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Primitive Endoderm (PrE) is an extraembryonic structure derived from inner cell mass (ICM) in the blastocysts. Its interaction with the epiblast is critical to sustain embryonic growth and embryonic pattern. In this study, we reported a simple and efficient method to induce the differentiation of mouse Embryonic Stem Cells (mESCs) into PrE cells. In the process of ESC monolayer adherent culture, 1 μM atRA and 10 μM CHIR inducers were used to activate RA and Wnt signaling pathways respectively. After 9 days of differentiation, the proportion of PrE cells was up to 85%. Further studies indicated that Wnt signaling pathway acted as a switch that RA induces mESCs differentiation between SMC and PrE cell. In the presence of only RA signaling, mESCs adopted the fate of smooth muscle cells (SMCs); Simultaneous activation of the Wnt signaling pathway changed the differentiation fate of mESCs into PrE cells. This efficient induction method can provide new cellular resources and models for relevant studies of PrE.

Sandwich-type CoSe2-CNWs@rGO/S cathodes were constructed to maximize sulfur utilization, limit sulfur agglomeration, and endure volume expansion during cycling.

Lithium-sulfur batteries (LSBs) are regarded as promising candidates for next-generation electrochemical energy storage systems due to their low cost and high energy density. However, the insulative sulfur, the volume expansion and high soluble polysulfides are three roots impeding their practical applications, and consequently bring challenges of low sulfur utilization, poor cyclic stability and sluggish redox kinetics. Herein, a special core-shell ZnS-CNTs/S@Ni(OH)2 (labeled as ZnS-CNTs/S@NH) cathode has been designed to overcome above obstacles and elevate the electrochemical performance. The ZnS-CNTs/S@NH cathode is synthesized via a facile step-by-step strategy, in which ZnS-decorated CNTs was used as a framework to load sulfur and followed with a ultrathin Ni(OH)2 (NH) layer encapsulation. The ZnS-CNT core combines merits of CNT network and polar ZnS quantum dots (QDs), accommodating the volume change, offering efficient pathways for fast electron/ion transport, and anchoring polysulfides through polar interactions. The outer Ni(OH)2 shell physically confines the active material and meanwhile provides plenty of catalytic sites for effective polysulfide chemisorption. Benefiting from these merits, the ZnS-CNTs/S@NH cathode exhibits excellent cell performances in comparison with ZnS-CNTs/S and CNTs/S. Its discharge capacity at different C-rates is optimal in the three cathodes, which decreases from 1037.0 mAh g-1 at 0.1 C to 646.1 mAh g-1 at 2.0 C. Its cyclic capacity also manifests the slowest reduction from 861.1 to 760.1 mAh g-1 after 150 cycles at 0.5 C, showing a high retention (88.3%) and a tiny average fading rate (0.078%). The strategy in this work provides a feasible approach to design and construct core-shell cathode materials for realizing practically usable Li-S batteries.

Although lithium-sulfur batteries (LSBs) are very promising in energy storage devices, their low conductivity, shuttle effect, and volume expansion unfavorably lead to sluggish kinetics and worsening electrochemical performance. To address these problems, we firstly prepared conductive carbon nanowires embedded with lithiophilic CoSe

Although Mn2+-doped aqueous ZnSe nanocrystals (NCs) have been reported, the obtained doped NCs usually possess multiple emission peaks originated from nanocrystal bandgap, defects, and Mn-dopants. ...

Electric field (E-field) effects on electric and optical properties of α-, β- and δ-SnSe have been investigated. Under the E-field, a tunable band gap of δ-SnSe appears, ranging from 2.23 to 1.26 e...

While conventional microelectronic integrated circuits based on electron charges approach the theoretical limitations in foreseeable future, next-generation nonvolatile logic units based on electro...

The low sulfur utilization, cycling instability, and sluggish kinetics are the critical obstructions to practical applications of lithium-sulfur batteries (LSBs). Constructing sulfur hosts with high conductivity, suppressed shuttle effect, and rapid kinetics is essential for their practical application in LSBs. Here, we synthetically utilized the merits of ZnSe quantum dots (QDs) and layered Ni(OH)

Constructing sulfur hosts with high electronic conductivity, large void space, strong chemisorption, and rapid redox kinetics is critically important for their practical applications in lithium–sulfur batteries (LSBs). Herein, by coupling ZnS quantum dots (QDs) with carbon nanotubes (CNTs), one multifunctional sulfur host CNT/ZnS-QDs is designed via a facile one-step hydrothermal method. SEM and TEM analyses reveal that small ZnS-QDs (−1 at 0.2 C to 544 mAh g−1 at 2.0 C, showing rate capability much higher than CNT/S and other CNT/ZnS-QDs/S samples. After 150 cycles, the cyclic capacity at 0.5 C exhibits a slow reduction from 1051 mAh g−1 to 771 mAh g−1, showing a high retention of 73.4% with a coulombic efficiency of over 99%. The electrochemical impedance spectroscopy analyses demonstrate that this special architecture juggles high conductivity and excellent confinement of polysulfides, which can significantly suppress the notorious shuttle effect and accelerate the redox kinetics. The strategy in this study provides a feasible approach to design efficient sulfur hosts for realizing practically usable LSBs.

Contra Instrumentalism: A Translation Polemic is the latest monograph of Venuti. It firstly examines the “untranslatability” and "loyalty" widely existing in translation theories, translation proverbs, and subtitle translation. Then the work criticizes the instrumentalism behind them, and proposes to think translation in a hermeneutic way. This review mainly introduces the general idea of each part, the structure and methodology of this book, and gives a brief comment on its value, shortcomings, enlightenment as well.

Genette (1987) describes a paratext as the threshold between a reader and a text, which presents the text to the readers, and influences how the text is received. Based on Genette’s definition, this study makes further exploration of paratext translation and proposes that paratexts in translated works are constituted of the paratext in the original text and the additional parts from the translator and other participants. Mainly based on the translation assessment model proposed by Katharina Reiss, this essay suggests a three-principle model for the paratext translation quality assessment in historical text. Then mainly taking footnotes in The Annals as a case study, the essay explores the fundamental factors that influence the paratext translation quality in the historical text, and suggests taking the principles of completeness, preciseness, and conciseness into consideration.

The low sulfur utilization, cycling instability, and sluggish kinetics are the critical obstructions to practical applications of lithium-sulfur batteries (LSBs). Constructing sulfur hosts with high conductivity, suppressed shuttle effect, and rapid kinetics is essential for their practical application in LSBs. Here, we synthetically utilized the merits of ZnSe quantum dots (QDs) and layered Ni(OH)2to boost the performance of LSBs. A novel core-shell ZnSe-CNTs/S@Ni(OH)2was constructed using the ZnSe-CNTs network as framework to load sulfur and following with Ni(OH)2encapsulation. The CNT network decorated with ZnSe QDs not only serves as a conductive framework providing fast electron/ion transfer channels, but also limits polysulfide diffusion physically and chemically. Layered Ni(OH)2, the wrinkled encapsulation, not only permits fast electron/ion transfer, but also buffers the expansion, confines active materials, and limits the polysulfide dissolution chemically. When used as a cathode, ZnSe-CNTs/S@Ni(OH)2presents enhanced electrochemistry performance compared with ZnSe-CNTs/S and CNTs/S. The average specific capacity decreases from 1021.9 mAh g-1at 0.2 C to 665.0 mAh g-1at 2 C, showing rate capacity much higher than ZnSe-CNTs/S and CNTs/S. After 150 cycles, the capacity at 0.5 C slowly reduces from 926.7 to 789.0 mAh g-1, showing high retention of 85.1%. Therefore, our investigation provides a new strategy to construct a promising sulfur cathode for LSBs.

Skyrmions have attracted significant interest due to their topological spin structures and fascinating physical features. The skyrmion phase arises in materials with Dzyaloshinskii-Moriya (DM) interaction at interfaces or in volume of non-centrosymmetric materials. However, although skyrmions were generated experimentally, one critical intrinsic relationship between fabrication, microstructures, magnetization and the existence of skyrmions remains to be established. Here, two series of CoFeB ultrathin films with controlled atomic scale structures are employed to reveal this relationship. By inverting the growth order, the amount of defects can be artificially tuned, and skyrmions are shown to be preferentially formed at defect sites. The stable region and the density of the skyrmions can be efficiently controlled in the return magnetization loops by utilizing first-order reversal curves to reach various metastable states. These findings establish the general and intrinsic relationship from sample preparation to skyrmion generation, offering an universal method to control skyrmion density., 25 pages, 5 figures

A series of blue-emitting Sr5Al2F16:Eu2+ phosphors were prepared by a simple solid-state reaction route. The phase structure was confirmed by the powder X-ray diffraction (XRD) and the Generalized Structure Analysis System (GSAS) refinement program. Under different monitored wavelengths, due to the multiple and distinguishable sites of Eu2+ ions, the phosphors exhibit different absorption bands. The corresponding mechanisms of luminescence property and concentration quenching behavior were proposed in detail. In addition, the optimum doping concentration of Eu2+ ions was eventually proved to be 2.0 mol%. Finally, the temperature-dependent emission properties of Eu2+ ions in Sr5Al2F16 lattice from 10 K to 510 K were conducted to evaluate the thermal stability. All above results indicate that Sr5Al2F16:Eu2+ phosphors can used as an appropriate candidate for the blue-InGaN chips based white light emitting diode (WLEDs) in future.

VO2(B), VO2(M), and V2O5 are the most famous compounds in the vanadium oxide family. Here, their gas-sensing properties were investigated and compared. VO2(B) nanoflakes were first self-assembled via a hydrothermal method, and then VO2(M) and V2O5 nanoflakes were obtained after a heat-phase transformation in nitrogen and air, respectively. Their microstructures were evaluated using X-ray diffraction and scanning and transmission electron microscopies, respectively. Gas sensing measurements indicated that VO2(M) nanoflakes were gas-insensitive, while both VO2(B) and V2O5 nanoflakes were highly selective to ammonia at room temperature. As ammonia sensors, both VO2(B) and V2O5 nanoflakes showed abnormal p-type sensing characteristics, although vanadium oxides are generally considered as n-type semiconductors. Moreover, V2O5 nanoflakes exhibited superior ammonia sensing performance compared to VO2(B) nanoflakes, with one order of magnitude higher sensitivity, a shorter response time of 14&ndash, 22 s, and a shorter recovery time of 14&ndash, 20 s. These characteristics showed the excellent potential of V2O5 nanostructures as ammonia sensors.

GaN-based light emitting diodes (LEDs) have been grown by metalorganic chemical vapor deposition on Si(111) substrate with and without 3C-SiC intermediate layer (IL). Structural property has been characterized by means of atomic force microscope, X-ray diffraction, and transmission electron microscope measurements. It has been revealed that a significant improvement in crystalline quality of GaN and superlattice epitaxial layers can be achieved by using 3C-SiC as IL. Regarding of electrical and optical characteristics, it is clearly observed that the LEDs with its IL have a smaller leakage current and higher light output power comparing with the LEDs without IL. The better performance of LEDs using 3C-SiC IL can be contributed to both of the improvements in epitaxial layers quality and light extraction efficiency. As a consequence, in terms of optical property, a double enhancement of the light output power and external quantum efficiency has been realized.

A low-pass Ka-band MEMS tunable filter based on the high-resistivity silicon substrate with Electromagnetic-Bandgap Structure (EBG) is presented. The tunable filter consists of multiple MEMS switches fabricated by a CMOS-compatible surface micromachining process. The equivalent circuit model of the tunable EBG bandstop filter was derived based on the circuit analysis theory. The dispersion characteristics obtained are useful for describing and understanding the propagation characteristics of the EBG and the MEMS bridges. The performance of the single MEMS bridges is discussed. The measurement results of the tunable MEMS filter showsa 3-dB cutoff frequency tunable from 34.25 GHz to 26.60 GHz, while the average insertion loss varies from 0.25 dB to 0.22 dB. The whole chip size is 3.6 mm × 1.6 mm. This work demonstrates a high-performance miniaturized tunable low-pass filters at mm-waves frequency bands using Electromagnetic-Bandgap Structure.

The magnetic skyrmionium can be seen as a coalition of two magnetic skyrmions with opposite topological charges and has potential applications in next-generation spintronic devices. Here, we report the current-driven dynamics of a skyrmionium in a ferromagnetic nanotrack with the voltage-controlled magnetic anisotropy. The pinning and depinning of a skyrmionium controlled by the voltage gate are investigated. The current-driven skyrmionium can be used to mimic the skyrmionium diode effect in the nanotrack with a voltage gate. We have further studied the skyrmionium dynamics in the nanotrack driven by a magnetic anisotropy gradient in the absence of spin current. The performance of a single wedge-shaped voltage gate at different temperatures is studied. Our results may provide useful guidelines for the design of voltage-controlled and skyrmionium-based spintronic devices.

Silicon nanowires (SiNWs) with a length of about 8 μm and zinc oxide nanorods (ZnONRs) with a length of about 200 nm were prepared by wet chemical etching and chemical bath deposition, respectively. Capacitive humidity sensors based on ZnONRs/SiNWs were fabricated and their humidity sensing properties were examined at room temperature (∼25 °C). The largest response range of the sensors is 2.40–64.40 nF when the relative humidity (RH) changes from 11.30 to 97.69%. The sensitivity is 0.69 nF/% RH. The longest response and recovery time is ∼26 and 7 s, respectively, which corresponding to 97.69% RH. The sensors are proven to have long-term stability, with a maximum relative standard deviation (RSD) of 2.93% corresponding to 11.30% RH during about one month at room temperature in air. ZnONRs/SiNWs are a better ideal capacitive humidity sensing material compared to those we previously reported. It might be easy to miniaturize and compatible with traditional integrated circuit (IC) process.

To improve field emission (FE) properties of V2O5, ZnO nanowires were used as templates and V2O5 nanoparticles were successfully grown and coated on them via a chemical vapor deposition (CVD) route followed by a rapid anneal treatment. The particle size and shape were determined by the temperature sensitive crystallization of V2O5. Three different samples having different surface morphologies were obtained at 370, 450 and 510 °C, respectively, in which V2O5 nanoparticles were grown on the surface forming sharp tips. SEM results revealed that the sample of 450 °C had the sharpest tips, and its chemical states and components were examined by XRD analysis, confirming the coating of V2O5 on ZnO. FE measurements for the three samples showed enhanced FE properties compared with pure V2O5 and bare ZnO. Moreover, FE properties for the sample of 450 °C are the best in the three samples, showing a low turn-on field reduced markedly from 4.38 V/μm (V2O5) to 2.25 V/μm and a high current density (at 5 V/μm) increased markedly from 0.21 mA/cm2 (V2O5) to 4.98 mA/cm2. The corresponding field enhancement factor (β) also increased greatly to 3066, much higher than the value of pure V2O5 nanoparticles ( β V 2 O 5 ≈ 920 ) and higher than the value of bare ZnO (βZnO ≈ 1590). The equipotential model analyses revealed that the enhanced FE properties were attributed to sharp tips formed by V2O5 nanoparticles, where the introduced V2O5 tips act as independent emitters on the surface and high local electric field around these tips increased the tunneling probability.

Controllable doping is an effective way of tuning the properties of semiconductor nanocrystals (NCs). In this work, a simple strategy of fast doping Cu ions into ZnSe NCs under ambient conditions was proposed. The principle of doping is based on hydrazine (N2H4) promoted cation exchange reaction. By direct addition of Cu ion stock solution into the preformed ZnSe NCs, Cu doped ZnSe NCs can be obtained. Furthermore, the emission of doped NCs can be tuned by changing the amount of impurity ion addition. The cation exchange reaction is facilitated by three factors: 1) N2H4 addition, 2) fast impurity ions, and 3) partial stabilizer removal. The proposed cation exchange reaction in aqueous solution could be an alternate route for NC doping as well as synthesis of ionic NCs.

Three flower-like and one rod-shape cubic Cu 2 S nanostructures were successfully synthesized from a facile hydrothermal method employing CuCl 2 ·2H 2 O and thiourea as Cu and S source with different volume ratio of ethanol and distilled water, respectively. Hexadecyl trimethyl ammonium Bromide (CTAB) plays an important role in forming the nanorod. After thermal annealing treatment, tetragonal Cu 1.81 S nanoflower and nanorod were obtained for the first time. Field emission (FE) properties of these nanostructures were investigated for the first time. The results indicated that the tetragonal Cu 1.81 S nanorods had excellent field emission performance with turn-on field of ∼2.2 V μm −1 , threshold field of ∼5.1 V μm −1 and enhancement factor of 1532. It showed that the tetragonal Cu 1.81 S nanostructures were competitive material in field emission applications.

There are a large number of paramagnetic defects on the surface of as-grown silicon nanowires (SiNWs) in contrast to H-terminated silicon (Si). Herein, SiNWs arrays were fabricated by chemical etching, Nickel nanoparticles (Ni NPs) were deposited on the surface of SiNWs arrays by the electroless plating. The influence of paramagnetic defects on the magnetic property of Ni/SiNWs was investigated and compared to Ni/Si. The paramagnetic defects of as-grown SiNWs and H-terminated Si were studied by ESR and FTIR spectra. The diameter distribution of Ni NPs on the surface of SiNWs arrays and Si was probed by SEM and fitted by the lognormal probability density function. The results reveal that the diameters of Ni NPs are 35.09 ± 0.53 and 34.92 ± 0.72 nm respectively. The magnetic properties of M–H hysteresis loops for Ni/SiNWs and Ni/Si were measured from 5 to 400 K. With the temperature increasing, the saturation magnetization of Ni/SiNWs and Ni/Si decreases gradually due to the thermal activation effect. Overall temperature range (5–400 K), the saturation magnetization of Ni/Si follows the modified Bloch's law. However, the data of Ni/SiNWs are only valid for high temperature range (50–400 K). At low temperature (5 K), there is an abrupt increase and the experimental data deviated from the modified Bloch model. This deviation at low temperature is associated with surface paramagnetic defects of SiNWs.

A ternary plasmonic photocatalyst consisting of Au-decorated V2O5@ZnO heteronanorods was successfully fabricated by an innovative four-step process: thermal evaporation of ZnO powders, CVD of intermediate on ZnO, solution deposition of Au NPs, and final thermal oxidization. SEM, TEM, EDX, XPS, and XRD analyses revealed that the interior cores and exterior shells of the as-prepared heteronanorods were single-crystal wurtzite-type ZnO and polycrystalline orthorhombic V2O5, respectively, with a large quantity of Au NPs inlaid in the V2O5 shell. The optical properties of the ternary photocatalyst were investigated in detail and compared with those of bare ZnO and V2O5@ZnO. UV-vis absorption spectra of ZnO, V2O5@ZnO, and Au-decorated V2O5@ZnO showed gradually enhanced absorption in the visible region. In addition, gradually decreased emission intensity was also observed in the photoluminescence (PL) spectra, revealing enhanced charge separation efficiency. Because of these excellent qualities, the photocatalytic behavior of the ternary photocatalyst was studied in the photodegradation of methylene blue under UV-vis irradiation, which showed an enhanced photodegradation rate nearly 7 times higher than that of bare ZnO and nearly 3 times higher than that of V2O5@ZnO, mainly owing to the enlarged light absorption region, the effective electron-hole separation at the V2O5-ZnO and V2O5-Au interfaces, and strong localization of plasmonic near-field effects.

A tunable bandstop filter applying the micromachined technology is designed, simulated and fabricated. The filter is realized by incorporating defected ground structures structures with the micromachined switches. The surface micromachining fabrication process is employed on the high resistivity silicon substrate to fabricate the filter. The measured 3-dB cut-off frequency changes of the reconfigurable low-pass filter for four different states has been analyzed. The measured insertion loss is very lower in four tuning range of the filter. This work demonstrates the possibility of high-performance compact-size reconfigurable filters at mm-waves using multiple-contact micromachined switches. Simulated and measured results of the proposed filter show good agreements. The entire reconfigurable filter was realized in a small chip size of 1.2 mm × 1.5 mm.

A novel hierarchical MoS2@SnO2 hetero-nanoflower was successfully synthesized by a facile, two-step hydrothermal method without using any additives or surfactants. One possible growth mechanism of the hetero-nanostructure was presented in detail based on OH− ion-dependent experimental facts. Due to the formation of the p–n junctions and the increased specific surface area in the composites, an outstanding photocatalytic activity of the as-prepared sample was obtained by monitoring the photodegradation of methylene blue (MB). According to the data, after irradiation for 100 min, the remaining MB in solution is about 26% for MoS2 nanoflowers and 9.5% for MoS2@SnO2 hetero-nanoflowers. Moreover, an excellent field-emission performance was obtained from MoS2@SnO2 hetero-nanoflower relative to the pure MoS2 with the turn-on field decreasing from 4.2 V μm−1 to 3.4 V μm−1 and the threshold field decreasing from 6.2 V μm−1 to 5.2 V μm−1, which is mainly attributed to the increased field-emission points and MoS2–SnO2 heterojunction.

The combinations of hollow MoS2 micro@nano-spheres were successfully fabricated through a one-step hydrothermal method. A possible growth mechanism was presented in detail based on time-dependent experimental facts. Besides, the photocatalytic activities of the samples were evaluated by monitoring the photodegradation of methylene blue (MB). The adsorption value of 150 mg g−1 shows a strong adsorption capability in the dark. After irradiation for only 30 min, the remaining MB in solution is about 9.7%. Moreover, the humidity sensing properties of the samples were measured for the first time. The results revealed high sensitivity at high RH, small humidity hysteresis, fast response and recovery times, and good stability. The greatest sensitivity is 32.19 nF/% RH and the maximum hysteresis is ∼6.3% RH. For humidity cycling of 17.2–89.5–17.2% RH, the response and recovery times are ∼140 s and ∼80 s, respectively. Capacitance fluctuations for one month are less than ±7% at various relative humidities (RHs).

Multi-layered VS2 nanosheets were synthesized via a facile hydrothermal process without using any additives or surfactants. Due to the large quantities of sharp edges, a VS2 nanosheet can serve as an efficient edge emitter for field emission (FE). The FE properties of VS2 nanosheets were investigated for the first time. The results indicated that the VS2 nanosheets had an excellent field emission performance with a turn-on field of ∼1.4 V μm−1 and a threshold field of ∼2.6 V μm−1 on a Si substrate. Moreover, the FE properties of ZnO-coated VS2 nanosheets were also investigated. The VS2/ZnO nanocomposite showed enhanced field emission properties with a turn-on field of ∼1.2 V μm−1 and a threshold field of ∼2.2 V μm−1, as well as an excellent emission stability without significant current degradation, which resulted from a well contacted metal–semiconductor junction and extra emission sites. In addition, the FE properties of the VS2 nanosheets were preserved on a highly flexible polyethylene terephthalate (PET) substrate. Approximately the same values of the turn-on field (∼1.8 V μm−1) and the threshold field (∼3.2 V μm−1) were measured on bent and unbent PET substrates.

Red-emitting Mn4+-doped A2CaWO6 (A = Ca, Sr, Ba) phosphors have been synthesized by solid-state reaction. The crystallinities and structural properties were examined by X-ray diffraction (XRD). The luminescence properties were studied by luminescence excitation, emission spectra and decay curves. All the synthesized materials emit red light peaking around 680 nm which can be assigned to the 2Eg → 4A2g spin-forbidden transition of Mn4+ ions under the excitation of ultraviolet to blue light. The critical quenching concentrations of Mn4+ in A2CaWO6 (A = Ca, Sr, Ba) system are evaluated. The temperature dependent emission spectra and decay curves (10–520 K) were introduced to evaluate the thermal stability. Surprisingly, the proposed three kinds of red phosphors show quite different thermal behavior, which can be ascribed to the different crystal structure environment of Mn4+ ions in A2CaWO6 (A = Ca, Sr, Ba) system.

The optical properties of the type-II lineup In x Al1−x N–Al0.59Ga0.41N/Al0.74Ga0.26N quantum well (QW) structures with different In contents are investigated by using the six-by-six K–P method. The type-II lineup structures exhibit the larger product of Fermi–Dirac distribution functions of electron f c n and hole ( 1 − f v U m ) and the approximately equal transverse electric (TE) polarization optical matrix elements ( | M x | 2 ) for the c1–v1 transition. As a result, the peak intensity in the TE polarization spontaneous emission spectrum is improved by 47.45%–53.84% as compared to that of the conventional AlGaN QW structure. In addition, the type-II QW structure with x ∼ 0.17 has the largest TE mode peak intensity in the investigated In-content range of 0.13–0.23. It can be attributed to the combined effect of | M x | 2 and f c n ( 1 − f v U m ) for the c1–v1, c1–v2, and c1–v3 transitions.

Three pure V 2 O 5 micro/nano-structures including rods, hierarchical wires and porous tubes are synthesized via a chemical vapor deposition process by adjusting the oxidation temperature. Their surface-to-volume ratio increases significantly because of particle size decrease, pore quantity increase and hollow structure formation. Lithium-ion storage investigation in aqueous electrolyte indicates that the enlargement of surface area can suppress irreversible phase transition and lead to significant improvement of cycling stability, storage capacity and electrochemical kinetics. Furthermore, scan-rate dependence cyclic voltammetry analysis demonstrates that both pseudocapacitive and bulk Li + storage are within these V 2 O 5 electrodes and the relative contributions of them depend strongly on the scan rate. In porous V 2 O 5 micro/nano-tubes, the surface pseudocapacitive storage dominates the total storage capacity at scan rates above 0.06 V s −1 , whereas the bulk Li + storage is the domination effect for V 2 O 5 micro/nano-rods at the scan rate ranging from 0.02 to 0.3 V s −1 . At the special scan rate, the maximum and minimum capacity is observed in V 2 O 5 porous micro/nano-tubes and micro/nano-rods, respectively. These studies should be useful for elucidating the morphological effects on Li-ion storage for V 2 O 5 -based electrodes. By varying key morphological parameters, the pseudocapacitive properties of V 2 O 5 micro/nano-structure electrodes are expected to be affected.

This paper presents a novel approach in order to construct low-loss reconfigurable impedance matching networks and tuners using MEMS series-contact switches and periodic defected-ground-structures (DGSs) implemented on coplanar waveguide (CPW) transmission lines. The application of DGSs results in an improved insertion loss and power handling capability compared to the conventional RF MEMS impedance tuning networks. The proposed structure consists of 12 DGSs and RF MEMS series-contact switches. The tunable matching network was fabricated on a silicon substrate and is only 1.4×̃˾̈˰̽̽˰̹̾˰̵̹̓͊˾˰̸̵̤˰̵̵̴̱̽̓͂ͅ˰̼̿̓̓˰̶̿˰̸̵̈́˰̵͇̻̾̈́̿͂˰̸̵͇̾˰̵̴̓ͅ˰̈́̿˰̸̱̳̽̈́˰̱˰́̀˰Ω˰̴̼̱̿˰̈́̿˰̅̀˰Ω˰̶͂̿m 5GHz up to 40 GHz is only 0.8 dB. The results show that the tuner can achieve a broadband impedance match for a wide variety of loads that are either purely resistive or that have a large reactance as well.

Cubic marigold-like Cu2S nanostructures were synthesized from a facile hydrothermal process without using any additives or surfactants. After thermal annealed at different condition, monoclinic Cu2S and tetragonal Cu1.81S nanostructures were obtained for the first time, maintaining the marigold-like morphology undestroyed. Field emission (FE) properties of these three types of nanostructures were investigated for the first time. The results indicated that the tetragonal Cu1.81S nanostructures had excellent field emission performance with turn-on field of and threshold field of . Moreover, their photocatalytic properties of the three nanostructures were also investigated by photodegradating methylene blue (MB). The results showed that the tetragonal Cu1.81S nanostructures may be a competitive material in both field emission and photocatalytic applications.

Interlayer exchange coupling (IEC) in a series model diluted magnetic semiconductor (DMS) multilayer consisting of two magnetic (Ga, Co)N layers separated by non-doped or Mg-doped GaN non-magnetic spacers has been studied by first-principles calculations. The effects of the spacer thickness and hole doping to the IEC were studied systematically. It is observed that (1) for the GaN spacers without Mg doping, the IEC between two magnetic (Ga, Co)N layers is always ferromagnetic, which is clarified as an intrinsic character of the Ruderman–Kittle–Kasuya–Yoshida (RKKY) interaction based on a two-band model for a gapped system; and (2) for the Mg-doped GaN spacers, the IEC is tunable from ferromagnetic to antiferromagnetic by varying the spacer’s thickness and the dopant’s site.

Several V 2 O 5 nanostructures including nanowires, nanowaxberries and nanoflowers were successfully synthesized via a hydrothermal process with NH 4 VO 3 as precursor and polymer polyvinyl pyrrolidone (PVP) as surfactant. In the synthesis process, morphologies of the products are found to be sensitive to the concentration of the surfactant. Electrochemical properties measurements of these three nanostructures are performed, showing that V 2 O 5 nanoflowers have the best stability and highest Li ion diffusion coefficient compared to other two kinds of structures, which is most suitable for application in Li-ion battery electrodes. Moreover, field emission (FE) measurements are also performed, showing that these nanostructures possess excellent field emission properties, in which V 2 O 5 nanowaxberries have the lowest turn-on field, threshold field and the highest field-enhancement factor of 2.9 V/μm, 5.7 V/μm and 2468, respectively, making them a promising material for field emitters.

The α-Fe2O3/Si two-dimensional (2D) photonic crystal (PC) with hexagonal honeycomb structure was fabricated by self-assembly and solution-dipping method based on colloidal monolayer template with 780 and 470 nm diameter polystyrene (PS) spheres. Optical diffraction measurement was carried out under wavelengths of 800, 532 and 400 nm. An interesting dispersion phenomenon with a hexagonal diffraction pattern composed of six elliptical spots is observed under specific wavelengths. Both theoretical and experimental calculations reveal that the diffraction can only occur when the incident wavelength is smaller than $\sqrt{3}/2$ of lattice constant, and both the shape and distribution of these spots can be modified by the PC lattice constant and the incident wavelength. All these results reveal that optical properties of these 2D PC slabs are different from conventional diffractive devices.

VO2 (B) nanostructures were synthesized via a facile hydrothermal process using V2O5 as source material and oxalic acid as reductant. Three nanostructures of nanorods, nanocarambolas and nanobundles were found existing in the products, and a continuous changing of morphology was found in the synthesis process, during which the proportion of these three types of nanostructures can be adjusted by altering the concentrations of oxalic acid. The microstructures were evaluated using X-ray diffraction and scanning and transmission electron microscopies, respectively. FE properties measurement of these three types of nanostructures showed that the nanobundles have the best field emission performance with a turn-on field of ∼1.4 V/μm and a threshold field of ∼5.38 V/μm. These characteristics make VO2 (B) nanostructures a competitive cathode material in field emission devices.

VO 2 (M 1 ) nanostructures were synthesized via hydrothermal and heat-transformation processes using NH 4 VO 3 as source and oxalic acid as reductant. Different morphologies of nanorods, nanoflakes, nanoflowers, and nanospheres were obtained by adjusting the concentration of oxalic acid. Their microstructures were evaluated using X-ray diffraction and scanning and transmission electron microscopies, respectively. FE properties measurement of these nanostructures showed that the hollow nanospheres have best field emission performance with turn-on field of ∼4 V/μm and threshold field of ∼11.4 V/μm. Due to the high surface-to-volume ratio, nanoflowers were chosen to test their humidity sensing properties, demonstrating that the sensor based on VO 2 (M 1 ) nanoflowers have fast response speed with response time of ∼13 s and recovery time of ∼5 s. This indicates that VO 2 (M 1 ) nanostructures are promising candidate materials for the application in high performance humidity sensors.

Resettlement is considered a major policy measure in two major Chinese policy programs, the “Great Development of the West” and poverty alleviation in the new century, and the “New Countryside Development”. The selection of the target location of resettlement sites for poverty-stricken villages is of critical importance to the success of resettlement projects, yet the selection process is challenged by the need for analyzing a variety of contributing factors, and the need for many rounds of tedious data processing. So in this paper we present an in-depth analysis of the major factors and data processing model concerning mountainous povertystricken villages, which also takes a major part of China’s poor villages. Our analysis shows the following factors bear the most importance in resettlement selection: 1) topography: candidate areas should have slope less than 25 degrees and altitude less than 2400 meters. 2) accessibility: close to market conventions places and transportation facilities. 3) farming resources: with abundant land and water resources. 4) non-intrusiveness: interests of receiving villages should be considered and negative impact minimized. A simple measure could be having the candidate area 1000 m away from the receiving residents. 5) Minimal ecological and political footprint: candidate areas shall not conflict with nature conservation areas or nationally planned key land use projects. 6) Social and cultural compatibility: residents will better off if relocated in the same county, considering language, religion, ethnic culture and other factors. Taking Makuadi, Lushui County of Nujiang Prefecture as a case study, we demonstrate how GIS analysis and modeling tools can be used in the selection process of resettlement projects in mountainous areas.

VO2(B) nanoflowers were synthesized via hydrothermal method, and VO2(M) nanoflowers were obtained through heat-transformation. Two sensors based on VO2(B) and VO2(M) nanoflowers were fabricated and their humidity characteristics were studied. It was found that these sensors exhibited fast response and recovery, perfect reproducibility and good stability. The VO2(M) type sensor is more sensitive at high RH and can be used for high humidity detection. On the contrary, the VO2(B) type sensor has a higher sensitivity at low RH, and can be used for low humidity detection, which is difficult for humidity sensors based on many other semiconductor oxides.