多材料3D打印技术制作用于毛细管电泳的非接触电导/激光诱导荧光二合一检测池

利用多材料3D打印技术研制了用于毛细管电泳(CE)的二合一检测池,实现了电容耦合非接触电导(C⁴D)与共聚焦激光诱导荧光(LIF)两种检测方法在毛细管柱上同一位置同时检测。3D打印的检测池采用了导电的复合聚乳酸(PLA)材料制作C⁴D的屏蔽层,采用普通的绝缘PLA材料支撑C⁴D金属管电极并隔离屏蔽层。两根金属管电极通过“打印-暂停-打印”的方式嵌入到检测池中,两电极被2 mm厚的导电屏蔽层隔开,在屏蔽层中有一直径为1 mm的圆形通孔用于LIF检测。该检测池与带流通式进样接口的自组装CE系统联用,用于同时检测无机离子和异硫氰酸荧光素(FITC)标记的氨基酸。研究优化了C⁴D激励信号频率与电泳缓冲液浓度,选用的电泳缓冲溶液为10 mmol/L 3-吗啉丙烷-1-磺酸(MOPS)与10 mmol/L二(2-羟乙基)亚氨基三(羟甲基)甲烷(Bis-Tris)的混合溶液,选用C⁴D激励频率为77 kHz。二合一检测池应用于内径为25 μm的毛细管时,C ⁴D对Na⁺、K⁺和Li⁺的检出限分别为2.2、2.0和2.6 μmol/L; LIF对荧光素和FITC的检出限分别为7.6和1.7 nmol/L。两种检测方法的相对标准偏差在0.3%至4.5%之间(n=3),工作曲线的相关系数r ²≥0.9904。采用3D打印技术可以在实验室内实现复杂结构的制作,降低了制作的成本,且便于方法的推广和改进。     

2-甲氧/乙氧羰基-4-氟苯基-1,5-苯并硫氮杂的合成、抑真菌活性及构效关系

以高活性的2-甲氧/乙氧羰基-4-(4-氟苯基)-1,5-苯并硫氮杂A和B为模型化合物,设计合成了11个含氟杂衍生物3a~3k,考察了它们对白色念珠菌和新生隐球菌的抑菌活性.研究结果表明,2-甲氧/乙氧羰基-4-(2-氟苯基)/(3-氟苯基)/(2,4-二氟苯基)-1,5-苯并硫氮杂3a,3b,3d~3f对新生隐球菌有很强的抑菌活性,3c的活性中等,而7位氯代杂3g~3k基本无活性;上述杂对白色念珠菌均无活性.在此基础上,进一步测试了高活性杂3a,3b,3d~3f对新生隐球菌的抑菌浓度梯度、最小抑菌浓度(MIC)和最小杀菌浓度(MFC),发现其MIC和MFC均远低于对照药氟康唑.为了考察杂3a~3f的药效基团,又设计合成了4类杂衍生物4a~4f,5a~5f,6a~6f和7a~7c,通过对其抑菌活性的评价,发现分子中2-甲氧/乙氧羰基和亚胺官能团对杂3a~3f的抑真菌(新生隐球菌)活性起关键作用,硫原子被氧原子或氮原子代替后原杂的活性降低.     

Effect of precompression on pressure-transmitting efficiency of pyrophyllite gaskets

Pyrophyllite is widely used both as a gasket material and as a pressure-transmitting medium, especially for a large-volume press. Its pressure-transmitting efficiency mainly depends on the following factors: geometry of anvil and pyrophyllite block, chemical composition, density and strength. For a long time, most studies have been devoted to the first two factors, whereas the third one has been studied less. In this work, we report that the pressure-transmitting efficiency of pyrophyllite is improved by precompressing. The results show that pyrophyllite was fully densified when the pressure reached about 1 GPa. The press load for Ba I–II transition in the cubic large-volume pressure cell is reduced more than 8×10⁵ N by using the densified pyrophyllite, compared with the unprecompressed pyrophyllite. Namely, the press-load utilization efficiency was improved above 15% when the precompressed pyrophyllite is used as a pressure-transmitting medium.     

[FeFe]‐Hydrogenase Mimetic Metallopolymers with Enhanced Catalytic Activity for Hydrogen Production in Water

Electrocatalytic [FeFe]‐hydrogenase mimics for the hydrogen evolution reaction (HER) generally suffer from low activity, high overpotential, aggregation, oxygen sensitivity, and low solubility in water. By using atom‐transfer radical polymerization (ATRP), a new class of [FeFe]‐metallopolymers with precise molar mass, defined composition, and low polydispersity, has been prepared. The synthetic methodology introduced here allows facile variation of polymer composition to optimize the [FeFe] solubility, activity, and long‐term chemical and aerobic stability. Water soluble functional metallopolymers facilitate electrocatalytic hydrogen production in neutral water with loadings as low as 2 ppm and operate at rates an order of magnitude faster than hydrogenases (2.5×10⁵ s^?1), and with low overpotential requirement. Furthermore, unlike the hydrogenases, these systems are insensitive to oxygen during catalysis, with turnover numbers on the order of 40 000 under both anaerobic and aerobic conditions.     

用石蜡作碳源在高温高压下合成金刚石

用石蜡作炭源，从原子分子转化的角度，选择适当的氧化剂、触媒和组装方式，在高温高压下合成出了０．３ｍｍ大小的金刚石。     

Eco-friendly chitosan@silver/plant fiber membranes for masks with thermal comfortability and self-sterilization

The surgical masks have been essential consumables for public in the COVID-19 pandemic. However, long-time wearing masks will make wearers feel uncomfortable and massive discarded non-biodegradable masks lead to a heavy burden on our environment. In this paper, we adopt degradable chitosan@silver (CS@Ag) core–shell fibers and plant fibers to prepare an eco-friendly mask with excellent thermal comfort, self-sterilization, and antiviral effects. The thermal network of CS@Ag core–shell fibers highly improves the in-plane thermal conductivity of masks, which is 4.45 times higher than that of commercial masks. Because of the electrical conductivity of Ag, the fabricated mask can be electrically heated to warm the wearer in a cold environment and disinfect COVID-19 facilely at room temperature. Meanwhile, the in-situ reduced silver nanoparticles (AgNPs) endow the mask with superior antibacterial properties. Therefore, this mask shows a great potential to address the urgent need for a thermally comfortable, antibacterial, antiviral, and eco-friendly mask.

Graphical abstract

     

Synthesis and Structure of Novel Dimethylcobalt(III) Complexes Containing Trimethylphosphine and Salicylaldiminato(N:O) Ligands

Dimethyl(salicylaldiminato[N:O])cobalt complexes [CoMe₂(2‐O‐C₆H₁R¹R² R³‐CH=NR⁴)L₂] (L=PMe₃) ( 1 ‐ 6 ) have been prepared through the reaction of [CoMe₃(PMe₃)₃] with the corresponding substituted salicylaldimine. The complexes were characterized with IR, ¹H NMR, ¹³C NMR, ³¹P NMR and elemental analyses. The X‐ray crystal structure of complex 1 shows an octahedral coordination of cobalt, with two equatorial cis‐methyl groups opposite to the planar N:O‐chelate ring.     

Domain configuration and dielectric properties of Ba0.6Sr0.4TiO3 thin films

The microstructure and electrical properties of Ba_0.6Sr_0.4TiO₃ thin films have been investigated. Nanometer-sized domains, ranging from 8 to about 30 nm, were observed by piezoresponse force microscopy (PFM). The critical size, below which only single domains exist, is found to be about 31 nm. The film exhibits ferroelectric behavior characterized by polarization hysteresis loop and capacitance-voltage curve.     

飞行器性能样机虚拟试验系统研究与实现

为实现航天飞行器研制中性能样机模型的充分利用,提出了飞行器性能样机虚拟试验系统的总体方案,通过试验基础数据库、试验数据管理、验证辅助工具、虚拟试验应用等子系统划分和工作流程设计,提供对虚拟试验的全流程支持。系统突破了试验数据对象化管理、试验流程建模等关键技术,并基于虚拟试验支撑平台VITA完成了相应系统实现,在多个飞行器研制过程中开展了典型应用。