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排序方式: 共有208条查询结果,搜索用时 15 毫秒
81.
82.
Shunli?JiEmail author Tengfei?Li Wen?Yang Chang?Shu Duo?Li Yan?Wang Li?DingEmail author 《Mikrochimica acta》2018,185(3):203
A hollow porous molecularly imprinted polymer (HPMIP) is described for use in dispersive solid phase extraction of macrolide antibiotics (MACs). The HPMIP was prepared by using spiramycin as the template, methacrylic acid as the functional monomer, and mesoporous MCM-41 (Mobile Composition of Matter No. 41; with a size of about 100 nm) as a sacrificial support. The sorbent was characterized by Fourier transform infrared spectrometry, transmission electron microscopy, nitrogen adsorption and thermo-gravimetric analysis. Several parameters affecting the extraction efficiency were optimized. The material has a large surface area (359 m2·g?1), and most recognition sites are located on the surface of the HPMIPs. This results in high binding capacity (120 μmol·g?1) and fast binding (20 min) in comparison to either MCM-41-core surface MIPs or solid MIPs. The method was applied to the extraction of the MACs azithromycin, spiramycin, tilmicosin, tylosin, clarithromycin, roxithromycin and josamycin from spiked honey. The recoveries, determined by HPLC-MS/MS, ranged from 88.0% to 117% at the three spiking levels tested (1, 5 and 20 μg·kg?1). Intra-day and inter-day assay precision at three spiking levels are <10.7% (for n?=?6) and 12.6% (n?=?3), respectively. The limits of detection are between 3 and 17 ng·kg?1. This indicates the superiority of the method in selective extraction of macrolides even from complex matrices. 相似文献
83.
Sheng-Hung Wu Chu-Chin Hsieh Chung-Cheng Chiang Jao-Jia Horng Wei-Ping Pan Chi-Min Shu 《Journal of Thermal Analysis and Calorimetry》2012,109(2):945-950
Volatile organic compounds (VOCs) and greenhouse gases are the main factors involved in pollution control and global warming. Various treatment methods involving incineration, adsorption, etc., have been employed to reduce VOCs and greenhouse gases concentration in the operating environment and atmosphere. Activated carbon, zeolite, silica gel, and alumina have been broadly used to adsorb pollutants in various industrial applications. Based on the promising effect of adsorption, we analyzed and identified the thermal phenomena of home-made zeolite using various instruments. The endothermic reaction under 100?°C of home-made zeolite was identified as steam adsorption, which is an important discovery. The optimal adsorption temperatures of home-made zeolite have been determined at 200?C550?°C. 相似文献
84.
C.-C. Chiang J.-C. Lee Y.-M. Chang C.-F. Chuang C.-M. Shu 《Journal of Thermal Analysis and Calorimetry》2009,96(3):759-763
Knowledge of material safety properties is critical for safe handing in the chemical process industries, especially for flammable
chemicals that might result in serious fires and explosions. This study investigated the flammability characteristics of methanol
under working conditions during the process. The targeted fire and explosion properties, like explosion limits (UEL and LEL),
vapor deflagration index (K
g), maximum explosion pressure (P
max), and maximum explosion pressure rise [(dP dt
−1)max], were deliberately obtained via a 20-L-Apparatus in 101 kPa (i.e., 760 mmHg/1 atm), 150 and 200 °C, along with various experimental
arrangements containing nitrogen (N2) or carbon dioxide (CO2) as inert component. Particularly, this study discussed and elucidated the inert influence on the above safety-related parameters
by two different inerting gases of N2 and CO2. The results indicated that adding an inert component to fuel–inert gas mixtures determined the decrease of explosion range
and flammability hazard degree. The results also demonstrated that CO2 possessed higher inerting capability than N2 in this study. 相似文献
85.
Three new phenanthrenes from Monomeria barbata Lindl 总被引:1,自引:0,他引:1
Ming Hui Yang Le Cai Mei Hong Li Xiang Hui Zeng Ya Bin Yang Zhong Tao Ding 《中国化学快报》2010,21(3):325-328
<正>Three new monophenanthrene compounds were isolated from an acetone extract of the tubers of Monomeria barbata Lindl. (Orchidaceae).Using spectroscopic methods,the structures of compounds 1-3 were determined as 1,4,7-trihydroxy-2-methoxy- 9,10-dihydrophenanthrene(1),1-(p-hydroxybenzoyl)-2-methoxy-4,7-dihydroxy-9,10-dihydrophenanthrene(2),1,3,8-tri(p-hydroxybenzyl) -4-methoxy-phenanthrene-4,7-diol(3).These compounds showed cytotoxicities on four tumor cell lines(HepG2, HL-60,Skov-3,A431). 相似文献
86.
87.
气相色谱-三重四极杆串联质谱结合QuEChERS测定三七中有机磷农药残留 总被引:1,自引:0,他引:1
建立了改良的QuEChERS样品前处理法,结合气相色谱-三重四极杆串联质谱(GC-MS/MS)同时测定三七中18种有机磷农药残留的方法。样品经1%乙酸-乙腈提取,改良QuEChERS技术净化,利用GC-MS/MS采取多反应离子监测模式测定,基质匹配校准曲线外标法定量。18种有机磷农药残留在2.5~120.0μg/kg范围内线性良好,相关系数(R2)大于0.99;检出限为0.4~1.5μg/kg,定量限为0.8~2.5μg/kg。在3个加标水平(2.5,8.0,60.0μg/kg)下平均回收率为70.5%~118.9%,相对标准偏差为1.0%~9.8%。 相似文献
88.
Tien-Yuan Lu Chung-Cheng Chiang Sheng-Hung Wu Kuan-Chung Chen Shinn-Jou Lin Chia-Yuan Wen Chi-Min Shu 《Journal of Thermal Analysis and Calorimetry》2013,114(3):1083-1088
In this study, the thermal hazard features of various lithium-ion batteries, such as LiCoO2 and LiFePO4, were assessed properly by calorimetric techniques. Vent sizing package 2 (VSP2), an adiabatic calorimeter, was used to measure the thermal hazards and runaway characteristics of the 18650 lithium-ion batteries under an adiabatic condition. The thermal behaviors of the lithium-ion batteries were obtained at normal and abnormal conditions in this study. The critical parameters for thermal hazardous behavior of lithium-ion batteries were obtained including the exothermic onset temperature (T 0), heat of decomposition (ΔH), maximum temperature (T max), maximum pressure (P max), self-heating rate (dT/dt), and pressure rise rate (dP/dt). Therefore, the result indicates the thermal runaway situation of the lithium-ion battery with different materials and voltages in view the of TNT-equivalent method by VSP2. The hazard gets greater with higher voltage. Without the consideration of other anti-pressure measurements, different voltages involving 3.3, 3.6, 3.7, and 4.2 V are evaluated to 0.11, 0.23, 0.88, and 1.77 g of TNT. Further estimation of thermal runaway reaction and decomposition reaction of lithium-ion battery can also be confirmed by VSP2. It shows that the battery of a fully charged state is more dangerous than that of a storage state. The technique results showed that VSP2 can be used to strictly evaluate thermal runaway reaction and thermal decomposition behaviors of lithium-ion batteries. The loss prevention and thermal hazard assessment are very important for development of electric vehicles as well as other appliances in the future. Therefore, our results could be applied to define important safety indices of lithium-ion batteries for safety concerns. 相似文献
89.
Several nuclear charge radii had been calculated based on the law of A1/3 and isospin dependence Z1/3 formula which had been used to describe the charge radii data. It is achieved that the isospin dependence Z1/3 formula is superior to the generally accepted A1/3 law through mean root square deviation analysis, that is, the Z1/3 formula is more effective to describe the charge radii data. 相似文献
90.