检索结果-南通市图书馆

A simulation study of airborne wear particles from laboratory wheel-rail contacts

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

particuology 2016年第5期14卷 31-42页

作者： Hailong Liu Lage Tord Ingemar jonsson par Goran jonsson KTH-Royal Institute of Technology Division of Applied Process Metallurgy Department of Materials Science and Engineering SE-100 44 StockholmSweden FOI SWedish Defence Research Agency Division of CBRN De fence and Security 5E-901 82 Umed Sweden

Laboratory measurements of airborne particles from sliding contacts are often performed using a tri- bometer located in a ventilation chamber. Although knowledge of particle transport behavior inside the chamber is required because it can influence the analysis of measurements, this knowledge is lacking. A numerical model was built based on the same geometry as a pin-on-disc measurement system to explain particle transport behavior inside the chamber and to determine the deviation between real amounts of generated and measured particles at the outlet. The effect of controlled flow conditions on the airflow pattern and particle transport inside the chamber was studied for different experimental conditions. Cal- culations show that a complex airflow pattern is formed by the spinning disc, and that it differs for each rotational speed. Simulation results reveal that particle transport in the chamber is governed mainly by the airflow pattern. The deposition velocity in the chamber was estimated and the possibility that part of the generated particles would remain in the chamber was studied. This led to an approximate estima- tion of particle loss rate. A comparison between experimental and simulated results with respect to the particle mass flow rate close to the outlet yields a reference factor of 0.7, which provides an indication of the difference between measured and real values.

关键词： Airborne particles particle transport Concentration particle loss rate Deposition velocity

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

西欧国家猪的育种改良方法(续)

国外畜牧学(猪与禽) 1982年第1期 1-5页

作者： p.jonsson 许振英

杂交作为从遗传上提高生产的工具 Lush除了在动物育种科学其他方面的贡献外,还在二十年代末开始通过实验性研究来探讨近交与杂种优势的理论背景。此无疑是接受了***用豚鼠做的近交与杂交工作的启示(Wright,1921,1922;

关键词：畜牧生产父本母本近交农业生产亲本杂交优势杂种优势育种方案后裔鉴定家畜鉴定后裔测定猪育种母猪基因型相关遗传相关遗传参数动物育种杂交体系

在线全文

同方期刊数据库

学校读者我要写书评

暂无评论

西欧国家猪的育种改良方法

国外畜牧学(猪与禽) 1981年 1-5页

作者： p.jonsson 许振英

前言今天理解的动物育种,是以群体遗传为基础的,肇始于孟德尔定律的再发现(1900)和 Hardy 与 Weiberg 发现的在随机配种群体下的基因频率平衡原理(1908)。数量性状遗传的概念,把表型显现区别为遗传组分与环境组分的观点,虽早在1903年已... 详细信息

前言今天理解的动物育种,是以群体遗传为基础的,肇始于孟德尔定律的再发现(1900)和 Hardy 与 Weiberg 发现的在随机配种群体下的基因频率平衡原理(1908)。数量性状遗传的概念,把表型显现区别为遗传组分与环境组分的观点,虽早在1903年已经 ***-hannsen 树立(他还是'基因'一辞的首创

关键词：后裔测验后备猪子代估值协方差家畜鉴定杂交后代遗传进展量遗传改进量后备公猪选择指数遗传率遗传力核心群背膘厚繁殖群动物育种加性值育种值半同胞超声波扫描仪数量性状产肉性能瘦肉率眼肌面积育种方案

Determining short chain fatty acids in sewage sludge hydrolysate: A comparison of three analytical methods and investigation of sample storage effects

在线全文

同方期刊数据库

学校读者我要写书评

暂无评论

Journal of Environmental Sciences 2014年第4期26卷 926-933页

作者： Victor Ibrahim Tobias Hey Karin jonsson VA SYD SE-201 21 Malmo Sweden Water and Environmental Engineering Department of Chemical Engineering Lund University SE-21100 Lund Sweden

In anaerobic digestion, the production of short-chain fatty acids （SCFAs） can be beneficial or harmful to the overall process, depending on the concentration of accumulated acids. Therefore, the accurate determination of the SCFA concentration in both fresh and stored sludge hydrolysates is important. To select a suitable method for monitoring SCFAs during the anaerobic digestion of sewage sludge, the accuracy of three available analytical methods, including 5 pH point acid titration （TITRA5）, gas chromatography （GC）, and spectrophotometry, were compared in the present study. The results revealed that TITRA5 and GC displayed better agreement in the achieved measurements and higher precision and accuracy than the spectrophotometric assay, as supported by the application of different statistical models. TITRA5 excelled in titrating unfiltered hydrolysate while simultaneously measuring the alkalinity, whereas the GC method provided detailed information on the contribution of different fatty acids to the total acidity. In contrast, the spectrophotometric assay suffered from many forms of interference, depending on the sample＇s matrix. SCFA production followed the pattern of enzymatic reactions and fitted the Michaelis-Menten model. In addition to promoting TITRA5 as an accurate and robust analytical tool for routine SCFA analyses, this comparative study also demonstrated the possibility of storing hydrolysate samples at different temperatures and durations without altering the SCFA measurements.

关键词： five pH point titration gas chromatography spectrophotometry short-chain fatty acids sludge hydrolysis sample storage

维普期刊数据库

The effects of temperature and resource availability on denitrification and relative N_(2)O production in boreal lake sediments

在线全文

学校读者我要写书评

暂无评论

Journal of Environmental Sciences 2016年第9期28卷 82-90页

作者： Maria Myrstener Anders jonsson Ann-Kristin Bergstrom Department of Ecology and Environmental Science Umea University90187 UmeaSweden

Anthropogenic environmental stressors（like atmospheric deposition,land use change,and climate warming） are predicted to increase inorganic nitrogen and organic carbon loading to northern boreal lakes,with potential consequences for denitrification in ***,our ability to predict effects of these changes is currently limited as northern boreal lakes have been largely neglected in denitrification *** aim of this study was therefore to assess how maximum potential denitrification and N_2O production rates,and the relationship between the two（relative N_2O production）,is controlled by availability of nitrate（NO_3^-）,carbon（C）,phosphorus（p）,and *** were performed using the acetylene inhibition technique on sediments from a small,nutrient poor boreal lake in northern Sweden in *** potential denitrification and N_2O production rates at 4°C were reached already at NO_3^-additions of 106–120 μg NO_3^-–N/L,and remained unchanged with higher NO_3 *** incubation temperatures increased maximum potential denitrification and N_2O production rates,and Q10 was somewhat higher for N_2O production（1.77） than for denitrification（1.69）.The relative N_2O production ranged between 13% and 64%,and was not related to NO_3^-concentration,but the ratio increased when incubations were amended with C and p（from a median of 16% to 27%）.Combined,our results suggests that unproductive northern boreal lakes currently have low potential for denitrification but are susceptible to small changes in NO_3 loading especially if these are accompanied by enhanced C and p availability,likely promoting higher N_2O production relative to N_2.

关键词： Acetylene NO3 Carbon DOC Nitrous oxide ratio Sediment

维普期刊数据库

让生活用纸工厂走进生活圈未来生活用纸工厂将以与社会互利共生存的方式运行

在线全文

学校读者我要写书评

暂无评论

中华纸业 2015年第14期36卷 10-15页

作者： Ulf jonsson Bjrn magnus

像其他的公司一样，维美德正在研究开发那种能够使用较少的能源、水和原材料以及最小化环境冲击和废弃物但获得具有更高效率的技术。近年来，通过利用维美德能源效率创新的充分潜能，我们已经使生活用纸生产线的能耗降低了30%。目前，... 详细信息

像其他的公司一样，维美德正在研究开发那种能够使用较少的能源、水和原材料以及最小化环境冲击和废弃物但获得具有更高效率的技术。近年来，通过利用维美德能源效率创新的充分潜能，我们已经使生活用纸生产线的能耗降低了30%。目前，我们能够降低生产线各个部分能源的用量，同时还可以回收、转换以及将这些能源返回到生产过程中去。

关键词：生活用纸互利共生生活圈工厂能源效率运行社会研究开发

维普期刊数据库

Combined nasal CpAp(nCpAp)and inhaled nitric oxide(iNO)for moderate RDS of the newborn: effects from 30-min exposure

在线全文

学校读者我要写书评

暂无评论

Acta pharmacologica Sinica 2003年第12期 171-172页

作者： R LINDWALL,E BERGGREN,M BLENNOW,M FLANBY,C FROSTELL,B jonsson,p-A LONNQVIST,M NORMAN,M SVENSSON Department of Anesthesia and Intensive Care Karolinska Institutet Danderyd Hospital Stockholm Sweden Department of Anesthesia and Intensive Care Karolinska Institutet Danderyd Hospital Stockholm Sweden Department of Anesthesia and Intensive Care Karolinska Institutet Danderyd Hospital Stockholm Sweden Department of Anesthesia and Intensive Care Karolinska Institutet Danderyd Hospital Stockholm Sweden Department of Anesthesia and Intensive Care Karolinska Institutet Danderyd Hospital Stockholm Sweden Department of Anesthesia and Intensive Care Karolinska Institutet Danderyd Hospital Stockholm Sweden Department of Anesthesia and Intensive Care Karolinska Institutet Danderyd Hospital Stockholm Sweden Department of Anesthesia and Intensive Care Karolinska Institutet Danderyd Hospital Stockholm Sweden Department of Anesthesia and Intensive Care Karolinska Institutet Danderyd Hospital Stockholm Sweden

Treatment with iNO has so far mainly been described and approved for delivery during endotracheal intubation and mechanical ventilation. We have recently validated a modified nasal CpAp(nCpAp) svstem for the concomita... 详细信息

关键词： Combined nasal CpAp effects from 30-min exposure iNO)for moderate RDS of the newborn nCpAp)and inhaled nitric oxide from for of RDS

Irritable bowel syndrome: physicians' awareness and patients' experience

在线全文

同方期刊数据库

学校读者我要写书评

暂无评论

World Journal of Gastroenterology 2012年第28期18卷 3715-3720页

作者： Linda Bjork Olafsdottir Hallgrímur Gudjonsson Heidur Hrund Jonsdottir Jon Steinar jonsson Einar Bjornsson Bjarni Thjodleifsson Department of Gastroenterology Landspitali Faculty of Medicine University of Iceland Hringbraut 101 Reykjavik Iceland The Social Science Research Institute University of Iceland Saemundargotu 2 101 Reykjavik Iceland Gardabaer Health Centre Gardatorgi 7 210 Gardabae Iceland

AIM: To study if and how physicians use the irritable bowel syndrome (IBS) diagnostic criteria and to assess treatment strategies in IBS patients. METHODS: A questionnaire was sent to 191 physicians regarding IBS criteria, diagnostic methods and treatment. Furthermore, 94 patients who were diagnosed with IBS underwent telephone interview. RESULTS: A total of 80/191 (41.9%) physicians responded to the survey. Overall, 13 patients were diag-nosed monthly with IBS by specialists in gastroenterology (SGs) and 2.5 patients by general practitioners (Gps). All the SGs knew of the criteria to diagnose IBS, as did 46/70 (65.7%) Gps. Seventy-nine percent used the patient's history, 38% used a physical examination, and 38% exclusion of other diseases to diagnose IBS. Only 18/80 (22.5%) physicians used specific IBS criteria. Of the patients interviewed, 59/94 (62.8%) knew they had experienced IBS. Two out of five patients knew IBS and had seen a physician because of IBS symptoms. Half of those received a diagnosis of IBS. A total of 13% were satisfied with treatment. IBS affected daily activities in 43% of cases. CONCLUSION: Half of the patients with IBS who consulted a physician received a diagnosis. Awareness and knowledge of diagnostic criteria for IBS differ between SGs and Gps.

关键词： Irritable bowel syndrome Questionnaire study Diagnostic criteria Manning criteria Rome criteria physician knowledge

Effects of Additional Rifle-Carriage Training on physiological Markers and Roller-Skiing performance in Well-Trained Biathletes

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

Journal of Science in Sport and Exercise 2021年第3期3卷 292-302页

作者： Malin jonsson Karstrom Kerry McGawley Marko S.Laaksonen Department of Health Science Swedish Winter Sports Research CentreMid Sweden UniversityÖstersundSweden

purpose The purpose was to investigate whether an increased amount of training while carrying the rifle affects skiing in well-trained biathletes at submaximal and maximal workloads during a pre-season period lasting a minimum of 12 *** Seventeen well-trained biathletes(9 females,8 males)were assigned to an intervention(IG,n=10)or control(CG,n=7)***(T1)and after(T2)the training intervention all participants performed,using treadmill roller-skiing,a submaximal test without the rifle on one day and two submaximal workloads and a maximal time trial(TT)with the rifle on a subsequent *** T1 and T2 all participants performed a minimum of 12 weeks of normal training,the only difference between groups being that IG performed more of their training sessions carrying the *** IG performed more training compared to CG(15.4±1.1 vs.11.2±2.6 h/week,pppeed at 4 mmol/L of blood lactate increased significantly for CG from T1 to T2(p=0.028),while only tended to increase for IG(p=0.058).performance during the TT,VO2max and the aerobic metabolic rate increased significantly from T1 to T2,although the differences disappeared when including the speed at baseline as a *** According to the present results,increasing training while carrying the rifle by 2 h/week does not appear to improve skiing performance in well-trained *** addition,physiological markers at submaximal and maximal intensities while carrying the rifle were not affected after the training intervention.

关键词： Anaerobic energy contribution Gross efficiency Lactate threshold Nordic skiing Oxygen uptake Training intervention