光电倍增管在井下粉尘浓度检测中的应用

基于粉尘粒子的光辐射原理、Mie理论,利用光电倍增管本身的特性,外加电子测量电路对粉尘浓度的检测做了原理性探究.     

浅谈X射线检测在制冷装置壳管式换热器压力容器制造中的应用

制冷装置用壳管式换热器压力容器对接接头是壳体上重要的受控接头，内部缺陷存在超标缺陷会严重影响整个壳体，极端会使整个压力容器报废。制冷装置用壳管式换热器压力容器对接接头的材质都为簿件，在无损检测方法上优先使用射线检测技术。本文通过典型的产品LS1100冷凝器从X射线照相的原理、透照工艺、底片的评定的难点，避免对底片评片的误评、漏评，提高X射线无损检测结果的准确性，保证焊缝质量，使机组正常运转。     

我国上市商业银行高管薪酬影响因素的实证分析

近年来,我国上市金融类公司高管薪酬越来越受到社会各界的广泛关注。利用14家上市商业银行2008年的财务数据,对上市商业银行高管薪酬的各个影响因素进行较全面的分析,通过多元回归模型的建立和实证分析,验证了理论假设,得出各个因素对上市商业银行的影响程度,总结了相关结论和政策建议。     

土壤渗透仪的量值传递及影响量的分析与研究

介绍了土壤渗透仪的工作原理和用途,并建立了土壤渗透仪校准结果的数据模型,分析各不确定度分量主要来源,结合测量实例具体数据,对其合成不确定度进行分析评定,对各不确定度分量进行计算并得出合成不确定度和扩展不确定度,最终可得出该项目的校准测量能力,为我国公路工程质量的安全提供的技术支撑。     

影响动物免疫抗体检测结果的因素分析

对影响动物免疫抗体检测结果的因素进行了分析,并提出了相应的对策。     

共生根瘤菌对NaCl胁迫下紫花苜蓿抗氧化和渗透调节能力的影响

以NaCl胁迫下不同根瘤菌处理的紫花苜蓿为材料,通过测定丙二醛(MDA)、超氧阴离子、超氧化物歧化酶(SOD)、还原型谷胱甘肽(GSH)、脯氨酸、可溶性糖等生理指标,研究共生根瘤菌对紫花苜蓿渗透调节和抗氧化能力的影响。结果表明,接种根瘤菌尤其是接种根瘤菌激活的紫花苜蓿丙二醛含量较低,在处理第15天时根、茎、叶中的含量分别为3.90,0.53,4.16 mmol/g DW,均低于其他2种处理;超氧阴离子含量则在0 ~ 15 d中一直为最低;超氧化物歧化酶活性较高,在处理第15天时最高,根、茎、叶中含量分别为1 592.48,1 317.86,2 068.88 U/g DW·h;还原性谷胱甘肽含量稳定;脯氨酸和可溶性糖含量波动较大,总体呈先增长后下降的趋势。说明接种根瘤菌激活的紫花苜蓿具有较强的抗氧化和渗透调节能力。     

饲料检测在奶牛场精细化管理上的应用

本文从原料品质鉴定、数据库的建立、TMR日粮评价以及饲料的安全控制四方面,概述了饲料检测在奶牛场饲养管理上的应用。     

间接ELISA在猪瘟抗体检测上的应用

间接ELISA以其灵敏、特异、简单、快速、稳定、高通量及易于操作等优点,在猪瘟免疫猪群抗体水平监测、猪瘟的快速诊断与流行病学调查中得到了广泛应用,显示出了良好的应用前景。论文就间接ELISA方法及其在猪瘟诊断上的应用概况做一综述,以期为我国猪瘟的综合防控提供参考。     

Experimental study on the frost characteristics of fin tube heat exchanger

The heat and mass transfer characteristics under frosting on surface of heat exchanger were experimentally investigated in different conditions of air temperature, relative humidity, and face velocity. The heat transfer and heat transfer coefficient decreased faster with the high relative humidity, low air temperature and initial face velocity. The air pressure drop rose faster with the high relative humidity and low air velocity.     

核电厂换热设备涡流检验结果数据统计与分析浅谈

CNPO在核电厂在役检查过程中积累了大量的换热设备涡流检验结果数据,这些数据均以结构化的形式规范存储于专门的核电役检信息化平台(IMS);根据换热设备运行管理、维护的需要, CNPO能够使用这些历史数据进行合适的统计和分析,有效利用这些数据的价值。     

Effect of a heat and moisture exchanger on temperature and humidity of inhaled gas in isoflurane-anesthetized dogs

ObjectiveTo investigate the effects of a heat and moisture exchanger (HME) on the temperature and humidity of inhaled gas in isoflurane-anesthetized dogs.Study designProspective, interventional study.AnimalsA total of four experimental dogs and four client-owned dogs weighing 13.9 ± 7.4 kg (mean ± standard deviation).MethodsThe four experimental dogs were anesthetized on two occasions with and without an intact HME at least 1 week apart. The four client-owned dogs were anesthetized once only for a surgical procedure and assigned to the HME group or no-HME group in alternate order, resulting in six dogs for each group. All dogs were premedicated, anesthetized with propofol and intubated. The HME was connected to the endotracheal tube. Anesthesia was maintained with isoflurane. A digital thermo-hygrometer was placed between the endotracheal tube and HME. The temperature and relative humidity of the inhaled gas were measured every 5 minutes for 60 minutes and the absolute humidity was calculated at each time point.ResultsThe temperature and absolute humidity of the inhaled gas was significantly higher at 5–60 minutes after intubation in the HME group than in the no-HME group. Absolute humidity was maintained above 29 mg H₂O L⁻¹ in the HME group. No significant time-dependent effects on temperature, relative humidity or absolute humidity of the inhaled gas were observed.Conclusions and clinical relevanceThe temperature and absolute humidity of the inhaled gas were higher when an HME was used during isoflurane anesthesia in dogs. The use of an HME may reduce the risk of dehydration and dysfunction of the airway mucosal epithelium.     

Effect of a passive heat and moisture exchanger on esophageal temperature in tumor-bearing dogs during whole-body hyperthermia.

The effect of a passive heat and moisture exchanger on tracheal and large airway temperature, as reflected by esophageal temperature at the thoracic inlet, was determined for 12 anesthetized and ventilated tumor-bearing dogs undergoing whole-body hyperthermia at 42 C. Delivered thermal dose to the esophagus and rectum during 120 minutes of whole-body hyperthermia was quantified as the thermal dose summary measure EQ43. The heat and moisture exchanger significantly increased esophageal EQ43 from 7.3 minutes to 12.1 minutes. Esophageal EQ43, however, remained lower than rectal EQ43. Although use of a heat and moisture exchanger improved esophageal temperature during whole-body hyperthermia, presumably through improved airway temperature, additional methods will be necessary to increase esophageal and airway temperature to the target value of 42 C.     

热应激对家禽性能不良影响的解决方案

正在家禽生产中,热应激(Heat Stress,HS)是全球范围内最为关注的问题之一。热应激会对家禽的生产性能造成负面影响,如降低生长速度、产蛋率和产品安全性等。近最,International Poultry Production杂志就该问题与Muhammad Umar Sohail进行了讨论。     

草地生态系统土壤呼吸及其影响因素研究进展

土壤呼吸在全球碳收支中占有重要的地位,笔者对草地生态系统土壤呼吸在陆地生态系统碳平衡中的作用、土壤呼吸的分类及其影响因素等方面进行了综述。结果表明,草地生态系统土壤呼吸在不同时间空间各组分所占比例不同,生物、非生物及人为活动等因素对草地土壤呼吸影响各异,主要从土壤温度、气候变暖、土壤湿度、降水、干旱化、土壤C/N等非生物因素,叶面积指数、植物光合作用、植被凋落物等生物因素以及人类干扰活动等方面具体阐述这些因素变化对土壤呼吸产生的影响,并对草地土壤呼吸的Q₁₀值及各影响因素间的交互作用进行归纳总结。提出草地生态系统土壤呼吸研究存在的问题和今后重点发展方向,并对未来草地生态系统土壤呼吸的研究工作做了进一步的展望。     

Environmental factors influencing heat stress in feedlot cattle

Data from 3 summer feedlot studies were utilized to determine the environmental factors that influence heat stress in cattle and also to determine wind speed (WSPD; m.s(-1)) and solar radiation (RAD; W.m(-2)) adjustments to the temperature-humidity index (THI). Visual assessments of heat stress, based on panting scores (0 = no panting to 4 = severe panting), were collected from 1400 to 1700. Mean daily WSPD, black globe temperature at 1500, and minimums for nighttime WSPD, nighttime black globe THI, and daily relative humidity were found to have the greatest influence on panting score from 1400 to 1700 (R2 = 0.61). From hourly values for THI, WSPD, and RAD, panting score was determined to equal -7.563 + (0.121 x THI) - (0.241 x WSPD) + (0.00082 x RAD) (R2 = 0.49). Using the ratio of WSPD to THI and RAD to THI (- 1.992 and 0.0068 for WSPD and RAD, respectively), adjustments to the THI were derived for WSPD and RAD. On the basis of these ratios and the average hourly data for 1400 to 1700, the THI, adjusted for WSPD and RAD, equals [4.51 + THI - (1.992 x WSPD) + (0.0068 x RAD)]. Four separate cattle studies, comparable in size, type of cattle, and number of observations to the 3 original studies, were utilized to evaluate the accuracy of the THI equation adjusted for WSPD and RAD, and the relationship between the adjusted THI and panting score. Mean panting score derived from individual observations of black-hided cattle in these 4 studies were 1.22, 0.94, 1.32, and 2.00 vs. the predicted panting scores of 1.15, 1.17, 1.30, and 1.96, respectively. Correlations between THI and panting score in these studies ranged from r = 0.47 to 0.87. Correlations between the adjusted THI and mean panting score ranged from r = 0.64 to 0.80. These adjustments would be most appropriate to use, within a day, to predict THI during the afternoon hours using hourly data or current conditions. In addition to afternoon conditions, nighttime conditions, including minimum WSPD, minimum black globe THI, and minimum THI, were also found to influence heat stress experienced by cattle. Although knowledge of THI alone is beneficial in determining the potential for heat stress, WSPD and RAD adjustments to the THI more accurately assess animal discomfort.     

Review of the impact of heat stress on reproductive performance of sheep

Heat stress significantly impairs reproduction of sheep, and under current climatic conditions is a significant risk to the efficiency of the meat and wool production, with the impact increasing as global temperatures rise. Evidence from field studies and studies conducted using environmental chambers demonstrate the effects of hot temperatures(≥ 32 °C) on components of ewe fertility(oestrus, fertilisation, embryo survival and lambing) are most destructive when experienced from5 d before until 5 d after oestrus. Temperature control ed studies also demonstrate that ram fertility, as measured by rates of fertilisation and embryo survival, is reduced when mating occurs during the period 14 to 50 d post-heating. However, the contribution of the ram to heat induced reductions in flock fertility is difficult to determine accurately. Based primarily on temperature control ed studies, it is clear that sustained exposure to high temperatures(≥ 32 °C) during pregnancy reduces lamb birthweight and wil, therefore, decrease lamb survival under field conditions. It is concluded that both ewe and ram reproduction is affected by relatively modest levels of heat stress(≥ 32 °C) and this is a concern given that a significant proportion of the global sheep population experiences heat stress of this magnitude around mating and during pregnancy.Despite this, strategies to limit the impacts of the climate on the homeothermy, behaviour, resource use and reproduction of extensively grazed sheep are limited, and there is an urgency to improve knowledge and to develop husbandry practices to limit these impacts.