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Rechargeable zinc-air batteries (ZABs) are a promising energy conversion device, which rely critically on electrocatalysts to accelerate their rate-determining reactions such as oxygen reduction (ORR) and oxygen evolution reactions (OER). Herein, we fabricate a range of bifunctional M–N–C (metal-nitrogen-carbon) catalysts containing M–Nx coordination sites and M/MxC nanoparticles (M = Co, Fe, and Cu) using a new class of γ-cyclodextrin (CD) based metal–organic framework as the precursor. With the two types of active sites interacting with each other in the catalysts, the obtained Fe@C-FeNC and Co@C-CoNC display superior alkaline ORR activity in terms of low half-wave (E1/2) potential (~ 0.917 and 0.906 V, respectively), which are higher than Cu@C-CuNC (~ 0.829 V) and the commercial Pt/C (~ 0.861 V). As a bifunctional electrocatalyst, the Co@C-CoNC exhibits the best performance, showing a bifunctional ORR/OER overpotential (ΔE) of ~ 0.732 V, which is much lower than that of Fe@C-FeNC (~ 0.831 V) and Cu@C-CuNC (~ 1.411 V), as well as most of the robust bifunctional electrocatalysts reported to date. Synchrotron X-ray absorption spectroscopy and density functional theory simulations reveal that the strong electronic correlation between metallic Co nanoparticles and the atomic Co-N4 sites in the Co@C-CoNC catalyst can increase the d-electron density near the Fermi level and thus effectively optimize the adsorption/desorption of intermediates in ORR/OER, resulting in an enhanced bifunctional electrocatalytic performance. The Co@C-CoNC-based rechargeable ZAB exhibited a maximum power density of 162.80 mW cm−2 at 270.30 mA cm−2, higher than the combination of commercial Pt/C + RuO2 (~ 158.90 mW cm−2 at 265.80 mA cm−2) catalysts. During the galvanostatic discharge at 10 mA cm−2, the ZAB delivered an almost stable discharge voltage of 1.2 V for ~ 140 h, signifying the virtue of excellent bifunctional ORR/OER electrocatalytic activity.

In this work, the closing process of aerial self-locking nuts with different materials was simulated using static analysis in Abaqus/Standard. The effects of different closing amounts of self-locking nuts with different types on the locking performance of self-locking nuts were investigated. In order to analyze the locking performance of self-locking nuts, the method was measured by using the maximum equivalent stress on the root of the third thread. Finally, the equivalent stress range of self-locking nuts of different materials and the closing size range of self-locking nuts of different types were obtained. The equivalent stress ranges of TC4, GH2132 and GH4169 self-locking nuts were 1060–1090 MPa, 664–712 MPa and 860–920 MPa, respectively. At the same time, the corresponding closing amount of M5-M10 self-locking nuts is 0.22–0.46 mm, 0.37–0.64 mm and 0.43–0.75 mm, respectively. (The simulation results show that the equivalent stress of different types of self-locking nuts with the same material shows the characteristics of layered distribution. The equivalent stress of the same type of self-locking nut increases with the increase of the closing amount. When the closing amount is the same, the smaller the type of the nut, the greater the equivalent stress. For the same of the equivalent stress, the closing amount increases with the increase of the type of self-locking nuts.) The conclusions can provide a reasonable theoretical reference for the closing process of aerial self-locking nuts with different materials.

In this work, the thermal stability issue of ultrathin Ti-based silicide (TiSix) in prospective dynamic random access memory (DRAM) peripheral 3D FinFET transistors was systematically studied. As-prepared TiSix/n+-Si contacts and ultrathin TiSix films with different annealing temperatures, were characterized by means of specific contact resistivity (ρc), sheet resistance measurement, X-ray diffraction (XRD), transmission electron microscopy (TEM) and energy-dispersive X-ray spectroscopy (EDX). It is shown that the specific contact resistivity (ρc) for TiSix/n+-Si contacts gradually degrades with the increase of annealing temperature in the range 450–900 °C. In addition, it is revealed that though thick TiSi2 is conventionally known as thermal stable silicide, the agglomeration of ultrathin TiSix in the source/drain regions of 3D FinFETs still occurs after DRAM annealing typically at 750 °C for few hours. This agglomeration is thought to be responsible for the deterioration of ρc for TiSix/n+-Si contacts.

Calcium carbonate is promising thermochemical heat storage material for next-generation solar power systems due to its high energy storage density, low cost, and high operation temperature. Researchers have tried to improve energy storage performances of calcium carbonate recently, but most researches focus on powders, which are not suitable for scalable applications. Here, novel granular porous calcium carbonate particles with very high solar absorptance, energy storage density, abrasive resistances, and energy storage rate are proposed for direct solar thermochemical heat storage. The average solar absorptance is improved by 234% compared with ordinary particles. Both cycle stability and abrasive resistances are excellent with almost no decay of energy storage density over 25 cycles nor apparent particle weight loss over 24 h of continuous operation insides a planetary ball mill. In addition, the decomposition temperature is reduced by 2.8%–5.6% while the reaction rate of heat storage is enhanced by 80%–205% depending on the CO2 partial pressure. The decomposition process of doped granular porous CaCO3 particles is found to involve three overlapping processes. This work provides new routes to achieve scalable direct solar thermochemical heat storage for next-generation high-temperature solar power systems.

With the wide application of laser technology in laser processing and photoelectric detection, the measurement and display of the laser beam polarization has become an extremely important prerequisite. In this paper, we realize the laser polarization measurement tool based on the virtual instrument LabVIEW software platform. The set-up is designated to measure the Stokes parameters for an arbitrarily polarized beam, using the rotating waveplate method provided by the stepper motor, drive circuit, photodetector, and computer processing of the digitized electrical signal in the PCI expansion card. The Poincare sphere is used for the interpretation of the state of polarization (SOP) and degree of polarization (DOP). The working wavelength range is declared to be 400 – 1100 nm, the accuracy of DOP, azimuth measurement, and ellipticity are ±2%, 0.4°, and 0.4°, respectively.

In this paper, we propose a measurement system based on single autocorrelation technology and combined with LabVIEW software platform to realize the real-time online measurement of the femtosecond-laser pulse width. The system uses an experimental device based on the Mach–Zehnder interferometer, where the second-harmonic signal of femtosecond laser is obtained by the nonlinear effect of light and nonlinear material; the linear grayscale conversion, median filtering, and threshold segmentation are also applied to the second-harmonic signal. The image centroid, autocorrelation curve, and femtosecond-laser pulse width are obtained, using LabVIEW software. In the experiment, a seed laser source with a central wavelength of 800 nm is used as a test object, and the pulse width is measured to be equal to 261 fs.

In this work, a selective wet etching process of Si to Si0.7Ge0.3 with TMAH solution to fabricate SiGe nanowires is systematically investigated. Initially, the 2.3% TMAH solution at 20 °C is applied for the as grown Si0.7Ge0.3/Si multilayers stack and a “rectangular” profile is achieved at the Si0.7Ge0.3 extremity due to its high selectivity. However, the reduction of Ge concentration due to the Ge interdiffusion caused by the high temperature anneal treatment will attain a reduced selectivity of Si to Si0.7Ge0.3 and a “rounding” Si0.7Ge0.3 extremity profile. Moreover, the profile of the upper Si0.7Ge0.3 extremity is clearly worse than the bottom one. This is because the Ge concentration of upper Si0.7Ge0.3 is 1.5% lower and the Ge interdiffusion of the upper Si0.7Ge0.3 is slightly worse. After increasing the TMAH concentration to 25%, both the upper and bottom Si0.7Ge0.3 extremity can achieve a “rectangular” extremity profile with an almost the same Si0.7Ge0.3 loss ~ 1.5 nm per side. Compared with 2.3% TMAH concentration, the Ge concentration of the etching off SiGe film can be reduced from lower than 29% to lower than 24% using the 25% TMAH solution at 20 °C. Therefore, the 25% TMAH solution at 20 °C is chosen as the optimal selective etching condition for the thermal treated Si0.7Ge0.3/Si multilayers stack samples. Finally, a vertical stacked double SiGe nanowire structure is successfully prepared by utilizing this optimal process condition. This indicates that it is a practicable technique for the selective wet etching of Si in fabricating SiGe nanowires.

We study a continuous-wave sum-frequency blue laser operating at 484 nm. The laser elaborated is based on the intracavity pumping technology. A 912 nm laser produced by an end-pumped Nd:GdVO4 crystal, using an 808 nm fiber-coupled laser diode, is employed to pump an Yb:YAG crystal in the cavity to achieve the simultaneous oscillations in 912 and 1030 nm lasers. An intracavity sum-frequency achieved in a type-I phase-matched BIBO crystal is used to obtain the 484 nm blue laser output. In our experiment, we apply a linear coaxial laser resonator structure. As a result, we obtain a sumfrequency blue laser output of 317 mW at a pump power of 25 W. The slope efficiency of the designed laser is 2.8%, and the beam quality factors are 1.34 in the X direction and 1.36 in the Y direction, respectively, with the power fluctuations about 3.8% within four hours.

There is great variation in the lithology and lamination thickness of composite roof in coal-measure strata; thus, the roof is prone to delamination and falling, and it is difficult to control the surrounding rock when developing roadway in such rock strata. In deep mining, the stress environment of surrounding rock is complex, and the mechanical response of the rock mass is different from that of the shallow rock mass. For composite-roof roadway excavated in deep rock mass, the key to safe and efficient production of the mine is ensuring the stability of the roadway. The present paper obtains typical failure characteristics and deformation and failure mechanisms of composite-roof roadway with a buried depth of 650 m at Zhaozhuang Coal Mine (Shanxi Province, China). On the basis of determining a reasonable cross-section shape of the roadway and according to the failure characteristics of the composite roof in different regions, the roof is divided into an unstable layer, metastable layer, and stable layer. The controlled unstable layer and metastable layer are regarded as a small structure while the stable layer is regarded as a large structure. A superimposed coupling support technology of large and small structures with a multi-level prestressed bearing arch formed by strong rebar bolts and highly prestressed cable bolts is put forward. The support technology provides good application results in the field. The study thus provides theoretical support and technical guidance for ground control under similar geological conditions.

2 μm/3 μm laser has been extensively applied to the fields of medical treatment, communication and detection. In this paper, the genetic algorithm is innovatively used to solve the fiber power transmission equation, which improves the accuracy of simulation results. According to the simulation results, a dual-wavelength Er3+:ZBLAN fiber laser based on composite Fabry-Perot (F-P) cavity was designed and constructed. A stable continuous dual-wavelength output was obtained with a pump power of 50 W. The center wavelengths were 2.79 μm and 1.59 μm, respectively, the maximum output powers were 8.19 W and 2.8 W, respectively, the slope efficiencies were 17.7% and 7.17%, respectively, and the stability of the wavelengths in 2 h were 4.6% and 3.1%, respectively.

In this work, SiGe Fin formation technique using shallow trench isolation (STI) first or STI last strategy for the high mobility channel FinFET device is systematically investigated. A 20 nm width and 35 nm height high crystalline quality of the Si0.7Ge0.3 Fin formation for STI first scheme is demonstrated by utilizing a new developed Si Fin etching, Si Fin recess and SiGe selective epitaxial growth process. For the STI last strategy, a novel chemical mechanical planarization (CMP) treated three-layer SiGe strain relaxed buffer (SRB) is successfully fabricated and a 50 nm high crystal quality and atomically smooth surface Si0.5Ge0.5 layer on this SRB is attained. Moreover, a spike annealing is employed to avoid the Si0.5Ge0.5 Fin oxidation during STI densification with an acceptable STI etching rate. However, both a spike annealing and a lower temperature of traditional furnace at 850 °C or 750 °C suffer micro-trench issue during the Fin reveal process. Therefore, a new developed process, named as STI recess first, is developed to resolve both thermal instability and micro-trench issue at the same time. A minor Si0.5Ge0.5 Fin loss with a sharp Si0.7Ge0.3 SRB/Si0.5Ge0.5 interfaces for STI last scheme is realized by utilizing this new developed STI recess first process.

Carbon capture is widely recognised as an essential strategy to meet global goals for climate protection. Although various CO2 capture technologies including absorption, adsorption and membrane exist, they are not yet mature for post-combustion power plants mainly due to high energy penalty. Hence researchers are concentrating on developing non-aqueous solvents like ionic liquids, CO2-binding organic liquids, nanoparticle hybrid materials and microencapsulated sorbents to minimize the energy consumption for carbon capture. This research aims to develop a novel and efficient approach by encapsulating sorbents to capture CO2 in a cold environment. The conventional emulsion technique was selected for the microcapsule formulation by using 2-amino-2-methyl-1-propanol (AMP) as the core sorbent and silicon dioxide as the shell. This paper reports the findings on the formulated microcapsules including key formulation parameters, microstructure, size distribution and thermal cycling stability. Furthermore, the effects of microcapsule quality and absorption temperature on the CO2 loading capacity of the microcapsules were investigated using a self-developed pressure decay method. The preliminary results have shown that the AMP microcapsules are promising to replace conventional sorbents.

On approach towards the end of technology roadmap, a revolutionary approach towards the nanowire transistors is favorable due to the full control of carrier transport. The transistor design moves toward vertically or laterally stacked Gate-All-Around (GAA) where Si or SiGe can be used as channel material. This study presents a novel isotropic inductively coupled plasma (ICP) dry etching of Si1−xGex (0.10 ≤ x ≤ 0.28) in SiGe/Si multilayer structures (MLSs) with high selectivity to Si, SiO2, Si3N4 and SiON which can be applied in advanced 3D transistors and Micro-Electro-Mechanical System (MEMS) in future. The profile of SiGe etching for different thicknesses, compositions and locations in MLSs using dry or wet etch have been studied. A special care has been spent for layer quality of Si, strain relaxation of SiGe layers as well as residual contamination during the etching. In difference with dry etching methods (downstream remote plasma), the conventional ICP source in situ is used where CF4/O2/He gas mixture was used as the etching gas to obtain higher selectivity. Based on the reliability of ICP technique a range of etching rate 25–50 nm/min can be obtained for accurate isotropic etching of Si1−xGex, to form cavity in advanced 3D transistor processes in future.

Aiming at the problem of mining coal resources under the Yuxing Mine Ecological Park in Inner Mongolia, China, we adopted a continuous mining and continuous backfilling (CMCB) cemented-fill mining method; based on the systematic description of the mining and backfilling craft of the CMCB mining process, comprehensive use of theoretical analysis, numerical simulation, and similar simulation test methods to analyze the control mechanism of overlying strata. By establishing the mechanical model of roof movement for the CMCB mining, the roof deflection curve equation is deduced, and the roof instability criterion is put forward based on the maximum tensile stress criterion. Numerical simulation showed that the stress curve at the shallow part of the roof fluctuates up and down in a “w” shape, the stress curve of the upper surrounding rock sinks slowly, and the coal pillars and filling bodies are alternately loaded during the staged mining process to jointly limit the movement of the overlying strata. The similar simulation test results showed that the roof has no structural damage, the roof cracks are not obvious, and the overlying strata control effect is good. On site tests showed that the CMCB mining method can effectively limit the movement of the overlying rock in the stope, control the surface subsidence of the ecological park, and increase the recovery rate of coal resources. It can provide a reference for the development of coal resources and ecological protection in a fragile environment.

Background The C2H2-type zinc finger proteins (C2H2-ZFPs) are one of major classes of transcription factors that play important roles in plant growth, development and stress responses. Limit information about the C2H2-ZF genes hinders the molecular breeding in bread wheat (Triticum aestivum). Results In this study, 457 C2H2-ZFP proteins (including 253 splice variants), which contain four types of conserved domain (named Q, M, Z, and D), could be further classified into ten subsets. They were identified to be distributed in 21 chromosomes in T. aestivum. Subset-specific motifs, like NPL-, SFP1-, DL- (EAR-like-motif), R-, PL-, L- and EK-, might make C2H2-ZFP diverse multifunction. Interestingly, NPL- and SFP1-box were firstly found to be located in C2H2-ZFP proteins. Synteny analyses showed that only 4 pairs of C2H2 family genes in T. aestivum, 65 genes in B. distachyon, 66 genes in A. tauschii, 68 genes in rice, 9 genes in Arabidopsis, were syntenic relationships respectively. It indicated that TaZFPs were closely related to genes in Poaceae. From the published transcriptome data, totally 198 of 204 TaC2H2-ZF genes have expression data. Among them, 25 TaC2H2-ZF genes were certificated to be significantly differentially expressed in 5 different organs and 15 different development stages by quantitative RT-PCR. The 18 TaC2H2-ZF genes were verified in response to heat, drought, and heat & drought stresses. According to expression pattern analysis, several TaZFPs, like Traes_5BL_D53A846BE.1, were not only highly expressed in L2DAAs, RTLS, RMS, but also endowed tolerance to drought and heat stresses, making them good candidates for molecular breeding. Conclusions This study systematically characterized the TaC2H2-ZFPs and their potential roles in T. aestivum. Our findings provide new insights into the C2H2-ZF genes in T. aestivum as well as a foundation for further studies on the roles of TaC2H2-ZF genes in T. aestivum molecular breeding.

A form stable NaCl-Al2O3 (50–50 wt-%) composite material for high temperature thermal energy storage was fabricated by cold sintering process, a process recently applied to the densification of ceramics at low temperature 300°C under uniaxial pressure in the presence of small amount of transient liquid. The fabricated composite achieved as high as 98.65% of the theoretical density. The NaCl-Al2O3 composite also retained the chloride salt without leakage after 30 heating-cooling cycles between 750°C–850°C together with a holding period of 24 h at 850°C. X-ray diffraction measurements indicated congruent solubility of the alumina in chloride salt, excellent compatibility of NaCl with Al2O3, and chemical stability at high temperature. Structural analysis by scanning electron microscope also showed limited grain growth, high density, uniform NaCl distribution and clear faceted composite structure without inter-diffusion. The latent heat storage density of 252.5 J/g was obtained from simultaneous thermal analysis. Fracture strength test showed high sintered strength around 5 GPa after 50 min. The composite was found to have fair mass losses due to volatilization. Overall, cold sintering process has the potential to be an efficient, safe and cost-effective strategy for the fabrication of high temperature thermal energy storage materials.

In this work, a novel three-layer SiGe strain relaxed buffer/strained Si0.5Ge0.5 layer stacking structure is systematically investigated. The novel three-layer graded SiGe strain relaxed buffer, whose Ge concentration increased from bottom to top by roughly 10% with an in situ annealing after each layer grown, can effectively constrain the threading dislocation in the strain relaxed buffer layer. Moreover, a chemical mechanical planarization process can be applied to the strain relaxed buffer to further improve its surface roughness. A high crystal quality and atomically smooth surface Si0.5Ge0.5 layer can be successfully realized on the novel chemical mechanical planarization-treated three-layer SiGe strain relaxed buffer. This strategy can attain at least 50 nm and 0.6% compressive strained Si0.5Ge0.5 layer and its quantification of the strain level is confirmed by utilizing the scanning moire fringe imaging technique. It can be seen that this novel structure can provide a better mobility and larger width for the FinFET or nanowire SiGe channel device.

Scaling of interconnect dimensions is becoming increasingly difficult due to the fast rise in line/via resistance. To alleviate this problem, Co is a high-potential alternative material of Cu or W in metallization schemes. In this work, Co interconnects is imitated, where Co1−xTix is proposed as single barrier/liner to replace conventional thick TiN/Ti bilayer structure, reserving more available space for interconnect metal to achieve overall lower line resistance. The samples with and without Co1−xTix or TiN metal capping were fabricated in attempt to optimize the whole interconnects. Meanwhile, the properties of these films with different stacking structures were comprehensively studied through material analysis instruments. In order to further evaluate the barrier ability of Co1−xTix single layer, the capacitance–voltage (C–V) and current–voltage (I–V) characteristics of MOS capacitors after thermal stress (TS) as well as bias thermal stress (BTS) were analyzed elaborately. Obtained results indicate that Co1−xTix single barrier/line is effective to enhance adhesion property and to restrain Co diffusion into SiO2 dielectric, and TiN metal capping is also indispensable for Co interconnects to improve thermal stability and to prevent Co oxidation.

The aggressive shrinkage of contact size unfortunately leads to significant increase of interconnect resistance, especially the irreducible resistance of M0 and/or M1 where thick functional TiN/Ti barrier/liner bilayer occupies too much space of interconnecting metal. In this circumstance, the pursual of alternative barrier/liner working properly is becoming a hot spot. Amorphous Co–Ti alloying film is considered as an active single barrier/liner to replace conventional thick TiN/Ti bilayer structure, achieving lower resistance of interconnects. In this work, the dedicated material properties of Co–Ti films with various content of Ti (from pure Co to pure Ti) are investigated systematically. As-fabricated Co–Ti films were comprehensively characterized in terms of crystalline structure, sheet resistance, surface and interfacial morphology as well as composition using X-ray diffraction, four-probe measurement, scanning electron microscope, and transmission electron microscopy in conjunction with energy-dispersive X-ray spectroscopy and electron energy loss spectroscopy respectively. Obtained results show that taking the low resistivity, thermal stability and Ti segregation at both Co/Co1−xTix and Co1−xTix/SiO2 interface after annealing at 500 °C/30 min into account, the amorphous Co0.75Ti0.25 film is the most proper composition as a single barrier/liner.

The laser source with 3 μm/2 μm output wavelength has many application prospects in clinical medicine, photoelectric countermeasure, and scientific research measurement. An Er3+ doped ZBLAN fiber laser with output wavelength of 2 .8 μm and 1 .6 μm is experimentally studied. By setting the pump power to 5 W, a continuous dual-wavelength output with a central wavelength of 2.803 μm and 1.61 μm is obtained and the corresponding maximum output power is 362.4 mW and 108.6 mW. The slope efficiency is 12.1% and 4.94% respectively. What’s more, the slope efficiency is 12.1% and 4.94% respectively, and the fluctuation rates of peak power of the two wavelengths are 9.7% and 2.1% within 4 h which indicate that the laser has relatively good stability.

Protein-protein interactions (PPIs) are critical for cellular activity regulation. Visualization of PPIs using bimolecular fluorescence complementation (BiFC) techniques helps to understand how PPIs implement their functions. However, current BiFC is based on fluorescent proteins and the brightness and photostability are suboptimal for single molecule tracking experiments, resulting in either low spatiotemporal resolution or incapability of tracking for extended time course. Here, we developed the TagBiFC technique based on split HaloTag, a self-labeling tag that could conjugate an organic dye molecule and thus offered better brightness and photostability than fluorescent proteins for PPI visualization inside living cells. Through screening and optimization, we demonstrated that the reconstituted HaloTag exhibited higher localization precision and longer tracking length than previous methods. Using TagBiFC, we reveal that the dynamic interactions of transcription factor dimers with chromatin DNA are distinct and closely related to their dimeric states, indicating a general regulatory mechanism for these kinds of transcription factors. In addition, we also demonstrated the advantageous applications of TagBiFC in single nucleosome imaging, light-burden imaging of single mRNA, low background imaging of cellular structures. We believe these superior properties of our TagBiFC system will have broad applications in the studies of single molecule imaging inside living cells., Shao et al. develop an imaging probe, TagBiFC, to visualize protein-protein interaction in living cells with better signal-to-noise ratio and photostability than fluorescent proteins. This probe provides better localization and longer tracking time and authors visualise transcription factor dimerization, single-molecule nucleosome, and background-free mRNA imaging using TagBiFC.

We combine experimental data, FLAC3D numerical simulation results, and on-site industrial tests to study the problem of coal pillar size design in longwall entry. The Zhaozhuang coal mine located in Changzhi City, Shanxi Province, China, is used as a case study. We use an inversion calculation of the double-yield constitutive model to improve the reliability of the simulation results. Calculated results are fitted using a theoretical value of the Salamon strength formula to obtain mechanical parameters of the rock mass in the goaf, which are used to numerically simulate its compaction-bearing characteristics. The stress distribution state and plastic zone failure characteristics of entry surrounding rock under different coal pillar widths during mining are obtained by numerical calculation. The results show that increased coal pillar size leads to a gradual shift of the peak stress from the solid coal side to the coal pillar side. Use of an 8-m coal pillar generates a lower stress environment and has sufficient bearing capacity to remain stable. Based on the results obtained here, we propose differentiated support techniques that address the differential deformation and stress distribution of surrounding rock both sides of the goaf-side entry. On-site industrial tests show that the proposed support technology effectively reduces the deformation variation and ensures safe entry use during servicing.

Background Organ replacement regenerative therapy based on human adult stem cells may be effective for salivary gland hypofunction. However, the generated tissues are immature because the signaling factors that induce the differentiation of human salivary gland stem cells into salivary glands are unknown. Methods Isolated human submandibular gland stem/progenitor cells (hSMGepiS/PCs) were characterized and three-dimensionally (3D) cultured to generate organoids and further induced by fibroblast growth factor 10 (FGF10) in vitro. The induced spheres alone or in combination with embryonic day 12.5 (E12.5) mouse salivary gland mesenchyme were transplanted into the renal capsules of nude mice to assess their development in vivo. Immunofluorescence, quantitative reverse transcriptase-polymerase chain reaction, calcium release analysis, western blotting, hematoxylin–eosin staining, Alcian blue–periodic acid-Schiff staining, and Masson’s trichrome staining were performed to assess the structure and function of generated tissues in vitro and in vivo. Results The isolated hSMGepiS/PCs could be long-term cultured with a stable genome. The organoids treated with FGF10 [FGF10 (+) group] exhibited higher expression of salivary gland–specific markers; showed spatial arrangement of AQP5+, K19+, and SMA+ cells; and were more sensitive to the stimulation by neurotransmitters than untreated organoids [FGF10 (−) group]. After heterotopic transplantation, the induced cell spheres combined with mouse embryonic salivary gland mesenchyme showed characteristics of mature salivary glands, including a natural morphology and saliva secretion. Conclusion FGF10 promoted the development of the hSMGepiS/PC-derived salivary gland organoids by the expression of differentiation markers, structure formation, and response to neurotransmitters in vitro. Moreover, the hSMGepiS/PCs responded to the niche in mouse embryonic mesenchyme and further differentiated into salivary gland tissues with mature characteristics. Our study provides a foundation for the regenerative therapy of salivary gland diseases.

The Fe3+-doped TiO2 on nitrogen-doped graphene (Fe-TiO2/N-doped graphene) electrocatalyst is synthesized and employed as cathode material for Li-O2 battery. Fe-TiO2 nanoparticles show uniform dispersion on N-doped graphene with less agglomeration compared with TiO2 nanoparticles. The improvement of electrochemical performance of Fe-TiO2/N-doped graphene electrocatalyst is due to the changed electronic and structural properties, which result in forming Ti–O–Fe bonds and oxygen vacancy sites in the crystalline structure of TiO2. The Fe-TiO2/N-doped graphene electrode delivers a discharge capacity of 13,500 mA h g−1 (catalytic) and a cyclic retention of 45 cycles, which are much better compared to the pristine counterpart.

The performance of dye-sensitized solar cells (DSSCs) is critically dependent on the catalytic activity of their counter electrode (CE) materials. There are great research interests to develop alternative CE materials to replace the conventional Pt electrode. Herein, nickel cobalt sulfide (NiCo2S4, NCS) particles were prepared through sulfurization of NiCo2O4 (NCO) electrospun nanofibers. The bimetallic sulfide was used as CE for DSSC and exhibited an excellent photoenergy conversion efficiency (PCE) of 7.12%, which is higher than the dye-sensitized solar cells using NCO (5.24%) and Pt CEs (7.05%). Systematic electrochemical characterization suggests that this extraordinary performance of NCS might be related to the improved electrocatalytic ability and electrical conductivity. In view of the low-cost synthesis and outstanding electrochemical performance, the NCS counter electrode would hold great promise for applications in dye-sensitized solar cells.

Carbon verification, which can guarantee the reliability and credibility of greenhouse gas (GHG) emission data, is the most important part of the daily operations of the carbon emission right trading system. Many international institutions, countries and regions have conducted research on and have practiced carbon verification policies and systems. Through comparative analysis of the international carbon verification policies and systems, they can provide experience for Chinese unified national carbon market to start supporting carbon verification. The paper study concludes that (1) carbon verification systems developed by international institutions focus on the scientific level of verification methods; (2) carbon verification policies and systems issued by important countries and regions draw on International Standardization Organization (ISO)14064 standards based on their national conditions and focus on the scientific level and reasonableness of verification methods; (3) major international experience includes complete verification policies and systems, strict standard verification procedures, diversified verification forms and a focus on key emission sources. Based on the differences in China’s carbon emissions characteristics caused by unbalanced regional economic development and the conditions of carbon verification in seven pilot carbon trading areas, this thesis proposes the following suggestions: pushing forward the establishment of carbon verification policies and systems by accelerating legislation on climate changes; facilitating carbon verification in a coordinated manner; regulating key GHG emission sources; establishing and improving supervision on carbon verification; and intensifying international exchanges and cooperation.

A novel approach of carbonizing leaves by thermal pyrolysis with melt diffusion followed by selenium vapor deposition is developed to prepare the carbon-selenium composite cathodes for sodium-selenium batteries. The carbonized leaf possesses internal hierarchical porosity and high mass loading; therefore, the composite is applied as a binder- and current collector-free cathode, exhibiting an excellent rate capability and a high reversible specific capacity of 520 mA h g−1 at 100 mA g−1 after 120 cycles and 300 mA h g−1 even at 2 A g−1 after 500 cycles without any capacity loss. Moreover, the unique natural three-dimensional structure and moderate graphitization degree of leaf-based carbon facilitate Na+/e− transport to activate selenium which can guarantee a high utilization of the selenium during discharge/charge process, demonstrating a promising strategy to fabricate advanced electrodes toward the sodium-selenium batteries.

Nickel sulfides (NiSs) with different morphologies (nanocubes, flower-like structure, and nanospheres) have been synthesized on fluorinated tin oxide glass (FTO) substrate using a hydrothermal method, which can be used as transparent counter electrodes (CEs) for dye-sensitized solar cells (DSSCs). The morphology of NiSs can be easily tailored by using different surfactants, and the flower-like NiS structure displays remarkable electrocatalytic activity for reducing I3 −. Therefore, the flower-like NiS CE used in DSSCs generates higher photoelectric conversion efficiency (7.10 %) which is comparable with Pt (7.05 %) under the same conditions. This work paves the way for the substitution of noble metal Pt by the flower-like NiS for CE in DSSCs in the future.

To solve the problems with coronary stent implantation, coronary artery stent surface was directly modified by three-beam laser interference lithography through imitating the water-repellent surface of lotus leaf, and uniform micro-nano structures with the controllable period were fabricated. The morphological properties and contact angle (CA) of the microstructure were measured by scanning electron microscope (SEM) and CA system. The water repellency of stent was also evaluated by the contact and then separation between the water drop and the stent. The results show that the close-packed concave structure with the period of about 12 μm can be fabricated on the stent surface with special parameters (incident angle of 3°, laser energy density of 2.2 J·cm−2 and exposure time of 80 s) by using the three-beam laser at 1 064 nm, and the structure has good water repellency with CA of 120°.

Background A number of studies have shown that tooth-like structures can be regenerated using induced pluripotent stem cells and mouse embryonic stem (mES) cells. However, few studies have reported the regeneration of tooth–periodontium complex structures, which are more suitable for clinical tooth transplantation. We established an optimized approach to induce high-odontogenic potential dental epithelium derived from mES cells by temporally controlling bone morphogenic protein 4 (BMP4) function and regenerated tooth–periodontium complex structures in vivo. Methods First, immunofluorescence and quantitative reverse transcription-polymerase chain reaction were used to identify the watershed of skin and the oral ectoderm. LDN193189 was then used to inhibit the BMP4 receptor around the watershed, followed by the addition of exogenous BMP4 to promote BMP4 function. The generated dental epithelium was confirmed by western blot analysis and immunofluorescence. The generated epithelium was ultimately combined with embryonic day 14.5 mouse mesenchyme and transplanted into the renal capsules of nude mice. After 4 weeks, the tooth–periodontium complex structure was examined by micro-computed tomography (CT) and hematoxylin and eosin (H&E) staining. Results Our study found that the turning point of oral ectoderm differentiation occurred around day 3 after the embryoid body was transferred to a common culture plate. Ameloblastin-positive dental epithelial cells were detected following the temporal regulation of BMP4. Tooth–periodontium complex structures, which included teeth, a periodontal membrane, and alveolar bone, were formed when this epithelium was combined with mouse dental mesenchyme and transplanted into the renal capsules of nude mice. Micro-CT and H&E staining revealed that the generated tooth–periodontium complex structures shared a similar histological structure with normal mouse teeth. Conclusions An optimized induction method was established to promote the differentiation of mES cells into dental epithelium by temporally controlling the function of BMP4. A novel tooth–periodontium complex structure was generated using the epithelium. Electronic supplementary material The online version of this article (doi:10.1186/s13287-017-0583-5) contains supplementary material, which is available to authorized users.

The Si-Sb-ZnO composites were prepared by a chemical reduction-mechanical alloying method and were employed as anode materials for lithium-ion batteries. The electrochemical performance of the Si-Sb alloy was significantly improved by the addition of ZnO nanoparticles. Especially, the initial specific charge and discharge capacities for Si-Sb-(ZnO)0.3 composite were 845.1 and 1301.5 mAh/g, respectively, while the initial coulombic efficiency was 64.9 %. The capacity remained at 690 mAh/g after 200 cycles, and the capacity retention ratio was 81.6 %, which demonstrated excellent cycling stability and rate capability of the composite materials. Electronic supplementary material The online version of this article (doi:10.1186/s11671-015-1128-4) contains supplementary material, which is available to authorized users.

We report for the first time, to our knowledge, the diode-pumped continuous-wave (CW) thin-disk Yb3+-doped Lu2O3 (Yb:LO) laser at 1 034 nm and the second-harmonic generation at 517 nm. With a 6.3% output coupler, the maximum output power is 1.17 W under a pump power of 18.5 W. Moreover, the intracavity second-harmonic generation (SHG) is also achieved with power of 193 mW at 517 nm by using an LiB3O5 (LBO) nonlinear crystal. The beam quality factor M2 is about 1.28. The fluctuation of the output power is about 3% in 1 h.

Vinyl chloride (VC) is a human carcinogen known to undergo metabolism by cytochrome P450 2E1 (CYP2E1) to reactive intermediates that can cause oncogene and tumor suppressor gene mutations and that are further metabolized by acetaldehyde dehydrogenase (ALDH2) and glutathione-S-transferases (GSTs) to non-mutagenic end products. These metabolic enzymes have known polymorphisms that could lead to increased levels of the VC reactive intermediates and thus an increased risk for mutations and cancer following exposure. Using restriction fragment length polymorphism (RFLP) analysis, we have examined a cohort of 597 French VC workers for polymorphisms in CYP2E1, ALDH2, GSTM1 and GSTT1 in relation to the occurrence of mutant oncogene and tumor suppressor gene biomarkers that are attributable to VC exposure. The presence of the biomarkers for mutant ras-p21 and mutant p53 was found to be highly significantly associated with cumulative VC exposure (P for trend

Self-assembly behavior of a mixture system containing rod-coil block copolymers and rigid homopolymers was investigated by using Brownian dynamics simulations. The morphologies of formed hierarchical self-assemblies were found to be dependent on the Lennard-Jones (LJ) interaction εRR between rod blocks, lengths of rod and coil blocks in copolymer and mixture ratio of block copolymers to homopolymers. As the εRR value decreases, the self-assembled structures of mixtures are transformed from an abacus-like structure to a helical structure, to a plain fiber and finally are broken into unimers. The order parameter of rod blocks was calculated to confirm the structure transition. Through varying the length of rod and coil blocks, the regions of thermodynamic stability of abacus, helix, plain fiber and unimers were mapped. Moreover, it was discovered that two levels of rod block ordering exist in the helices. The block copolymers are helically wrapped on the homopolymer bundles to form helical string, while the rod blocks are twistingly packed inside the string. In addition, the simulation results are in good agreement with experimental observations. The present work reveals the mechanism behind the formation of helical (experimentally super-helical) structures and may provide useful information for design and preparation of the complex structures.

A TiAlN/MoS 2 -Ti coating was developed to improve the tribological characteristics of a single TiAlN coating. The MoS 2 -Ti layer was deposited by a DC magnetron sputtering system on the hard TiAlN coated SKD-II steel substrate. The titanium content in the MoS 2 -Ti layer was 11.3 at.% determined by EPMA. The surface morphology was observed by FE-SEM. The TiAlN layer exhibited excellent adhesion and hardness. However, the deposition of an MoS 2 -Ti layer on the TiAlN led to a significant improvement in tribological properties without affecting the adhesion to the substrate. The MoS 2 -Ti layer significantly decreased the friction coefficient of the TiAlN coating, and the drop was 48% after MoS 2 -Ti deposition. Also, the MoS 2 -Ti layer remarkably decreased the wear rate of the TiAlN coating.