Cowpea resistance and bioactivity of two diatomaceous earths against Callosobruchus maculatus (F.) (Coleoptera: Chrysomelidae) on three cowpea varieties

The bruchid, Callosobruchus maculatus (F.) is the most important pest of stored cowpea in tropical climates. Experiments were conducted to evaluate the susceptibility of three cowpea varieties and the bioactivity of SilicoSec® and FossilShield® against this insect pest under ambient laboratory conditions at the contents 0, 0.5, 1, 1.5 and 2 g/kg of cowpea. The Dobie susceptibility index for cowpea genotypes was estimated to compare their relative tolerance to this insect pest. Adult mortality was assessed after 1, 2, 4 and 6 days of exposure followed by the evaluation of the F₁ progeny. Population increase, percentage seed damage and weight loss were assessed after three months of storage. The results showed that the CRPS and TN5-78 varieties were highly susceptible to C. maculatus, while Lori variety was moderately susceptible to the weevil. SilicoSec® and FossilShield® caused a significant and increasing bruchid mortality according to the dose rates and periods of exposure. Malathion 5% caused complete mortality after one day exposure time. SilicoSec® was more effective than FossilShield® on the three varieties of cowpea. The greatest dose of SilicoSec® and FossilShield® (2 g/kg) caused 100% mortality on all three varieties; 4 days of exposure in the Lori variety was the shortest exposure time leading to complete mortality. Regarding LD₅₀ and LD₉₅ values, it was observed that C. maculatus adults are more susceptible to SilicoSec® than to FossilShield®.The two formulations of diatomaceous earth (1.5 g/kg) reduced the F₁ progeny by more than 70%, and produced less than 10% of seed damage and weight loss for the three varieties of cowpea. The varietal resistance and the use of diatomaceous earth against C. maculatus in storage could represent an alternative to Malagrain® for the protection of the cowpea.     

牵引逆变器IGBT风冷散热试验及仿真平台搭建

IGBT散热性能是影响高速动车组在行驶过程中安全性、可靠性及动力性的重要因素。本文以某出口铰接车牵引变流器箱为试验研究载体,研制了专用风冷散热试验台;同时运用仿真软件Flotherm进行了仿真计算,通过实物试验与仿真计算的对比研究,验证了仿真计算的可行性。     

硫化矿浮选中滑石抑制剂的研究进展

许多硫化矿常与滑石等镁硅酸盐矿物共存，滑石因其良好的可浮性影响硫化矿浮选分离，影响硫化矿选矿综合指标，对于这类硫化矿常通过抑制滑石实现二者的浮选分离，故对滑石抑制剂及其作用机理进行研究有着重要的意义。本文综述了滑石抑制剂研究进展，滑石抑制剂分为无机类和有机类，无机抑制剂如水玻璃、六偏磷酸钠等在硫化矿浮选中被广泛应用，其抑制机理主要为水解后形成的物质吸附于滑石表面，从而使得滑石亲水；高分子有机抑制剂如CMC、古尔胶等对滑石抑制能力较强，选择性较好，此类药剂主要是通过羟基、羧基与滑石形成氢键、化学键，使滑石亲水，实现硫化矿与滑石的浮选分离。采用有效的高分子抑制剂是今后实现滑石与硫化矿浮选分离的主要方向，而高分子抑制剂中-OH与-COOH是抑制滑石的主要官能团，这为滑石抑制剂的改性、设计与开发提供了依据。      

镁改性活性炭强化活性污泥处理混合污水研究

基于序批式活性污泥法(SBR)工艺,将镁盐改性活性炭(MgO-PAC)与传统活性炭(PAC)混合而成MPAC材料,用于处理生活与工业混合污水。通过连续30 d的运行实验,探讨了MPAC材料对生活与工业混合污水中COD、NH4^+-N和TP的去除效果以及对污泥的比耗氧速率、沉降性能和微生物多样性的影响。结果表明,投加MPAC材料对污水中COD的去除率提升了12.7百分点,对TP的去除率提升了17.5百分点,对NH4^+-N的去除率超过86.4%。投加MPAC后处理效果更好的重要原因,在于MPAC使得活性污泥的沉降性能和比耗氧速率得到明显改善,也提升了污泥的微生物丰度。MPAC对活性污泥处理生活与工业混合污水具有强化作用。     

在线超低温预浓缩-全二维气相色谱-飞行时间质谱联用系统在大气挥发性有机物监测中的应用

采用自主研制的在线超低温预浓缩设备，连续在线采集大气样品或者连续采集苏玛罐离线样品，对样品进行超低温捕集浓缩和二次超低温冷冻聚焦，采用全二维气相色谱-飞行时间质谱联用技术分离检测浓缩后的挥发性有机物，实现对大气中C2~C12共100多种挥发性有机物的浓缩富集和定性定量分析。本研究对该方法的线性、重复性、加标回收率、检出限等性能进行表征，并与常规一维气相色谱-四极杆质谱联用系统的定性定量结果进行比较。结果表明，该方法不仅满足大气中挥发性有机物检测的性能指标要求，且组分定性定量的准确性、灵敏度等指标均优于一维气相色谱-四极杆质谱联用技术，在挥发性有机物成分较复杂的大气样品检测中具有明显优势。     

六偏磷酸钠对菱镁矿与白云石浮选分离动力学的影响

以油酸钠为捕收剂，研究了六偏磷酸钠对菱镁矿和白云石浮选行为和浮选动力学特性的影响。结果表明：不添加六偏磷酸钠时两种矿物可浮性相近，分离困难；在矿浆pH值为9-11.5的区间里，添加适量的六偏磷酸钠，菱镁矿仍保持较好的可浮性和较高的浮游速度，而白云石的可浮性和浮游速度大幅降低，从而有利于两种矿物浮选分离。菱镁矿和白云石的浮选分别符合经典一级动力学模型和二级矩形分布模型。     

Impact of 5-hydroxy methyl furfural on continuous hydrogen production from galactose and glucose feedstock with periodic recovery

A continuous stirred tank reactor (CSTR) was operated for more than 120 days with fixed hydraulic retention time of 6 h at mesophilic temperature along with a periodic recovery phase towards hydrogen production and stimulated by the existence of 5-hydroxy methyl furfural concentration (5-HMF). Interestingly, CSTR mixed with a small amount of 5-HMF, range of 0.3–0.6 g/L showed at least 50% higher hydrogen production rate than control without 5-HMF. However, when 5-HMF concentration was higher than 0.6 g/L, the performance was significantly inhibited. The bacterial community shifted by 5-HMF from Clostridium-dominated to Lactobacillus-dominated population. Regardless of the remain 5-HMF concentration in CSTR, the microbial community and hydrogen producing performance were restored by stop mixing the 5-HMF from the feedstock. The high-rate hydrogen production of 20.0 ± 1.8 L H₂/L/d was achieved in the presence of 5-HMF using the threshold information and recovery strategy.     

Exploring the photocatalytic hydrogen production potential of titania doped with alumina derived from foil waste

The multifunctional potential of a catalyst previously synthesised for thermal processes is explored by investigating its activity for photocatalytic production of H₂ from glycerol, a by-product from the manufacture of bio-diesel. The studied catalyst contains TiO₂ doped with Al₂O₃ that was derived from aluminum foil waste. This catalyst showed higher photocatalytic activity than the analogous catalyst prepared with a commercial Al₂O₃. Pt and Pd act as electron traps while the Al₂O₃ demonstrated a promotional effect, partially through proton donation. Under optimum conditions, a steady-state of 4.2 mmol H₂ gTiO₂⁻¹ hr⁻¹ was produced, which is comparable to the 4.7 mmol H₂ gTiO₂⁻¹ hr⁻¹ obtained with Pt–TiO₂, which is a standard photocatalytic material. It should be noted that the reported Pt/Pd/TiO₂-ANFL catalyst has not yet been optimised and so this result is encouraging. It is hoped that these findings can inspire more sustainable and less expensive hydrogen production, including from biomass feedstocks such as glycerol.     

国产溴化丁基橡胶在子午线轮胎气密层中的应用

研究国产溴化丁基橡胶（BIIR）在全钢载重子午线轮胎（TBR）和轿车子午线轮胎（PCR）气密层中的应用，并与进口BIIR进行对比。结果表明：在TBR和PCR气密层胶中以国产BIIR等量替代50%进口BIIR，胶料的门尼焦烧时间延长，物理性能相当，气密性提高，工艺性能较好，成品轮胎耐久性能符合国家标准要求。