ce_(0.95)Ca_(0.05)F_(3-x)固体电解质及其氧传感器的制备和性质。在150℃时,Po_2在10~(-2)～10~(-1)MPa范围内传感器件的电位变化正比于Po_2的对数值。同时研究了不同参比电极和敏感电极对传感性能的影响。以Bi+BiF_3为参比电极时,EMF值稳定较快;当Pd作为敏感电极时,传感元件的响应较快;以RuO_2作敏感电极时,传感器件较灵敏。文章还讨论了敏感机理。

Cys-92, Cys-95, and the C-terminal 12 residues of the Vibrio harveyi ferric uptake regulator (Fur) are functionally inessential

Ferric uptake regulator (Fur) is a global regulator involved in multiple aspects of bacterial life. The gene encoding the Vibrio harveyi Fur (Fur(vh)) was cloned from a pathogenic V. harveyi strain isolated from diseased fish. Furvh shares 77% overall sequence identity with the Escherichia coli Fur (Fur(Ec)) and could complement a mutant of Fur(Ec). Like Fur(Ec), Fur(Vh), possesses two cysteine residues at positions 92 and 95, yet unlike Fur(Ec), in which these cysteine residues constitute part of the metal ion coordination site and hence are vital to the repressor activity, C92 and C95 of Fur(Vh) proved to be functionally inessential. Further study identified a Vibrio Fur signature sequence, which is preserved in all the ten Vibrio Fur proteins that have been discovered to date but in none of the non-vibrio Fur proteins. Site-directed and random mutation analyses of the signature residues, the cysteine residues, and seven highly charged amino acid residues indicated that D9, H32, C137, and K138 of Fur(vh) are functionally important but D9, C137, and K138 can be replaced by more than one functional substitutes. Systematic deletion analysis demonstrated that the C-terminal 12 residues of Fur(Vh) are functionally inessential. These results (i) indicated that the activation mechanism, or certain aspects of which, of Fur(Vh) is possibly different from that of Fur(Ec); and (ii) suggested that it is not very likely that the C-terminal 12 residues play any significant role in the activation or stability of Fur(Vh); and (iii) provided insights into the potential function of the local structure involving C137 and K138.

栉孔扇贝和海湾扇贝免疫防御特性的比较研究

贝类养殖作为我国传统的海水养殖产业，在我国沿海地区的经济发展中起重要作用。但由于近年来养殖扇贝病害的不断发生，不仅造成了巨大的经济损失，而且直接威胁到现有养殖产业的生存和发展。目前认为，机体抗病能力的下降是发生流行性死亡的主要原因之一。因此，深入研究扇贝免疫防御特性，能更好地了解和解决贝类养殖中的病害问题。本文比较了健康状态和重金属污染以及高温胁迫下海湾扇贝和栉孔扇贝部分免疫指标的变化，并对同龄不同大小的栉孔扇贝的部分免疫指标进行了比较，以期更好的了解贝类的防御机制，为扇贝病害防治提供资料。研究结果如下: 用流式细胞仪技术对血细胞死亡率、细胞吞噬率和呼吸爆发进行了测定，发现健康状态下两种扇贝的细胞死亡率相差不大，海湾扇贝为4.83%，栉孔扇贝为4.95%；细胞吞噬率差异显著(P<0.05)，海湾扇贝为26.73%，栉孔扇贝为19.89%；呼吸爆发的基础值相差也不大，海湾扇贝为1.94，栉孔扇贝为1.56。另外用免疫化学方法对健康状态下栉孔扇贝和海湾扇贝血淋巴和肝胰腺中SOD、ACP活性和MDA含量也进行了测定与比较。发现在血淋巴和肝胰腺中，两种扇贝SOD活性均存在显著差异(P<0.05)，其中海湾扇贝分别为995.43和113.99，栉孔扇贝分别为446.64和40.6；血淋巴和肝胰腺中ACP活性差异显著(P<0.05)，海湾扇贝分别为90.19和432.36，栉孔扇贝分别为73.26和146.63；血淋巴中和肝胰腺中MDA含量差异不显著(P>0.05)，海湾扇贝分别为3.37和92.46，栉孔扇贝分别为2.17和28.96。实验结果说明，海湾扇贝对细菌等异物的吞噬和杀灭能力以及机体自身的抗氧化能力高于栉孔扇贝，这为海湾扇贝比栉孔扇贝具有更高的抗逆性提供了证据。 用相同的方法对不同浓度(0, 0.2, 0.3, 0.5 mg L-1) Pb2+溶液浸泡后的栉孔扇贝和海湾扇贝的血细胞死亡率、细胞吞噬率和呼吸爆发进行了检测，同时测定了Pb2+处理后肝胰腺中SOD、ACP活性和MDA含量的变化。结果表明，栉孔扇贝的血细胞死亡率与对照组相比有上升趋势，且随着Pb2+浓度的增加而显著增加，而海湾扇贝在相同条件Pb2+的胁迫下，血细胞的死亡率明显低于栉孔扇贝。栉孔扇贝各实验组细胞吞噬率均低于对照组，而海湾扇贝在低浓度的Pb2+浸泡后，细胞的吞噬率与对照组相比有所降低，但随着浓度的继续增加，细胞的吞噬率反而上升，甚至略高于对照组。栉孔扇贝血细胞的呼吸爆发在Pb2+胁迫后较对照组有所升高，但随着浓度的增加，呼吸爆发有下降的趋势，而海湾扇贝的呼吸爆发随着Pb2+浓度的增加而显著增加。对两种扇贝体液免疫指标的测定发现，各实验组SOD的活性均比对照组高，且海湾扇贝的SOD活性高于栉孔扇贝；随着Pb2+浓度的增加，各实验组ACP的活性一直呈上升趋势，且海湾扇贝的ACP活性也高于栉孔扇贝；Pb2+处理后MDA的含量均显著增加，其中栉孔扇贝MDA含量的增幅明显高于海湾扇贝。该结果说明，Pb2+对两种扇贝的免疫系统都有一定的影响，但相同剂量的Pb2+对两种扇贝的毒害程度不同，海湾扇贝对Pb2+的耐受性似乎高于栉孔扇贝。 对海湾扇贝和栉孔扇贝的升温刺激实验发现，当养殖水体的温度从18℃缓慢升高到30℃后，栉孔扇贝在第三天开始出现大量死亡现象，而海湾扇贝未出现死亡。因而本文只对升温前后的海湾扇贝进行了细胞死亡率、吞噬率和呼吸爆发的测定和比较。结果发现，与升温前相比，血细胞的死亡率在温度升高后略有增加，但差异不显著(P>0.05)；而细胞吞噬率在温度升高后显著下降；通过对呼吸爆发积聚的活性氧（Reactive Oxygen Species，ROS）的测定发现，升温后血细胞的ROS含量显著高于升温前(P<0.05)。该结果表明，高温会影响血细胞的功能，使机体的免疫防御能力下降，从而导致病害的发生。 另外，本文对同龄不同大小的栉孔扇贝的血细胞吞噬率以及血淋巴和肝胰腺中SOD、ACP活性和MDA含量进行了测定与比较。结果发现: 小扇贝的血细胞吞噬率略高于大扇贝，分别达到了22.82和20.96；在血淋巴及肝胰脏中，两组扇贝SOD酶的活性均差异显著(P<0.05)，小扇贝分别为613.88和102.01，大扇贝分别为356.15和50.22；血淋巴中小扇贝ACP的活性极显著的高于大扇贝(P<0.01)，分别为44.3和2.91，但肝胰腺中大扇贝和小扇贝ACP的活性相差不大，大扇贝为455.75，小扇贝为485.33；大扇贝和小扇贝血淋巴和肝胰脏中MDA含量相差不大，大扇贝分别为2.67和31.83，小扇贝分别为3.17和35.33。该结果说明，小扇贝对细菌等异物的吞噬和杀灭能力以及机体自身的抗氧化能力高于大扇贝，这为生长与抗逆性相颉抗提供了依据。

95-2重穗型小麦品系生长动态分析

对重穗型小麦品系95－2生长动态分析结果表明，95－2较一般概念上的栽培品系株型粗壮、高大．在整个生育期保持较高的有效光合面积，形成较高的生物学产量，根系发达，形成大穗大粒，体现了源大、库大的特点，茎拜系统也具良好的输导性能。在下一步超高产、稳产品种培育中，植株叶型及其合理配置是一个着重要考虑和解决的问题。

云南墨江金矿床含金石英脉中流体包裹体的地球化学特征及其意义

：本文对含金石英脉中流体包裹体进行了研究，结果表明主阶段石英中流体包裹体均一温度为122～306℃ ,存在两个区间分别为130～22O℃、250～270℃ ，均一温度在水平和垂直方向存在规律性变化，盐度主要集中在3％ ～8％NaCl范围内，密度为0 80～0．95 c ，流体包裹体具有相对稳定的气液比，流体包裹体气液相成分与典型的岩浆水和大气降水不同。结合氢氧锶和稀有气体同位素研究，认为墨江金矿成矿流体曾发生过部分地幔流体、大气降水等多种类型水不充分的混合，水岩反应和多种流体混合可能为墨江金矿矿质迁移沉淀主要机制。结 合哀牢山金矿带成矿流体类似性和流体包裹体特征分析认为墨江金矿深部可能存在有含金石英脉型矿体。

Levantamento de banco de sementes e de flora daninha emergente no manejo integrado de plantas daninhas, em lavouras de soja no Parana - 95/96.

1997