Controllable fabrication of FeCoS_(4) nanoparticles/S-doped bowl-shaped hollow carbon as efficient lithium storage anode

To address the low conductivity and easy agglomeration of transition metal sulfide nanoparticles,FeCoS_(4) nanoparticles embedded in S-doped hollow carbon(FeCoS_(4)@S-HC)composites were successfully fabricated through a combination of hydrothermal processes and sulfidation treatment.The unique bowlshaped FeCoS_(4)/S-HC composites exhibit excellent structural stability with a high specific surface area of 303.7 m^(2)·g^(-1) and a pore volume of 0.93 cm^(3)·g^(-1).When applied as anode material for lithium-ion batteries,the FeCoS_(4)@S-HC anode exhibits efficient lithium storage with high reversible specific capacity(970.2 mA·h·g^(-1) at 100 mA·g^(-1))and enhanced cycling stability(574 mA·h·g^(-1) at 0.2 A·g^(-1) after 350 cycles,a capacity retention of 84%).The excellent lithium storage is attributed to the fact that the bimetallic FeCoS_(4) nanoparticles with abundant active sites can accelerate the electrochemical reaction kinetics,and the bowl-shaped S-HC structure can provide a stable mechanical structure to suppress volume expansion.

Thermo-mechanical properties of bowl-shaped grinding wheel and machining error compensation for grinding indexable inserts

In order to meet the technical requirements of grinding the circumferential cutting edge of indexable inserts, thermo-mechanical properties of bowl-shaped grinding wheel in high speed grinding process and the influence of dimension variations of the grinding wheel on machining accuracy were investigated. Firstly, the variation trends of the dimension due to centrifugal force generated in different wheel speeds were studied and the effect of stress stiffening and spin softening was presented. Triangular heat flux distribution model was adopted to determine temperature distribution in grinding process. Temperature field cloud pictures were obtained by the finite element software. Then, dimension variation trends of wheel structure were acquired by considering the thermo-mechanical characteristic under combined action of centrifugal force and grinding heat at different speeds. A method of online dynamic monitoring and automatic compensation for dimension error of indexable insert was proposed. By experimental verification, the precision of the inserts satisfies the requirement of processing.

Preparation of bowl-shaped polydopamine surface imprinted polymer composite adsorbent for specific separation of 2'-deoxyadenosine

Molecularly imprinted polymers (MIPs) have great potential as adsorbents for selective adsorption and separation of nucleoside compounds,but effectively enhancing the affinity of recognition sites by adjusting the forces between template molecules and functional monomers remains an important challenge.In this work,a surface imprinting strategy was used to construct bowl-shaped molecularly imprinted composite sorbents (BHPN@MIPs) based on polydopamine (PDA) particles and have achieved selective separation and purification of 2'-deoxyadenosine (dA).Where by the base complementary pairing interaction of the combined template molecule d A and the pyrimidine functional monomer can enhance the preassembly force,and the hydrophilic bowl-shaped PDA can provide a larger storage space contact efficiency of d A in the test solution,causing the site utilization much higher and improving the kinetic adsorption performance.The equilibrium adsorption time and maximum adsorption capacity of60 min and 328.45μmol·g^(-1)were observed by static adsorption experiments,and the selectivity experimental results showed an imprinting factor IF of 1.30.After four adsorption–desorption cycles,the initial adsorption equilibrium adsorption capacity of BHPN@MIPs still retained 91.14%.By evaluating the selective adsorption of d A in spiked human serum solutions,BHPN@MIPs can be used to selectively enrich and analyze target d A in complex biological samples.

LOCALIZED MOLECULAR ORBITAL STUDY ON ELECTRONIC STRUCTURES OF BOWL-SHAPED AROMATIC HYDROCARBONS

The localized molecular orbitals for typical bowl-shaped circulenes are obtained by the use of INDO-LMO method. It is found that these bowl-shaped circulenes with strained π-electron systems are still aromatic and the rim π-bonds with larger localization form reactive regions for formation of buckminsterfullerene.

BOWL-SHAPED POLY(3,4-ETHYLENEDIOXYTHIOPHENE)/γ-Fe_2O_3 COMPOSITES WITH ELECROMAGNETIC FUNCTION

In this paper, electromagnetic poly（3,4-ethylenedioxythiophene）/γ-Fe2O3 （PEDOT/γ-Fe2O3 ） micro-bowls, 1-2 gm in diameter, were prepared by a simple environment-friendly process. In this method, the aqueous solution of cetyltrimethylammonium bromide （CTAB） instead of any organic solvent was used. FeC13 acted as a source of FeIII for the formation of γ-Fe2O3 and as an oxidant for the polymerization of 3,4-ethylenedioxythiophene （EDOT）. The bowl-shaped morphology of PEDOT/γ-Fe2O3 composites was strongly influenced by the concentration of CTAB, FeCl2, ammonia solution and the reaction temperature. The saturation magnetization of PEDOT/γ-Fe2O3 micro-bowls increased with the increase of FeC12 concentration and reached 6.20 AmE/kg at the FeCl2 concentration of 0.30 mol/L. The conductivity of the PEDOT/γ-Fe2O3 composites was in the range of 101 S/cm. The electrical and magnetic sources of PEDOT/γ-Fe2O3 micro-bowls were confirmed by SEM-EDX, TEM, XRD and XPS spectra. And the possible formation mechanism of PEDOT//7：Fe203 was proposed.

Synergistic antibacterial photocatalytic and photothermal properties over bowl-shaped TiO_(2)nanostructures on Ti-19Zr-10Nb-1Fe alloy

As implant substitutes are increasingly applied to the clinic,the infection caused by implants has become one of the most common complications,and the modification of the antibacterial function of the implant can reduce such complications.In this work,a well-defined bowl-shaped nanostructure coating with photocatalytic and photothermal synergistic antibacterial properties was prepared on Ti-19Zr-10Nb-1Fe(TZNF)alloy.The coating is obtained by spin-coating and sintering TiO_(2)precursors templated from self-assembled microspheres of polystyrenepoly(4-vinylpyridine)(PS-P4VP)amphiphilic block polymer on TZNF alloy.PS-P4VP provides the bowl-shaped TiO_(2)nanostructures doped with C,N elements,reducing the band-gap of TiO_(2),which can absorb near-infrared(NIR)light to release reactive oxygen species and produce photothermal conversion.The bowl structure is expected to enhance the utilization of light via the reflection in the confined space.The bowl-shaped surface has 100%antibacterial rates after 30 min of NIR light irradiation.In addition to antibacterial properties,the bowl-shaped surface has better hydrophilicity and protein adsorption capacity.The amount of protein adsorbed on TZNF with the bowl-shaped structures was six times that of TZNF.Hence,the bowl-shaped nanostructure can promote the proliferation and adhesion of osteoblasts,the cell proliferation rate was increased by 10–30%.

A novel hanging bowl-shaped mask for the fabrication of vertical sidewall structures

Contact exposure is expected to occur in conventional lithography, and can be a source of process deviations （such as shrinking and distortion of templates） during reactive ion etching and inductively coupled plasma etching, as these deviations are induced by ion bombardment. This typically results in undesired sidewall effects, such as lower sidewall angles. Here we report a novel hanging bowlshaped lithography mask that can effectively minimize sidewall effects in lithography applications. As a test case, standard silicon carbide pillars with vertical sidewalls are fabricated using this mask. The mask could be used for fabrication of high-aspect-ratio structures with ultra-violet lithography.

Activation-induce d bowl-shape d nitrogen and oxygen dual-doped carbon material and its excellent supercapacitance

Porous heteroatom-doped carbon materials exhibit promising electrochemical applications because of tunable porous structure and doping heteroatom-induced charge redistribution.Nevertheless,it is still a great challenge to develop porous heteroatom-doped carbon materials with both high-content active heteroatom species and facilitated diffusion route.Herein,we report a bowl-shaped nitrogen and oxygen dual-doping carbon(N,O-doped carbon)material based on low-temperature defluorination pyrolysis and alkali-etched activation of 3-fluorophenol-3-amino-4-hydroxypyridine-formaldehyde co-condensed resin and its excellent supercapacitance.This low-temperature thermal treatment strategy ensures high-content pyrrolic nitrogen(4.6 at.%)and oxygen species(15.9 at.%)to avoid high-temperature treatment-induced heteroatom loss and undesired configuration conversion.In these processes,the defluorination pyrolysis promotes the transformation from the resin to carbon material to some extent,and KOH activation also promotes the ordered arrangement of 002 planes,which together assure the appropriate conductivity of the final microporous carbon material.More importantly,KOH-etched activation partially removes an un-stable nano/microscale domain of the intermediate carbon microspheres to form a unique bowl-shaped structure extremely facilitating the diffusion of the substitutes and/or electrolyte ions.As expected,N,O-doped carbon material displays a remarkable specific capacitance of 486.4 F g^(−1)at 1 A g^(−1)with nitro-gen/oxygen species-dependant pseudocapacitance and good electrochemical durability.

丙磺酸型碗状碳微球制备及在餐厨废油酯交换反应中的性能研究

以碗状碳微球(BHC)为载体,合成了以烷基为磺酸基键合位点的丙磺酸型碗状碳微球(PA-CBHC-Si)。X射线光电子能谱仪、扫描电子显微镜和傅里叶变换红外光谱分析表明,三步改性分别逐步丰富BHC表面羧基(—COOH)、巯基(—SH)、磺酸基(—SO_(3)H)官能团含量,且改性过程保留了载体的原始形貌。PA-CBHC-Si的酸密度高达8.5mmol/g,活性中心—SO_(3)H于300℃开始分解,具有良好的热稳定性。PA-CBHC-Si可作为煎炸废油与甲醇酯交换反应的催化剂,醇油摩尔比为16∶1,剂油比为0.02的催化体系于130℃反应4h,脂肪酸甲酯产率为84.53%。

一种基于扼流结构的基站天线碗状振子异频去耦方法

针对双频嵌入式布局的基站天线中存在高频振子辐射性能受低频振子严重干扰的问题,提出一种基于扼流结构的基站天线碗状振子异频去耦方法。设计了含去耦结构的基站天线,在低频振子臂上加载微带形式的扼流结构,通过分析扼流结构的等效电路、在高频天线工作频段的感应电流及单站雷达散射截面(Radar Cross-Section,RCS),调整扼流结构的性能参数,有效降低低频振子对高频振子的影响。通过设计具有去耦功能的双频双极化基站天线阵列,验证所提方法的可行性。结果表明,低频振子具有良好的阻抗匹配特性,所提方法能有效减弱高频振子受低频振子影响导致的交叉极化恶化问题,且能够稳定方向图波束宽度。

基于理论承载性能与应力扩散计算的高强预应力锚索适配垫板设计方法

垫板是高强预应力锚索系统的核心组成构件,当其与锚索间适配性不足时,会出现结构可靠性低以及围岩支护效果差等问题。基于垫板的承载力学特性及其应力扩散作用,提出适配高强预应力锚索的垫板设计方法。为此,首先分析垫板的应力扩散作用与锚索的支护效应间的关联性。其次,基于不同形式垫板的结构受力特征,提出碗形垫板和平板形垫板的理论承载力计算公式,并由此计算得到满足高强预应力锚索承载性能需求的垫板型式及其结构参数。接着,通过建立“垫板(碗形、平板形)-围岩”三维数值仿真模型,分析不同型式及结构参数垫板的围岩应力扩散效果,并由此优选得到适配高强预应力锚索的垫板型式及其结构参数。最后,通过现场应用案例,分析适配垫板下高强预应力锚索系统支护效果。研究结果表明:提出的垫板设计方法实现了对高强预应力锚索系统中垫板的有效选用,适配加载300 kN的高强预应力锚索系统垫板为25 cm×25 cm×16 mm的碗形垫板,其拱高35 mm、孔口半径32 mm、碗底半径75 mm;同时,适配垫板下高强预应力锚索系统的围岩变形控制效果提升了11.9%~15.2%。研究结果有助于提升高强预应力锚索系统的可靠性与支护效果,并为预应力锚固系统中垫板的设计提供了一种可行且有效的方法。

高含量磷/硫共掺杂碳网络的制备及储钾性能的研究

为了解决掺杂碳材料中磷含量低的问题,以红磷为模板和磷源,采用等离子体增强化学气相沉积法一步合成高含量磷/硫(P/S)共掺杂碳网络材料(PSCN),并将其应用于钾离子电池。实验结果表明,P/S高含量(质量分数为31.11%)PSCN为碗状的碳网络结构,其具有碳间距大、缺陷程度高、比表面积大、微孔丰富和热稳定性好等特点。将PSCN作为钾离子电池负极时,在电流密度100 mA·g^(-1)下可逆容量达到557.1 mAh·g^(-1),在电流密度5 A·g^(-1)下可逆放电容量为140.3 mAh·g^(-1),经1 000圈循环后容量仍有137.4 mAh·g^(-1),容量保持率为69.5%,表现出优异的倍率和循环性能。而磷掺杂碳材料(PC),在电流密度100 mA·g^(-1)下的可逆容量为457.3 mAh·g^(-1),在5 A·g^(-1)下经1 000圈循环后容量仅有62.8 mAh·g^(-1),容量保持率较差为43.4%。PSCN的碗状结构有利于电解液的浸润,而其中的细小纤维可以很大程度地抑制K^(+)在嵌入/脱嵌过程中所引起的体积膨胀,从而有效地提升了钾离子电池的倍率和循环性能。此外,高含量P/S共掺杂还可以增加PSCN的活性位点,促进储钾动力学和提高离子传输能力,进而有效提升倍率性能、赝电容占比和K^(+)的扩散系数,降低反应电阻。本研究为发展钾离子电池负极材料的制备工艺提供了参考,起到理论支持作用。

离散植被冠层的解析混合BRDF模型——MGeoSAIL

根据适合于垂直单角度观测的GeoSAIL模型,改进得到适合于各种角度观测的MGeoSAIL模型。它是几何光学模型和辐射传输模型的结合。具备两种模型的优点使MGeoSAIL模型更具准确性和实用性。其中几何光学模型用来计算场景内不同情况下阴影和光照成分的比例,辐射传输模型(SAIL)考虑冠层内的辐射传输计算得到树冠的反射率和投射率,将其权重加和生成场景反射率。模拟结果表明该模型简单实用,在可见光与近红外波段均能反映出"热点"效应,在近红外波段能描述出"碗边"效应,且更适合于低密度、大个体、不连续稀疏林分冠层的BRDF模拟。

球心处有附加电极的半圆形容器等离子体源离子注入过程中鞘层的时空演化

本文利用两维流体模型研究了半圆形容器在放置共心零电位附加电极情况下,等离子体源离子注入的离子鞘层时空演化动力学过程。考察了鞘层内随时间变化的电势分布和离子密度分布,计算了容器内外表面的离子束流密度分布和注入剂量分布随时间的变化规律。研究结果显示,容器内表面附近鞘层扩展到附加电极后,其中的离子逐渐都注入到容器内表面、电场分布逐渐趋于稳定。同时,在容器内表面上,离子注入剂量不再增加。

酱汁猪肘方便菜加工及辐照工艺

研究一种酱汁猪肘方便菜生产加工新工艺。采用一种耐高温、高压、可用于热密封的碗形包装 (PP) ,4.0～ 6.0KGY辐射灭菌工艺 ,与传统的工艺相比 ,不加任何防腐剂 ,酱汁肘子外形、色泽更美观 。

HPLC法测定不同年份下关沱茶咖啡因的含量

[目的]用HPLC法比较不同年份下关沱茶咖啡因的含量。[方法]水煮法提取不同年份下关沱茶中的咖啡因，提取液离心后，采用C18柱分离，HPLC—UV检测。以甲醇溶液为流动相A，0．4％磷酸的水溶液为流动相B，进行梯度洗脱，流速为1．0ml／min，检测波长为274nm，柱温为25℃，进样量10μl。[结果]咖啡因在0．218～2．180μg范围内线性关系良好，回归方程Y=315．779X＋25．956，r为0．9999。咖啡因的平均回收率为101．3％，RSD为0．36％，5年的沱茶中咖啡因含量测定值分别为19．307、20．114、20．270、19．739、19．733mg／g，其平均值为19．832mg／g，RSD为1．90％。[结论]研究结果表明，沱茶中咖啡因的含量随生长时间的变化不大。

航空复合材料构件精确制造技术探讨及应用

随着军用航空器对作战效能比和民用航空器对燃油经济性要求的不断提升,以碳纤维增强树脂基复合材料为代表的轻量化高性能材料得以在航空器上广泛应用。国内外许多专家、学者对树脂基复合材料构件制造过程进行了大量的研究。复合材料成型工装制造时,应减少支撑块,并使用Invar钢制造的成型工装来提高复合材料构件的制造精度。在复合材料构件成型时,过低的固化压力会造成复合材料构件内部缺陷,低的升温速率和降温速率能够减少温度梯度对复合材料构件变形的影响。通过对工装补偿和优化成型工艺参数来实现盆形零件的精确制造。

酱汁猪肘方便菜辐照杀菌工艺研究

研究一种酱汁猪肘方便菜辐照杀菌工艺。检测生产过程中微生物污染水平,研究不同污染微生物种类的D10及混合菌的D10,探求产品最适宜的辐照工艺,以及辐照对产品质量的影响。与传统的工艺相比,采用4.0kGy-6.0kGy辐照杀菌工艺,避免了去钵、包装易破损以及包装后到处凝油的缺陷,有利于保持酱汁猪肘的良好外型、色泽和产品质量,延长保质期。

8英寸薄层硅外延片的均匀性控制方法

8英寸(1英寸=2.54 cm)薄层硅外延片的不均匀性是制约晶圆芯片良率水平的瓶颈之一。研究了硅外延工艺过程中影响薄外延层厚度和电阻率均匀性的关键因素,在保证不均匀性小于3%的前提下,外延层厚度和电阻率形成中间低、边缘略高的"碗状"分布可有效提高晶圆的良率水平。通过调整生长温度和氢气体积流量可实现外延层厚度的"碗状"分布,但调整温区幅度不得超过滑移线的温度门槛值。通过提高边缘温度来提高边缘10 mm和6 mm的电阻率,同时提高生长速率以提高边缘3 mm的电阻率,获得外延层电阻率的"碗状"分布,8英寸薄层硅外延片的的边缘离散现象得到明显改善,产品良率也有由原来的94%提升至98.5%,进一步提升了8英寸薄层硅外延片产业化良率水平。

结合点云占比和平滑度的碗状碎块内表面识别算法

基于内表面特性的碗状碎块重组算法可有效避免由断裂曲面引起的过分割问题,但其难点在于内表面的准确提取,为此提出一种结合点云占比和平滑度的碗状碎块内表面识别算法。首先基于区域生长算法将碗状碎块的表面分割成断裂曲面、底面、原始表面、内表面和外表面;然后根据其点云占比的显著差异从中识别出内表面和外表面,最后利用平滑度提取内表面。实验结果表明该算法能实现碗状碎块内表面的准确提取,并且具有更快的运算速度。