GC-MS法测定缬草残渣中的化学组分

分别使用95％乙醇和四氯化碳作为提取溶剂,在78℃左右,对已提取过挥发油的缬草残渣中化学成分进行提取,借用气相色谱-质谱联用方法(GC-MS)对提取浸膏中化学组分进行分析.结果显示:以乙醇作为提取溶剂条件下,共鉴定出38中化学组分,数据出峰相对总质量分数为81.7％;以四氯化碳为提取溶剂条件下,共鉴定出44种化学组分,数据出峰相对总质量分数为84.4％.     

A-site Ca2+ substitution induced polyvalent Cu cations and correlated polaron relaxations in colossal permittivity Li1-xCaxCuNb3O9

LiCuNb₃O₉ has been reported newly a colossal permittivity (CP) perovskite, in which the B-site NbO₆ octahedra play a bridging role in the polaron hopping. However, how the A-site modification affects the origin of the polarons and further the CP behaviours remains unexplored. To this end, A-site Ca²⁺ was incorporated to form Li_1-xCa_xCuNb₃O₉, and the local states, dielectric relaxations and conduction behaviours were comprehensively studied. The substitution induces the polyvalent Cu cations, i.e. Cu⁺/Cu²⁺/Cu³⁺. Bond valence sum calculations imply that Cu²⁺ and Cu³⁺ are underbonded, and Cu⁺ is overbonded, while B-site Nb⁵⁺ shows slightly different with theoretical pentavalence. All the compositions exhibit a similarly room-temperature CP response, but present two dielectric relaxations, i.e. T_R1:170–300 K and T_R2:260–400 K. Comprehensive investigations on universal dielectric response and bulk dc conductivity indicate that the T_R1 follows the variable-range-hopping where the electron hopping between the mixed Cu⁺/Cu²⁺, while T_R2 contributes from the Cu³⁺ nearest neighbor hopping.     

Advances in the in vitro digestion and fermentation of polysaccharides

In vitro digestion models are widely used to study the structural changes, digestion and release of food components under simulated gastrointestinal conditions. As compared to the in vivo digestion tests, the in vitro digestion reflects the digestion and utilisation of food after ingestion and has the advantages of being time consuming, inexpensive, reproducible and free from moral and ethical restrictions. This study reviewed the current research studies on the in vitro simulated digestion of polysaccharides conducted in the last 5 years and focused on the oral, gastric and intestinal digestion models, with the aim of providing a basis for the further testing of changes in the content, structure and active ingredients of polysaccharides before and after digestion.     

Pyrometallurgically regenerated LiMn2O4 cathode scrap material and its electrochemical properties

Recycling cathode materials from lithium-ion battery scraps can play a significant role in reducing environmental contamination and resource depletion. In this study, we employed pyrometallurgical techniques to regenerate LiMn₂O₄ cathode materials from recovered cathode scraps. First, the binder was removed under optimal conditions by a heating and stirring method to maximize the dissolution rate of the cathode scrap materials. Next, inductively coupled plasma spectroscopy was used to define the Li and Mn contents, and finally, the LiMn₂O₄ cathode material was regenerated by a pyrometallurgical method. After calcination under the optimum conditions of 500 °C for 12 h, electrochemical performance testing revealed obvious charge and discharge platforms in the charge/discharge curves; further, a high first-cycle discharge capacity was observed at 136.6 mAh·g^-1 (3.0–4.3 V and 0.1 C), which decreased to 93 mAh·g^-1 after 50 cycles. This process is low-cost and environmentally friendly, with the potential for recovering other cathode scrap materials.     

CO2 sensing properties and mechanism of PrFeO3 and NdFeO3 thick film sensor

The CO_2 sensing of PrFeO_3 and NdFeO_3 sensors were investigated. Experimental results show that the resistances for PrFeO_3 and NdFeO_3 in CO_2 gas are larger than those in air and the responses for PrFeO_3and NdFeO_3 sensors increase with an increase in room-temperature relative humidity. When exposed to1000 ppm CO_2, the response of PrFeO_3 thick film based on nano-powders annealed at 700℃can reach8.44 at 160℃for the background of wet air with 58%of room-temperature relative humidity (RH),which is much larger than the corresponding value (3.03) in wet air with 25%RH. The sensing response S of NdFeO_3 thick-film sensor based on nano-powders annealed at 600℃to 3000 ppm CO_2 at the operating temperature 200℃can reach 2.36 for the background of wet air with 72%RH, which is larger than the corresponding value (1.83) in the air with 25%RH. Compared with other CO_2 sensing materials, the PrFeO_3 sensor has larger response at lower operating temperature for CO_2 gas and may be used as a new CO_2 sensing material.     

诺氟沙星片在中国健康受试者空腹和餐后状态下生物等效性研究#br#

目的：采用随机、开放、两周期、自身交叉、单次给药试验设计比较浙江医药股份有限公司新昌制药厂生产的诺氟沙星片与原研产品BACCIDAL在中国健康人体中的生物利用度，并评价两种制剂的生物等效性。方法：分别在空腹和餐后条件下，健康受试者随机交叉单剂量口服诺氟沙星片受试制剂或参比制剂100 mg，采用液相色谱-质谱串联（LC-MS/MS）法测定受试者服药前后不同时间点血浆内药物浓度，采用WinNonlin 7.0软件计算主要药代动力学参数，并评价两种制剂的生物等效性。结果：空腹试验共有28例受试者入组并完成试验，诺氟沙星受试制剂与参比制剂的Cmax分别为（607.62±125.24）ng/mL和（552.01±134.11）ng/mL；AUC0-t分别为（2 551.66±509.08）ng·mL-1·h和（2 429.98±460.47）ng·mL-1·h；AUC0-∞分别为（2 675.40±523.04）ng·mL-1·h和（2 557.68±485.43）ng·mL-1·h；t1/2分别为（6.07±0.69）h和（6.18±0.92）h；两种制剂的Cmax、AUC0-t和AUC0-∞几何均值比的90%置信区间分别为101.45%～121.94%、98.96%～111.27%、98.82%～110.76%。餐后试验共有28例受试者入组并完成试验，诺氟沙星受试制剂与参比制剂的Cmax分别为：（256.54±58.87）ng/mL和（300.80±94.67）ng/mL；AUC0-t分别为（1 314.74±349.92）ng·mL-1·h和（1 278.60±314.77）ng·mL-1·h；AUC0-∞分别为（1 413.73±361.98）ng·mL-1·h和（1 374.98±321.62）ng·mL-1·h；t1/2分别为（6.66±1.23）h和（6.66±1.34）h；两种制剂的Cmax、AUC0-t和AUC0-∞几何均值比的90%置信区间分别为81.42%～93.56%、99.61%～105.58%、99.80%～105.21%。结论：浙江医药股份有限公司新昌制药厂生产的诺氟沙星片与原研产品BACCIDAL在中国健康受试者空腹和餐后服用的状态下等效且安全性良好，临床上可以替换使用。     

多功能橡胶硫化活性剂ZH-73对全钢载重子午线轮胎胎面胶性能的影响

研究多功能橡胶硫化活性剂ZH-73对子午线轮胎胎面胶硫化特性、加工性能、物理性能和动态力学性能等的影响。结果表明:加入2份硫化活性剂ZH-73,混炼胶的门尼焦烧时间略缩短,t90延长,流动性提高,加工性能改善;硫化胶老化前后物理性能相当,60℃的损耗因子明显减小;成品轮胎耐久性能提高,滚动阻力系数降低。     

低浓度挥发性有机物吸附浓缩材料的研究进展

由于挥发性有机物（VOCs）会对环境造成严重的危害，因此VOCs的处理一直备受人们的关注，但发展高效的VOCs处理技术仍然存在严峻的挑战。本文针对大风量、低浓度VOCs的处理展开了综述，重点围绕吸附、催化燃烧处理展开讨论。对于大风量的低浓度VOCs，虽然浓度较低但VOCs排放量非常巨大。通过VOCs浓缩技术，提高浓度减少风量成为降低VOCs处理成本的有效途径。其中，发展高性能VOCs吸附材料是VOCs浓缩技术的关键。阐明了活性炭、分子筛等重要吸附材料的性质及其吸附VOCs的原理，并对吸附材料性质和VOCs种类对吸附效果的影响进行了探讨。展望了活性炭浓缩-催化燃烧技术和分子筛转轮浓缩-催化燃烧技术在大风量的低浓度VOCs处理中的应用前景。     

Synthesis and two-step sintering behavior of solution derived corundum abrasives with plate-like grains

Corundum abrasives with plate-like grains were fabricated by a two-step sintering technique using the solution-based process with the addition of the ternary compound additive Na₃AlF₆-CaO-SiO₂. The two-step sintering method showed obvious advantages over conventional sintering methods in promoting sample densification, suppressing grain growth, and homogenizing the microstructure of the corundum abrasives. The sample doped with 2.5?wt% Na₃AlF₆ and 4?wt% CaO + SiO₂ in the molar ratio of 1:1 possessed a relative density of 99.3%, average grain size of 0.54?µm, and single-particle compressive strength of 49?N. The introduction of seeds reduced the temperature of θ- to α-Al₂O₃ phase transformation. The relationship between the microstructure and the mechanical properties of the abrasives was also discussed.