您当前的位置:首页 > 论文浏览



1. chinaXiv:201810.00123 [pdf]

Hydrofluoric acid-based etching effect on the surface pit, crack, scratch, and laser damage site of fused silica optics

Taixiang Liu; Ke Yang; Zhuo Zhang; Lianghong Yan; Beicong Huang; Heyang Li; Chuanchao Zhang; Xiaodong Jiang; Hongwei Yan
分类: 化学 >> 化学物理学

Large-scale, high-power laser facility is currently a basis for the research of inertial confinement fusion (ICF). In the laser facility, fused silica optics plays irreplaceable role to conduct extremely high-intensity ultraviolet laser to fusion target. However, the surface fractures, such as surface pit, crack, scratch, and laser damage site, of the optics will lower the beam quality of transmitted laser, weaken the laser damage-resistance, shorten the lifetime of the optics, and thus limit the output performance of the laser facility. In this work, to mitigate the surface fractures, hydrofluoric acid-based (HF-based) etching effect on the surface fractures is experimentally and theoretically studied. From the experimental study, with the result of three-dimensional (3D) morphological evolution of surface fractures, it is shown that the surface fractures will be passivated and their profiles will get smoothed after etching, indicating HF-based etching is a promising way to improve the local surface quality of the fractures. Especially, it is found HF-based etching can greatly suppress the laser damage growth of laser damage site by mitigating its surface and subsurface fractures, and thus is a promising wet chemical method for repairing laser-induced damage optics. In the theoretical study, an explicit local-curvature dependent etching model is proposed. Based on this model, the result from finite difference time domain (FDTD) simulation agrees very well with that of experiment, which can reveal the detailed physical process of HF-based etching. It is demonstrated that the FDTD simulation can be a reliable and efficient way to predict the morphological evolution of the surface fractures during etching.

提交时间: 2018-11-28 点击量307下载量157 评论 0

2. chinaXiv:201810.00002 [pdf]


Chao, Zhao; Can, Xiong; Man, Qiao; Tongwei, Yuan; Jing, Wang; Yunteng, Qu; XiaoQian, Wang; Fangyao, Zhou; Zhijun, Li; Qian, Xu; Shiqi, Wang; Min, Chen; Wenyu, Wang; Yafei, Li; Yuen, Wu; Yadong, Li
分类: 化学 >> 无机化学

在这里,我们报告了一种高温气体迁移策略来制备多相的单原子铁催化剂,并展示其优良的类天然酶的活性(定义为单原子酶,SAE)。 结果表明,Fe SAE的局部定义明确的FeN4位点与含血红素的天然酶的活性金属中心高度相似。 Fe SAE表现出超级高的类过氧化物酶,氧化酶和过氧化氢酶的活性,超过了Fe3O4纳米酶40倍。更重要的是,Fe SAE可以有效活化过氧化氢(H2O2)产生羟基自由基(•OH)。 这使得其可以作为一种多相化的类Fenton系统,可以应对不断增加的环境污染。 我们的研究结果开辟了一个新的人造材料家族-模仿天然

提交时间: 2018-10-04 点击量236下载量112 评论 0

4. chinaXiv:201711.00122 [pdf]

Synthesis, Crystal Structure and Antitumor Activity of Tectochrysin-6-sulfonate

LI Wu-Wu; ZHANG Zun-Ting
分类: 化学 >> 物理化学

In order to enhance water-solubility and biological utilization rate of tectochrysin, sodium 5-hydroxyl-7-methoxyflavone-6-sulfonate (1) was synthesized and its structure was identified on the basis of 1H NMR, FT-IR and elemental analysis. 5-Hydroxyl-7-methoxyflavone-6-sulfonate was assembled with Ni(II) or Mn(II), hexaquanickel(II) bis(5-hydroxyl-7-methoxyflavone-6-sulfonate) tetrahydrate (2) and hexaquamanganese(II) bis(5-hydroxyl-7-methoxyflavone-6-sulfonate) tetrahydrate (3) were obtained and characterized by IR spectroscopy. The crystal structures of 2 and 3 were determined by X-ray single-crystal diffraction analysis. The results showed that 2 and 3 are isomorphous crystals and crystallize in monoclinic crystal system, space group C2/c. In 2 and 3, the supramolecular structures are organized into hydrophilic and hydrophobic regions. Hydrophilic regions are generated by O–H×××O hydrogen bonds among sulfonate groups, latticed water molecules and coordinated water molecules. The π-π stacking interactions assemble the flavone skeletons into columns and these columns form hydrophobic regions. The sulfonate groups play an important role as a bridge of the hydrophilic and hydrophobic regions as well as the inorganic and organic components. Three-dimensional networks of 2 and 3 are furnished by extensive array of hydrogen bonds, π-π stacking interactions and electrostatic interactions. The anti-proliferative activities of 1~3 in vitro against human leukemia cells K562 and human lung cancer cells A549 were evaluated by the standard MTT assay. The pharmacological activity results showed that the introduction of sulfonic acid groups enhanced the antitumor activity of tectochrysin.

提交时间: 2017-11-05 来自合作期刊:《结构化学》 点击量994下载量518 评论 0

5. chinaXiv:201711.00123 [pdf]

Structural Features and Biological Activities of Bioactive Compounds from Fortunella margarita (Lour.) Swingle: A Review

ZENG Hong-Liang; CHEN Pei-Lin; HUANG Can-Can; SHEN Jin-Ye; CHANG Qing; ZHENG Bao-Dong; ZHANG Yi
分类: 化学 >> 物理化学

Fortunella margarita (Lour.) Swingle, commonly known as kumquat, is the smallest citrus fruit. It thrives in southeastern China and is widely cultivated and consumed in the world due to its multiple health benefits. It has been used as an important herbal medicine in traditional Chinese medicine and also as one of the most popular fruits. There are various kinds of bioactive compounds in F. margarita, such as polysaccharides, limonoids, essential oils, flavonoids, phenolic acids, vitamins, dietary fiber, etc. In addition, many studies have reported that these bioactive compounds can be used as antioxidant, antimicrobial, hypolipidemic, drosophila lure components in functional foods, pharmaceuticals and daily chemical products due to their biological activities. This review focuses on the structural features and biological activities of polysaccharides, limonoids, essential oils and flavonoids and other bioactive substances from F. margarita and their potential applications in food, daily chemical and pharmaceutical industries.

提交时间: 2017-11-05 来自合作期刊:《结构化学》 点击量939下载量481 评论 0

6. chinaXiv:201711.00124 [pdf]

Syntheses, Crystal Structures and Characterization of Two Coordination Polymers Based on Mixed Ligands

WANG Yu-Fang; HE Chao-Jun
分类: 化学 >> 物理化学

Two new coordination polymers, namely, {[Cd1.5(bc)2(HL)].H2O}2n (1) and [Mn(ip)(H2L)(H2O)]n (2) (H2L = 3-(1H-pyrazol-4-yl)-5-(pyridin-2-yl)-1,2,4-triazole, Hbc = benzoic acid, H2ip = isophthalic acid) were constructed by solvothermal reaction. The compounds were characterized by elemental analysis, FT-IR spectroscopy, and single-crystal X-ray diffraction. Compound 1 displays a two-dimensional plane structure consisting of [Cd3(bc)2(HL)] subunits. Compound 2 possesses a one-dimensional chain structure and is further extended into a 3-D supramolecular architecture via hydrogen bonds. Moreover, photoluminescence studies showed compound 1 exhibits luminescent emissions with emission maxima at 375 nm. Magnetic susceptibility measurements of 2 indicate that domain antiferromagnetic interactions exist between Mn(II) ions. In addition, thermogravimetric properties of 1 and 2 were also measured.

提交时间: 2017-11-05 来自合作期刊:《结构化学》 点击量903下载量467 评论 0

7. chinaXiv:201711.00125 [pdf]

Synthesis, Crystal Structure and Fluorescent Properties of Silver and Cadmium Complexes

WANG Qing-Wei; LIU Bo; SUI Wei
分类: 化学 >> 物理化学

Two new complexes [Ag(bix)]n·nNAA·nH2O (1) and [Cd(NAA)(phen)2(H2O)]2·2CH3COO-·H2O (2) (bix = 1,4-bis(imidazol-1-ylmethyl)benzene, HNAA = α-naphthylacetic acid, phen = 1,10-phenanthroline) have been successfully synthesized under hydrothermal conditions. Their structures have been determined by elemental analyses, IR spectroscopy, TG and single-crystal X-ray diffraction analysis. The intermolecular hydrogen bonding or π-π stacking interactions extend the complexes into a 3D supramolecular structure. Moreover, the luminescent properties of complex 2 have been investigated in the solid state.

提交时间: 2017-11-05 来自合作期刊:《结构化学》 点击量926下载量484 评论 0

8. chinaXiv:201711.00126 [pdf]

A New Cd(II) Coordination Compound Based on 4-(1,2,4-Triazol-4-yl)phenylacetic Acid: Synthesis, Structure and Photoluminescence Property

ZHU Mei-An; GUO Xing-Zhe; XIAO Li; CHEN Shui-Sheng
分类: 化学 >> 物理化学

A new complex [Cd2(L)2(Cl)2(H2O)]n (1) was synthesized by reacting CdCl2·2.5H2O with 4-(1,2,4-triazol-4-yl)phenylacetic acid (HL) ligand. The structure of the complex was characterized by single-crystal X-ray diffraction, IR spectroscopy, elemental analysis and PXRD. Complex 1 crystallizes in triclinic, space group P21/c with a = 11.4303(8), b = 14.1792(10), c = 14.6857(10) Å, β = 96.3780(10)º, V = 2365.4(3) Å3, Z = 4, C20H16Cl2N6O5Cd2, Mr = 716.09, Dc = 2.011 g/cm3, μ = 2.069-1, S = 1.051, F(000) = 1392, the final R = 0.0458 and wR = 0.0949 for 5402 observed reflections (I > 2σ(I)). Complex 1 is a two-dimensional (2D) layer structure and non-covalent bonding interactions such as C–H···π and π···π extend the 2D to form a three-dimensional supramolecular polymer.

提交时间: 2017-11-05 来自合作期刊:《结构化学》 点击量955下载量497 评论 0

9. chinaXiv:201711.00127 [pdf]

Synthesis, Structure and Photoelectric Property of a 3D Supramolecular Zinc Coordination Polymer

LUO Ya-Nan; LIU Zhi-Chen; JIANG Hui-Ying; YU Li-Ying; YU Xiao-Yang
分类: 化学 >> 物理化学

Using a rigid azo ligand 4-[(8-hydroxy-5-quinolinyl)azo]-benzoic acid (H2L), a new supramolecular compound [Zn(L)(H2O)2]n (1) has been solvothermally synthesized and structurally characterized by X-ray single-crystal diffraction, infrared spectrum, elemental analysis, power X-ray diffraction and thermal analysis. Compound 1 crystallizes in monoclinic, space group C2/c with a = 30.372(8), b = 11.415(3), c = 9.248(3) Å, β = 106.94(3)º, V = 3067.20(15) Å3, C16H13N3O5Zn, Mr = 392.66, Z = 8, Dc = 1.701 Mg/m3; F(000) = 1600, μ = 1.636 mm−1, reflections collected: 7290, reflections unique: 2735, Rint = 0.0282, R = 0.0351, wR (all data) = 0.0919, GOOF on F2 = 1.036. Compound 1 exhibits a one-dimensional (1D) zig-zag chain structure connected into a three-dimensional (3D) supramolecular network through hydrogen bonding interactions. Fluorescent property and electrochemical property were detected on compound 1.

提交时间: 2017-11-05 来自合作期刊:《结构化学》 点击量924下载量478 评论 0

10. chinaXiv:201711.00128 [pdf]

Up-conversion Properties of Er3+/Yb3+ Co-doped Li3Ba2Gd3(MoO4)8 Phosphors

SONG Ming-Jun; ZHANG Yan; ZHANG Na-Na; WANG Lin-Tong; MENG Qin-Guo
分类: 化学 >> 物理化学

Er3+/Yb3+ co-doped Li3Ba2Gd3(MoO4)8 phosphors were synthesized by conventional solid state reaction method, and their structure and spectral properties were investigated. The diffuse reflectance spectra showed that the 4I15/2 → 4I11/2 transition of Er3+ and the 2F7/2 → 2F5/2 transition of Yb3+ ions were highly overlapped. Under the excitation of 980 nm, three up-conversion (UC) luminescence bands around 530, 555 and 660 nm were observed, corresponding to the 2H11/2 → 4I15/2, 4S3/2 → 4I15/2 and 4F9/2 → 4I15/2 transitions of Er3+ ions, respectively. The effects of the concentration and pumping power on the UC intensities of Li3Ba2Gd3(MoO4)8:Er3+/Yb3+ phosphors were investigated, and the possible UC mechanism was proposed based on the results.

提交时间: 2017-11-05 来自合作期刊:《结构化学》 点击量897下载量463 评论 0

123456  尾页  转到  [6 页/ 53 条记录]