氧化时间对纯钛表面微弧氧化膜结构特性的影响

采用微弧氧化技术在纯钛表面制备了含钙磷的多孔复合氧化膜,用扫描电子显微镜、X射线衍射仪、电子探针分析等手段分析了处理时间对氧化膜形貌、厚度、成分、结构的影响。结果表明：随处理时间的延长,膜厚逐渐增大,微孔数量增多、孔径增大、分布趋匀;表面沉积的钙磷盐逐渐减少并消失,膜中钙磷摩尔比趋于稳定;膜中金红石相TiO2增多、锐钛...     

厌氧消化技术在日本有机废水和废弃物处理中的应用

日本污泥厌氧消化始于1932年,目前污泥厌氧消化工程已超过300个,消化池总容积达210×10<'4>m<'3>.目前,全日本共有300多座升流式厌氧污泥床反应器(upflow anaerobic sludgebed,UASB)和膨胀颗粒污泥床(expanded granular sludge bed,EGSB)处理厂,主要用于包括啤酒废水、软饮料废水、酿酒废水、食品加工废水和化工废水在内的高浓度有机工业废水的处理.总结了厌氧消化技术在日本有机废水和有机废弃物处理中的应用状况,以及运行参数.此外,对日本厌氧消化技术在厌氧膜生物反应器、产氢产甲烷两段发酵和沼气生物脱硫等方面的新进展也进行了介绍.     

A Method to Predict the Minimum Fluidization Velocity of Binary Mixtures Based on Particle Packing Properties

An approach was made to predict the minimum fluidization velocity for binary mixtures of spherical particles differing in size and/or density. The spherical multiparticle model proposed by Panigrahi and Murty was employed to describe the relationship between the bed pressure drop and the gas velocity; the voidage at minimum fluidization was estimated by the Westman equation, which was originally used to calculate the packing voidage of mixtures. The predictions agree fairly well with the reported experimental data in the range of Re = 0.12 ? 156, covering both the regions of laminar flow and intermediate flow.     

Deamidation and Functional Properties of Food Proteins by the Treatment with Immobilized Chymotrypsin at Alkaline pH

Ovalbumin, lysozyme, 7S globulin, 11S globulin, and gluten were treated with immobilized chymotrypsin on controlled-pore glass at pH 10 at 20°C to improve their functional properties. Optimum pH of deamidation of ovalbumin by immobilized chymotrypsin was 10, where proteolysis was very limited. Deamidation percentages of ovalbumin, lysozyme, 7S globulin, 11S globulin, and gluten were 10.0, 8.4, 6.0, 5.0, and 8.0, respectively. SDS polyacrylamide gel electrophoretic patterns of ovalbumin and lysozyme showed no difference between untreated and treated proteins, while those of soy proteins and gluten showd that larger molecular weight fractions were dissociated into smaller molecular size fractions. Solubility of gluten was greatly improved at all pHs, 2-12. Both emulsifying and foaming properties of proteins were improved by treatment with immobilized chymotrypsin.     

Demonstration of Loss‐reduction Effect of the Amorphous Cores for Larger‐Capacity Transformers by Trial Manufacture

For the demonstration of feasibility and loss‐reduction effect of the larger‐capacity amorphous core transformers (AMT), this paper proposed the support structure and design method of the iron‐loss reduced amorphous wound cores with a weight of 7 tons. We designed and manufactured 10 MVA single‐phase test model with the cores inserted in a support cage having structures of the stress‐buffered core support, the proof electromagnetic force from the windings, and the stray loss‐reducing shields. The 50%‐loaded total loss of the test model estimated from the calculated and measured results has been reduced by 35% compared with a conventional silicon‐steel core transformer (SST) with the same power capacity.     

Fatigue of shot peened 7075-T7351 SENB specimen – A 3-D analysis

As‐received or shot peened 7075‐T7351 single‐edged notch bend (SENB) specimens, 8.1‐mm thick, were fatigued at a constant maximum load and at stress ratios of R= 0.1 and 0.8 to predetermined numbers of fatigue cycles or to failure. The SENB specimens were then fractured by overload and the tunnelling crack profiles were recorded. The crack‐growth rate, da/dN, after crack initiation at the notch was determined by crack‐profile measurement and fractography at various fatigue cycles. The shot peened surface topography and roughness was also evaluated by three‐dimensional (3‐D) laser scanning microscopy. Residual stresses in the as‐received specimens and those generated by shot peening at Almen scales of 0.004A, 0.008A, 0.012A and 0.016A, were measured by an X‐ray diffraction stress analyser with an X‐ray target, CrK, every 0.1 mm to a depth of 1 mm. The 3‐D stress intensity factor of the curved crack front was determined by the superposition of the 3‐D finite element solutions of the stress intensity factor of the loaded SENB specimen without the residual stress and the stress intensity factor of the unloaded SENB specimen with a prescribed residual stress distribution. da/dN versus the resultant stress intensity factor amplitude, ΔK_I, plots showed that while the residual stress locally retarded the crack‐growth rate it had no effect on the overall crack‐propagation rate.     

Depth Profile Measurement by Secondary Ion Mass Spectrometry for Determining the Tracer Diffusivity of Oxygen in Rutile

Secondary ion mass spectrumètry has been applied for measuring the tracer diffusivity of oxygen in the c direction of single-crystal rutile for a temperature range of 1150 to 1450 K at 6000 Pa pressure of oxygen gas. Specimens diffusion-annealed in oxygen gas containing ¹⁸O were subsequently continuously sputtered and analyzed for ¹⁶O and ¹⁸O. The tracer diffusivity was determined from the depth profile of ¹⁸O, taking into account a surface exchange reaction of oxygen. The tracer diffusivity in Cr₂O³-doped rutile was 3 to 8 times larger than that in pure rutile. For pure rutile, the diffusivity is expressed by D (m²/s)=3.4×10⁻⁷, exp [-251(kJ/mol)/ RT ], and for 0.08 mol% Cr₂O³-doped rutile, by D (m²/s)= 2.0×10⁻⁸ exp[-204(KJ/mol)/ RT ]. The Cr₂O³ doping had a catalytic effect on the rate constant of the surface exchange reaction on the c surface. The rate constant is represented, for pure rutile, by K (m/s)= 2.4×10⁻¹ exp[-246(KJ/mol)/ RT ], and for 0.08 mol% Cr₂O³-doped rutile, k (m/s)= 3.5×10⁻⁵ exp[-131(KJ/mol)/ RT ].     

Evaluation of D（d,n）^3 He reaction neutron source models for BNCT irradiation system design

A mathematical method was developed to calculatc the yield.energy spectrum and angular distribution of neutrons from D(d,n)3 He(D-D)reaction in a thick deuterium-titanium target for incident deuterons in energies lower than 1.0MeV.The data of energy spectrum and angular distribution wefe applied to set up the neutron source model for the beam-shaping-assembly(BSA)design of Boron-Neutron-Capture-Therapy(BNCT)using MCNP-4C code.Three cases of D-D neutron source corresponding to incident deuteron energy of 1000.400 and 150 kaV were investigated.The neutron beam characteristics were compared with the model of a 2.45 MeV mono-energetic and isotropic neutron source using an example BSA designed for BNCT irradiation.The results show significant differences in the neutron beam characteristics,particularly the fast neutron component and fast neutron dose in air,between the non-isotropic neutron source model and the 2.5 MeV mono-energetic and isotropic neutron source model.     

Determination of Polycyclic Aromatic Hydrocarbons in F-15J,C-130H,and F-4EJ Aircraft Exhaust

There are occupational health concerns at Japan Air Self-Defense Force bases in regard to the exposure of military flightline personnel to carcinogens in aircraft emissions, such as polycyclic aromatic hydrocarbons (PAHs). To characterize the PAHs in military aircraft emissions from different types of engines, aerosol and gas samples were separately collected downwind from aircraft with a turboprop engine (C-130H), turbojet (F-4EJ), and turbofan (F-15J). The gas-phase PAHs were determined by gas chromatography coupled to mass spectrometry and the aerosol-phase PAHs were determined by high-performance liquid chromatography with fluorescence detection. The F-4EJ engine was a source of naphthalene vapor and aerosol PAHs, including carcinogens such as chrysene, benzo (b) fluoranthene, benzo (k) fluoranthene, benzo (a) pyrene, dibenzo (a,h) anthracene, benzo (ghi) perylene, and indeno (1,2,3-cd) pyrene. These heavier (five and six-ring) PAHs were also included in the emissions from the F-15J with its newer, high-temperature F-100 turbofan engine, but the concentrations were approximately one-tenth of those in the F-4EJ. In contrast to these fighter aircraft, the C-130H was found to be a significant aerosol source of the lighter, three-ring (phenanthrene and anthracene) and four-ring (fluoranthene and pyrene) PAHs, but not the heavier ones. These results demonstrate that various aircraft are sources of PAHs in the military flightline environment.     

和线画匹配的阶调再现

目的为了探索和线画匹配的阶调再现。方法采用明暗描画的非真实感渲染方法将阶调再现这个反映输入明暗和打印出图像的浓度关系的画质因素导入到面积变调的线画中。结果建立了一套自动绘制线画的系统,并发现了和线画匹配的阶调再现。结论可以看出要表现深层的感受,即使是灰度值数值段很少的明暗阶调,选择合适的阶调再现也是非常重要的。