基于同时发射声纳环移动机器人导航系统

开发了一种能在未知环境下实现快速障碍检测与障碍回避的基于同时发射声纳环移动机器人导航系统。为了消除由于同时发射造成的串话干扰,提出了一种基于神经网络模式识别的过滤方法;并制作了由24个声纳传感器组成的声纳环安装到实际的移动机器人上,实现了扫描频率最大可达到66 Hz的全景检测。系统中应用了动态窗口法来完成快速障碍回避的运动规划。实际的导航实验表明,系统可用于室内未知环境中的移动机器人快速导航。     

Reversible Molecular Rearrangement of Slightly Acid-treated Starches

The reersible association and dissociation of starch chain populations obtained from acid-treated starches (ATSs) was investigated. Potato starch, both nonglutinous and glutinous rice starches and sago starch were suspended in 15% sulfuric acid until 1% hydroysis occured. These ATSs had relative molecular weight ranges of 25,00–29,000 daltons. In water, about half the molecules were reconstituted into large aggregates of a few million daltons. This change in molecular size depended on presence of potassium chloride. It was not observed in debranched samples. The aggregates showed a clear endothermic peak on a DSC curve. Thus, the reversibly rearranging starch chain populations were not linear, but were branched and had some type of ordered structure.     

Further Studies on the Roles of the Head and Tall Regions of the Myosin Molecule in Heat-induced Gelation

Heat induced gelation properties of the two proteolytic fragments of myosin, heavy (HMM) and light meromyosin (LMM), were studied by rigidity measurement in a band type viscometer and by a direct examination using a scanning electron microscope. A heat induced network forming ability for both LMM and HMM was found in 0.6M KCl at a pH 6.0. LMM produced gels corresponding to a reversible helix-coil transition at temperatures ranging from 40–70°C, with little evidence of aggregation as assessed from a turbidity change of the system. Contrary, HMM associated irreversibly producing a gel with increased rigidity at pH 5.0 and a salt concentration of 0.1 M. Oxidation of SH-groups appeared to be involved only in HMM and not in LMM gelation process.     

Relative Roles of the Head and Tail Portions of the Molecule in Heat-Induced Gelation of Myosin

Myosin molecules are cleaved by chymotrypsin digestion into two fragments: subfragment 1, which originates from the globular heads of myosin, and the myosin rod, which originates from the helical tail of the myosin molecule. The heat-induced gelation of these subfragments was compared to that of intact myosin by measuring rigidity, turbidity, and other physico-chemical characteristics of each system. Two features of the heat-induced gelation of myosin, aggregation and three-dimensional network formation were found to be imparted by the subfragment 1 and the rod, respectively. The former involves disulfide exchange and the latter relates to conformational changes arising from a partially irreversible helix-coil transition during heating. Possible relationships are suggested between these physicochemical changes of the myosin head and tail regions upon heating and the heat-induced gelation of myosin.     

超高效液相-串联四极杆质谱联用法同时测定并比较甘草各部位中8种成分含量

建立同时检测甘草中8种成分:22-羟基-甘草次酸、3-epi-甘草次酸、甘草次酸、甘草酸、甘草苷、芒柄花黄素、异甘草酚、甘草香豆素的超高效液相色谱-串联四极杆质谱联用法。选用胆酸作为三萜成分的内标,相思子素2"-O-β-芹菜糖苷作为酚类化合物的内标。甘草样品经粉碎用甲醇(含内标液)超声提取,采用安捷伦ZORBAX RRHD C18柱(50 mm×2.1 mm,1.8μm),以甲醇-0.1%甲酸溶液为流动相,梯度洗脱,以电喷雾电离源,采用超高效液相-串联四极杆质谱联用动态多反应监测模式测定。结果表明,8种成分检出限均小于0.048 8μg/mL,定量限均小于0.195 2μg/mL,在0.048 8~12.500 0、0.048 8~12.500 0、0.012 2~12.500 0、0.048 8~50.000 0、0.048 8~50.000 0、0.012 2~12.500 0、0.012 2~15.000 0、0.195 2~12.500 0μg/mL范围内,22-羟基-甘草次酸、3-epi-甘草次酸、甘草次酸、甘草酸、甘草苷、芒柄花黄素、异甘草酚、甘草香豆素的峰面积与质量浓度呈良好线性关系,相关系数均大于0.99;方法回收率为97.2%~113.0%间;其日内及日间精密度实验的相对标准偏差分别为2.63%~4.47%及1.75%~3.72%。该方法灵敏度高、稳定性强、操作简便、快捷、准确,可用于甘草各部位及其相关食品质量控制。     

A HIGHER ORDER EXPANSION METHOD FOR OPTIMUM DESIGN OF STRUCTURES FOR SPECIFIED FUNDAMENTAL EIGENVALUE

A higher order expansion method is presented for optimum design of structures for specified fundamental eigenvalue. The design function, fundamental eigenmode and total volume are expressed in terms of the Taylor series expansion with respect to the specified fundamental eigenvalue. A solution with null design function, where all the eigenvalues degenerate to null, is chosen as a trivial initial solution, and higher order terms are incorporated. By using the proposed method, a set of optimum designs for a wide range of fundamental eigenvalues is easily found. The proposed method is applied to an Euler-Bernoulli beam and expanded forms are presented analytically for a simply supported beam. The method is then extended to a plane truss, and the results are compared with those by an optimality criteria method.     

Anti-E. coli lmmunoglobulin Y Isolated from Egg Yolk of Immunized Chickens as a Potential Food Ingredient

Active immunoglobulin (IgY) was isolated from egg yolk of chickens immunized with formalin-treated E. coli. The antibody activity was measured by enzyme-linked immunosorbent assay using E. coli lipopolysaccharide as an antigen. The anti-E. coli IgY aggregated the bacterial cells and inhibited their growth in vitro. IgY was relatively heat-stable without loss in antibody activity by pasteurization. IgY was stable at pH above 4, but was more susceptible to pepsin than bovine IgG, while appreciable activity was retained by IgY after trypsin- and chymotrypsin-digestion. It appears possible, therefore, to use IgY for the fortification of food products, especially infant formulae.     

Functional Improvement of Alginic Acid by Conjugating with β-Lactoglobulin

Two bovine β-lactoglobulin-alginic acid (β-LG-ALG) conjugates were prepared to improve the function of ALG by using water-soluble carbodiimide and the Maillard reaction. Fluorescence studies suggested that the conformation around Trp had been changed in each conjugate and that the surface of each conjugate was covered with polysaccharide chain. Structural analyses with monoclonal antibodies indicated that the conformation around 15Val-29IIe (β -sheet) in each conjugate had changed, while the native structure was maintained around 125Thr-135Lys (α-helix). After conjugating with β -LG, ALG showed retinol-binding and high emulsifying ability. The aggregating property of ALG in acid and in the presence of Ca²⁺ was improved in each conjugate.