液晶阵列工艺中金属钼的干法刻蚀研究

为了简化液晶面板制造工序,本文初步研究了在1.1 m×1.3 m的玻璃基板上,采用Cl2/O2气体对薄膜晶体管中沟道处的金属钼进行反应离子刻蚀。经过一组正交实验,分析了功率、气压、气体比例等参数对刻蚀速率、均匀度和选择比的影响关系,并给出了刻蚀后的扫描电镜(SEM)图和不同功率参数下薄膜电学特性曲线图。结果表明,本试验中气压是影响幅度最大的因素;另外,较高的功率会使钼对下层选择比严重变差。

Highly efficient mixed-metal spinel cobaltite electrocatalysts for the oxygen evolution reaction

Cation substitution in spinel cobaltites(e.g.,ACo2O4,in which A=Mn,Fe,Co,Ni,Cu,or Zn)is a promising strategy to precisely modulate their electronic structure/properties and thus improve the corresponding electrochemical performance for water splitting.However,the fundamental principles and mechanisms are not fully understood.This research aims to systematically investigate the effects of cation substitution in spinel cobaltites derived from mixed-metal-organic frameworks on the oxygen evolution reaction(OER).Among the obtained ACo2O4 catalysts,FeCo2O4 showed excellent OER performance with a current density of 10 mA·cm^-2 at an overpotential of 164 mV in alkaline media.Both theoretical calculations and experimental results demonstrate that the Fe substitution in the crystal lattice of ACo2O4 can significantly accelerate charge transfer,thereby achieving enhanced electrochemical properties.The crystal field of spinel ACo2O4,which determines the valence states of cations A,is identified as the key factor to dictate the OER performance of these spinel cobaltites.

Design of a ZnO/Poly(vinylidene fluoride)inverse opal film for photon localization-assisted full solar spectrum photocatalysis

Owing to its photonic band gap(PBG)and slow light effects,aniline black(AB)-poly(vinylidene fluoride)(PVDF)inverse opal(IO)photonic crystal(PC)was constructed to promote the utility of light and realize photothermal synergetic catalysis.As a highly efficient reaction platform with the capability of restricting heat,a microreactor was introduced to further amplify the photothermal effects of near infrared(NIR)radiation.The photocatalytic efficiency of ZnO/0.5AB-PVDF IO(Z0.5A)increases 1.63-fold compared to that of pure ZnO film under a full solar spectrum,indicating the effectiveness of synergetic promotion by slow light and photothermal effects.Moreover,a 5.85-fold increase is achieved by combining Z0.5A with a microreactor compared to the film in a beaker.The photon localization effect of PVDF IO was further exemplified by finite-difference time-domain(FDTD)calculations.In conclusion,photonic crystal-microreactor enhanced photothermal catalysis has immense potential for alleviating the deteriorating water environment.

Thermoluminescence Response and Its Deconvolution on Crystalline Higher Order Mixtures of Alkali Halides Exposed to Gamma-Rays for Dosimetric Use

Alkali halides crystals have been the subject of intense research. High order crystalline one phase mixtures （high order： more that binary） studied by TL （thermoluminiscence technique） proved having persistent peaks along the time after the radiation to which they are exposed. In general in alkali halide crystals the traps associated with highest recorded temperature peaks in the TL due to radiation damage have greater permanence in time too. These features are useful for dosimetric applications. In this work, temperature thermoluminescence glow peaks of ternary and quaternary mixed alkali halide crystals have been studied. The study has been focused on their high temperature glow peaks after being subjected to thermal treatments at 373, 573, and 673 K. The glow peaks of high temperature were isolated and studied 24 h and 48 h after irradiation. The parameters of the recombination processes associated to these peaks were obtained using a glow peak shape method. Orders of kinetics were higher than 1.0 and the activation energy greater than 1.2 eV. The results suggest that such materials have a high potential as dosimeter and energy storage materials.

Synthesis and Structure of Ag_3PSe_4

The title compound Ag3PSe4 was synthesized by the reaction of Ag powder, P2Se5 and Se in a molar ratio of 1:1:1 at 500 C and structurally characterized by X-ray crystallography. The crystal belongs to orthorhombic, space group Pmn21 with cell parameters: a = 7.689(4), b = 6.660(3), c = 6.379(4) , V = 326.7(3) 3, Z = 2, Dc = 6.816 g/cm3, Mr = 670.42, F(000) = 584, m = 31.302 mm-1, R = 0.0606, wR = 0.1289 and S = 1.012. The 3-D structure can be regarded as constructed from the stacking of puckered AgPSe honeycomb-like sheets along the c direction, in which the Ag, P and Se atoms are bonded to each other to form a chair-like six-membered ring, and the rings then build the sheets by sharing edges.

Synthesis and Crystal Structure of (Et_4N)_2[Pd_2 (mp)_2 (mpH)_2]

Dinuclear palladium complex (Et_4N)_2[Pd_2(mp)_2 (mpH)_2 (mpH=_2-SC_6H_4OH ) (M_r = 971. 95 ) is prepared in a reaction of sodium 2-mercaptophenolate (Na_2mp) with PdCl_2. It crystallizes in monoclinic with space group P2_1/n, a=9. 088(1),b=17. 851 (4), c=12. 932(2) , β= 93. 21 (1)°, V=2094. 7(7), D_c=1. 54 g/cm￣3, F(000) = 1000, Z=2, and final R= 0. 044 and R_w= 0. 055 for 3090 reflections (I≥3σ(I)). Structure analysis revealed the multifunction chelating character of mp functions as S_tO_t(t for terminal) and S_bOH (b for bridging) in the complex.

Hydrothermal synthesis and catalytic performance of bulky titanium silicalite-1 aggregates assembled by bridged organosilane

A facile and effective method to synthesize TS‐1zeolite aggregates has been presented.The crystallization of silanized seeds and nanocrystallites led to large and irregular TS‐1zeolite aggregates ranging from5to40μm in size,based on the special sol‐gel chemistry of bridged organosilane.Epoxidation of1‐hexene and cyclohexene was used as a probe reaction to investigate the catalytic performance of the resulting materials.These TS‐1zeolite aggregates possessed both the conventional nanoparticle properties of TS‐1zeolites and variable surface hydrophilic/hydrophobic features,which enhanced the catalytic properties of hydroperoxides for alkene epoxidation.Moreover,the large aggregates effectively simplified the separation procedure during preparation and catalytic reactions.

Effective Anisotropic Dielectric Properties of Crystal Composites

Transformation fieM method （TFM） is developed to estimate the anisotropic dielectric properties of crystal composites having arbitrary shapes and dielectric properties of crystal inclusions, whose principal dielectric axis are different from those of anisotropic crystal matrix. The complicated boundary-value problem caused by inclusion shapes is circumvented by introducing a transformation electric field into the crystal composites regions, and the effective anisotropic dielectric responses are formulated in terms of the transformation field. Furthermore, the numerical results show that the effective anisotropie dielectric responses of crystal composites periodically vary as a function of the rotating angle between the principal dielectric axes of inclusion and matrix crystal materials. It is found that at larger inclusion volume fraction the inclusion shapes induce profound effect on the effective anisotropic dielectric responses.

Phase Transitions and Dielectric Properties of Lead-Free Bi0.5K0.5TiO3-BaTiO3 Piezoelectric Ceramics

Abstract： Lead-free piezoelectric ceramics of （1 - x） Bi0.5K0.5TiO3-BaTiO3 （BKT-BT） were fabricated by the solid state reaction method with normal sintering. The influence of BT addition on the crystal structure, phase transition and dielectric properties was investigated. The crystal structure and ferroelectric phase transition were studied by XRD （X-ray diffraction） and dielectric measurements. The complete solid solution of BKT-BT was observed for all compositions. In XRD results, all compositions showed a single phase perovskite structure with tetragonal symmetry at room temperature. With increasing BT content, the separation between diffraction peaks corresponded to increasing tetragonality. The phase transition temperature of ferroelectric tetragonal-paraelectric cubic （Tc） decreased with increasing BT content. As the amount of BT concentration increased, the ceramic became denser, and almost no porosity was finally obtained.

Solid State Synthesis and Structural Characterization of Binuclear Cu(I) SbPh 3 Complex 〔Cu(SbPh 3) 2I〕 2

Dimeric complex 〔Cu(SbPh 3) 2I〕 2 has been synthesized by a solid state reaction at a low heating temperature and its crystal structure has been analyzed by X ray crystallography. The crystal is monoclinic, space group P2 1/a (#14), a = 20 436(5), b=14.125(3), c=24.683(3) , β=110.67(1)°, Z=4, V =6666(2) 3; C 72 H 60 Sb 4I 2Cu 2, M r = 1792, D c = 1.787 g·cm -3 , μ (Mo Kα ) = 31.88 cm -1 , F(000)=3440, R= 0.038 and R w= 0.043 for 5632 observed reflections ( I≥3.0σ(I) ) and 361 refined parameters. The result reveals the copper and the bridging iodide atoms form an approximately planar rhomboid array. Effects of the bulkiness of the ligands upon the structures of the analogous complexes are discussed.\;

Surface Photocatalysis-TPD Spectrometer for Photochemical Kinetics

A surface photocatalysis-TPD apparatus devoted to studying kinetics and mechanism of pho- tocatalytic processes with various signal crystal surfaces has been constructed. Extremely high vacuum （-0.2 nPa） in the ionization region is obtained by using multiple ultrahigh vacuum pumps. Compared with similar instruments built previously by others~ the H2, CH4 background in the ionization region can be reduced by about two orders of magnitude, and other residual gases in the ionization region can be reduced by about an order of magnitude. Therefore, the signal-to-noise ratio for the temperature programmed desorption （TPD） and time of flight （TOF） spectra is substantially enhanced, making experimental studies of pho- tocatalytic processes on surfaces much easier. In this work, we describe the new apparatus in detail and present some preliminary studies on the photo-induced oxygen vacancy defects on TiO2（110） at 266 nm by using the TPD and TOF methods. Preliminary results suggest that the apparatus is a powerful tool for studying kinetics and mechanism of photochemical processes.

Performance and Effectiveness of UniFET^TM II MOSFET in HID Lamp Ballast

An advanced cell structure and lifetime control technology has enhanced on-resistance and reverse recovery performance of power MOSFET （metal oxide semiconductor field-effect transistor） simultaneously. This paper introduces a newly developed planar MOSFET--UniFETTM Ⅱ MOSFET--with highly improved body diode characteristics, and presents its performance and effectiveness. UniFET II MOSFET is divided into normal FET（field effect transistor）, FRFET （fast recovery field effect transistor）, and Ultra FRFET MOSFETs according to the concentration of lifetime control, and their reverse recovery times are about 70%, 25%, and 15% of that of a conventional MOSFET, respectively. To verify the performance and effectiveness of the new MOSFET, an experiment using a 150 W HID （high intensity discharge） lamp ballast that includes a mixed frequency inverter was implemented. As a result, it was verified that two UniFET Ⅱ MOSFETs can replace two conventional MOSFEs and four additional FRDs （fast recovery diodes） without MOSFET failure.

Improved nitrogen reduction electroactivity by unique MoS_(2)‐SnS_(2) heterogeneous nanoplates supported on poly(zwitterionic liquids)functionalized polypyrrole/graphene oxide

Unique MoS_(2)‐SnS_(2)heterogeneous nanoplates have successfully in‐situ grown on poly(3‐(1‐vinylimidazolium‐3‐yl)propane‐1‐sulfonate)functionalized polypyrrole/graphene oxide(PVIPS/PPy/GO).PVIPS can attract heptamolybdate ion(Mo7O246−)and Sn^(4+)as the precursors by the ion‐exchange,resulting in the simultaneous growth of 1T’‐MoS2 and the berndtite‐2T‐type hexagonal SnS_(2)by the interfacial induced effect of PVIPS.The obtained MoS_(2)‐SnS_(2)/PVIPS/PPy/GO can serve as electrocatalysts,exhibiting good NRR performance by the synergistic effect.The semi‐conducting SnS_(2)would limit the surface electron accessibility for suppressing HER process of 1T’‐MoS_(2),while metallic 1T’‐MoS_(2)might efficiently improve the NRR electroactivity of SnS_(2)by the creation of Mo‐Sn‐Sn trimer catalytic sites.Otherwise,the irreversible crystal phase transition has taken place during the NRR process.Partial 1T’‐MoS_(2)and SnS_(2)have electrochemically reacted with N_(2),and irreversibly converted into Mo^(2)N and SnxNz due to the formation of Mo−N and Sn−N bonding,meanwhile,partial SnS_(2) has been irreversibly evolved into SnS due to the reduction by the power source in the electrochemical system.It would put forward a new design idea for optimizing the preparation method and electrocatalytic activity of transition metal dichalcogenides.

Research on Reactivities of Mo Cluster. A Selective Substitution Reaction of the Bridging (dtp) Ligand and Structure of Tetranuclear Molybdenum Cluster Compound [Mo_4S_4(μ-O_2CC_6H_5)_2(dtp)_4]

The cluster compound [Mo4S4 (μ-O2CC6H5)2(dtp)4] (dtp = S2P (OEt)2)was obtained by the ligand substitution reaction of tetranuclear molybdenum cluster [Mo4S4(μ-dtp)2(dtp)4] in the mixed solvent of acetone, ethanol and water in the presence of C6H5CO2Na. It is monoclinic and crystallizesin space group C2/c, Mr =1495. 09, a=12. 175 (5) , b=22. 01 (1) , c=20.875(9) ,β=99. 04(4)°; V=5570(5) ; Z=4; Dc= 1. 78g/cm3;μ(MoKα) = 14. 52 cm-1; F(000) =2984. Final R factor is 0. 066. The result reveals that the [Mo4S4] cluster core and t-(dtp)1ligands are retained and onlyμ-bridged (dtp)1- ligands are substituted by (C6H5CO2)1in the substitution reaction, thus producing the title cluster compound,the structure of which contains two species of bidentate ligand.

EFFECTS OF HELPER PROTEINS ENCODED BY p19 AND orf1-orf2 GENES ON Cyt1Aa PROTEIN EXPRESSION IN ACRYSTALLIFEROUSSTRAIN OF BACILLUS THURINGIENSIS

A series of plasmids were constructed to examine the effects of p19 and orf1-orf2 genes from Bacillus thuringiensis on Cyt1Aa synthesis and inclusion formation. The plasmids expressed the cyt1Aa gene along with either p19 or orf1-orf2, or each of them coordinatively with p20 in the acrystalliferous strain of B. thuringiensis subsp. israelensis 4Q7. No effect on the expression of Cyt1Aa protein was found when P19 or Orf1-Orf2 co-expressed with Cyt1Aa. However, when including p20 gene, the constructs with p19 or orf1-orf2 gene produced lower yield of Cyt1Aa proteins than without p19 or orf1-orf2 gene. Electron microscopy observation and bioassay showed that P19 and Orf1-Orf2 have no influence on the crystal size and toxicity of Cyt1Aa protein. It is presumed that P19 and Orf1-Orf2 might have negative effects on Cyt1Aa synthesis in B. thuringiensis.

Application of hierarchically porous metal-organic frameworks in heterogeneous catalysis:A review

Hierarchically porous metal-organic frameworks(H-MOFs)with micro-,meso-and macropores have emerged as a popular class of crystalline porous materials that have attracted extensive interests,and they have been studied in diverse applications,especially in heterogeneous catalysis.The hierarchical structures enable sufficient diffusion and accessibility to the active sites of the molecules and permit the encapsulation of catalytic guest molecules to exploit more possibilities with enhanced catalytic performance.In this review,we have summarized the recent representative developments of H-MOFs in the field of heterogeneous catalysis,which includes oxidation reaction,hydrogenation reaction,and condensation reaction.Emphasis is placed on the multiple functions of hierarchical structures,and the catalytic activity,selectivity,stability,recyclability,etc.of the industrial utility of H-MOFs.Finally,the prospects and challenges of H-MOFs in heterogeneous catalysis and the remaining issues in this field are presented.

Enhancing the catalytic efficiency of the Heck coupling reaction by forming 5 nm Pd octahedrons using kinetic control

Heterogeneous catalysis occurs through a process of interfacial reactions; therefore, both surface facet and size control can increase catalytic efficiency. Octahedral Pd nanocrystals, enclosed by {111} facets, should be the ideal geometrical shape for Heck coupling reactions; however, it is challenging to synthesize 5 nm Pd octahedrons with a relatively uniform size distribution using existing capping-agent techniques. Here, we used palladium as a model system to investigate how the kinetics of atomic addition could be precisely controlled using a syringe pump. As a result, our method produced Pd octahedrons as small as 5 nm, which increased the catalytic efficiency of Heck coupling reactions while reducing the weight of catalyst used.

Advanced non-precious electrocatalyst of the mixed valence CoO_x nanocrystals supported on N-doped carbon nanocages for oxygen reduction

Taking advantage of the nitrogen(N)-participation and large surface area of N-doped carbon nanocages(NCNCs),the Co Ox nanocrystals are conveniently immobilized onto the NCNCs with high dispersion.The Co Ox/NCNCs hybrid exists in the mixed valence with predominant Co O over Co3O4 and demonstrates superb oxygen reduction reaction activity and stability remaining^94%current density even after operation over 100 h.These results suggest a promising strategy to develop advanced electrocatalysts with the novel NCNCs or even beyond.

Chiral Oxazaborolidine-catalyzed Asymmetric Borane Reduction of Alkyl 4-Dialkylaminophenyl Ketones

A series of alkyl 4-dialkylaminophenyl ketones were prepared and reduced asymmetrically by borane under the chiral oxazaborolidine catalysis. The results indicate that the ketones show a more obvious subsfituent effect on the enanfioselectivity than the corresponding 4-alkyl/alkoxy/alkylthiophenyl ketones in the asymmetric reduction because of the existence of a strong coordinate nitrogen atom with the boron atom in the catalyst and borane.