从实践的研究方法看待明清儒学的发展

马克思主义哲学与旧哲学的最大区别之一就在于马克思主义哲学中引入了重要的“实践”范畴,正如那句耳熟能详的名言所说:“以往的哲学家都是在解释世界,而关键在于改造世界。”明清之际,当资本主义萌芽在中国开始兴起的时候,以宋明理学主流的传统儒学体系产生了新的发展和转变,黄宗羲、方以智、王夫之等思想家在“经世致用”的思想影响下,对于传统儒学思想进行了批判继承和发展。明清儒学或称实学,作为中国哲学发展的重要环节,对今天我们民族文化的形成有着重要的意义,因此,了解并批判地继承明清儒学思想的精神内核,对于生活在现代社会的我们仍旧具有重要的理论和现实意义。

Understanding Molecular Dynamics with Stochastic Processes via Real or Virtual Dynamics

Molecular dynamics with the stochastic process provides a convenient way to compute structural and thermodynamic properties of chemical, biological, and materials systems. It is demonstrated that the virtual dynamics case that we proposed for the Langevin equation [J. Chem. Phys. 147, 184104 （2017）] in principle exists in other types of stochastic thermostats as well. The recommended ＂middle＂ scheme [J. Chem. Phys. 147, 034109 （2017）] of the Andersen thermostat is investigated as an example. As shown by both analytic and numerical results, while the real and virtual dynamics cases approach the same plateau of the characteristic correlation time in the high collision frequency limit, the accuracy and efficiency of sampling are relatively insensitive to the value of the collision frequency in a broad range. After we compare the behaviors of the Andersen thermostat to those of Langevin dynamics, a heuristic schematic representation thermostatting processes with molecular is proposed for understanding efficient stochastic dynamics.

Imaging features of solid pseudopapillary tumor of the pancreas on multi-detector row computed tomography

AIM： To retrospectively analyze the imaging features of solid-pseudopapillary tumors （SPTs） of the pancreas on multi-detector row computed tomography （MDCT） and define the imaging findings suggestive of malignant potential. METHODS： A total of 24 consecutive cases with surgically and pathologically confirmed SPTs of the pancreas underwent preoperative abdominal MDCT studies in our hospital. All axial CT images, CT angiographic images, and coronally and sagittally reformed images were obtained. The images were retrospectively reviewed at interactive picture archiving and communication system workstations. RESULTS： Of the 24 cases of SPTs, 11 cases （45.8%） occurred in the pancreatic head and seven （29.1%） in the tail. Eighteen were pathologically diagnosed as benign and six as malignant. MDCT diagnosis of SPTs was well correlated with the surgical and pathological results （Kappa = 0.6, P 〈 0.05）. The size of SPTs ranged from 3 to 15 cm （mean, 5.8 cm）. When the size of the tumor was greater than 6 cm （including 6 cm）, the possibilities of vascular （8 vs 1） and capsular invasion （9 vs 0） increased significantly （P 〈 0.05）.Two pathologically benign cases with vascular invasion and disrupted capsule on MDCT presented with local recurrence and hepatic metastases during follow-up about 1 year after the resection of the primary tumors. CONCLUSION： Vascular and capsular invasion with superimposed spread into the adjacent pancreatic parenchyrna and nearby structures in SPTs of the pancreas can be accurately revealed by MDCT preoperatively. These imaging findings are predictive of the malignant potential associated with the aggressive behavior of the tumor, even in the pathologically benign cases.

Hydrodynamic Performance of Multiple-Row Slotted Breakwaters

This study examines the hydrodynamic performance of multiple-row vertical slotted breakwaters. We developed a mathematical model based on an eigenfunction expansion method and a least squares technique for Stokes second-order waves. The numerical results obtained for limiting cases of double-row and triple-row walls are in good agreement with results of previous studies and experimental results. Comparisons with experimental measurements of the reflection, transmission, and dissipation coefficients （CR, Cr, and CE） for double-row walls show that the proposed mathematical model adequately reproduces most of the important features. We found that for double-row walls, the CR increases with increasing wave number, kd, and with a decreasing permeable wall part, din. The Cr follows the opposite trend. The CE slowly increases with an increasing kd for lower kd values, reaches a maximum, and then decreases again. In addition, an increasing porosity of dm would significantly decrease the CR while increasing the Cr. At lower values of kd, a decreasing porosity increases the CE, but for high values of kd, a decreasing porosity reduces the Ce. The numerical results indicate that, for triple-row walls, the effect of the arrangement of the chamber widths on hydrodynamic characteristics is not significant, except when kd〈0.5 Double-row slotted breakwaters may exhibit a good wave-absorbing performance at kd〉0.5, where by the horizontal wave force may be smaller than that of a single wall. On the other hand, the difference between double-row and triple-row vertical slotted breakwaters is marginal.

The Flip Mode of Preliminary Mooc Based College English Classroom

This study was based on self-report of a MOOC school-based college English classroom teaching practice flip. Firstly, it is based on the analysis of the typical characteristics of MOOC leveraging MOOC college English courses on the basis of the next report on the concrete practice of school-based college English MOOC construction and flipped classroom teaching. Quantitative and qualitative data on learner feedback in the survey analysis shows that based MOOC flip mode is suitable for classroom teaching college English teaching, MOOC and flipped classroom have been highly recognized by students, which gives full play to both collaborative IT and foreign language teaching the depth of integration of blended learning potential.

Experimental investigation of hypersonic flow induced separation over double wedges

Flow separation occurs over the compression comers generated by deflected control surfaces on hypersonic re-entry vehicles and in the inlet of scram jet engines. Configurations like a double wedge and double cone model are useful for studying the separated flow features. Flow fields around concave comers are relatively complicated and produce several classical viscous flow features depending on the combination of the first and second wedge or cone half apex angles. Particularly characteristic phenomena are mainly shock/boundary layer, shock/shock interaction, unsteady shear layers and non-linear shock oscillations. Although most of these basic gas dynamics characteristics are well known, it is not clear what happens at high enthalpy conditions. This paper reports a result of flow fields over a double wedge at a stagnation enthalpy of 4.8 MJ/kg. The experiment was carried out in a free piston shock tunnel at a nominal Mach number of 6.99. Schlieren and double exposure holographic interferometry were applied to visualize the flow field over the double wedge.