An in vitro Study on Transition from NO-Hemoglobin to Methemoglobin： Oxygen Effect

The nitrosyl-hemoglobin (HbNO) is the carrier of nitric oxide (NO) which is the important messenger molecule displaying multiple physiologic and pathophysiologic roles. However it is still not clear for the fate of HbNO molecules during the venous-arterial transit. In this letter, the HbNO transition in vitro was studied by using the electron paramagnetic resonance (EPR) spectra. It was found that HbNO molecules were stable when oxygen did not exist in the system but not stable in aerobic conditions. The absorption spectra further revealed that the methemoglobin (metHb) was the product of HbNO in aerobic environment, showing that the HbNO changed to metHb when there were enough oxygen molecules in the system.     

三维结构极限上限分析的有限元方法

根据塑性上限定理，采用罚一对偶方法，解决了三维极限分析中的塑性不可压问题，建立了三维结构上限分析的有限元规划格式，给出了相应的优化迭代求解算法。克服了目标函数非线性非光滑所导致的数值计算困难，使迭代过程产生的极限载荷因子和相关速度场收敛于真解的上限。该方法已应用于带缺陷压力容器的数值极限分析中，计算实例表明该方法具有数值稳定性好、精度高、收敛快等优点，并具有较广的适用范围。     

铸造专业方向的综合实验改革

本文讨论了在当前高校深化教学改革的新形势下,单独设置综合实验课程的思路以及实施几点体会。实践表明了综合实验课程能提高学生的综合素质和培养创新意识。     

一族奇异摄动时滞方程的有限差分法

考虑一族奇异掇动时滞微分方程．基于奇异摄动时滞方程准确解的性质，在分片等矩的Shishkin型网格上构造了线性奇异摄动时滞方程的有限差分格式，证得数值结果是关于小参数一致收敛的．应用牛顿拟线性法求解非线性奇异摄动时滞方程．数值实验证实了理论结果的准确性，进而表明该理论估计是稳健的．     

Regulating Oxygen Configuration in Hierarchically Porous Carbon Nanosheets for High-Rate and Durable Na+ Storage

Surface oxygen functionalities (particularly C−O configuration) in carbon materials have negative influence on their electrical conductivity and Na⁺ storage performance. Herein, we propose a concept from surface chemistry to regulate the oxygen configuration in hierarchically porous carbon nanosheets (HPCNS). It is demonstrated that the C−O/C=O ratio in HPCNS reduces from 1.49 to 0.43 and its graphitization degree increases by increasing the carbonization temperature under a reduction atmosphere. Remarkably, such high graphitization degree and low C−O content of the HPCNS-800 are favorable for promoting its electron/ion transfer kinetics, thus endowing it with high-rate (323.6 mAh g⁻¹ at 0.05 A g⁻¹ and 138.5 mAh g⁻¹ at 20.0 A g⁻¹) and durable (96 % capacity retention over 5700 cycles at 10.0 A g⁻¹) Na⁺ storage performance. This work permits the optimization of heteroatom configurations in carbon for superior Na⁺ storage.     

硅单粒子位移损伤多尺度模拟研究

本文结合分子动力学方法和动力学蒙特卡罗方法, 研究了单个粒子入射硅引起的位移损伤缺陷的产生和演化过程; 基于Shockley-Read-Hall理论计算了单个粒子入射引起的位移损伤缺陷导致的泄漏电流增加及其演化过程, 比较了缺陷退火因子与泄漏电流退火因子之间的差异, 并将计算结果与实验值进行了对比. 结果表明, 计算泄漏电流时, 仅考虑一种缺陷的情况下缺陷退火因子与泄漏电流退火因子相同, 考虑两种缺陷类型情况下二者在数值上有所区别, 但缺陷退火因子仍能在一定程度上反映泄漏电流的退火行为. 分子动力学模拟中采用Stillinger-Weber势函数和Tersoff势函数时缺陷退火因子和泄漏电流退火因子与实验结果一致, 基于Stillinger-Weber势函数的计算结果与实验值更为接近.     

樟脑基苯甲酰胺类化合物的合成及生物活性研究

以天然樟脑为原料,经中间体樟脑肟和樟脑胺,以及樟脑胺与取代苯甲酰氯的N-酰化反应,合成得到9个樟脑基苯甲酰胺类化合物(3a～3i)。初步探索了合成条件,并通过FT IR、1H NMR、13C NMR、ESIMS和元素分析等多种手段对目标产物进行结构表征。生物活性测试表明,在50mg/L浓度下,所合成的化合物对5种植物病原菌均有一定的抑制作用,其中化合物3c(R=2-Cl)和3i(R=4-F)对苹果轮纹病菌的抑制率分别达97.5%和96.4%,化合物3i对小麦赤霉病菌的抑制率为95.7%。在100mg/L浓度下,化合物对油菜的胚根生长均显示良好的抑制活性,其中化合物3b(R=4-Cl)的抑制率达97.4%。     

近红外光谱快检技术在口岸安全监管领域的应用展望

近红外快速检测技术在全球范围内作为一项新兴的快速检测手段,已在农业、食品、饮料、石油、材料、制药、医学、动植物检疫及其工业化过程等领域得到了广泛应用。该文结合近红外光谱快速检测原理及其应用现状,针对口岸安全监管中的商品智能归类、材料成分快速鉴定、动植物产品快速检疫鉴定、商品装卸载过程的在线监测等需求,提出引入近红外光谱检测技术应用于口岸安全监管领域的设想,力求为实现口岸贸易安全与贸易便利化双重目标奠定科技基础,并给出了近红外在口岸安全监管研究方面的应用展望。     

Reversibly Switching the Charge State and Adsorption Location of A Single Potassium Atom on Ultrathin CuO Films

Potassium (K) cations are spontaneously formed upon thermal deposition of low‐coverage K onto an ultrathin CuO monolayer grown on Cu(110) and they were explored by low‐temperature scanning tunneling microscopy (STM) and X‐ray photoemission spectroscopy. The formed K cations are highly immobile and thermally stable. The local work function around an individual K cation decreases by 1.5±0.3 eV, and a charging zone underneath it is established within about 1.0 nm. The cationic and neutral states of the K atom are switchable upon application of an STM bias voltage pulse, which is simultaneously accompanied by an adsorption site relocation.