多停止信号分拣器

本实用新型主要涉及信号分拣器。一种多停止信号分拣器，包括有信号分拣器输入端口，外部逻辑控制输入端口，其主要特点是输入端与多路分除电路相连；信号成形电路连于多路分除电路及信号电平转换电路之间；信号电平转换电路与提供多路时间幅度转换器（ＴＡＣ）和时间数字转换器（ＴＤＣ）所需要的快ＮＩＭ信号输出端口相连。本实用新型提供了一种通用的标准快电子学设计，能够使得普通ＮＩＭ标准多路时间幅度转换器（ＴＡＣ）经过ｎ路组合，或者采用ＣＡＭＡＣ标准的多路时间数字转换器（ＴＤＣ）插件，实现多停止时间数字转换器（ＴＤＣ）的功能，完成任意多个停止时间信号的探测。它的造价比ＣＡＭＡＣ多停止时间数字转换器（ＴＤＣ），尤其是比ＶＭＥ多停止时间数字转换器（ＴＤＣ）要低得多。无需对用户现有的ＴＡＣ或者ＴＤＣ作改造，适用于各种数据采集系统，提高现有仪器的利用效率，节约用户研究费用。

极高精度基准电压源

本实用新型公开一种极高精度基准电压源。供电电路采用串联调整电路、交流２２０Ｖ电压经整流滤波后，再经二级三端稳压器预稳压，将电压稳定在±１５Ｖ，再经调整放大管放大给末级ＬＭ３９９供电，给运算放大器ＯＰＡ２２２７提供基准电压。基准电压与取样电路构成差模电压，经运算放大器放大后去推动复合调整管工作，给ＬＭ３９９提供稳定电流。取末级ＬＭ３９９的Ｒ↓［ｆ］＝９ＫΩ、Ｒ↓［Ｌ］＝２０ＫΩ，最终获得１０Ｖ基准电压源。本实用新型在重离子加速器中得到了应用，实际工作中性能稳定，工作可靠。成功地完成了兰州重离子加速器电源改造项目。

表面活化氢氧化镁阻燃剂的制备工艺

本发明涉及一种表面活化氢氧化镁阻燃剂的制备工艺，该工艺含有下述步骤：①取氢氧化钠与水制成氢氧化钠稀溶液；②取硬脂酸并加入水混合加热溶解后，将其加入氢氧化钠稀溶液中生成硬脂酸钠；③在硬脂酸钠中加入磺化蓖麻油，调节其ｐＨ值为６－８，再加入水，恒温下搅拌至生成白色脂肪酸皂胶乳；④取氢氧化镁粉料，在其内全部加入③步制备的脂肪酸皂胶乳，再在恒温下搅拌至成品中含脂量为０．３－０．７％时，将浆状物取出；⑤将取出的浆状物在低于１１０℃下干燥并粉碎即可；本发明利用合成的阴离子表面活性剂胶乳对氢氧化镁阻燃剂进行表面处理，以便改善其在聚合物中的相容性和加工性能，并具有成本低廉、使用安全等特点。

Genetic heterogeneity analysis and RAPD marker detection among four forms of Atrina pectinata Linnaeus

Pen shell (Atrina pectinata Linnaeus) can be distinguished into four forms based on the morphololgic characteristics. Genetic similarity, and heterogeneity were analyzed among the four forms by random amplified polymorphic DNA (RAPD) technique using 24 10-nucleotide-long primers. Of these primers, 22 pruners produced well-identifiable RAPD band patterns. Significant differences in RAPD band patterns were revealed among the four forms. A total of 198 polymorphic fragments were scored from 22 pruners. and they are specific for one form, shared by two or three forms. Several pruners, such as S451, S453 S463 S464, S470. S473 and S474, produced abundant band patterns and provided sufficient information for reliable discrimination of the four forms. The average genetic distances and phylogenetic relationships were calculated and analyzed according to the distinguishable fragments. The data indicate that pen shells of form G and form Y are similar not only among individuals within the same form, but also between individuals from the two forms, and that shells of form T and form S are highly divergent. The constructed phylogenetic free matches the average genetic distances. Three clusters were clearly distinguishable, in which two were corresponding to form S and form T respectively and one included forms G and Y. This Study will be benefit to further studies oil the taxonomy and selective breeding of Pinnid species. It is suggested that the four forms of pen shell should be categorized to at least two species taxonomically.

Distribution of the meiofaunal community in a eutrophic shallow lake of China

In a Chinese eutrophic shallow lake, the spatial, temporal and vertical distributions of meiofauna in different lake zones along a eutrophic gradient were analyzed. The spatial distribution of meiofauna among sampling stations changed with nutrient levels. Nematoda were most abundant at the majority of sampling stations comprising 70.6 - 93.2 % meiofaunal abundance except for a hypereutrophic station. The seasonal patterns in abundance of nematodes, oligochaetes, rotifers, chironomids and different nematode feeding groups differed among stations, which revealed that the temporal variations of these meiofaunal groups and the nematode feeding groups may vary with different nutrient loadings. The vertical distributions of meiofaunal groups, nematode species, and nematode trophic groups in the upper and lower sediment layers were similar, suggesting a consistent vertical distribution pattern across different trophic conditions. Nematode species richness, Shannon-Wiener species diversity index, trophic diversity and Maturity Index were significantly correlated with nutrient levels (total phosphorus and nitrogen in lake water and total phosphorus in sediment). Our results suggest the importance of nematode community analyses in the assessment of freshwater eutrophication.

Research progress on algae of the microbial crusts in and and semiarid regions

Microbial crusts are attracting much interest in view of their possible uses in environmental conservation and ecological restoration of the and and semiarid regions. Because algae play an irreplaceable important role in the early formation and the strengthening of microbial crusts, they are paid much more attention to than other cryptogams. In this paper, an overview of the current knowledge on the fine structure and development of microbial crust, focusing on the algal biomass, vertical distribution, succession, influential factors on algae, cohesion of soil stabilization, cementing mechanism for soil particles and the microalgal extracellular polymers is given, with particular emphasis on the authors' researches, and some prospects are put forward as well.

Cloning of rainbow trout (Oncorhynchus mykiss) histone H3 promoter and the activity analysis in rare minnow (Gobiocypris rarus)

Rainbow trout historic H3 (RH3) promoter was cloned via high fidelity PCR. The cloned RH3 promoter was inserted into a promoter-lacked vector pEGFP-1, resulting in an expression vector pRH3FGFP-1. The linearized pRH3EGFP-1 was microinjected into fertilized eggs of rare minnows and the sequential embryogenetic processes were monitored under a fluorescent microscope. Strong green fluorescence was ubiquitously observed at as early as the gastrula stage and then in various tissues at the fry stage. The results indicate that RH3 promoter, as a piscine promoter, could serve in producing transgenic Cyprinoid such as rare minnow. Promoter activity of RH3, CMV and common carp beta-actin (CA) were compared in rare minnow by the expression of respective recombinant EGFP vectors. The expression of pCMVEGFP occurred earlier than the following one, pRH3EGFP-1, and then pCAEGFP during the embryogenesis of the transgenics. Their expression activities demonstrated that the CMV promoter is the strongest one, followed by the CA and then the RH3.

Molecular phylogenetic relationships of Eastern Asian Cyprinidae (Pisces : Cypriniformes) inferred from cytochrome b sequences

Complete mitochondrial cytochrome b sequences of 54 species, including 18 newly sequenced, were analyzed to infer the phylogenetic relationships within the family Cyprinidae in East Asia. Phylogenetic trees were generated using various tree-building methods, including Neighbor-joining (NJ), Maximum Parsimony (MP) and Maximum Likelihood (ML) methods, with Myxocyprinus asiaticus (family Catostomidae) as the designated outgroup. The results from NJ and ML methods were mostly similar, supporting some existing subfamilies within Cyprinidae as monophyletic, such as Cultrinae, Xenocyprinae and Gobioninae (including Gobiobotinae). However, genera within the subfamily "Danioninae" did not form a monophyletic group. The subfamily Leuciscinae was divided into two unrelated groups: the "Leuciscinae" in East Asia forming as a monophyletic group together with Cultrinae and Xenocyprinae, while the Leuciscinae in Europe, Siberia, and North America as another monophyletic group. The monophyly of subfamily Cyprininae sensu Howes was supported by NJ and ML trees and is basal in the tree. The position of Acheilognathinae, a widely accepted monophyletic group represented by Rhodeus sericeus, was not resolved.

Effect of a feeding stimulant on feeding adaptation of gibel carp Carassius auratus gibelio (Bloch), fed diets with replacement of fish meal by meat and bone meal

The objectives of the study were to investigate the effect of a feeding stimulant on feeding adaptation of gibel carp (Carassius auratus gibelio Bloch) fed diets with replacement of fish meal by meat and bone meal (MBM), and whether or not the juvenile gibel carp could adapt to higher MBM level in the diet. Juvenile and adult gibel carp were tested. Two and one replacement levels were used for juvenile and adult fish respectively. Each group of diets was set as two types with or without a unique rare earth oxide: Y2O3, Yb2O3, La2O3, Sm2O3, Nd2O3 or Gd2O3 (only the first four rare earth oxides were used in adult diets) for four adaptation periods of 3, 7, 14 and 28 days respectively. After mixing, an equal mixture of all six diets for juvenile or four diets for adult was offered in excess for 2 days. During the last 2 days of each experiment, no feed was offered and faeces from each tank were collected. Feeding preference was expressed as relative feed intake of each diet, which was estimated based on the relative concentration of each marker in the faeces. Given some adaptation period, such as 3-28 days, the effects of MBM and squid extract inclusion on the preference to each diet were reduced. After 28 days adaptation, the preferences between groups were not significantly different.

Artificial interspecific hybridization between Macrobrachium species

Viable F-1 hybrids were obtained from crosses of female Macrobrachium nipponense and male Macrobrachium hainanense involving spermatophore transfer and artificial insemination. This represents the first successful known case of hybridization of two Macrobrachium species by means of artificial insemination. The hatching rate was over 90%. About 20-60% of newly hatched larvae metamorphosed to postlarvae. The morphological characteristics of the hybrids resembled a combination of features of both parents. Malate dehydrogenase (MDH) and esterase (EST) isozyme electrophoresis indicated parents and F-1 hybrids showed co-dominant expression of the paternal and maternal alleles controlling the isozymes and confirmed the hybridization. (C) 2004 Elsevier B.V. All rights reserved.

波长可调谐分布布拉格反射激光器的制作方法

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非划分的仿生模式识别方法

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氮化镓及其化合物半导体的横向外延生长方法

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