温室及田间条件下解淀粉芽孢杆菌菌株W19对香蕉生长、产量的促进和对香蕉镰刀菌萎蔫病的抑制研究

Plant growth-promoting rhizobacteria (PGPR) are considered to be the most promising agents for cash crop production via increasing crop yields and decreasing disease occurrence. The Bacillus amyloliquefaciens strain W19 can produce secondary metabolites (iturin and bacillomycin D) effectively against Fusarium oxysporum f. sp. cubense (FOC). In this study, the ability of a bio-organic fertilizer (BIO) containing W19 strain to promote plant growth and suppress the Fusarium wilt of banana was evaluated in both pot and field experiments. The results showed that application of BIO significantly promoted the growth and fruit yield of banana while suppressing the banana Fusarium wilt disease. To further determine the beneficial mechanisms of the strain, the colonization of green fluorescent protein-tagged strain W19 on banana roots was observed using confocal laser scanning microscopy and scanning electron microscopy. The effect of banana root exudates on the formation of biofilm of strain W19 indicated that the banana root exudates may enhance colonization. In addition, the strain W19 was able to produce indole-3-acetic acid (IAA), a plant growth-promoting hormone. The results of these experiments revealed that the application of strain W19-enriched BIO improved the banana root colonization of strain W19 and growth of banana and suppressed the Fusarium wilt. The PGPR strain W19 can be a useful biocontrol agent for the production of banana under field conditions.     

Empirical Study on the Premium Rate of First-day Traded Price of Convertible Bond

Clauses-designing of convertible bond is the main object of this article. Its final effect upon exchange market is analyzed by an empirical study, which ultimately reveals the relationship between clause-designing and the premium rate of the price on the first day. The authors select 22 pieces of comparable convertible bonds in domestic market as a sample pool, and design a regression model. Results demonstrate that market price of convertible bond is primarily determined by its value. In this case, proper designing in coupon rate, duration, or setting additional clauses, such as interest compensation clause and unconditional redemption clause, could significantly improve the premium of price on the first day. Moreover, it is precise to appraise the premium of price on the first day with the regression model, which proves that this model turns out to be a valuable reference for investors.     

Phase behavior of biodiesel/diesel-ethanol-water micro-emulsion system

The phase behavior of the biodiesel/diesel-ethanol-water micro-emulsion system is investigated with chemical titration, and the effect of the biodiesel to diesel ratio on the phase behavior is analyzed.The results indicate that there exists an isotropic single-phase region in which the system formulates stable isotropic micro-emulsions consisting of biodiesel, diesel, ethanol and water without involving any surfactants, which reveals that biodiesel can be used successfully as a surface-active agent, and that the single-phase area depends on the concentrations of different components.At higher ethanol concentrations and higher ratios of biodiesel to diesel, the width of single-phase area is increased and the maximum limit of water dissolved in the mixture of biodiesel-diesel-ethanol which form a stable single-phase micro-emulsion is increased with higher biodiesel concentrations in the case of a constant ethanol quantity.Finally, the maximum limit of dissolved water in the mixture of different components is obtained.     

Single-point preview control for unmanned high-speed4WID-4WIS vehicle path tracking

As for the actuation redundancy, strong nonlinearity and uncertainty, a kind of single-point preview control approach for the unmanned high-speed four-wheel-independent-drive & steering (4WID-4WIS) vehicle path tracking is proposed based on the control allocation and the Active Disturbance Rejection Control(ADRC) methods. The vehicle single-point preview system dynamic model for path tracking is built. The control system architecture with the control allocation unit as the core is constructed. The decouple single-point preview ADRC controller for path tracking is designed. Then the quasi-inertial parts used to generate control objectives are proposed and its rationality is discussed. The control allocation solution method for the 4WID-4WIS vehicle path tracking is subsequently presented. The simulations are conducted to illustrate the validity of the single-point preview control method proposed. The results show that the unmanned high-speed 4WID-4WIS vehicle can track the circular arc double-lane change path rapidly and accurately.     

微波膨化技术在食品中的应用研究

膨化技术作为一种新型食品生产技术,正逐步在食品工业中得到广泛的应用。微波膨化是利用微波的加热特性,使物料产生蒸气压梯度,当物料压力大于它所承受能力时瞬间出现膨化现象。由于微波的低温高效作用,使食品能较好地保留其营养成分,保持食品原有的色、香、味,保证食品的品质。介绍了微波技术的机理及应用,着重讨论了微波膨化技术的作用机理、特点及在食品中的应用,详细论述了影响淀粉微波膨化效果的主要因素。     

米蛋白饮料的研制

以碎米为原料,通过米蛋白提取,淀粉液化、糖化、调味、均质、杀菌等一系列工艺,研制出一种口感良好、老少皆宜且营养丰富的米蛋白饮料。其中蛋白提取离心后的淀粉可以进行液化、糖化,产生葡萄糖液,并加入到米蛋白提取液中进行调味,这样就可以在不额外添加其他甜味剂的情况下研制出米蛋白饮料。多余的糖液还可以用于生产葡萄糖口服液,充分利用原料,以提高经济效益和大米的综合利用价值。     

Numerical simulation on centrifugal pump compressible flow field with different gas volume fractions

In order to study the influence of gas-liquid two phase flow to a centrifugal pump perfor mance and internal flow patterns, the steady three dimensional flow with different gas volume fractions is simulated by applying the Reynolds average N-S equation and mixture gas-liquid two phase flow model, and the compressibility of gas is taken into consideration in the simulation. Then we emphatically analyzed the centrifugal pump characteristic and the gas distribution law in different gas volume fractions. The computational results show that gas volume fraction has a certain influence on the performance of the centrifugal pump, and the efficiency and head of the pump are on the decline with the increase of it. Static pressure in the impeller increases in the radial direction, but the pressure gradient in the flow direction is different under the different gas volume fractions. The gas volume is distributed mainly in the ipsilateral direction of impeller back shroud in the flow channel of the volute. On the suction side of the blade inlet there is an obvious low pressure area, which causes bubbles agglutination and higher gas volume fraction. With the gas entering passage flow, gas volume fraction in the suction decreases and the pressure surface rises gradually. Higher gas volume fraction causes air blocking phenomenon in the flow passage and the discharge capacity reduces. The increase of gas volume makes the turbulent motion within the impeller more and more intense, which leads to more and more energy loss.     

微波裂解稻壳制备活化炭的工艺研究

为了推动生物质产业链,进一步开发生物质能,从而充分有效地利用农林有机废弃物,通过微波裂解稻壳制得稻壳炭,用化学活化法制备高品质的活性炭。采用碱溶法(NaOH)除去稻壳炭中SiO2,固体碳通过化学活化法来制备高质量活性炭。选取活化剂质量比、浸渍时间、活化温度、活化时间4个因素,每个因素三水平,通过正交试验对最佳活化剂制备活性炭的工艺条件进行优化,提高稻壳的综合利用率。以碘吸附值为主要品质衡量指标。通过单因素和正交实验确定最佳活化工艺条件为以氢氧化钠作为活化剂,炭碱比为1:2,活化温度为700℃、活化时间为2 h,浸渍时间为24 h,稻壳活性炭的碘吸附值为965.22 mg/g,超过了净水用活性炭的国家二级品指标,而亚甲基蓝吸附值为148.50 mg/g,达到了净水用活性炭的国家一级品标准。     

淀粉类制品加工特性影响因素的研究

淀粉类制品的加工特性与其成分(淀粉、蛋白质、脂肪等)、添加剂(胶、乳化剂、多糖等)、加工工艺(加工温度、pH值等)等有直接关系。主要论述了淀粉类制品的成分、添加剂和加工工艺对其加工特性产生的影响,为淀粉在食品工业中的进一步应用提供参考。