甘蓝夜蛾性信息素的合成

以四氢康醇为原料合成了甘蓝夜蛾的性信息系组分顺及反－１１－十六碳稀基乙酸酯。     

Computational study on 1,1,3,3-tetramethylguanidine-catalyzed cyanosilylation mechanism of hypnone

The reaction mechanism of cyanosilylation of hypnone catalyzed by 1,1,3,3-tetramethylguanidine (TMG) was investigated using the density functional theory at the Becke three-parameter hybrid functional combined with Lee–Yang–Parr correlation functional (B3LYP)/6-31G(d), B3LYP/6-31G(d, p) and B3LYP/6-311++G(d, p) levels. The results show that the title reaction occurs through two processes, the formation of the intermediate five through the interaction of TMG with trimethylsilyl cyanide (TMSCN) and the reaction between the intermediate five and hypnone. The formation of intermediate five controls the whole reaction with a Gibbs free energy barrier of 31.84 kcal/mol. In addition, the results indicate that the catalyst TMG significantly promotes the title reaction and changes the mechanism. The results are in reasonable agreement with the experimental observations. Our results reveal that the overall reaction is stepwise and exoergonic in solvent-free conditions at room temperature.     

Molecular solution to the optimal linear arrangement problem based on DNA computation

Due to massive parallelism, enormous memory storage and very low energy consumption, biomolecular operations have been suggested to solve various NP-hard problems that are beyond the capability of the fastest known digital computer. The optimal linear arrangement (OLA) problem is a well-known NP-hard combinatorial optimization problem. Based on a DNA computational model, this paper describes a novel algorithm for the OLA problem, which is executed in O(n ³log₂ n) DNA operations on tubes of (nK + n + m + L + 1)-bits DNA strands, where and . With the advance in molecular biology techniques, this algorithm may be of practical utility.     

Colloidal nanoparticles of a europium complex with enhanced luminescent properties

We report an alternative approach, that is, forming Eu(tta)3dpbt (dpbt = 2-( N, N-diethylanilin-4-yl)-4,6-bis(3,5-dimethylpyrazol-1-yl)-1,3,5-triazine, tta = thenoyltrifluoroacetonato) nanoparticles in water/methanol mixtures, to satisfy the combined requirements of good dispersibility in water solutions and efficient long-wavelength sensitization for Eu (III) complexes to be used in biological applications. The size of Eu(tta)3dpbt colloidal particles with very high luminescent capabilities can be modulated to some extent by changing the preparation conditions. The optical excitation window for the Eu (III) luminescence of Eu(tta)3dpbt nanoparticles, extending up to 475 nm, is wider than that of Eu(tta)3dpbt molecules dissolved in toluene. This is the first example for obviously extending the sensitization window of luminescent lanthanide materials to the long-wavelength region by forming nanoparticles of a lanthanide complex. Quantum yields of Eu (III) luminescence of the prepared Eu(tta)3dpbt colloidal particles, with an average diameter of 33.1 nm, are 0.27, 0.27, 0.24, 0.19, 0.14, and 0.01 upon excitation at 402, 420, 430, 440, 450, and 475 nm, respectively. The Eu(tta)3dpbt nanoparticles exhibited excellent two-photon sensitization performance with a highest delta Phi value of 3.2 x 10(5) GM (1 GM = 10(-50) cm4 s photo(-1) particle(-1)) at the excitation wavelength of 832 nm, which is about 7 times higher than the highest value reported for the CdSe/ZnS core-shell quantum dots. The favorable luminescent properties and the good dispersibility in water solutions of the Eu(tta)3dpbt nanoparticles are very promising for the development of new luminescent nanoprobes for bioanalysis.     

Highly Oxidative-Resistant Cyano-Functionalized Lithium Borate Salt for Enhanced Cycling Performance of Practical Lithium-Ion Batteries

Lithium difluoro(oxalato) borate (LiDFOB) has been widely investigated in lithium-ion batteries (LIBs) owing to its advantageous thermal stability and excellent aluminum passivation property. However, LiDFOB tends to suffer from severe decomposition and generate a lot of gas species (e.g., CO₂). Herein, a novel cyano-functionalized lithium borate salt, namely lithium difluoro(1,2-dihydroxyethane-1,1,2,2-tetracarbonitrile) borate (LiDFTCB), is innovatively synthesized as a highly oxidative-resistant salt to alleviate above dilemma. It is revealed that the LiDFTCB-based electrolyte enables LiCoO₂/graphite cells with superior capacity retention at both room and elevated temperatures (e.g., 80 % after 600 cycles) with barely any CO₂ gas evolution. Systematic studies reveal that LiDFTCB tends to form thin and robust interfacial layers at both electrodes. This work emphasizes the crucial role of cyano-functionalized anions in improving cycle lifespan and safety of practical LIBs.     

利用ADO对象动态创建数据库和表

阐述了在VB程序中利用ADO对象动态创建数据库和数据表的方法,这些方法在开发VB数据库应用程序中很有实用价值,可以提高数据库程序灵活性。     

Propagation of computer virus under the influences of infected external computers and removable storage media

In reality, a portion of infected external computers could enter the Internet, and removable storage media could carry virus. To our knowledge, nearly all previous models describing the spread of computer virus ignore the combined impact of these two factors. In this paper, a new dynamical model is established based on these facts. A systematic analysis of the model is performed, and it is found that the unique (viral) equilibrium is globally asymptotically stable. Some simulation experiments are also made to justify the model. Finally, a result and some applicable measures for suppressing viral spread are suggested.     

A cationic water-soluble pillar[5]arene: synthesis and host-guest complexation with sodium 1-octanesulfonate

By the introduction of trimethylammonium groups at both upper and lower rims, a cationic water-soluble pillar[5]arene was prepared, which forms a stable 1 : 1 host-guest complex with sodium 1-octanesulfonate in water.     

pH-responsive assembly and disassembly of a supramolecular cryptand-based pseudorotaxane driven by π-π stacking interaction

Driven by π-π stacking interaction, a supramolecular cryptand-based [2]pseudorotaxane was formed and its formation was demonstrated to be pH-responsive.     

SU(3) spin-orbit coupled fermions in an optical lattice

We propose a scheme to realize the SU(3)spin-orbit coupled three-component fermions in an one-dimensional optical lattice.The topological properties of the single-particle Hamiltonian are studied by calculating the Berry phase,winding number and edge state.We also investigate the effects of the interaction on the ground-state topology of the system,and characterize the interaction-induced topological phase transitions,using a state-of-the-art density-matrix renormalization-group numerical method.Finally,we show the typical features of the emerging quantum phases,and map out the many-body phase diagram between the interaction and the Zeeman field.Our results establish a way for exploring novel quantum physics induced by the SOC with SU(N)symmetry.