暗纹东方鲀年龄鉴定的研究

用耳石、脊椎骨、鳃盖骨等识别和鉴定暗纹东方鲀(Takifugu obscurusAbe)的年龄,在描述其轮纹特征基础上,比较其在判读暗纹东方鲀年龄和生长特征上的异同与准确性。结果表明,耳石磨片上的轮纹特征明显、清晰且规律性强,是最好的年龄鉴定材料;脊椎骨轮纹也很清晰,但测量时有一定难度,也是较好的年龄鉴定材料;鳃盖骨上年轮较难判定,只能作为辅助材料。本文还对牙齿能否作为年龄鉴定材料进行了观测。

中国典型地带29种土壤纤毛虫记述(纤毛门:动基片纲)

记述了在中国６个典型地带土壤中鉴定到的隶属于动基片纲的２９种纤毛虫，其中５种为中国土壤原生动物新记录种．这些种类是：陆生拟裸口虫，恼斜板虫，吻瓶口虫，双核管形虫，琴刀口虫，长刀口虫，长尾刀口虫，斜叶苔叶虫，神螺流苏虫，土壤肾形虫，三分肾形虫，背沟肾形虫，无规肾形虫，直立肾形虫，粗糙拟肾形虫，莫氏拟肾形虫，贪食阔庭虫，大撕拉虫，吻吴氏虫，澳洲吴氏虫，大口匙口虫，尖锐密粒虫，卡氏颠毛虫，小拟匙口虫，尖锐篮环虫，丛林拟篮环虫，有肋薄咽虫，弧形微秀体虫和凤冠齿扇虫．

Crustacean zooplankton distribution patterns and their biomass as related to trophic indicators of 29 shallow subtropical lakes

A comparative limnological study was carried out to present a snapshot of crustacean zooplankton communities and their relations to environmental factors to test whether there is a consistent relationship between crustacean biomass and trophic indicators among lake groups with similar trophic conditions. The study lakes showed a wide range of trophic status, with total phosphorus (TP) ranging from 0.008 to 1.448mgL(-1), and chlorophyll a from 0.7 to 146.1 mu g L-1, respectively. About 38 species of Crustacea were found, of which Cladocera were represented by 25 taxa (20 genera), and Copepoda by 13 taxa (I I genera). The most common and dominant species were Bosmina coregoni, Moina micrura, Diaphanosoma brachyurum, Cyclops vicinus, Thermocyclops taihokuensis, Mesocyclops notius and Sinocalanus dorrii. Daphnia was rare in abundance. Canonical correspondence analysis showed that except for four species (D. hyalina, S. dorrii, C. vicinus and M. micrura), almost all the dominant species had the same preference for environmental factors. Temperature, predatory cyclopoids and planktivorous fishes seem to be the key factors determining species distribution. TP was a relatively better trophic indicator than chlorophyll a to predict crustacean biomass. Within the three groups of lakes, however, there was no consistent relationship between crustacean biomass and trophic indicators. The possible reason might be that top-down and bottom-up control on crustaceans vary with lake trophic state. The lack of significant negative correlation between crustacean biomass and chlorophyll a suggests that there was little control of phytoplankton biomass by macrozooplankton in these shallow subtropical lakes. (c) 2007 Elsevier GmbH. All rights reserved.

Metamorphic growth of 1.25-1.29 mu m InGaAs quantum well lasers on GaAs by molecular beam epitaxy

We demonstrate 1.25-1.29 mu m metamorphic laser diodes grown on GaAs by molecular beam epitaxy (MBE) using an alloy-graded buffer layer (GBL). Use of Be in the GBL is effective to reduce surface/interface roughness and improves optical quality. The RMS surface roughness of the optimized metamorphic laser is only two atomic monolayers for 1 x 1 mu m(2). Cross-sectional transmission electron microscopy (TEM) images confirm that most dislocations are blocked in the GBL. Ridge waveguide lasers with 4 mu m wide ridge were fabricated and characterized. The average threshold current under the pulsed excitation is in 170-200 mA for a cavity length of 0.9-1.5 mm. This value can be further reduced to about 100 mA by high-reflectivity coating. Lasers can work in an ambient temperature up to at least 50 degrees C. (c) 2006 Elsevier B.V. All rights reserved.

Growth mechanism of InGaAlAs waveguides by narrow stripe selective MOVPE

Growth mechanism of InGaAlAs waveguides by narrow stripe selective MOVPE has been studied. Both the InGaAlAs bulk waveguides and the InGaAlAs MQW waveguides were successful grown on the patterned substrates at optimized growth conditions. The mask stripe width varied from 0 to 40 mu m, while the window region width between a pair of mask stripes was fixed 2.5 mu m. These selectively grown waveguides were covered by specific InP layers, which can keep the InGaAlAs waveguides from being oxidized during the fabrication of devices. In particular, there exhibit strong dependences of the photoluminescence (PL) spectrum on the mask stripe width for the samples. The results were explained in considering both the migration effect from a masked region (MMR) and the lateral vapor diffusion effect (LVD).

BF＋对（29）Si＋注入GaAs层的影响

于2010-11-23批量导入

柞蚕林生态系统生物生产力与养分循环模式研究

本文研究了辽东山区不同经营强度下柞蚕林生态系统物质转运和养分循环。在同一个轮伐期内，柞蚕林叶生物量、年净生产量随剪伐年令的增加而增大，直到剪伐后5年呈下降趋势。植被总生物量介于22.23-24.56t·ha~(-1)。其中乔木层、灌木层、草本层各为17.84、2.82、3.17t·ha~(-1)。林地枯枝落叶层总量为3.56-4.37t·ha~(-1)。年净生产量介于8.51-8.92t·ha~(-1)·yr~(-1)。其中乔木层占53.7%、灌木层占16.3%、草本层占29.9%。当食叶强度为0、50%和75%时，年干物质归还总量分别为3.57-3.96、3.38-3.725和3.284-3.609t·ha~(-1)·yr~(-1)。干物质净输出各为0、93.34-117.59和140.02-176.36kg·ha~(-1)·yr~(-1)。干物质积累和分配的分隔模型阐明了系统中干物质现存量和流动量。柞蚕林植被养分积累总量为255.69-292.15kg·ha~(-1)。在乔木层中，叶 > 根桩、树干 > 侧根、多年生枝 > 当年枝、细根。柞叶在衰老过程中，养分浓度急剧下降（40.62-77.78%）。在不同食叶强度下，分别计算了营养元素的回运量、归还量、输出量和存留量、植被养分年吸收总量以及调整前后乔木层各器官的年净吸收量。养分循环的分隔模型阐明了不同经营条件下柞林-柞蚕系统养分的分配和流动特征。

花椒水浸液及酚酸类化感物质对作物种子萌发和幼苗生长的影响效应

花椒（Zanthoxylum piperitum）是川西干旱河谷地区的重要经济作物，化感作用是花椒连作障碍的原因之一。系统研究花椒化感作用有助于深入理解并最终解决花椒连作障碍。本文通过研究花椒叶、林下土壤浸提液及单一纯化感物质对花椒幼苗生长、苜蓿种子萌发及幼苗生长的影响作用，从生理生化角度揭示浸提液及纯化感物质的作用方式。通过室外和室内模拟实验，对浸提液及纯化感物质的化感效应进行比较，为花椒连作障碍的解决和化感作用机制的深入理解提供依据。主要结果如下： 1.花椒叶及林下土壤浸提液对地下生物量影响作用强与对地上生物量的化感效应，两种浸提液的化感效应强度不同，叶浸提液作用表现更显著。其中在Y6、Y8 、T6和T8处理时，花椒幼苗地下生物量分别降低了31.2%、32.1%、31.6%和31.7%。 2.两种浸提液均能显著影响花椒幼苗体内的保护性酶活性，总体说来，在高浓度下抑制各种抗氧化物酶活性，幼苗体内丙二醛含量增加，幼苗受害严重；在较低浓度下，各种保护性酶活性有所增加，丙二醛含量减少，幼苗伤害减轻。同时，不同月份里，各种酶的活性高低显著不同，9月份的活性显著低于7月份的酶活性。对于养分含量的影响，Y8、T8的影响强度最大，分别使碳元素含量降低了27.8%和30.8%，使钾元素含量降低了34.7%和25.6%。 3.花椒叶及林下土壤浸提液对苜蓿种子萌发及幼苗生长有化感作用，表现在最终萌发率、不同物质代谢及保护性酶活性的差异上。两种浸提液对苜蓿种子萌发过程中蛋白质的含量均无显著性影响，对淀粉和可溶性糖的影响作用类似，高浓度处理无明显化感效应，较低浓度处理显著降低二者在萌发苜蓿种子中的含量。Y2、Y4与T4处理分别使可溶性糖含量减少了32.3%、29.1%和18.8%，Y2与T2处理分别使淀粉含量降低了29.3%和26.8%。 4.苜蓿种子在4种单一化感物质最高浓度即10-3 mol•L-1处理下，萌发率显著降低，半数萌发时间推迟，随着处理浓度降低，抑制作用逐渐减弱，当降低到10-6 mol•L-1时，又能够表现出对苜蓿种子萌发的促进作用。 5.纯化感物质在10-6 mol•L-1时使苜蓿幼苗叶片的保护性酶活性显著升高，丙二醛含量显著降低；在10-3 mol•L-1时使苜蓿叶片中保护性酶活性显著降低，丙二醛含量增加，膜脂过氧化程度加重。 Zanthoxylum piperitum is one of the most important cash crops and has been extensively cultivated in Eastern Tibetan Plateau, especially in the fragile dry valley areas. Allelopathic effects could be a reason for Z. piperitum’s continuous cropping impediment. Systemmatically research of the effect of Z. piperitum allelopathy could help to comprehend the continuous cropping impediment. The allelopathic effects on seedlings growth and seed germination of aqueous extracts of Zanthoxylum piperitum and phenolic allelochemicals were studied, and the action mechanism of the two substances was also discussed from physiology. Indoor and outdoor experiments were set to compare the difference between aqueous extracts and pure allelochemicals. The main results showed that: 1. The aqueous extracts of leaf and soil had significant allelopathic effects on aboveground and underground biomass, but the effect on underground biomass was stronger than the effect on underground evidently. Treated with Y6、Y8 、T6 and T8, the underground biomass was reduced 31.2%、32.1%、31.6% and 31.7% respectively. 2. The activity of activities of superoxide dismutase, catalase, peroxidase and ascorbate peroxidase were significantly reduced, while the content of MDA was increased and the seedlings were suffered stronger, when treated by the high concentration; but at the low concentration, these were reversed. And then, at the different month, the activities of antioxidant enzyme were significantly distinct. As for the contents of nutrient element, Y8、T8 had the more intensive effects than other treatments. 3. The results showed that the two types of aqueous extracts had significant allelopathic effects on seed germination, substances metabolize and the activity of antioxidant enzyme. But the aqueous extracts had no effects on the content of protein, while had the similar effects on the content of starch and soluble sugar. At Y2、Y4 and T4, the content of soluble sugar decreased 32.3%、29.1% and 18.8% respectively. 4. Treated with 10-3 mol•L-1 of the four allelochemicals, the seed germination of alfalfa was significantly inhibited. Ferulic acid, coumarin and vanillic acid at 10-3 mol•L-1 significantly reduced the activities of antioxidant enzyme, while the content of MDA in alfalfa seedling was significantly increased. The restrain effects became weakened with the treat concentration falled. However, ferulic acid, coumarin and vanillic acid could increase the activities of antioxidant enzyme at 10-6mol•L-1.

~(29)S双质子的同时发射

<正>近年来,双质子发射的现象被广泛研究。~(29)S核最外层两个质子处于2s1/2轨道,可能存在这种奇特的行为。先前的实验表明,~(29)S+~(28)Si的总反应截面有着异常大的值。这意味着~(29)S中最后2

Experimental study of two-proton correlated emission from S-29 excited states

An experiment of a S-29 beam bombarding a Au-197 target at an energy of 49.2 MeV/u has been performed to study the two-proton correlated emission from S-29 excited states. Complete-kinematics measurements were carried out in the experiment. The relative momentum, opening angle, and relative energy of two protons, as well as the invariant mass of the final system, were deduced by relativistic-kinematics reconstruction. The Si-27-p-p coincident events were picked out under strict conditions and the phenomenon of p-p correlations was observed among these events. The mechanisms of two-proton emission were analyzed in a simple schematic model, in which the extreme decay modes like He-2 cluster emission, three-body phase-space decay, and two-body sequential emission were taken into account. Associated with the Monte Carlo simulations, the present results show that two protons emitted from the excited states between 9.6 MeV and 10.4 MeV exhibit the features of He-2 cluster decay with a branching ratio of 29(-11)(+10)%.

Kinetic energy and charge state effects in the X-ray emission of Mo surface induced by Xeq+ (q=25, 29) ions

L-shell X-ray spectra of Mo surface induced by Xe25+ and Xe29+ were measured. The X-ray intensity was obtained in the kinetic energy range of the incident ions from 350 to 600 keV. The relationship of X-ray intensity with kinetic energy of the projectile and its charge state were studied, and the simple explanation was given.

Experimental study of the two-proton correlated emission from the excited states of Ne-17,Ne-18 and S-28,S-29

A series of experiments have been performed by complete kinematics measurements to study two-proton (2p) correlated emission from the excited states of Ne-17,Ne-18 and S-28,S-29 via the Coulomb excitation by bombarding on Au-197 target. 2p and residua coincident events were picked Out under strict conditions. Visible p-p correlations were observed. It is shown that 2p can be emitted from the high-lying excited states. 2p halo may lead to 2p emission with large spectroscopy factor for the states close to or beyond the threshold.