On the Casimir effect without cutoff

The formulation of the Casimir effect without cutoffs is discussed. Our derivation emphasizes the decisive role of the free-space electromagnetic energy density. The zero point energy arises as an energy per unit volume, i.e., as local (in x space) energy density. It is given by the vaccum expectation value of the free-space Hamiltonian density in the Fock representation corresponding to the non-trivial geometry. The two Fock representations corresponding to the system with and without plates are proved to be inequivalent.     

Schwinger’s effective lagrangian from reflection and transmission amplitudes

The reflection and transmission amplitudes are defined from the asymptotic form of the solution of Dirac equation of a charged fermion in the presence of uniform time independent external electromagnetic field (E, H). Schwinger’s effective lagrangian is derived from the reflection and transmission amplitudes. It is found that both the real and imaginary parts of the effective lagrangian agree with Schwinger’s expressions derived from the elegant method of proper time formalism.     

横向磁场中超导体感应电动势的计算

本文利用超导经典电磁理论，导出了超导体在横向磁场中切割磁感应线时感应电动势的计算公式，结果表明，与计算通常导体感应电动势的公式相同．     

Electromagnetic dissociation of 3.7 A GeV^16O in nuclear emulsion

The electromagnetic dissociation (ED) of 3.7 A GeV {}^{16}O in nuclear emulsion is investigated with high statistics. It is found that the electromagnetically dissociated cross section increases with increasing beam energy, the charge distribution of projectile fragments is the same as the results at 60 and 200 A GeV, and the production probability of projectile fragments with charge 3≤Z≤5 is less than that of the other projectile fragments. These results can be well explained by use of Weizsacker and Williams method for calculating the ED contributions. The percentile abundance of various decay modes for ED at 3.7 A GeV is close to the result at 60 and 200 A GeV, but it is different from the result at 14.6 A GeV. The ED of 3.7 A GeV is mainly caused by the giant dipole and quadrupole resonance of E1 and E2, which can be qualitatively explained by the multiplicity distribution of projectile proton in ED. The multiplicity distribution of the α fragments in ED and nuclear events have different functional forms. This difference may be a consequence of the different reaction mechanism involved.     

Enhancement of enzymatic cellulose hydrolysis using a novel type of bioreactor with intensive stirring induced by electromagnetic field

The use of the intensive mass transfer reactor (IMTR) for enzymatic saccharification of cellulose, where the reaction mixture is intensively stirred by ferromagnetic particles (FMP), enhances the process rate and productivity drastically. The most significant enhancement of the process was observed when microcrystalline cellulose was used as a substrate. A concentration of sugars up to 5% was obtained after 1 h of cellulose hydrolysis using a cellulase activity level of 2 filter paper units (FPU)/mL (20 FPU/g substrate). In the hydrolysis of two types of industrial cellulosic wastes, the enhancement effects were less pronounced. Parameters related to the IMTR design, such as the shape, dimensions, and mass of FMP, as well as the magnetic field strength, strongly affected the process of hydrolysis. Among various kinds of FMP tested, the most efficient were found to be cylindrical particles (0.25 x 4 mm). In general, the hydrolysis rate enhanced when the magnetic field strength increased from 26,000 to 64,000 A/m. An optimal FMP loading existed at each level of the field strength. Hydrolyzates obtained in the IMTR under the action ofTrichoderma reesei andPenicillium verruculosum cellulases contained glucose and cellobiose as soluble products, cellobiose being predominant (> 50%). Only when a high level of extra Β-glucosidase was added to the IMTR (10 CBU/mL), did glucose made up more than 90% of the products. Owing to extreme shear conditions in the IMTR, significant enzyme inactivation took place.     

电磁抗垢强化传热技术机理的实验研究

在自行设计建立的电磁抗垢、减垢实验装置上,对冷态工况下低频电磁抗垢、减垢技术机理进行了实验研究。冷态单次通过、循环实验和高倍扫描电镜结果表明,低频电磁能使污垢晶体的结构发生明显变化并有抑制污垢晶体尺寸长大的作用。     

Cerenkov自由电子激光辐射条件β~2ε_r＞1的确定

本文从麦克斯韦方程组和动量、能量守恒定律两个不同方来阐述β２εｒ＞１是Ｃｅｒｅｎｋｏｖ自由电子激光辐射的必要条件。