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The practical application of 2,6-diamino-3,5-dinitropyrazine-1-oxide (LLM-105) highly requires the understanding of its thermal decomposition kinetics and thermal hazard prediction. In this study, ...

ZnMn2O4 and Zn1−xAlxMn2O4 were synthesized by a spray drying process followed by an annealing treatment. Their structural and electrochemical characteristics were investigated by SEM, XRD, XPS, charge–discharge tests and EIS. XPS data indicate that the substitution of Al3+ for Zn2+ causes manganese to be in a mixed valence state by a charge compensation mechanism. Moreover, the presence of this charge compensation significantly improves the electrochemical performance of Zn1−xAlxMn2O4, such as increasing the initial coulombic efficiency, stabilizing the cycleability as well as improving the rate capability. The sample with 2% Al doping shows the best performance, with a first cycle coulombic efficiency of 69.6% and a reversible capacity of 597.7 mA h g−1 after 100 cycles. Even at the high current density of 1600 mA g−1, it still retained a capacity of 558 mA h g−1.

Urban underground spaces (UUS), especially those containing natural resources that have not yet been utilized, have been recognized as important for future sustainable development in large cities. One of the key steps in city planning is to estimate the quality of urban underground space resources, since they are major determinants of suitable land use. Yet geological constraints are rarely taken into consideration in urban planning, nor are the uncertainties in the quality of the available assessments. Based on Fuzzy Set theory and the analytic hierarchy process, a 3D stepwise process for the quality assessment of geotechnical properties of natural resources in UUS is presented. The process includes an index system for construction factors; area partitioning; the extraction of geological attributes; the creation of a relative membership grade matrix; the evaluation of subject and destination layers; and indeterminacy analysis. A 3D geological model of the study area was introduced into the process that extracted geological attributes as constraints. This 3D geological model was coupled with borehole data for Foshan City, Guangdong province, South China, and the indeterminacies caused by the cell size and the geological strata constraints were analyzed. The results of the case study show that (1) a relatively correct result can be obtained if the cell size is near to the average sampling distance of the boreholes; (2) the constraints of the 3D geological model have a major role in establishing the UUS quality level and distribution, especially at the boundaries of the geological bodies; and (3) the assessment result is impacted by an interaction between the cell resolution and the geological model used.

A series of layered lithium-rich oxides 0.6Li[Li1/3Mn2/3(1−x)Zr2/3x]O2·0.4LiMn5/12Ni5/12Co1/6O2 (0 ≤ x ≤ 10%) have been prepared by a spray-dry method. The crystal structural and morphological properties of all the samples have been studied by XRD, XPS, SEM, HRTEM and SAED. XRD results reveal Zr4+ ions are doped into the lattice. HRTEM results suggest Zr4+ ions can stabilize the layered structural feature during cycles. The electrochemical properties are remarkably upgraded by Zr4+ ion doping. The discharge capacity of Zr4% doped samples remains 218.9 mA h g−1 after 100 cycles with a capacity retention of 84% at 20 mA g−1 between 2.0 and 4.8 V, while the undoped samples drop to 168.6 mA h g−1 with a capacity retention of 72%. Moreover, Zr4% doped samples show the lowest voltage decay, about 0.16 V lower than the undoped samples after 100 cycles. This study suggests suitable Zr4+ doping can improve the electrochemical performances and suppress voltage decay for layered lithium-rich oxides.

Copper manganese oxide Cu1.5Mn1.5O4, a novel anode material for lithium-ion batteries, was synthesized via a spray drying method. SEM images demonstrated a strong dependence of the morphologies of secondary and primary particles on the synthesis parameters. The surface electronic states and chemical compositions of manganese and copper in the sample were confirmed by XPS. The electrochemical results demonstrated that the sample synthesized at an annealing temperature of 700 °C showed great cycling performance, and retained a specific capacity of 464 mA h g−1 at a current of 100 mA g−1 after 60 cycles.

Cobalt and manganese oxides ((Co, Mn) 3 O 4 ) nanowires freely standing on nickel foam are prepared by a simple template-free growth process and heat treatment. The results show that the (Co, Mn) 3 O 4 composite forms a uniform film and densely covers the nickel foam substrate. The film is composed of nanowires with a diameter up to around 30–40 nm. The electrochemical capacitance behavior of the self-supported binderless nanowires electrode is investigated by cyclic voltammetry, galvanostatic charge/discharge test and electrochemical impedance spectroscopy. The (Co, Mn) 3 O 4 /Ni-foam electrode exhibits a high specific capacitance of 611 F g −1 at a charge/discharge current density of 2.38 A g −1 in 6.0 mol dm −3 KOH electrolyte. Furthermore, the (Co, Mn) 3 O 4 /Ni-foam electrode delivers a high energy density 13.6 Wh kg −1 , and even a high power density of 5.68 kW kg −1 . More importantly, the specific capacitance retention is 95% after 2000 charge/discharge cycles at 2.38 A g −1 and with columbic efficiency higher than 98%. This work suggests that the as-prepared (Co, Mn) 3 O 4 /Ni-foam electrode has potential application in electrochemical capacitors.

Nanostructured β-Ni(OH)2 with different morphologies are successfully grown on nickel foam using a template-free method by adjusting the anions of nickel salt precursors. The morphology is examined by scanning electron microscopy and the phase structure is analyzed by X-ray diffraction (XRD). The surface area is calculated with the Brunauer–Emmet–Teller (BET) model and the pore size distribution is determined with the Barett–Joyner–Halenda (BJH) method. The microstructure of β-Ni(OH)2 remarkably depends on the nickel salt precursors including Ni(NO3)2, NiCl2 and NiSO4. The electrochemical behaviours of β-Ni(OH)2 electrodes are investigated by cyclic voltammetry, galvanostatic charge/discharge test and electrochemical impedance spectroscopy in 6 mol dm−3 KOH solution. Results show that the β-Ni(OH)2/Ni-foam electrode prepared with NiSO4 exhibits the largest specific capacitance (1025.3 F g−1 at a current density of 1.0 A g−1), best reversibility and lowest charge transfer resistance due to its largest porosity and surface area.

In this work, MnO2 nanoflakes are electrochemically deposited on preformed C/TiO2 shell/core nanowire arrays to form a shell/shell/core arrays electrode (MnO2/C/TiO2). Their structure and surface morphology are studied by using X-ray diffraction analysis, X-ray photoelectron spectroscopy, scanning electron microscopy and transmission electron microscopy. The results suggest that MnO2 nanoflakes have well-distributed covered on the surface of C/TiO2 shell/core nanowire arrays. The MnO2/C/TiO2 shell/shell/core arrays are evaluated as a supercapacitor electrode material, which exhibits high specific capacitance of 639 F g−1 at a charge/discharge current density of 1 A g−1 and 78.7% specific capacitance retained after 1000 cycles. The superior pseudo-capacitive properties are attributed to the unique shell/shell/core structure for easy access of electrolyte ions, large surface to volume and high electrochemical activity. Our result shows that three-dimensional hierarchical nanostructures are being regarded advantageous for electrochemical energy applications.

Ni(OH) 2 nanosheets are directly grown on nickel foam by a simple template-free growth process. Their microstructure and surface morphology are studied by X-ray diffraction spectroscopy and scanning electron microscopy. The XRD and SEM results show that Ni(OH) 2 has a β-phase structure and covers the nickel foam skeleton with nanosheets. This β-Ni(OH) 2 /Ni-foam electrode exhibits a high specific electric quantity of 790.3 C g −1 approaching the theoretical value (1040.6 C g −1 ) and high electrochemical activity. Asymmetric supercapacitor has been fabricated successfully using β-Ni(OH) 2 /Ni-foam nanosheets as positive electrode and activated carbon as negative electrode in a KOH aqueous electrolyte. The electrochemical capacitances of this supercapacitor are investigated by cyclic voltammetry, galvanostatic charge/discharge and electrochemical impedance spectroscopy. An asymmetric supercapacitor AC/6 mol L −1 KOH/β-Ni(OH) 2 /Ni-foam could be cycled reversibly in the high-voltage region of 0–1.6 V and displays intriguing performances with a specific capacitance of 105.8 F g −1 and high energy density of 36.2 W h kg −1 . Importantly, this asymmetric supercapacitor device exhibits an excellent long cycle life along with 92% specific capacitance retained after 1000 cycles.

Fe 2 O 3 sheets have been synthesized on nickel foam by a simple template-free growth process and heat treatment. Structural characterization by SEM, TEM and BET indicates that the neighboring porous Fe 2 O 3 sheets form a open reaction space on the surface of the nickel foam skeletons. The sheets are confirmed to be pure Fe 2 O 3 phase by X-ray diffraction. The electrochemical capacitance behaviors of Fe 2 O 3 sheets electrode are investigated by cyclic voltammetry, galvanostatic charge/discharge and electrochemical impedance spectroscopy tests. The results show that the Fe 2 O 3 sheets electrode exhibits a specific capacitance as high as 147 F g −1 at 0.36 A g −1 in 1 mol dm −3 Li 2 SO 4 electrolyte, good cycling stability, and with a wide potential window of 1.0 V. The superior capacitance of Fe 2 O 3 sheets electrode might be attributed to its unique porous structure for easy access of electrolyte ions and high electrochemical activity.

Catalytic electrodes consisting of MmNi0.58Co0.07Mn0.04Al0.02 (AB5-type alloy) and multi-walled carbon nanotubes (MWNTs) are studied for NaBH4 electrooxidation and are characterized by scanning electron microscope and X-ray diffractometer. The NaBH4 electrooxidation performance on the AB5/MWNTs electrode is tested by cyclic voltammetry and chronoamperometry methods. The electrode performance is significantly affected by the content of MWNTs and the optimized content of MWNTs is found to be 2 wt.%. The steady state current density for NaBH4 electrooxidation at the AB5/MWNTs (2 wt.%) electrode is about twice of that at the AB5 electrode without MWNTs. The utilization efficiency of NaBH4 at the AB5/MWNTs electrode is 61.5% higher than that at the pristine AB5 electrode. The enhanced electrocatalytic activity and NaBH4 utilization at the AB5/MWNTs (2 wt.%) electrode can be attributed to MWNTs, which acts as a hydrogen adsorbent to diminish hydrogen release.

Al-substituted β-Ni(OH) 2 nanosheets are directly grown on nickel foam by a simple template-free growth process. Their microstructure and surface morphology are studied by X-ray diffraction spectroscopy, scanning electron microscopy and transmission electron microscopy. The SEM and TEM images show changes in the microstructure of β-Ni(OH) 2 by the addition of Al. The XRD results show that the α-phase Ni(OH) 2 appeared in Al-substituted Ni(OH) 2 electrodes. The effects of Al content on the electrochemical behaviors are investigated by cyclic voltammetry, galvanostatic charge/discharge and electrochemical impedance spectroscopy. The results demonstrate that the 7 mol% of Al in Ni(OH) 2 has better electrochemical performance, such as better reaction reversibility, higher proton diffusion coefficient, lower electrochemical impedance, higher specific capacity, and better cyclic stability. The as-prepared 7%-Al-Ni(OH) 2 electrode exhibits a specific discharge capacity of 324.5 mAh g −1 at 0.2 C, 220.6 mAh g −1 at 10 C, and 198.6 mAh g −1 at 30 C. The specific capacity loss is less than 8% after 200 charge/discharge cycles at 0.2 C and with columbic efficiency higher than 90%. This work suggests that the as-prepared 7%-Al-Ni(OH) 2 electrode has a promising future as higher charging/discharging rate materials for nickel metal hydride power battery.

Nanostructured CoxNi1−x(OH)2 (x = 0, 0.053, 0.068, 0.116, 0.192) composites are synthesized via a simple template-free growth process onto nickel foam by using a mixed aqueous solution of nickel nitrate, cobalt nitrate and ammonia. Their structure and surface morphology are characterized by X-ray diffraction, energy dispersive X-ray spectroscopy and scanning electron microscopy. The SEM images show changes in the microstructure of β-Ni(OH)2 by the doping of cobalt. The effects of cobalt content on the electrochemical behaviors of β-Ni(OH)2 are investigated by cyclic voltammetries, galvanostatic charge/discharge and electrochemical impedance spectroscopy. The results show that the Co0.116Ni0.884(OH)2 composite electrode exhibits a drastic improvement in the capacitive characteristics of β-Ni(OH)2 with a specific capacitance increase from 386.4 to 1082.6 F g−1 at a high discharging current density of 6 A g−1. This work suggests that the as-prepared Co0.116Ni0.884(OH)2 composite electrode has a promising future as higher charging/discharging rate materials for pseudo-supercapacitors.

Al-doped β-Ni(OH)2 nanosheets are prepared by a simple hydrothermal process onto nickel foam by using a mixed aqueous solution of nickel nitrate, aluminum nitrate and ammonia. Their structure and surface morphology are studied by using X-ray diffraction analysis, energy-dispersive X-ray spectroscopy and scanning electron microscopy. The SEM images show changes in the microstructure of β-Ni(OH)2 by the addition of Al. The XRD results show that the α-phase Ni(OH)2 appeared by the addition of Al. The effects of Al content on the electrochemical behaviors of β-Ni(OH)2 are investigated by cyclic voltammetrys, galvanostatic charge/discharge and electrochemical impedance spectroscopy. The results show a drastic improvement in the capacitive characteristics of β-Ni(OH)2 with a specific capacitance increase from 941.7 to 2122.6 F g−1 by the addition of just 3.4 mol% Al. This work suggests that the as-prepared Al0.034Ni0.966LDH electrode has a promising future as higher charging/discharging rate materials for pseudo-supercapacitors.

Cd(OH) 2 nanowires have been synthesized on nickel foam by a simple template-free growth method. Structural characterization by SEM and TEM indicated that the Cd(OH) 2 formed a porous film on the surface of the nickel foam skeletons. The thickness of the film reached approximately 25 μm and the nanowires have diameters of around ∼100 nm. The nanowires is confirmed to be pure phase hexagonal Cd(OH) 2 by X-ray diffraction. The electrochemical capacitance behaviors of the Cd(OH) 2 nanowires electrode are investigated by cyclic voltammetry, galvanostatic charge/discharge and electrochemical impedance spectroscopy tests. The Cd(OH) 2 electrode performed in different electrolyte demonstrates that nanowires possess supercapacitance properties in the presence of high concentration OH − ion. The specific capacitances as high as 1164.8 F g −1 at 1 A g −1 and 257.6 F g −1 at 10 A g −1 are obtained in 6 mol dm −3 KOH solution. The remarkably high capacitance of the Cd(OH) 2 nanowire electrode might be attributed to its unique 3D open structure for easy access of electrolyte ions, large surface area and high electrochemical activity. This work demonstrates that Cd(OH) 2 nanowires electrode has potential application in electrochemical capacitors.

Cu1.5Mn1.5O4 is prepared by spray drying of an aqueous solution of Cu(OAc)2, Mn(OAc)2, and citric acid with an outlet temperature of 185 °C followed by pre-sintering in air (300 °C, 3 h).

Nanostructured CuO with diverse morphology was directly grown on copper foam. Their supercapacitance performance was investigated and correlated with the morphology. CuO nanowires, nanosheets, and flower-like nanostructures were formed on copper foam which acts as both the substrate of CuO formation and the current collector of the electrode. Their morphology was examined by scanning and transmission electron microscopy and their phase structure was analyzed by X-ray diffraction spectroscopy. The supercapacitance of the nanostructured CuO on copper foam was investigated by cyclic voltammetry, galvanostatic charge/discharge measurements and electrochemical impedance spectroscopy. Results showed that the specific capacitance of the nanostructured CuO strongly depends on its morphology and dimension. CuO nanosheets exhibited higher specific capacitance than nanowires and flower-like nanostructure. The specific capacitance of the CuO nanosheets reached 212 F g −1 at a current density of 0.41 mA mg −1 in 6.0 mol dm −3 KOH electrolyte. The capacitance loss is around 15% after 850 charge/discharge cycles at 0.41 mA mg −1 and the majority of capacitance loss occurred in the initial 50 cycles (8.1%).

Co 3 O 4 nanowires have been successfully synthesized on nickel foam by a hydrothermal method. The morphology of Co 3 O 4 is examined by scanning and transmission electron microscopy and the phase structure of Co 3 O 4 nanowires is confirmed by X-ray diffraction. The electrochemical capacitance behavior of the Co 3 O 4 nanowires electrode is investigated by cyclic voltammetry, galvanostatic charge/discharge test and electrochemical impedance spectroscopy in 6 mol dm −3 KOH solution. The results show that the Co 3 O 4 nanowires have diameters of around 100 nm and the lengths up to 1–2 μm. The specific capacitance of Co 3 O 4 nanowires is 1019.58 F g −1 at 3.38 A g −1 and 466.06 F g −1 at 33.80 A g −1 . The capacitance loss is less than 5% after 1000 charge/discharge cycles at 3.38 A g −1 and with columbic efficiency higher than 98%. The enhancement of pseudocapacitive properties at a higher charging/discharging rate is due to the porous nanostructure and the high utilization of active material.

The electrode of array of CuO nanosheet is prepared via a template-free growth method, and it is doped by Ag via the silver mirror reaction. The morphology of Ag-doped CuO nanosheet is examined by scanning electron microscopy. The phase structure of the Ag-doped CuO nanosheet is analyzed by X-ray diffraction spectroscopy. The supercapacitance behavior of Ag-doped CuO nanosheet is investigated by cyclic voltammetry, galvanostatic charge/discharge test and electrochemical impedance spectroscopy. The results show that the thickness of a single nanosheet is up to around 150 nm. The specific capacitance of the Ag-doped CuO nanosheet electrode is 689 F g−1 at 1 A g−1 and 299 F g−1 at 10 A g−1, respectively, much higher than that of the unmodified CuO nanosheet arrays (418 F g−1 at 1 A g−1 and 127 F g−1 at 10 A g−1). The improved capacitance is explained in terms of the presence of dispersed Ag particle coated the CuO nanosheet arrays having good electrical conductivity.

Fe–N–C catalysts were prepared through metal-assisted polymerization method. Effects of carbon treatment, Fe loading, nitrogen source, and calcination temperature on the catalytic performance of the Fe–N–C for H2O2 electroreduction were measured by voltammetry and chronoamperometry. The Fe–N–C catalyst shows optimal performance when prepared with pretreated active carbon, 0.2 wt.% Fe, paranitroaniline (4-NA) and one-time calcination. The Fe–N–C catalyst displayed good performance and stability for electroreduction of H2O2 in alkaline solution. An Al–H2O2 semi-fuel cell was set up with Fe–N–C catalyst as cathode and Al as anode. The cell exhibits an open-circuit voltage of 1.3 V and its power density reached 51.4 mW cm−2 at 65 mA cm−2.

CuO nanosheet arrays freely standing on nickel foam are prepared via a template-free growth method. The morphology of CuO nanosheet arrays is examined by scanning and transmission electron microscopy and the phase structure of nanosheets is analyzed by X-ray diffraction spectroscopy. The supercapacitance of CuO nanosheet arrays is investigated by cyclic voltammetry, galvanostatic charge/discharge test and electrochemical impedance spectroscopy. The results show that the array of CuO nanosheets forms a uniform film of around 5 μm in thickness on nickel foam skeleton. The film is composed of clusters of arrays of nanosheets with a thickness up to around 150 nm. The CuO nanosheet arrays exhibit a specific capacitance of 569 F g−1 at a current density of 5 mA cm−2 in 6.0 mol dm−3 KOH electrolyte. The capacitance loss is less than 17.5% after 500 charge/discharge cycles at 10 mA cm−2 and with columbic efficiency higher than 93%.

The main character of melange strata in an orogenic belt is the integration of mixed materials due to the superposition, displacement or loss of various tectonic slices (blocks) of different origins and environments, different scales, different grades of deformation and metamorphism, and different stages of tectonic evolution. The approach to non-Smith strata in an orogenic belt is to focus on the understanding of the age, facies, tectonic setting of the original formation and the process of deformation-metamorphism of each tectonic slice, reconstruct the history of dispersal and integration of these tectonic slices in time and space, i.e. 4-dimensional. This paper studies the age and facies of the original formation of tectonic slices in the A’nyemaqen melange belt based on new data of radiolarians, sporo-pollen and trace fossils, and cast new lights on the research of the evolution process of that belt.