摘要：Five polymer bonded explosives(PBXs)with the base explosive epsilon-CL-20(hexanitrohexaazaisowurtzi-tane),the most important high energy density compound(HEDC),and five polymer binders(Estane 5703,GAP,HTPB,PEG,and F_(2314))were *** dynamics(MD)method was employed to investigate their binding energies(E_(bind))< compatibility,safety,mechanical properties,and energetic *** information and rules were reported for choosing better binders and guiding formulation design of high energy density material(HEDM).According to the calculated binding energies,the ordering of compatibility and stability of the five PBXs was predicted as epsilon-CL-20/PEG < epsilon-CL-20/ Estane5703 ≈ epsilon-CL-20/GAP < epsilon-CL-20/HTPB < epsilon-CL-20/F_(2314).By pair correlation function g(r)analyses,hydrogen bonds and vdw are found to be the main interactions between the two *** elasticity and isotropy of PBXs based epsilon-CL-20 can be obviously improved more than pure epsilon-CL-20 *** is not by changing the molecular structures of epsilon-CL-20 for each binder to affect the *** safety and energetic properties of these PBXs are mainly influenced by the thermal capability(C_p^(deg))and density(p)of binders,respectively.

摘要：Substantial effort has been made to search for electrode materials of Na-ion batteries with high energy/power density. The application of S-saturated zigzag MoS2 nanoribbons （MoSzNRs） for Na-ion batteries has been explored through density function theory （DFT）. The theoretical maximum specific capacity reaches 386.4 mAh,g t via dou- ble-side and special edge adsorption mode. The electronic structure reveals that there exists charge transfer between Na and MoS2NRs. The diffusion barrier on MoS2NRs （0.17 eV） is much lower than that of bulk MoS2 （1.15 eV）, indicating an excellent diffusion kinetics, in addition, the S-edge in MoS2NRs plays a key role. Firstly, the Mo edge was half saturated by S, which helps to stabilize the MoS2NRs as well as offer more intercalation sites for Na. On the other hand, Na migrates much faster on the S edge route in MoS2NRs. Our computational results show that S-saturated MoSzNRs exhibit a great potential as electrode materials for Na-ion batteries with high performance.

摘要：Porous g-C_(3)N_(4)nanosheets(PCN)were prepared by the nickel-assisted one-step thermal polymerization ***(H2)which was produced by the reaction between nickel(Ni)foam and ammonia(NH3)defined the structure and properties of *** the formation of PCN,the participation of H2 not only enhanced the spacing between layers but also boosted the specific surface area that more active sites were ***,H2 promoted pores formation in the nanosheets,which was beneficial to the transfer of photons through lamellar structure and improved the absorption efficiency of visible ***,the obtained PCN possessed better Cr(Ⅵ)photocatalytic reduction efficiency than pure g-C_(3)N_(4).The reaction rate constant(k)of PCN(0.013 min-1)was approximately twice that of bare g-C_(3)N_(4)(0.007 min-1).Furthermore,the effects of original pH and concentration of Cr(Ⅵ)-containing solution on re moval efficiency of Cr(Ⅵ)were explored.A possible photocatalytic mecha nism was proposed based on the experiments of radical scavengers and photoelectrochemical characterizations.

摘要：Nanozymes, nanomaterials with enzyme-like characteristics,are emerging as novel artificial enzymes (Gao et al., 2007;Manea et al., 2004;Yan, 2018). They are superior to natural enzymes in many ways, such as higher stability, lower cost in preparation, and better robustness toward harsh environments (Wei and Wang, 2013).

摘要：A significant enhancement in the thermoelectric performance was observed for three-dimensional conducting aerogels,which were obtained from poly（3,4-ethylenedioxythiophene）：poly（4-styrenesulfonic）（PEDOTrPSS） and multiwalled carbon nanotubes（MWCNTs） suspensions by adding different concentrations of metallic silver（Ag）.It was found that the electrical conductivity and Seebeck coefficient could be simultaneously increased with the unique ***,the conducting aerogels have an ultralow thermal conductivity（0.06 W m^（-1） K^（-1） and a large Brunauer-Emmett-Teller surface area（228 m^2 g^（-1）.The highest figure of merit（zT） value in this study was 7.56×10^（-3） at room temperature upon the addition of 33.32 wt.%*** the zT value was too low,our work may provide new insights into the design and development of the thermoelectric material for *** investigation with PEDOTrPSS aerogels will be continued to get an economical,lightweight,and efficient polymer thermoelectric material.

摘要：Silicon-based material is one of the most promising substitutes of widely used graphite anodes for the next generation Li-ion batteries due to its high theoretical capacity,low working potential,environmental friendliness,and abundant natural ***,the huge volume expansion and serious interfacial side reactions during lithiation and delithiation progresses of the silicon anode are the key issues which impede their further practical *** designs of silicon nanostructures are effective ways to address these *** this progress report,we firstly highlight the fundamental scientific problems,and then focus on recent progresses in design,preparation,in-situ characterization methods and failure mechanism of nanostructured silicon anode for high capacity lithium *** also summarize the key lessons from the successes so far and offer perspectives and future challenges to promote the applications of silicon anode in practical lithium batteries.

摘要：Selective hydrodeoxygenation of lignin derivatives into aromatic compounds is a promising route for the upgrading of lignin *** carbide catalysts have exhibited excellent selectivity in hydrodeoxygenation reactions,while their structure-activity relationship is still in ***,a liquid-phase atomic layer deposition method was employed to synthesize W_(2)C/SiO_(2) catalysts with uniform and size-controllable W_(2)C *** gas-phase hydrodeoxygenation of lignin-derived m-cresol at 350℃,these W_(2)C/SiO_(2) catalysts showed superior toluene selectivities(>95%)regardless of the W_(2)C particle *** optimal W_(2)C particle size of~7 nm was obtained for achieving the highest W_(2)C-based hydrodeoxygenation *** contrast,the turnover rate per surface W site increased almost monotonously as the W_(2)C particle size increased within 0.7-15 nm,attributable to high-index planes appeared on the larger W_(2)C *** effects of m-cresol and H_(2),taken together with temperature-programmed desorption of probe molecules and theoretical treatments,further indicate that the W_(2)C surface is nearly saturated by adsorbed m-cresol or its derivates under the reaction condition and the H-addition of the C7H7*intermediate to form toluene,instead of the initial C-O cleavage in m-cresol,acts as the rate-determining step.A side-by-side comparison between W_(2)C(102)and W_(2)C(001)catalyst surfaces in theoretical simulations of m-cresol hydrodeoxygenation verifies that high-index planes can stabilize kinetically-relevant transition states more effectively than the low-index ones,as a result of more available less-coordinated active sites on the *** above findings bring new mechanistic insights into the site requirements of supported W_(2)C nanocatalysts,distinct from those metal-catalyzed hydrodeoxygenation of oxygenates.

摘要：The uranyl ion(UO22+) poses high risks to human health and the environment, hence its detection and monitoring is of utmost significance. However, the development of an ultra-sensitive, high-efficiency and convenient approach for on-site detection of UO22+ remains a challenge. Herein, a reliable and reusable surface-enhanced Raman spectroscopy(SERS)-based microfluidic biosensor was developed for rapid detection of UO22+ in real samples. The detection protocol involved the reaction of 5′-Rhodamine B(RhB)-labeled double-stranded DNA for UO22+-specific DNAzyme-cleavage reaction in a U-shaped microchannel. Then, the reaction products were delivered into three parallel samples for high-throughput tests by SERS biochips,where 3 D ZnO-Ag mesoporous nanosheet arrays(MNSs) were modified with a single-stranded DNA(ssDNA). The ssDNAwas sequence-complementary with the 5′-RhB-labeled cleaved-stranded DNA(csDNA) from the reaction products. By the hybridization of ssDNA and csDNA, the signal probe RhB was fixed close to the surface of the ZnO-Ag MNSs to enhance the Raman signal. The limit of detection for UO22+ with the microfluidic-SERS biosensor was 3.71×10-15 M. An over 20,000-fold selectivity towards UO22+ response was also achieved in the presence of 15 other metal ions. The high-throughput microfluidicSERS biosensor operated well for practical UO22+ detection, with excellent recoveries in contaminated river and tap water from95.2% to 106.3%(relative standard deviation(RSD)<6.0%, n=6). Although the SERS-based microfluidic biosensor developed in this study was deployed for the detection of UO22+, the reusable and high-efficiency system may be expanded to the detection of other analytes on-site.

摘要：Tuning the electronic properties of single atom catalysts(SACs)between the central metal and the neighboring surface atoms has emerged as an efficient strategy to boost catalytic efficiency and metal *** we describe a simple and efficient approach to create atomically dispersed palladium atoms supported over defect-containing porous ceria nanorod containing palladium up to 0.26 wt.%.The existence of singly dispersed palladium atoms is confirmed by spherical aberration correction electron microscopy and extended X-ray absorption fine structure *** catalyst shows excellent efficiency in hydrodehalogenation reactions at low H2 pressure under mild conditions,along with satisfactory recyclability and *** functional theory(DFT)calculations reveal that the high activity stems from the spatial isolation of palladium atoms and the modified electronic structure of palladium confined in defect-containing ceria *** work may lay the foundation for the facile creation of single atom catalysts within the synthetic community and shed light on the possibility for scale-up production.

摘要：Gas-involving electrochemical reactions,like oxygen reduction reaction (ORR),oxygen evolution reaction (OER),and hydrogen evolution reaction (HER),are critical processes for energy-saving,environment-friendly energy conversion and storage technologies which gain increasing *** development of according electrocatalysts is key to boost their electrocatalytic *** efforts have been put into the development of advanced electrocatalysts to overcome sluggish *** the other hand,the electrode interfaces-architecture construction plays an equally important role for practical applications because these imperative electrode reactions generally proceed at triple-phase interfaces of gas,liquid electrolyte,and solid electrocatalyst.A desirable architecture should facilitate the complicate reactions occur at the triple-phase interfaces,which including mass diffusion,surface reaction and electron *** this review,we will summarize some design principles and synthetic strategies for optimizing triple-phase interfaces of gas-involving electrocatalysis systematically,based on the electrode reaction process at the three-phase *** can be divided into three main optimization directions:exposure of active sites,promotion of mass diffusion and acceleration of electron ***,we especially highlight several remarkable works with comprehensive optimization about specific energy conversion devices,including metal-air batteries,fuel cells,and water-splitting devices are demonstrated with superb *** the last section,the perspectives and challenges in the future are proposed.