Online measurement of water content in candidate reference materials by acousto-optical tuneable filter near-infrared spectrometry (AOTF-NIR) using pork meat calibrants controlled by Karl Fischer titration

Certified reference materials (CRMs) are prepared from a wide variety of matrices. Water removal is an excellent way of achieving increased matrix lifetime and hence CRM stability. High-speed acousto-optical tuneable filter near-infrared spectrometry (AOTF-NIR) has been implemented for measurement of water content in powder matrix reference materials in amber glass vials. Almost 50,000 spectra were collected from 1300 to 2100 nm with a 2 nm increment for powders of meat, rye grass, potato, cotton seed and sugar beet. The AOTF-NIR instrument was placed in a capping machine, with a measurement frequency of 10–15 vials/min and a trigger signal for reproducible collection of spectra. The calibrants comprised 19 pork meat powder samples equilibrated with different hygrostatic solutions or subjected to oven drying to achieve different water concentrations. Mixtures of powders with different water content were also prepared in order to obtain a calibration range from 0.5 to 8.3% water (m/m). All calibration samples were measured by volumetric Karl Fischer titration (V-KFT), accredited under ISO 17025. The calibrants were then measured by AOTF-NIR together with the samples. Multiplicative scatter correction (MSC) was applied to the absorbance spectra in order to correct for the scattering of light in the different powders and scattering effects from the vials. A partial least squares regression model (PLS) based on two principal components was created and applied for prediction of water content in the samples with a standard error of 0.5% water (m/m).     

我国竖炉球团生产技术进步

阐述了的几年我国在竖炉球团生产方面取得的新进展，包括竖炉 生产工艺的改进。     

Antimicrobial properties of grape seed extracts and their effectiveness after incorporation into pea starch films

Chemical analysis and antimicrobial nature of grape seed extracts (GSE) and their Reisling Vitis vinifera L. application as fortificants for edible starch films were investigated. GSE possessed an antioxidant activity of 17.18 ± 1.29 mmol TROLOX equivalents g_extract⁻¹ and total phenolic content of 327.58 ± 7.24 mmol gallic acid equivalents g_extract⁻¹ mainly attributed to their flavonoid and phenolic acid composition determined by high-performance liquid chromatography accomplished to a diode array detector and a electrospray ionisation mass spectrometer in negative mode (HPLC-DAD/ESI-MS). GSE inhibited the growth of Gram-positive food-borne pathogens while Gram-negatives were not inhibited. After GSE were incorporated into pea starch films, thickness of enriched films increased and the puncture and tensile strength decreased compared to control films. Furthermore, migration of phenolic compounds from the films to different food simulants, aqueous, acidic and alcoholic solution was determined according to 89\109\EEC directive. A higher particle migration in acidic simulants was found. Finally, the effect of GSE incorporated pea starch films was tested in vitro with pork loins infected with Brochothrix thermosphacta. GSE films reduced the bacterial growth in 1.3 log colony forming units mL⁻¹ after 4 days incubation at 4 °C.     

Treasure of the Past IX: Exposure Standardization of Iodine-125 Seeds Used for Brachytherapy

A method for calibrating iodine-125 seeds in terms of exposure has been established. The standard free-air ionization chamber, used for measuring soft x rays, was chosen for the measurements. Arrays of four to six seeds were used to enhance the ionization-current-to-background-current ratio. Seeds from an array were measured individually in a re-entrant chamber. The quotient of the exposure rate for the array by the sum of the ionization currents in the re-entrant chamber is the calibration factor for the re-entrant chamber. Calibration factors were established for three types of iodine-125 seeds. The overall uncertainty for the seed exposure calibrations is less than 6%.     

A/O工艺污泥上浮现象实例探讨

分别从pH、DO、COD、水温、内回流比、SRT等方面对污水处理厂沉淀池在高温季节污泥上浮现象进行分析,得出在水温较高时,硝化反应充分,同时由于内回流流量和剩余污泥排放量较小导致沉淀池内反硝化反应加剧,生成大量N2造成污泥上浮,并对此提出了可行的解决措施.     

炼油厂硫酸渣的综合利用研究

采用加热法将炼油厂硫酸渣分离成酸水、油和剩余渣三个部分。酸水和油经过精制处理可直接利用，剩余渣经中和反应生产隔离剂、磺化沥青等产品，以达到对酸渣较完全的综合利用。结果表明：1t酸渣经加热后，可分离酸水约300kg（浓度约70％）、酸性油约150kg、剩余渣约550kg。550kg剩余渣经反应调合可生成隔离剂1t或磺化沥青约1t。     

异丙醇对泥磷制取次磷酸钠的影响研究

以泥磷为原料,异丙醇为分散剂制取次磷酸钠,考察温度、水磷摩尔比、碱磷摩尔比及分散剂的加入量对次磷酸钠得率和反应速率的影响。结果表明,最适宜反应条件为反应温度85℃,水磷摩尔比为110∶1,碱磷摩尔比为3.6∶1,异丙醇加入量为10 mL/20 g泥磷,活性炭加入量为6 g/20 g泥磷。     

复配抗氧化剂在牡丹籽油乳液中的抗氧化作用研究

为提高牡丹籽油乳液的氧化稳定性，将叔丁基对苯二酚（TBHQ）与天然抗氧化剂（生育酚、抗坏血酸）进行复配，测定不同抗氧化剂对牡丹籽油乳液的抗氧化作用，并分析了不同复配抗氧化剂的相互作用机制。结果表明：在贮藏30 d时，添加和未添加抗氧化剂牡丹籽油乳液的粒径相较于0 d 均略有增加，200 mg/kg TBHQ与800 mg/kg抗坏血酸复配时乳液的Zeta电位绝对值最大，且抗氧化作用最强；TBHQ与抗坏血酸表现出较好的协同抗氧化作用，与生育酚表现出拮抗作用；TBHQ与生育酚之间拮抗作用的原因主要是TBHQ减少了生育酚在牡丹籽油乳液中油水界面的含量，而TBHQ与抗坏血酸之间协同作用主要是由于抗坏血酸增加了TBHQ在牡丹籽油乳液中油水界面的含量。综上，TBHQ与抗坏血酸复配能提高牡丹籽油乳液的氧化稳定性。     

影响种分过程主要因素的研究进展

系统介绍了影响晶种分解过程的主要因素以及国内外在这方面的研究成果。