航空声纳ATE测试系统设计

提出了基于ATE技术的航空声纳综合测试系统设计思想,通过对设计系统可行性的总体分析和方案的评估,证明该系统设计方案合理,能够满足测试系统应具备的功能要求并保证原有系统的完整性,从而依据该方案开展航空声纳综合测试系统的下-步研制工作.     

一种高速SiGe BiCMOS 运算跨导放大器的设计

基于SiGe HBT器件良好的频率特性,设计全差分的高速SiGe BiCMOS跨导运算放大器.设计采用TSMC 0.35μm SiGe BiCMOS工艺,利用Cadence Specture进行仿真.结果显示,在3.3V单电源下,功耗20mw,直流开环增益87dB,单位增益带宽2GHz,相位裕度60度,输出摆幅2.4V,输入参考噪声电压4.0nv/√Hz,在1pf的负载电容下,建立时间小于2ns(建立精度0.01%),转换速率1200V/μs.     

OMS-2催化剂成型工艺研究及其在印染废水处理中的应用

以OMS-2粉体催化剂为基础,对催化剂进行挤出成型,考察粘结剂种类、粘结剂用量、润滑剂和孔结构改进剂用量、焙烧温度对成型催化剂机械强度的影响。得到最佳成型工艺条件为,粘结剂硅溶胶用量为OMS-2粉体催化剂质量的105%～110%、辅助粘结剂纳米ZrO_2用量为OMS-2粉体催化剂质量的30%～35%、润滑剂田菁粉用量为OMS-2粉体催化剂质量的2. 5%～3. 0%、孔结构改进剂柠檬酸用量为OMS-2粉体催化剂质量的5%～6%,焙烧温度450℃。成型后催化剂机械强度可达150 N·cm~(-1),满足工业化应用对催化剂强度的要求。将成型催化剂应用于催化湿式氧化印染废水处理,经过432 h活性评价时间,COD平均去除率约91. 6%,反应结束后催化剂结构完整,平均机械强度约144 N·cm~(-1),表现出良好的水热稳定性。     

工业搬迁企业原场地土壤Pb、Cd、Hg、Cr污染研究

针对城市建成区工业企业搬迁原生产场地土壤污染问题,采用单因子指数法、内梅罗指数法和地累积指数法等方法,对原场地土壤中Pb、Cd、Hg和Cr污染程度进行研究。研究结果表明:单因子指数法评价土壤中Cd元素是主要污染因子,属于重污染;Pb元素为中污染;Hg、Cr元素为未污染。内梅罗指数法评价土壤中 Pb、Cd和Hg元素为重度污染,Cr元素为安全;点位1、11和13为重度污染,点位7为中度污染,其他为轻度污染、警戒及安全。地累积指数法评价土壤中Cd元素为偏中污染,Pb元素为轻度污染;Hg和Cr元素为清洁;点位1为中度污染,点位11和点位13为轻度污染,其他点位污染等级为清洁。     

基于神经网络的实物保护系统综合效能评估研究

目前国内外核设施实物保护系统大多采用路径分析法进行有效性评价,通过计算截住概率来衡量系统的优劣,评估指标单一,未能精确反映系统可靠性、指挥策略、信息安全设计等因素对系统性能的影响。为全面分析实物保护系统综合效能,从影响系统效能因素集出发,采用层次分析法(Analytic Hierarchy Process,AHP)建立实物保护系统综合效能评估指标体系,同时借助BP(Back Propagation)神经网络的非线性复合能力,建立核设施实物保护系统综合效能评估模型,完成了海洋核动力平台实物保护系统综合效能评估。评估结果表明:该BP神经网络评估模型收敛迅速,避免了AHP评估过程中不能满足多数样本集中效应的缺点,且具有较好的自适应性、稳定性,为实物保护效能评估领域提供了一种全新思路。     

Physicochemical characteristics,antioxidant capacity and thermodynamic properties of purple-fleshed potatos dried by radio frequency energy

Abstract

The impacts of using radio frequency (RF) energy to dry purple-fleshed potatoes were investigated and compared to infrared radiation (IR) and microwave (MW) drying techniques. The gelatinization rate, color, flavor, morphological, and structural characteristics, thermodynamic properties, as well as antioxidant capacity were examined. The results indicated that the drying time of RF (70?min) and MW (21?min) were shorter than IR (105?min). The gelatinization ratio of MW, RF, and IR were 94.4?±?2.0, 88.3?±?1.4, and 64.5?±?1.1%, respectively. The degree of crystallization of purple-fleshed potato powder decreased with all three drying methods. RF-dried potatoes were able to retain higher polyphenols (loss rate: 4.3%), total anthocyanin (3.7%), and total flavonoid content (35.1%), whereas IR showed the lowest retention. The content of polyphenols also decreased significantly. Furthermore, after RF heating, the scavenging of free radicals was higher compared to MW and IR.     

Instrumental evaluation of defective texture in dry-cured hams

In the first experiment, the effect of the stress relaxation time on texture evaluation of biceps femoris (BF) muscle from dry-cured hams was studied. The specimens were compressed to 25% of their original height and the crosshead speed was 5mm/s. The force decay versus time was recorded and Peleg's model was fitted with different relaxation times. Whatever relaxation time was used, Peleg's model did not describe simultaneously the initial fall of force and the asymptotic tendency of force decay correctly. The initial force and force decay at 2s and at 90s are proposed to assess texture in dry-cured ham. In the second experiment, stress relaxation (SR) and texture profile analysis (TPA) tests were performed on BF and semimembranosus (SM) muscles of 10 hams with abnormal softness and 10 hams with normal texture, at different assay conditions: sample temperature (4°C or 20°C); compression crosshead speed (1mm/s or 10mm/s). The instrumental texture test and the assay conditions that detected defective textures better depended on the muscle considered: for BF muscle the SR test at 4°C and at 1mm/s and for SM muscle the TPA test at 10mm/s at both 4°C or 20°C.     

PRKAG3 and CAST genetic polymorphisms and quality traits of dry-cured hams-II. Associations in French dry-cured ham Jambon de Bayonne and their dependence on salt reduction

This study aimed to evaluate the effects of PRKAG3 Ile199Val and CAST Arg249Lys and CAST Ser638Arg polymorphisms on the quality traits of the French dry-cured ham Jambon de Bayonne and their interaction with salt reduction. Significant (p<0.05) and suggestive associations (p<0.10) between the polymorphisms and several quality traits of dry-cured ham, mainly related to processing and textural properties, were found. PRKAG3 Ile/Val and CAST 249Lys/638Arg presented the highest scores for sensory and processing properties, whatever the salt content.     

某制革企业制革废水处理工程项目设计方案

河北省辛集市某制革企业制革废水处理工程设计规模为600 m~3/d。设计采用以"预处理+多功能池+AO"为主体的工艺,其中多功能池可根据使用需求灵活切换。由2015年1月~6月的运行数据可知,该工艺处理效果较好,运行稳定,实际运行出水水质优于设计值,且可实现污泥减量。并通过对各单元设计的详细介绍及运行数据分析,总结了设计、运行方面的经验。     

Characterization of Longissimus thoracis, Semitendinosus and Masseter muscles and relationships with technological quality in pigs. 2. Composition of muscles

The composition of three porcine muscles (Longissimus thoracis: LT, Semitendinosus: ST, Masseter: MS) was characterized and its link with muscle quality was evaluated. The LT muscle had a higher content of tyrosine, tryptophan, and carbohydrates and a lower content of vitamin E and haem iron than the MS muscle, while the ST had similar composition to MS but a lower content of haem iron. Large differences between muscles were observed in relative amounts of most of the major fatty acids. The LT muscle had higher saturated fatty acids (SFA) and n− 6:n− 3 fatty acid ratio, and lower polyunsaturated fatty acids (PUFA), PUFA:SFA ratio, unsaturation index and average fatty acid chain length than the ST and MS muscles. Muscle pH, redness and chroma were positively correlated with vitamin E and unsaturated lipids and negatively correlated with tyrosine, tryptophan, carbohydrates and saturated lipids, whereas muscle lightness and expressible juice showed similar correlations but an opposite sign with these variables.