滚道磨削中手轮轮廓偏置功能的应用

本文以"咸阳机床厂"生产的内滚道磨床"XYJ-2017"和英国"MATRIX CHURCHILL"公司生产的4703外滚道磨床为例,论述了内、外滚道磨削加工进程中手轮轮廓偏置功能的具体应用。     

Chemical characterization and properties of five deep-sea fish species

Some important flesh properties were determined for the deep-sea species Portuguese dogfish (Centroscymnus coelolepis), leafscale gulper shark (Centrophorus squamosus), black dogfish (Centroscyllium fabricii), roughhead grenadier (Macrourus berglax), and mora/deepsea cod (Mora moro).Chemical composition, water holding capacity, cook loss and shelf-life, as indicated by bacterial counts, were determined. For some of the species investigated, variations could be observed between fish caught in spring and fish caught in summer. The fish used in this study were caught at Hatton Bank in the North Atlantic, where fishing takes place mainly from April to September.     

Retention of folates in cooked,stored and reheated peas,broccoli and potatoes for use in modern large-scale service systems

This study aimed to evaluate retention of folate in vegetables caused by different processes used in modern large-scale service systems and the food industry. The concentration of folates present in raw samples of peas, broccoli and potatoes was measured during different cooking methods, warm and cold holding and reheating. The main folate forms in vegetables, tetrahydrofolates and 5-methyltetrahydrofolates, were analysed using a validated high-performance liquid chromatography (HPLC) method.     

Red Cell Microparticles Suppress Hematoma Growth Following Intracerebral Hemorrhage in Chronic Nicotine-Exposed Rats

Spontaneous intracerebral hemorrhage (sICH) is a disabling stroke sub-type, and tobacco use is a prominent risk factor for sICH. We showed that chronic nicotine exposure enhances bleeding post-sICH. Reduction of hematoma growth is a promising effective therapy for sICH in smoking subjects. Red-blood-cell-derived microparticles (RMPs) are hemostatic agents that limit hematoma expansion following sICH in naïve rats. Considering the importance of testing the efficacy of experimental drugs in animal models with a risk factor for a disease, we tested RMP efficacy and the therapeutic time window in limiting hematoma growth post-sICH in rats exposed to nicotine. Young rats were chronically treated with nicotine using osmotic pumps. sICH was induced in rats using an injection of collagenase in the right striatum. Vehicle/RMPs were administered intravenously. Hematoma volume and neurological impairment were quantified ≈24 h after sICH. Hematoma volumes in male and female nicotine-exposed rats that were treated with RMPs at 2 h post-sICH were significantly lower by 26 and 31% when compared to their respective control groups. RMP therapy was able to limit hematoma volume when administered up to 4.5 h post-sICH in animals of both sexes. Therefore, RMPs may limit hematoma growth in sICH patients exposed to tobacco use.     

Diversity in metabolite production by Fusarium langsethiae, Fusarium poae, and Fusarium sporotrichioides

The production of mycotoxins and other metabolites by 109 strains of Fusarium langsethiae, Fusarium poae, Fusarium sporotrichioides, and F. kyushuense was investigated independently in four laboratories by liquid or gas chromatography analyses of cultural extracts with UV diode array, electron capture, or mass spectrometric detection systems. From the compiled results, it was found that F. langsethiae consistently produced the trichothecenes diacetoxyscirpenol (DAS), T-2 toxin (T-2), HT-2 toxin (HT-2), and neosolaniol (NEO) and, to a lesser extent, some additional trichothecene derivatives. F. langsethiae also produced culmorins, chrysogine (CHRYS), aurofusarin (AUF), and enniatin (EN). F. sporotrichioides showed a metabolite profile similar to that of F. langsethiae, while F. poae had a different profile as 41 of 49 strains produced nivalenol (NIV) and other 8-keto trichothecenes, in addition to DAS and derivatives of this metabolite. Only a trace amount of NIV was detected from one strain of F. kyushuense. In summary, all the three core taxa of this joint study were found to produce trichothecenes. Fusarin C (F-C) was not detected from F. langsethiae, but it was produced by F. poae and F. sporotrichioides. Aurofusarin was only detected from a few strains of F. langsethiae, while nearly all strains of F. poae and F. sporotrichioides produced this compound. In contrast, chrysogine was not detected from F. poae, but was produced by the other two taxa. Production of enniatins was scattered among the three main taxa of this study, whereas beauvericin (BEA) was produced by many strains of F. poae and F. sporotrichioides. Only one odd strain of F. langsethiae (IBT 9959) produced beauvericin. However, the status of this strain is uncertain. By a polyphasic approach using species-specific metabolite profiles, the fruity odour of F. poae, and morphological observations, it was concluded that F. langsethiae, F. poae, and F. sporotrichioides should be regarded as three significant taxa at a species level.     

基于微尺度的列车制动金属镶嵌行为研究

列车制动过程中,无论是踏面制动还是盘式制动都存在金属镶嵌现象,造成车轮踏面与制动盘盘面损伤,从而对车辆运行带来安全隐患.为研究金属镶嵌的形成原因及行为,选取低摩擦因数合成闸瓦与车轮、粉末冶金闸片与制动盘两种摩擦副产生的金属镶嵌物,进行宏观与微观形貌观察、材料物理及力学性能试验和材质成分含量分析.采用有限元软件ABAQU...     

Enterotoxin formation by Clostridium perfringens during sporulation and vegetative growth

Growth, sporulation and enterotoxin production have been followed for three different strains of Clostridium perfringens on a vegetative (FTG) medium and a sporulation (DS) medium. Enterotoxin production was followed by use of enzyme-linked immunosorbent assay (ELISA). All strains produced enterotoxin under both vegetative growth and sporulation in spite of the fact that one strain is known to be enterotoxin negative. The presumed negative strain produced about the same amount of enterotoxin on both media (1 ng/ml). The two other strains produced about 1000–2000 times more enterotoxin during sporulation than during vegetative growth.     

Database Correlation Method with Error Correction for Emergency Location

The constantly growing number of mobile terminal users increases also the number of mobile originated emergency calls. In the United States mobile terminal location in case of an emergency call was mandated with stringent accuracy requirements by Federal Communications Commission (FCC) in 1996. Since July 2003 emergency call location is required also in the European Union (EU), but contrary to the US, without accuracy limits. The global positioning system (GPS) offers high location accuracy, but the density of GPS-capable terminals is very low. Thus, to be able to provide location estimations for all mobile originated emergency calls nationwide, techniques based on cellular network are preferred. In many cases, however, conventional techniques cannot provide sufficient accuracy. This is typical especially for urban areas, where obstacles in signal propagation path degrade location estimation. In urban areas the mobile terminal user density is high and a substantial part of urban emergency calls are mobile originated requiring accurate location estimation. In this paper, we propose a method for emergency call location in urban areas. This database correlation method (DCM) is complemented by error correction method (ECM) developed in the frame of the EU IST project cellular network optimization based on mobile location (CELLO) [http://www.telecom.ntua.gr/cello/]. In performance evaluations DCM has proven to offer sufficient urban accuracy of 44 m in GSM field trial and 25 m in UMTS simulations. The ECM has been tested and proven to ease the implementation of DCM.     

Scores vs. stars: A regression discontinuity study of online consumer reviews

With the rising popularity of consumer reviews, the design of the review system becomes increasingly crucial for e-commerce platforms and online retailers in their business decision-makings. Though the relationship between consumer reviews and sales has been extensively studied, only few studies have been conducted on the effects of different review designs. In this paper, we collect detailed review data from Meituan.com, a popular Chinese shopping website, to examine the effects of numerical presentation of consumer reviews (detailed to one decimal place) and graphical presentation of consumer reviews (in half-stars) on sales. By using a regression discontinuity design, we find that while consumer review scores may affect sales positively, the star presentation can create negative, rather than positive, jumps at cutoffs. Consumers restrict their attention to a star category; therefore, the “best” sellers in a lower star category are better off than the “worst” sellers in a higher star category. The incentive for review manipulation is strongly reduced, which in the long run will create trust and confidence for the review system as well as the sellers. For those sellers that are just below the cutoffs, simply crossing over the cutoffs would not lead to higher sales. Instead, they will have to substantially improve their service quality to attract consumers.