Computed tomographic evaluation of gas hole formation and structural quality in Gouda‐type cheese

Computed tomography (CT) was performed on Gouda‐type cheese during ripening to evaluate gas hole formation and structural quality. The cheese was exposed to different ripening conditions, including variations in ripening temperature and concentration of butyric acid bacteria. Computed tomography images were obtained every 2 weeks for 16 weeks to assess the volume, shape and location of gas holes. The results demonstrate that CT makes the nondestructive monitoring of cheese gas hole formation and evaluation of the structural features of cheese possible throughout the ripening period.     

Microflora, Sensory and Exudate Changes of Vacuum- or Nitrogen-Packed Veal Chucks Under Different Storage Conditions

Apart from increases in microflora number at —4°C under vacuum and at 0°C under nitrogen, there was in general no significant (P gt; 0.05) differences in numbers of lactobacilli, psychrotrophs, aerobes and anaerobes between vacuum- and nitrogen-packed veals during 49 days of storage at 3 and 7°C, regardless of dark and lighted displays. The initial psychrotrophs consisted primarily of Pseudomonas putida (> 72%) but by day 49 Lactobacillus spp. comprised at least 64% of the total in both atmospheres. Sensory and exudate data showed a highly significant (P < 0.05) difference due to the effect of storage time and temperature above 0°C. Nitrogen-packed veals exhibited a lower incidence of greening and exudate loss at 0, 3 and 7°C. Light generally had important effects on off-odor and exudate loss, irrespective of package types.     

Control of H2O generated during the CO2 hardening process in a casting mold

An additive reagent was introduced into a water glass binder system for enhancing the mechanical properties and dimension stability of a casting mold, and for improving the surface quality of a cast product. Two different processes with three different additive reagents were employed to investigate the relation between fracture strength of the mold and water (H₂O) existed in the mold. In processes I and II, the mold samples were coated with a water glass binder, and then dipped into different solutions with additive reagent after and before carbon dioxide (CO₂) hardening, respectively. The fracture strength of the mold was enhanced by reducing H₂O content in the mold, achieved by a hydrolysis reaction of additive reagents. In process I, the H₂O movement was restricted in the mold by the solid phase, converted from the water glass during CO₂ hardening. When employing process II, especially in the TEOS used as additive reagent, the fracture strength was significantly increased due to the effective reduction of H₂O content in the mold and the homogeneous generation of glass phase by a sol–gel reaction of the additives.     

AN INVESTIGATION ON THE EFFECT OF MANGANESE SPECIFICATION IN BASIC OPEN HEARTH PROCESS

本文结合生产研究了鞍钢碱性平爐冶炼重轨和无缝等碳素镇静钢的锰制度.研究结果指出:就上述鋼种而言,熔炼过程中的锰制度对钢中氧、硫含量以及轧制的成品質量並没有实际影响,换句话说,并没有必要规定熔池含锰量高於一定水平(>0.15—0.2%Mn).相反地,熔池含锰较高或在熔炼过程中加入锰铁均使降碳速度趋於缓慢,从而延长了熔炼时间.因此,只要高炉铁水中含硫量能够合乎规定,用低锰生铁作原料对炼钢並无害处.通过高爐生产数据分析,说明在鞍钢的操作条件下完全有可能生产含锰低而含硫合乎上述规定的铁水,应该认为用低锰生鉄冶炼重轨和无缝类型的优質鋼是切实可行的.     

Preparation of Ni-coated TiC particles using potential hydrogen (pH) for dispersion into a molten metal

Titanium carbide (TiC) particles have been coated with nickel (Ni) particles to increase compatibility between the TiC particles and the metal matrix based on Ni, leading to the improvement in the dispersion of TiC particles into a molten matrix, as functions of the potential hydrogen (pH) of TiC suspension, and the heat-treatment condition. The TiC particles were dispersed into the aqueous solution with various pH values, and then nickel nitrate (Ni(NO₃)₂) as a Ni precursor was added at the TiC suspension. As the pH is increased the content of Ni phase on the surface of TiC particle is increased, due to the increment of attractive force between the TiC particle and the Ni ion by the augmentation of negative value on the surface of TiC particle. The Ni-coated TiC particles heat treated at 500 °C under H₂ atmosphere indicate the TiC and Ni phases only, whereas those heat treated at 1000 °C under Ar atmosphere show a titanium oxide (TiO₂) with the TiC and Ni phases, which is resulted from the oxidation of TiC particle by oxygen contained in Ar gas. The dispersibility of TiC particles into a molten metal would be improved through the coating of Ni particles (or phase), inducing the improvement and reliability of mechanical properties.     

感知风险对大学生网购服装满意度的影响

针对网购感知风险对大学生网购服装满意度影响关系,通过文献分析将网购感知风险要因划分为经济风险、性能风险、社会心理风险、隐私风险和时间风险5个下位要因,同时将满意度要因划分为产品满意度和使用满意度,在此基础上设定研究假设模型、编制问卷并展开调研.SPSS信度检验表明,感知风险的信度为0.812～0.898,满意度的信度为0.859～0.871.SPSS因子探索性分析结果表明:性能风险对感知风险的贡献率最大,为3.312;产品满足对满意度的贡献率最大,为2.232.AMOS验证表明:经济风险对产品满足的路径系数为0.22,关系显著;性能风险对满意度路径系数分别为0.68、0.81,关系显著;时间风险对满意度路径系数分别为0.20、0.51,关系显著;隐私风险对满意度路径系数分别为0.25、0.19,关系显著;其他假设关系不显著.研究结果可以为服装网购商城运营者提供顾客管理、产品构成和营销战略等参考.     

Variable step-size affine projection algorithm based on global speech absence probability for adaptive feedbackcancellation简

A novel approach is proposed for improving adaptive feedback cancellation using a variable step-size affine projection algorithm（VSS-APA） based on global speech absence probability（GSAP）.The variable step-size of the proposed VSS-APA is adjusted according to the GSAP of the current frame.The weight vector of the adaptive filter is updated by the probability of the speech absence.The performance measure of acoustic feedback cancellation is evaluated using normalized misalignment.Experimental results demonstrate that the proposed approach has better performance than the normalized least mean square（NLMS） and the constant step-size affine projection algorithms.     

Powder preparation for a shell mold using a new coating process

A new coating process in the powder preparation for a shell mold has been developed to increase the fracture strength of the shell mold. It is due to the homogeneous formation of a glass phase on the starting particles and the increase in the glassification efficiency by the reduction in the loss of inorganic precursors. The inorganic binder system used for the new coating process is composed of tetraethyl orthosilicate (TEOS) and sodium methoxide (NaOMe) as the silica (SiO₂) and sodium oxide (Na₂O) precursors, respectively. Three different coating processes are employed for the powder preparation with a high glassification efficiency. In process I, the starting particles are coated with NaOMe, and then TEOS are coated on the particles treated with NaOMe. Process II is the reverse sequence of process I. Process III involves coating of the particles with a mixture of TEOS and NaOMe. The particles coated with an individual or mixture precursor were fixed with an organic binder and then heated at 1000 °C for 1 h. Molds prepared through the new coating processes, especially process III, show a higher fracture strength value compared with that of the conventional convert mold process, which may be caused by the increase in the glassification efficiency of the precursors. Powder prepared by process III shows a more uniform coating of the glass phase than those by other processes, resulting from an enhancement in the phase mixing between SiO₂ and NaOH molecules.