栖热菌属高温菌RH99-02菌株产类胡萝卜素的研究

从腾冲热海分离到最高生长温度达80℃的一株嗜热非芽孢菌RH99-02菌株，经鉴定属Thermus属，对其所产类胡萝卜素进行了吸收光谱扫描及薄层层析分析。发酵研究表明振荡培养时的菌体生物量和色素产量上均高于静置培养，培养至50h菌体生物量和色素产量达到最大值，菌体色素产量为762μg/g干重。

微囊藻毒素LR诱导L-02细胞发生凋亡

目的了解微囊藻毒素(MC)LR对L-02细胞的毒性机制。方法以L-02细胞为材料,用不同浓度的MCLR处理该细胞,观察了细胞增殖能力、细胞形态改变、乳酸脱氢酶(LDH)泄漏、细胞凋亡率及凋亡相关基因等一系列指标的变化。结果 MTT细胞增殖实验可知,MCLR在24 h内对L-02细胞有轻微的抑制作用,随后却促进细胞增殖。48 h处理对 LDH泄漏没有显著影响,延时处理导致LDH泄漏发生,且MCLR浓度越高,LDH泄漏越严重,此结果显示发生了细胞氧化损伤。光镜下50μg/ml的毒素浓度在60 h处理后可造成明

有机磷农药在水生态系中生物净化机理研究——2.CTP-02降解对硝基酚的特性和动力学

从鸭儿湖氧化塘中分离出具有分解对硝基酚能力的细菌Pseudomonas sp.,代号CTP-02。在实验室条件下,细菌培养物降解对硝基酚的速度与时间之间的动力学方程为dc/dt=-K_1t-K_2,细菌降解对硝基酚的最适温度为35℃,最适pH为7.5。CTP-02菌降解对硝基酚过程中首先发生脱硝基作用。

Growth and energy budget of F-2 'all-fish' growth hormone gene transgenic common carp

The growth and energy budget for F-2 'all-fish' growth hormone gene transgenic common carp Cyprinus carpio of two body sizes were investigated at 29.2 degrees C for 21 days. Specific growth rate, feed intake, feed efficiency, digestibility coefficients of dry matter and protein, gross energy intake (I-E), and the proportion of I-E utilized for heat production (H-E) were significantly higher in the transgenics than in the controls. The proportion of I-E directed to waste products [faecal energy (F-E) and excretory energy loss (Z(E) + U-E) where Z(E) is through the gills and U-E through the kidney], and the proportion of metabolizable energy (M-E) for recovered energy (R-E) were significantly lower in the transgenics than in the controls. The average energy budget equation of transgenic fish was as follows: 100 I-E = 19.3 F-E + 6.0 (Z(E) + U-E) + 45.2 H-E + 29.5 R-E or 100 M-E = 60.5 H-E + 39.5 R-E. The average energy budget equation of the controls was: 100 I-E = 25.2 F-E + 7.4 (Z(E) + U-E) + 35.5 H-E + 31.9 R-E or 100 M-E = 52.7 H-E + 47.3 R-E. These findings indicate that the high growth rate of 'all-fish' transgenic common carp relative to their non-transgenic counterparts was due to their increased feed intake, reduced lose of waste productions and improved feed efficiency. The benefit of the increased energy intake by transgenic fish, however, was diminished by their increased metabolism.

Theoretical gain of strained GeSn0.02/Ge1-x-y ' SixSny ' quantum well laser

Using effective-mass Hamiltonian model of semiconductors quantum well structures, we investigate the electronic structures of the Gamma-conduction and L-conduction subbands of GeSn/GeSiSn strained quantum well structure with an arbitrary composition. Our theoretical model suggests that the band structure could be widely modified to be type I, negative-gap or indirect-gap type II quantum well by changing the mole fraction of alpha-Sn and Si in the well and barrier layers, respectively. The optical gain spectrum in the type I quantum well system is calculated, taking into account the electrons leakage from the Gamma-valley to L-valley of the conduction band. We found that by increasing the mole fraction of alpha-Sn in the barrier layer and not in the well layer, an increase in the tensile strain effect can significantly enhance the transition probability, and a decrease in Si composition in the barrier layer, which lowers the band edge of Gamma-conduction subbands, also comes to a larger optical gain.

静压下ZnS（0.02）Te（0.98）混晶的共振喇螺散射研究

于2010-11-23批量导入

In situ annealing treatment and In-doping of GaN epilayers grown by MOVPE

The effects of in situ annealing treatment in the initial growth stage and In-doping during growth of the GaN on the material properties were investigated. GaN was grown by LP-MOVPE. In situ annealing reduced the full-width at half-maximum (FWHM) of X-ray rocking curves and reduced etch pit density of GaN films. It improved the optical properties of the epilayer. Undoped and In-doped GaN films of initial growth stage were investigated. It was found that morphology and optical properties were improved in In-doped samples. (C) 2000 Elsevier Science B.V. All rights reserved.

Initiation and development of water film by seepage

When water seeps upwards through a saturated soil layer, the soil layer may become instability and water films occur and develop. Water film serves as a natural sliding surface because of its very small friction. Accordingly, debris flow may happen. To investigate this phenomenon, a pseudo-three-phase media is presented first. Then discontinuity method is used to analyze the expansion velocity of water film. Finally, perturbation method is used to analyze the case that a water flow is forced to seep upwards through the soil layer while the movement of the skeleton may be neglected relative to that of water. The theoretical evolutions of pore pressure gradient, effective stress, water velocity, the porosity and the eroded fine grains are obtained. It can be seen clearly that with the erosion and re-deposited of fine grains, permeability at some positions in the soil layer becomes smaller and smaller and, the pore pressure gradient becomes bigger and bigger, while the effective stress becomes smaller and smaller. When the effective stress equals zero, e.f. liquefaction, the water film occurs. It is shown also that once a water film occurs, it will be expanded in a speed of (U)(t)/(1 - E >).

甘肃当归新品系DGA2000-02的选育研究

当归新品系DGA2000-02是采用重离子束55MeV/u40Ar+15离子辐照甘肃当归90-01干种子,按新品种选育程序多年选育而成的。2005—2007年,在定西市岷县、渭源县、漳县、陇西县等地当归品系区域试验中,甘肃当归DGA2000-02平均产鲜当归10621.5kg/hm2,较对照品种(甘肃当归90-01)平均增产鲜当归1386.0kg/hm2,增产率15.0%。生育期790d,茎秆深紫色,根系黄白色。测定结果:总灰分4.2%,酸不溶性灰分0.4%,分别优于对照品种16%和33.3%;浸出物61.4%,较规定指标提高4.4%;阿魏酸0.148%,较规定指标提高2.96倍。质量显著优于对照品种和2005年版《中国药典》规定指标。适宜在海拔2000—2600m、年降水量500—600mm的二阴及高寒阴湿生态区栽培。

当归新品系“DGA2000-02”与对照品种的遗传差异分析

当归新品系"DGA2000-02"是利用兰州重离子加速器研究装置(HIRFL)对"岷归1号"进行重离子束辐照选育出来的。与岷归1号相比,DGA2000-02表现出更强的抗病性,产量也有较大提高。对这两个品种的表型、品质及遗传差异进行了系统的分析。为将来进一步选育产量高、品质好及抗逆性强的新品种提供研究基础。

~(12)C离子束的剂量学研究

研究了L-α-丙氨酸剂量计测量12C离子辐射的剂量学特性,实验证明丙氨酸剂量计适用于12C离子辐射的剂量学测量。另外,还研究了12C离子照射人外周血诱发的染色体畸变(双着丝粒+着丝粒环)的剂量效应,在0—8.0 Gy范围内拟合的最佳回归方程为Y=0.858 503D+0.361 5×10-2D2。

双管B_(02)锯齿波发生器的研制

本论文从理论计算到实验结果详细讨论了B02聚束器双管高压锯齿波直接形成装置的研制过程。在3-18MHz的工作频率范围内，锯齿波德峰-峰电压值都达到了期望指标值1100v。而且理论计算结果与实验结果具有非常好的一致性。 前级脉冲放大器的设计与制作在本论文中也有详细讨论。对于实验中用到的各种附属设备在本文中也有所提及。

维生素C生产用菌系2980产酸菌基因转移的筛选模型及转座子Tn5诱变

维生素Ｃ的生产目前国内广泛采用由产酸菌（Ｇｌｕｃｏｎｏｂａｃｔｅｒｏｘｙｄａｎｓ）与伴生菌（Ｂａｃｉｌｕｓｍｅｇａｔｅｒｉｕｍ）组成的２９８０菌系，在２９８０中Ｇ．ｏｘｙｄａｎｓ单独生长传代困难，其生长和产酸需要Ｂ．ｍｅｇａｔｅｒｉｕｍ参与。以ＢａｃｉｌｕｓｓｕｂｔｉｌｉｓＫｉ２１３２（ｐＵＢ１１０）作为伴生菌与原２９８０的Ｇ．ｏｘｙｄａｎｓ组合，获得稳定产酸的新菌系。在此基础上建立了适合我国混菌发酵产酸菌外源基因（Ｋａｎｒ）转移的筛选模型。同时报道了以携带有自杀性载体Ｐ１：：Ｔｎ５的大肠杆菌Ｅ．ｃｏｌｉＷ３１１０为供体菌对Ｇ．ｏｘｙｄａｎｓ进行Ｔｎ５诱变的条件和结果。