Macroscopic quantum coherence in antiferromagnetic molecular magnets

The macroscopic quantum coherence in a biaxial antiferromagnetic molecular magnet in the presence of magnetic field acting parallel to its hard anisotropy axis is studied within the two-sublattice model. On the basis of instanton technique in the spin-coherent-state path-integral representation, both the rigorous Wentzel-Kramers-Brillouin exponent and preexponential factor for the ground-state tunnel splitting are obtained. We find that the quantum fluctuations around the classical paths can not only induce a new quantum phase previously reported by Chiolero and Loss (Phys. Rev. Lett. 80, 169 (1998)), but also have great influnence on the intensity of the ground-state tunnel splitting. Those features clearly have no analogue in the ferromagnetic molecular magnets. We suggest that they may be the universal behaviors in all antiferromagnetic molecular magnets. The analytical results are complemented by exact diagonalization calculation.Comment: 6 pages, 1 figur

4-Methyl-N-[(Z)-3-(4-methyl­phen­ylsulfon­yl)-1,3-thia­zolidin-2-yl­idene]benzene­sulfonamide

In the crystal structure of the title compound, C17H18N2O4S3, mol­ecules are connected into centrosymmetric dimers via weak inter­molecular C—H⋯π inter­actions. These dimers are further connected through a series of weak C—H⋯O hydrogen bonds, while futher C—H⋯π inter­actions involving the phenyl and thia­zoline rings are also observed. The thia­zolidine ring is twisted from the benzene rings rings by dihedral angles of 79.1 (1) and 85.0 (1)°, while the dihedral angle between two benzene rings is 76.0 (1)°

Comparing standard distribution and its Tsallis form of transverse momenta in high energy collisions

In this paper, the experimental (simulated) transverse momentum spectra of negatively charged pions produced at mid-rapidity in central nucleus-nucleus collisions at the Heavy Ion Synchrotron (SIS), Relativistic Heavy Ion Collider (RHIC), and Large Hadron Collider (LHC) energies obtained by different collaborations are selected by us to investigate, where a few simulated data are taken from the results of FOPI Collaboration who uses the IQMD transport code based on Quantum Molecular Dynamics. A two-component standard distribution and the Tsallis form of standard distribution are used to fit these data in the framework of a multisource thermal model. The excitation functions of main parameters in the two distributions are analyzed. In particular, the effective temperatures extracted from the two-component standard distribution and the Tsallis form of standard distribution are obtained, and the relation between the two types of effective temperatures is studied.Comment: 22 pages, 8 figures. Advances in High Energy Physics, accepte

Exploration to diversified teaching mode in teaching practice of pharmaceutics of Chinese medicinal herbs

为培养能够进行中药新剂型研究、解决生产实践中的关键技术和质量问题、适应现代中国制药行业发展的复合型人才是课堂教学的目标，对中药药剂学课程教学应形成“以学生为主体，以教师为主导，以教材为中心”的教学理念。使学生不仅掌握其基本理论与基本知识，而且理论与实践相结合，培养分析解决问题的能力，提高创新能力。本文对多元化模式教学法在中药药剂学课程教学的实践应用进行了探索。In order to adapt to the development trend of Chinese pharmaceutical business and the modernization of Chinese medicine, complex talents are cultivated to develop new dosage forms of Chinese medicine, solve key technologies and quality issues in production practice and adapt to the modern development of Chinese pharmaceutical industry. Teaching philosophy of pharmaceutics of Chinese medicinal herbs should be formed in a way of "student-centered, teacher-led, and textbook-centered". Thus, the students not only can master the basic theory and knowledge, but make the combination of theory and practice, which would develop the ability to analyze and solve problems and improve innovation capabilities. In this paper, a diversified teaching model was explored in teaching practice of pharmaceutics of Chinese medicinal herbs

Simultaneous and Direct Determination of Vancomycin and Cephalexin in Human Plasma by Using HPLC-DAD Coupled with Second-Order Calibration Algorithms

A simple, rapid, and sensitive method for the simultaneous determination of vancomycin and cephalexin in human plasma was developed by using HPLC-DAD with second-order calibration algorithms. Instead of a completely chromatographic separation, mathematical separation was performed by using two trilinear decomposition algorithms, that is, PARAFAC-alternative least squares (PARAFAC-ALSs) and self-weight-alternative-trilinear-decomposition- (SWATLD-) coupled high-performance liquid chromatography with DAD detection. The average recoveries attained from PARAFAC-ALS and SWATLD with the factor number of 4 (N = 4) were 101 ± 5% and 102 ± 4% for vancomycin, and 96 ± 3% and 97 ± 3% for cephalexininde in real human samples, respectively. The statistical comparison between PARAFAC-ALS and SWATLD is demonstrated to be similar. The results indicated that the combination of HPLC-DAD detection with second-order calibration algorithms is a powerful tool to quantify the analytes of interest from overlapped chromatographic profiles for complex analysis of drugs in plasma

6,6′-Dimethyl-2,2′-[oxalylbis(aza­nedi­yl)]dipyridinium dichloride acetonitrile solvate

In the crystal structure of the title compound, C14H16N4O2 2+·2Cl−·CH3CN, weak inter­molecular N—H⋯Cl hydrogen bonds are found between the H atoms bound to the pyridine and amine N atoms and the chloride anions. The asymmetric unit consits of one half cationic mol­ecule which is located on a centre of inversion, one chloride anion in a general position and one half acetonitrile mol­ecule which is located on a twofold axis. Because of symmetry, the C—H hydrogens of the acetonitrile solvent mol­ecule are disordered over two orientations

N-(6-Methyl-2-pyrid­yl)formamide

The mol­ecule of the title compound, C7H8N2O, is essentially planar with a maximum deviation of 0.0439 (1) Å from the best plane. In the crystal, N—H⋯O hydrogen bonds between self-complementary amide groups join mol­ecules into centrosymmetric dimers

Scaling behaviour and memory in heart rate of healthy human

We investigate a set of complex heart rate time series from healthy human in different behaviour states with the detrended fluctuation analysis and diffusion entropy (DE) method. It is proposed that the scaling properties are influenced by behaviour states. The memory detected by DE exhibits an approximately same pattern after a detrending procedure. Both of them demonstrate the long-range strong correlations in heart rate. These findings may be helpful to understand the underlying dynamical evolution process in the heart rate control system, as well as to model the cardiac dynamic process