水浸对含钕熔铁氨合成催化剂的影响

已有熔铁氨合成催化剂中添加稀土的报道.我们通过添加稀土得到了几种活性较高的催化剂,经进一步改进制备工艺(水浸处理后),活性又有所提高.本文利用XRD和AES等,对经水浸前后的含稀土催化剂的结构进行了测试,探讨了水浸后活性提高的原因.     

Depolymerization Study of Pakistani Lignite Coal Influence of Pre‐treatments on Product Slate

Influence of pretreatments, i.e., demineralization and pre‐soaking in some solvents on the yields of liquefied products obtained from hydro‐depolymerization of Pakistani coal in a pool of hydrogen has been discussed. Results of hydrogenation experiments demonstrated that demineralizing the coal sample prior to liquefaction caused the yields to decrease compared with the virgin coal samples. The contribution of mineral matter of coal has been evaluated by comparing the yields of liquid products of virgin and leached samples. Increase in the yields obtained from the hydrogenation experiments of swollen coal samples was not satisfactorily significant.     

晶硅太阳电池原位光老化及热致输运机理

为研究晶体硅太阳电池在标准模拟光条件下的输出特性变化规律和电池内部载流子输运特性,采用原位光老化技术对被测电池进行光照处理,按标准测试实验流程测量电池的伏安特性及光谱响应等参量,发现原位光老化后太阳电池伏安特性各项参量衰减,导致电池效率降低;短波段光谱响应微量下降,是由于原位光老化过程中电池表面产生极微量的面缺陷导致经过硅表面的微量载流子被复合;而长波段响应明显降低,是由于晶硅内大量体缺陷被激活导致长波载流子在经过硅材料内部时被复合.随后将光老化后电池退火并测量比对电池各项特性参量,结果表明,退火对光老化后电池内部深层体缺陷具有较好的修复功能,但对浅层面缺陷没有修复功能,最终造成电池伏安特性参量和光谱响应只得到部分恢复.     

水浸泡对海带中碘含量的影响

用能量色散Ｘ射线荧光分析法（ＸＲＦ）研究了水浸泡对海带中碘含量的影响．结果表明，用淡水浸泡海带可使其中８０％的碘损失掉，但仍含碘６００×１０－６～１２００×１０－６，每天食用１～２ｇ经浸泡后的湿海带即可满足成人对碘的日需要量．延长浸泡时间或用盐水浸泡可使海带中碘含量少流失１０％左右。     

凝结水精处理阳树脂硫酸根溶出特性研究

电站给水系统中存在微量的SO42-就会对金属材料造成严重腐蚀。针对目前凝结水精处理系统投运后导致核电站蒸汽发生器或炉水中SO42-含量升高的问题,采用动态循环溶出和静态浸泡的方法对几种凝结水精处理常用阳树脂的SO42-溶出行为进行了研究。结果表明,不同树脂的SO42-溶出行为有较大差异,SO42-含量在短时间内随时间增长呈上升趋势,新树脂溶出SO42-的量比旧树脂大得多。通过对溶出液进行高温和氧化处理,发现溶出物中还含有一些有机磺酸盐,它们在高温或氧化条件下会分解产生SO42-和酸性物质。     

钼、硼浸种对大豆幼苗生理特性的影响

以浙春3号大豆为研究材料，设置了不同的钼、硼浸种对大豆种子的萌发和幼苗生理特性的影响，结果表明：低浓度钼或硼有利于大豆种子的萌发，钼、硼浸种时间以12h最佳，钼浸种或不过量硼浸种将增大豆幼苗的呼吸速率，提高过氧化物酶（POD）、过氧化氢酶（CAT）和超氧化岐化酶（SOD）等抗逆性酶的活性，降低质膜透性（MP）及丙二醛（MDA）和脯氨酸（Pro)的含量，中等浓度的钼、硼浸种效果最显著，而高浓度浸种将产生相反的效果。     

Pilot-Scale Fermentation of Aqueous-Ammonia-Soaked Switchgrass

Aqueous-ammonia-steeped switchgrass was subject to simultaneous saccharification and fermentation (SSF) in two pilot-scale bioreactors (50- and 350-L working volume). Switchgrass was pretreated by soaking in ammonium hydroxide (30%) with solid to liquid ratio of 5 L ammonium hydroxide per kilogram dry switchgrass for 5 days in 75-L steeping vessels without agitation at ambient temperatures (15 to 33 °C). SSF of the pretreated biomass was carried out using Saccharomyces cerevisiae (D₅A) at approximately 2% glucan and 77 filter paper units per gram cellulose enzyme loading (Spezyme CP). The 50-L fermentation was carried out aseptically, whereas the 350-L fermentation was semiaseptic. The percentage of maximum theoretical ethanol yields achieved was 73% in the 50-L reactor and 52–74% in the 350-L reactor due to the difference in asepsis. The 350-L fermentation was contaminated by acid-producing bacteria (lactic and acetic acid concentrations approaching 10 g/L), and this resulted in lower ethanol production. Despite this problem, the pilot-scale SSF of aqueous-ammonia-pretreated switchgrass has shown promising results similar to laboratory-scale experiments. This work demonstrates challenges in pilot-scale fermentations with material handling, aseptic conditions, and bacterial contamination for cellulosic fermentations to biofuels.     

Physical Treatment Reduces Trypsin Inhibitor Activity and Modifies Chemical Composition of Marama Bean (Tylosema esculentum)

The utility of the marama bean (MB) as an alternative protein source to soybean (SB) can be limited by the high concentration of trypsin inhibitors (TI). The physical treatment of MB has the potential to ameliorate the antinutritional activities of TI and modify other chemical components. Thus, this study investigated the effects of physical treatments on the chemical components and trypsin inhibitor activity (TIA) of raw MB and SB. The bean substrates were subjected to each of the following treatment methods: (1) room temperature (20–22 °C) soaking for 24 h; (2) electric stove cooking at 100 °C for 10, 20, and 30 min; (3) steam autoclaving at a temperature of 110 °C and pressure of 7 pounds per square inch (psi), as well as a temperature of 121 °C and 7 psi for 5, 15, and 30 min; (4) pre-soaked autoclaving at 110 °C (7 psi) and 121 °C (17 psi) for 5, 15, and 30 min. Treated MB and SB had greater (p < 0.05) crude protein content than untreated samples. All the treatments (except 24 h soaking of MB) reduced (p < 0.05) the TIA and ash content. Marama and SB are similar in protein content, but their amino acids profile and TIA are quite different. Soaking for 24 h was less effective in reducing TIA in MB and SB, compared to the thermal methods, and it was detrimental to the ash and amino acids profile of the two beans. Soaking prior to autoclaving yielded beans with the lowest TI concentrations. In conclusion, thermal methods reduced the TI contents and modified the level of proximate components and amino acids profile of the beans.     

硫酸浸渍La_2O_3掺杂TiO_2光催化剂对甲基橙废水化学耗氧量的影响

采用不同浓度的硫酸溶液浸渍处理La2O3掺杂TiO2,随后经焙烧制得一系列SO24-/TiO2-La2O3光催化剂;考察了SO24-/TiO2-La2O3光催化剂对甲基橙废水溶液化学耗氧量的影响.结果表明,SO24-/TiO2-La2O3的光催化活性比TiO2-La2O3的高;H2SO4浸渍液浓度对SO24-/TiO2-La2O3的光催化活性有一定的影响,H2SO4溶液的最佳浓度为0.5mol/L.同时,催化剂的焙烧温度对其光催化活性也有一定的影响,最佳焙烧温度为500℃;而复合催化剂中La2O3的最佳掺杂量为0.3%.