Loosely coordinating diluted highly concentrated electrolyte toward -60℃ Li metal batteries

Lithium metal batteries(LMBs) promise energy density over 400 Wh kg^(-1).However,they suffer severe electrochemical performance deterioration at sub-zero temperatures.Such failure behavior highly correlates to inferior lithium metal anode(LMA) compatibility and sluggish Li^(+) desolvation.Here,we demonstrate that cyclopentylmethyl ether(CPME) based diluted high-concentration electrolyte(DHCE)enables-60℃ LMBs operation.By leveraging the loose coordination between Li^(+) and CPME,such developed electrolyte boosts the formation of ion clusters to derive anion-dominant interfacial chemistry for enhancing LMA compatibility and greatly accelerates Li^(+) desolvation kinetics.The resulting electrolyte demonstrates high Coulombic efficiencies(CE),providing over 99.5%,99.1%,98.5% and 95% at 25,-20,-40,and-60℃respectively.The assembled Li-S battery exhibits remarkable cyclic stability in-20,and-40℃ at 0.2 C charging and 0.5 C discharging.Even at-60℃,Li-S cell with this designed electrolyte retains> 70% of the initial capacity over 170 cycles.Besides,lithium metal coin cell and pouch cell with10 mg cm^(-2) high S cathode loading exhibit cycling stability at-20℃.This work offers an opportunity for rational designing electrolytes toward low temperature LMBs.

The Evolutionary History of Ore-forming Processes of Metallic Ore Deposits in Northern Guangxi

The northern Guangxi region is an important rare metal, rare earth metal and polymetallic metallogenic province. In the region there exist five metallogenic series and two metallogenic subseries, whose metallogenesis shows features of polycyclic spiral evolution throughout the geological history. As far as various cycles are concerned, mantle-derived ore substances were reduced while crust-derived ore substances increased from early to late timesfin the whole geological evolutionary history, mantle-derived substances decreased gradually while crust-derived ones increased. Meanwhile ore element associations became more and more varied. In terms of space, mineralization migrated from the old basement outwards, i.e. from west to east during the Precambrian, and from north to south during the Phanerozoic, and again from east to west during the Yanshanian.

Doping dependent metal to insulator transition in the(Bi,Pb)-2212 system:The evolution of structural and electronic properties with europium substitution

The present work investigates the effect of europium substitution on the （Bi, Pb）-2212 system in the concentration range 0.5 ≤ x ≤1.0. Phase analysis and lattice parameter calculations on the powder diffraction data and the elemental analysis of EDX show that the Eu atoms are successfully substituted into the （Bi, Pb）-2212 system. Resistivity measurements （64-300 K） reveal that the system exhibits superconductivity at x ≤ 0.5 and semiconductivity at x 〉 0.5. With the complete suppression of superconductivity which is known to be a quasi-two dimensional phenomenon in these materials, a metal to insulator transition takes place at x = 0.6 and the predominant conduction mechanism is found to be variable range hopping between localized states, resulting in macroscopic semiconducting behaviour. The results of electrical and structural properties of the doped （Bi, Pb）-2212 compounds suggest that the decrease of charge carrier concentration and the induced structural disorder are the more effective and dominant mechanisms in the origin of the metal to insulator transition and suppression of superconductivity due to Eu substitution at its Sr site.

Hydrothermal Syntheses and Crystal Structures of Six Complexes Constructed from 1,3,5-Benzenetricarboxylic Acid and 4'-(4-Pyridyl)-2,2':6',2''-terpyridine Mixed Ligands

Six new transition metal complexes, [Zn（HBTC）（PYTPY）]n·n PYTPY（1）, [Cu（HBTC）（PYTPY）]n·n PYTPY（2）, [Co（HBTC）（PYTPY）]n·n DMF（3）, [Mn（HBTC）（PYTPY）]n·n DMF（4）, [Cd（HBTC）（PYTPY）（H2O）]n·2nH2O（5）, and [Co（HBTC）（PYTPY）（H2O）2]（6）,（H3BTC = 1,3,5-benzenetricarboxylic acid, PYTPY = 4＇-（4-pyridyl）-2,2＇：6＇,2＇＇-terpyridine, DMF = N,N？-dimethylformamide）, have been synthesized and characterized by elemental analysis, IR and X-ray single-crystal diffraction. Complexes 1~5 all feature one-dimensional chain structures, and complex 6 exhibits a zero-dimensional structure. Complexes 1~5 present three-dimensional（3D） supramolecular frameworks via π-π stacking interactions, whenas 6 has also a 3D supramolecular structure assembled by hydrogen bonding. Meanwhile, complexes 1 ~ 6 exhibit the thermal stabilities and photoluminescent properties.

Dynamic fracture toughness of high strength metals under impact loading:increase or decrease

An elusive phenomenon is observed in previous investigations on dynamic fracture that the dynamic fracture toughness （DFT） of high strength metals always increases with the loading rate on the order of TPa.m1/2.s-1. For the purpose of verification, variation of DFT with the loading rate for two high strength steels commonly used in the aviation industry, 30CrMnSiA and 40Cr, is studied in this work. Results of the experiments are compared, which were conducted on the modified split Hopkinson pressure bar （SHPB） apparatus, with striker velocities ranging from 9.2 to 24.1 m/s and a constant value of 16.3 m/s for 30CrMnSiA and 40Cr, respectively. It is observed that for 30CrMnSiA, the crack tip loading rate increases with the increase of the striker velocity, while the fracture initiation time and the DFT simultaneously decrease. However, in the tests of 40Cr, there is also an increasing tendency of DFT, similar to other reports. Through an in-depth investigation on the relationship between the dynamic stress intensity factor （DSIF） and the loading rate, it is concluded that the generally increasing tendency in previous studies could be false, which is induced from a limited striker velocity domain and the errors existing in the experimental and numerical processes. To disclose the real dependency of DFT on the loading rate, experimentsneed to be performed in a comparatively large striker velocity range.

The effects of relative density of metal foams on the stresses and deformation of beam under bending

The exact analytic solution of the pure bending beam of metallic foams is given. The effects of relative density of the material on stresses and deformation are revealed with the Triantafillou and Gibson constitutive law （TG model） taken as the analysis basis. Several examples for individual foams are discussed, showing the importance of compressibility of the cellular materials. One of the objects of this study is to generalize Hill＇s solution for incompressible plasticity to the case of compressible plasticity, and a kinematics parameter is brought into the analysis so that the velocity field can be determined.

Magnetic and Transport Properties of La_(0.5-x)Nd_xBa_(0.5) CoO_3 Compounds

Substituting effects of Nd for La in La 0.5 Ba 0.5 CoO 3 compounds were studied systematically. The results show that Nd doping does not change the itinerant properties of the Co3d electrons. The molecular magnetic moment of the materials decreases monotonically with increasing Nd dopant. When Nd content x ≥0.45, a magnetic phase separation appears in the materials. When x ≤0.45, the Curie temperature decreases monotonically with increasing Nd dopant. This is due to the size effects of the rare earth ions. The electric resistance measurements show that in the studied temperature range, the conduction of the materials belongs to the thermo diffusion conduction below the Curie temperature, while it belongs to the variable range hopping conduction of polarons over the Curie temperature.

Characterization of Household Solid Waste in the Town of Abomey - Calavi in Benin

Identification of waste characteristics is an important step towards improving waste recovery. The aim of this research was to determine the physical and physico-chemical characteristics of waste of Abomey–Calavi city and to study the relationship between standard of living and average ratio of daily waste generated by each person. In this study the methodology used French standards to characterize particle size and typology of solid waste generated by the population of Calavi City in Benin, West Africa. According to home criteria, the study area was stratified into three distinct levels of standard of living called: high standing, medium standing and low standing;Waste from 60 households was weighed daily. The total waste produced by each household was collected seven (7) days a week, for a period of three weeks. Waste characterization was performed using ratio, size granulometry and typological composition. Physico- Chemical analysis including organic mater, pH, Total Organic Carbon, total Kjeldahl nitrogen and metal trace element were also performed. To better assess waste compostability, water extractable organic matter was quantified and qualitative identification was made with XAD8 and XAD4 resins. Results show that the amount of waste increases with the standard of living;the average ratio of daily waste generated is 0.89 kg day-1 person-1. Independently of the standard of living, fermentable compounds represent the largest proportion of waste materials (45%). Qualitative difference of waste content in organic matter is shown as a function of the population’s living standards. These results could be explained by a higher consumption of meat in the households with a higher standard of living, reflecting a greater proportion of transphilic (TPI), and hydrophilic (HPI) fractions. The C/N ratio is lower in the high standing households than in low ones. Metal trace element analysis showed a low but still significant pollution, whereas high iron and alu minum concentrations were found in all standings. In conclusion we propose a strategy for waste management in Abomey-Calavi based on sorting at the source to eliminate plastic waste and valorization of wastes via composting.

Rapid Expansion of Supercritical Solution of Poly (1,1,2,2- Tetrahy-droperfluorodecyl Acrylate)

Poly(1,1,2,2- tetrahydroperfluorodecyl acrylate) (poly (TA-N)) was synthesized in laboratory. The resulting morphology of rapid expansion of supercritical solution (RESS) sprays of poly(TA - N) was investigated. At apre - expansion temperature of 45℃), amorphous polymer was formed. At temperature around 60 ℃ to 80 ℃ , fibers were formed. Increase of temperature increasesparticle size slightly. At temperature of 105℃ , most of particles are spheres. The RESS is an attractive process. To apply the polymers desired for coating applications in an organic solvent - free process that is economically viable , and it will have implications for pollution prevention during polymer film

Two Fluorescent Complexes Assembled by Schiff Base 2-Methoxy-6-(phenyliminiomethyl) Phenolate Ligand

Two d10 metal complexes Zn（NCS）2（C14HI3NO2）2 （1） and [Cd（NO3）2（CI4HI3NO2）2]. 4H20 （2） assembled by 2-methoxy-6-（phenyliminiomethyl） phenolate ligand （C14H13NO2, HL） have been synthesized and characterized by elemental analysis, IR and TG The single-crystal X-ray diffraction studies demonstrated that complex 1 crystallizes in monoclinic, P21/c space group with a = 17.321（7）, b = 11.781（0）, c = 15.593（2） A, fl = 110.273（6）°, V = 2984.95 A3, Z = 4, C30H26N404SzZn, Mr = 636.04, F（000） = 1312, Dc = 1.415 g/cm3,μ（MoKa） = 1.004 mm＂1, the final R = 0.0403 and wR = 0.0900 for 21441 observed reflections with I 〉 20（/）. Complex 2 is of monoclinic system, space group C2/c with a = 16.7767（2）, b = 10.8989（2）, c = 17.4928（2） A, fl = 90.614（9）°, V= 3198.37 A3, Z = 4, C28H34N4O14Cd, Mr= 731.25, F（000） = 1528, Dc = 1.568 g＇cm^-3, μ（MoKa） = 0.757 mm-1, the final R = 0.0361 and wR = 0.0857 for 19811 observed reflections with I 〉 2σ（I）. The two complexes were formed by Schiff base 2-methoxy-6-（phenyliminiomethyl） phenolate ligand and formed a 3D supramolecular architecture by π-πstacking interactions. Moreover, the complexes are luminescent in the solid state. These observations indicate that the complexes are promising system for the development of potential photoactive materials.

美国铝业公司拉斐特厂新建铝-锂合金铸造车间

美国铝业公司（Alcoa）投资$90M在印第安纳州（IN）拉斐特（Lafayette）厂新建一个铝-锂合金铸造车间，面积10684m2，已于2012年5月破土动工，铸造供挤压与锻造用的圆锭及轧制用的扁锭，锭的生产能力大于20kt／a，这是全世界最大的铝-锂合金铸造项目。该公司发明的航天工业用的新一代铝-锂合金在铝展览会（Aluminum Excellence）获得了美国金属奖（American Metal Awards）。

Quantum Chemical Calculation on Preparation of YBa＿2Cu＿3O＿（7－δ） Powders by Hydrolysis of Metal Alkoxides

The structural characteristics of different alkoxides of Y. Ba and Cu are studied with quantum chemi-cal CNDO /2 calculations. The relative hydrolysis rate coefficients k_M of them are obtained according tothe relationship between frontier orbitals and organic chemical reactions. Based on the above results. properexperimental conditions for the preparation of homogeneous ultra-purity. submicro high-T_cYBa_2Cu_3O_(7-δ) superconducting powders are proposed.

Two New Supramolecular Hybrids Based on Bi-capped Keggin {PMo12V2O42} Clusters and Transition Metal Mixed-organic-ligand Complexes

Two supramolecular compounds [Cu（imz）2][Cu（phen）（imz）]2{[Cu（phen）]2[PMo6^VIMo6^VV2^IVO42]}（1） and [Co2（2,2＇-bpy）4（C2O4）][Co（2,2＇-bpy）3][PMo7^VIMo5^VV2^IVO42]（2,2＇-bpy）0.5.H2O（2）（phen=1,10＇-phenanthroline, imz= imidazole, 2,2＇-bpy=2.2＇-bipyridine） have been synthesized hydrothermally and characterized by elemental analyses, infrared spectrum, UV-Vis, X-ray photoelectron spectroscopy（XPS）, electron spin resonance（ESR） spectra, thermogravimetry analyses and single crystal X-ray diffraction analyses. Single-crystal X-ray diffraction analyses revealed that both the compounds represent the examples of compounds based on the bi-capped Keggin polyoxoanion {PMo12V2O42} and transition metal mixed-organic-ligand coordination complexes. Compound 1 consists of bi-capped Keggin polyoxoanion [PMo12V2O42]5 supported copper coordination groups, which are further interconnected with two types of copper complex fragments forming a 3D supramolecular framework via π-π stacking, C-H…O and N-H…-O hydrothermal bonding interactions. Compound 2 is a new hybrid consisted of polyoxoanion [PMo12V2O42]^4-, [Co2（2,2＇-bpy）4（C2O4）]^2＋ and [Co（2,2＇-bpy）3]^2＋. There are no direct interactions in compound 2, but the polyoxoanions together with two different cobalt complex groups construct a 3D supramolecular network through C-H…O hydrogen bonding interactions.

Rh-Catalyzed Formal[3+2]Cyclization for the Synthesis of 5-Aryl-2-(quinolin-2-yl)oxazoles and Its Applications in Metal lons Probes

Main observation and conclusion A facile and efficient strategy for the synthesis of 5-aryl-2-(quinolin-2-yl)oxazoles via rhodium-catalyzed formal[3+2]cyclization of 4-aryl-1-tosyl-1H-1,2,3-triazoles with quinoline-2-carbaldehydes has been described.The protocol employs mild conditions and offers good yields of diverse 2,5-aryloxazole derivatives with a broad reaction scope.It is amenable to gram-scale synthesis and easily transformation.Moreover,this 5-aryl-2-(quinolin-2-yl)oxazole skeleton is indeed a new fluorophore and its applications in metal ions probes are also investigated and showed fluorescent responses to mercury ion.

Supramolecular assembly of three d^(10) metal coordination polymers based on the naphthalene-1,8-dicarboxylate ligand:Syntheses,structures and luminescent properties

Three d10 tetranuclear complexes,Cd 4(1,8-nap) 4(2,2′-bipy) 4(H2O) 8·6H2O(1,8-nap=naphthalene-1,8-dicarboxylate and 2,2′bipy=2,2′-bipyridine)(1),Cd4(1,8-nap) 4(2,2′-bipy) 4(H2O) 8·6H2O(2) andZn4(1,8-nap) 4(2,2′-bipy) 4(H2O) 4·2H2O(3),have been synthesized under hydrothermal conditions and characterized by elemental analyses,IR and X-ray diffraction techniques. Complexes 1 and 2 are isomers showing one-dimensional ribbon-like structures connected by O-H···O hydrogen bonds,and the one-dimensional ribbons are further linked into the three-dimensional network by π-πstacking.In complex 3,the intramolecular O-H···O hydrogen bonds just exist in the inner of the single molecule ring to consolidate its structure,and the single molecules are further linked into a two-dimensional layer structure by the π-πstacking interactions.The luminescent properties reveal that all the complexes display luminescent properties in the violet region.

An experimental study on grinding of Zr-based bulk metallic glass

There are limited studies in the literature about machinability of bulk metallic glass （BMG）. As a novel and promising structural material, BMG material machining characteristics need to be verified before its utilization. In this paper, the effects of cutting speed, feed rate, depth of cut, abrasive particle size/type on the BMG grinding in dry conditions were experimentally investigated. The experimental evaluations were carried out using cubic boron nitride （CBN） and A1203 cup wheel grinding tools. The parameters were evaluated along with the results of cutting force, temperature and surface roughness measurements, X-ray, scanning electron microscope （SEM） and surface roughness analyse. The results demonstrated that the grinding forces reduced with the increasing cutting speed as specific grinding energy increased. The effect of feed rate was opposite to the cutting speed effect, and increasing feed rate caused higher grinding forces and substantially lower specific energy. Some voids like cracks parallel to the grinding direction were observed at the edge of the grinding tracks. The present investigations on ground surface and grinding chips morphologies showed that material removal and surface formation of the BMG were mainly due to the ductile chip formation and ploughing as well as brittle fracture of some particles from the edge of the tracks. The roughness values obtained with the CBN wheels were found to be acceptable for the grinding operation of the structural materials and were in the rangeof 0.34-0.58 lam. This study also demonstrates that con- ventional A1203 wheel is not suitable for grinding of the BMG in dry conditions.

Cluster Chemistry with(Pseudo-)Tetrahedra Involving Group 13-15(Semi-)Metal Atoms

Compounds containing(pseudo-)tetrahedral main group(semi-)metal units are fundamentally important in three aspects.First,they provide new strategies for the stabilization of tetrahedral units,such as Pn_(4)(Pn=P,As)and their isoelectronic analogs,in the coordination sphere of d-/f-block metal atoms.Second,they serve as first-step models for the activation of tetrahedral molecules.Third,they are starting materials for subsequent transformations toward larger clusters or materials.Partial or full isoelectronic replacement of the pnictogen atoms in P4 or As_(4) results in a variety of(pseudo-)tetrahedral anions,Tt_(4)^(4−)(Tt=Si,Ge,Sn,Si/Ge),(Ge_(3)Pn)^(3−)(Pn=P,As;formed in situ),(Tt_(2)Pn_(2))^(2−)(Tt/Pn=Ge/P,Ge/As,Sn/Sb,Sn/Bi,Pb/Sb,Pb/Bi),or(TrBi_(3))^(2−)(Tr=Ga,In,Tl),and also cations,(P3Ch)+(Ch=S,Se,Te).The anions have proven to be excellent starting materials and building blocks for multinary clusters in the context of Zintl chemistry.Such compounds,which push forward the boundary of intriguing P4 chemistry,have never been thoroughly summarized before.In this minireview,we introduce all known intact(pseudo-)tetrahedral group 13–15 units,as well as the coordination compounds based on them,along with two new missing links,[Au(η^(2-)Tt_(2)Bi_(2))_(2)]^(3−)(Tt=Sn,Pb).

Boosting CO_(2) electroreduction performance over fullerene-modified MOF-545-Co promoted by π –π interaction

Metal-organic frameworks(MOFs) have showed high promise in CO_(2)-electroreduction, yet their generally insufficient conductivity or low electron-transfer efficiency have largely restricted the wide-spread applications. Herein, fullerene molecules(i.e., C60and C70) have been successfully introduced into the pore-channels of a Co-porphyrin based MOF through a facile strategy. Thus-obtained hybrid materials present higher electron-transfer ability, enhanced CO_(2)adsorption-enthalpy and CO_(2)electroreduction activity. Notably, the charge transfer resistance(Rct) of C60@MOF-545-Co is almost 5 times lower of than that of MOF-545-Co, as well as 1.5 times increased for the CO_(2)adsorption enthalpy. As expect, the FECO of C60@MOF-545-Co(97.0%) is largely higher than MOF-545-Co(70.2%), C60@MOF-545(19.4%), C60(11.5%)and physical mixture(70.3%) and presented as one of the best CO_(2)electroreduction catalysts reported in H-cell system. The facile strategy would give rise to new insight into the exploration of powerful MOFbased hybrid materials in high-efficiency CO_(2)electroreduction.

Bifunctional Mo-doped FeCo–Se aerogels catalysts with excellent OER and ORR activities for electro-Fenton process

Antibiotic pollution in aqueous solutions seriously endangers the natural environment and public health.In this work,Mo-doped transition metal FeCo–Se metal aerogels(MAs)were investigated as bifunctional catalysts for the removal of sulfamethazine(SMT)in solution.The optimal Mo_(0.3)Fe_(1)Co_(3)–Se catalyst can remove 97.7% of SMT within 60 min(SMT content:10 mg/L,current intensity:10 mA/cm 2).The unique porous cross-linked structure of aerogel confered the catalyst sufficient active sites and efficient mass transfer channels.For the anode,Mo_(0.3)Fe_(1)Co_(3)–Se MAs exhibits superior oxygen evolution reaction(OER)property,with an overpotential of only 235 mV(10 mA/cm 2).Compared with Fe_(1)Co_(3) MAs or Mo_(0.3)Fe_(1)Co_(3) MAs,density functional theory(DFT)demonstrated that the better catalytic capacity of Mo_(0.3)Fe_(1)Co_(3)–Se MAs is attributed to the doping of Mo species and selenization lowers the energy barrier for the*OOH to O_(2) step in the OER process.Excellent OER perfor-mance ensures the self-oxygenation in this system,avoiding the addition of air or oxygen in the traditional electro-Fenton process.For the cathode,Mo doping can lead to the lattice contraction and metallic character of CoSe_(2),which is beneficial to accelerate electron transfer.The adjacent Co active sites effectively adsorb*OOH and inhibit the breakage of the O–O bond.Rotating ring disk electrode(RRDE)test indicated that Mo_(0.3)Fe_(1)Co_(3)–Se MAs has an excellent 2e^(-)ORR activity with H_(2)O_(2) selectivity up to 88%,and the generated H_(2)O_(2) is activated by the adjacent Fe site through heterogeneous Fenton process to generate⋅OH.

Electrochemical Corrosion Behavior and Mechanical Response of Selective Laser Melted Porous Metallic Biomaterials

The porous metallic biomaterials have attracted significant attention for implants because their lower young's modulus matches the human bones, which can eliminate the stress shielding effect and facilitate the growth of bone tissue cells. The porous metallic biomaterials fabricated by selective laser melting (SLM) have broad prospects, but the surface of the SLM-built porous structure has been severely adhered with unmelted powders, which affects the forming accuracy and surface quality. The porous metallic biomaterials face the corrosion problem of complex body fluid environments during service, so their corrosion resistance in the human body is extremely important. The surface quality will affect the corrosion resistance of the porous metallic biomaterials. Therefore, it is necessary to study the effect of post-treatment on the corrosion resistance of SLMed samples. In this work, the mechanical response and the electrochemical corrosion behavior in simulated body fluid of diamond and pentamode metamaterials Ti-6Al-4V alloy fabricated by SLM before and after sandblasting were studied. After sandblasting, the mechanical properties of the two porous metallic biomaterials were slightly improved, and the self-corrosion potential and pitting potential were more negative;meanwhile, the self-corrosion current density and passive current density increased, indicating that its corrosion performance decreased, and the passive film stability of sandblasted samples got worse.