一种有效的适合F-J方法从背景噪声资料中提取多阶频散曲线的台阵划分方法

近年发展起来的从地震背景噪声提取多阶频散曲线的F-J方法是一种台阵分析方法,对某一特定的研究区域内台阵的划分方式直接影响成像的效果.当研究区域地下结构较简单,且台站间距比较均匀时,可以使用简单的平移式移动阵列法;然而若研究区域地下结构复杂多变,尤其是台站间距疏密不均时,就需要根据具体的地域特征灵活划分台阵.本文介绍了一种适用于地下结构复杂及台站间距不均匀区域的台阵划分方法,具有一定的普适性.我们将其应用于美国阿拉斯加及加拿大西北部,验证了相比于简单的沿经纬度移动阵列,我们的分区方法确实大大提高了结果的分辨率,为后续反演研究区域三维速度结构提供了坚实的保障.

MHCⅠ类分子BF2*0201递呈ALV-J表位结构和递呈机制解析

MHC B2单倍型鸡对禽白血病病毒感染有较强抗性,这种抗病性可能与被MHC分子递呈的表位刺激活化的T细胞产生的免疫应答有关。本研究拟阐明MHCⅠ类分子BF2*0201递呈ALV-J表位结构和递呈机制。利用凝胶过滤层析筛选出能与MHCⅠ稳定结合的肽。利用晶体初筛试剂盒在体外培育肽和MHCⅠ的二元复合物晶体,并利用COOT、CCP4和PYMOL等软件对该晶体结构进行解析和分析。在这项研究中,作者发现二个与BF2*0201稳定结合的ALV-J CTL表位FVDFANRLI和SALQAFREV。得到一个优质晶体BF2*0201-SALQAFREV(SV9),其生长条件为1.0 mol·L^(-1)丁二酸(pH 7.0),0.1 mol·L^(-1)HEPES(pH 7.0),1%聚乙二醇单甲醚2000。解析高分辨率(1.72?)的BF2*0201-SV9复合物结构后发现BF2*0201抗原结合槽整体呈现弱负电性。保守的残基多位于抗原结合槽的两端,特异性氨基酸赋予BF2*0201中等大小的抗原结合槽。B、C和F口袋起着较重要的锚定作用,口袋残基和水分子与抗原多肽形成氢键作用,将其固定在抗原结合槽中。SV9表位构象中突出的P4-Gln和P7-Arg残基的构象特征表明该位点有被特异性TCR潜在识别的特性。BF2*0201-SV9复合物晶体结构特征有助于阐明B2单倍型MHCⅠ类分子BF2*0201递呈ALV-J表位的机制,有助于解释B2单倍型鸡对ALV存在抗性的原因,为抗病育种工作奠定理论基础。

On John Francis Davis and“Reticent”Policy

On the eve of the Opium War,J.F.Davis,His Majesty’s Chief Superintendent of British Trade in China,put forward“Reticent”policy to ease the Sino-British relations after“Napier’s Fizzle”.The“Reticent”policy is an informal foreign policy towards China,the main purpose of which is to safeguard Britain’s economic interests in China.However,due to the compromise of this policy,it aroused the dissatisfaction and resistance of British businessmen in China,so it was not implemented for a long time.After the“Reticent”policy failed,the British government turned to the“gunboat”policy.

A Corpus-Based Comparative Multidimensional Analysis of the Two English Translations of Luoyang Jialan Ji

By using the MD approach, this study aims at making a comparison between the lexical features in W. J. F. Jenner’s and Wang Yitong’s translations of Luoyang Jialan Ji (547 AD) from a multidimensional perspective. Statistics show that both the two translations belong to the General Narrative Exposition Register. However, there are significant discrepancies between the two versions in Dimension 1 “Involved versus Informational Production”, Dimension 4 “Overt Expression of Persuasion” and Dimension 5 “Abstract versus Non-Abstract Information”. The differences in Dimension 2 “Narrative versus Non-Narrative Concerns” and Dimension 3 “Explicit versus Situation-Dependent Reference” are not that significant. It is found that in Dimension 1, the information density of Wang’s version is much higher than that of Jenner’s. In Dimension 4, Wang’s version contains more overt persuasive effort than Jenner’s. In Dimension 5, the positive and negative contrast between the two versions indicates that Wang’s version provides information in a more abstract way, whereas Jenner’s in a relatively non-abstract way. Combined with typical examples in the two translation versions, this study is hoped to help better understand the translations of Luoyang Jialan Ji and conduct future studies on the translation styles of the two translators.

Crystal Structure of Macrocalyxin J

The title compound, （1α,6β, 11β,14α）-1,7：6,20-diepoxy-6,1 1-dihydroxy- 6,7-secoent- kaur- 16-ene-7,15-dione- 14-acetate （macrocalyxin J）, is a diterpenoid which was isolated from the leaves of Rabdosia macrocalyx and characterized by single-crystal X-ray diffraction. It crystallizes in orthorhombic, space group P212121 with α= 9.3608（8）, b = 14.9787（12）, c = 15.5750（13） A, Z = 4, V = 2183.8（3） A^3, C22H30O9, Mr= 438.46, Dc= 1.334 g/m^3,μ（MoKα） = 0.103 mm^-1, F（000） = 936, the final R = 0.0532 and wR = 0.1262 for 2252 observed reflections （I 〉 2σ（I））. In the molecule, three six-membered rings adopt chair, boat and slightly distorted boat conformations, respectively, while both five-membered rings have approximate envelope conformations.

基于L型轮辐结构膜片的窄频光纤F-P声波传感器研究

光纤声传感器被广泛应用在工业、医疗等领域。为了提高光纤F-P声传感器的性能,本文提出了一种L型轮辐结构的F-P传感膜片。膜片的厚度为15μm、梁宽度为0.5 mm、中心膜片的半径为1 mm。膜片由激光加工技术在304不锈钢上刻蚀而成。实验对1000 Hz下的传感器灵敏度进行研究,将传感器应用于光声池共振频率为1600 Hz的光声光谱气体检测系统中,并实现对50~100×10^(-6)的乙炔(C_(2)H_(2))气体浓度测量。实验结果表明,该传感器在1000 Hz下的声压灵敏度为25.4 nm/Pa,传感器可实现的最小可探测声压(MDP)为38.2μPa/Hz^(1/2)@1 kHz,声压信噪比为76.8 dB。实验所得到的光声光谱二次谐波信号的峰值与乙炔浓度呈现良好的线性关系,乙炔浓度的响应度为1.8 pm/10^(-6)。该传感器在光声光谱等单频声信号检测领域具有广泛的应用前景。

基于F⁃J法微动探测的表层结构调查

三维地震勘探常常处于城镇、道路等无法实施微测井等静校正方法的区域,近期人们尝试利用微动调查替代现有的静校正方法,取得了一定效果。现今微动调查在石油勘探的应用中主要通过提取面波频散曲线反演地层速度结构。该方法在石油勘探领域仍处于起步阶段,作为核心技术的频散成像方法种类繁多,其中2019年提出的频率—贝塞尔变换法(Frequency‑Bessel,F‑J)受到人们的广泛关注。相比空间自相关方法(SPAC),F‑J方法在利用背景噪声高阶模式面波成像上具有巨大优势。为了更好地研究F‑J方法的适用性,首先利用合成数据分析了不同观测系统和采集参数对F‑J成像的影响;然后利用四川某地实际噪声数据分析了不同观测系统、采集时间对F‑J频散成像的影响。实际应用中采用分段择优叠加得到的频散谱,可有效提高频散谱成像质量,为准确提取频散曲线提供了数据基础。进一步对比测井数据,发现利用基阶、高阶模式频散曲线进行多模式联合反演可精确地反演地层结构,使经济、高效地获得表层结构成为可能。

Synthesis, Crystal Structure and Luminescence of a New Two-dimensional Pb(Ⅱ) Coordination Polymer

A new two-dimensional Pb（Ⅱ） coordination polymer, [Pb2（L）（tpphz）1.5（NO3）2]·H2O（1）, has been obtained by the hydrothermal reaction of tetrapyrido[3,2-a：2′,3′-c：3′′,2′′-h：2′′′,3′′′-j]-phenazine（tpphz） and 2,2′-bipyridyl-3,3′-dicarboxylic acid（H2L）. It crystallizes in monoclinic, space group P21/c with a = 15.344（3）, b = 14.111（3）, c = 21.963（4） ？, β = 106.89（3）o, V = 4550.1（16） ？3, Z = 4, C48H26N13O11Pb2, Mr = 1375.20, Dc = 2.007 g/cm^3, F（000） = 2628, μ（Mo Ka） = 7.471 mm-1, R = 0.0339 and w R = 0.0808. In 1, the two crystallographically independent tpphz ligands adopt the same bis-chelating coordination mode, but they play different roles in the structure of 1. One type of tpphz ligands bridge the Pb（Ⅱ） cations to generate a zigzig chain, where the L anions are located on one side of the chain. Further, adjacent chains are linked by the other type of tpphz ligands into a two-dimensional layer structure. Additionally, the solid state luminescent property of 1 was also studied at room temperature.

Synthesis, Crystal Structure, Physical Properties, and Application of a Series of Functional Dibenzo[d,f][1,3]dioxepine Derivatives

The twisted aromatics, functional dibenzo[d,f][1,3]dioxepine derivatives were synthesized in high yields from reactions of 5,5＇-dibromo-2,2＇-biphenol with corresponding ketal or ketone compounds under acid catalysis. The structures of these compounds were characterized by ^1H NMR, elemental analysis, UV-Vis absorption spectrum and X-ray diffraction analysis. The conformation of O--C--O bridged biphenyl derivatives with varied substitute groups on 6,6＇-position was studied by X-ray crystallography and force-field simulation. The result of calculations by UNIVERSAL 1.02 force field in Cerius2 package（4.6） indicates that dibenzo[d,f][1,3]dioxepine derivatives show twisted conformations and the twisted angle between the phenyl rings is about 40°, which is accordant with the result from crystal structure determination, though the obtained angles in the crystal of dibenzo[d,f][1,3]dioxepine derivatives with the varied substitute groups on 6,6＇-position are shown to be slightly shifted to 40° owing to intermolecular interactions in crystal stacking. DSC studies exhibit that the substitute groups on 6,6＇-position can induce a large variation of endothermic peaks ranging from 80 to 135 ℃. The conjugated polymers based on dibenzo[d,f][1,3]dioxepine derivatives, which have ultraviolet emitting with a quantum efficiency of 10%, were obtained by Yamamoto coupling.

Ionothermal Synthesis, Crystal Structure and Antibacterial Activities of a New 3d-4f Hetero-metallic Compound Containing Two Kinds of Ligands

A new 3d-4f（CuⅡ-CeⅢ） hetero-metallic compound containing two kinds of ligands, namely [CuⅡ（H2pdc）（phen）（H2O）]（HⅢ3O）2[CeⅢ（pdc）3][CuⅡ（phen）Ce（pdc）3]（1, H2 pdc = pyridine-2,6-dicarboxylic acid, phen = 1,10-phenanthroline）, has been synthesized by an ionothermal method using the ionic liquid 3-butyl-1-methylimidazolium bromide（[Bmim]Br） as solvent, and characterized by elemental analysis, energy-dispersive X-ray spectroscopy（EDS）, IR, XPS and single-crystal X-ray diffraction. The structure reveals that 1 belongs to the triclinic system, space group P1 with a = 12.044（7）, b = 14.841（8）, c = 22.305（13） A, α = 85.802（12）, β = 85.471（12）, γ = 89.174（11）°, Z = 2, V = 3964（4） A3, Dc = 1.804 g·cm-3, F（000） = 2140, μ = 1.757 mm-1, the final R = 0.0734, wR = 0.1094 and S = 1.013. The compound can be viewed as a two-dimensional layered structure composed by 3d-4f hetero-nuclear anions [Cu（phen）Ce（pdc）3]-, coordination cations [Cu（H2pdc）（phen）（H2O）]2＋, coordination anions [Ce（pdc）3]3- and protonated water molecules via hydrogen bonding interactions and π-π stacking. Moreover, the antimicrobial activities of 1 have been also investigated. The results indicated that its inhibitory activity is slightly higher than that of penicillin against Candida albicans.

Isolation and Crystal Structure of Ent-kaurane Diterpenes from Rubus corchorifolius L. f.

In this study, ent-Kaurane-3β,16β,17-trioi （1） and ent-kaurane-2a,16β,17-triol （2）, were isolated from the leaves ofRubus corchorifolius L. f. Their structures were elucidated based on extensive spectroscopic analysis. NMR experiments identified the two compounds and X-ray crystallographic analysis confirmed their crystal structures. The crystal of 1 belongs to monoclinic with space group P21 and a = 10.7641（3）, b = 7.2789（3）, c = 11.7862（4） A, β = 95.275（3）°, V = 919.55（6） A3, Z = 2, C20H34O4, Mr = 322.49 g/mol, Dc = 1.230 g/m3, F（000） = 376, 2 = 1.54178 A,μ = 0.661 mm-1, R = 0.0319, and wR = 0.0811 for 10889 observed reflections （I〉 2σ（I））. The crystal of 2 is classified as orthorhombic with space group P212121 and a = 10.7641（3）, b = 12.72224（19）, c = 21.3929（3） A, V= 1748.94（4） A3, Z= 4, C20H3404, Mr = 322.47, De = 1.225 Mg/m3 F（000） = 712, λ = 1.54184 A,μ = 0.625 mm-1, R = 0.0303 and wR = 0.0759 for 10470 observed reflections （1〉 2σ（I））. Meanwhile, the compound revealed low inhibitory activities toward HepG2, MCF-7, and SCG-7901 cells.

二维MXene材料CrVCF_(2)的电子性质和磁性的第一性原理研究

采用基于密度泛函理论的第一性原理研究了—F官能团对Janus型MXene二维材料CrVC的结构、电子性质和磁性的影响。计算结果表明,—F官能团改变了CrVC的电子性质和磁性,CrVCF_(2)的9种可能结构的基态是铁磁态,其中CrVCF_(2)-33结构的能量最低,是最为稳定的基态结构,其磁矩为5.01μ_(B),带隙为0.099 eV,具有半导体特性。在施加-4%~+4%的双轴拉伸与压缩应变时,CrVCF_(2)-33的总磁矩保持不变;能量随着压缩或拉伸应变的增大而变大,但变化的幅度低于0.2 eV;带隙在应变的作用下会发生改变,当拉伸应变为2.4%时,带隙减小到0.005 eV,接近于零,可看作是自旋零带隙半导体。由此可知,适度的应变可调节CrVCF_(2)材料的电子能带结构,甚至可形成自旋零带隙半导体,这在自旋电子学领域具有潜在的应用价值。

A New Cadmium(Ⅱ) Coordination Polymer Constructed by 2-(2-Chloro-6-fluorophenyl)-1H-imidazo[4,5-f][1,10]phenanthroline and 1,2,3-Benzenecarboxylate: Synthesis, Structure and Luminescence

A new Cd（II） coordination polymer, namely, [Cd3（1,2,3-BTC）2（L）2]·2.25H2O （1, L = 2-（2-chloro-6-fluorophenyl）-1H-imidazo[4,5-A][1,10]phenanthroline and 1,2,3-BTC = 1,2,3-ben- zenetricarboxylate）, has been synthesized under hydrothermal conditions. The compound was characterized by single-crystal X-ray diffraction. It crystallizes in triclinic, space group Pī with α = 11.650（2）, b = 12.240（2）, c = 19.760（4） A, α = 72.01（3）, β = 77.11（3）, γ = 83.48（3）°, V = 2609.4（9） A3, Z = 2, C56H31Cd3Cl2F2N8O14.25, Mr = 1489.99, Dc = 1.896 g/cm3, F（000） = 1466, μ（MoKa） = 1.401 mm^-1, R = 0.0401 and wR = 0.1104. Compound 1 shows a 1D chain structure, and the neigh- boring 1D chains of 1 are joined together by π···π interactions to result in a 2D supramolecular layer. In addition, the luminescent property of 1 has been studied in the solid state at room temperature.

Synthesis, Crystal Structure, Thermal Behavior and Photoluminescent Property of Complex [Zn(L)(SO_4)]·0.5H_2O

Complex [Zn（L）（SO4）]0.5H20 （L = 2-（2-chloro-6-fluorophenyl）-lH-imidazo[4,5- J][1,10]phenanthroline） has been synthesized under hydrothermal conditions. The compound was characterized by elemental analysis, IR, TG and single-crystal X-ray diffraction. It crystallizes in monoclinic, space group P21/n with a = 9.9916（7）, b = 12.3834（9）, c = 29.259（2） A, fl = 97.7720（10）°, V = 3587.0（4） A^3, Z = 2, C76H41CI4F4NI60952Zn2, Mr = 1734.91, Dc = 1.606 g/cm^3, F（000） = 1754, p（MoKa） = 0.959 mm-1, R = 0.0492 and wR = 0.1385. The asymmetric unit of 1 contains one Zn（lI） atom, two L ligands, one sulfate anion and half a water molecule. Each Zn（lI） atom is five-coordinated by four nitrogen atoms from two different L ligands and one sulfate oxygen atom in a tetragonal pyramidal coordination environment. The N-H＇＂O hydrogen bonds link the discrete structure of 1 into a 2D supramolecular architecture. The photoluminescent property of 1 has also been studied in the solid state at room temperature.

Synthesis and Crystal Structure of a New Lead Coordination Polymer: [Pb(L)(1,4-ndc)]

The title coordination polymer, [Pb（L）（1,4-ndc）] 1 （L = 2-（4-fluorophenyl）-1Himidazo[4,5f1,10]phenanthroline, 1,4-ndc = naphthalene-1,4-dicarboxylic acid）, has been obtained by using hydrothermal synthesis and characterized by elemental analysis, IR and singlecrystal X-ray diffraction. It crystallizes in monoclinic, space group P21/c with a = 10.1043（11）, b = 14.3162（15）, c = 17.6061（18）, β = 95.3990（10）°, V = 2535.5（5）3, Z = 4, C31H17FN4O4Pb, Mr = 735.68, Dc = 1.927 g/cm3, F（000） = 1416, μ（MoKa） = 6.709 mm-1, R = 0.0201 and wR = 0.0489. The 1,4-ndc dianions link neighboring Pb（II） atoms in a bis-chelating mode, yielding a one-dimensional chain structure along the c axis. The C-H···π interactions between the carbon atom of L ligand and the benzene ring of 1,4-ndc lead the one-dimensional chains to form a two-dimensional supramolecular layer. The π-π interactions between L ligand and 1,4-ndc ligand make the two-dimensional layers generate a three-dimensional supramolecular architecture. Additionally, the N-H···O hydrogen bonds further stabilize the structure of 1.

Synthesis, Structure and Characterization of a New Iron Coordination Polymer:[Fe(L)(trans-1,4-chdc)]_n

A novel Fe（II） coordination polymer [Fe（L）（trans-1,4-chdc）];~ has been hydrother- mally synthesized by using 1,4-cyclohexanedicarboxylic acid （1,4-H2chdc） and 2-（2-fluoro- phenyl）-lH-imidazo[4,5-f][1,10]phenanthroline （L）. Crystallographic data： monoclinic, space group C2/c with a = 14.571（5）, b = 32.389（6）, c = 10.948（5）A, 18 = 115.186（5）°, V= 4676（3）A3, Z = 8, C27H21FFeN404, Mr = 540.33, De --- 1.535 g/cm3, F（000） = 2224, μ（MoKa） = 0.697 mmI, R = 0.0462 and wR = 0.1110. The two kinds of trans-l,4-chdc ligands link neighboring Fe（II） atoms to yield a two-dimensional layer structure. The π-π interactions between the L ligands of neighboring layers result in a three-dimensional supramolecular architecture. The IR and UV-vis spectra of the compound have been investigated in detail.

Synthesis, Structure and Photoluminescence of a New Cd(Ⅱ) Coordination Polymer Based on 4-(Carboxymethoxy)-benzoic Acid and 1,10-Phenanthroline Derivative

A new ID coordination polymer, [Cda（L1）2（L2）2].H2O （1, H2L1 = 4-（carboxy- methoxy）benzoic acid and L2 = 2-（4-fluorophenyl）-I H-imidazo[4,5-f][1,10]phenanthroline）, has been hydrothermally synthesized and characterized by elemental analysis and single-crystal X-ray diffraction. It crystallizes in triclinic, space group P1 with a = 9.985（5）, b = 10.768（5）, c = 12.512（5） A, a = 68.959（5）, β = 80.354（5）, γ = 79.663（5）°, V= 1227.4（10） A3, Z = 1, C56H36Cd2F2N8O11, Mr = 1259.73, Dc = 1.704 g/cm3, F（000） = 630, μ（MoKa） = 0.949 mm-1, R = 0.0261 and wR = 0.0655. The L1 anions link the neighboring Cd（II） atoms to form a 1D double chain structure. The L2 ligands are alternately located on both sides of the double chains. More interestingly, the lateral L2 ligands from adjacent double chains are paired to furnish strong π-π interactions, yielding a 2D supramolecular layer. N-H...O, O-H...N and O-H...O hydrogen bonds further stabilize the structure of 1. The luminescent property of 1 was studied in solid state at room temperature.

Synthesis, Crystal Structure and Biological Activity of(3S,8a R)-3-((1-Allyl-1H-3-indolyl)methyl)-hexahydropyrrolo[1,2-a]pyrazine-1,4-dione

A derivative of Brevianamide F,（3 S,8 a R）-3-（（1-allyl-1 H-3-indolyl）methyl）-hexahy-dropyrrolo[1,2-a]pyrazine-1,4-dione, was synthesized and characterized by 1 H NMR, 13 C NMR and confirmed by X-ray crystal structure analysis. This compound crystallizes in orthorhombic system, space group P212121 with a = 9.59590（10）, b = 12.70430（10）, c = 14.5425（2） ?, V = 1772.86（3） ?3, Z = 4, μ（CuK α） = 0.712 mm-1, Dc = 1.279 g/cm3, 16019 reflections measured（9.24 o≤2θ≤147.28°）, 3524 unique（Rint = 0.0309, Rsigma = 0.0175） which were used in all calculations. The final R = 0.0567（I > 2σ（I）） and w R = 0.1411（all data）. The structure exhibits intermolecular hydrogen bonds typed O–H…O, leading to the formation of one-dimensional chains. The title compound was tested for inhibitory activity toward B-16, C6, RM-1 and BV-2 cancer cell lines.

Hydrothermal Syntheses and Crystal Structures of Three Lanthanide(Ⅲ)Complexes Based on Carboxyl Derivatives of 1,10-Phenanthroline

Three lanthanide（III） complexes [Ln（4-NCP）（1,4-BDC）]n·xn H2O（Ln = Pr（1）, Sm（2）, Nd（3）. 4-HNCP = 2-（4-carboxyphenyl）imidazo（4,5-f）（1,10）phenanthroline, 1,4-H2 BDC = benzene-1,4-dicarboxylic acid） have been hydrothermally synthesized and characterized via elemental analysis, infrared spectrometry and single-crystal X-ray diffraction. Structural analyses revealed that complexes 1~3 possess similar porous three-dimensional frameworks with the point symbol {4^（12）·6~3}. Meanwhile, complexes 1~3 exhibit excellent thermal stabilities and complex 2 exhibits characteristic luminescent property.

Synthesis,Structure and Thermal Stability of a New Lead Coordination Polymer:[Pb(L1)(L2)]·1.25H2O

A new Pb（Ⅱ） coordination polymer [Pb（L1）（L2）]·1.25H2O has been synthesized with 2-（4-fluorophenyl）-1H-imidazo[4,5-f][1,10]phenanthroline （L1） and sebacic acid （H2L2） under hydrothermal conditions. Crystallographic data： triclinic, space group Pī with a=8.4890（17）, b=12.471（3）, c=14.604（3）, α=67.04（3）, β=74.08（3）, γ=85.80（3）°, V=1368.0（5）3 , Z=1, C58H59F2N8O10.5Pb2 , Mr=1488.51, Dc=1.807g/cm3 , F（000）=729, μ（MoKa）=6.221mm-1 , R=0.0283 and wR=0.0564. The L2 dianions bridge neighboring Pb（Ⅱ） atoms to form a two-dimensional layer structure. The π-π interactions between the L1 ligands of neighboring layers led to a three-dimensional supramolecular architecture. The IR and TGA of the complex have been studied in detail.