火电厂水冷渣仓的研究

火力发电厂干排渣系统中,渣仓是系统中不可缺少的存贮设备之一,研究工作采用调查法和分析法相结合的形式,开发了一种新型水冷渣仓,使以往单一存贮功能渣仓,转化成为一个既具有存贮功能,又具有换热功能,贮渣和渣余热回收同步进行,使排渣温度进一步降低,具有节能减排功效,同时也能够给用户带来一定的经济效益。

微波等离子体原子发射光谱仪测定食品中的铝含量

研究了微波消解、干法消解和湿法消解3种前处理方法对微波等离子体原子发射光谱法测定食品中铝含量的影响,检测了定容试剂、定容酸度对测定结果的影响,分析了Pb^(2+)等11种离子对该检测方法铝发射强度的干扰。结果表明:微波消解和湿法消解以硝酸定容较适宜,而干法消解应选择硫酸定容,溶剂的酸度以1%较合适;Pb^(2+)等11种离子对测定结果无干扰。同时,该方法的检出限为0.007 4 mg/L,RSD为1.3%~2.0%,线性范围0.05~1.60 mg/L,微波消解、干法消解和湿法消解的加标回收率分别为96.0%~97.8%、94.9%~95.2%和101.7%~103.4%。这表明微波等离子体原子发射光谱法测定食品中的铝含量是一种简单、便捷、可靠的分析方法。

介孔SiO_2分离富集-火焰原子吸收法测定果汁中痕量铅

研究了介孔SiO_2分离富集-火焰原子吸收法测定果汁中痕量铅的新方法。探讨了溶液pH值、吸附温度、吸附时间、洗脱条件及共存离子对铅分离富集的影响。结果表明:在pH值为7.0、25℃吸附15 min条件下,Pb^(2+)可被介孔定量吸附,其静态饱和吸附容量为9.95 mg/g。吸附在介孔SiO_2上的可用0.05 mol/L EDTA完全洗脱。该方法线性范围0.2~10.0μg/m L,检出限为2.04 ng/m L,相对标准偏差(RSD)为3.4%(n=11,ρ=2.0μg/m L)。加标回收率为95.0%~97.5%。该方法可用于食品果汁样品中痕量铅的测定。

巧克力中沙门氏菌检验能力验证的结果与分析

目的参加由中国食品药品检定研究院负责实施的NIFDC-PT-135巧克力中沙门氏菌检验能力验证活动,提高微生物实验室沙门氏菌的检验检测能力,对实验室进行质量控制。方法按照NIFDC-PT-135《巧克力中沙门氏菌检验作业指导书》和GB4789.10-2016《食品安全国家标准食品微生物学检验沙门氏菌检验》条目要求对3件样品进行检验,利用沙门氏菌生化鉴定盒和API20E生化鉴定试剂条进行鉴定。结果样品编号为CODE:0024的样品未检出沙门氏菌,编号为CODE:0754的样品检出沙门氏菌,编号为CODE:0883的样品未检出沙门氏菌。结论本次实验室的能力验证试验结果为“满意”,通过参加沙门氏菌的能力验证,促进检测技术水平的提升,为以后的工作开展提供技术储备。

Decreased expression of β-nerve growth factor correlated with histological changes in a cryptorchidism rat model

Background Nerve growth factor （NGF） is well-known for its important role in the development and maintenance of the nervous system.Along with its neurotrophic role,NGF has been detected in the testis of mouse,rat and human,suggesting an additional non-neurotrophic effect in the male reproductive system.The expression of β-NGF in the undescended testes （cryptorchidism） has not been detected at present.The aim of this study was to evaluate the expression of β-nerve growth factor mRNA and protein in experimental cryptorchidism.Methods A unilateral mechanical cryptorchidism model in the Sprague-Dawley rat was established and the expression of β-NGF with histologic changes in experimental cryptorchidism were investigated using one step quantitative real-time reverse transcription-polymerase chain reaction,in situ hybridization histochemistry,immunofluorescence and hematoxylin-eosin staining.Results The expression of β-NGF mRNA and protein were both significantly decreased in the development of unmarred testis and cryptorchidism-induced testis,and the decrease of β-NGF in cryptorchidism-induced testis was far greater than that in uninjured testis.Conclusion From this investigation,we confirmed a lower expression of β-NGF in undescended testes than in the development of testis.