Applying reticular synthesis to the design of Cu-based MOFs with mechanically interlocked linkers

The concept of“robust dynamics”describes the incorporation of mechanically interlocked molecules(MIMs)into metal-organic framework(MOF)materials such that large amplitude motions(e.g.,rotation or translation of a macrocycle)can occur inside the free volume pore of the MOF.To aid in the preparation of such materials,reticular synthesis was used herein to design rigid molecular building blocks with predetermined ordered structures starting from the well-known MOF NOTT-101.New linkers were synthesized that have a T-shape,based on a triphenylene tetra-carboxylate strut,and their incorporation into Cu(II)-based MOFs was investigated.The single-crystal structures of three new MOFs,UWCM-12(fof),β-UWCM-13(loz),UWCM-14(lil),with naked T-shaped linkers were determined;β-UWCM-13 is the first reported example of the loz topology.A fourth MOF,UWDM-14(lil)is analogous to UWCM-14(lil)but contains a[2]rotaxane linker.Variable-temperature,²H solid-state NMR was used to probe the dynamics of a 24-membered macrocycle threaded onto the MOF skeleton.     

Nickel phosphonate MOF as efficient water splitting photocatalyst

A novel microporous two-dimensional(2D)Ni-based phosphonate metal-organic framework(MOF;denoted as IEF-13)has been successfully synthesized by a simple and green hydrothermal method and fully characterized using a combination of experimental and computational techniques.Structure resolution by single-crystal X-ray diffraction reveals that IEF-13 crystallizes in the triclinic space group Pi having bi-octahedra nickel nodes and a photo/electroactive tritopic phosphonate ligand.Remarkably,this material exhibits coordinatively unsaturated nickel(II)sites,free-P0₃H₂and-P0₃H acidic groups,a C0₂accessible microporosity,and an exceptional thermal and chemical stability.Further,its in-deep optoelectronic characterization evidences a photoresponse suitable for photocatalysis.In this sense,the photocatalytic activity for challenging H₂generation and overall water splitting in absence of any co-catalyst using UV-Vis irradiation and simulated sunlight has been evaluated,constituting the first report for a phosphonate-MOF photocatalyst.IEF-13 is able to produce up to 2,200 fimol of H₂per gram using methanol as sacrificial agent,exhibiting stability,maintaining its crystal structure and allowing its recycling.Even more,170μmol of H₂per gram were produced using IEF-13 as photocatalyst in the absence of any co-catalyst for the overall water splitting,being this reaction limited by the 0₂reduction.The present work opens new avenues for further optimization of the photocatalytic activity in this type of multifunctional materials.     

基于新标准的俄罗斯釆金业职业风险评估

当前俄罗斯正在进行立法改革以实现治理体系现代化，其中改革的重点是国家管理体系中的劳动保护、工业安全和突发事件的应急处理。过去的立法体系侧重于对受伤员工提供健康补偿和医疗救护，而新的立法体系则以预防为主，以期通过建立完善的风险管理机制和运行规则，提高安全生产水平、普及安全文化教育，保障员工的生命安全。新标准强调企业必须进行职业风险评估，并将职业风险评估纳入企业工作管理体系。论文以采金业为例，选取伊尔库茨克州波戴波区金矿露天采场为研究案例，探讨了现代化职业风险评估的方法，明确了职业风险评估首先要进行危害鉴别，编制了风险源管理档案清单。采用实测员工风险因素的“记分法”和数学模拟“矩阵法”完成了伊尔库茨克州波戴波区金矿露天采场主要职业的风险评估。研究表明: 在钻井爆破作业场所，由碎石的喷射、粉尘的排放和噪声效应引起的危险为不可接受风险，通过实施安全生产制度（即遵守安全标准和技术要求、为工人提供防护装备）,可将高风险和不可接受风险化解为可接受风险；阐述了高风险职业，编制了风险手册，提出了改善工作条件的首要措施是消除影响爆破手和钻机操作员的有害因素，并为员工提供能更有效预防噪音和振动的个人防护用品。     

A large-grain-size thick-film polycrystalline diamond detector for x-ray detection

A diamond film with a size of 6 × 6 × 0.5 mm³ is fabricated by electron-assisted chemical vapor deposition. Raman spectrum analysis, x-ray diffraction and scanning electron microscope images confirm the high purity and large grain size, which is larger than 300 μm. Its resistivity is higher than ${10}^{12}\,{\rm{\Omega }}\cdot {\rm{cm}}.$ Interlaced-finger electrodes are imprinted onto the diamond film to develop an x-ray detector. Ohmic contact is confirmed by checking the linearity of its current–voltage curve. The dark current is lower than 0.1 nA under an electric field of 30 kV cm⁻¹. The time response is 220 ps. The sensitivity is about 125 mA W⁻¹ under a biasing voltage of 100 V. A good linear radiation dose rate is also confirmed. This diamond detector is used to measure x-ray on a Z-pinch, which has a double-layer 'nested tungsten wire array'. The pronounced peaks in the measured waveform clearly characterize the x-ray bursts, which proves the performance of this diamond detector.     

纸基底印刷无芯片RFID湿度传感器* .txt

摘要：提出了一种基于纸基底的喷墨印刷无芯片RFID湿度传感器，通过遗传算法与射频仿真软件HFSS相结合，对常规开口环谐振器结构进行分布式加载，得到目标频率为245 GHz的谐振特性良好的传感器模型；采用DMP3000型材料打印机，在不同纸基底上喷墨印刷银墨水制作传感器，以纸张本身的吸水性实现湿度传感；研究不同纸基底对湿度传感器感湿灵敏度和恢复度的影响。结果表明，柯达相纸传感器的灵敏度最高，高湿灵敏度可达到8 MHz%RH，双铜纸湿度传感器恢复度高且恢复时间短，仅为2 min；两种基底湿度传感器皆有较好的一致性、中长期稳定性，且湿敏特性在20℃～30℃范围内受温度影响较小。对纸基湿度传感器的感湿机理进行了分析，纸主要成分纤维素表面的羟基与吸附的水分子作用形成氢键，改变了基底的介电参数，传感器的湿敏特性与纸的成分和结构有关。 .txt     

Sustainable Production of Surfactants from Renewable Resources(Online First, Recommended Article)

Surfactants are important chemical products, serving as emulsifiers and interfacial modifiers in the household detergents, personal care products, paints and coatings, foods, cosmetics, and pharmaceuticals industries. This review focuses upon recent advances in research and development to improve the ecological sustainability of surfactants throughout their life cycle, including derivation from renewable resources, production using green manufacturing principles, and improved biocompatibility and biodegradability during their consumer use and disposal stages. Biobased surfactants, derived from vegetable oils, polysaccharides, proteins, phospholipids, and other renewable resources, currently comprise approximately 24% of the surfactant market, and this percentage is expected to increase, especially in Asia. The use of renewables is attractive to consumers because of reduced production of CO2, a greenhouse gas associated with climate change. Enzymes can greatly increase process sustainability, through reduced use of organic solvent, water, and energy, and reduced formation of by-products and waste products. Among the enzymes being investigated for surfactant synthesis, lipases are the most robust, due to their relatively high biocatalytic activity, operational stability and their ability to form or cleave ester, amide, and thioester bonds. For enzymes to be robust catalysts of surfactants, further research and development is needed to improve catalytic productivity, stability and reduce their purchase cost.     

Regulation effect of osteoblasts towards osteocytes by silk fibroin encapsulation

Herein, the rational design micromilieus involved silk fibroin (SF)-based materials have been used to encapsulate the osteoblasts, forming an extracellular coated shell on the cells, which exhibited the high potential to shift the regulation of osteoblasts to osteocytes by encapsulation cues. SF coating treated cells showed a change in cell morphology from osteoblasts-like to osteocytes-like shape compared with untreated ones. Moreover, the expression of alkaline phosphatase (ALP), collagen I (Col I) and osteocalcin (OCN) further indicated a potential approach for inducing osteoblasts regulation, which typically accelerates calcium deposition and cell calcification, presenting a key role for the SF encapsulation in controlling osteoblasts behavior. This discovery showed that SF-based cell encapsulation could be used for osteoblasts behavior regulation, which offers a great potential to modulate mammalian cells’ phenotype involving alternating surrounding cues.