60 resultados para 795
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本文论述用于兰州重离子加速器冷却存储环(HIRFL-CSR)控制系统的前端总线系统控制器FBC-01的硬件设计。该控制器是基于0.8mmBGA封装的AT91RM9200(ARM9)处理器,运行嵌入式LINUX操作系统。控制器可以连接标准的VGA显示器、键盘、鼠标,具有通用的10M/100M以太网接口、USB接口、RS-232接口、485接口、CANBUS接口。可以带SD卡、CF卡存储器。该控制器采用现场可编程的FPGA器件设计背板接口,并采用具有64mA高驱动能力的总线驱动器,不仅符合VME规范的电气要求,而且具有灵活的接口信号定义可编程能力,是HIRFL-CSR控制系统的关键部件。
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<正>质量数80区的过渡性核表现了集体性和单粒子性的能级结构。对质子数Z为37~40、中子数N=45的原子核,如81Kr,87Mo核,在中低自旋时显示了单粒子特性,而在高自旋态时表现出较多的集体性。 近些年来,在过渡区在束γ谱学,如83Rb、83Y等核研究中,观察到了一串建立在较高K态的增强的△I=1的M1跃迁。它被认为是一种新的激发模式,叫做磁转动带。我们对85Zr的研究目的,一是将其能级推到更高自旋,另一个是寻找该核的磁转动带。
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采用微生物菌落计数方法和Pearson相关性分析,以辽河油田锦采污水处理厂稠油废水为对象,研究了不同季节稠油废水中优势微生物的种群组成及其变化规律。结果表明,在稠油废水处理过程中微生物种群组成及其作用均以细菌为主,真菌次之,放线菌最小;细菌菌落形态多样性指数(H′)与均匀度指数(E)均能较准确地反映废水中的细菌多样性,但不能反映水质状况,不宜作为该水质评价的生物指标;细菌数量与总石油烃(TPH)和COD均呈强正相关,统计学上关系显著,适宜作为废水水质评价的生物指标;经鉴定,废水中的优势菌株为液化金杆菌(Aureobateriumliquefaciens)和弗氏丙酸杆菌(Propionibacterium freudenreichii),主要真菌为青霉属(Penicillium)、曲霉属(Aspergillus)、木霉属(Trichoderma)和交链孢霉属(Alternaria)。
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The reaction of producing hydrogen for fuel cell which used normal octane as gasoline or diesel oil reactant through catalytic partial oxidizing and steam reforming method has been researched in the fixed-bed reactor. A series of catalysts that mainly used nickel supported on Al2O3 have been studied. It showed that the activity of the catalyst was increased with the content of nickel by using only nickel supported on Al2O3. However, its activity was not obviously increased when the content of nickel was over 5 wt%. The conversion ratio of normal octane and hydrogen selectivity were higher at higher reaction temperature. The single noble catalyst of palladium had better stability compared with that of platinum catalyst although their activity and selectivity were similar during the experimental reaction temperature. The prepared bimetallic catalyst consisted mainly of nickel and little noble metal of palladium supported on Al2O3. It showed that this catalyst had higher activity and selectivity, especially at lower or higher reaction temperatures compared with single nickel or palladium catalyst, and better stability. ((C) 2001 International Association for Hydrogen Energy. Published by Elsevier Science Ltd. All rights reserved.
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为揭示本氏针茅(Stipa bungeana Trin.)群落的生理生态适应机制,采用根系取样器(Φ=9 cm)对宁夏云雾山本氏针茅群落根系分布特征和土壤含水量进行研究。结果表明:本氏针茅群落地下生物量、根长密度、根表面积、比根长均随土壤深度增加而减少,均表现出向表层(0~20 cm)集聚的趋势,且集中分布于0~40 cm土层,最大值均分布在0~20 cm土层,而底层(80~100 cm)最小;所有主要根系分布参数在0~20 cm和20~40 cm土层之间差异显著,以下各层差异不显著;土壤含水量与根生物量和比根长相关性达显著水平(P<0.05),与根表面积、根长密度均呈成正相关;根表面积、根生物量、根长密度和比根长间相关性均达极显著水平(P<0.01)。
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宁康霉素(Nincomycin)产生菌BAC-9912经紫外线单因子和亚硝基胍化学试剂诱变后,获得两株高产菌株9912-7-2U(UV处理获得)和9912-2U-32N(NTG处理获得),其摇瓶效价分别为176.464×105u·L-1和217.808×105u·L-1。比出发菌株效价分别提高126.9%和180.0%。连续传代摇瓶效价稳定。初步建立了形态观察法和琼脂块大通量法两种初筛模型。
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土壤铁元素由高价态转化为低价态(二价铁),是土壤中铁元素移动的主要途径。为了探讨三江平原不同土地利用类型Fe2+分布情况及影响因素,文章通过在三江平原典型白浆土区采取水田、旱田、草地、林地4种不同土地利用类型样点,对其Fe2+含量及其影响因子进行对比研究分析。结果表明:土壤表层(0~10cm)Fe2+含量高低顺序为水田>草地>旱田>林地,主要影响因子为水分状况和pH值(r=0.851,r=0.909,p<0.01),其中水田Fe2+含量(305.5mg·kg-1)明显高于林地和旱田(30~40mg·kg-1),是其含量的8~10倍;草地除表层(0~20cm)Fe2+含量低于水田外,以下各层含量均高于其它土地利用类型;草地、旱田、林地Fe2+含量垂直分布规律相似:表层(0~10cm)及白浆层(30~40cm)含量略高,40cm以下Fe2+含量持续缓慢递减,相关分析表明旱田、草地主要影响因子为土壤pH值(r=-0.871,r=0.795,p<0.05),林地影响因子相关性均不显著;水田垂直变化趋势与其它3种类型相比有所不同,表层最高达305.5mg·kg-1,至40cm深处急剧递减至35.2mg·kg-1,以下无明显变化,主要影响因子为水分状况和TOC(r=0.962,r=0.991,p<0.01)。
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采用菌丝生长速率法及孢子萌发法分别测定了细辛精油和4种化学药剂(30%嘧霉胺EC、50%双福生WP、75%百菌清WP、70%正品甲津托WP)对引起黄瓜灰霉病的灰葡萄孢菌菌丝生长和孢子萌发的抑制作用。结果表明,供试药剂对灰葡萄孢菌的菌丝生长和孢子萌发均有抑制作用,且对孢子萌发的抑制效果明显好于对菌丝生长的抑制效果;百菌清对灰葡萄孢菌菌丝生长的抑菌效果最好,EC50为1.6231mg/L;双福生对灰葡萄孢菌孢子萌发的抑制效果最好,EC50为0.0042mg/L;细辛精油对黄瓜灰葡萄孢菌的抑菌效果与其他4种化学药剂相比效果较差,对菌丝生长的EC50为159.580mg/L,对孢子萌发的EC50为71.1840mg/L,虽然其EC50偏高,但作为纯植物提取物,其抑菌中浓度低于160mg/L。
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The shape-con trolled synthesis of micrometer- sized gold nanocoralline was simply realized via a wet-chemical approach. The as-prepared hierarchical gold nanocorallines (HGNs) on the solid substrate were initially applied in SERS analysis with 4-aminothiophenol (4-ATP) as the probe molecule. The HGN-modified glass substrate exhibits a higher SERS effect (one order of magnitude higher) than the aggregated gold nanoparticle (similar to 25 nm)-modified glass substrate.
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通过自制的双功能螯合剂 4 ,7 二氯磺基苯 1,10啡啉 2 ,9二羧酸 (BCPDA)标记牛血清白蛋白(BSA)实验 ,对于BCPDA标记蛋白质的条件进行研究。结果表明 :BCPDA在温和的条件下能与蛋白质反应 ,并在一定条件下与铕离子形成稳定的BSA BCPDA Eu3+ 标记物。利用自建的分析方法 ,测定了标记过程的有关参数。并对标记物的某些光学特性进行了研究。
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The title complexes were synthesized and the crystal structures of their salts were determined by single-crystal X-ray structure analyses. Na-2[Zn-I(ida)(2)]. 7H(2)O: Triclinic, P1, a=0.523 4(2) nm, b=0.897 10(10) nm, c=1.069 10(10) nm, alpha=85.910(10)degrees, beta= 76.380(10)degrees, gamma=83.52(2)degrees, V=0.484 2(2) nm(3), Z=1. The complex anion [Zn-I (ida)(2)](2-) has a pseudo-octahedral structure in which the two N atoms: are in a trans configuration. Na-4[Hg-I(nta)(2)]. 7H(2)O: Monoclinic, C-c, a = 1.795 0(4) nm, b = 0.892 9(2)nm, c = 1.575 4(2) nm, beta = 92.78 (3)degrees, V = 2.526 2(9) nm(3), Z = 4. The complex anion [Hg-I (nta)(2)](4-) has a pseudo-bicapped-octahedral structure in which the two N atoms are in a trans configuration.
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The fragmentations of three bifunctional phenylether compounds including 2-(2, 6-dichloro)phenoxyl propionitrile, N-hydroxyl-4-butoxyl phenylacetyl amine(bufexamc) and 2-(1-methylethoxyl) phenol methylcarbamate (Propoxur) under electron impact ionization were reported, Metastable ion(MI) and collision-induced dissociation(CID) at a low energy have been used to study the fragmentation pathways from molecular ions. Apart from the simple bond cleavages, and the unimolecular dissociations via ion/neutral complex intermediate as a competitive mechanism were demonstrated, Moreover, the intramolecular hydrogen transfer and double hydrogen transfers in the fragmentations of these compounds were discussed in detail.
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报道了3种含双官能团苯基醚化合物2-(2,6-二氯苯氧基)丙睛、N-羟基-4-丁氧基苯乙酰胺、2-(1-甲基乙氧基)苯酚甲氨基甲酸酯的电子轰击质谱碎裂.用亚稳分析和低能碰撞诱导解离研究了3种化合物的分子离子碎裂规律,除简单的直接键断裂外,还证实经历了离子/中性(碎片)复合物中间体的单分子解离反应同时存在的竞争机理,解释了观察到的分子内单氢迁移、双氢迁移现象.