新时代背景下焊接专业全英文课程建设与改革实践——以《Solid State Welding》为例

在全球国际化和国家战略“双一流”建设的背景下,积极构建焊接技术与工程专业或焊接方向的国际化人才培养体系与模式,大力推进全英文课程的建设与改革,加快培养焊接领域国际化综合人才具有十分重要的意义。课程建设与改革是新工科建设的实施途径,文中以《Solid State Welding》全英文课程实践为例,不断完善新工科焊接方向课程体系建设,构建与国际接轨的教学内容与方法,将国际化视野、国际化教学思维及方法融入到全英文教育教学中,使学生在掌握国际课程知识的基础上,开拓国际视野,有效培养国际交流与合作能力。

Applications of Floquet-Magnus and Fer Expansion Approaches during Cross Polarization Radiation in Solid State NMR

This paper investigates the concept of Cross Polarization (CP) experiment in addition to revisiting the two potential expansion schemes recently developed in the field of solid-state nuclear magnetic resonance (SSNMR): namely, the Floquet-Magnus expansion and the Fer expansion. We use the aforementioned expansion schemes for the calculation of effective Hamiltonians and propagators when the spin system undergoes Cross Polarization radiation. CP is the gateway experiment into SSNMR. An in-depth comprehension of the underlying mechanics of spin dynamics during the cross-polarization experiment is pivotal for further experimental developments and optimization of more complex solid-state NMR experiments. The main contribution of this work is a prospect related to spin physics;particularly regarding to generalization of the calculation. This work reports original yet interesting novel ideas and developments that include calculations performed on the CP experiment. In fact, the approach presented could play a major role in the interpretation of several fine NMR experiments in solids, which would in turn provide significant new insights in spin physics. The generality of the work points towards potential applications in problems related in solid-state NMR and theoretical developments of spectroscopy as well as interdisciplinary research areas as long as they include spin dynamics concepts.

STUDIES ON SOLID STATE REACTIONS OF COORDINATION COMPOUNDS(LXⅡ)Solid state synthesis and crystal structure of the complex ICu_(0.84)Au_(0.16)(PPh_3)_2(SC(Ph)NHPh)CIJ·0.5CS_2

[Cu_(0.84)Au_(0.16)(PPh_3)_2(SC(Ph)NHPh)Cl]·0.5CS_2=,Mr=895.79,monoclinic,space group P2_1/a,a=17.231(3),b=14.611(2),c=18.000(3) ,β=105.56(2)°,V=4365(1) ~3, Z=4,D_c=1.37g/cm^3.,λ(MoK_α)=0.71073 ,μ=12.15cm^(-1),F(000)=1855,R=0.052, R_W=0.045 for 3930 observed reflections with Ⅰ>1.5σ(Ⅰ).The central metal atom has a dis. torted tetrahedral geometry with bond lengths Cu-S=2.384(2) (Au-S=2.389(4)), Cu-Cl=2.481(3)(Au-Cl=2.474(1))and Cu-P=2.269(2)-2.289(2)(Au-P=2.270(4)-2.279(4)) .

Solid state fermentation of rapeseed cake with Aspergillus niger for degrading glucosinolates and upgrading nutritional value

Background： Rapeseed cake is a good source of protein for animal feed but its utilization is limited due to the presence of anti-nutritional substances, such as glucosinolates （GIs）, phytic acid, tannins etc. In the present study, a solid state fermentation （SSF） using Aspergillus niger was carried out with the purpose of degrading glucosinolates and improving the nutritional quality of rapeseed cake （RSC）. The effects of medium composition and incubation conditions on the GIs content in fermented rapeseed cake （FRSC） were investigated, and chemical composition and amino acid in vitro digestibility of RSC substrate fermented under optimal conditions were determined. Results： After 72 h of incubation at 34℃, a 76.89% decrease in GIs of RSC was obtained in solid medium containing 70% RSC, 30% wheat bran at optimal moisture content 60% （w/w）. Compared to unfermented RSC, trichloroacetic acid soluble protein （TCA-SP）, crude protein and ether extract contents of the FRSC were increased （P〈 0.05） 103.71, 23.02 and 23.54%, respectively. As expected, the contents of NDF and phytic acid declined （P〈 0.05） by 9.12 and 44.60%, respectively. Total amino acids （TAA） and essential amino acids （EAA） contents as well as AA in vitro digestibility of FRSC were improved significantly （P 〈 0.05）. Moreover, the enzyme activity of endoglucanase, xylanase, acid protease and phytase were increased （P 〈 0.05） during SSF. Conclusions： Our results indicate that the solid state fermentation offers an effective approach to improving the quality of proteins sources such as rapeseed cake.

Utilization of winery wastes for Trichoderma viride biocontrol agent production by solid state fermentation

Biocontrol agents are safe and environmental friendly alternatives for pesticides in agriculture application. Trichoderma viride WEBL0703 performed a high level of antagonistic activity toward a broad spectrum of phytopathogens and was determined as a biocontrol agent, which was produced by solid state fermentation using grape marc and wine lees. The maximum yield of T. viride conidia was up to 6.65 × 10^9 CFU/g initial dry substrate （IDS） after 10 d fermentation. As important enzymes for protecting plants from disease, chitinase, β-glucanase, and pectinase yields were 47.8 U/g IDS, 8.32 U/g IDS and 9.83 U/g IDS, respectively. These results show that it is feasible to convert winery wastes to a value-added and environmental friendly biocontrol agent.

Solid state interfacial reactions in electrodeposited Ni/Sn couples

Ni/Sn couples, prepared by sequentially electroplating Ni layers and Sn layers on metallized Si wafers, were employed to study the microstructures and growth kinetics of Ni-Sn intermediate phases, when the Ni/Sn couples were aged at room temperature or armealed at temperatures from 150 to 225℃ for various times. The results show that the NiSn phase and Ni3Sn4 phase are formed, respectively, in the aged couples and annealed couples. The Ni3Sn4 layer is continuously distributed between the Ni and Sn sides in the annealed Ni/Sn couples. The Ni3Sn4 growth follows parabolic growth kinetics with an apparent activation energy of 39.0 kJ/mol.

Paddy Husk as Support for Solid State Fermentation to Produce Xylanase from Bacillus pumilus

To optimize culture conditions for xylanase production by solid state fermentation （SSF） using Bacillus pumilus, with paddy husk as support, solid medium contained 200 g of paddy husk with 800 mL of liquid fermentation medium [xylan, 20.0 g/L; peptone, 2.0 g/L; yeast extract, 2.5 g/L; K2HPO4, 2.5 g/L; KH2PO4, 1.0 g/L; NaCl, 0.1 g/L; （NH4）2SO4, 2.0 g/L, CaCl2-2H2O, 0.005 g/L; MgCl2.6H2O, 0.005 g/L; and FeCI3, 0.005 g/L] at pH 9.0 was applied. The highest xylanase activity （142.0 ±0.47 U/g DM] was obtained on the 6th day at 30℃ The optimized paddy husk to liquid fermentation medium ratio was 2：9, and the optimized culture temperature was 40℃. When commercial Birchwood xylan was replaced with different concentrations of corncob, xylanase production was maximized （224.2 U/g DM） in the medium with 150 g/L corncob. Xylanase production was increased by sucrose, fructose and arabinose, whereas reduced by glucose, galactose, lactose and amylose. When organic nitrogen sources were replaced with locally available nitrogen sources such as groundnut powder or sesame seedcake powder or coconut seedcake powder or soy meal powder, the highest xylanase production （290.7 U/g DM） was obtained in the medium with soy meal powder and 16.0 g/L of soy meal powder was the optimum （326.5±0.34 U/g DM）. Based on the optimization studies, B. pumilus produced 2.3 times higher xylanase activity. The medium cost was reduced from 2 458.3 to 178.3 SLR/kg and the total activity which could be obtained from 1 kg of the medium was increased from 48 624 to 220 253 Units.

A Dye-sensitized Nanocrystalline Solid State Photovoltaic Cell

A new type of dye-sensitized nanocrystalline solid state photovoltaic cell based on the wide band gap n-TiO2/p-CuI heterojunction was fabricated. Tetra-carboxyphenyl porphyrine (TPP-(COOH)(4)), squarylium cyanine derivative (SQ-(CH2),(SO3Py+)-Py-.) and ruthenium bipyridyl complex (RuL2(NCS)(2)) were used as photosensitizers. Larger photocurrents and photovoltages were shown in the cell sensitized by ruthenium bipyridyl complex and can be further increased by intercalation of a TiO2 thin underlayer.

SUPERPLASTICITY AND SOLID STATE BONDING OF TITANIUM ALLOYS

Experimental results related to solid state weldability of superplastic titanium alloys are presented. A correlation between superplastic flow and enhanced solid state weldability was established. It has been experimentally shown that a drop in the lower superplastic flow temperature with decreasing mean grain size provides an opportunity to decrease the temperature at whicmethods for titanium alloys.

Solid State Reaction Yielding a Mineral Utilizing Silica Obtained from an Agricultural Waste

Wollastonite, a mineral of wide industrial applications was synthesised from rice husk ash silica and limestone. A number of raw batches consisting of these starting materials, in 1:1 molar ratio, were heat treated to produce it through solid state reaction from 900℃ to 1300℃. The conducted reaction was monitored by XRD step by step. Amount of Wollastonite formed at every temperature was also studied to some extent. Analyses of the obtained data indicated that the target mineral formation was quite effective and almost proportional to a rise in temperature up to 1200℃. The results from both, XRD and chemical analysis were found in fair agreement with one another

An Efficient Solid State Method for Deoximation under Mild Conditions

Oximes of ketones and aldehydes are efficiently converted to the corresponding carbonyl compounds, using a combination of NaHSO4.H20 and paraformaldehyde in good to excellent yields under solid state conditions at room temperature for 10 minutes.

Reaction mechanisms for 0.5Li_2MnO_3 ·0.5LiMn_(0.5)Ni_(0.5)O_2 precursor prepared by low-heating solid state reaction

Lithium-excess manganese layered oxides, which are commonly described in chemical formula 0.5Li2MnO3·0.5LiMn0.5Ni0.5O2, were prepared by low-heating solid state reaction. The reaction mechanisms of synthesizing precursors, the decomposition mechanism, and intermediate materials in calcination were investigated by means of Fourier transform infrared spectroscopy （FT-IR）, X-ray diffraction （XRD）, field emission scanning electron microscopy （FESEM）, thermogravimetric analysis （TGA）, and differential scanning calorimetry （DSC）. The major diffraction patterns of 0.5Li2MnO3·0.5LiMn0.5Ni0.5O2 powder calcinated at 720℃ for 15 h are indexed to the hexagonal structure with a space group of R3m, and the clear splits of doublets at （006）/（102） and （108）/（110） indicate that the sample adopts a well-layered structure. FESEM images show that the size of the agglomerated particles of the sample ranges from 100 to 300 nm.

Use of Solid State Carbothermic Reduction in Production of Transition Metals and Their Carbides

The use of solid state carbothermic reduction as a precursor to the smelting of transition metal ores was examined . The advantages of the introduction of a prereduction stage include enabling the more efficient use of fines and the achievement of higher energy efficiencies. A solid state reduction using carbon as the reductant offers a simpler alternative for their treatment. Subsequent treatment of the reduced material could include intensive bath smelting to produce ferroalloys or, in some case, solid state separation of the transition metal carbide where this has commercial significance.

Synthesis of Mesoporous Chromium Aluminophosphate (CrAlPO) via Solid State Reaction at Low Temperature

Mesoporous chromium aluminophosphate （CrAIPO） was successfully synthesized via solid state reaction （SSR） route at low temperature in the presence of a cationic surfactant cetyltrimethyl ammonium bromide （CTAB） and inorganic sources such as A1C13 · 6H20, CrCI3 · 6H20 and NaH2PO4 · 2H20. Characterizations by means of powder X-ray diffraction （XRD）, N2 adsorption- desorption, high resolution transmission electron microscopy （HR-TEM）, scanning electron micrography （SEM）, energy dispersion spectroscopy （EDS）, thermo-gravimetry （TG）, Fourier transform infrared spectroscopy （FT-IR）, and ultraviolet visible light spectroscopy （UV-Vis） were carried out to understand both the pore characteristics and electron transition route of these obtained materials. The experimental results show that the meso-CrA1PO materials with various Cr/A1 molar ratios possess a mesostructure and a specific surface area of 193 to 310 m2/g corresponding to an average pore size of 5.5 to 2.2 rim, respectively. The maxium content of Cr in meso-CrA1PO materials synthesized via SSR route can achieve 16.7wt%, being significantly higher than that of the meso-CrA1PO prepared via a conventional sol-gel route. Meanwhile, the formation mechanism of the meso-CrA1PO was also proposed.

Lithium-ion transport in inorganic solid state electrolyte

An overview of ion transport in lithium-ion inorganic solid state electrolytes is presented, aimed at exploring and de signing better electrolyte materials. Ionic conductivity is one of the most important indices of the performance of inorganic solid state electrolytes. The general definition of solid state electrolytes is presented in terms of their role in a working cell （to convey ions while isolate electrons）, and the history of solid electrolyte development is briefly summarized. Ways of using the available theoretical models and experimental methods to characterize lithium-ion transport in solid state elec- trolytes are systematically introduced. Then the various factors that affect ionic conductivity are itemized, including mainly structural disorder, composite materials and interface effects between a solid electrolyte and an electrode. Finally, strategies for future material systems, for synthesis and characterization methods, and for theory and calculation are proposed, aiming to help accelerate the design and development of new solid electrolytes.

Salt-assisted Low Temperature Solid State Synthesis of High Surface Area CoFe_2O_4 Nanoparticles

A novel salt-assisted low temperature solid state method using CoCl2.6H2O, FeCl3.6H2O and NaOH as precursor and using NaCI as a dispersant to synthesize high surface area CoFe2O4 nanoparticles, has been investigated. The effects of the molar ratio of added salt and calcination temperature on the characteristics of the products were investigated by X-ray diffraction （XRD）, transmission electron microscopy （TEM）, vibrating sample magnetometer （VSM） and Brunauer, Emmett and Teller （BET） surface area analysis. Results showed that the introduction of leachable inert inorganic salt as a hard agglomeration inhibitor in the mixture precursor led to the formation of high dispersive CoFe2O4 nanoparticles; and the increase in specific surface area from 28.28 to 73.97 m^2/g, and the saturation magnetization is 84.6 emu/g.

Isothermal grain growth of reactive spray formed 7075 alloys in semi-solid state

The grain growth behavior in reactive spray formed 7075+2.91 vol percent TiCAl alloy was studied and compared with that of spray formed 7075 Al alloy at semi-solid state. Theeffects of in-situ TiC particles on the microstructure of spray formed 7075 Al alloy were alsoinvestigated. The specimens were heat-treated isothermally at various temperatures between thesolidus and liquidus of 7075 Al alloy for times in the range of 10-60 min, then quenched in water.The microstructure of reheated specimens was characterized using scanning electron microscopy andoptical microscopy. The grain size was measured using a mean linear intercept method. Results showthat the in-situ TiC particles can effectively retard grain growth and refine the grain at a limitedsize. The grain growth exponent in Arrhenius equation increases from 2 to 3, which indicates thatthe in-situ TiC particles have the significant pinning effect on grain coarsening in the semi-solidstate.

THE SOLID STATE ALDOL CONDENSATION REACTION OF ACETYLFERROCENE AND AROMATIC ALDEHYDES

The aldol condensation reactions of acetylferrocene with several aromatic aldehydes have been studied in the solid state.The results showed that they revealed different reactivities in the solid slate from that in solution and eight compounds have been prepared. Their structures have been characterized by UV,IR,1~HNMR,HS and elemental analysis.

Synthesis of Lanthanide β-Diketonates by Solid State Reaction at Low Heating Temperature

Solid state reactions between β diketones (HPMBP, HDBM) and LnAc 3· x H 2O(La,Nd: x =3/2;Tb: x =4) have been investigated at low heating temperature. Pure compounds of Ln(PMBP) 3 and Ln(DBM) 3 are obtained by solid state reaction, and characterized by elemental analysis, infrared radiation (IR),X ray diffraction (XRD) and photoacoustic spectra. The solid state reaction properties of β diketones and their influences on the structures of products are discussed.

Chemical Kinetic Aspects of Solid State Reaction Producing Wollastonite from Rice Husk Silica and Limestone

An industrial mineral wollastonite (CaSiO3) was produced under solid state conditions from rice husk silica and limestone. Reaction was carried out at 900’C to 1300’C for 1 h. The product batches were subjected to XRD and chemical analysis techniques specific for wollastonite. Mole fractions of different product batches were calculated on the basis of accumulated data to study the kinetics. Specific rate constants and reaction rate were also found out. Various probable models of mechanism for reaction were considered and testified with the laid down criterion for suggesting the suitable one. The resulting data were treated with Arrhenius equation as well and activation energy was calculated--therefrom. In addition to finding it’s value from the slope of Arrhenius curve, an alternate method was also applied for this purpose. Both of the values were observed to be comparable. The activation energy required for performed reaction was found to be almost one third of that reported for synthesizing CaSiO3 by using quartz. This referred to the economical preparation of wollastonite by using rice husk as a source of silica instead of quartz.