New versus old broiler housing technology: Which leads to greater profit?

The method of matching samples was used to compare the costs and returns associated with broiler housing technology using Agricultural Resource Management Survey data for 2006 and 2011. Farms with housing that included tunnel ventilation and evaporative cooling cells (new technology) were compared with farms with housing that did not include this technology (old technology). Gross farm income, total variable expenses, and total fixed expenses were higher for the new technology farms for both years. New technology farms had greater income over variable expenses and net cash farm income in both years.     

农林复合经营对土壤化学性质的影响

本试验选取了拜泉县幼龄云杉纯林土壤、大豆土壤、落叶松—美国红云豆农林复合经营型土壤、杨树—水飞蓟和杨树—板蓝根林药复合经营型土壤等5种土壤类型作为研究对象,研究各种农林复合经营条件对土壤化学性质的影响。研究结果表明:实行农林复合经营对土壤化学性质有显著的影响,并因作物的品种而存在差异。总体来看,只要选择适宜的间作品种,一般对林地的土壤都有良好的改善作用。在本试验选择的3种农林复合经营类型中,杨树—板蓝根效果最好。     

不合格血标本护理相关因素原因分析与对策

目的：结合临床实践经验,探讨临床检验中不合格血液标本的原因并制定相应的整改措施,降低血标本不合格率。方法：选取山东省肿瘤医院普外科2013年6月-12月入院患者的血标本,对不合格血标本进行原因分析,2014年1月-6月针对分析的问题进行改进,计算血标本不合格率。结果：通过分析上半年不合格血标本的原因并实施相应措施,下半年血标本不合格率由0.83%降低到0.54%。结论：根据检验科室筛选的不合格标本分析,规范护理人员操作,缩短物业人员运送标本的时间,避免途中剧烈震动,可以有效降低血标本不合格率。     

皖南稻区褐飞虱怀卵雌成虫数量和前期防控对褐飞虱种群动态的影响

通过褐飞虱怀卵雌成虫不同梯度数量下的田间药效试验,研究了安徽省黄山市徽州区单季中稻田二代褐飞虱怀卵雌成虫数量以及前期防控对后期褐飞虱种群动态的影响。试验结果表明:二代怀卵雌成虫数量(x)决定了后期褐飞虱种群大小(y);前期防控(防控:c=1;不防控:c=0)能够明显压低后期褐飞虱种群大小(y);并可建立广义线性回归模型:log(y)=0.943x-3.191c+0.703xc+7.200。根据该模型可以确定两个临界值:(1)x0.4头/百丛时,需要采取\"压前控后\"策略,即在二、三代低龄若虫高峰期各施药一次,才能有效控制褐飞虱发生危害;(2)x2.4头/百丛时,即使采取\"压前控后\"的策略,褐飞虱仍然会大发生。2006-2014年大田普查数据亦表明当x2.4头/百丛时,三代褐飞虱极易大发生。本研究明确了褐飞虱前期种群数量对后期发生程度的影响,并可依据前期怀卵雌成虫数量采取不同的防控策略,实现科学防控,减少用药。     

机组启动态温度预测模型自适应测试技术

基于机器学习的温度预测模型的预测准确度依赖于故障样本,而发电厂的故障样本较少,不同电厂的故障样本往往不能通用.提出故障样本的自适应生成技术和基于灵敏度的测试技术,即通过自适应生成故障样本,并使用故障样本对已部署的温度预测算法应用效果进行灵敏度测试的方法.首先统计温度测点开关量信号测值的历史数据,然后综合历史统计、温度测...     

环境水样CODcr测定方法中催化剂的改进研究

用MnSO4作催化剂高温消解法测定环境水样CODcr,探讨了催化剂选择及用量、混酸的用量、氯离子对测定结果影响,结果表明：选择50 g·L-1 MnSO4溶液0.20 mL,硫酸/磷酸（5∶1）混酸3.00 mL进行测定,其结果与国标法无显著性差异（P=0.05）,当C1浓度低于500 mg·L-1对测定结果无干扰,无需添加有毒的硫酸汞作掩蔽剂,避免了对环境的二次污染,样品测定结果相对标准偏差RSD≤3.8％（n=5）,加标回收率为96.1％～101.1％.该方法具有操作简单、快速、准确等优点,适用于大批量环境水样COD的测定.     

Determination of pah in soil samples by high-performance thin-layer chromatography (HPTLC)

A thin-layer Chromatographic screening-method is presented for the determination of polycyclic aromatic hydrocarbons (PAH) in soil samples. This screening method is intended for a quick overview of the composition of a contaminant. The developed method of separation is well suited for the semi-quantitative determination of PAH in soil samples, and can be used to identify samples that require further analysis by means of GC or HPLC. The separation of 8 PAH groups with a maximum of 2 PAH (discernible by selective excitation of fluorescence) each is possible. The results of the analysis based on PAH group separation can be regarded as semi-quantitative. The extraction of PAH is effected by means of a solvent mixture consisting of n-hexane-acetone (1:1, v/v). The extraction is aided by ultrasonic treatment. The extract is purified by application to an activated silica gel column (solid-phase extraction). The qualitative analysis can be carried out either by visual observation or by fluorimetric scanning (TLC-Scanner). The characteristic fluorescent colours facilitate a reliable visual identification of PAH. The applicability of the method is shown and a comparison to other analytical methods is carried out. Some of the remarkable features of this method are its user-friendly handling, the low consumption of solvents and the applicability without the necessity for extra equipment.     

Efficacy and safety of transdermal methimazole in the treatment of cats with hyperthyroidism

The objective of this study was to determine whether transdermal methimazole was as safe and effective as oral methimazole for the control of hyperthyroidism in cats. Forty-seven cats with newly diagnosed hyperthyroidism were randomized to receive either transdermal methimazole in pluronic lecithin organogel (PLO; applied to the inner pinna), or oral methimazole (2.5 mg q12h for either route). Cats were evaluated at weeks 0, 2, and 4 with a physical exam, body weight determination, CBC, biochemical panel, urinalysis, measurement of total levothyroxine (T4) concentration, indirect Doppler blood pressure determinaiton, and completion of an owner questionnaire. Data between the 2 groups and over time were compared by nonparametric methods. Forty-four cats followed the protocol (17 oral and 27 transdermal). Significantly more cats treated with oral methimazole had serum T4 concentrations within the reference range after 2 weeks (14 of 16 cats) compared to those treated by the transdermal route (14 of 25; P = .027). This difference was no longer significant by 4 weeks of treatment (9 of 11 for oral versus 14 of 21 for transdermal), possibly because of inadequate numbers evaluated by 4 weeks. Cats treated with oral methimazole had a higher incidence of gastrointestinal (GI) adverse effects (4 of 17 cats) compared to the cats treated with transdermal methimazole (1 of 27; P = .04), but no differences were found between groups in the incidence of neutropenia, hepatotoxicity, or facial excoriations. Although the overall efficacy of transdermal methimazole is not as high as that of oral methimazole at 2 weeks of treatment, it is associated with fewer GI adverse effects compared to the oral route.     

ICP-MS测定无公害农产品土壤样中的铅·镉

[目的]简便快速测定无公害农产品土壤样中铅（Pb）、镉（Cd）的含量。[方法]采用湿法消解样品,在硝酸介质中用电感耦合等离子体质谱仪（ICP-MS）测定Pb、Cd的含量。[结果]在最佳测定条件下,Pb、Cd的质量分数分别在1.70～1000.00mg/kg、0.05～100.00mg/kg范围内呈线性关系。相对标准偏差分别小于3.4%和5.2%。[结论]该法具有简便快速、检出限低等特点,可满足土壤样中Pb、Cd的测定。