人工模拟肠炎沙门氏菌在绿豆芽中的内化定殖能力及其消毒处理研究

本研究以绿豆为作用载体,研究了肠炎沙门氏菌(ATCC13076)在绿豆芽的不同发芽阶段中的内化定殖能力及消除绿豆芽中定殖的肠炎沙门氏菌的有效方法。结果表明:在绿豆发芽前期的4个不同时段(0~48 h内):吸胀期(G_1,0 h)、萌动期(G_2,12h)、发芽初期(G_3,24 h)、发芽期(G_4,48 h),分别接种10~2、10~4、10~6和10~8 CFU/mL的肠炎沙门氏菌时,其在绿豆芽中的内化定殖能力不同。接种浓度为10~2CFU/mL左右时,肠炎沙门氏菌在发芽初期(G_3)和发芽期(G_4)的内化能力较强,另外两个阶段比较微弱。接种浓度不低于10~4CFU/mL时,肠炎沙门氏菌在吸胀期(G_1)的内化能力最强。在吸胀期(G_1)接种10~8CFU/mL的菌液时,最高内化量可达2.6×10~8CFU/g。紫外照射消毒处理对内化定殖的肠炎沙门氏菌有明显的去除效果,而次氯酸钠溶液和硝酸银溶液浸泡处理对内化的肠炎沙门氏菌的去除效果并不明显。     

Potential biomass supply for agro-pellet production from agricultural crop residue in Nepal

Nepal, a country rich in biomass, still does not have any commercial pellet production plants and is wasting large amounts of agricultural crop residue. The current study showed that about 5.61 million tonnes (Mt) of biomass in the form of pellets are potentially available from agricultural crop residues. The brick and cement industries could use these agro-pellets. Co-firing of pellets in such industries could play an important role in reducing the import volume of coal and minimize the related environmental loadings.     

Cyclic properties and ammonia by-product emission of Li/Mg-N-H hydrogen storage material

A magnesium amide-based hydrogen storage material, 3 Mg(NH₂)₂ + 8LiH, was subjected to cycling tests of dehydrogenation and hydrogenation, in which the cyclic trend in the hydrogen storage capacity as well as the amount of the ammonia by-product contained in the desorbed hydrogen gas were recorded. After 300 cycles at 473 K, the initial hydrogen capacity of 4.2 mass% dropped to 3.6 mass%, corresponding to the decay rate of 0.0004 per cycle. The average ammonia concentration through the 300 cycles was determined to be 0.05 ± 0.01 mol%(NH₃/H₂) which is entirely responsible for the hydrogen capacity decay because the ammonia emission leads to the loss of elemental nitrogen from the system. When the dehydrogenation temperature was raised to 573 K, the hydrogen capacity decay became more significant and the ammonia concentration increased to 0.27 ± 0.06 mol%(NH₃/H₂). The reaction kinetics also severely deteriorated during cycling at the higher temperature.     

医院消杀机器人作业安全与交互设计策略

作业安全与设计质量对提高医院公共环境消杀机器人"人机系统"运行效率具有关键作用.以人因工程学、交互科学、认知科学理论为视角,探究医院消杀机器人作业安全与交互设计策略.采用层次任务与表格任务结合H TA-T分析法,构建消杀作业任务流程,剖析作业流程中典型安全事故及其致因逻辑,基于工作域分析法(WDA)对消杀作业约束条件进...     

氧化型锰银矿锰银分离工艺研究

氧化型锰银矿其锰、银分离是处理这类资源的关键工序。试验分别采用煤焙烧、植物副产湿法还原工艺对锰银精矿进行了锰、银分离工艺性能的对比研究。在相同酸消耗情况下,植物副产湿法浸出的锰浸出率接近煤焙烧浸出,而银在浸锰液中溶出率远低于煤焙烧浸出;以玉米秸杆粉还原分离为代表,其浸锰条件选择在L/D=4、n(酸)/n(Mn)=1.76、秸杆/矿粉质量比=0.275、95℃浸出时间4 h时,锰浸出率达97.30%,浸锰渣量少;玉米秸杆粉浸锰渣在NaCN用量5 kg/t渣、常温浸银6 h时,Ag的浸出率为97.77%;并对其它植物副产还原浸出锰性能进行了验证试验。所研究工艺在锰、银分离综合成本方面具有较好的优势。     

蒂森克虏伯钢铁公司的环境实践

德国蒂森克虏伯钢铁公司是世界一流的钢铁企业,也是世界上能源使用效率最高的钢铁企业之一。介绍了其先进的环保理念,并从能源管理、副产品和废料管理、水管理、环境空气保护、应对气候变化挑战几个方面介绍了其环境实践经验。     

高压XLPE绝缘电力电缆若干性能的试验及分析

通过有关试验验证与分析,提出了高压交联聚乙烯(XLPE)绝缘电力电缆的交联均匀性、交联副产物释放和屏蔽层与绝缘交界面光滑圆整性控制及其改善措施。     

核桃加工副产物综合利用途径

随着核桃产业的快速发展,核桃加工副产物的回收利用成为可能。综述了核桃加工副产物的综合利用途径,包括以核桃饼粕为原料制备蛋白粉、核桃乳、浓缩蛋白、分离蛋白、蛋白肽、酱油;以核桃壳为原料制备活性炭,提取棕色素;以核桃青皮为原料制备染色剂、植物农药;以核桃隔膜为原料开发袋泡饮料等。为核桃产业的发展提供参考。     

Efficacy of a high free iodine barrier teat disinfectant for the prevention of naturally occurring new intramammary infections and clinical mastitis in dairy cows

Using a natural exposure trial design, the goal of our study was to evaluate the clinical efficacy of an iodine teat disinfectant with barrier properties and a high level of free iodine relative to a conventional iodine teat disinfectant with no barrier properties and low levels of free iodine. During the 18 wk of the trial, quarter milk samples were collected every 2 wk from 385 dairy cows from 2 herds. Cows on both farms were assigned in a balanced way according to milk yield, number of lactation, days in milk, somatic cell count (SCC) and microbiology culture pretrial into one of following groups: nonbarrier post milking teat disinfectant (NBAR; n = 195 cows; 747 quarters) or barrier postmilking teat disinfectant (BAR; n = 190 cows; 728 quarters). Afterward, at each scoring date every 2 wk, milk SCC was quantified in samples from all mammary quarters and microbiologic culture was only performed on milk samples with SCC >200,000 cells/mL for multiparous cows and SCC >100,000 cells/mL for primiparous cows. A new intramammary infection (NIMI) was defined when a quarter had milk SCC <200,000 cells/mL for multiparous cows and <100,000 cells/mL for primiparous without microorganism isolation, and in a subsequent sampling visit had milk SCC >200,000 cells/mL for multiparous cows and >100,000 cells/mL for primiparous cows, and positive microorganism isolation. A quarter could have several NIMI, but only 1 case per specific pathogen was considered. The most frequently isolated microorganism group on both farms was Streptococcus spp. (6.25% of total mammary quarters), followed by coagulase-negative staphylococci (3.6%) and Corynebacterium spp. (1.5%). In the present study, an interaction occurred between treatment and week of trial on the incidence risk of NIMI. Quarters disinfected with BAR had 54 and 37% lower odds of NIMI than quarters disinfected with NBAR at 8 and 16 wk of the trial, respectively; whereas at other weeks of the study both products had similar incidence risks of NIMI. Overall, teats disinfected with BAR had 46% lower odds of acquiring a clinical mastitis than those disinfected with NBAR. We concluded that the postmilking teat disinfectant with barrier properties and higher free iodine content reduced the risk of clinical mastitis, although differences in new infections were detected at only weekly time points.     

竹笋加工方法研究进展

我国竹资源丰富,竹笋加工方法众多,但竹笋加工技术落后,导致其综合利用率不高,副产物较多,浪费严重。因此,改善竹笋加工工艺、提高竹笋综合利用率、减少副产物浪费对竹笋加工具有重要意义。该文对目前存在的竹笋加工方法、竹笋副产物及其综合利用、竹笋加工过程中存在的问题进行了综述,并展望了竹笋加工的发展趋势。