Bis(2,4-dichloro­phen­oxy­acetato-κ2 O 1,O 1′)(5,5′-dimethyl-2,2′-bipyridine-κ2 N,N′)cobalt(II)

In the title compound, [Co(C8H5Cl2O3)(C12H12N2)], the CoII atom, lying on a twofold rotation axis, is coordinated by four O atoms from two chelating 2,4-dichloro­phen­oxy­acetate ligands and two N atoms from a 5,5′-dimethyl-2,2′-bipyridine ligand, displaying a distorted octa­hedral geometry. A three-dimensional supra­molecular structure is formed through inter­molecular C—H⋯O hydrogen bonds and π–π stacking inter­actions between the pyridine and benzene rings [centroid–centroid distance = 3.779 (2) Å]

Numerical simulation of the blasting vibration response of shallow buried tunnel in complex urban environment

Base on the phase I project of Nanjing metro line IV, the blasting vibration response of shallow buried tunnel in complex urban environment was studied with ANSYS/LS-DYNA, the real load change was simulated with the loading way of measured stress curve, and there was a consistent between numerical simulation results and the measured data. The numerical results indicated that the velocity distribution in different directions were close in the close area (0-2 m); the vertical seismic wave attenuated at the fastest speed in the transferring process, and the radial seismic wave attenuated the fastest in the excavation direction ; in the distance from 2 m to 5 m, the tangential and radial vibration of the initiating side were both obviously larger than the other side of the core tube, which was still more violent than the vertical vibration, and the difference decreases with the distance increases. In the surrounding rocks , the radial vibration velocity was the biggest and attenuated at the fastest speed, which was close to linear attenuation ;the tangential vibration velocity is the smallest with the a relatively gentler damping, the vertical vibration attenuated until 8 m and then increased gradually and the resultant velocity obeyed the exponential damping law

(5,5′-Dimethyl-2,2′-bipyridine-κ2 N,N′)(1-naphthyl­acetato-κO)(1-naphthyl­acetato-κ2 O,O′)zinc hemihydrate

In the title compound, [Zn(C12H9O2)2(C12H12N2)]·0.5H2O, the water mol­ecule lies on a twofold rotation axis. The ZnII atom is coordinated by three O atoms from two 1-naphthyl­acetate ligands, one monodentate and the other asymmetric bidentate chelate, and two N atoms from a 5,5′-dimethyl-2,2′-bipyridine ligand, giving an irregular environment. In the crystal, the complex mol­ecules are inter­linked through the water mol­ecule by O—H⋯Ocarboxyl­ate hydrogen bonds, together with weak C—H⋯O and bipyridine ring π–π stacking inter­actions [ring centroid separation = 3.761 (2) Å], giving a two-dimensional network structure

The Application of Stereo Anti-eccentrically Teaching Methods in Traditional Chinese Qigong Course

目的 探讨立体带功防偏模式在中医气功教学中的应用。方法 从气功偏差的严重后果及目前的教学现状、立体带功防偏气功教学法的目标和意义、立体带功防偏气功教学法的具体步骤等方面进行了详细的介绍。结果 2012-2013年医学气功学课程11个班级723个学生中，出现不适感的人数仅占1.8%，在一周内不适感消失的占61.5%，两周内不适感消失者达100%，没有一例严重偏差的出现，达到了安全教学的目的。结论 立体带功防偏气功教学法可以及时发现学生出现偏差的苗头并及时纠正，提高了教学的安全性，因此值得推广。Objective: To explore the use of stereo anti-eccentrically Chinese qigong teaching mode. Method: To introduce the concrete steps of Qigong teaching methods from Qigong serious consequences，deeviation and the present teaching situation, the goal and significance of stereo anti-eccentrically qigong teaching methods etc. Result: In 2013, 6 classes and 498 students, only 23（4.61%）students appeared discomfort. Within a week the improvement of discomfort students is 16（69.56%）,disappearance of discomfort students is 5（21.73%）, two weeks later,disappeared discomfort students achieve 100%, have no  emergence of severe deviation, reached the safety of teaching purpose. Conclusion: Stereo anti-eccentrically Qigong teaching method can find the first hint of deviation and correct them in time, can improve the security of teaching. so it is worth spreading

Nozzle design in a fiber spinning process for a maximal pressure gradient

The thickness of a spinneret is always a geometrical constraint in nozzle design. The geometrical form of a nozzle has a significant effect on the subsequent spinning characteristics. This paper gives an optimal condition for maximal pressure gradient through the nozzle

Poly[(μ-3,5-dinitro-2-oxidobenzoato)(μ-3-hydroxy­pyridine)copper(II)]

A new coordination polymer, [Cu(C7H2N2O7)(C5H5NO)]n, exhibits a double-chain structure, in which 3,5-dinitro-2-oxidobenzoate and 3-hydroxy­pyridine both act as bridging ligands, ­connecting adjacent copper(II) centers to form an infinite double-stranded chain. The asymmetric unit contains one CuII ion, one 3,5-dinitro-2-oxidobenzoate ligand and a 3-hydroxy­pyridine ligand. Coordination by one N atom and three O atoms from two different 3,5-dinitro-2-oxidobenzoate ligands and a 3-hydroxy­pyridine ligand creates a square-planar CuII center, which is augmented by a less tightly bonded fifth phenol O atom to form a square-pyramidal five-coordinate complex with an essentially planar base. The double-stranded chains are stabilized by intra­chain π–π inter­actions [the centroid-to-centroid distance between adjacent aromatic rings is 3.719 (7) Å], and further linked through O—H⋯O hydrogen bonds, forming a three-dimensional supra­molecular network

Tetra­aqua­bis(1-hydr­oxy-2-naphthoato-κO)zinc(II)

In the title mononuclear complex, [Zn(C11H7O3)2(H2O)4], the ZnII atom is located on a centre of inversion and is coordinated by two O atoms from two 1-hydr­oxy-2-naphthoate ligands and four water mol­ecules in an octa­hedral geometry. The structure is consolidated by inter­molecular O—H⋯O hydrogen bonding, as well as by a π–π stacking inter­action [centroid–centroid distance 3.762 (2)Å] between adjacent naphthyl ring systems