七水硫酸镁干燥脱水制取一水硫酸镁实验研究

一水硫酸镁是较七水硫酸镁含硫镁成分高、附加值大、市场前景广阔的重要化工原料及双元素肥料。苦土法生产的一水硫酸镁品质较低,不能满足市场要求。通过比较高温结晶法和干燥脱水法的工艺特点,以及所涉及的多种设备,在掌握相关资料及小试实验数据的基础上,采用盘式干燥机直接干燥七水硫酸镁的方式制取一水硫酸镁。实验结果表明,该种盘式干燥机在温度为160 ℃、搅拌转速为15 r/min情况下的干燥强度（以水计）为4.1 kg/(m²•h)。使用盘式干燥机可以较好地生产出满足品质要求的一水硫酸镁,使用该机单位产品能耗适中,单位产品净收益在合理范围内。     

试剂级一水合硫酸锂的研制

本文研究了以工业碳酸锂为原料,制备试剂级一水合硫酸锂的工艺条件。     

Quantitative X-Ray Diffraction Determination of α-Lactose Monohydrate and β-Lactose in Chocolate

ABSTRACT:  Lactose is a constituent of milk chocolate. During processing and cooling, lactose may precipitate as α-lactose monohydrate and β-lactose. The presence of α-lactose monohydrate has a deleterious effect on the quality of milk chocolate. A quantitative X-ray diffraction method for determination of α-lactose monohydrate and β-lactose in chocolate is described. The α-lactose monohydrate signal at 19.9°2θ with Cu-Kα X-rays is a cubic function of concentration. The β-lactose signal at 20.9°2θ is a linear function of concentration. α-Lactose monohydrate is detectible at about 0.1 weight% and can be quantified at >0.5 weight%. β-Lactose is detectible at about 1 weight% and can be quantified at >3 weight%. About 10 min is required to prepare and run a sample.
Practical Application: The crystalline form of lactose affects the quality of chocolate. A rapid method for quantifying crystalline forms of lactose in chocolate is described. The method can be used for quality control and for improving chocolate quality.     

Trace-level sensing of creatine in real sample using a zwitterionic molecularly imprinted polymer brush grafted to sol-gel modified graphite electrode

Zwitterionic molecularly imprinted polymeric chains were tethered to the sol-gel modified graphite electrode in brush pattern of high density, for the quantitative estimation of creatine at trace level, without any cross reactivity, in real samples. The modified electrode was activated by preanodization at + 1.4 V (vs. saturated calomel electrode) for the fast ion-exchange recapture of creatine, under mild basic condition (pH 7.1). The detection limit was as low as 1.3 µg mL^− 1 (signal/noise = 3) employing differential pulse, cathodic stripping technique.     

Creatine loading and resting skeletal muscle phosphocreatine flux: a saturation-transfer NMR study

³¹P saturation-transfer nuclear magnetic resonance spectroscopy was used to study skeletal muscle phosphocreatine (PCr) flux in healthy male volunteers. Data analysis included consideration of effects from incomplete saturation and radiofrequency spillover. Spectra were recorded from the resting gastrocnemius muscle before and after 6 days of creatine monohydrate (Cr·H₂O) intake (20 g/day). Parallel to an improved muscle performance during maximal intermittent exercise following Cr·H₂O supplementation, the concentration of PCr increased(P = 0.01) by 23% (34.9 ± 2.8 mmol/ 1 vs. 28.6 + 2.7 mmol/1), whereas other metabolites were unaffected (inorganic phosphate: 4.3± 1.4 mmol/1, free intracellular Mg²⁺: 1.1 ±0.7 mmol 1, cytosolic pH: 7.04 ± 0.02). Forward and reverse fluxes through the creatine kinase (CK) reaction did not change significantly from their baseline levels (v_for: 11.8 ± 5.4 mmol/1 per second vs. 15.3 ± 6.8 mmol 1 per second. (v_rev: 9.5 ± 3.4 mmol/1 per second vs. 10.9 ± 3.7 mmol/ 1 per second). The rate of PCr resynthesis in resting muscle is not limited by the CK reaction, which is near equilibrium. Consequently, the post-load increase in total creatine has no effect on the unidirectional CK reaction rates.     

饲料级一水硫酸锌的离心喷雾干燥研究

以精制硫酸锌溶液为原料，采用离心喷雾干燥方法探索制取饲料级一水硫酸锌的工艺条件，使产品质量符合化工部部颁标准要求。     

Extrusion granulation and high shear granulation of different grades of lactose and highly dosed drugs: a comparative study

Formulations containing different lactose grades, paracetamol, and cimetidine were granulated by extrusion granulation and high shear granulation. Granules were evaluated for yield, friability, and compressibility. Tablets were prepared from those granules and evaluated for tensile strength, friability, disintegration time, and dissolution. The different lactose grades had an important effect on the extrusion granulation process. Particle size and morphology affected powder feeding and power consumption, but had only a minor influence on the granule and tablet properties obtained by extrusion granulation. In contrast, the lactose grades had a major influence on the granule properties obtained by high shear granulation. Addition of polyvinylpyrrolidone (PVP) was required to process pure paracetamol and cimetidine by high shear granulation, whereas it was feasible to granulate these drugs without PVP by extrusion granulation. Granules prepared by extrusion granulation exhibited a higher yield and a lower friability than those produced by high shear granulation. Paracetamol and cimetidine tablets compressed from granules prepared by extrusion granulation showed a higher tensile strength, lower friability, and lower disintegration time than those prepared from granules produced by high shear granulation. Paracetamol tablets obtained via extrusion granulation exhibited faster dissolution than those obtained via high shear granulation. For all lactose grades studied, extrusion granulation resulted in superior granule and tablet properties in comparison with those obtained by high shear granulation. These results indicate that extrusion granulation is more efficient than high shear granulation.     

4,6-二硝基-7-氧-苯并氧化呋咱钾-水合物(KDNP·H2O)的合成、晶体结构与性能

2,4,6-三硝基间苯二酚铅(LTNR)的主要缺点是静电感度过高以及含铅对人体、环境造成危害.为了寻找LTNR的替代物,采用两步法合成了4,6-二硝基-7-氧-苯并氧化呋咱钾-水合物(KDNP·H2O).利用溶剂蒸发法获得了该化合物的单晶.利用元素分析、红外光谱法、核磁共振氢/碳谱法和单晶X-衍射对其结构进行了表征.按国军标GJB-5891测试了其感度,计算了爆热.根据Kamlet-Jacobs方程计算了该化合物的爆轰参数.结果表明,该晶体为三斜晶系,空间群为P-1,有一个结晶水.该起爆药撞击感度为21.3 cm,静电感度为0.69 J,摩擦感度为56％,火焰感度为为24.7 cm,爆热为3.50 kJ·g-1,爆速为6.77 km·s“、爆压为21.25 GPa,显示KDNP·H2O是一种无铅安全环保的起爆药.     

N-乙酰-L-半胱氨酸合成新方法

以乙酸酐为酰化剂一步合成N 乙酰 L 半胱氨酸的新工艺过程 ,获得最佳反应条件为 :乙酸酐与半胱氨酸的物质的量比为 1 30∶1 2 5,酰化试剂分两次加料完成 ;反应温度分段控制 :1 0～ 1 2、35～ 38、55～ 60℃ ;重结晶试剂为乙醇 ;产物收率为 83 1 % ,产品质量分数为 99 3%。