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Since thermally sprayed zinc and aluminum coatings were invented 100 years ago, they have realized extensive industrial applications for steel structure protection in a variety of fields for nearly 100 years and have been proven to be effective and reliable. However, it has seldom been reported in the ship industry in China since many workers worry about the risk of rapid corrosion, especially in harsh environments such as the South China Sea. In this paper, three kinds of arc-sprayed zinc aluminum coatings were tested to choose the best coating system for application on the research vessel Yongle by electrochemical behavior and a long-term atmospheric exposure experiment. The variation of the corrosion rate and the bonding strength was used to clarify the long-term protection performance. The results show that Zn15Al has the lowest corrosion (Rp larger than 2200 Ω·cm2) among the three kinds of coatings and has a bonding strength larger than 6.38 MPa after a 5 year test. The performance of the coatings in the South China Sea indicates that they can provide excellent protection for the hull above the waterline of the Yongle vessel in the 3 year test. It could be predicted that thermally sprayed zinc aluminum coating has vast application potential in the South China Sea due to its excellent anticorrosion performance.

Different calcination atmospheres of air, 50% oxygen (vs. N2) and pure oxygen have been used to prepare special LiNi0.8Co0.1Mn0.1O2 cathode materials to observe the influence of oxygen composition. To investigate the structure and electrochemical property of the samples using different oxygen compositions, X-ray diffraction (XRD), X-ray photoelectron spectroscopy (XPS), scanning electron microscopy (SEM), cycling performance tests and electrochemical impedance spectroscopy (EIS) were carried out. XRD, SEM, and XPS results show that the sample made using higher oxygen composition has less cation mixing and lower levels of Ni2+. However, both samples have almost the same oxygen environments on their surfaces as well as micro-morphology and size. The sample with a higher oxygen composition shows better electrochemical performance. Interestingly, the electrochemical performance of the sample made using 50% oxygen is similar to that made with pure oxygen and much better than the sample made with air. It has a specific capacity of 202.4 mAh g−1 at 0.1C and a capacity retention of 85.2% after 300 cycles at 1C, which may be meaningful for balancing cost and performance.

In this work, three types of fully dense aluminum-based (Al) coatings (pure Al, AA2219 and AA6061) were deposited on AZ31B magnesium (Mg) alloy by a recently developed in-situ micro-forging assisted cold spray process. The detailed microstructure, coating adhesion and corrosion protection performance were systematically investigated. Results show that the porosities of the pure Al, AA2219 and AA6061 coatings are as low as 0.34 ± 0.11%, 0.23 ± 0.09% and 0.24 ± 0.08%, respectively. Strong adhesion strength (83.6–91.5 MPa) was achieved for the Al-based coatings due to the in-situ micro-forging induced enhanced mechanical-interlocking between Al-based coating and the magnesium alloy substrate. The corrosion current density of the AZ31B Mg alloy decreases to 1.9–5.8 μA cm−2 from 312.8 μA cm−2 after coated with the Al-based coatings. The long-term corrosion tests further indicate that the Al-based coatings are not aqueous solution permeable during the entire 1000 h immersion, thus provided robust long-term corrosion protection of AZ31B Mg alloy substrate. Moreover, the difference in corrosion resistances among the three Al-based coatings was observed and was further explained based on their unique microstructures arising from the coating deposition process. The present in-situ micro-forging assisted cold spray process shows great potential for economical and effective corrosion protection of magnesium alloy and provides more freedom for industries to design and use magnesium alloy parts.

The microscopic surface plays a crucial impact on catalytic activity. Herein, the rough-surfaced chain-like palladium nanowires with many steps and inflections are successfully synthesized by a simple one-step reduction by sodium borohydride. The mechanism of bromide ions adsorbing and the oxygen etching to control the growth of chain-like nanowires is investigated. Furthermore, the effect of the pH values of system on the microscopic surface of palladium nanowires, especially on the roughness, is discussed in depth. The nanowires prepared at pH = 11 exhibit rougher surfaces with a diameter of 10–11 nm, and the relevant catalyst has higher electrochemical active area and excellent electrocatalytic performance for oxygen reduction reaction (ORR). Its half-wave potential in 0.5 mol L−1 H2SO4 solution is 80 mV more positive than Pd nanoparticles, slightly negative than Pt/C and the half-wave potential in 0.1 mol L−1 KOH solution is 50 mV more positive than the Pd nanoparticles, and is almost the same as Pt/C. The research result reported here will have important implications for designing palladium-based catalysts to increase their electrocatalytic ability.

We report an innovative strategy to prepare the porous N-doped graphene aerogel with an open structure and abundant defects by hydrothermal self-assembly of zeolitic imidazolate framework (ZIF)-8 and graphene oxide. The in-situ hydrothermal restructuring of ZIF-8 on graphene sheets plays a key role in the synthesis of the open structure and the uniform N-doping. The dissolution and restructuring of ZIF-8 on graphene oxide obviously suppress the stacking and reunion of graphene sheets to obtain the continuous macroporous structure. Moreover, the introduction of N and Zn creates the abundant N-doped sites and microporous structure. Its unique structure and composition improve the accessible surface area, the mass transfer diffusion, the dispersion and electronic structure of Pt nanoparticles, further resulting in the high catalytic performance of Pt-based catalyst for methanol oxidation reaction (MOR). Its MOR activity is about 1.8 times of commercial Pt/C, and its long cycling durability is improved by about 18.7% compared with commercial Pt/C. This work renders a promising method by utilizing ZIF-8 derivatives to synthesize the excellent N-doped carbon materials for electrochemical applications.

Al-0.05Ga-0.05Sn-0.05Pb-xMg alloys with different Mg content have been prepared. Electrochemical tests including constant current discharge test, current polarization test, electrochemical impedance spectroscopy (EIS) test, and Tafel test are performed. The surface states of the alloys after constant current discharge were analyzed by scanning electron microscopy (SEM) and energy disperse spectroscopy (EDS). X-ray diffraction (XRD) analysis was carried out. We find that different Mg contents have great influence on discharge performance of aluminum alloy anodes by changing the corrosion behavior. The SEM and XRD show that Mg can influence the distribution of corrosion and change the grain size to improve the discharge performance of aluminum anodes. Al-0.05Ga-0.05Sn-0.05Pb-0.1Mg shows the best electrochemical performance due to uniform corrosion and proper grain size. At 800 mA cm−2 constant current discharge, the potential of the aluminum anode can reach − 1.54 V (vs Hg/HgO), and the utilization ratio is over 98%.

Nitrogen-doped three-dimensional porous graphene frameworks (NGAs) are fabricated through a unique strategy of adopting the supramolecular assembly-assisted method with GO as building block, and supramolecular aggregate of self-assembled melamine and cyanuric acid as not only a “spacer” to suppress the re-stacking of graphene nanosheets but a self-sacrificial pore-forming agent as well as a nitrogen source leading to simultaneous N-doping. Supramolecular aggregates function as the structure-directing agent playing a vital role in generating the loose porous and free-stacking structure and guiding the formation of unique 3D architecture. The resulting metal-free NGA products possess high specific surface area, porous structure and free-stacking properties, and exhibit enhanced ORR performance in terms of positive half-wave potential which is only ∼43 mV lower than that of a commercial Pt/C, four-electron-transfer process, good durability and outstanding methanol poisoning tolerance. Besides, it also performs as a good support for Pt particles. Consequently, Pt/NGA catalyst displays impressive catalytic activity and stability towards efficient methanol electrooxidation reaction. This simple and robust synthetic strategy of 3D N-doped graphene has put forward a new prospect for rational synthesis of heteroatoms doped carbon materials for sustainable energy conversion applications.

Titanium nitride (TiN) as catalyst support has a very good application prospect due to its chemical stability, electrical conductivity and the metal-support interaction. But it is difficult to synthesize nano-TiN with the uniform dispersion by a simple method. This paper proposes a novel and easy strategy to address the problem. The mesoporous g-C3N4 has been synthesized and used as both nano-reactor and nitrogen source for the synthesis of nano-TiN evenly dispersed onto Vulcan XC-72. The uniform dispersion of nano-TiN is conducive to depositing and anchoring the PtRu nanoparticles, further increasing the long-time catalytic durability. Moreover, the electronic effect of TiN obviously improves the catalytic activity and the adsorbed CO tolerance ability of PtRu catalysts for methanol oxidation. Compared with the PtRu/C catalyst, the activity of PtRu/C-TiN for methanol oxidation has been increased by 47.3%. Meanwhile, its durability has been improved by 6.5% after 1000 cycles. In addition, this novel and easy method can be generalized to the synthesis of other nano-size nitrides. The applications of nano-size nitrides modified carbon black in other fields are also expected in the future.

For the first time, a supramolecular template-derived synthesis approach is reported to fabricate 1D nitrogen-doped hollow carbon tubes (h-NCTs) with a hierarchical micro/mesoporous structure. A melamine cyanurate supramolecular assembly is used as the tubular-structure guiding template and nitrogen source, endowing the obtained h-NCTs catalyst with proliferative catalytic active sites, a high surface area as well as a well-defined multiscale pore system. The sample prepared at 900 °C (h-NCT-900) displays an exceptional half-wave potential of 0.86 V versus RHE, which is one of the best values recorded in the literature for a metal-free electrocatalyst.

Three nickel (Ni) powders, i.e. gas-atomized spherical Ni (GA-Ni), carbonyl irregular Ni (C-Ni), and electrolytic dendritic porous Ni (E-Ni), were sprayed on magnesium alloys by an in-situ micro-forging assisted cold spray method. Although all deposited coatings present extremely low porosity, the C-Ni and E-Ni coatings reveal poorer inter-particle bonding than GA-Ni coating. Electrochemical tests reveal that the inter-particle gaps will act as fast pathways for the corrosive media to penetrate the coatings, thereby the GA-Ni coating with intimate inter-particle boundaries can isolate the corrosive media for 3000 h and the C-Ni and E-Ni coatings fail after

The three-dimensional (3D) hybrid aerogels built from graphene and polypyrrole-derived nitrogen-doped carbon nanotubes (G-NCNTs) are synthesized by facile hydrothermal and heat treatment process using graphite oxide (GO) and polypyrrole nanotubes (PNTs) as precursors. The 3D G-NCNTs hybrid aerogels, in which the NCNTs are dispersed homogeneously in the graphene sheets, are designed to efficiently support Pt nanoparticles. Comparing with 3D graphene (GA), the 3D G-NCNTs supported Pt-based catalyst possesses improved electrocatalysis activity and stability toward methanol oxidation reaction (MOR). The mass activity of Pt/G-NCNTs-1/2 catalyst is 0.74 A mg−1Pt, which is 1.4 times that of the Pt/GA catalyst (0.54 A mg−1Pt). In addition, the retention rate after 1000 cycles for Pt/G-NCNTs-1/2 catalyst is as high as 82.4%, obviously superior to 68.5% of Pt/GA catalyst. The enhanced electrochemical performance is ascribed to the synergistic effect of GA and NCNTs. The introduction of NCNTs can uniformly disperse and strongly anchor Pt nanoparticles due to the increase in nitrogen active sites. Moreover, the NCNTs introduced into GA may prevent the restacking of graphene sheets, and provide a large accessible surface area for better dispersing Pt nanoparticles and transporting reactants and products.

In this study, Zn-Ni composite coatings with different Ni contents were deposited on low-carbon steel using Low pressure cold spray (LPCS) method. The morphology, element distribution and phase compositions of powders and as-sprayed coatings were analyzed by using scanning electron microscopy, energy dispersive spectrometer and X-ray diffraction respectively. The corrosion protection mechanism of these composite coatings were investigated using electrochemical technique and their corrosion morphologies. The results show that Zn-Ni composite coatings exhibited a better sacrificial anodic protection and physical shielding effect, where the corrosion resistance of the coating with 10 wt% Ni in the feedstock was best. The corrosion products were mainly composed of Zinc hydroxide Zn(OH)2, basic zinc chloride hydrate ZnCl2·4Zn(OH)2·H2O, basic zinc carbonate hydrate Zn4·CO3(OH)6·H2O and the corrosion products is not mixed with alumina. The corrosion process mainly includes active dissolution of zinc, zinc cathodic protection, physical shielding caused by corrosion products.

Molybdenum dioxide (MoO2) has been adopted as an advanced auxiliary support material for its outstanding electrical properties to anchor metal nanoparticles (NPs). To overcome the drawback of MoO2 electronic conductivity, a novel hierarchical carbon coated molybdenum dioxide (MoO2@C) nanotube built from ultra-thin nanosheets was utilized as a nanostructured support. Pt NPs were uniformly deposited onto the MoO2@C support and a hierarchical Pt-based anode catalyst was successfully synthesized. Benefitting from several favourable features, including high exposed surface area, short diffusion distance, fast charge transfer and homogeneous Pt NPs dispersion, the Pt/MoO2@C catalyst exhibited an improved activity along with enhanced stability for methanol electrooxidation when compared with that of the Pt/C catalyst. This novel hierarchical structure is helpful for the further applications in hydrogen evolution reaction, supercapacitors and batteries.

Partially composite steel–concrete beams are commonly used in building construction, and so the behavior of such beams in fire is an important problem. This paper presents the results of an experimental investigation on the response of two composite beam specimens subject to fire exposure. The two specimens were nominally identical, except for the shear connection ratio. Based on room temperature calculations, one specimen was designed as fully composite, and the second was designed as partially composite with a 50% shear connection ratio. The concrete slab for each specimen was constructed with a flat steel deck and reinforcement was provided by a reinforcing bar truss. Both specimens were subject to a constant vertical load applied at four locations along the span and tested in a furnace with an ISO-834 standard fire. Both specimens achieved large deflections associated with flexural yielding of the composite beams and exhibited measured flexural capacities larger than predicted from Eurocode 4. Based on test measurements, the shear connection ratio had a significant influence on interface slip and uplift behavior of concrete slabs. Failure of the specimens was defined when the maximum deflection reached span/30. The fire exposure time needed to reach this definition of failure was nearly the same for both specimens, and was 51 min for the fully composite beam and 49 min for the partially composite beam. A companion paper considers the degradation of material properties with temperature and slips behavior of shear connectors at elevated temperatures and also provides an analytical approach to predict fire response of steel–concrete partially composite beams.

Cold spraying is a competitive additive manufacturing method featuring several unique characteristics and allows large-scale production of metallic components from a wide range of materials. In literature, high performance cold sprayed aluminum deposits produced using high-cost helium gas have been qualified for various applications. In this study, high performance aluminum alloy 6061 (AA6061) deposits were produced through a cold spray method using low-cost nitrogen gas enabled by an in-situ micro-forging effect (MF-CS). Results show that the MF-CS AA6061 deposit presents very low porosity as well as high ultimate tensile strength (UTS) and elastic modulus (E). Moreover, the MF-CS AA6061 deposit consists of superior equiaxed submicron fine Al grains with random orientations. However, the severe work hardening induced by intensive particle plastic deformation during deposition leads to very low ductility of the MF-CS AA6061 deposit. To eliminate this limitation, three strategies of heat treatments (stress relieving, recrystallization annealing and T6) were performed to the MF-CS AA6061 deposit. It was found that heat treatment generated complex effects on both inter-particle bonding and inner-particle microstructure (grain size, dislocation density and precipitation) and different strategies lead to different mechanical properties of AA6061 deposits. Among them, T6 heat-treated AA6061 deposits give the best overall mechanical properties with comparable UTS and E and only slightly inferior ductility to the corresponding T6 bulk.

By using nonlinear measurement error method, the compatible tree volume and above ground biomass equations were established based on the volume and biomass data of 150 sampling trees of natural spruce (Picea asperata). Two approaches, controlling directly under total aboveground biomass and controlling jointly from level to level, were used to design the compatible system for the total aboveground biomass and the biomass of four components (stem, bark, branch and foliage), and the total ground biomass could be estimated independently or estimated simultaneously in the system. The results showed that the R基于150株天然云杉实测材积和生物量数据，利用非线性度量误差方法，建立相容性立木材积与生物量方程，并采用总量直接控制方案和分级联合控制方案研建了地上总生物量与4个分项(干材、干皮、树枝、树叶)的相容性方程系统，其中又采取了独立估计和联合估计两种处理方法进行地上生物量的估计.结果表明：所建一元、二元相容性立木材积和地上生物量模型的材积和生物量决定系数均在0.85以上，最高达0.99，在胸径基础上增加树高变量能显著提高材积的预估效果，但对生物量的预估效果改进不大.就总量与分量相容性模型而言，分级联合控制方案所建的一元模型好于总量直接控制所建的一元模型，两种方案所建的二元模型效果相当.对一元、二元相容性生物量模型的拟合效果进行对比，结果显示，解释变量的增加明显提高了树枝和树叶生物量的拟合效果，对其他几个分量的拟合效果改善不大.对独立估计和联合估计的对比分析显示,两种估计方法几乎没有差异.

We developed aboveground biomass equations for poplar plantations in Jiangsu Province, China, both compatible with tree volume equations and additive systems. Biomass equations were fitted with 80 selected and previously harvested sample trees. Additivity property was assured by applying a “controlling directly under total biomass proportion function” approach. Weighted regression was used to correct heteroscedasticity. Parameters were estimated using a nonlinear error-in-variable model. The results indicated that (1), on average, stems constituted the largest proportion (71.5%) of total aboveground biomass; (2) the aboveground biomass equations, both compatible with tree volume equations and additive systems, obtained good model fitting and prediction, of which the coefficient of determination ranged from 0.903 to 0.987, and the total relative error and the mean prediction error were less than 2.0% and 10.0%, respectively; (3) adding H and CW into the additive system of biomass equations did not improve model fitting and performance as expected, especially for branches and foliage biomass; and (4) the additive systems of biomass equations presented here provided more reliable and accurate biomass predictions than the independent biomass equations fitted by ordinary least square regression. This system of additive biomass equations will prove to be applicable for estimating biomass of poplar plantations in Jiangsu Province of China.

Reaction of 3-acylcoumarins with α-bromoketones in the presence of a base give the cyclopropane derivatives in good stereoselectivity and moderate yield. The reaction was carried out at room temperature in mixed solvents without exclusion of moisture or air.

This paper reports the oxidation of functionalized internal alkynes with DMSO in the presence of I2 under microwave irradiation. This procedure gave 1,2-diaryldiketones in good yields.

A general and efficient copper(II) bromide catalyzed substitution reaction of propargylic alcohols with carbon and heteroatom-centered nucleophiles, such as alcohols and thiols, leading to the construction of C-O and C-S bonds has been developed. High product yields were obtained with excellent regioselectivity.

We synthesize a series of soluble phenylene-based electroluminescent (EL) polymers with deep blue emission by incorporations of dialkoxy groups (DRO-PPP) and alkoxy-phenyl group (EHB-PPP) on side chains as well as carbazole unit on main chain (EHB-PPP-Cz) using the Yamamoto coupling approach. The latter two modifications (EHB-PPP and EHB-PPP-Cz) lead to blue-shifts in absorption and emission maxima relative to DRO-PPP. In addition, the incorporation of carbazole as co-repeat-unit (EHB-PPP-Cz) leads to a raise of ionization potential (IP) to the level very close to that of the anode, PEDOT:PSS, to facilitate the hole injection. The maximum efficiency of the ITO/PEDOT:PSS/EHB-PPP-Cz/TPBI/CsF/Ca/Al device is 1.12 cd/A with a stable deep blue EL with CIE (0.16, 0.05).

By using the plane-wave-expansion method, the band structure of three-dimension phononic crystals was calculated, in which the cuboid scatterers were arranged in a host with a face-centered-cubic (FCC) structure. The influences of a few factors such as the component materials, the filling fraction of scatterers and the ratio (RHL) of the scatterer's height to its length on the band-gaps of phononic crystals were investigated. It is found that in the three-dimension solid phononic crystals with FCC structure, the optimum case to obtain band-gaps is to embed high-velocity and high-density scatterers in a low-velocity and low-density host. The maximum value of band-gap can be obtained when the filling fraction is in the middle value. It is also found that the symmetry of the scatterers strongly influences the band-gaps. For RHL 1, the width of the band-gap decreases as RHL increases. On the contrary, the width of the band-gap increases with the increase of RHL when RHL is smaller than 1.

A new chelating ligand, ferrocenecarboxaldehyde 2,4-dich lorobenzoylhydrazone (HFdcbh), and seven metal complexes, M(Fdcbh)2 [M˭Co(II), Ni(II), Cu(II), Hg(II)] and Ln(HFdcbh)Cl3. 4H2O2 [Ln˭La(III), Sm(III) and Er(III)], have been prepared and characterized by elemental analyses, IR and 1H NMR spectra. The deprotonated HFdcbh ligand acts as a bidentate donor, coordinating to the metal ions via its nitrogen and oxygen atoms.

State Key Laboratory of Applied Organic Chemistry, Lanzhou University . Key Laboratory of Nonferrous Metal Chemistry and Resources Utilization of Gansu Province, Lanzhou 730000, P. R. China E-mail : hgs@lzu.edu.cn Fax : 86-931-8912582 Manuscript received online 06 April 2012, revised 10 May 20I2, accepted 11May 20I2 Reactions of acyl chlorides with hydroxylamine hydrochloride and NaHCO3 generate the corresponding hydroxamic acid products in ethyl acetate and water at room temperature for 5 min. This is a simple and efficient method to synthesize a wide range of hydroxamic acids from carboxylic acids in excellent yield and high purity after simple post-treatment without chromatographic purification. In this process, the highlights are the simple separation of products and cheaply available reagents.

An algorithm applied to a real-time extraction image of vehicle is introduced. The algorithm include an image processing with a binarzation method, image grab for a vehicle with high speed, character isolator one by one, and neural network algorithm. The techniques include vehicles sensing, image garb control, vehicle license location, lighting and optic character recognition. The system is much more robust and faster than the traditional thresholding method.

A general and efficient copper(II) bromide catalyzed substitution reaction of propargylic alcohols with carbon and heteroatom-centered nucleophiles, such as alcohols and thiols, leading to the construction of C-O and C-S bonds has been developed. High product yields were obtained with excellent regioselectivity.

We report the conjugated polymer P(tBu-CBP) as a host with high triplet energy (E(T) 2.53 eV) and suitable HOMO (5.3 eV) and LUMO (2.04 eV) energy levels. Upon doping with green and red emission Ir-complexes, it gives devices with high luminous and external quantum efficiencies for green emission (23.7 cd/A, 6.57%) and for red emission (5.1 cd/A, 4.23%), respectively, and low turn-on voltage (3 V). For both devices, the efficiencies are higher than those of the corresponding devices with the same backbone P(3,6-Cz) as a host by a factor of 4, even though the latter has an E(T) (2.6 eV) slightly higher than that of the former. The results reflect that, in phosphorescent devices, the difference in E(T) between the host and guest is not the only factor that determines the device efficiency, and the present side group modification via the 9 position of carbazole also plays an important role, which allows a tuning of HOMO and LUMO levels to provide more balance in electron and hole fluxes and provides prevention from formation of excimer.

The main approaches for estimating the fundamental thermodynamic properties H 298 ° , S 298 ° , G 298 ° , and \({C_{{p_{298}}}}\) are discussed, including the Bonding Model developed recently in our laboratory. This model is successful for estimating S 298 ° and \({C_{{p_{298}}}}\) of the compounds with less ionic character, where the simple additivity scheme is not appropriate. A software program, Inorganic Properties Estimation System (IPES), is presented. IPES can give the above estimated values when experimental data are not available. It can also consult a thermo-data bank to see if the data desired already exist and output both the experimental and estimated values for evaluating the estimation methods.