Lipid production from sweet sorghum bagasse through yeast fermentation

Cryptococcus curvatus has great potential in fermenting unconditioned hydrolysates of sweet sorghum bagasse. With hydrolysates obtained by enzymatic hydrolysis of the solid pretreated by microwave with lime, the maximal yeast cell dry weight and lipid content were 10.83 g/l and 73.26%, respectively. For hydrolysates obtained in the same way but without lime, these two parameters were 15.50 g/l and 63.98%, respectively. During yeast fermentation, glucose and xylose were consumed simultaneously while cellobiose was released from the residual bagasse. The presence of lime, on one hand, made cellulose more accessible to enzymes as evidenced by higher total reducing sugar release compared to that without during enzymatic hydrolysis step; on the other hand, it caused the degradation of sugars to non-sugar chemicals during pretreatment step. As a result, higher lipid yield of 0.11 g/g bagasse or 0.65 ton/hectare of land was achieved from the pathway of microwave pretreatment and enzymatic hydrolysis while 0.09 g/g bagasse or 0.51 ton/hectare of land was attained from the process of lime-assisted microwave pretreatment followed by the same enzymatic saccharification.     

Enhancement of the room-temperature hydrogen sensing performance of MoO3 nanoribbons annealed in a reducing gas

Uniform-sized orthorhombic MoO₃ nanoribbons were synthesized by a simple hydrothermal method at 240 °C. The nanoribbons grew along the [001] orientation, with average length, width and thickness of approximately 20 μm, 270 nm and 90 nm, respectively. The obtained nanoribbons were further annealed in a hydrogen atmosphere at different temperatures to modify their surface states. The treatment of the nanoribbons at 300 °C significantly elevated the concentration of non-stoichiometric Mo⁵⁺ to 24.7%, much larger than the original concentration (∼14.8%). A positive relationship was found between the non-stoichiometric Mo⁵⁺, chemisorbed oxygen ion and sensor response. The sensor based on the MoO₃ nanoribbons treated at 300 °C exhibited a faster response time of approximately 10.9 s, and a higher sensor response of 17.3 towards 1000 ppm H₂, compared with the results of original tests (∼21 s and ∼5.7, respectively), indicating the significantly improved gas sensing performance of the treated MoO₃. Meanwhile, the sensor also exhibited excellent repeatability and selectivity toward hydrogen gas. The enhancement of the hydrogen gas sensing performance of treated MoO₃ nanoribbons was attributed to the more effective adjustment of the width of the depletion region on the nanoribbon surface and the height of the potential barrier at the junctions, induced by the interaction between hydrogen molecules and higher-concentration oxygen ions. Our research implied that the gas sensing performance of nanostructured metal oxides could be successfully enhanced through annealing in the reducing gas.     

罩极电动机节能降耗

短路环沉在定子的端面之下，线架底部的高度可以减小到1．5mm。这样，线圈每匝的周长减少了6mm，从而减少了端部用铜材；同时短路环的长度也有所减短，又节省了铜材。     

浅谈降低内燃机燃油消耗的若干措施

本文分析了影响内燃机燃油消耗的几大因素以及相应的节油措施,在具体的工作中对提高燃油利用率,降低燃油消耗,节约生产成本有着实际的指导意义。     

高强、高性能结构材料推广与应用的对策

推广应用高强高性能材料,既可以提高建筑结构安全等级,又可以显著减少材料消耗,实现节能减排目标。但推广与促进高强、高性能结构材料在建设工程中的应用,既需要政策支持,又需要研发和设计作基础,更要提高性价比,激发用户主动采用高强、高性能结构材料的积极性。最终达到节材节能降耗之目标。     

Anodic potential on dual-chambered microbial fuel cell with sulphate reducing bacteria biofilm

Dual chamber microbial fuel cell reactors were inoculated with a mixed culture of sulfate-reducing bacteria with anode potential being the controlling parameter. A negative poised anode potential enhanced the performance of this fuel cell while a positive poised anode potential had adverse effects on cell performance. Negative anodic potential affects the biofilm characteristics, as evidenced by electrochemical analysis. Microbial community was changed accordingly.     

真空热处理炉布料矩阵优化仿真分析

为了获得更高的加热效率和更好的温度均匀性,采用有限元软件建立了真空热处理炉加热过程仿真模型,并耦合PID算法用于温度控制。通过与实测温度对比,验证了仿真模型的准确性。借助该模型,模拟研究了布料矩阵对两种典型形状零件在真空热处理炉内加热特性的影响。模拟装炉时基于零件几何形状特征,对圆棒形工件采用顺排、叉排和环形排列3种形式,对圆盘形工件采用横排式和竖排式。研究结果表明:尽管零件形状和数量相同,但是随着布料矩阵的变化,加热效率和温度均匀性都会改变。对于圆棒形工件,采用环形排列不仅可以提高内部工件的加热速率,而且相较于叉排式可以将最大温差减小36 ℃;对于圆盘形工件,由水平式改为竖直式布料可以将最大温差由248 ℃减小至171 ℃。     

An immunosensor detects carcinoembryonic antigen by a double reduction strategy based on polyphenylamine as a sacrifice reducing agent

In this paper, a novel Ag NPs-PANI/MnO₂ tag was synthesized for the first time, and the electrochemical immunoassay for carcinoembryonic antigen (CEA) was achieved. In this experiment, gold nanoparticles (Au NPs) were used as an electrochemical sensing platform to increase conductivity and improve electrode surface capture antibody (Ab₁). We use PANI as a green sacrificial agent reduces Ag NPs and MnO₂, while improving the conductivity and electrochemical stability of the immunosensor. MnO₂ and Ag NPs effectively raise the sensitivity of the sensor by catalytically reducing hydrogen peroxide (H₂O₂) into water and oxygen to achieve a double amplified sensing signal. It is found that the surface plasmon resonance of Ag NPs has an interesting SERS characteristic structure, and the equivalent circuit simulation of the electrode assembly process results in an error of less than 10%, indicating that the electrochemical immunosensor is successfully prepared. Under optimal conditions, the electrochemical immunosensor has a linear range of 0.0005–80 ng/mL and a detection limit of 0.17 pg/mL (S/N = 3). The immunosensor is expected to be used in clinical laboratories to detect CEA and other tumor markers in human plasma for precancerous screening or surveillance.     

Organic Additives for the Enhancement of Laminar Flow in a Brain‐Vessels‐Like Microchannel Assembly

Organic polymers were extracted from okra, aloe vera, and hibiscus leaves and used as drag‐reducing additives (DRAs) to enhance the laminar flow in custom‐made microchannels that simulate the human brain vessels. The experiment was conducted using an open‐loop microfluidic system. The flow enhancement performance was evaluated as the function of percentage of flow increment of mucilage additives at different concentrations. Okra mucilage showed greater flow enhancement performance at higher mucilage concentration while both aloe vera and hibiscus mucilage performed better at lower additive concentration. The findings prove the potential of these organic polymers as DRAs to enhance the blood flow.     

9号高炉热风炉1200℃风温攻关

新钢9号炉通过稳定高风温操作,为节焦降耗起到了良好的促进作用。