一类非线性规划问题的等价性证明

给出了非线性规划问题中目标函数单调变换前后的一个等价性证明.     

Hα Emission Imaging during Supersonic Molecular Beam Injection by CCD Photograph

There are several fuelling methods for tokamak plasma： pellet injection （PI）, gas puffing （GP）, neutral beam injection （NBI） and supersonic molecular beam injection （SMBI） .SMBI has been created in the Southwestern Institute of Physics, China.     

Hydrogen peroxide-generating nanomedicine for enhanced chemodynamic therapy

Chemodynamic therapy(CDT) is an emerging endogenous stimulation activated tumor treatment approach that exploiting iron-containing nanomedicine as catalyst to convert hydrogen peroxide(H_2O_2)into toxic hydroxyl radical(·OH) through Fenton reaction.Due to the unique characteristics(weak acidity and the high H_2O_2 level) of the tumor microenvironment,CDT has advantages of high selectivity and low side effect.However,as an important substrate of Fenton reaction,the endogenous H_2O_2 in tumor is still insufficient,which may be an important factor limiting the efficacy of CDT.In order to optimize CDT,various H_2O_2-generating nanomedicines that can promote the production of H_2O_2 in tumor have been designed and developed for enhanced CDT.In this review,we summarize recently developed nanomedicines based on catalytic enzymes,nanozymes,drugs,metal peroxides and bacteria.Finally,the challenges and possible development directions for further enhancing CDT are prospected.     

Boosting the synthesis of value-added aromatics directly from syngas via a Cr2O3 and Ga doped zeolite capsule catalyst

Even though the transformation of syngas into aromatics has been realized via a methanol-mediated tandem process, the low product yield is still the bottleneck, limiting the industrial application of this technology. Herein, a tailor-made zeolite capsule catalyst with Ga doping and SiO₂ coating was combined with the methanol synthesis catalyst Cr₂O₃ to boost the synthesis of value-added aromatics, especially para-xylene, from syngas. Multiple characterization studies, control experiments, and density functional theory (DFT) calculation results clarified that Ga doped zeolites with strong CO adsorption capability facilitated the transformation of the reaction intermediate methanol by optimizing the first C–C coupling step under a high-pressure CO atmosphere, thereby driving the reaction forward for aromatics synthesis. This work not only reveals the synergistic catalytic network in the tandem process but also sheds new light on principles for the rational design of a catalyst in terms of oriented conversion of syngas.

The single-pass conversion of syngas into para-xylene was realized using a bifunctional catalyst Cr₂O₃/Ga-ZSM-5@SiO₂. The Ga species facilitates the methanol consumption process by C–C coupling optimization, enhancing the yield of the target aromatics.     

高层建筑外附雨篷的表面风压和气动力系数

采用风洞试验方法研究高层建筑外附雨篷的风压特征,分析风压系数、风压相关性、非高斯性和整体升力系数随风向角的变化,给出围护结构的设计风压,最后研究倾角和出挑长度对整体力系数的影响. 研究发现,高层建筑外附雨篷上表面风压系数在正迎风时最大值接近1.4,系气流受到后方高层建筑的阻挡下翻导致;上、下表面的最大整体压力系数出现正迎风情况,最大值分别为1.24和0.76;上、下表面的最大整体升力系数出现侧风面,最大值分别为1.13和1.01;上下叠加后测点风压的非高斯性比单表面增强;上表面和下表面的升力系数在0°~70°风向呈现高斯分布,在80°~180°风向呈现较强的非高斯分布;高层建筑外附雨篷上表面的极值正压大于下表面;雨篷整体升力系数按照倾角-10°、0°、10°依次递增.     

镦粗工艺理论与技术的进展

提出了普通平板间镦粗圆柱体高径比Ｈ／Ｄ〉１时刚塑性力学模型的拉应力理论和高径比Ｈ／Ｄ〈１的静水应力力学模型的剪应力理论,前者打破了传统工程塑性力学中所阐述的镦粗体内部总处于三向压应力之说,后者圆满地解释了大型饼类锻件中常出现的“夹馅饼”缺陷问题,平板镦粗所理论已被定性物理模拟和定量数值模拟,广义滑移线解,力学分块法和生产解剖试验所证实,在该新理论基础上,进一步提出方柱镦粗的两个新力学模型,锥形板镦     

凹面体散射近场的有限元—人工透射边界解法

采用有限元－人工透射边界法求出平面波在无限长圆柱上的散射近场,并与解析解进行比较,进而对几种凹面体电磁波散射近场求解。实际应用表明该方法具有图象清楚,过程简单,适应性强等优点,可有效解决分层介质,非均匀介质中各种复杂的散射问题,亦可广泛应用于声波等其他类波的散射问题。     

Determination of trace silver by solid substrate room temperature phosphorescence quenching method based on lead carboxymethyl cellulose particles (Pb(CMC)2) containing luminescent salicyl fluorenes molecules

Luminescent particles of lead carboxymethyl cellulose (Pb(CMC)2) containing salicyl fluorones (THBF), Pb(CMC)2-THBF were synthesized by the sol-gel method, using sodium carboxymethyl cellulose (NaCMC) as precursor and Pb2+ as precipitant. Pb(CMC)2-THBF can emit the intense and stable solid substrate room temperature phosphorescence (SS-RTP) on filter paper. And EDTA can chelate Pb2+ in Pb(CMC)2-THBF, causing it to decompose into aqueous soluble components PbY2-, CMC- and THBF, which can react with Ag+ to form Ag(CMC)2-THBF, causing the decrease of phosphorescence intensity. Based on the facts above, a new method for the determination of trace silver by SS-RTP quenching method was established. The linear range of this method is 8.0-40.0 fg spot(-1) (20.0-100.0 pg ml(-1)), with a detection limit (LD) of 2.2 fg spot(-1) (corresponding to a concentration range of 5.5 x 10(-13) g ml(-1)), and the regression equation of working curve is DeltaI(p) = 12.56 + 0.5527C(Ag+) (fg spot(-1), 0.4 microl spot(-1)), n = 8, r = 0.9992. This method has been applied to the determination of trace silver in human hair and tea sample with satisfactory results. The mechanism of SS-RTP emission is also discussed.     

Importance of van der Waals Interactions in QM/MM Simulations

The importance of accurately treating van der Waals interactions between the quantum mechanical (QM) and molecular mechanical (MM) atoms in hybrid QM/MM simulations has been investigated systematically. First, a set of van der Waals (vdW) parameters was optimized for an approximate density functional method, the self-consistent charge-tight binding density functional (SCC-DFTB) approach, based on small hydrogen-bonding clusters. The sensitivity of condensed phase observables to the SCC-DFTB vdW parameters was then quantitatively investigated by SCC-DFTB/MM simulations of several model systems using the optimized set and two sets of extreme vdW parameters selected from the CHARMM22 forcefield. The model systems include a model FAD molecule in solution and a solvated enediolate, and the properties studied include the radial distribution functions of water molecules around the solute (model FAD and enediolate), the reduction potential of the model FAD and the potential of mean force for an intramolecular proton transfer in the enediolate. Although there are noticeable differences between parameter sets for gas-phase clusters and solvent structures around the solute, thermodynamic quantities in the condensed phase (e.g., reduction potential and potential of mean force) were found to be less sensitive to the numerical values of vdW parameters. The differences between SCC-DFTB/MM results with the three vdW parameter sets for SCC-DFTB atoms were explained in terms of the effects of the parameter set on solvation. The current study has made it clear that efforts in improving the reliability of QM/MM methods for energetical properties in the condensed phase should focus on components other than van der Waals interactions between QM and MM atoms.     

A complete sequence and comparative analysis of a SARS-associated virus(Isolate BJ01)

Severe Acute Respiratory Syndrome (SARS) is a newly identified infectious disease[1—5]. The global outbreak of SARS has been threatening the health of people worldwide and has killed 353 people and infected more than 5462 in 27 countries, as reported by WHO on April 29, 2003 (http://www.who.int/csr/sarscountry/en). Although it has been recognized that a variant of virus from the family of coronavirus might be the candidate pathogen of SARS[1—5], its identity as the unique pathogen sti…