分布式文件系统Hadoop HDFS与传统文件系统Linux FS的比较与分析

对现有HDFS的设计架构进行分析,并借与LinuxFS架构的对比凸显HDFS的分布式特性。通过分析得出:现有的HDFS架构使用Java的Map界面,不利于任务的分解和并行处理,因此HDFS仅在数据的存储上实现分布式,数据处理依然是集中式的,这就形成了对NameNode的依赖,随着集群的扩大,NameNode的性能成为系统瓶颈,并提出了解决方向。

Kinetic Study of Prolidase Activity in Erythrocytes against Different Substrates Using Capillary Electrophoresis with Electrochemiluminescence Detection

Capillary electrophoresis (CE) with electrochemiluminescence (ECL) detection was used to explore the kinetics ofthe enzymatic reaction. The different effects ofreaction conditions including the concentration of Mn2l, incubation temperature and pH on PFOlidase (PLD, EC 3.4.13.9) activity in erythrocyte lysates against three different substrates, Gly-Pro, Val-Pro and Leu-Pro were investigated. Also, the effects of colchicine which can prevent or delay cancer ofliver on the PLD activity were studied.

Novel heteroleptic Cu-I complexes with tunable emission color for efficient phosphorescent light-emitting diodes

A series of orange-red to red phosphorescent heteroleptic Cu-I complexes (the first ligand: 2,2 '-biquinoline (bq), 4,4 '-diphenyl2,2 '-biquinoline (dpbq) or 3,3 '-methylen-4,4 '-diphenyl-2,2 '-biquinoline (mdpbq); the second ligand: triphenylphosphine or bis[2-(diphenylphosphino)phenyl]ether (DPEphos)) have been synthesized and fully characterized. With highly rigid bulky biquinoline-type ligands, complexes [Cu(mdpbq)(PPh3)(2)](BF4) and [Cu(mdpbq)(DPEphos)](BF4) emit efficiently in 20 wt % PMMA films with photoluminescence quantum yield of 0.56 and 0.43 and emission maximum of 606 nm and 617 nm, respectively. By doping these complexes in poly(vinyl carbazole) (PVK) or N-(4-(carbazol-9-yl)phenyl)-3,6-bis(carbazol-9-yl) carbazole (TCCz), phosphorescent organic light-emitting diodes (OLEDs) were fabricated with various device structures. The complex [Cu(mdpbq)(DPEphos)](BF4) exhibits the best device performance. With the device structure of ITO/PEDOT/ TCCz:[Cu(mdpbq)(DPEphos)](BF4) (15 wt %)/TPBI/LiF/Al (III), a current efficiency up to 6.4 cd A(-1) with the Commission Internationale de L'Eclairage (CIE) coordinates of (0.61, 0.39) has been realized. To our best knowledge, this is the first report of efficient mononuclear Cu complexes with red emission.

稀土资源的综合利用与高值化的建议

我国是稀土资源最丰富的　国家,不仅储量大,而且具有品　种全,质量好、分布广、易开采　等特点。据报道,我国稀土储量　930 0万吨(以REO计,含工业　及远景储量) ,占世界总储量　2 10 0 0万吨的4 4 .2 9% ,而独联　体为4 0 0 0万吨,占世界的　19.5 % ,位居第二;美国为　2 70 0万吨,占世界的12 .86 % ,　位居第三。我国稀土矿物类别　较多,主要矿物有氟碳铈矿、独　居石、磷钇矿、离子型稀土矿、　硅铍钇矿和褐钇钶矿等。经过　几十年的努力,特别是改革开　放以来我国稀土产业取得飞速　发展,已经形成从稀土开采、选　矿、冶炼到应用的比较完整的　工业体系,建立了一支热衷于　稀土的科研队伍,使我国成为　世界上最大稀土生产国和供应　国,在世界稀土市场上具有举　足轻重的作用。　但在我国稀土产业迅速发　展的同时,我们必须清醒地认　识到,我国稀土行业存在着许　多亟待解决的问题和面临的危　机。如乱采滥挖、资源浪费、重　复建设、无序竞争、产销失衡、　市场混乱、污染环境、缺乏创新　等。这些问题已经严重地制约　我国稀土产业的持续发展,以　下仅对某些问题提出意见和建　议。一、加强稀土资源的综合利用,保护...

含苯并咪唑基配体的稀土配合物的合成、结构及量子化学研究

合成了未见文献报道的N,N,N',N'-四[(2-苯并咪唑)甲基]乙二胺的丁基取代衍生物(BuEDTB)与稀土硝酸盐的配合物[M(BuEDTB)(NO3)2]·NO3·4H2O[M=La(1),Eu(2),Tb(3)],并用X射线衍射法测定了1的结构.晶体属三方晶系,空间群P3221,晶胞参数a=1.41353(9)nm,c=2.6264(4)nm;V=4.5447(9)nm3,Dc=1.189g/cm3,Z=3,F(000)=1686,μ=0.758 mm-1,R=0.0562,wR=0.1488.乙二胺上两个N原子及四个苯并咪唑各有一个N原子参与配位,两个硝酸根以双齿形式与稀土离子配位,第三个硝酸根不与金属离子配位.用ab initio HF方法研究了BuEDTB的电子结构.

Investigation of sandwiched gadolinium(III) complexes with tungstosilicates as potential MRI contrast agents

Two gadolinium-sandwiched complexes with tungstosilicates, K-13[Gd(SiW11O39)(2)] (Gd(SiW11)(2)) and K11H6[Gd2O3(SiW9O34)(2)] (Gd-3(SiW9)(2)), have been investigated by in vitro and in vivo experiments as potential contrast agents for magnetic resonance imaging (MRI). T-1-relaxivity of Gd(SiW11)(2)was 6.59 mM(-1) . s(-1) in aqueous solution and 6.85 mM(-1) . s(-1) in 0.725 mmol . L-1 bovine serum albumin solution at 25degreesC and 9.39 T, respectively. The corresponding T-1-relaxivity of Gd-3(SiW9)(2) was 12.6 and 19.3 mM(-1) . s(-1) per Gd, respectively. MRI for Sprague-Dawley rats showed longer and more remarkable enhancement in rat liver after i.v. injection of these two complexes: 39.4 +/- 3.9% and 57.4 +/- 11.6% within the first 30 min after injection, 31.2 +/- 2.6% and 39.9 +/- 7.6% in the next 60 min for Gd(SiW11)(2) and Gd-3(SiW9)(2) at doses of 0.081 and 0.084 mmol Gd/kg, respectively. Our preliminary in vitro and in vivo study indicates that Gd(SiW11)(2) and Gd-3(SiW9)(2) are favorable candidates for hepatic contrast agents for MRI. However, the two complexes exhibit higher acute toxicity and need to be modified and studied further before clinical use.

粉煤灰表面形貌和组成的电子显微镜/能量色散谱、聚焦离子束分析

用超级场发射电子显微镜 (FE SEM) ,扫描电子显微镜 /能量色散谱 (SEM/EDS)和聚焦离子束测试仪(FIB)等 ,对粉煤灰进行了表面形貌和元素组成分析。FIB显示粉煤灰大多为 0.3～0.5 μm的球状微粒 ;FE SEM则显示约有 88%的粉煤灰为0.3～1 μm的球状微粒 ,表面凹凸不平 ,主要为铝、硅、铁等元素的氧化物 ,其中铝、硅、铁和氧的质量分数分别为 20.5 %、23.6%、1.4%和50.9%。

Characterization of prolidase activity using capillary electrophoresis with tris(2,2'-bipyridyl)ruthenium(II) electrochemiluminescence detection and application to evaluate collagen degradation in diabetes mellitus

A new method for prolidase (PLD, EC 3.4.13.9) activity assay was developed based on the determination of proline produced from enzymatic reaction through capillary electrophoresis (CE) with tris(2,2'-bipyridyl)ruthenium(11) [Ru(bpy)(3)(2+)] electrochemiluminescence detection (ECL). A detection limit of 12.2 fmol (S/N = 3) for proline, corresponding to 1.22 x 10(-8) units of prolidase catalyzing for 1 min was achieved. PLD activity determined by CE-ECL method was in agreement with that obtained from the classical Chinard's one. CE-ECL showed its powerful resolving ability and selectivity as no sample pretreatmentwas needed and no interference existed. The clinical utility of this method was successfully demonstrated by its application to assay PLD activity in the serum of diabetic patients in order to evaluate collagen degradation in diabetes mellitus (DM). The results indicated that enhanced collagen degradation occurred in DM.

Surface enhanced Raman scattering of p-aminothiophenol self-assembled monolayers in sandwich structure fabricated on glass

A sandwich structure consisting of Ag nanoparticles (NPs), p-aminothiophenol (p-ATP) self-assembled monolayers (SAMs), and Ag NPs was fabricated on glass and characterized by surface enhanced Raman scattering (SERS). The SERS spectrum of a p-ATP SAM in such sandwich structure shows that the electromagnetic enhancement is greater than that on Ag NPs assembled on glass. The obtained enhancement factors (EF) on solely one sandwich structure were as large as 6.0 +/- 0.62x10(4) and 1.2 +/- 0.62x10(7) for the 7a and 3b(b(2)) vibration modes, respectively. The large enhancement effect of p-ATP SAMs is likely a result of plasmon coupling between the two layers of Ag NP (localized surface plasmon) resonance, creating a large localized electromagnetic field at their interface, where p-ATP resides. Moreover, the fact that large EF values (similar to 1.9 +/- 0.7x10(4) and 9.4 +/- 0.7x10(6) for the 7a- and b(2)-type vibration modes, respectively) were also obtained on a single sandwich structure of Au NPs/p-ATP SAMs/Ag NPs in the visible demonstrates that the electromagnetic coupling does not exist only between Ag NPs but also between Au and Ag NPs.

新型笼状同多钒酸盐[Ni(1,10′-phen)_3]_2·[V_2~ⅣV_8~ⅤO_(26)]的水热合成和晶体结构

尽管多金属氧酸盐 (POMs)的研究已有180多年的历史,但大量的POMs结构在最近几十年才被陆续解析出来[1～4].其中 ,同多钒酸盐由于钒配位几何形状的多样性,结构最为丰富 ,例如:[V4 O12 ]4-[5],[V5O14 ]3-[6],[V10 O2 8]6-[7] ,[V15O4 2 ]9-[8],[V13 O3 4 ]3-[9].值得注意的是,在这些化合物中,钒的化合价均处于最高氧化态+5价.由于+4价钒不易在溶液中(尤其是水中)稳定存在,因此在以往的常压溶液合成中具有混合价态的同多钒酸盐报道很少.与饱和价态的同多钒酸盐相比,混价多钒酸盐具有更为新奇的电荷分布和拓扑学几何构型,并且在 POMs的理论研究和抗病毒药物、电存储材料以及磁性材料等应用领域有特殊的研究和开发价值[1,10,11].因此,制备具有混价的新型同多钒酸盐一直倍受关注.近年来,水热合成技术的引入使同多钒酸盐合成化学迅速发展.水热体系提供了一个特殊的反应环境 [12 ],使制备各种具有混合价态的同多钒酸盐成为可能.Müller等[13]对这一领域开...

TEM studies on single crystal structure of syndiotactic poly(propene-co-butene-1)s

Themorphologies and structures of single crystals of syndiotactic poly(propene-co-1-butene) (PPBU) with 1-butene contents of 2.6, 4.2, 9.9, 16.2, and 47.9 mol % are studied by transmission electron microscopy and electron diffraction. The electron diffraction results show that the 1-butene units are included in the crystalline phase of the sPP homopolymer. A small amount of 1-butene (<4.2 mol %) has no significant influence on the antichiral chain packing of sPP. With increasing content of 1-butene units, an increasing packing disorder is observed in the PPBU copolymers. The antichiral packing model is, however, always the predominant chain packing structure of the copolymers with the analyzed composition. Bright-field electron microscopy observation shows that the PPBU single crystals exhibit always regular rectangular or lathlike shapes with preferred growth direction along their crystallographic b-axes owing to their packing features. The incorporated 1-butene units influence the crystallization behavior of sPP distinctly. With the increase of the 1-butene units, the aspect ratio of the single crystals increases. Furthermore, the typical transverse microcracks and ripples of the highly stereoregular sPP are no more so prominent for the copolymers. The microcracks are occasionally observed in the single crystals of copolymers with low 1-butene content (less than or equal to4.2 mol %), while transverse ripples are only seen in the crystals of the copolymer having a 1-butene content of 9.9 mol %. With a further increase in the content of 1-butene units, the copolymers behave like the low stereoregular sPP, where neither cracks nor ripples are observed any more.

联苯聚醚醚酮酮的结晶动力学的研究

通过dsc方法对新型聚芳醚酮联苯聚醚醚酮酮(PEEKDK)的等温及非等温熔融结晶动力学进行了研究，运用Avrami方程分析了其等温结晶行为，求得了等温结晶活化能，平衡熔点，成核参数，并与其它聚芳醚酮类聚合物进行了比较。同时，对PEEKDK的非等温结晶动力学也进行了研究。

Langmiur—Blodgett膜修饰电极和超分子组装电化学

本文对Langmiur-Boldgett膜修饰电极和有关电化学的基本特性与行为以及在电催化、光电化学和生物电化学传感器等方面的研究,应用超分子组装化学的观点进行了综述。

合成食用色素柠檬黄选择性电极的研制和应用

本文研究了以十二烷基三庚基碘化铵-柠檬黄缔合物为活性材料的PVC膜电极和涂丝电极,两电极对柠檬黄浓度在1.0×10~(-6)～1.0×10~(-3)mol/L间的响应符合Nernst关系式,斜率为20.0±1.0mV/PC(22℃),pH范围为4.0～9.4,电极的选择性、重现性和稳定性良好。对样品的测定结果与分光光度法测定结果基本一致。该方法简便、准确、可靠。

电感耦合等离子体原子发射光谱法中Kalman滤波法解析重叠谱线的研究

考察了Kalman滤波技术校正ICP-AES中谱线重叠干扰的潜力.以新息序列的平均平方和为评价函数优化扫描光谱的峰位,消除扫描过程中可能产生的波长定位误差,从而保证滤波结果的准确性,并使实际检出限显著改善.在中等分辨率光谱仪和扫描步长为1.5pm的条件下,滤波器能有效地分辨峰间距只有4.8pm且峰形基本相同的重叠线对.对峰间距为9.8pm的重叠线对,当线背比低至0.05左右时仍能获得满意结果.连续背景用理论描述,因而样品溶液和纯组分溶液的光谱扫描无需扣除溶剂空白.