一种自主移动运输机器人的设计与验证

在机器人搬运场景中,经常会出现货物实际姿态与预期不一致的情况,这时往往需要人工协作进行调整,工作效率和节拍因此受到影响。为解决以上问题,设计了一种自主移动运输机器人,可全向移动且具有新型摩擦轮-夹爪复合式取物结构及货物姿态调整结构,其控制系统采用同步定位与建图(Simultaneous Localization And Mapping,SLAM)等技术。通过pitch轴和yaw轴货物姿态调整实验确定了关键工作参数的最优值。最后进行了自主导航实验,结果表明该机器人在室内环境可实现自主导航。

Synthesis of K-doped three-dimensionally ordered macroporous Mn_(0.5)Ce_(0.5)O_δ catalysts and their catalytic performance for soot oxidation

A series of K-doped Mn0.5Ce0.5Oδ （K-MCO） catalysts with three-dimensionally ordered macroporous （3DOM） structure and different K loadings were successfully synthesized using simple methods. These catalysts exhibited well-defined 3DOM nanostructure, which consisted of extensive interconnecting networks of spherical voids. The effects of the calcination temperature and calcination time on the morphological characteristics and crystalline forms of the catalysts were systematically studied. The catalysts showed high catalytic activity for the combustion of soot. 3DOM 20% K-MCO-4h catalyst, in particular, showed the highest catalytic activity of all of the catalysts studied （e.g., Ts0 = 331 ~C and Smco2 = 95.3%）. The occurrence of structural and synergistic effects among the K, Mn, and Ce atoms in the catalysts was favorable for enhancing their catalytic activity towards the combustion of diesel soot. Furthermore, the temperatures required for the complete combustion of the soot （〈400 ℃） were well within the exhaust temperature range （175-400 ℃）, which means that the accumulated soot can be removed under the conditions of the diesel exhaust gas. These catalysts could therefore be used in numerous practical applications because they are easy to synthesize, exhibit high catalytic activity, and can be made from low cost materials.

自嵌式植生挡土墙在黄基支涌整治工程中的应用

自嵌式植生挡土墙是从加筋挡土墙延伸出的一种新型复合结构物,由自嵌式植生挡土块(鱼巢砖)、加筋材料、滤水填料和墙后土(砂)体组成。此结构依靠砖块间嵌锁功能和自身重量来防止滑动倾覆,达到稳定的作用,无须砂浆混凝土砌筑。自嵌式植生挡土墙技术具有整体连锁、安全可靠、施工简便快捷、减少占地、节省投资、耐久环保等优点,值得在河涌整治和城市防洪建设工程中进一步推广应用。

Structural Analysis of Peptides of PSⅡ Light-harvesting Complexes in Siphonous Green Algae, Codium fragile

Peptide composition and arrangement of 4 major light-harvesting complexes LHCP 1-3 and LHCP 3′ isolated from siphonous green algae (Codium fragile (Sur.) Hariot.) were investigated. LHCP 1 showed five main peptides, 34.4, 31.5, 29.5, 28.2 and 26.5 kD in SDS-PAGE, the 34.4 and 31.5 kD peptides were never found in higher plants. LHCP 3 contained the other four kinds of LHCP 1 peptides except 34.4 kD, while LHCP 3′ consisted of only 28.2 and 26.5 kD peptides. We found that 34.4, 28.2 and 26.5 kD peptides were easy to decompose from LHCP 1 when subjected to SDS-PAGE without pretreatment. They might be located at the exterior of LHCP 1, while the 31.5 and 29.5 kD peptides were at the central part. The 28.2 and 26.5 kD peptides often occurred in CPa, the center complex of PSⅡ. They are possibly the LHCⅡ peptides tightly associated with CCⅡ. According to the results described above, a peptide map of LHCP 1 was sketched.

Prediction of the thermo-elastic properties of knitted structural composites using FEM

It is a very important and complex task to estimate the thermo-elasticproperties of a textile structural composite. In this paper, the finite element method (FEM) wasused for the prediction of the orthotropic thermo-elastic properties of a composite reinforced byglass fiber knitted fabric. In order to define the final 3-D configuration of the loop reinforcingstructure, the interactions between the adjacent loops, the large displacement and the contactelements without friction were considered. The values predicted were compared with the experimentalresults.

The Calculation of Parameters for DNA Kinetic Structure Based on Monte-Carlo Multiple Integrals

Based on protein-DNA complex crystal structural data in up-to-date Nucleic Acid Database,the related parameters of DNA Kinetic Structure were investigated by Monte-Carlo Multiple Integrals on the base of modified DNA structure statistical mechanical model,and time complexity and precision were analyzed on the calculated results.

Construction and characterization of an experimental ISCOMS-based hepatitis B polypeptide vaccine

AIM: To characterize the biochemical and immunological properties of an experimental ISCOMS vaccine prepared from a novel therapeutic polypeptide based on T cell epitopes of HBsAg, and a heptatis B-ISCOMS was prepared and investigated. METHODS: An immunostimulating complexes(ISCOMS)-based vaccine containing a novel therapeutic hepatitis B polypeptide was prepared by dialysis method, and its formation was visualized by electron microscopy and biochemically verified by SDS-polyacrylamide gel electrophoresis. Amount of the peptide within ISCOMS was determined by Bradford assay, and specific CTL response was detected by ELISPOT assay. RESULTS: Typical cage-like structures of submicroparticle with a diameter of about 40nm were observed by electron microscopy. Results from Bradford assay showed that the level of peptide incorporation was about 0.33g.L(-1). At the paralleled position close to the sixth band of the molecular weight marker(3480kDa) a clear band was shown in SDS-PAGE analysis, indicating successful incorporation of polypeptide into ISCOMS. It is suggested that ISCOMS delivery system could efficiently improve the immunogenicity of polypeptide and elicit specific immune responses in vivo by the results of ELISPOT assay, which showed that IFN-gamma producing cells(specific CTL responses) were increased(spots of ISCOMS-treated group: 47+/-5, n =3; control group: 5+/-2, n =3). CONCLUSION: ISCOMS-based hepatitis B polypeptide vaccine is successfully constructed and it induces a higher CTL response compared with short polypeptides vaccine in vivo.

A facile method for fabrication of nano-structured Ni-Al_2O_3 graded coatings: Structural characterization

Powder charges of micron-size Ni and Al2O3were utilized to deposit nano-structured Ni-Al2O3composite coatings on analuminum plate fixed at the top end of a milling vial using a planetary ball mill.Composite coatings were fabricated using powdermixtures with a wide range of Ni/Al2O3mass ratio varying from1:1to plain Ni.XRD,SEM and TEM techniques were employed tostudy the structural characteristics of the coatings.It was found that the composition of the starting mixture strongly affects the Al2O3content and the microstructure of the final coating.Mixtures containing higher contents of Al2O3yield higher volume fractions of theAl2O3particles in the coating.Though Ni-Al2O3composite coatings with about50%of Al2O3particles were successfully deposited,well-compacted and free of cracks and/or voids coatings included less than20%(volume fraction)of Al2O3particles which weredeposited from powder mixtures with Ni/Al2O3mass ratios of4:1or higher.Moreover,mechanical and metallurgical bondings arethe main mechanisms of the adhesion of the coating to the Al substrate.Finally,functionally graded composite coatings withnoticeable compaction and integrity were produced by deposition of two separate layers under identical coating conditions.

Functional interplay among the flavivirus NS3 protease, helicase, and cofactors

Flaviviruses are positive-sense RNA viruses, and many are important human pathogens. Nonstructural protein 2B and 3 of the flaviviruses(NS2BNS3) form an endoplasmic reticulum(ER) membrane-associated hetero-dimeric complex through the NS2B transmembrane region. The NS2BNS3 complex is multifunctional. The N-terminal region of NS3, and its cofactor NS2B fold into a protease that is responsible for viral polyprotein processing, and the C-terminal domain of NS3 possesses NTPase/RNA helicase activities and is involved in viral RNA replication and virus particle formation. In addition, NS2BNS3 complex has also been shown to modulate viral pathogenesis and the host immune response. Because of the essential functions that the NS2BNS3 complex plays in the flavivirus life cycle, it is an attractive target for antiviral development. This review focuses on the recent biochemical and structural advances of NS2BNS3 and provides a brief update on the current status of drug development targeting this viral protein complex.

Organic-magnesium complex conversion coating on AZ91D magnesium alloy

An organic-magnesium complex conversion(OMCC)coating on AZ91D magnesium alloy was obtained by treating in a solution containing organic compounds.SEM,FESEM and XPS were used to examine the surface morphology,thickness and structure of the conversion coatings.The results show that the continuous and uniform conversion coating is deposited on AZ91D alloy and the main component of the coatings is organic compound containing benzene ring,which forms a chemical bond with magnesium.The polarization measurement and salt spray test show that the corrosion resistance of the conversion coating is much higher than that of traditional chromate conversion coating.

Exciplex formation and properties at organic solid interface in organic light emitting devices

The bilayer organic light emitting devices （OLEDs） using two common aromatic diamines as hole transporting materials （HTMs） and BBOT （2,5-bis（5-tert-butyl-2-benzoxazolyl）thiophene） as electron transporting material have been prepared, in which the electroluminescent spectra are different from the fluorescent spectra of each of the constituent materials. The electroluminescence is mainly attributed to exciplex confirmed by photoluminescence and electroluminescence measurements, and the type of exicplex is deternfined in terms of the energy level diagram of the bilayer devices, By comparing the molecular structures and energy levels of TPD and NPB, it is demonstrated that the structure of a molecule as well as its energy level has an effect on the exciplex formation.

Manufacture of Flax Reinforced PP Laminates and Research on the Tensile Properties

Flax fiber was used to reinforce Polypropylene （PP） owing to its lower impact on environment and suitable mechanical behaviors. To overcome the difficulty of penetrating fibers due to the high viscosity of thermo-plastic resin, PP filaments wrapping around the linen yam produced commingled yams, which were woven into fabrics as preforms to make laminates by optimum hot-pressing technology. The effects of fiber volume fraction, fabric density and structure on tensile properties of composites were researched through analyzing the tensile test results and the scanning electronic microscope （SEM） micrographs of fracture surface. Conclusions are drawn that the properties of laminates with fiber volume fraction of 0.50 are better than those with the other two fractions. For plain structure, the tensile properties in warp direction decrease according to the increase of weft density while in weft direction increase. For different fabric structures, properties of laminates with structures of plain 3, twill 2/2 and twill 3/1 increase gradually. And properties in weft direction are prior to those in warp direction for each laminate.

Preparation and Water-Gas Shift Catalytic Activities of the Perovskite Type Complex Oxide La_(1-x) Ce_xFeO_3

The perovskite type rare earth iron complex (REIC) oxide La 1-x Ce xFeO 3 is designed and prepared as water gas shift catalyst. Activity evaluation and heat resisting test show that the perovskite type compounds La 1-x Ce xFeO 3(·K) has a good thermal stability if x is less than or equal to 0.5 . But when x is greater than 0.5 , La 1-x Ce xFeO 3(·K) will turn out to be ceria and magnetite partially or completely at high temperature in the shift reaction atmosphere. In the case of x=0.5, the conversion of carbon monoxide is about 68% at 530 ℃. Potassium can greatly improve the low temperature activity, but slightly lower the high temperature activity, and has little impact on the thermal stability. La 0.5 Ce 0.5 FeO 3 (·K) is a promising chromium free high temperature shift catalyst.

Structure and stability of Li-Mn-Ni composite oxides as lithium ion sieve precursors in acidic medium

A series of spinel Li-Mn-Ni composite oxides with theoretical chemical formula of LiNixMn2-xO4 （0〈_x〈_1.0） were synthesized by liquid phase method. Their structure and morphology were characterized by X-ray diffractometry （XRD） and scanning electron microscopy （SEM）, respectively. The stability of these Ni-substituted spinel oxides prepared at different temperatures was investigated in acidic medium as well. The results show that Ni can be brought into the spinel framework completely to form well-crystallized product when x〈_0.5 and the optimized synthesis temperature is 800℃. LiNi0.4Mn1.6O4 prepared at 800℃ can maintain the spinel structure and morphology with Li extraction ratio of 30.37%, Mn extraction ratio of 8.78% and Ni extraction ratio of 1,82% during acid treatment. The incorporated Ni not only inhibits the dissolution of Mn, but also reduces the extraction of Li due to the lattice contraction

Research on the Geometry and Microstructure of the Coir Fiber

Coir fiber is derived from the coconut shells and considered to be an economical and natural material. In order to further extend its application fields,the geometry and microstructure of the coir fiber were thoroughly investigated in this research. The single fiber length measurement was carried out,and it was revealed that the length of the coir fiber was between 8 and 337 mm. Length distribution of the coir fiber was simulated by using the computer technology,and was found to be in coincidence with that of most natural fibers. The grouping measurement analysis was used to study the length-weight distribution and length-linear density distribution of the fiber. It was found that the average linear density was 27.89 tex and the linear density was between 18.265 and 70.442 tex. The length-weight distribution of the coir fiber showed a Poisson pattern,and the weight of fibers with the length between 50 and 230 mm accounted for 85.28% of the total fibers measured. In this research,scanning electron microscope (SEM) was applied to observe the morphological changes of coir fiber before and after alkali treatment;and the result shows that alkali treatment leads to the removal of lignin and pectin from both the cuticle and the inside walls,which is beneficial for the interfacial adhesion with polymer matrix in composite fabrication.

Chemical and structural biology of nucleic acids and protein-nucleic acid complexes for novel drug discovery

Since nucleic acids(DNA and RNA) play very important roles in cells,they are molecular targets of many clinically used drugs,such as anticancer drugs and antibiotics.Because of clinical demands for treating various deadly cancers and drug-resistant strains of pathogens,there are urgent needs to develop novel therapeutic agents.Targeting nucleic acids hasn’t been the mainstream of drug discovery in the past,and the lack of 3D structural information for designing and developing drug specificity is one of the main reasons.Fortunately,many important structures of nucleic acids and their protein complexes have been determined over the past decade,which provide novel platforms for future drug design and discovery.In this review,we describe some useful nucleic acid structures,particularly their interactions with the ligands and therapeutic candidates or even drugs.We summarize important information for designing novel potent drugs and for targeting nucleic acids and protein-nucleic acid complexes to treat cancers and overcome the drug-resistant problems.

Combination of NMR spectroscopy and X-ray crystallography offers unique advantages for elucidation of the structural basis of protein complex assembly

NMR spectroscopy and X-ray crystallography are two premium methods for determining the atomic structures of macro-biomolecular complexes.Each method has unique strengths and weaknesses.While the two techniques are highly complementary,they have generally been used separately to address the structure and functions of biomolecular complexes.In this review,we emphasize that the combination of NMR spectroscopy and X-ray crystallography offers unique power for elucidating the structures of complicated protein assemblies.We demonstrate,using several recent examples from our own laboratory,that the exquisite sensitivity of NMR spectroscopy in detecting the conformational properties of individual atoms in proteins and their complexes,without any prior knowledge of conformation,is highly valuable for obtaining the high quality crystals necessary for structure determination by X-ray crystallography.Thus NMR spectroscopy,in addition to answering many unique structural biology questions that can be addressed specifically by that technique,can be exceedingly powerful in modern structural biology when combined with other techniques including X-ray crystallography and cryo-electron microscopy.

Di- and tetranuclear heterometallic CuⅡ-LnⅢ complexes (Ln = Gd and Dy): Synthesis, structure and magnetic properties

Four 3d-4f heterometallic complexes, [CuⅡ-LnⅢ(bpt)2(NO3)3(MeOH)] (Ln = Gd, 1; Dy, 2; bptH = 3,5-bis(pyrid-2-yl)-l,2,4- triazole), [CuⅡ-LnⅢ(μ-OH)2(bpt)4C14 (H2O)2]·6H2O (Ln = Gd, 3; Dy, 4), have been synthesized under solvothermal condi- tions. X-ray structural analyses reveal that 1 and 2 are isostructural while 3 and 4 are isostructural. In each complex, the copper and gadolinium or dysprosium ions are linked by two triazolate bridges and form a CuⅡ-LnⅢ dinuclear unit. The intramolecu- lar Cu-Ln distances are 4.542, 4.525, 4.545 and 4.538 ] for 1, 2, 3 and 4, respectively. Two dinuclear CuLn units are bridged by two OH- groups into the zig-zag tetranuclear {cunzLnm2} structures with the Ln(Ⅲ)...Ln(Ⅲ) distances of 3.742 and 3.684 for 3 and 4, respectively. Magnetic studies show that the antiferromagnetic CulI-Lnm interactions occur in 1 (Jcu = -0,21 cm-1) and 2. The antiferromagnetic interaction occurs in complex 3 with JcuGa = -0.82 cm-1 and JcdGd = --0.065 cm-1, while domi- nant ferromagnetic interaction occurs in complex 4.

Recent progress on nanostructured conducting polymers and composites:synthesis,application and future aspects

Conducting polymers （CPs） have been widely investigated due to their extraordinary advantages over the traditional materials, including wide and tunable electrical conductivity, facile production approach, high mechanical stability, light weight, low cost and ease in material processing. Compared with bulk CPs, nanostructured CPs possess higher electrical conductivity, larger surface area, superior electro- chemical activity, which make them suitable for various ap- plications. Hybridization of CPs with other nanomaterials has obtained promising functional nanocomposites and achieved improved performance in different areas, such as energy sto- rage, sensors, energy harvesting and protection applications. In this review, recent progress on nanostructured CPs and their composites is summarized from research all over the world in more than 400 references, especially from the last three years. The relevant synthesizing experiences are outlined and abundant application examples are illustrated. The ap- proaches of production of nanostructured CPs are discussed and the efficacy and benefits of newest trends for the pre- paration of multifunctional nanomaterials/nanocomposites are presented. Mechanism of their electrical conductivity and the ways to tailor their properties are investigated. The re- maining challenges in developing better CPs based nanoma- terials are also elaborated.

Interface Characteristics of Wood-hybrid Composites

In order to understand the current interface characteristics of wood-hybrid composites, this paper starts off from the concept of composite interface and general theory of interface form, then the inner-surface and microstructure of wood and the interface characteristics of composites, such as wood- inorganic, wood- plastic and wood- metal made by electroless plating technique, are concluded and discussed in detail. Meanwhile, on the basis of that, some points of view about how to develop the wood-hybrid composites interface research in the future are also proposed.