Multicriteria analysis of ventilation in summer period

This paper presents a multicriteria analysis of ventilation during summertime in Europe. Multicriteria analysis theories are used to determine the most suitable ventilation strategy on a university building, that is to say to ensure the best possible indoor air quality, thermal comfort of the occupants and the lower energy consumption in case of accelerated diurnal or nocturnal ventilation and/or air conditioning. After defining the possible actions, the criteria of quality regarding thermal comfort, indoor air quality and energy consumption are defined. The possible actions are then assessed relative to each of these three criteria and ranked from the best to the worst ones using two different multicriteria analysis methods.     

梨小食心虫性信息素的简便合成

[目的]以廉价、易得的原料合成梨小食心虫性信息素(Z/E)-12-十四碳烯醇乙酸酯.[结果]以35.9%的总收率合成了梨小食心虫性信息索(Z/E)-12-十四碳烯醇乙酸酯,GC分析结果表明顺反异构体比例为87/13.将所得的顺反异构体混合物在亚硝酸钠和硝酸体系中经构型转化得到顺反比例为23/77的(Z/E)-12-十四碳烯醇乙酸酯,产物结构经IR、1H NMR等方法确证.[结论]该路线简洁且比大多数文献报道的方法产率略高,值得借鉴.     

高效毛细管电泳测定乳制品中的酪蛋白糖巨肽

建立了高效毛细管电泳(HPCE)分离测定乳制品中酪蛋白糖巨肽(CMP)的新方法。研究了影响CMP与杂质峰分离的因素,如分离缓冲溶液的种类、浓度、pH值等。结果表明,CMP校正峰面积与质量浓度在60～4 000 mg/L范围内具有良好线性关系,线性相关系数为0.9993,检出限(S/N=3)为20 mg/L,定量限为60 mg/L。该方法简单快速,适用于添加乳清蛋白粉的各种乳制品中酪蛋白糖巨肽的常规检测。     

Loss of crystal violet binding activity in stationary phase Yersinia enterocolitica following gamma irradiation

Ionizing radiation can eliminate virulent Yersinia enterocolitica from meat. It is possible, however unlikely, that a small number of Y. enterocolitica could survive the pasteurization process. The virulence ofY. enterocolitica is dependent upon the presence of a 70 kb plasmid. The effect of low-dose ionizing radiation on the plasmid-associated virulence trait of crystal violet binding was investigated. Y. enterocolitica strains which carried the virulence plasmid were suspended in Butterfield's Phosphate Buffer or raw ground pork and irradiated to a dose of 1·0 or 1·25 kGy, respectively. Loss of crystal violet binding increased 10-fold following exposure to ionizing radiation, regardless of the suspending medium. Polymerase chain reaction analysis of Y. enterocolitica isolates that did not bind crystal violet following irradiation indicated that loss of the virulence plasmid, as opposed to mutation of a single plasmid-encoded gene, was the major mechanism for elimination of the crystal violet binding trait.     

Modeling effects of gas bubbles on the mechanical behaviors of Ag/Bi-2212 round wires using a double cantilever beam bridge model

Due to the larger current-carrying property, Bi₂Sr₂CaCu₂O_x (Bi2212) superconductors have a great potential application in high field magnet. Bi2212 superconducting material can be fabricated as an isotropic round wire. However, there is 30% void space in the wire, such as gas bubbles. The void space has a larger influence on the property of the wire. In this paper, we will study the effect of gas bubble on the fracture behavior. Based on the double cantilever beam model and critical state theory, the mechanical behavior of Bi2212 wire is studied for decreasing field. Two different damage mechanisms are discussed using the strain energy release rate and strain of bridge. The results show that the large gas bubble can increase the strain of bridge. The central filaments with gas bubble are easier to be damaged than the edge filaments with gas bubble.     

亚洲玉米螟性信息素的简便合成

以廉价的1,12-十二碳二醇为起始原料,经单边溴代、乙酰化、氧化吡啶氧化和Wittig反应,以36.6%的总收率合成了亚洲玉米螟性信息素(Z/E)-12-十四碳烯醇乙酸酯(Z/E,89/11),接着将顺反异构体混合物在亚硝酸钠和硝酸体系中经构型转化得到顺反比例为17/83的12-十四碳烯醇乙酸酯。产物通过红外光谱、核磁共振光谱数据确证,并采用气相色谱确定了顺反异构体的比例。该方法简单、易操作,而且总产率相对高于文献报道。     

内蒙古地区居民蔬菜中农药残留膳食暴露风险评估

目的 了解内蒙古地区蔬菜中农药残留情况,对内蒙古地区蔬菜中农药残留膳食暴露风险进行评估。方法 利用2016—2019年内蒙古地区风险监测的蔬菜中农药残留数据,结合2012年全国总膳食研究中内蒙古地区居民的食品消费量数据,采用食品安全指数法与急性膳食暴露风险评估方法对我区居民通过蔬菜摄入的农药残留进行风险评估。结果 2016—2019年共检测蔬菜样本9类15 106份。蔬菜中有机磷类、有机氯类、氨基甲酸酯类及拟除虫菊酯类农药均有检出,有机磷类农药总体检出率为0.98%（72/7 315）;有机氯类农药总体检出率为3.43%（109/3 178）;拟除虫菊酯类总体检出率为4.44%（56/1 261）;氨基甲酸酯类总体检出率为0.30%（10/3 352）。其中有机磷类农药中超标的有氧化乐果（0.05%,4/7 315）、甲拌磷（0.16%,12/7 315）、毒死蜱（0.10%,7/7 315）、甲基异柳磷（0.01%,1/7 315）、水胺硫磷（0.01%,1/7 315）、灭线磷（0.01%,1/7 315）;有机氯类农药超标的有腐霉利（0.09%,3/3 178）、百菌清（0.03%,1/3 178）;拟除虫菊酯类农药超标的有氯氟氰菊酯（0.32%,4/1 261）;氨基甲酸酯类农药超标的有克百威（0.09%,3/3 352）。通过对内蒙古地区居民蔬菜中农药残留膳食暴露风险进行评估,结果表明,采用食品安全指数法（IFS）以农药残留浓度Ri的平均值进行评估时,IFS均小于1,风险可接受;当以Ri的最大值评估时,我区人群对于蔬菜中甲拌磷、三唑磷、灭线磷、百菌清及氯氟氰菊酯农药残留存在暴露健康风险。急性暴露评估结果表明,当西红柿中甲拌磷浓度为1.42 mg/kg时,存在急性暴露风险。结论 蔬菜中四类农药均有检出,且存在超标现象。采用食品安全指数法（IFS）以农药残留浓度Ri的最大值评估时,我区人群对于蔬菜中甲拌磷、三唑磷、灭线磷、百菌清及氯氟氰菊酯农药残留存在摄入健康风险。急性暴露评估结果表明,通过西红柿摄入甲拌磷存在急性健康风险。建议相关部门加强对农药使用的监管,更好地保障我区居民身体健康。     

内蒙古医科大学新华校区周围市售香肠和 火腿肠中亚硝酸盐含量的测定

目的采用反相高效液相色谱法检测内蒙古医科大学新华校区周围市售香肠和火腿肠中亚硝酸盐含量。方法选择四丁基溴化铵作为离子对试剂,以甲醇-磷酸缓冲盐为流动相,样品经La Chrom C_(18)色谱柱分离,采用二极管阵列检测器定量分析亚硝酸盐的含量。对市售香肠和火腿肠随机抽样126份,进行亚硝酸盐含量测定,并对结果进行合格性评价。结果亚硝酸盐在0.10~5.0μg/m L浓度范围内有较好的线性关系,线性相关系数为0.9999,检出限为0.015 mg/L,相对标准差均小于5%,回收率在85.0%~99.8%之间。测得该地区市售带包装火腿肠和散装香肠中亚硝酸盐含量分别为4.92±2.29 mg/kg和8.61±1.76 mg/kg,二者差异极显著(P0.01),但均低于国标限量值。结论该地区亚硝酸盐均在安全范围以内,散装香肠和火腿肠中亚硝酸盐含量高于带包装样品。