R���、C面蓝宝石上生长的InGaN多层量子点的发光性质研究

采用表面钝化和MOCVD低温生长在蓝宝石（0001）面（即C面）和蓝宝石(1(1-bar)02)面（即R���）上形成了InGaN量子点，并构成了该量子点的多层结构。原子力显微镜测试的结果表明单层InGaN量子点平均宽约40nm，高约15nm；而多层量子点上层的量子点则比单层的InGaN量子点大。R���蓝宝石衬底上生长的InGaN量子点和C面蓝宝石衬底上生长的InGaN量子点相比，其PL谱不仅强度高，而且没有多峰结构。这是由于在C面蓝宝石衬底上生长的InGaN/GaN多层量子点沿生长方向[0001]存在较强的内建电场，而在R���蓝宝石衬底上得到的多层量子点沿着生长方向[11(2-bar)0]没有内建电场。InGaN量子点变温光致发光（PL）谱研究发现量子点相关的峰有快速红移现象，这是量子点系统所特有的PL谱特征。用在R���蓝宝石上生长的InGaN量子点作有源层有望避免内建电场的影响，得到高量子效率且发光波长稳定的发光器件。

Fe-57 Mossbauer spectroscopic and magnetic studies of R3Fe29-xVx (R = Y, Ce, Nd, Sm, Gd, Tb, and Dy)

Mossbauer spectra for Fe atoms in the series of R3Fe29-xVx (R = Y, Ce, Nd, Sm, Gd, Tb, and Dy) compounds were collected at 4.2 K. The ratio of 14.5 T/mu(B) between the average hyperfine field B-hf and the average Fe magnetic moment mu(Fe)(MS), obtained from our data, in Y3Fe29-xVx is in agreement with that deduced from the RxTy alloys by Gubbens et al. The average Fe magnetic moments mu(Fe)(MS) in these compounds at 4.2 K, deduced from our Mossbauer spectroscopic studies, are in accord with the results of magnetization measurement. The average hyperfine field of the Fe sites for R3Fe29-xVx at 4.2 K increases with increasing values of the rare earth effective spin (g(J) - 1) J, which indicates that there exists a transferred spin polarization induced by the neighboring rare earth atom.

Mossbauer spectroscopy study of Fe-57 in R3Fe29-xTx (R=Y, Ce, Nd, Sm, Gd, Tb and Dy; T=V and Cr)

Fe-57 Mossbauer spectra for the Fe atoms in the R3Fe29-xTx (R=Y, Ce, Nd, Sm, Gd, Tb, Dy; T=V, Cr) compounds were collected at 4.2 K. The analysis of Mossbauer spectra was based on the results of magnetization and neutron powder diffraction measurements. The average Fe magnetic moments at 4.2 K, deduced from our data, are in accord with magnetization measurements. The average hyperfine field of Tb3Fe29-xCrx (x=1.0, 1.5, 2.0, and 3.0) decreases with increasing Cr concentration, which is also in accordance with the variation of the average Fe magnetic moment in the Tb3Fe29-xCrx compounds.

Crystallographic and magnetic properties of hydride R3Fe29-xTxHy (R=Y, Ce, Nd, Sm, Gd, Tb and Dy; T=V and Cr)

The crystallographic and intrinsic magnetic properties of hydride R3Fe29-xTxHy (R=Y, Ce, Nd, Sm, Gd, Tb, and Dy; T=V and Cr) have been investigated. The lattice constants and the unit cell volume of R3Fe29-xTxHy decrease with increasing R atomic number from Nd to Dy, except for Ce, reflecting the lanthanide contraction. Regular anisotropic expansions, mainly along the a- and b-axis rather than along the c-axis, are observed for all the compounds upon hydrogenation. Hydrogenation leads to an increase in Curie temperature. First-order magnetization processes (FOMP) occur in magnetic fields of around 1.5 T and 4.0 T at 4.2 K for Nd3Fe24.5Cr4.5H5.0 and Tb(3)Fc(27.0)Cr(2.0)H(2.8), and around 1.4 T at room temperature for Gd3Fe28.0Cr1.0H4.2 Abnormal crystallographic and magnetic properties of Ce3Fe29-xTxHy suggest that the Ce ion is non-triply ionized.

大豆根瘤菌种群多样性及结瘤特性研究

环境因子及土著根瘤菌是影响人工接种根瘤菌剂接种效果的两个主要因素。论文分为二部分。第一部分首先考察了外界因素对根瘤菌剂接种效果的影响。应用GUS（葡萄糖苷酶）基因标记技术将标记基因GUS导入受体菌S.fredii 8855，标记菌体形成的根瘤可被GUS染色缓冲液染成兰色，而土著菌形成的根瘤不能着色，由此即可十分简便地确定土著菌的影响程度。盆栽实验表明，S.fredii 8855的结瘤抗酸碱能力高于土著菌，能在土壤中较大范围内迁移。当它的根瘤占有率不小于43％时，接种能显著提高大豆产量。大豆产量与根瘤根瘤占有率呈正相关(r = 0.98)，而与总瘤数关系不大(r = 0.13)。土壤氮素显著抑制其结瘤，补加磷能缓解这种抑制作用。研究发现应用快生型大豆根瘤菌剂为保证接种效果，接种量至少应为土著根瘤菌数量的10~5倍，同时施用磷肥会提高接种效果。只有当接种根瘤菌的占瘤率在40％以上时接种才可能达到增产目的。第二部分较为系统地考察了新疆主要大豆产区耕作土中大豆根瘤菌种群数量、种群结构及种群共生、遗传多样性。新疆大豆地耕作土中含有数量较高的大豆根瘤菌，数量每克土大多在10~5-10~6之间，种群结构大多以快生型根瘤菌为主。对分离的28株根瘤共生及遗传多样性进行了分析，土著大豆根瘤菌菌株间结瘤能力有一定差异，快生型大豆根瘤菌总体结瘤能力高于慢生型，但差异不显著(p <= 0.05)，形成的根瘤大小也有较大差异。根瘤菌种群中菌株间为植物提供的生物固氮量存在明显差别，但仅有20％的菌株能明显促进植物生长，有1/3的菌株具有较高的固氮能力。慢生型大豆根瘤菌固氮能力明显高于快生型，但二者之间差异未达到显著水平(p < 0.05)。根瘤菌结瘤力与固氮活性之间的相关性分析发现许多根瘤菌形成的根瘤为无效根瘤。重复序列（重复基因外回文REP和肠细菌重复基因间共同序列ERIC）结合聚合酶链式反应(ERP和ERIC－PCR)用于大豆根瘤菌染色体指纹分析，分析结果表明新疆土著大豆根瘤菌具有复杂的遗传多样性，遗传相近程度具有一定的地域性，来自同一地区的根瘤菌株具有较高的遗传相似性。新疆土著大豆根瘤菌在相似水平0.5可分为两大类群，一个类群包括所有慢生型根瘤菌，另一类群为所有快生型根瘤菌。在相似水平0.6大豆根瘤菌可分为5个聚群，快生型根瘤菌分为二个主要聚群和一个次要类群，慢生型根瘤菌分为二个次要类群。主要聚群中一个聚群结瘤能力较高但固氮能力较低，另一聚群结瘤能力和固氮量均较低；次要聚群中快生型和一个慢生型聚群固氮能力较高但结瘤力低，另一慢生型聚群固氮能力和结瘤力均较高。以上研究表明，新疆绿洲农业生态系统中大豆根瘤菌具有一定种质特异性，尽管次要类群具有相对较高的因氮活性，但由于多数根瘤菌形成的根瘤为固氮活性很低的无效根瘤，占优势的主要聚群固氮活性较低，因此土著根瘤菌生物固氮量不能满足作物对氮素的需求，在新疆人工施用根瘤菌剂具有现实意义，但接种的根瘤菌剂可能受到对环境适应性强、结瘤能力高的土著根瘤菌优势类群强有力的竞争。

CFD analysis of pneumatic conveying in a double-tube-socket (DTS (R)) pipe

A pipeline with a bypass is widely used for the pneumatic conveying of material. The double-tube-socket (DTS (R)) technology, which uses a special inner bypass, represents the current state of the art. Here, a new methodology is proposed based on the use of computational fluid dynamics (CFD) to predict the energy consumption of DTS conveying. The predicted results are in good agreement with those from pilot-scale experiments. (C) 2010 Elsevier Inc. All rights reserved.

NEW METHODOLOGY FOR THE ESTIMATION OF ENERGY CONSUMPTION IN A DOUBLE-TUBE-SOCKET (DTS (R)) PNEUMATIC CONVEYING

A new methodology based on the use of CFD is proposed to estimate the energy consumptions in a DTS (DOUBLE-TUBE-SOCKET) pneumatic conveying. A simple computational program based on this methodology is developed. It can directly give the lowest energy consumption and the compatible gas consumption by only input the distance of conveying and the conveying tonnage. This computational program has been validated through our experimental work.

R IBLL终端LA SCAR���列探测器PM T高压控制系统的研制

介绍了R IBLL终端LA SCAR���PM T阵列电源高压控制系统。该系统以当今工程控制中常用的微型计算机作为核心器件,采用合适的外围电路达到了对PM T阵列稳定、可靠的控制,在现场测试中取得了良好的效果。

高离化态S~(q+)与H_2碰撞中H_2~(r+)的库仑爆炸及解离过程研究

采用位置灵敏探测器和散射离子 反冲离子飞行时间技术测量了 90 0keV的Sq + +H2 碰撞产生的H+ 碎片的能量分布 ,实验表明部分Hr+ 2 发生解离。基于蒙特卡罗方法 ,建立了程序模拟离子与分子碰撞中的反冲离子飞行时间谱。模拟结果与实验 (S2 + +H2 ,S2 + +He)测量到的TOF谱进行了分析比较 ,并进行了定性讨论。

General SU(2)(L) x SU(2)(R) x U(1)(EM) sigma model with external sources, dynamical breaking and spontaneous vacuum symmetry breaking

We give a general SU(2)(L) x SU(2)(R) x U(1)(EM) sigma model with external sources, dynamical breaking and spontaneous vacuum symmetry breaking, and present the general formulation of the model. It is found that sigma and pi(0) without electric charges have electromagnetic interaction effects coming front the internal structures. A general Lorentz transformation relative to external sources J(gauge) - (J(A mu) J(A mu)(kappa)) derived, using the general Lorentz transformation and the four-dimensional current of nuclear matter of the ground si ate with J(gauge) = 0, we give the four-dimensional general relations between the different currents of nuclear matter systems with J(gauge) not equal 0 and those with J(gauge) = 0. The relation of the density's coupling with external magnetic field is derived, which conforms well to dense nuclear matter in a strong magnetic field. We show different condensed effects in strong interaction about fermions and antifermions, and give the concrete scalar and pseudoscalar condensed expressions of sigma(0) and pi(0) bosons. About different dynamical breaking and spontaneous vacuum symmetry breaking, the concrete expressions of different mass spectra are obtained in field theory. This paper acquires the running spontaneous vacuum breaking value sigma'(0), and obtains the spontaneous vacuum breaking in tenus of the running sigma'(0), which make nucleon, sigma, and pi particles gain effective masses. We achieve both the effect of external sources and nonvanishing value of the condensed scalar and pseudoscalar paticles. It is deduced that the masses of nucleons, sigma and pi generally depend on different external sources.

Ginsenoside R-e increases fertile and asthenozoospermic infertile human sperm motility by induction of nitric oxide synthase

We investigated the effects of Ginsenoside R-e on human sperm motility in fertile and asthenozoospermic infertile individuals in vitro and the mechanism by which the Ginsenosides play their roles. The semen samples were obtained from 10 fertile volunteers and 10 asthenozoospermic infertile patients. Spermatozoa were separated by Percoll and incubated with 0, 1, 10 or 100 mu M of Ginsenoside R-e. Total sperm motility and progressive motility were measured by computer-aided sperm analyzer (CASA). Nitric oxide synthase (NOS) activity was determined by the H-3-arginine to H-3-citrulline conversion assay, and the NOS protein was examined by the Western blot analysis. The production of sperm nitric oxide (NO) was detected using the Griess reaction. The results showed that Ginsenoside R-e significantly enhanced both fertile and infertile sperm motility, NOS activity and NO production in a concentration-dependent manner. Sodium nitroprusside (SNP, 100 nM), a NO donor, mimicked the effects of Ginsenoside R-e. And pretreatment with a NOS inhibitor N-omega-Nitro-L-arginine methyl ester (L-NAME, 100 mu M) or a NO scavenger N-Acetyl-L-cysteine (LNAC, 1 mM) completely blocked the effects of Ginsenoside R-e. Data suggested that Ginsenoside R-e is beneficial to sperm motility, and that induction of NOS to increase NO production may be involved in this benefit.

以转座子Tn5作弗氏中华根瘤菌的可识别生态学标记的研究──Tn5的水平转移及其对R���frediiTn5突变株运动的影响

将一株弗氏中华根瘤菌（Ｒ．ｆｒｅｄｉｉ）ＱＢ１１３０的Ｔｎ５插入突变株ＯＮ－２用于生态学研究，以评估Ｔｎ５在自然环境中的水平转移以及各种水势下Ｔｎ５对突变株ＯＮ－２在土壤中运动的影响．试验表明，在自然潮湿的土壤中，Ｔｎ５本身的水平转移频率很低，且与Ｔｎ５插入相关的突变株卡那霉素抗性表型标记在非选择性平板上连续传４０代后仍然稳定．突变株ＯＮ－２与相对应的野生型菌株ＱＢ１１３０在各种相同水势的土壤中的运动无明显差异（Ｐ＝０．０１），表明Ｔｎ５的插入不影响突变株的运动．因此，Ｔｎ５可作为研究Ｒ．ｆｒｅｄｉｉ基因工程菌大回应用的一个稳定有效的生态学标记．