生乳中钙质量浓度快速检测方法

快速检测法已成为乳品行业的发展趋势,目前生乳中钙质量浓度检测法无相关快速检测法。现开发了一种生乳中钙质量浓度的快速仪器法,其基本原理为:在酸性条件下,样品中钙与偶氮胂Ⅲ作用生成蓝色复合物,通过时间分辨荧光法测定,与经过同样处理的钙校准液进行比较,即可计算出样品中钙质量浓度,其检测范围为0~200 mg/100 mL。

隧道初期支护喷射混凝土阻钙析出配合比试验研究

考虑影响混凝土抗溶蚀性能的四种因素(水灰比、矿物掺和料、减水剂和速凝剂),设计正交试验,利用自制混凝土溶蚀装置模拟了不同配合比下初期支护喷射混凝土溶蚀析钙过程,分析不同配合比对初期支护喷射混凝土抗溶蚀性能、工作性能和力学性能的影响规律。研究结果表明:复掺硅灰、矿渣、速凝剂和减水剂后抗溶蚀性能提升显著,与基准组相比,钙离子质量浓度最大下降45.9%;坍落度过大或过小会使钙离子质量浓度变大,初期支护混凝土坍落度建议控制在10~17 cm;各工况孔隙率变化规律基本相似,掺入硅灰、矿渣、速凝剂和减水剂能有效降低初始孔隙率,提高混凝土初始密实度,但溶蚀作用对混凝土孔隙率没有明显影响;掺入硅灰或矿渣与速凝剂、减水剂的9种工况,初期支护混凝土28 d龄期抗压强度均高于基准组和单掺组,且抗压强度均在30 MPa以上。综合考虑抗溶蚀性能、工作性能和力学性能,建议阻钙析出喷射混凝土水灰比取0.45,矿物掺和料、减水剂和速凝剂的质量比取0.25∶0.011∶0.05。其中矿物掺和料为10%硅灰和15%矿渣。

Influence of surfactants on bioleaching of arsenic-containing gold concentrate

To shorten the bioleaching cycle of arsenic-containing gold concentrate, surfactants were used to promote the interaction between bacteria and ore to increase the arsenic leaching rate. Three different kinds of surfactants were used to evaluate the effects of surfactants on the growth of bacteria and arsenic leaching rate of arsenic-containing gold concentrate. The mechanism underlying surfactant enhancement was also studied. Results show that when relatively low-concentration surfactants are added to the medium, no significant difference is observed in the growth and Fe2+ oxidation ability of the bacteria compared with no surfactant in the medium. However, only the anionic surfactant calcium lignosulfonate and the nonionic surfactant Tween 80 are found to improve the arsenic leaching rates. Their optimum mass concentrations are 30 and 80 mg/L, respectively. At such optimum mass concentrations, the arsenic leaching rates are approximately 13.7% and 9.1% higher than those without the addition of surfactant, respectively. Mechanism research reveals that adding the anionic surfactant calcium lignosulfonate improves the percentage of bacterial adhesion on the mineral surface and decreases the surface tension in the leaching solution.

Effect of Different Calcium Levels on Growth,Yield and Fruit Quality of Tomatoes in Substrate Culture

Tomato seedlings were grown in substrate culture with pots. The formulation of Holland Greenhouse Horticulture Research Institute was used(as CK) and the effects of different Ca concentrations(LCa, CK and HCa)on growth, yield, and fruit quality(protein, Vitamin C, nitrates, organic acid and soluble sugar) of tomato were studied keeping concentrations of other nutrients unchanged in the nutrient solution. The results showed that parameters related to the growth of tomato(plant height and Stem diameter), changes of tomato yield per plant and quality of tomato fruits were the highest when the plants were grown at 20% Ca treatments. In the second study, increased EC concentrations of nutrient solution resulted in stronger plants with improved yields and quality. Four different concentration gradients of nutrient solution treatment were designed based on the results of the first research stage(EC=1.5, 2.5, 3.5, 4.5 m S/cm, respectively). The single tomato plant had the highest production which is 2 268.994 g/plant, when the nutrient solution strength was at EC=1.5 m S cm, whereas they have the best fruit quality when the solution strength at EC 4.5 m S/cm. This suggests the need for wide popularization of the nutrient solution formula in large areas to improve the tomato production.

三元复合驱清垢防垢一体化加药工艺在Z井的应用

针对三元复合驱机采井结垢速度快、易导致机采井结垢卡泵、检泵周期缩短及已有防垢加药工艺无清垢功能的问题,研究了一种清垢、防垢一体化智能加药工艺。通过连续监测机采井生产电流,可在加入清垢剂或防垢剂的流程之间自动切换。根据生产数据和采出液离子数据,对Z井采取清垢防垢一体化加药工艺,确定了适宜的防垢剂和清垢剂加药量。现场试验结果表明,施工后采出液"分子态垢"减少,机采井示功图恢复正常,延长了检泵周期,证明该一体化加药工艺能够及时清垢,可避免停工二次卡泵,降低作业成本,解决了三元复合驱结垢严重问题,为三元复合驱大面积推广提供了技术支撑。