无溶剂体系酶催化合成富含共轭亚油酸甘油脂的研究

采用中心组合设计和响应面方法，研究了无溶剂体系中脂肪酶催化共轭亚油酸（CLA）与油脂反应的主要影响因素。建立了二级响应面模型，模型的复相关系数为0．90。甘油酯中CLA含量随温度、反应时间、底物配比增加而提高，反应时间影响最为显著。水分含量对酸解反应具有负影响，反应温度及反应时间与水分含量有交互作用。优化的反应条件为：反应时间为8－10h，温度40－45℃，酶量200U／g油脂，底物配比1：2．5，水含量1．0％。在优化条件下，红花油中共轭亚油酸含量可达31．47％。脂肪酶催化10，12－十八碳二烯酸反应优于9，11－十八碳二烯酸。     

Focusing of Instruments

The efficiency of an important class of Newton methods (the Levenberg-Marquardt algorithm) for solving overdetermined sets of nonlinear equations is tested in finding the solution to the two-dimensional phase problem. It is seen that the nonlinearity and number of local minima of the cost function increases dramatically with the size of the object array, making these methods of little practical use for sizes greater than 6 2 6.     

High‐Resolution,Parallel Patterning of Nanoparticles via an Ion‐Induced Focusing Mask

An ion‐induced focusing mask under the simultaneous injection of ions and charged aerosols generates invisible electrostatic lenses around each opening, through which charged nanoparticles are convergently guided without depositing on the mask surface. The sizes of the created features become significantly smaller than those of the mask openings due to the focusing capability. It is not only demonstrated that material‐independent nanoparticles including proteins can be patterned as an ordered array on any surface regardless of the conductive, nonconductive, or flexible nature of the substrate, but also that the array density can be increased. Highly sensitive gas sensors based on these focused nanoparticle patterns are fabricated via the concept.     

Focusing of synchrotron radiation

Focusing of the synchrotron radiation from a storage ring using a convex lens is geometrically analysed and tested. The source radiation is supposed to have a bivariate normal distribution in its phase space both vertically and horizontally. Its modification caused by a lens is calculated as a function of distances among the source, the lens and the image plane. It is shown that the horizontal image becomes sharpest when the source is focused on the image plane. The vertical image, however, is not sharpest under this condition. The vertical distribution has more information than the horizontal; we can derive the orbit dependence of the vertical profile and the angle distribution of the radiation changing focusing.     

Construction of Nitrogen-Doped Biphasic Transition-Metal Sulfide Nanosheet Electrode for Energy-Efficient Hydrogen Production via Urea Electrolysis

Urea-assisted hybrid water splitting is a promising technology for hydrogen (H₂) production, but the lack of cost-effective electrocatalysts hinders its extensive application. Herein, it is reported that Nitrogen-doped Co₉S₈/Ni₃S₂ hybrid nanosheet arrays on nickel foam (N-Co₉S₈/Ni₃S₂/NF) can act as an active and robust bifunctional catalyst for both urea oxidation reaction (UOR) and hydrogen evolution reaction (HER), which could drive an ultrahigh current density of 400 mA cm⁻² at a low working potential of 1.47 V versus RHE for UOR, and gives a low overpotential of 111 mV to reach 10 mA cm⁻² toward HER. Further, a hybrid water electrolysis cell utilizing the synthesized N-Co₉S₈/Ni₃S₂/NF electrode as both the cathode and anode displays a low cell voltage of 1.40 V to reach 10 mA cm⁻², which can be powered by an AA battery with a nominal voltage of 1.5 V. The density functional theory (DFT) calculations decipher that N-doped heterointerfaces can synergistically optimize Gibbs free energy of hydrogen and urea, thus accelerating the catalytic kinetics of HER and UOR. This work significantly advances the development of the promising cobalt–nickel-based sulfide as a bifunctional electrocatalyst for energy-saving electrolytic H₂ production and urea-rich innocent wastewater treatment.     

Focusing of spherical Gaussian beams

Simple procedures and formulas for tracing the characteristics of a spherical Gaussian beam through a train of lenses or mirrors are described which are analogous to those used in geometrical optics to trace repeated images through an optical train.     

Focusing peopeeties of a flame

The ability of a gas burner flame to focus light rays is considered. It is shown experimentally that a flame can serve as a short focus cylindrical lens.Translated from Inzhenerno-Fizieheskii Zhurnal, Vol. 28, No. 2, pp. 315–318, February, 1975.     

波带片的聚焦特性

我们在研究中发现,文献[1]中所发表的关于菲涅尔波带片聚焦特性的结果,实际上是利用了夫朗和费近似而推导出的。本文指出,用这种方法推导出的结果,除了以瑞利准则定义的分解力外,都是不精确的,甚至是错误的。此外,本文还探讨了双相非光学波带片的聚焦特性。分析结果表明,在环数较少的情况下,对高分解力和低旁瓣的要求,双相波带片能提供正波带片或负波带片更好的折衷。     

Self-Assembly of DNA Nanostructures in Different Cations

The programmable nature of DNA allows the construction of custom-designed static and dynamic nanostructures, and assembly conditions typically require high concentrations of magnesium ions that restricts their applications. In other solution conditions tested for DNA nanostructure assembly, only a limited set of divalent and monovalent ions are used so far (typically Mg²⁺ and Na⁺). Here, we investigate the assembly of DNA nanostructures in a wide variety of ions using nanostructures of different sizes: a double-crossover motif (76 bp), a three-point-star motif (~134 bp), a DNA tetrahedron (534 bp) and a DNA origami triangle (7221 bp). We show successful assembly of a majority of these structures in Ca²⁺, Ba²⁺, Na⁺, K⁺ and Li⁺ and provide quantified assembly yields using gel electrophoresis and visual confirmation of a DNA origami triangle using atomic force microscopy. We further show that structures assembled in monovalent ions (Na⁺, K⁺ and Li⁺) exhibit up to a 10-fold higher nuclease resistance compared to those assembled in divalent ions (Mg²⁺, Ca²⁺ and Ba²⁺). Our work presents new assembly conditions for a wide range of DNA nanostructures with enhanced biostability.     

Minimizing the Carrier Collection Loss of the Neutral-Color Transparent Crystalline-silicon Solar Modules via Hybrid Electrode Design

Transparent solar cells can be used where conventional solar cells are inapplicable, such as, in glass windows of buildings; however, reports on modularization, which is essential for their commercialization, are scarce. Here, a novel modularization method has been proposed for the fabrication of transparent solar cells and a 100-cm² neutral-color transparent crystalline-silicon solar module has been developed using a hybrid electrode comprising a microgrid electrode and an edge busbar electrode. The transparent solar module exhibits a power conversion efficiency (PCE) of 11.94 and 13.14% when connected in series and in parallel, respectively, with an average visible transmittance of 20%. Additionally, the module exhibits negligible losses in PCE (lower than 0.23%) in outdoor, mechanical-load, and damp-heat (at 85°C/85% RH) stability tests, indicating high stability. The transparent solar module proposes here could facilitate the commercialization of transparent solar cells.     

有电子束聚焦作用的场发射阵列

讨论了对发射电子束具有聚焦作用的场发射阵列 ,并制作了样管。为了抑制发射电子束的发散 ,采用电子束聚焦的方法。文中给出了三种结构的聚焦方案 ,开发的透明电阻层Ni SiO2 保证了聚焦孔的刻蚀精度     

Synthesis and Characterization of Some Organic Cations Buckminsterfulleride Salts

Six new organic cations (Triphenylmethane dye, Hemicyanine dyes, calix[4]arene derivative) buckminsterfulleride salts were prepared by metathetical reaction. the products were characterized by UV-NIR, ESI-MS, ESR and FT-IR. the ESR spectra show a typical C₆₀ anion radical signal and dependence on countercations and temperature, the linewidth has an abrupt increasing at about the THF melting point and the ESR signal diminishes gradually when the temperature below 170K. the possible explanation is that the THF crystallization results in exclusion of solute from the lattice and leads to C₆₀ anion aggregation, which promotes line broadening and diamagnetic dimer of (C₆₀)₂ ^2- forming.     

Raising the Sensitivity of a Bipolar Magnetotransistor

Test results are given for a bipolar magnetotransistor (BMT), whose sensitivity is determined by the recombination mechanism, and also of a BMT with its base in a well (BMTBW), which has a response threshold. The relative current sensitivity of the BMTBW is dependent on the magnetic induction, and it increases in weak magnetic fields and attains 2000 T^–1 in measurement of the Earths magnetic field. The sensitivity changes sign as the bias voltage changes.__________Translated from Izmeritelnaya Tekhnika, No. 2, pp. 55–60, February, 2005.     

Focusing of axially symmetric flattened Gaussian beams

Abstract

We study the three-dimensional field distribution of a focused axially symmetric flattened Gaussian beam. In particular, exact closed-form expressions for the intensity along the optical axis and at the focal plane are provided, together with a comparison between our results and those pertinent to the case of a converging spherical wave diffracted by a hard-edge circular aperture. Some hints for future investigations are also given.     

Synthesis and Characterization of Some Organic Cations Buckminsterfulleride Salts

Abstract

Six new organic cations (Triphenylmethane dye, Hemicyanine dyes, calix[4]arene derivative) buckminsterfulleride salts were prepared by metathetical reaction. the products were characterized by UV-NIR, ESI-MS, ESR and FT-IR. the ESR spectra show a typical C₆₀ anion radical signal and dependence on countercations and temperature, the linewidth has an abrupt increasing at about the THF melting point and the ESR signal diminishes gradually when the temperature below 170K. the possible explanation is that the THF crystallization results in exclusion of solute from the lattice and leads to C₆₀ anion aggregation, which promotes line broadening and diamagnetic dimer of (C₆₀)₂ ^2? forming.     

Focusing characteristics of a planar solid-immersion mirror

The focusing characteristics of a planar waveguide solid-immersion mirror with parabolic design have been investigated. The solid-immersion mirror is integrated into an optical waveguide, and light focusing is achieved with a parabolic mirror parallel to the waveguide plane and waveguide mode confinement normal to the waveguide plane. Optical-quality tantala silica planar waveguides can be obtained by evaporation. The parabolic sidewall reflects over 50% of the incident waveguide mode and generates a diffraction-limited focus. The measured spot size for the solid-immersion mirror described here is less than one third of the wavelength. Polarization analysis shows that the electric field near the focal region has components parallel and normal to the polarization state of the incident beam. The planar solid-immersion mirror is essentially free of chromatic aberration, and the alignment of the illumination beam is within a fraction of degrees.