固体发酵形式的转变

简述了目前固态发酵过程中各种发酵设备的优缺点,和如何选择经济适用的发酵机。     

锐孔法制作食醋微胶囊

以液态发酵醋为材料,采用锐孔-凝固浴法制作食醋微胶囊,研究海藻酸钠浓度、CaCl2浓度、食醋酸度、操作温度4个参数对食醋微胶囊化效果的影响,利用响应面分析法优化工艺条件。结果表明:操作温度(x4)、海藻酸钠浓度的二次方(x12)、食醋酸度(x3)和操作温度(x4)的交互作用(x3x4)对包埋率的影响极显著。优化回归模型为y=47.78+2.10x1+4.37x4-4.14x12+1.70x22-4.01x3x4,可用于预测食醋微胶囊的包埋率。优化条件为,海藻酸钠浓度30g/L、CaCl2浓度5g/L、食醋酸度4%、操作温度为45℃,包埋率可达75.52%。食醋胶囊为米黄色,颗粒圆整,大小均匀,具有较好的硬度和弹性。     

Effect of dry heat stabilisation on the functional properties of rice bran proteins

Rice bran was stabilised by dry heat method at 120 °C for 10–60 min, and then, protein was extracted from stabilised rice bran using weak alkali method. The storage characteristics of stabilised rice bran and the influences of dry heat pretreatment on the physicochemical properties of rice bran protein isolate were also evaluated. The results indicated that dry heat pretreatment could not only prevent rancidity of rice bran effectively, but also improve some functional properties of rice bran proteins, such as emulsifying properties, oil holding capacity, and water holding capacity. However, foaming properties and protein solubility were slightly destroyed because of heating. Rice bran was pretreated at 120 °C for 10 or 20 min and then extracted at pH 9.5, and the protein yields were 50.09% and 46.98%, respectively. Therefore, the dry heat treatment at 120 °C for 10 or 20 min was a suitable alternative process in stabilisation of rice bran.     

GBF蜂巢芯现浇混凝土密肋楼盖的经济分析

介绍了GBF蜂巢芯结构好、重量轻、造价低等特点,结合山东友邦置业有限公司开发的地下车库工程,分析了GBF蜂巢芯现浇混凝土密肋楼盖的设计原理、施工工艺流程及施工操作要点,并着重探讨了该工程采用GBF蜂巢芯现浇混凝土密肋楼盖技术所产生的经济效益。     

基于机器人听觉和视觉的目标搜索策略

提出了一种运用行为规则库和综合使用听觉信息、视觉信息来完成目标搜索的策略.该策略首先由机器人的传声器阵列和双目立体视觉摄像机采集环境信息,然后通过行为控制中心决定执行规则库中的动作完成目标搜索,从而避免使用机器人的单一感官信息造成的难题.行为规则库由4条和机器人听觉模块和视觉模块相关的规则组成.听觉模块基于五元传声器阵...     

分子筛纯化系统3起故障的原因分析及处理

分析由于空冷塔排气夹带游离水、分子筛吸附器泄漏和分子筛吸附器高温、高负荷进气造成的3起分子筛纯化系统故障,阐述相应的处理措施,最后总结从这3起故障分析和处理中获得的经验。     

Molecular beacon based bioassay for highly sensitive and selective detection of nicotinamide adenine dinucleotide and the activity of alanine aminotransferase

We have developed a new approach to detect nicotinamide adenine dinucleotide (NAD(+)) with high specificity and sensitivity using molecular beacons (MBs) and employed it in the investigation of NAD(+) related biological processes, such as calorie restriction and alanine aminotransferase (ALT) activation. The E. coli DNA ligase would catalyze the ligation of two short oligonucleotides that complement with an MB only in the presence of NAD(+), resulting in the opening of the MB and the restoration of fluorescent signal. Thanks to the high sensitivity of the MB probe and the fidelity of E. coli DNA ligase toward its substrates, this approach can detect 0.3 nM NAD(+) with high selectivity against other NAD(+) analogs. This novel assay can also provide a convenient and robust way to analyze NAD(+) in biological samples such as cell lysate. As NAD(+) plays an essential role in many biochemical processes, this method can be used to investigate NAD(+) related life processes. For instance, the effect of calorie restriction on the intracellular NAD(+) level in MCF7 cells has been studied using this new assay. Moreover, this approach was also successfully used to analyze the activity of ALT. Therefore, this novel NAD(+) assay holds wide applicability as an analytical tool in biochemical and biomedical research.     

Synthesis and photo-degradation application of WO3/TiO2 hollow spheres

A WO(3)/TiO(2) composite, hollow-sphere photocatalyst with average diameter of 320 nm and shell thickness of 50 nm was successfully prepared using a template method. UV-vis diffuse reflectance spectra illustrated that the main absorption edges of the WO(3)/TiO(2) hollow spheres were red-shifted compared to the TiO(2) hollow spheres, indicating an extension of light absorption into the visible region of the composite photocatalyst. The WO(3) and TiO(2) phases were confirmed by X-ray diffraction analysis. BET isotherms revealed that the specific surface area and average pore diameter of the hollow spheres were 40.95 m(2)/g and 19 nm, respectively. Photocatalytic experiments indicate that 78% MB was degraded by WO(3)/TiO(2) hollow spheres under visible light within 80 min. Under the same conditions, only 24% MB can be photodegraded by TiO(2). The photocatalytic mineralization of MB, catalyzed by TiO(2) and WO(3)/TiO(2), proceeded at a significantly higher rate under UV irradiation than that under visible light, and more significant was the increase in the apparent rate constant with the WO(3)/TiO(2) composite semiconductor material which was 3.2- and 3.5-fold higher than with the TiO(2) material under both UV and visible light irradiation. The increased photocatalytic activity of the coupled nanocomposites was attributed to photoelectron/hole separation efficiency and the extension of the wavelength range of photoexcitation.     

Temperature effect on synthesis of different carbon nanostructures by sulfur-assisted chemical vapor deposition

The temperature effect on synthesizing different carbon nanostructures in the range of 820−1020 °C by sulfur-assisted chemical vapor deposition is investigated. When the growth temperature is no more than 900 °C (e.g. 820, 860, and 900 °C), carbon onions can be obtained, accompanying with some fishbone-like carbon nanofibers (CNFs), graphite sheet and carbon nanotubes (CNTs). When the growth temperature is increased to 940 °C or above (e.g. 980 and 1020 °C), the products are mainly CNTs. Furthermore, by comparing the nitrogen adsorption-desorption results of samples obtained with and without sulfur addition at each temperature, it is found that the specific surface area (SSA) of products can be remarkably enlarged after introducing small amount of sulfur during growth. This is favorable to their applications in areas like electrodes of supercapacitors, adsorbents, catalyst supports, and so on.