porous

摘要： Bioinspired micro‐/nano‐motors are artificial micro‐/nano‐machines that can convert various forms of energy to propel their movement[1].For example,the motion of some of these micromachines can be precisely controlled by application of external physical stimuli including magnetic,electric and acoustic fields[2,3].Inspired by the study of microorganisms,researchers have been exploring also the use of available chemical energy from the local environment to trigger and sustain self‐propulsion[4].Within this research direction,Metal‐organic frameworks(MOFs)—a class of extended materials synthesized via a modular approach from inorganic(metal clusters or ions)and organic linkers[5]—offer excellent opportunities for the design and synthesis of self‐propelled micromotors.MOFs typically possess ultra‐high surface areas that allow facile access to densely populated catalytically active sites imbedded within their pore networks.Through careful design these catalytic sites can be exploited to convert chemical energy into kinetic energy resulting in self‐propulsion of the MOF crystal[6].In addition,rigidity,density,crystalline pore organization and pore size of MOFs can be optimized to carry out a swimming‐type motion[7].

摘要： Preparation of Si_(3)N_(4)porous ceramics via foam-gelcasting combined catalytic nitridation/Han Lei,Li Xiaojian,Zhang Haijun//Naihuo Cailiao.-2021,55(5):395Abstract:Si_(3)N_(4)porous ceramics were fabricated by foam-gelcasting combined catalytic nitridation using high-purity silicon powders as the starting material and Fe(N_(3))_(3)·9H_(2)O as the catalyst and CTAB as the foaming agent.The effects of the nitriding temperature(1200,1250,1300 and 1350°C)and the catalyst addition(0,1%,3%and 5%,by mass)on the phase composition,microstructure and physical properties of the Si_(3)N_(4)porous ceramics were investigated.The results show that with 1%of Fe(N_(3))_(3)·9H_(2)O,the Si_(3)N_(4)porous specimen nitridized at 1300°C has 29.7 MPa of compressive strength and 55.1%of apparent porosity.The relatively high strength of the porous ceramics can be attributed to the highly catalytic effect of Fe(N_(3))_(3)·9H_(2)O,which promotes the growth of Si_(3)N_(4)whiskers inside the specimen and plays a positive role in the improvement of mechanical properties.

摘要： Bronze phase TiO_(2)[TiO_(2)(B)]has great research potential for sodium storage since it has a higher theoretical capacity and ion mobility compared with other phases of TiO_(2).In this case,preparing porous TiO_(2)(B)nanosheets,which can provide abundant sodium insertion channels,is the most effective way to improve transport kinetics.Here,we use the strong one-dimensional TiO_(2)nanowires as the matrix for stringing these nanosheets together through a simple solvothermal method to build a bunchy hierarchical structure[TiO_(2)(B)-BH],which has fast pseudocapacitance behavior,high structural stability,and effective ion/electron transport.With the superiorities of this structure design,TiO_(2)(B)-BH has a higher capacity(131 vs.70 mAh g^(−1)[TiO_(2)-NWs]at 0.5 C).And it is worth mentioning that the reversible capacity of up to 500 cycles can still be maintained at 85 mAh g^(−1)at a high rate of 10 C.Meanwhile,we also further analyzed the sodium storage mechanism through the ex-situ X-ray powder diffraction test,which proved the high structural stability of TiO_(2)(B)-BH in the process of sodiumization/de-sodiumization.This strategy of uniformly integrating nanosheets into a matrix can also be extended to preparing electrode material structures of other energy devices.

摘要： Design and preparation of dual-role anode materials with extraordinary performance for rechargeable Li/Na-ion batteries (LIBs/NIBs) remains highly challenging.Herein,three-dimensional (3D) pomegranate-like porous bimetallic NiCo_(2)Se_(4) spheres with N-doped carbon (termed as NC@NiCo_(2)Se_(4)) are synthesized by solvothermal method and annealing.Microstructure investigations reveal that the NC@NiCo_(2)Se_(4) spheres include nano-sized NiCo_(2)Se_(4) particles as inner core and NiCo_(2)Se_(4) with the modification of thin-walled N-doped carbon layer as inner/outer shell.The bimetallic NC@NiCo_(2)Se_(4) spheres possess synergistic interaction of Ni/Co atoms to enhance intrinsic conductivity and electrochemical activity,unique pomegranate-like structure with an inner void space and robust shell to mitigation volume expansion,and intimate contact of N-doped carbon layer to improve interface effect and accelerate conversion kinetics.As anode materials,the NC@NiCo_(2)Se_(4) exhibits superior lithium/sodium storage performances (1401.6 and 794.8 mA h g^(-1)at current density of 0.5 and 5 A g^(-1)after 500 cycles for LIBs as well as 433.9 mA h g^(-1)at 3 A g^(-1)after 1000 cycles and a high capability of 306.6 mA h g^(-1)at 20 A g^(-1)for NIBs).This work represents an impressive strategy for future research of bimetallic selenides as anode materials for advanced high-performance LIBs/NIBs.

摘要： Correction to:J.For.Res.https://doi.org/10.1007/s11676-020-01240-5 In the original publication of the article,there were errors in the fig 3 and fig 6.The corrected Figs.3 and 6 are given below:The original article has been corrected.

摘要： The physical factors of the extracellular matrix have a profound influence on the differentiation behavior of mesenchymal stem cells(MSCs).In this study,different proportions of hydroxyapatite(HAp)were mixed into a poly(ethylene glycol)/silk fibroin(PEG/SF)solution to prepare scaffolds with different stiffness for studying the osteogenic effect on rat BMSCs in a biophysical microenvironment in vitro and in vivo.The amount of HAp ranged from 25 mg to 100 mg,which allowed the stiffness increasing from(80.98±17.45)kPa to(190.51±3.02)kPa be controlled suggesting the elastic modulus of the scaffolds increased with increasing HAp.

摘要： The effect of viscosity depending exponentially on temperature on the onset of penetrative ferro-thermal-convection (FTC) in a saturated horizontal porous layer in the presence of vertical magnetic field is investigated. The bounding surface of the ferrofluid layer is considered to be rigid-rigid and insulated to temperature perturbations. The resulting eigenvalue problem is solved numerically using the Galerkin technique and also analytically by a regular perturbation technique with wave number as a perturbation parameter. The analytical and numerical results are found to be concurrence. The characteristics of stability of the system are strongly dependent on the viscosity parameter B. The effect of B on the onset of ferroconvection in a porous layer is dual in nature depending on the choices of physical parameters and a sublayer starts to form at higher values of B. Whereas, increase in magnetic number M1 and the Darcy number Da is to advance the onset of ferroconvection in a porous layer. The nonlinearity of fluid magnetization M3?is found to have no influence on the onset of ferroconvection.

摘要： The present work reports the synthesis and application of sulfur doped into porous activated carbon for removing elemental mercury from natural gas using a bench-scale fixed-bed reactor. A series of experiments were carried out to investigate the optimization of Hg0 capture. Furthermore, our experimental results about optimum conditions to remove Hg0 were 1:10 of sulfur to activated carbon impregnation ratio, 350°C of impregnation temperature, and 3 hours of impregnation time. This research showed that the prepared adsorbents were capable to remove remarkable amount of Hg0 (23.615 mg/g) at high adsorption efficiency. This study may serve as reference on natural gas power plants for the removal of Hg0 using the same conditions.

摘要： The purpose of the present research is the different morphologies production of crystalline and amorphous-silica powder. It’s a basic material for many pharmaceutical and environmental applications as well. And, it’s produced using the combination of the alkali chemical etching process and the ultra-sonication technique. The critical preparation conditions are KOH concentration (weight %) and the sonication time (hour). The paper presents the chemical mechanism of the silica particle formation as well as the different morphology. The results show the formation of crystalline and amorphous-porous-silica particles in the micrometer range with the porous order network that has pore sizes range in micrometer too. This synthetic uses commercial silicon, which could be useful for large-scale production. Also, the nano-sphere and nano-cubic shapes of silica powder are formed starting by commercial silicon powder.

摘要： Sn/Sb based alloy anodes have attracted considerable interest as electrodes for next-generation high performance Li-ion batteries (LIBs) owing to their high theoretical capacities. And fabricate porous structure is an effective way to improve materials’ cycling performance. Here, we developed nanoporous SnSb alloy ribbon (NP-SnSb) through a melt-spinning/chemical-etching process and took it as electrode of LIB directly. Being of self-supported and binder free, the NP-SnSb shows a total outperformance over its nonporous counterparts both in cycling performance and kinetic characteristic. Besides, considering the melt-spinning/chemical-etching synthetic process is high-through-put and simple, the ribbon kind of alloy anodes have strong potential application for LIBs research.

摘要： The behavior of Cu-Ni-Ag-Al alloy used as anode for aluminum electrolysis was directly visualized in a two-compartment see-through cell during electrolysis, and its performances were tested at 850°C in acidic electrolyte molten salts consisting of NaF-AlF3-8%NaCl-5%CaF2-4%Al203 for 40h in a laboratory cell. The results show that nascent oxygen oxidized the anodic surface to form oxide film at the beginning of electrolysis. Post electrolysis, X-ray diffraction analysis of alloy surface show oxide film on the anodic surface consist of CuO, NiO, A12O3, CuAl2O4 and NiAl2O4. However, SEM photo shows the oxide film is porous, loose and easy to fall into electrolyte and contaminate aluminum. The corrosion mechanism of metal anodes is analyzed in this paper.