Surface relief resonant Brewster niters with multiple channels

In this paper, a new type of resonant Brewster filters (RBF) with surface relief structure for the multiple channels is first presented by using the rigorous coupled-wave analysis and the S-matrix method. By tuning the depth of homogeneous layer which is under the surface relief structure, the multiple channels phenomenon is obtained. Long range, extremely low sidebands and multiple channels are found when the RBF with surface relief structure is illuminated with Transverse Magnetic incident polarization light near the Brewster angle calculated with the effective media theory of sub wavelength grating. Moreover, the wavelengths of RBF with surface relief structure can be easily shifted by changing the depth of homogeneous layer while its optical properties such as low sideband reflection and narrow band are not spoiled when the depth is changed. Furthermore, the variation of the grating thickness does not effectively change the resonant wavelength of RBF, but have a remarkable effect on its line width, which is very useful for designing such filters with different line widths at desired wavelength.

New generation of two-dimensional spintronic systems realized by coupling of Rashba and Dirac fermions

Intriguing phenomena and novel physics predicted for two-dimensional (2D) systems formed by electrons in Dirac or Rashba states motivate an active search for new materials or combinations of the already revealed ones. Being very promising ingredients in themselves, interplaying Dirac and Rashba systems can provide a base for next generation of spintronics devices, to a considerable extent, by mixing their striking properties or by improving technically significant characteristics of each other. Here, we demonstrate that in BiTeI@PbSb2Te4 composed of a BiTeI trilayer on top of the topological insulator (TI) PbSb2Te4 weakly- and strongly-coupled Dirac-Rashba hybrid systems are realized. The coupling strength depends on both interface hexagonal stacking and trilayer-stacking order. The weakly-coupled system can serve as a prototype to examine, e.g., plasmonic excitations, frictional drag, spin-polarized transport, and charge-spin separation effect in multilayer helical metals. In the strongly-coupled regime, within similar to 100 meV energy interval of the bulk TI projected bandgap a helical state substituting for the TI surface state appears. This new state is characterized by a larger momentum, similar velocity, and strong localization within BiTeI. We anticipate that our findings pave the way for designing a new type of spintronics devices based on Rashba-Dirac coupled systems.

Bundles of polytwins as meta-elastic domains in the thin polycrystalline simple multi-ferroic system PZT.

We used enhanced piezo-response force microscopy (E-PFM) to investigate both ferroelastic and ferroelectric nanodomains in thin films of the simple multi-ferroic system PbZr(0.3)Ti(0.7)O(3) (PZT). We show how the grains are organized into a new type of elastic domain bundles of the well-known periodic elastic twins. Here we present these bundle domains and discuss their stability and origin. Moreover, we show that they can arrange in such a way as to release strain in a more effective way than simple twinning. Finally, we show that these bundle domains can arrange to form the macroscopic ferroelectric domains that constitute the basis of ferroelectric-based memory devices.

A new protein structure of P-II class snake venom metalloproteinases: it comprises metalloproteinase and disintegrin domains

A new metalloproteinase-disintegrin, named Jerdonitin, was purified from Trimeresurus jerdonii venom with a molecular weight of 36 kDa on SDS-PAGE. It dose-dependently inhibited ADP-induced human platelet aggregation with IC50 of 120 nM. cDNA cloning and sequencing revealed that Jerdonitin belonged to the class II of snake venom metalloproteinases (SVMPs) (P-II class). Different from other P-II class SVMPs, metalloproteinase and disintegrin domains of its natural protein were not separated, confirmed by internal peptide sequencing. Compared to other P-II class SVMPs, Jerdonitin has two additional cysteines (Cys219 and Cys238) located in the spacer domain and disintegrin domain, respectively. They probably form a disulfide bond and therefore the metalloproteinase and disintegrin domains cannot be separated by posttranslationally processing. In summary, comparison of the amino acid sequences of Jerdonitin with those of other P-II class SVMPs by sequence alignment and phylogenetic analysis, in conjunction with natural protein structure data, suggested that it was a new type of P-II class SVMPs. (C) 2003 Elsevier Inc. All rights reserved.

Multiwall nanotubes, multilayers, and hybrid nanostructures: new frontiers for technology and Raman spectroscopy.

Technological progress is determined, to a great extent, by developments in material science. Breakthroughs can happen when a new type of material or new combinations of known materials with different dimensionality and functionality are created. Multilayered structures, being planar or concentric, are now emerging as major players at the forefront of research. Raman spectroscopy is a well-established characterization technique for carbon nanomaterials and is being developed for layered materials. In this issue of ACS Nano, Hirschmann et al. investigate triple-wall carbon nanotubes via resonant Raman spectroscopy, showing how a wealth of information can be derived about these complex structures. The next challenge is to tackle hybrid heterostructures, consisting of different planar or concentric materials, arranged "on demand" to achieve targeted properties.

Full-color emission from In2S3 and ln(2)S(3): Eu3+ nanoparticles

New observations on the luminescence Of In2S3 and europium-doped In2S3 nanoparticles show a green (5 10 nm) emission from In2S3 and In1.8Eu0.2S3 nanoparticles while a blue (425 nm) emission is observed from ln(1.6)Eu(0.4)S(3) nanoparticles. Both the blue and green emissions have large Stokes shifts of 62 and 110 nm, respectively. Excitation with longer-wavelength photons causes the blue emission to shift to a longer wavelength while the green emission wavelength remains unchanged. The lifetimes of both the green and blue emissions are similar to reported values for excitonic recombination. When doped with Eu3+, in addition to the broad blue and green emissions, a red emission near 615 nm attributed to Eu3+ is observed. Temperature dependences on nanoparticle thin films indicate that with increasing temperature, the green emission wavelength remains constant, however, the blue emission shifts toward longer wavelengths. Based on these observations, the blue emission is attributed to exciton recombination and the green emission to Indium interstitial defects. These nanoparticles show full-color emission with high efficiency, fast lifetime decays, and good stability; they are also relatively simple to prepare, thus making them a new type of phosphor with potential applications in lighting, flat-panel displays, and communications.

A new technique for boosting efficiency of silicon solar cells

A new type of photovoltaic system with higher generation power density has been studied in detail. The feature of the system is a V-shaped module (VSM) with two tilted monocrystalline solar cells. Compared to solar cells in a flat orientation, the VSM enhances external quantum efficiency and leads to an increase of 31% in power conversion efficiency. Due to the VSM technique, short-circuit current density was raised from 24.94 to 33.7mA/cm(2), but both fill factor and open-circuit voltage were approximately unchanged. For the VSM similar results (about 30% increase) were obtained for solar cells fabricated by using mono-crystal line silicon wafers with only conventional background impurities. (c) 2004 Elsevier B.V. All rights reserved.

Ferromagnetism in Mn and Cr doped GaN by thermal diffusion

Doping of magnetic element Mn and Cr in GaN was achieved by thermal diffusion. The conductivity of the samples, which were all n-type, did not change significantly after the diffusion doping. X-ray diffraction measurements revealed no secondary phase in the samples. Experiments using superconducting quantum interference device (SQUID) showed that the samples were ferromagnetic at 5 and 300 K, implying the Curie temperature to be around or over 300 K, despite their n-type conductivity. (c) 2004 Elsevier B.V. All rights reserved.

DISORDER POINT FOR 2D ELECTRONS IN A HALF-FILLED LANDAU-LEVEL

Short-range correlations of two-dimensional electrons in a strong magnetic field are shown to be triangular in nature well below half-filling, but honeycomb well above half-filling. The half-filling point is thus proposed, and qualitatively confirmed by three-body correlation calculations, to be a new type of disorder point where short-range correlations change character. A wavefunction study also suggests that nodes become unbound at half-filling. Evidence for incompressibility but deformability of the half-filling state earlier suggested by Fano, Ortolani and Tosatti, is also presented and found to be in agreement with recent experiments.

A High Performance AlGaN/GaN HEMT with a New Method for T-Gate Layout Design

We propose and fabricate an A1GaN/GaN high electron mobility transistor （HEMT） on sapphire substrate using a new kind of electron beam （EB） lithography layout for the T-gate. Using this new layout,we can change the aspect ratio （ratio of top gate dimension to gate length） and modify the shape of the T-gate freely. Therefore, we obtain a 0.18μm gate-length AlGaN/GaN HEMT with a unity current gain cutoff frequency （f_T） of 65GHz. The aspect ratio of the T-gate is 10. These single finger devices also exhibit a peak extrinsic transconductance of 287mS/mm and a maximum drain current as high as 980mA/mm.

丁香和升麻的化学成分研究

本论文由三部分共四章组成。第一部分介绍丁香化学成分的研究成果，第二部分为升麻的化学成分研究，第三部分综述了环菠萝蜜烷三萜结构和活性关系的研究现状。 第一部分包括第一和第二章。第一章介绍了丁香（Eugenia caryophyllataThunb.）花蕾的化学成分和结构鉴定。采用正、反相硅胶柱层析等各种分离方法，从其乙醇提取物的乙酸乙酯萃取物和正丁醇萃取物中共分离出34 个化合物，它们的结构类型分属黄酮、三萜、鞣质等。其中1 个为新的酚苷类化合物，其结构经波谱分析鉴定为2-O-(6'-O-没食子酰基)-b-D-葡萄糖基苯甲酸甲酯（24），另外还有12 个化合物为首次从该植物中分离得到。第二章介绍了丁香挥发油的气相色谱- 质谱联用（ GC-MS ）和正丁醇萃取物的高效液相色谱- 质谱联用（HPLC-MS/MS）分析，尝试简单快速地检测丁香挥发油及极性部分的主要化学成分的方法。 第二部分为第三章。本章介绍了传统中药升麻（Cimicifuga foetida L.）根部乙醇提取物化学成分的分离纯化和结构鉴定。通过正、反相硅胶柱层析等分离纯化方法和MS、NMR 等波谱解析技术，共分离鉴定了20 个化合物，主要为环菠萝蜜烷三萜，其中5 个新三萜化合物分别鉴定为cimicidol-3-one（38）、3'-O-乙酰基升麻苷H-1（41）、2'-O-乙酰基升麻苷H-1（42）、(3b,12b,16b)-12-乙酰氧-16,23-环氧-9,19-环羊毛甾烷-22-烯-24-酮3-O-b-D-吡喃木糖苷（44）和升麻碱（54）。新化合物54 为结构新颖的环菠萝蜜烷三萜皂苷生物碱，这是首个发现的具有环菠萝蜜烷三萜骨架的生物碱，也是从升麻属植物中发现的第一个三萜生物碱，它的结构通过多种波谱解析，特别是2D-NMR 的充分应用，并结合化学降解和反应得到证实。此外，还介绍了分离得到的一种具有明显抑制破骨细胞活性的化合物(QS29)的体外活性研究。 第三部分即第四章，综述了升麻属植物中环菠萝蜜烷三萜与其生物活性的构效关系研究现状。 This dissertation consists of three parts. In the first and the second parts, thechemical constituents from the flower buds of Eugenia caryophyllata and therhizomes of Cimicifuga foetida were reported. The third part is a review on astructure-activity relationship of the cycloartane triterpenoid from Cimicifuga species. The first part is composed of two chapters. The chapter 1 is about the isolationand identification of the chemical constituents from the flower buds of E.caryophyllata. A new phenolic glucoside gallate, methyl 2-O-(6’-O-galloyl)-b-D-glucopyranosylbenzoate (24), together with thirty-three known compounds has beenisolated from the ethanol extract of the flower buds of E. caryophyllata throughrepeated column chromatography on normal and reversed phase silica gel. Thestructure of the new compound was elucidated on the basis of spectral and chemicalevidence. Those kno wn compounds were belonged to flavone, triterpenoid, tannin andsome simple compounds. Among them, 12 compounds were isolated from the titleplant for the first time. The second chapter describes the capillary GC-MS analysis ofthe volatile components and the HPLC-MS/MS analysis of the polar constituents fromthe flower buds of E. caryophyllata, in order to detect the main constituents in thecrude extract rapidly and precisely. The third chapter is about the chemical constituents of the rhizomes C. foetida, atraditional Chinese medicine which was used as anti-inflammatory, analgesic andantipyretic agents. Our investigation of the bioactivities constituents of the rhizomesof C. foetida led to the isolation of five new cycloartane triterpenoids, which werecharacterized as cimicidol-3-one (38), 3'-O-acetyl cimicifugoside H-1 (41),2'-O-acetyl cimicifugoside H-1 (42), (3b,12b,16b)-12-acetoxy-16,23-epoxy-9,19-cyclolanost-22-ene-24-one 3-O-b-D-xylopyranoside (44) and cimicifugadine (54),along with fifteen known compounds through repeated column chromatography onnormal and reversed phase silica gel. Among them, 54 is a novel cycloartanealkaloid and first discovered as a new type alkaoid from nature. The structures ofthese compounds were elucidated on the basis of spectral and chemical evidence, andcimicidol-3-one was confirmed by X-ray crystallography analysis. Moreover, onecompound exhibited strong anti-osteoporosis activity in vitro experiment. The fourth part is a review on a structure-activity relationship analysis of thecycloartane triterpenoid from Cimicifuga species.

厌氧好氧一体化生物反应器处理发酵废水的中试研究

一体化反应器由于投资少、占地小、管理运行方便等优点而备受青睐。但现有的一体化反应器大都适用于处理中低浓度废水，耐受负荷普遍偏低。本课题研制出新型高效的厌氧好氧一体化生物反应器，旨在通过反应器结构优化、高效微生物载体研制、配合高效微生物菌剂技术处理中高浓度有机废水，实现高效和低耗，降低设备造价，提高反应器运行稳定性。 首先开展了菌剂对废水的适配试验。采用15种不同的微生物菌剂，以葡萄糖配水、中药提取废水、啤酒废水、氨氮配水为基质，分别测定了微生物菌剂的耗氧速率和厌氧比产甲烷速率，以其为指标比较了各菌剂对废水的适配性。根据结果选择活性高的14＃、8＃、10＃菌剂，在试验室进行了菌剂对废水的连续处理试验，取得良好的处理效果，为菌剂在厌氧好氧一体化生物反应器的小试、中试中的应用奠定了基础。 经小试研究后，又对厌氧好氧一体化生物反应器进行了处理发酵废水的中试研究。试验结果表明，反应器启动快，系统有机负荷2.72 kgCODm-3d-1时整个反应器去除率保持在84.5％～93.19％，在30多天内一次启动成功。冲击负荷试验中，系统总有机负荷最高可达到8.88 kgCODm-3d-1，系统去除率稳定在88.10％～96.88%，说明反应器处理效率高，抗冲击能力强。稳定运行期间，COD去除率可达90％以上，各项指标都能达到国家排放标准。 此外，对反应器配套系统高效菌剂、高分子复合颗粒载体进行了研究。结果显示，菌剂与反应器适配良好，各功能区形成了丰富、高活性的微生物，厌氧区颗粒污泥TS高达83.9 gL-1，VS/TS为56.9％～57.4％，比产甲烷活性为280～350 mLCH4 gvss-1d-1；好氧区固定化微生物TS高达1.921 gL-1，VS/TS为94.02～94.30％。对载体性能的研究表明，此高分子复合颗粒载体密度适中，易于流化，不易流失；粗糙多空，易于挂膜；且无生物毒害作用，稳定安全，是一种优良的生物载体。反应器各功能区对废水的降解过程分析，说明了反应器、菌剂、载体适配良好，在其协同作用下，实现了污染物的高效降解。 The integrated reactors were popular because of their characteristics such as little investment, small occupation of land, convenient of manage and running etc. But the present integrated reactors were mostly applied for treating wastewater of low concentration, the load tolerance was generally on the low side. A new type integrated anaerobic-aerobic bio-reactor was developed, which was conducted to treating organic wastewater of middle or high concentration by optimization of reactor structure, development of efficient microbe carrier and adaptation of high active microbial blends, to achieve high efficiency and low consume, reduce equipment cost, enhance running stabilization of reactor. The adaptability test of microbial blends on different wastewater was carried on firstly. Oxygen consumption rate and anaerobic specific activity of methane producing of 15 different microbial blends were measured separately taking glucose artificial wastewater, Chinese herb extracting wastewater, brewery wastewater and ammonia nitrogen artificial wastewater as substrate, by which the adaptabilities of different microbial blends to wastewater were compared. According to the results high active microbial blends 14#, 8# and 10# were selected and used in the continuous treatment of wastewater in the laboratory and had obtained good effect, which had laid a foundation for application microbial blends to small scale test and pilot test of integrated anaerobic-aerobic bio-reactor. After the small scale test, the pilot test of the integrated anaerobic-aerobic bio-reactor treating fermentation wastewater was carried on. The test results showed fast initiation of the reactor. When system organic load reached 2.72 kgCODm-3d-1the COD removal rate of the reactor was stable between 84.5%～93.19% and it initiated successfully in more than 30 days at a time. In the load shock test the maximum organic load of system could reach to 8.88 kgCODm-3d-1 and the COD removal rate could be stable between 88.10%~96.88% which indicated that the reactor was efficient for treating wastewater and had strong resistance to shock load. At stable running period the COD removal rate of the reactor was over 90% and each index of wastewater could reach to the national discharge standards. In addition, the high active microbial blends and the macromolecule compound granule carrier, the matching system of the reactor was studied. It showed that the microbial blends adapted well to the reactor and abundant and high active microbes were formed in each functional field. The TS of granule sludge in anaerobic field was as high as 83.9 gL-1, the VS/TS was 56.9%~57.4%, the specific activity of methane producing was 280~350 mLCH4 gvss-1d-1. And the TS of immobilized biological granule was as high as 1.921 gL-1, the VS/TS was 94.02%~94.30%. Study on the carrier showed that the self-made macromolecular compound granule carrier was moderate of density, easy of fluidization, unease of running off, rough and porous, easy of films fixation, no bio-toxic, stable and safe, was a kind of superior carrier. Analysis of degradation process in each functional field confirmed the reactor, microbial blends and carriers were in good adaptation and wastewater was decontaminated by their cooperation.

真菌单宁酶发酵五倍子和有机溶剂中酶法合成没食子酸丙酯的研究

本文报告了丝状真菌单宁酶发酵五倍子及有机溶剂中酶法合成没食子酸丙酯的研究。利用单宁和/或五倍子诱导丝状真菌产生单宁 酶的原理，借助二级发酵程序，对从天然源得到的75株菌进行了生物转化实验研究。选择出既能水解单宁或五倍子成没食子酸，又 能把没食子酸和丙醇合成没食子酸丙酯，而且生物催化活性都较高的1株菌，这株菌经初步鉴定为黑曲霉(Aspergillus niger No.17)。随后对它开展了产酶条件和参数优化实验，得出了最佳培养条件。立足于参数优化实验方案的基础上，经由液体培养发酵 制备单宁酶制剂，并把该酶通过化学手段共价结合到一种新型载体—聚乙烯醇和戊二醛反应生成的缩醛上，制备得到固定化单宁酶 。这种固定化生物催化剂在两种有机介质体系中都具有逆向催化合成没食子酸丙酯的能力。最后建立起来一条有效可行的微生物酶 法制备没食子酸的技术途径，没食子酸产率达到70%。对这种物质进行元素 分析：含C,49.45%;含H,3.63%。它的熔点为237℃～243 ℃，三种溶剂系统的TLC均只给出一个斑点。这些数据都与标准品一致。有机溶剂中酶法合成没食子酸丙酯的技术途径已经建立。 水溶性单宁酶在潜溶剂体系中也能催化上述酯化反应，反应混合物中的PG浓度为16.4mmol/L，制备薄层被用于分离反应混合物所含 的PG，这种产物被红外、质谱及三种溶剂系统的TLC等方法鉴定，确证为目标产物。在这一学位论文的实验研究过程中，还包括一 些生化分析方法的建立和应用，这些方法用于鉴定底物和产物及测定它们的浓度，其内容主要包括TLC定性/半定量分析、元素分析 、质谱、红外等手段的综合运用。本工作为开发我国特有的天然产物资源—五倍子的生物化工加工技术及非水相生物催化技术的开 发，提供了有用的基础数据资料，具有应用基础研究工作的重要性。In this thesis, the studies on the fermentation of Chinese gallotannin by filamentous fungi with tannase activity and enzymatic synthesis of propyl gallate(PG) in organic solvents were described through these biocatalysts. Based on the principles of induction enzyme, the tannase produced from filamentous fungi by adding tannic acid(TA) and/or Chinese gallotannin into media was investigated, and the screening experiments of bioconversion were done with 75 strains by means of a two-stage fermentation procedure. These strains were isolated with the enrichment culture technique from natural sources. Hence we selected one strain (Aspergillus niger No.17) that can not only catalyze the hydrolyses of TA and/or Chinese gallotannin into gallic acid(GA) in the liquid cultures, but also be used to synthesize PG from propanol and GA in the non-aqueous media. At the same time both of its biocatalytical activities were higher. This strain was calssified to be Aspergillus niger by the primary identification. Then optimum conditions for production of the tannase and its parameters were examined. In this way, one set of optimum culture conditions was selected. Making use of the optimum proposal, the tanase was prepared through a liquid fermentation procedure. The enzyme was convalently coupled to a new type of carrier which was made chemically from polyvinyl alcohol(PVA)and glutaraldehyde. The immobilized enzymes were able to synthesize PG reversely in two organic media. Finally, an effective enzymatic technique for production of GA was developed. The yield of GA products was up to 70%。Element analysis for this substance: calce: C, 49.42%; H, 3.56%; found: C, 49.45%, H, 3.63%. Its melting point was 237℃～ 243℃ and TLCs on three solvent systems gave only one spot respectively. These data were identical with theauthentic GA. The enzymatic synthesis of PG in organic solvents was extablished with reverse route of tannase catalytical hydrolysis. Aqueous enzyme perparation also catalyzed above esterification in a buffer system. The PG concentration in the reaction mixture was 16.4mmol/L. The reparative-scale TLC was used to isolate PG from the reaction mixture. This product separated was identified by IR, MS and TLC on three solvent systems. In this study of thesis, some biochemical analytical mehtods were developed and used to identify substrates and products, and to determinate their concentration. These methods, including TLC qualitative/half quantitative analysis, element analysis, MS, IR and so on, were useful, available and performable. This work provided basic data and information for developing the biochemical engineering and bio-processing of Chinese gallotannin-a special natural resource in China and the non-aqueous phase biocatalysis. Thus, this study possesses importance in the applied and basic research work.

Prolate and oblate shape coexistence in Pt-188

A standard in-beam gamma-spectroscopy experiment for Pt-188 is performed via the Yb-176(O-18, 6n) reaction at beam energies of 88 and 95 MeV, and the level scheme for (188) Pt is established. Prolate and oblate shape coexistence has been demonstrated to occur in Pt-188 by applying the projected shell model. The rotation alignment of i(13/2) neutrons drives the yrast sequence changing suddenly from prolate to oblate shape at angular momentum 10th, indicating likely a new type of shape phase transition along the yrast line in Pt-188.

Investigation of PL properties of C-doped SiO2/Si samples after high energy Pb ion irradiation

Amorphous SiO2 thin films with about 400-500 nm in thickness were thermally grown on single crystalline silicon. These SiO2/Si samples were firstly implanted at room temperature (RT) with 100 keV carbon ions to 2.0 x 10(17),5.0 X 10(17) or 1.2 x 10(18) ions/cm(2), then irradiated at RT by 853 MeV Pb ions to 5.0 x 10(11), 1.0 X.10(12) 2.0 x 10(12) or 5.0 x 10(12) ions/cm(2), respectively. The variation of photoluminescence (PL) properties of these samples was analyzed at RT using a fluorescent spectroscopy. The obtained results showed that Pb-ion irradiations led to significant changes of the PL properties of the carbon ion implanted SiO2 films. For examples, 5.0 x 10(12) Pb-ions/cm(2) irradiation produced huge blue and green light-emitters in 2.0 x 10(17) C-ions/cm(2) implanted samples, which resulted in the appearance of two intense PL peaks at about 2.64 and 2.19 eV. For 5.0 x 10(17) carbon-ions/cm(2) implanted samples, 2.0 x 10(12) Pb-ions/cm(2) irradiation could induce the formation of a strong and wide violet band at about 2.90 eV, whereas 5.0 x 10(12) Pb-ionS/cm(2) irradiation could,create double peaks of light emissions at about 2.23 and 2.83 eV. There is no observable PL peak in the 1.2 x 10(18) carbon-ions/cm(2) implanted samples whether it was irradiated with Pb ions or not. All these results implied that special light emitters could be achieved by using proper ion implantation and irradiation conditions, and it will be very useful for the synthesis of new type Of SiO2-based light-emission materials.