The effect of nanohybrid materials on the pour-point and viscosity depressing of waxy crude oil

The pipeline transportation of waxy crude oil is a problem both at home and abroad.In this paper,a novel nanohybrid pour-point depressant (PPD) was used to decrease the pour point and viscosity of waxy crude oil.The pour point and apparent viscosity of waxy crude oil was decreased significantly upon addition of the nanohybrid PPD,and the long-term stability of the nanohybrid PPD was superior to that of a conventional ethylene-vinyl acetate copolymer PPD.Polarized optical microscopy and X-ray diffraction were used to study the effect of the nanohybrid PPD on the crystallization of crude oil.Addition of the nanohybrid PPD reduced the amount of wax crystals,prevented their aggregation,and reduced the temperature at which the crude oil started to crystallize.The significant effect of this nanohybrid PPD on the pour point and viscosity depressing of crude oil is of great importance for facilitating the safe,efficient and energy-minimized transportation of waxy crude oil.     

Effect of Ni addition on the glass-forming ability and soft-magnetic properties of FeNiBPNb metallic glasses

The effect of Ni addition on the glass-forming ability (GFA) and soft-magnetic properties of an (Fe1-xNix)75.5B14.5P7Nb3 (x=0-0.6) alloy system were investigated. We found that the addition of Ni was effective in allowing the alloy to approach a eutectic point as well as increasing the thermal stability of the supercooled liquid. By increasing the amount of Ni,the supercooled liquid region (ΔTx),the reduced glass transition temperature Trg (Tg/Tl) and the Y parameter [Tx/(Tg+Tl)] increased from 49 to 75 K,0...     

Construction of an electronic physical map of Magnaporthe oryzae using genomic position-ready SSR markers

Magnaporthe oryzae is a model for plant pathogenic filamentous fungi. We have assembled a simple sequence repeat (SSR)-based physical map of the species, using in silico sequence data. A set of 120 SSR markers was developed from the genomic sequence of the reference isolate 70-15. These markers were readily amplified from the genomic DNA of other isolates, and high levels of allelic variation characterised the parental isolates of the two crosses tested. All the markers were locatable to one of the seven M. oryzae chromosomes. An SSR-based physical in silico map was constructed, and pre-existing SSR and RFLP loci were integrated into the map, along with 23 Avr (avirulence) genes and two other genes of importance to the plant/pathogen interaction. This map provides a platform for population genetics and functional genomics studies in the model pathogen, and even in other evolu- tionally related pathogens.     

Formation and biocorrosion behavior of Zr-Al-Co-Nb bulk metallic glasses

Ni-and Cu-free Zr-Al-Co-Nb glassy alloys with different Nb and Co contents were synthesized by melt spinning and copper mold casting.The effects of Nb addition to partially replace Co in the Zr55Al20Co25 glassy alloy on the glass-forming ability,thermal properties,in-vitro biocorrosion behavior and surface wettability of the metallic glasses were investigated.Although addition of Nb up to 5 at.% slightly decreased the supercooled liquid region and the glass-forming ability(GFA),the alloys could be casted in a bulk glassy rod form with diameters up to 3mm.The Zr-Al-Co-Nb glassy alloys were spontaneously passivated with low passive current densities in phosphate buffered saline and Hanks’ solution.Substitution of "toxic" Co by Nb is effective in improved the corrosion resistance of the Zr-Al-Co glassy alloy.Water contact angle measurements showed that Nb addition increased the hydrophilicity of the glassy alloys,which may enhance cell adhesion of the alloys in biomedical applications.     

Centimeter-scale-diameter Co-based bulk metallic glasses with fracture strength exceeding 5000 MPa

Co48-xFexCr15Mo14C15B6Er2 (x = 2.5 and 5) bulk metallic glasses (BMGs) with critical size (dc) up to 15 mm in diameter were synthesized by copper mold casting. Co43Fe5Cr15Mo14C15B6Er2 BMG has a wide supercooled liquid region (84 K) and ultrahigh fracture strength exceeding 5000 MPa,which is the highest value for reported metallic glasses with dc exceeding 1 cm. Furthermore,the Poisson ratio,Young modulus,shear modulus and bulk modulus of this alloy were evaluated to be 0.31,217 GPa,82 GPa and 214 GPa,respectively. The ideal configurational entropy of Co48-xFexCr15Mo14C15B6Er2 (x = 0 and 5) has been calculated. The introduction of the similar element Fe in the Fe-free Co-Cr-Mo-C-B-Er alloy will be beneficial to increasing the ideal config-urational entropy and depressing the critical cooling rate to achieve greater glass-forming ability. The combination of superior glass-forming ability and ultrahigh fracture strength makes the present Co48-xFexCr15Mo14C15B6Er2 (x = 2.5 and 5) BMGs promising candidates as advanced structural materials.     

Thermoelectric properties of tungsten ceramics prepared from nanopowder precursors

Tungsten trioxide ceramics were prepared from nm-sized powder precursors. Thermoelectric properties of samples were investigated. The results demonstrated that ceramics prepared in this manner have improved electrical conductivity and Seebeck coefficient values. The power factor of these samples also improved markedly, the largest power factor being 0.027 μW m-1K-2 at 773 K.     

Genetic and physical mapping of AvrPi7, a novel avirulence gene of Magnaporthe oryzae using physical position-ready markers

Rice blast, caused by the fungal pathogen Magnaporthe oryzae, is one of the most devastating crop diseases worldwide. The avirulence gene corresponding to rice blast resistance gene Pi7 in field isolate CHL346 was inherited as a single gene, designated AvrPi7, in a segregating population consisting of 189 ascospore progenies derived from a cross between field isolates CHL346 and CHL42. In order to determine the chromosomal location of the AvrPi7 locus, a total of 121 simple sequence repeat (SSR) markers were developed based on the whole-genome sequence of reference isolate 70-15 of M. oryzae. Linkage analysis of the locus with these SSR markers showed that eight SSR markers on chromosome 1 were linked to the locus, among which the closest flanking markers MS1-9 and MS1-15 were 3.2 and 16.4 cM from the locus, respectively. For fine mapping, additional PCR-based makers including eight SSR markers and three candidate avirulence gene (CAG) markers were developed in the region flanking both markers. The AvrPi7 locus was genetically delimited within a 1.6-cM region flanked by markers MS1-21 and MS1-22, and co-segregated with the marker CAG2. To construct a physical map of the AvrPi7 locus, molecular markers linked to the Avr gene were mapped on the supercontigs of the ref-erence isolate 70-15 through bioinformation analysis (BIA). Consequently, the AvrPi7 locus was delim-ited to a 75-kb interval flanked by markers MS1-21 and MS1-22 based on the reference sequence. Merodiploids observed in this study are also discussed.     

徐州矿区煤矸石堆放的生态危害及其烧结模数多孔砖的开发

徐州矿区长期堆放的煤矸石对当地大气、土壤、地下水等造成了严重的污染,回填或堆放不当还诱发环境地质灾害。煤矸石化学成分的分析结果显示当地主要矿区煤矸石的化学成分基本符合墙材生产的技术性能指标。新型煤矸石烧结模数多孔砖是徐州矿区煤矸石墙材资源化的重要方式之一,这种煤矸石多孔砖以全煤矸石为原料配方,是以2M为主型砖尺寸的单手持砖系列的模数砖型,具有多排且有序交错排列的矩形条孔,并可在一套便捷高效的生产工艺中生产,开辟了发展新型绿色节能墙材的新途径。     

延长切花菊观赏期的技术措施

从切花菊的繁殖方法、养护管理、采前栽培因素及采后处理、包装、贮运、保鲜等方面对影响切花菊观赏期延长的因素做了全面分析，并指出延长切花菊观赏期应采取的措施。     

a-SiN:H薄膜的对靶溅射沉积及微结构特性研究

采用对靶磁控反应溅射技术以N₂和H₂为反应气体在硅(100)和石英衬底上制备了氢化非晶氮化硅(a-SiN:H)薄膜. 利用台阶仪、原子力显微镜、紫外-可见(UV-VIS)光吸收和傅里叶红外透射光谱(FTIR)对薄膜沉积速率、微观结构及键合特性进行了分析. 结果表明, 利用等离子反应溅射可在较低衬底温度条件下(T_s<250℃)实现低表面粗糙度和高光学透过率的a-SiN:H薄膜制备. 增加衬底温度可使薄膜厚度减小, 薄膜光学带隙Eg提高, 薄膜无序度减小. FTIR分析结果表明, 薄膜主要以Si-N, Si-H和N-H键合结构存在, 随衬底温度增加, 薄膜中的键合氢含量减小, 而整体键密度和Si-N键密度增加. 该微观结构和光学特性的调整可归因衬底温度升高所引起的衬底表面原子迁移率和反应速率的增加.