巫山县乡村地区公路网通达性空间格局研究

以巫山县为研究区域，运用GIS技术，以乡镇和行政村为节点单元，采用公路网密度、乡镇间直达性指数、乡镇内直达性指数、居民点道路临近性、乡镇间节点可达性指数、乡镇内节点可达性指数、干线衔接距离、地形位指数8项指标，引入熵权-TOPSIS模型，综合分析和评价巫山县乡村地区公路网通达性及其空间分布格局。研究表明，各项指标对巫山县乡村公路网的影响程度由高到低为：公路网密度＞地形位指数＞干线衔接距离＞居民点临近性＞乡镇内直达性指数＞乡镇间节点可达性指数＞乡镇内节点可达性指数＞乡镇间直达性指数；除中心城区外，各乡镇贴近度为0.170 0＞0.831 9，区域差异明显，其中铜鼓最高，当阳最低；整体上，巫山县乡村公路通达性以中等、较好等级为主，通达性空间格局总体以铜鼓、建平、三溪为核往外围扩散，与交通干线骨架吻合度较高，呈现“三核、一环、一域”的空间格局。研究成果对巫山县山区乡村公路网建设和优化有一定的指导作用，在一定程度上完善了乡村地区公路网通达性分析和评价方法。     

Solvothermal Synthesis and Structure Characterization of a 3D Hydrogen-bonded Copper Compound [Cu(H_2dhpmc)_2]·2H_2O

1 INTRODUCTION The controlled assembly of inorganic and coordination polymers from simple building blocks is an important challenge in the design of high- dimensionality systems. In the crystal engineering 'toolbox'[1], hydrogen bonding moieties are perhaps the implements used the most in the design of such supramolecular systems[2], and have been particularly strongly applied towards the synthesis of molecular magnetic materials[3~6]. Copper complexes play an important role in catalyzin…     

巫山县乡村地区公路网通达性空间格局研究

以巫山县为研究区域,运用GIS技术,以乡镇和行政村为节点单元,采用公路网密度、乡镇间直达性指数、乡镇内直达性指数、居民点道路临近性、乡镇间节点可达性指数、乡镇内节点可达性指数、干线衔接距离、地形位指数8项指标,引入熵权-TOPSIS模型,综合分析和评价巫山县乡村地区公路网通达性及其空间分布格局。研究表明,各项指标对巫山县乡村公路网的影响程度由高到低为：公路网密度＞地形位指数＞干线衔接距离＞居民点临近性＞乡镇内直达性指数＞乡镇间节点可达性指数＞乡镇内节点可达性指数＞乡镇间直达性指数;除中心城区外,各乡镇贴近度为0.170 0＞0.831 9,区域差异明显,其中铜鼓最高,当阳最低;整体上,巫山县乡村公路通达性以中等、较好等级为主,通达性空间格局总体以铜鼓、建平、三溪为核往外围扩散,与交通干线骨架吻合度较高,呈现“三核、一环、一域”的空间格局。研究成果对巫山县山区乡村公路网建设和优化有一定的指导作用,在一定程度上完善了乡村地区公路网通达性分析和评价方法。     

Syntheses, Structures and Magnetic Properties of Two Co(II) Coordination Polymers with 2,5-Pyridine Dicarboxylic Acid

1 INTRODUCTION Studies on the system comprising ions with un-quenched orbital angular moment have been ofinterest for many years in the design of new mole-cular magnetic materials[1～5], among which thecompounds of cobalt (II) ions are especially attrac…     

Synthesis,Structure, and the Second-order Nonlinear Optical Properties of a Borate-carboxylic Acid Compound: KB[L-(-)-C4_H_4O_5]_2·H_2O

A new organic-inorganic hybrid noncentrosymmetric potassium bis(malic acid)-borates KB(L-(-)-C_4H_4O_5)_2·H_2O was synthesized by solution method. It was characterized by elemental analysis, FT-IR, TGA and single-crystal X-ray crystallography. It crystallizes in the monoclinic space group P2_(1/c) with a = 5.546(6), b = 11.985(13), c = 9.952(11) ?, β = 97.522(17)°, V = 655.8(13) ?~3, Z = 2, D_c = 1.682 g/cm~3, μ(MoKa) = 0.46 mm~(–1) and F(000) = 340. 5009 reflections were measured and 2893 independent reflections(R_(int) = 0.051) were used for further refinement. Single-crystal X-ray diffraction reveals that the complex exhibits a threedimensional pseudo tunnel structure consisting of fundamental building block [B(L-(-)-C_4H_4O_5)_2]~– anions. The small cavities are occupied by the H_2O molecules, which stabilize the whole structure by O–H×××O hydrogen bonds. The complex exhibits nonlinear optical effect as high as 1.5 times that of KDP standard.     

Te_2HPO_7晶体的非线性光学特性研究

采用水热法合成了一种具有非中心对称结构的已知化合物Te_2HPO_7,并用波长为1064 nm的激光测试了其粉末倍频效应,发现相同颗粒尺寸下其倍频效应近似为KH_2PO_4的0.27倍,并且满足相位匹配条件。偶极矩计算表明,该化合物倍频效应主要源于含有孤立电子的TeO_4多面体非对称单元。另外,本文用高温差示扫描量热法研究了晶体的热稳定性,在紫外-可见-近红外分光光度计上测量了它的透过光谱。     

Synthesis and Crystal Structure of a Novel Hydrogen-Bonded Three-Dimensional Polymer [Zn(1,4-benzenedicarboxylate)-(pyridine)·H_2O]_n

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Synethesis and Crystal Structure of Bi(ethylenediamine)copper Tetracyanonickelate(Ⅱ)

The crystal structure of the title compound C8H16CuN8Ni has been determined by single crystal X-ray diffraction. The crystal is triclinic with space group P1, a=6.494(3), b=7.270(4), c=7.936(5) .A, α=106.67(3), β=91.33(4), γ=106. 80(6)°, V=341. 3(3) A3, Z==1, Mr=346. 54, F(000)=177, μ=2. 933mm-1, Dc= 1. 686 Mg/m3. The final R factor is 0. 0603 for 1214 unique ob24- served reflections [I≥2σ(I)]. The structure consists of [Cu(en)2]2+ (eh=ethylenedi amine) cations and [Ni(CN)4]2- anions linked together by two of the CN groups (the remaining two act as unidentate ligands) to form infinite chains, in the chain, the hy between the interchains also exist, with distances of 3. 160 and 3. 124 A , so it forms a three-dimensional structure of the title compound.     

Synthesis and Crystal Structure of a Three-dimensional Manganese(Ⅱ)Complex Constructed via Covalent and Hydrogen Bonds

1INTRODUCTIONCrystalengineeringofone-,two-andthree-dimensionalsupramolecularcomplexesiscurrentlyofgreatinterestowingtothefascinatingstructuraldiversityandpotentialapplicationsinmaterials,suchaselectricconductivity,magnetism,host-guestapplication,molecularrecognitionandcatalysis[1,2].Severaltypesofinteractions,suchascoordinationcovalentbond,hydrogenbond,p-pstackingandelectrostaticinteractionscanbeusedtoconstructextendedsupramolecularframeworks[3~6],butcoordinationbondingandhydrogenbondingin…     

Synthesis and Crystal Structure of a 2-D Hydrogen-bonded Supramolecular Network {[Cu_4(OH)_4(2,2'-bpy)_4(bqdc)]·2ClO_4}_n

The title compound {[Cu4(OH)4(2,2'-bpy)4(bqdc)]·2ClO4}n 1 (bqdc = 2,2'-biquino- line-4,4'-dicarboxylic acid) has been synthesized by hydrothermal method. Its crystal structure is of triclinic, space group P1 with a = 7.6561(5), b = 12.4652(8), c = 15.7501(10) , α = 80.0480(10), β = 87.7900(10), γ = 74.0800(1)o, V = 1423.65(16) 3, Z = 2, C30H23ClN5O8Cu2, Mr = 744.06, Dc = 1.736 g/cm3, μ = 1.651 mm─1, F(000) = 754, the final R = 0.0421 and wR = 0.1163 for 4973 observed reflections with I > 2σ(I). In 1, tetra-copper chair-like clusters of [Cu4(OH)4(2,2'-bpy)4]4+ are connected by bqdc ligands to form one-dimensional chains, which are further connected by hydrogen bonds to generate a two-dimensional supramolecular network .