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Cu2ZnSnS4xSe4(1-x) (CZTSSe) has recently attracted much attention for solar water splitting due to its high absorption efficient and tunable bandgap. However, high quality CZTSSe thin films with good quality and adherence with the substrate are mainly based on physical deposition method, such as magnetron sputtering, which is expensive and energy consuming processes. Here, we have developed a novel and low-cost solution fabrication method and CZTSSe electrodes were synthesized at low temperature by hydrothermal treatment of chemical bath deposited SnS films. The quality and phase purity of CZTSSe thin films were greatly improved after annealing process and the effect of SnS thickness to the physical and photoelectrochemical (PEC) properties of CZTSSe thin films were detailedly studied. The fabrication of FTO/CZTSSe/CdS/TiO2/Pt photocathode improved the PEC properties of CZTSSe thin films greatly and the highest water splitting photocurrents of 7.2 mA/cm−2 had been achieved under simulated solar illumination. Furthermore, the electrode showed good stability and had a good incident photon-to-current efficiency (IPCE) response in the visible light range.

CdZnTe:In (CZT:In) films were deposited on fluorine-doped tin oxide-coated (FTO) substrates by close-spaced sublimation method, and the structural, morphological, and optical properties of CZT:In f...

To evaluate the effect of different inflation volume on the measurement accuracy of the modified cuff pressure measurement method in different shapes of cuffs, so as to provide reference for the correct monitoring of cuff pressure in clinic. In vitro study: The traditional cuff pressure measurement method (the cuff pressure gauge before measurement shows 0 cm H2O) and the modified cuff pressure measurement method (the cuff pressure before measurement shows 25 cm H2O, 28 cm H2O, 30 cm H2O or 32 cm H2O) were used to measure cylindrical and tapered cuffs, and the effect of different inflation volume on cuff pressure was analyzed statistically. Clinical study: patients with the artificial airway established by orotracheal intubation or tracheotomy in Neuro-ICU were prospectively selected as subjects, and the measurement procedure was the same as in vitro study. In vitro study showed that the pressure loss values of cylindrical cuff and tapered cuff using the traditional cuff pressure measurement method were (3.75 ± 0.31) cm H2O and (4.92 ± 0.44) cm H2O, respectively, and clinical study showed that the pressure loss values were (5.07 ± 0.83) cm H2O and (5.17 ± 0.93) cm H2O, respectively. The actual measured values measured by the traditional cuff pressure measurement method of the two cuff shapes were compared with the corrected target value of 28 cm H2O, and the differences were statistically significant (P < 0.000). Both in vitro and clinical study had shown that all differences between the actual measured value and the corrected target value using the modified cuff pressure measurement method (measured with 25 cm H2O, 30 cm H2O, 32 cm H2O) were statistically significant (P < 0.000), and the range of overall differences was (0–1.23 ± 0.25) cm H2O. In vitro study had shown that the pressure variation coefficient (CV) of the tapered cuff was greater than that of the cylindrical cuff, and the difference was statistically significant (3.08 ± 0.25 VS 2.41 ± 0.21, P < 0.000). The traditional cuff pressure measurement method can directly lead to the cuff pressure drop, which is easy to cause the leakage of secretions on the cuffs and the misjudgment of the cuff pressure by medical personnel. However, the modified cuff pressure measurement method can effectively reduce cuff pressure loss, and taking the actual cuff pressure value as the inflation volume is the highest measurement accuracy.The tapered cuff is more susceptible to air volume, so it is necessary to pay attention to its measurement and correction in clinical practice.

Outstanding mechanical properties and high thermal conductivity epoxy composites are being developed and are becoming urgent in the electronic and aerospace industries. Boron nitride nanosheet (BN)...

In the electronics and aerospace industries, epoxy resins are generally regarded as economical and efficient adhesives and have a high status. However, epoxy resins are highly crosslinked polymers and are very brittle adhesives where they are prone to fast crack propagation under dynamic loads. Therefore, it is very necessary to enhance the toughness of epoxy resin adhesives. Nano-rubber has been proved to be an important toughening agent for epoxy resin, which can significantly improve the fracture toughness of epoxy resin. However, increasing the toughness of epoxy resin by adding nanomaterials is often accompanied by decreasing the strength and stiffness of resin. Therefore, in this work, rigid nano-silica particles were added to improve the rigidity and tensile strength reduction caused by the addition of rubber particles. And further increase the toughness of the epoxy resin to obtain an epoxy adhesive with balanced stiffness-toughness. As a result, it can be found that the addition of silica particles can significantly improve the decrease in stiffness caused by the addition of rubber particles. For example, Young’s modulus and tensile strength are increased by 28%, and 23%, respectively, with 4% silica is added based on rubber particles. Through the single lap shear experiment, it is found that the shear strength of the epoxy/RnP/silica composite adhesive has increased, which further proves that the addition of nano-silica particles can increase the stiffness of the epoxy composite. The dynamic mechanical analysis experiment found that after adding nano-silica particles, the storage modulus of epoxy composites increased, which also shows that adding nano-silica particles can improve the stiffness of epoxy composites. Scanning electron microscopy analysis was performed to study the reinforcement mechanism of epoxy/RnP/silica composite materials. The thermal stability of epoxy composites was characterized by Dynamic mechanical analysis and thermogravimetric analysis.

Constructing nanostructures with multi-components and delicate architecture exhibits huge potential to improve the lithium storage performance of electrodes. Herein, we report a novel yolk-double-shell structure with complex chemical compositions. Starting with a core-shell structured Co-ZIF@ZnCo-ZIF as a precursor via a simple selenization process, yolk-double-shell polyhedra that assembled by nanosized Co0.85Se@N-doped carbon as the yolk and the first shell and nanosized Co0.85Se@N-doped carbon and ZnSe@N-doped carbon hetero-components as the second shell (marked as Co0.85Se@NC/ZnSe@NC-YDS) are synthesized. Benefiting from their multiple structural advantages, such as high surface area, large pore volume, uniform carbon coating, and intimate heterostructures, Co0.85Se@NC/ZnSe@NC-YDS exhibits high reversible capacity (1047 mA h g-1) and good rate capability for lithium storage. More importantly, even after 3000 cycles at 5.0 A g-1, an impressive reversible capacity of 468 mA h g-1 is retained with no capacity decay. After repeated discharge/charge processes, the integrated yolk-double-shell structure is still reserved, due to its structural and compositional advantages, which contribute to the enhanced rate and cycling performance.

Controlling the microstructure and composition of electrodes is crucial to enhance their rate capability and cycling stability for lithium storage. Inspired by the highly interconnected network and good mechanical integrity of an ant-nest architecture, herein, a biomimetic strategy is proposed to enhance the electrochemical performance of Cu2-xSe. After facile carbonization and selenization treatments, the 3D Cu-MOF is successfully transformed into the final ant-nest-like Cu2-xSe@C (AN-Cu2-xSe@C). The AN-Cu2-xSe@C is composed of interconnected Cu2-xSe channels with amorphous carbon coated on the outer surface. The 3D interconnected channels within the AN-Cu2-xSe@C provide fast charge transport pathways and enhanced structural integrity to tolerate the large volume fluctuations of Cu2-xSe during cycling. When applied as the anode for lithium storage, the AN-Cu2-xSe@C shows remarkable electrochemical performance with a high capacity of 1452 mA h g-1 after 1200 cycles at 1.0 A g-1 and 879 mA h g-1 after 2500 cycles at 10.0 A g-1, respectively. Mechanism investigations demonstrate that the AN-Cu2-xSe@C experiences complicated conversion-intercalation co-existence reactions upon cycling. The existence of capacitive behaviour (74%) also contributes to the extended cycling performance. Our work offers a new avenue for designing a high performance electrode using the biomimetic concept.

To miniaturize or integrate electrochemical devices, new types of nanoparticle-based Ag/AgCl quasi-reference electrodes (qREs) have been generated via screen printing and inkjet printing. However, their nanostructures and addition of binder materials produce unsatisfactory conductivity and sensitivity. Herein, a novel Ag/AgCl qRE with a nanowire-and-nanoparticle (NWP) structure is developed. The unique NWP-Ag/AgCl qRE is first generated by drop coating silver nanowires (AgNWs) on poly(dimethylsiloxane) (PDMS), followed by chemical chlorination. Because the nanowires form well-connected network, the novel NWP-Ag/AgCl qRE creates efficient charge transport paths as well as porous 3D structures that enable faster electrolyte percolation. The NWP-Ag/AgCl qRE reaches 95% stable potential fast (6.4 s) and is extremely stable (at least 8000 s continuous measurement and 6-month shelf life). The NWP-Ag/AgCl qRE on PDMS provides ultracomfortable tactile experience that is suitable for skin-contact electrophysiology. The NWP-Ag/AgCl qRE has also been successfully applied to the detection of glucose with a linear range of 1 μM–1900 μM. This study establishes a new printer-free Ag/AgCl qRE fabrication method with simple chemistry. Furthermore, the new method is a truly transformatively efficient and cost-effective approach with substantial industrial applications to electrophysiology and electrochemical device-making.

Cd1−xZnxTe films were prepared on borosilicate glass substrate using RF magnetron sputtering in this work. The effects of sputtering power, sputtering pressure and substrate temperature on the properties of the films were investigated in detail. The films were annealed in CdCl2 atmosphere for 2 h at 200 °C, 300 °C, and 400 °C, respectively. The effects of annealing treatment on the properties of the films were also investigated. The properties of the films were investigated by x-ray diffraction, atomic force microscopy, and current–voltage (I–V) characterization. The results indicate that crystalline quality and the average grain size of the films increases with the increases of sputtering power. The grain size of the films becomes larger as the substrate temperature increases. The Zn concentration of the films rises as the sputtering pressure increases. After annealing, the grain size of the films becomes larger, furthermore, the resistivity decreases.

A series of polyamidoamine (PAMAM) immobilized TEMPO macromolecular catalysts were prepared by condensation reduction reactions between carbonyl groups in 4-O-TEMPO and primary amines in PAMAM. The macromolecular catalyst and NaBr/NaClO were used as catalytic system for selective oxidation of cellulose in aqueous medium. Effects of various factors, such as TEMPO loading ratios and PAMAM generations, were studied on the catalytic performances. Compared with free TEMPO, the macromolecular catalyst with less than 50 % TEMPO loading ratio had a higher reaction rate in the initial stage of the reaction. Especially, the reaction rate of G1.0 PAMAM with 30 % TEMPO loading ratio was comparable to free TEMPO in the whole reaction process. Its cellulose oxidation degree (or catalytic activity) was also equivalent to the level of free TEMPO. Interestingly, the cellulose depolymerization degree of macromolecular catalyst was not affected by the cellulose oxidation degree and was lower than that of free TEMPO. The macromolecular catalyst could be recycled efficiently by the combination of supernatant circulation and salting-out extraction, and the recycling performance was excellent.

Cadmium zinc telluride (CdZnTe) is considered to be an ideal material for manufacturing high-energy radiation detectors with large scale and long-term stability. To solve the problem of film fragmentation during the process of preparing CdZnTe thick films using the close-spaced sublimation method, Ga-doped ZnO (GZO) was chosen as the substrate for CdZnTe film growth, since it has a similar thermal expansion coefficient, lower lattice mismatch, and better adhesion compared with CdZnTe. For comparison, borosilicate glass and fluorine-doped tin oxide substrates were also used to deposit CdZnTe under the same preparation conditions. The structure and physical properties of the CdZnTe film were investigated in detail by using atomic force microscopy, scanning electron microscopy, energy-dispersive spectrometry, x-ray diffraction analysis, and current–voltage (I–V) measurements. The results indicated that CdZnTe film grown on GZO film substrate has large grain size, high growth rate, high quality, and good adhesion.

Fe-doped ZnO (Fe–ZnO) mesoporous nanoparticles have been synthesized via a facile hydrothermal method, which utilizes pluronic triblock copolymer polyethylene glycol–polypropylene glycol–polyethylene glycol (PEO-PPO-PEO) as the pore-forming agent. Fe–ZnO composites have an unique porous structure. Their pore sizes increase with Fe-doping concentration and reach a maximum as Fe concentration is 15 at.%; the specific surface area of synthesized mesoporous Fe–ZnO nanoparticles reaches a maximum as the Fe concentration is about 11 at.%. Electron microscopy, vapor pressure isotherm measurements and photoluminescence (PL) were used to characterize synthesized Fe–ZnO composites. Fe–ZnO-based gas sensors exhibit excellent response in detecting ethanol; the sensing response of Fe(11 at.%)–ZnO reaches 319.8, which is significantly higher than most of the ZnO-based gaseous sensors. The improved sensitivity is ascribed to the increase of oxygen-related defects and specific surface area of Fe–ZnO composites.

The use of metal-organic frameworks (MOFs) for adsorption cooling has won increasing research interests due to their outstanding adsorption performance. Zr-MOFs with relatively stable water stability and distinct structure properties are potential adsorbents for cooling. In this work, three Zr-MOFs: UiO-66, UiO-67 and NU-1000 with varying pore sizes were synthesized, and their water and ethanol adsorption isotherms were measured. The specific cooling effects (SCE) and coefficient of performance (COP) of MOF/water and MOF/ethanol working pairs in adsorption cooling system (ACS) were evaluated by adsorption system modeling. The results revealed that the MOFs with small pores and low steps (P/P0) (i.e. UiO-66) in isotherms are favorable for water working fluid, which can achieve high SCE and COP at relative low temperatures. In contrast, MOFs with large pores and suitable steps (i.e. NU-1000) is preferential for ethanol working fluid due to the high uptake. Although water working fluid generally exhibited higher SCE and COP than ethanol, MOF/ethanol outperformed MOF/water because the equivalent cooling performance can be achieved at low temperature as well as the high recycle stability of MOFs/ethanol working pairs.

As lead-containing products, such as lead batteries, are widely used, water pollution problems caused by Pb2+ show a significant threat to the ecosystem and human health. To overcome this serious problem, the modified poly(methyl methacrylate) (PMMA)/chitosan (CS) composites were prepared by adding CS into the PMMA matrix as functional filler and surface modification. The structure, thermal stability, size, morphology and adsorption properties of the modified PMMA/CS composites were characterized by Fourier transform infrared spectroscopy, thermogravimetric analysis, scanning electron microscopy, and inductively coupled plasma optical atomic emission spectrometry. The results indicated that the modified PMMA/CS composites had a uniform size of about 1 μm and showed quite good thermal stability. In addition, the Pb2+ removal of the modified PMMA/CS composite reached up to 98% when the initial Pb2+ concentrations are under 100 mg l−1. The results of the adsorption isotherms indicated that the Langmuir isotherm fits best to the experimental data when compared with the Freundlich isotherm and Temkin isotherm. All these results demonstrate that modified PMMA/CS has a good adsorption property and can be a promising adsorbent for chelating Pb2+.

In this study, the influence of length of flexible groups on the properties of poly(amide–imide)s (PAIs), three-model polymers (poly(amide–imide)-4-aminobutyric acid, poly(amide–imide)-6-aminocaproic acid, and poly(amide–imide)-11-aminoundecanoic acid) possessing different flexible methylene units ((CH2)3, (CH2)5, and (CH2)10) in the main chain were designed. With increasing the number of methylene units, it is found that the tensile strength of PAIs decreased from 75 MPa to 55 MPa; meanwhile, the elongation at break increased from 6% to 15%. On the other hand, the glass transition temperature decreased from 207°C to 112°C; fortunately, the starting decomposition temperature kept almost same with a high point around 400°C. Furthermore, the PAI with (CH2)10unit in the main chain is a semicrystalline polymer, while the one with (CH2)5or (CH2)3unit is an amorphous material. In other words, the length of the flexible chain in the polymer backbone not only plays an important role in mechanical and thermal performances but also affects their phase transition. These findings highlight the important role of structural modification in high-performance polymers and may help in the further development of novel PAIs for their potential applications in advanced technology.

Polyvinyl alcohol (PVA) filled with different kinds of ZnO whisker was prepared by chemical cross-linking reaction. It was found that the ZnO whiskers dispersed uniformly after being modified by 3-aminopropyltriethoxysilane (APTES). The PVA/tetrapod-shaped ZnO (PVA/tetra-ZnO) composites showed better adsorption performance than other kinds of PVA/ZnO composites. The framework-supported pore-channel structure was beneficial for the transmission and adsorption of heavy metal ions, and the formation of “brush” pore-channel of PVA/tetra-ZnO composites can effectively retain and capture the heavy metal ions. The PVA/tetra-ZnO composites presented well adsorption on Pb(II), Cd(II), and Cr(III) ions than Ni(II) and showed relatively selective removal on Pb(II) and Cr(III) ions. The adsorbed heavy metal ions presented gradient distribution with high content in the out layer and low content in the inner layer. Pb(II) adsorption capacity qe increased gradually with the increase of initial solution concentration and contact time which tended to be stable at 400 mg/L and 800 min. The maximal adsorption capacity qm obtained by nonlinear fitting reached to about 116 mg/g which was very close to the experiment data. Adsorption isotherm results indicated the monolayer adsorption process of the Langmuir model and the adsorption kinetics data fitted well to the pseudo-second-order model. The adsorption process was spontaneous and the high temperature was in favor of adsorption. The adsorption mechanism was explored as the combination of coordination and ion exchange. Besides, the PVA/tetra-ZnO composites exhibited better stress stability, thermo stability, and favorable regeneration than neat PVA.

Planar hybrid heterojunction PbS-polymer solar cell is lagging behind compared with its counterparts due to limited studies. This work is aimed to understand the mechanisms of this technology and improve its performance, by tuning the quantum dot (QD) bandgap (Eg) and the modified ligand exchange and fabrication process. With planar structure of PbS QDs and PTB7-Th, relative high VOC (>0.5 V) was obtained in device with QD Eg in the range of 1.3–2.0 eV. The highest VOC and JSC was recorded to be 0.645 V and of 15.5 mA/cm2 respectively. And the best device performance with PCE of 4.43% (VOC 0.561 V, JSC 14.47 mA/cm2 and FF 54.6%) was demonstrated. Which is over double the performance of previously reported similar planar hybrid PbS-organic heterojunction solar cells, due to the improved and balanced parameters after optimization.

In this article, Al or N-doped ZnO films are prepared by wet chemical deposition method, and then the Al-ZnO/N-ZnO homojunction photodiode is structured. The influence of triethanolamine (TEA) content and deposition temperature on the structure, phase, and optical-electrical properties of N-ZnO films is investigated. The results of X-ray Diffraction (XRD) measurement show that the N-ZnO films have a hexagonal wurtzite structure with a preferred growth orientation along (002) crystal plane. The obvious Raman peak appeared at 436 cm−1 should be assigned to non-polar high-frequency E2H mode, which indicates the good crystallinity of N-ZnO film. The results of low temperature photoluminescence (LT-PL) measurement exhibit that the peak of UV emission, which shifts from 386 to 390 nm with the increase in measurement temperature from 50 to 250 K, may be mainly the exciton emission, coming from shallow donor Zni to valence band (Zni →VB: ΔE~3.15 eV) or conduction band to the shallow acceptor No (CB→No: ΔE~3.215 eV). Two visible emissions peaks may be attributed to the electron transitions from the single charged oxygen vacancies Vo+ and the double charged oxygen vacancies Vo++ defects, respectively. Three infrared emission peaks may be related to the electron transitions from the transition from deep donor level (Vo, Zni) to deep acceptor level (OZn) or the intra band transition between two states of Vo and Zni. For the response times of Al-ZnO/N-ZnO homojunction photodiode, the rise time (τr) is

SnS has been widely used in photoelectric devices due to its special band gap of 1.2–1.5 eV. Here, we reported on the fabrication of SnS nanosheets and the effect of synthesis condition together with heat treatment on its physical properties. The obtained band gap of the SnS nanosheets is in the rage of 1.37–1.41 eV. It was found that the photo-current density of a thin film comprised of SnS nanosheets could be enhanced significantly by annealing treatment. The maximum photo-current density of the stack structure of FTO/SnS/CdS/Pt was high as 389.5 μA cm−2, rendering its potential application in high efficiency solar hydrogen production.

SnS:In thin films have been deposited on Mo substrates by chemical bath deposition method in acidic solution. The influences of different In-doped concentrations on the morphological, structural, optical properties and phase purities of SnS thin films have been investigated. Many sheet-like particles exist in the deposited SnS:In thin films. The doping of indium will decrease the thicknesses of the deposited thin films. The studies of photo-electrochemical (PEC) properties of SnS:In (In,10 at.%) thin films indicate that their PEC properties are enhanced by the annealing process. The fabrication of Pt/CdS/annealed SnS:In/Mo photocathode can further enhance the photo-current density to 0.790 mA·cm−2 at −0.4 V.

Adsorption-driven heat pumps (AHPs) based on metal–organic frameworks (MOFs) have been garnering rapidly growing research interests due to their outstanding adsorption performance. However, the quick discovery of potential MOF candidates for cooling/heating from a large number of MOFs is still a hurdle for developing highly efficient AHPs. In this work, we performed high-throughput computational screening based on grand canonical Monte Carlo (GCMC) simulations to assess the adsorption cooling efficiencies (i.e., coefficient of performance for cooling, COPC) of 1527 computationally ready experimental (CoRE) MOF structures using ethanol as the working fluid. On the basis of the obtained correlations between the MOF structures, properties, adsorption performance, and adsorption cooling efficiency, we found that the pore size of 10–15 A, rather than larger pores, was favorable for both ethanol working capacity (ΔW) and COPC. Moreover, both ΔW and averaged enthalpy of adsorption (〈ΔadsH〉) played dominant roles in determining the COPC value. Principle component analysis (PCA) and decision tree (DT) modeling revealed that there is interplay between the pore size, ΔW, and 〈ΔadsH〉. For MOFs with low working capacities (ΔW ≤ 0.27 g g−1), large pore size is favorable for COPC; for MOFs with high working capacities (ΔW > 0.27 g g−1), low 〈ΔadsH〉 is more important for COPC. Furthermore, the top-performing MOFs exhibited stepwise adsorption and low Henry's constant, both of which are beneficial for COPC. In addition, we revealed that the incommensurate total interaction energy of MOF–ethanol pairs between the preheating and desorption processes will benefit ΔW, thereby eventually leading to improved COPC, and vice versa. Finally, the evolutionary tendency of screening validated our screening strategy and structure–property relationship, which was also supported by the cooling efficiency predicted by the mathematical model using experimentally measured isotherms.

Steam flooding (SF) is an effective technology to exploit thin heavy-oil reservoirs. Long-term indoor experiments and field tests, however, show that SF has the problems of great heat loss and a limited steam-chamber affected area, which severely limits steam utility and the ultimate economic benefit of thin heavy-oil reservoirs. In this paper, based on a specific oil field in China, we designed a two-dimensional experimental model to investigate the effect of solvents on steam-chamber distribution and production dynamics, and the effect of heat-solvent coupling (molar ratio of steam and solvent) on steam-chamber front expansion. Then, based on the parameters of indoor experiments, we built a numerical model by CMG STARS to further study the influence of solvent migration in steam chambers under different injection molar ratios of steam and solvent. The results show that: i) According to experimental results, for SF, steam-chamber affected area is limited and oil recovery is low which is only 21.3%. After the solvent is added, steam-chamber affected area can be largely enlarged and displacement efficiency can be enhanced. Compared with SF, oil recovery of Solvent-Enhanced Steam Flooding (SESF) can be enhanced to 34.3%–58.3%; ii) According to the results of the numerical simulation, oil viscosity can be greatly reduced after the solvent is added. As a result, steam-chamber expansion can be improved, steam-chamber affected area can be enlarged, and displacement efficiency can be enhanced; iii) the optimal injection molar ratio of steam and solvent was around 8:1 for SESF.

α-Fe2O3 grains grafted onto TiO2/carbon nanofibers (CNFs) for use as anode materials in lithium-ion batteries have been successfully fabricated by electrospinning and vapor-solid reaction (VSR). Scanning electron microscopy (SEM), transmission electron microscopy (TEM) and N2 adsorption-desorption isotherms reveal that the ultrafine α-Fe2O3 nanoparticles were formed on the TiO2/CNFs and have uniform dispersion along the fiber direction. The VSR approach could retard nucleation, thus making TiO2/CNFs with small Fe2O3 grains grafting (approximately 5 nm in diameter). The TiO2/CNFs are capable of buffering the large volume variation of α-Fe2O3 during cycling and preventing electrode pulverization and aggregation, as well as providing sufficiently large interstitial space within the crystallographic structure to host Li ions. The electrochemical properties of the composite electrodes were tested by galvanostatic cycling at both constant and variable current rates. The composite delivers both good rate capability under an uprated current density of 1000 mA g−1 and especially enhanced cycle stability (∼600 mA h g−1 after 200 cycles at a current density of 1000 mA g−1). The super electrochemical performance is attributed to a synergetic effect between α-Fe2O3 and TiO2-CNFs as well as the three- dimensional (3D) network, which contributes to greatly enhanced diffusion kinetics and structural stability for lithium-ion batteries. This VSR approach can be extended to other hierarchical metal oxide nanostructures for favorable applications in electrochemical devices.

AlN ceramic substrates (c-AlN), with excellent thermal conductivity, were used to deposit high-quality polycrystalline CdZnTe (CZT) thick films for the first time. Meanwhile, AlN transition layers, made by magnetron sputtering method, have been introduced and annealed to modulate the interface properties of CZT/c-AlN composite structures for UV photodetectors. The relationship between the structure as well as performance of CZT films and the anneal temperature of AlN transition layers was studied by SEM, XRD, EDS, UV–vis spectra, XPS and current–voltage (I-V) characteristic. The CZT films deposited on the AlN transition layer annealed at 1200 °C have the best properties, with the full width at half maximum (FWHM) and leakage current of 0.163°and 2.15 × 10−9 A, respectively. The interface regulation can effectively promote the crystallinity of CZT films and lead to optimum UV detection performance of CZT/AlN composite structures.

Chromium(vi) [Cr(vi)] has been shown to be toxic to organisms due to its mutagenicity and carcinogenicity. Therefore, the exploitation of probes with low toxicity and high sensitivity for Cr(vi) detection is needed. In this study, a one-step, solvent-free, and microwave-assisted method was developed for the preparation of nitrogen-doped carbon dots (N-CDs). The reaction could be finished in just three minutes, and the yield of the dots could reach 58.5%; the as-prepared N-CDs exhibited excellent water solubility, emitted bright cyan fluorescence with a high quantum yield of 38.88%, and possessed excitation- and concentration-dependent characteristics. The N-CDs could be effectively applied to Cr(vi) detection with a linear range of 1-100 μM, and the detection limit could be as low as 0.12 μM. The quenching mechanism was responsible for the inner filter effect, and the quenched fluorescence could be recovered with a linear range of 5-100 μM by the addition of ascorbic acid. We showed that the fluorescent probes could even be employed for the detection of Cr(vi) in river water and for bio-imaging because of their nearly zero cytotoxicity; this showed the potential application of these probes in ion detection and cellular bioimaging. Herein, we have provided an effective strategy to rapidly obtain high-quality N-CDs using a solid-phase microwave method, and the as-prepared N-CDs exhibit various potential applications in environmental and biological fields.

An ionic liquid-based ionically cross-linked gel polymer electrolyte (GPE-ILs) was successfully synthesized using acrylic acid, 2-diethylaminoethyl methacrylate, methyl methacrylate, and ionic liquids. Electrochromic devices (ECDs) with an architecture of glass/FTO/WO3/GPE-ILs/FTO/glass were fabricated by a laminating technology. The devices showed performances of large optical modulation of 49.9% at 650 nm, short switching times with the coloration time (tc) of 7 s and the bleaching time (tb) of 4 s, high coloration efficiency of 96.2 cm2 C-1, and cycling stability of 200 cycles. The GPE-ILs exhibits high ionic conductivity, superior thermal stability and good self-healing ability. GPE-ILs demonstrates an ionic conductivity of 3.19 × 10-3 S cm-1 at 25 °C and the same ions migration behaviors with most widely used liquid electrolyte between −10 and 80 °C maintains more than 80% of its tensile strength after self-healing and received only 5% weight loss at 300 °C.

Osteoarthritis is a leading cause of disability affecting an increasing number of individuals. However, cartilage replacement therapies are inadequate, and better cartilage regeneration products must be developed. In this work, we describe a human mesenchymal stem cell (hMSC)-based approach for fabricating extracellular matrix (ECM) scaffolds from tissue-engineered cartilage sheets and then for inducing chondrogenesis of reseeded hMSCs within the ECM scaffolds. Two types of ECM scaffolds were fabricated: one from high-density hMSC sheets cultured with media-supplemented transforming growth factor beta-1 (TGF-β1; -MS) and the other from high-density hMSC sheets incorporated with TGF-β1-laden gelatin microspheres (+MS), which significantly enhance chondrogenesis within the sheet system. Interestingly, when scaffolds were reseeded with hMSCs, -MS scaffolds lead to significantly more glycosaminoglycan (GAG) accumulation than +MS scaffolds. Importantly, ECM scaffolds could be soak loaded with TGF-β1 to produce cartilage of similar quality as that of constructs cultured with TGF-β1 in the media, thereby removing the need for supplementing the media with the growth factor. Lastly, tissues formed with the scaffolds were larger with more uniform cartilage matrix elaboration compared to scaffold-free groups making this strategy a clinically promising auto- or allogeneic therapy.

Reducing the secondary electron yield (SEY) of Ag-plated aluminum alloy is important for high-power microwave components. In this work, Cu doped carbon films are prepared and the secondary electron emission characteristics are studied systematically. The secondary electron coefficient δ max of carbon films increases with the Cu contents increasing at first, and then decreases to 1.53 at a high doping ratio of 0.645. From the viewpoint of surface structure, the higher the content of Cu is, the rougher the surface is, since more cluster particles appear on the surface due to the small solid solubility of Cu in the amorphous carbon network. However, from viewpoint of the electronic structure, the reduction of the sp2 hybrid bonds will increase the SEY effect as the content of Cu increases, due to the decreasing probability of collision with free electrons. Thus, the two mechanisms would compete and coexist to affect the SEY characteristics in Cu doped carbon films.

In this study, the feasibility of assessing the chemical composition in bone using the multi-wavelength photoacoustic analysis (MWPA) method was investigated. By illuminating a bone specimen using laser light with a wavelength tunable over an optical spectrum from 680 nm to 950 nm, the optical absorption spectrum of the bone was acquired. Then, with the optical absorption spectra of all the optically absorbing chemical components in the bone known, a spectral unmixing procedure was performed to quantitatively assess the relative content of each chemical component. The experimental results from porcine rib bones demonstrated that the contents of the chemical components, including not only non-organic materials such as minerals and water but also organic materials including oxygenated hemoglobin, deoxygenated hemoglobin, lipid, and collagen, can all be assessed by MWPA. As the chemical composition in the bone is directly associated with functional and metabolic activities, the finding from this study suggests that the MWPA method could offer a new diagnostic tool for the non-invasive evaluation of bone health.

Secondary electron (SE) emission is a superficial physical phenomenon. The range of SEs excited in materials which are finally emitted from the surface is generally within a few tens of nanometers. SE emission from materials by electron irradiation has great dependence on surface quality, such as gas adsorption, oxidation, contamination, and morphology. In this paper, the influence of surface adsorption of N2, O2, Ar and air on SE yield (SEY) and the SE spectrum (SES) of copper was investigated by experiment. The measured SEY and SES were compared before and after the copper surface was sputtered by Ar ions. The results show that gas adsorption could increase SEY, and air adsorption lead to the maximum increase, Ar adsorption the minimum. Meanwhile, the relationship between the SES and the SEY was deduced and validated by the experiment. It was also found in the experiment that the Ar ion sputtering or heating alone can effectively reduce the SEY, while heating the sample after Ar ion sputtering increases SEY. The reasons for the variation of the SEYs with gas adsorption, sputtering and heating are preliminarily explained with the help of in-situ XPS. Accordingly, the research helps to further reveal the mechanism of SEE influenced by complex superficial factors.

Dithizone is known to be very effective for heavy metal ions retention and widely used as developer in detection methods. To explore a novel surface modified polymer microspheres, this paper prepared a novel modified polystyrene (PS-g-D) microspheres by grafting dithizone as the complexing agent and developer on the surface of PS microspheres. The structure of PS-g-D was analyzed by FT-IR, and the formation of dithizone grafted PS microspheres was proved. The thermal stability and surface morphology of PS and modified PS were studied by TGA and SEM. PS-g-D had a uniform diameter of about 1 μm and exhibited a good thermal stability. The Pb2+ removal increased and reached up to 99% with the decrease of initial Pb2+ concentrations. The study of the isotherms model showed that the adsorption between PS-g-D and Pb2+ is consistent with the Langmuir and Temkin adsorption isotherm models. The adsorption kinetics of PS-g-D is described well by the pseudo-second-order model. It can be seen that the modified PS microspheres exhibit a good adsorption property, and has real potential as a novel adsorbent for water treatment industry due to the introduction of dithizone as complexing agent and developer.

CdTe thin films have been prepared by electrochemical deposition. The morphological, structural, and optical properties of CdTe thin films deposited with different deposition time were investigated, and the influence of film thickness on the photoelectric characteristics of CdTe thin films was studied. At the deposition time of 1.5 h, CdTe thin films had good optical properties and the photocurrent reached 20 &mu, Acm&minus, 2. Furthermore, the Pt/CdS/CdTe/FTO structure was prepared to improve its PEC stability and the photocurrent of 240 &mu, 2 had been achieved.

This work investigated the effect of graphene nanoplatelets (GNPs) on the water absorption and impact resistance of fibre-reinforced metal laminates (FMLs) under hygrothermal and salt spray environments. Containing GNPs of 0.1, 0.3, 0.5 and 1.0 wt%, the resulting nanocomposite FMLs were investigated for 28 days of aging in the environments. The salt-spray environment was found to pose a more serious effect on FMLs than the hygrothermal environment. The addition of GNPs at 0.3 wt% effectively reduced the water absorption of FMLs by 57.6% whilst improving their impact resistance by 150.6% in comparison with pure FML in the case of treatment by the salt-spray environment. The water absorption reduction is caused by GNPs creating a tortuous path for diffusion of water molecules and restricting the intermolecular motion of the epoxy molecules. The impact resistance improvement can be attributed to GNPs improving the modulus and crack-resistance of the epoxy matrix and thus the interfacial bonding of FMLs. Refereed/Peer-reviewed

Highly efficient extraction of uranium from seawater is vital for meeting the growth demands of uranium resources for the development of nuclear energy industry. However, currently available uranium adsorbents encounter multiple challenges, including the ultralong extraction period, severe marine biofouling, and violent impact of ocean motions. Targeting on these challenges and inspiring by the high tolerance of kelp to marine biofouling and motions, a kelp inspired super-toughness (KIST) bio-hydrogel is fabricated for uranium extraction from seawater. The hydrogel KIST is prepared by compositing the biofriendly and low-cost bacterial cell debris with polyvinyl alcohol, making the KIST hydrogel possesses high environment friendly. Attributing to the fast uranium adsorption rate of the bacterial cell debris, the KIST hydrogel realizes a uranium extraction capacity of 1.18 mg g−1 in biofouling-containing natural seawater with an ultrafast equilibrium adsorption time of 28 h, which is the shortest among all available uranium adsorbents in natural seawater. The antimicrobial activity of the bacterial cell debris empowers KIST hydrogel with as high as 99.21% inhibition rate to the growth of a broad range marine biofouling microorganisms, including the marine bacteria and marine algae. The KIST hydrogel also possesses outstanding tensile ability, flexibility, and rheological property, endowing the hydrogel with high resistance to the ocean current. Taking into consideration these advantages, the KIST hydrogel would be a promising adsorbent for practical uranium extraction.

Two-dimensional (2D) materials have attracted great attention recently. SnS/SnS2 with sheet-like morphologies are widely used in photoelectric devices because of their excellent electronic transpor...

This paper presents the design of stretchable elastomer-liquid metal capacitors fabricated with mechanical isolation structures. We envision potential application to stretchable and strain stable devices such as chemical sensors, as well as temperature compensation in soft sensors. A strength of the employed isolation approach is the ability to fabricate strain sensitive and strain isolated capacitors in the same substrate. A finite element model is presented, and the responses to $x$ -axis strain, $y$ -axis strain, and temperature are characterized. The capacitor with a labyrinth isolation structure shows a five-fold reduction in $x$ -axis strain response over a capacitor without isolation. Co-fabricated strain sensitive and strain isolated capacitors show a factor-of-four reduction in temperature response over the strain sensitive capacitor, demonstrating potential applications as a temperature compensated and stretchable strain or pressure sensors.

SnS nanobelt thin films were deposited on glass substrates in acidic solution by chemical bath deposition (CBD) method. The belt-like morphologies of as-deposited SnS thin films were characterized by scanning electron microscope (SEM) and transmission electron microscopy (TEM). X-ray diffraction (XRD) and Raman measurements were carried out to confirm the crystal structures and phase purities of SnS nanobelt thin films. The morphologies and phase purities of SnS thin films were influenced greatly by the tin and sulfur precursors. The bandgaps of SnS nanobelts were determined to be 1.39–1.41 eV by UV–vis absorption and photoluminescence (PL) spectra. Current-voltage ((I V)) and current-time ((I-T)) characteristics were studied to demonstrate the photoelectric performances of SnS nanobelt thin films.

The multi-thermal fluid process is a new technology that was generated for the development of offshore heavy oil. It has achieved remarkable results in the development of Bohai Oilfield. However, the mechanism of enhanced oil recovery still requires further discussion. Based on the physical similarity criterion, a physical simulation experimental device was independently designed to execute laboratory experiments on different thermal recovery methods (hot water, steam, and multi-thermal fluid), after which the contents of the four components of developed heavy oil were measured and analyzed. The results of the physical simulation experiments indicated that: (1) Thermal viscosity reduction and thermal expansion are the principle mechanisms of hot water flooding; (2) Thermal viscosity reduction and steam distillation are the principle mechanisms of steam flooding, which are accompanied by a certain degree of aquathermal cracking reaction between heavy oil and steam; and (3) thermal viscosity reduction and aquathermal cracking reaction are the principle mechanisms of multi-thermal fluid flooding. Due to the synergistic effect of nitrogen and carbon dioxide, the effect of viscosity reduction by the dissolution effect and gas-water hybrid drive must also be considered. The analysis results of the four components of developed heavy oil by the different thermal recovery methods indicated that the multi-thermal fluid changed the balance of the aromatics-asphaltene-resin regime and strengthened the development degree of the asphaltene component in heavy oil, thereby improving oil recovery through the thermal/physical/chemical mechanism.

High quality polycrystalline CdZnTe (CZT) films were prepared on GaN substrates via close-spaced sublimation (CSS). Au electrodes were deposited on the surface of CZT films to form CZT/Au structure. XRD, SEM, EDAX and UV-Vis spectra were adopted to investigate the structure, composition and morphology of CZT films. XPS and I-V characterizations were used to investigate the surface defects and electrical properties of CZT films. The quantity of the surface defects is decreased with the extended growth times and remains stable when the deposition times exceed 20 min. The minimum resistivity of CZT thick films grown on GaN substrates is 1.12 × 109 Ω-cm, which is about two orders of magnitude higher than that on FTOs. The high resistivity can significantly reduce the leakage currents of CZT films and thus improve the signal-to-noise ratio of the radiation detector based on CZT films.

Aquathermolysis is an important approach to in situ conversion, a form of heavy oil thermal recovery technology. The aquathermolysis reaction models for high-sulfur heavy oil previously proposed by scholars are not suitable for low-sulfur heavy oil. Additionally, the essence of an aquathermolysis reaction is the change in the heavy oil composition, which cannot be characterized by existing models. To address these two problems, we established an aquathermolysis model for low-sulfur heavy oil, which can characterize the composition change. This model is based on material balance, reaction kinetics, and the Arrhenius equation and includes the aquathermolysis equation, the reaction kinetics model, and the Gaussian reaction rate model. We compared results of the modified model with an experimental model and found the following: (1) The characteristics of aquathermolysis of low-sulfur heavy oil were in accordance with its Gaussian type, (2) the model could predict the composition change of heavy oil more accurately and could more precisely predict the gas reaction rate of low-sulfur heavy oil, and (3) the model has a common applicability for low-sulfur heavy oil of different viscosities.

In this work, a large number of experiments have been carried out to study the aquathermolysis of heavy oil of different viscosities with superheated steam. First, a high-temperature and high-pressure autoclave was independently designed to carry out an aquathermolysis reaction with superheated steam. Second, the viscosities of the heavy oil samples were measured before and after the aquathermolysis reaction by an MCR 302 rheometer. Finally, both the saturates, aromatics, resins, and asphaltenes (SARA) content and the carbon number distribution of heavy oil samples before and after the aquathermolysis reaction were determined by chromatography. The experimental results show the following: (1) The higher the content of resins and asphaltenes, the longer is the reaction time for aquathermolysis equilibrium. (2) As for different viscosity oil samples, the starting temperature for aquathermolysis is different; however, the reaction temperature for aquathermolysis equilibrium is the same. (3) The cracking of r...

The modeling of thermal fluid (mostly reported for saturated steam) flow in wells involving steady-state heat transfer inside wellbores and transient heat transfer in sea water or formation is reviewed and inherited. It is a good addition of modeling of supercritical/superheated fluid to the existing body of literature. The flow of supercritical CO2 coupled with superheated water (SHW) in offshore wells is described by means of the differential mass, energy and momentum balance equations along the vertical wellbores. The effect of supercritical CO2 on pressure and temperature of the multi-component thermal fluid is expressed in terms of the real gas model (the S-R-K model). The differential equations are solved with finite difference method on space involving the constant injection parameters at wellhead. It is found out that: (a). while seawater has a significant influence on temperature drop in wellbores, its effect on pressure profiles is weak. (b). both temperature and superheat degree decrease with increasing of the content of supercritical CO2. Besides, study of the effect of injection rate and pressure is conducted.

The injection of supercritical CO2 coupled with superheated steam (SHS) for heavy oil recovery can improve development efficiency. In order to help oil fields to improve the efficiency of CO2 and SHS utilization we must predict the thermophysical properties at well bottom. Based on the mass, energy, and momentum conservation equations, a non‐isothermal pipe‐flow model is established considering heat exchange between the integral joint tubing (IJT) and annuli. Coupled with the transient thermal conduction model in stratum and the S‐R‐K real gas model, a comprehensive model is established for the mixture flow in concentric dual‐tubing wells (CDTW). The model is solved by a numerical method and an iteration technique. The results show that: (a) the accuracy of the temperature profile calculation has been greatly improved compared with the previous model; (b) the heat‐carrying capacity per unit mass of the mixture and heating efficiency decrease with increasing supercritical CO2 content; (c) when a temperature difference exists between the IJT and annuli, a rapid flow of thermal energy exists inside the CDTW, which causes a significant temperature change near the wellbore, but the influence of temperature change on pressure profiles is negligible. © 2018 Society of Chemical Industry and John Wiley & Sons, Ltd.

To obtain multi-functional β-iPP composites, β-iPP composites are always filled by multiple fillers with α-nucleating ability. To prepare β-iPP/TiO2/MMT composites, TiO2-supported MMT with a β-nucleating surface was prepared through hydrolysis reaction of Tetra-n-butyl titanate and chemical reaction between pimelic acid and calcium ion. X-ray diffraction and scanning electron micrograph confirmed the formation of TiO2 on the surface of MMT. The differential scanning calorimeter and X-ray diffraction illustrated that the β-iPP composites filled by TiO2 and MMT had lower relative β-phase contents than β-iPP. It is observed by polarized optical microscope that addition of TiO2-supported MMT with a β-nucleating surface into iPP can increase the spherulite nuclei density and decrease the spherulite size significantly and obtain the β-iPP/TiO2/MMT composites with high relative β-phase content.

ZnO (Zinc oxide)/Si (Silicon) heterojunctions were prepared by depositing n-type ZnO films on p-type single crystal Si substrates using magnetron sputtering. A boron and gallium co-doped ZnO (BGZO) high conductivity intermediate layer was deposited between aurum (Au) electrodes and ZnO films. The influence of the BGZO layer on the properties of Au/ZnO contacts and the performance of ZnO/Si heterojunctions was investigated. The results show an improvement in contact resistance by introducing the BGZO layer. Compared with the ZnO/Si heterojunction, the BGZO/ZnO/Si heterojunction exhibits a larger forward current, a smaller turn-on voltage and higher ratio of ultraviolet (UV) photo current/dark current.

In this paper, SnS nanotubes are firstly prepared in acidic solution by template free electrodeposition method at room temperature. The morphological evolution and photoelectrochemical properties of SnS nanotubes are investigated. X-ray diffraction (XRD), energy dispersive X-ray spectrometry (EDS) and Raman spectra measurements examine the phase purities of deposited SnS thin films. Scanning electron microscopy (SEM) and transmission electron microscopy (TEM) characterizations indicate morphological properties of SnS nanotubes. The band-gap of SnS nanotubes is confirmed by UV–Vis-NIR diffuse reflection spectra. The photoelectrochemical measurements show that the photocurrent density of FTO/SnS nanotubes is about 31 μA/cm2 and maximum IPCE value of SnS nanotubes is 7.4%.

SnS nanosheet thin films were prepared by chemical bath deposition in acidic solution, which used tin (II) chloride dihydrate and thioacetamide as precursors of Sn and S, respectively. The influences of pH levels, precursors' mole ratios, deposition times on the physical properties of SnS nanosheet thin films were investigated. The sheet-like morphologies and compositions of as-deposited SnS thin film were characterized by Scanning electron microscope (SEM). X-ray diffraction (XRD), Raman and X-ray photoelectron spectra (XPS) were used to confirm the crystal structures and phase purities of SnS nanosheet thin films. When employed as a photocathode for photo-electrochemical (PEC) solar hydrogen production, the as-deposited SnS nanosheet thin films yielded photocurrent densities of 31.94 μA cm−2 at −0.4 V under illumination of AM 1.5G. After deposition of CdS and Pt layers, the cathodic photocurrent densities of FTO/SnS/CdS/Pt and FTO/annealed SnS/CdS/Pt were improved to 0.572 mA cm−2 and 0.702 mA cm−2, respectively, which demonstrated the great potential of using earth-abundant SnS for efficient hydrogen production.

Al-rich AlN transition layers (AlN–Al) on AlN ceramic substrates (c-AlN) are as pioneering work to prepare high quality CdZnTe films. It is pronounced that the structural and electric properties of CdZnTe films based on AlN–Al are enhanced. Among all the CdZnTe films, steepest diminishment of dislocation density can be by 78.84% on the surface and maximal drop is more than quadruple for Cd vacancy on the interface, compared with no Al-rich ones. Subjected to investigation of Al on the interface by EDX and low temperature PL, AlN–Al have provided Al3+ to compensate defects in CdZnTe films, and the diffusion process of Al3+ is discussed. The amount of Al3+ at the interface of CdZnTe is on a tendency of proliferation preceding recession and the optimum is where doping content of Al in transition layers is 1 wt %. The optimal photo-dark current ratio and responsivity of CdZnTe/AlN–Al/c-AlN composites with parallel electrodes under 254 nm UV light illumination are around 369 and 10.6 mA/W, indicating a brilliant prospect of detection in solar-blind region.