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AR, VR Headset for “metaverse” is one of candidates to widen human life experiences with virtual reality. Display requirement for headset is the high resolution as to 3000ppi that needs to enhance outcoupling efficiency of OLED (OLEDoS). We optimized 2D hole arrayed double anode structure for mass production with materials, thickness of anode and interlayer, process variation of etching top anode, and particles in double anodes. Outcoupling efficiency of optimized structure is improved to 1.377 folds than conventional TE‐OLEDs. We hope that this study promotes more approaches to excite SPPs of anode.

Quadruped animals in the nature realize high energy efficiency locomotion by automatically changing their gait at different speeds. Inspired by this character, an efficient adaptive diagonal gait locomotion controller is designed for quadruped robot. A unique gait planning method is proposed in this paper. As the speed of robot varies, the gait cycle time and the proportion of stance and swing phase of each leg are adjusted to form a variety of gaits. The optimal joint torque is calculated by the controller combined with Virtual Model Control (VMC) and Whole-Body Control (WBC) to realize the desired motion. The gait and step frequency of the robot can automatically adapt to the change of speed. Several experiments are done with a quadruped robot made by our laboratory to verify that the gait can change automatically from slow-trotting to flying-trot during the period when speed is from 0 to 4 m/s. The ratio of swing phase is from less than 0.5 to more than 0.5 to realize the running motion with four feet off the ground. Experiments have shown that the controller can indeed consume less energy when robot runs at a wide range of speeds comparing to the basic controller.

Objective: This study aimed to examine the role of long non-coding RNA PCED1B antisense RNA 1 (PCED1B-AS1) in the development of hepatocellular carcinoma (HCC). Methods: A total of 62 pairs of HCC tissues and adjacent non-tumor tissues were obtained from 62 HCC patients. The interactions of PCED1B-AS1 and microRNA-34a (miR-34a) were detected by dual luciferase activity assay and RNA pull-down assay. The RNA expression levels of PCED1B-AS1, miR-34a and CD44 were detected by RT-qPCR, and the protein expression level of CD44 was determined by Western blotting. The cell proliferation was detected by cell proliferation assay, and the cell invasion and migration by transwell invasion assay. The HCC tumor growth after PCED1B-AS1 was downregulated was determined by in vivoanimal study. Results: PCED1B-AS1 was highly expressed in HCC tissues, which was associated with poor survival of HCC patients. Furthermore, PCED1B-AS1 interacted with miR-34a in HCC cells, but they did not regulate the expression of each other. Additionally, PCED1B-AS1 increased the expression level of CD44, which was targeted by miR-34a. The cell proliferation and invasion assay revealed that miR-34a inhibited the proliferation and invasion of HCC in vitro, while CD44 exhibited the opposite effects. Furthermore, PCED1B-AS1 suppressed the role of miR-34a. Moreover, the knockdown of PCED1B-AS1 repressed the HCC tumor growth in nude mice in vivo. Conclusion: PCED1B-AS1 may play an oncogenic role by regulating the miR-34a/CD44 axis in HCC.

The Moderate Resolution Imaging Spectroradiometer (MODIS) leaf area index (LAI) product is critical for global terrestrial carbon monitoring and ecosystem modeling. However, MODIS LAI is calculated on a pixel-by-pixel and day-by-day basis without using spatial or temporal correlation information, which leads to its high sensitivity of LAI to uncertainties in observed reflectance, resulting in an increased noise level in time series. While exploiting prior knowledge is a common practice to fill gaps in observations, little research has been conducted on reducing noisy fluctuations and improving the overall quality of the MODIS LAI product. To address this issue, we proposed a spatiotemporal information composition algorithm (STICA), which directly introduces prior spatiotemporal correlation and multiple quality assessment (MQA) information into the existing MODIS LAI product. STICA reduces the noise level and improves the quality of the product while maintaining the original physically based (radiative transfer model, RTM) LAI production process. In our analysis, the $R^{2}$ increased from 0.79 to 0.81 and the root-mean-square error (RMSE) decreased from 0.81 to 0.68 compared to the ground-based LAI reference. The improvement was more pronounced with the degradation of the data quality. STICA reduced noisy fluctuations in the LAI time series to varying degrees among eight biome types. In the Amazon forest, STICA significantly improved the time-series stability of LAI. Moreover, STICA can effectively eliminate abnormal declines in time series and correct for extreme outliers in LAI. We expect that the MODIS LAI reanalyzed product generated by this method will better support the application of high-quality LAI datasets.

Birefringent materials with large optical anisotropy, which can be used to modulate the polarization of light, play a key role in laser techniques and science. However, the exploration studies of new, superior birefringent materials develop extremely slowly due to the lack of effective guidelines for rational design. Herein, three antimony(III) fluoride oxalates, namely, Na2Sb2(C2O4)F6, K2Sb2(C2O4)F6, and Cs2Sb2-(C2O4)2F4·H2O, were successfully synthesized through a rational combination of π-conjugated C2O42−anions and Sb3+cations with stereochemically active lone pairs. These oxalates feature unique quasi-one-dimensional chain structures that induce large optical anisotropy. Remarkably, Cs2Sb2(C2O4)2-F4·H2O exhibits the largest birefringence (0.325@546 nm) among all reported antimony(III)-based oxysalts. Detailed structural analysis and theoretical calculations confirmed that the optical anisotropy of these oxalates could be tuned through the synergetic interactions of templated cations and anionic functional groups. This work may open the door to efficiently designing excellent birefringent materials and guide the further discovery of other novel structure-driven functional materials.

The Yin–Yang complementarity strategy was first proposed to successfully develop a superior metal-free birefringent material C(NH2)3(HC4O4), which was fabricated by two kinds of planar π-conjugated units containing triangle [C(NH2)3]+cations and square [HC4O4]−anions. C(NH2)3(HC4O4) features a giant birefringence (0.313@546 nm), which is significantly enhanced compared to the commercially available birefringent materials.

Global optimization of multicomponent cluster structures is considerably time-consuming due to the existence of a vast number of isomers. In this work, we proposed an improved self-adaptive differential evolution with the neighborhood search (SaNSDE) algorithm and applied it to the global optimization of bimetallic cluster structures. The cross operation was optimized, and an improved basin hopping module was introduced to enhance the searching efficiency of SaNSDE optimization. Taking (PtNi)N(N= 38 or 55) bimetallic clusters as examples, their structures were predicted by using this algorithm. The traditional SaNSDE algorithm was carried out for comparison with the improved SaNSDE algorithm. For all the optimized clusters, the excess energy and the second difference of the energy were calculated to examine their relative stabilities. Meanwhile, the bond order parameters were adopted to quantitatively characterize the cluster structures. The results reveal that the improved SaNSDE algorithm possessed significantly higher searching capability and faster convergence speed than the traditional SaNSDE algorithm. Furthermore, the lowest-energy configurations of (PtNi)38clusters could be classified as the truncated octahedral and disordered structures. In contrast, all the optimal (PtNi)55clusters were approximately icosahedral. Our work fully demonstrates the high efficiency of the improved algorithm and advances the development of global optimization algorithms and the structural prediction of multicomponent clusters.

Vegetation phenology interacts strongly with climate through the exchange of carbon, water, momentum, and energy between terrestrial ecosystem and atmosphere. These vegetation dynamics in Northern Hemisphere permafrost regions have substantial uncertainties in previous studies, partly due to differences in datasets. Thus, reliable land surface phenology (LSP) retrievals are crucial for understanding the effects of climate change on ecosystems and biosphere‐atmosphere‐hydrosphere interactions. We assessed various LSP datasets at different spatial resolutions for 2001–2014, generated by different methods based on different satellite observations. We also assessed the accuracy of LSP by comparing with CO2flux phenology. For start of growing season (SOS), the comprehensive evaluation indicated MODIS phenology showed better consistency and higher accuracy with flux‐derived phenology observations (R= 0.54, RMSE = 36.2 days, bias<5 days). For end of growing season (EOS), we cannot conclusively determine which LSP performs best. In the Northern Hemisphere permafrost regions, SOS occurred at 100–150 days (April–May), and EOS occurred at 260–320 days (September–November). During 2001–2014, SOS occurred earlier by 0.33 ± 0.30 days/yr. Significant trends were observed for 6.4%–27.6% of pixels, averaging −1.30 ± 1.16 days/yr. EOS occurred earlier by 0.25 ± 0.43 days/yr, with significant trends averaging −0.52 ± 0.94 days/yr. Among LSPs, variability in EOS trends was significant, with even the direction of trends differing. This study may provide insights into LSP data selection and further understanding of vegetation dynamics and its mechanisms in permafrost regions. To better understand permafrost ecosystem dynamics associated with global change, the changes in vegetation and their spatial patterns in the Northern Hemisphere permafrost regions must be carefully evaluated. Thus, reliable land surface phenology (LSP) retrievals are very important. We therefore collected a total of 13 LSPs to understand how these products perform relative to each other and to ground observations and to quantify their uncertainties. MODIS and different GIMMS products are slightly more consistent overall. Considering different metrics, regions, and parameters, the temporal trends and spatial patterns of phenology indicate an earlier start to the growing season, but the end of the growing season is inconsistent. Bigger vegetation changes are found in the continuous permafrost region. These findings allow us to clarify the applicability of the LSP products, to provide a reference for data selection, and insights into the understanding of vegetation dynamics and their mechanisms in permafrost regions. The average start and end of the growing season occurs on 131 ± 18 days and 291 ± 4 days in Northern Hemisphere permafrost regionsComparison of 13 land surface phenology products to CO2flux phenology indicates that the RMSEs ranges from 27.25ays to 77.84 daysBoth the start and end of the growing season are earlier by 1.30 ± 1.16 and 0.52 ± 0.94 days/yr in Northern Hemisphere permafrost regions The average start and end of the growing season occurs on 131 ± 18 days and 291 ± 4 days in Northern Hemisphere permafrost regions Comparison of 13 land surface phenology products to CO2flux phenology indicates that the RMSEs ranges from 27.25ays to 77.84 days Both the start and end of the growing season are earlier by 1.30 ± 1.16 and 0.52 ± 0.94 days/yr in Northern Hemisphere permafrost regions

Although travelers tend to consider multi-dimensional hotel information when choosing their accommodation, few online travel agency (OTA) websites allow them to express their preferences and expectations for the selection criteria to obtain customized hotel ranking results. The lack of this function makes travelers have to spend extra time and effort in comparing different hotels to make the final decision. To solve this problem, a hotel ranking method considering travelers’ preferences and expectations is proposed based on multi-dimensional hotel information. In the method, considering the travelers’ actual process of hotel reservation through the OTA website, four types of hotel information (i.e., price, rating, location and text comment) are used. To make full use of these information, text mining, prospect theory and multi-attribute decision-making method are integrated into the proposed method. A case study is given to verify the reliability of the proposed method. The proposed method can be embedded into OTA websites to provide decision support for travelers’ hotel reservation, which will reduce the time spent by travelers in hotel search and comparison, thus effectively promote hotel reservation and improve traveler satisfaction.

Atomically precise metal nanoclusters (NCs) have garnered enduring interest in account of peculiar atomic stacking mode, discrete energy band structure, and abundant active sites, which are distinct from conventional metal nanocrystals. Nonetheless, research works on metal NCs-based photosystems are still in the infant stage in terms of generic light-induced instability, deficiency of metal NCs with photosensitization effect to trigger photoredox catalysis, and a complicated interfacial charge transport process. Herein, we concisely overview the latest concerted endeavors in constructing metal NCs-based photosystems for heterogeneous photocatalysis and photoelectrochemical water splitting with particular emphasis focusing on elucidating the charge transfer characteristics of metal NCs. Moreover, objective discussion and personal opinions on quintessential works are specifically provided. Future perspectives and challenges of metal NCs-based photosystems are eventually highlighted. We hope this perspective article would inspire ongoing interest in unleashing the emerging potentials of atomically precise metal NCs for solar energy conversion.

Cultural festivals symbolize cultural identities and serve as a carrier of national emotions. Evaluating the sustainability of cultural festivals tourism has long presented challenges for festival organizers and attendees. Based on the ecological niche theory, this paper presents a theoretical framework including the environment, resources, demands, and spatiotemporal niches to establish an evaluation system to analyze the sustainability of cultural festival tourism. Using an analytic hierarchy process, the sustainability of the Lantern Festival in 34 regions of China was empirically assessed. Results indicate that the environmental niche has the greatest impact on the sustainability of cultural festival tourism, and local government support plays a key role in sustainable festival development. Theoretical and practical implications are discussed based on the results.

The series of alkali-metal tin chloride sulfates A3Sn2(SO4)3–xCl1+2x(A = K, Rb, Cs; x= 0, 1), K3Sn2(SO4)3Cl, Rb3Sn2(SO4)2Cl3, and Cs3Sn2(SO4)2Cl3, were successfully synthesized through an improved mild hydrothermal method. Interestingly, in addition to the cation size effect, the structure-directing effect of anions induces different symmetries in the three title compounds, with K3Sn2(SO4)3Cl being noncentrosymmetric, while Rb3Sn2(SO4)2Cl3and Cs3Sn2(SO4)2Cl3are centrosymmetric. Powder second-harmonic generation (SHG) measurements indicate that K3Sn2(SO4)3Cl is a nonlinear optical material that is type I phase matchable with a weak SHG response (0.1× KDP). Photoluminescence tests reveal that the three title compounds emit strong greenish yellow, orange, and salmon light, respectively, under UV excitation, indicating that they are promising inorganic solid fluorescent materials. Simultaneously, a detailed structural analysis of all the known tin(II) halide sulfates has been performed, which will guide the systematic exploration of high-performance tin(II)-based functional materials in the future.

The fermentation of biomass allows for the generation of major renewable ethanol biofuel that has high energy density favorable for direct alcohol fuel cells in alkaline media. However, selective conversion of ethanol to either CO2or acetate remains a great challenge. Especially, the ethanol-to-acetate route usually demonstrates decentoxidation current density relative to the ethanol-to-CO2route that contains strongly adsorbed poisons. This makes the total oxidation of ethanol to CO2unnecessary. Here, we present a highly active ethanol oxidation electrocatalyst that was prepared by in situ decorating highly dispersed Mo sites on Pd nanosheets (MoOx/Pd) via a surfactant-free and facile route. We found that ∼2 atom % of Mo on Pd nanosheets increases the current density to 3.8 A mgPd–1, around 2 times more active relative to the undecorated Pd nanosheets, achieving nearly 100% faradic efficiency for the ethanol-to-acetate conversion in an alkaline electrolyte without the generation of detectable CO2, evidenced by in situ electrochemical infrared spectroscopy, nuclear magnetic resonance, and ion chromatography. The selective and CO2-free conversion offers a promising strategy through alcohol fuel cells for contributing comparable current density to power electrical equipment while for selective oxidation of biofuels to useful acetate intermediate for the chemical industry.

We selectively improved the viewing angle characteristics and light extraction efficiency of blue thermally activated delayed fluorescence (TADF) organic light-emitting diodes (OLEDs) by tailoring a nanofiber-shaped Si3N4layer, which was used as an internal scattering layer. The diameter of the polymer nanofibers changed according to the mass ratio of polyacrylonitrile (PAN) and poly(methyl methacrylate) (PMMA) in the polymer solution for electrospinning. The Si3N4nanofiber (SNF) structure was fabricated by etching an Si3N4film using the PAN/PMMA nanofiber as a mask, making it easier to adjust parameters, such as the diameter, open ratio, and height, even though the SNF structure was randomly shaped. The SNF structures exhibited lower transmittance and higher haze with increasing diameter, showing little correlation with their height. However, all the structures demonstrated a total transmittance of over 80%. Finally, by applying the SNF structures to the blue TADF OLEDs, the external quantum efficiency was increased by 15.6%. In addition, the current and power efficiencies were enhanced by 23.0% and 25.6%, respectively. The internal light-extracting SNF structure also exhibited a synergistic effect with the external light-extracting structure. Furthermore, when the viewing angle changed from 0° to 60°, the peak wavelength and CIE coordinate shift decreased from 20 to 6 nm and from 0.0561 to 0.0243, respectively. These trends were explained by the application of Snell’s law to the light path and were ultimately validated through finite-difference time-domain simulations.

Oxaliplatin (OXA) is a third-generation, platinum-based anticancer agent that is reported to induce cell toxicity in normal cells, which severely limits its applications. Its instability in aqua solution plays an important role in the cytotoxic effects. In this study, two novel drug–drug cocrystals of OXA were synthesized using baicalein (BAI) and naringenin (NAR) as cocrystal formers, as well as characterized by single crystal X-ray diffraction, powder X-ray diffraction, Fourier transform-infrared spectroscopy, and thermal analysis. Further evaluation of the dissolution profiles of the two cocrystals presented that they both have a reduced release rate and delayed hydrolysis compared to OXA. Theoretical analyses of the correlation between the structure and dissolution indicate that heterosynthons O–H···O and N–H···O hydrogen bonds are essential for reducing the dissolution rate of the two cocrystals. In addition, cell toxicity was studied using the CCK-8 assay, with the result that OXANAR may possess higher safety and OXABAI may have more significant effects on inhibiting cancer cells when compared to OXA.

In this work, BaYF5:20%Yb3+/2%Er3+/x%Bi3+(abbreviated as BaYF5:Yb,Er,Bix, where x= 0–3.0) upconversion nanoparticles (UCNPs) with various doping concentrations of Bi3+were synthesized through a simple hydrothermal method. The influence of the doping amount of Bi3+on the microstructures and upconversion luminescence (UCL) properties of the BaYF5:Yb,Er,BixUCNPs was studied in detail. The doping concentration of Bi3+has little influence on the microstructures of the UCNPs but significantly impacts their UCL intensities. Under excitation of a 980 nm near-IR laser, the observed UCL intensities for the BaYF5:Yb,Er,BixUCNPs display first an increasing trend and then a decreasing trend with an increase in the ratio x, giving a maximum at x= 2.5. A possible energy-transfer process and simplified energy levels of the BaYF5:Yb,Er,BixUCNPs were proposed. The potential of the BaYF5:Yb,Er,BixUCNPs as contrast agents for computerized tomography (CT) imaging was successfully demonstrated. An obvious accumulation of BaYF5:Yb,Er,Bixin tumor sites was achieved because of high passive targeting by the enhanced permeability and retention effect and relatively low uptake by a reticuloendothelial system such as liver and spleen. This work paves a new route for the design of luminescence-enhanced UNCPs as promising bioimaging agents for cancer theranostics.

In general, searching the lowest-energy structures is considerably more time-consuming for bimetallic clusters than for monometallic ones because of the presence of an increasing number of homotops and geometrical isomers. In this article, a basin hopping genetic algorithm (BHGA), in which the genetic algorithm is implanted into the basin hopping (BH) method, is proposed to search the lowest-energy structures of 13-, 38-, and 55-atom PtCo bimetallic clusters. The results reveal that the proposed BHGA, as compared with the standard BH method, can markedly improve the convergent speed for global optimization and the possibility for finding the global minima on the potential energy surface. Meanwhile, referencing the monometallic structures in initializations may further raise the searching efficiency. For all the optimized clusters, both the excess energy and the second difference of the energy are calculated to examine their relative stabilities at different atomic ratios. The bond order parameter, the similarity function, and the shape factor are also adopted to quantitatively characterize the cluster structures. The results indicate that the 13- and the 55-atom systems tend to be icosahedral despite different degrees of lattice distortions. In contrast, for the 38-atom system, Pt10Co28, Pt11Co27, Pt17Co21, Pt19Co19, Pt20Co18, and Pt30Co8tend to be disordered, while Pt21Co17presents a defected face-centered cubic (fcc) structure, and the remaining clusters are perfect fcc. The methodology and results of this work have referential significance to the exploration of other alloy clusters.

Nitrogen (N) losses from agricultural production contribute to detrimental impacts on water, soil, air, and human health. However, it is still lacking in evaluating global N budgets in agricultural systems. Hence, we conducted a global analysis on the current status of the N flows in the agricultural systems, explored the possible mitigation measures and challenges, and investigated the existing regulations on controlling N pollution. Globally, agricultural soils received a total of 73 kg of N ha–1year–1on average, including N fertilizer plus manure (61%), atmospheric N deposition (10%), and N litters and fixation (29%). The estimated global NH3loss to total N inputs was 17%, which led to a loss of $15 billion year–1. The N use efficiency (NUE) in Eastern China (33%) was much lower than that in the Eastern United States (65%) or Western Europe (61%), leaving much room to enhance the NUE to increase agricultural food production. Meanwhile, higher NH3losses from N fertilizers and manure were found in Eastern China (22%) than the Eastern United States (17%) and Western Europe (17%). We highlight the urgency to improve the NUE and decrease NH3loss with lower environmental consequences. Our results showed high potentials to mitigate NH3volatilization and enhance the NUE by various measures, such as substituting manure N for chemical fertilizer N, applying controlled release fertilizers, and urease inhibitors. These measures should be implemented in combination with the transfer of knowledge to farmers with new technologies and increasing the farm size to enhance the efficiency of agricultural production in the future.

CoMoO4has gained great attention as an anode material for lithium-ion batteries owing to its high theoretical capacity of 980 mAh g–1and relatively high electrochemical activity. Unfortunately, CoMoO4anode also has some drawbacks such as low electronic/ionic conductivity, inferior cyclic stability, and relative severe volumetric expansion during the lithiation/delithiation process, greatly inhibiting its further development and application. Herein, we report Co0.8Zn0.2MoO4/C nanosheet composite constructed via a novel and facile one-stone-three-birds strategy. The preparation of the Co0.8Zn0.2MoO4/C nanosheet is based on the following two-step process: the formation of Co/Zn nanosheet precursors derived from Co/Zn-ZIF rhombic dodecahedra via solvothermal pretreatment, followed by a calcination treatment with molybdic acid (H2MoO4) in air. The as-prepared Co0.8Zn0.2MoO4/C is monoclinic crystal structured composite with the in situ formed active carbon, which is well-defined nanosheet with a rough surface and mean thickness of 60–70 nm for a single sheet. This Co0.8Zn0.2MoO4/C nanosheet composite possesses a larger surface area of 37.60 m2g–1, showing a mesoporous structure. When used as anode materials, the as-obtained Co0.8Zn0.2MoO4/C composite can deliver as high as a discharge capacity of 1337 mAh g–1after 300 cycles at 0.2C and still retain the capacity of 827 mAh g–1even after 600 cycles at 1C, exhibiting outstanding lithium storage performances. The higher capacity and superior cyclic stability of the Co0.8Zn0.2MoO4/C composite should be ascribed to the synergistic effect of the substitution of Zn2+, in situ composited active carbon and the as-constructed unique microstructure for the Co0.8Zn0.2MoO4/C composite. Our present work provides a facile one-stone-three-birds strategy to effectively construct the architectures and significantly enhance electrochemical performances for other transition metal electrode materials.

Creeping breakdown caused by metal particles on the silicone rubber/XLPE interface of prefabricated cable joints often happens. Study on the development process of such insulation defect-led partial discharge (PD) can serve as a basis for the assessment of its severity level. In this paper, metal particles are sandwiched on the rubber/XLPE interface of a 35 kV prefabricated cable joint to simulate a creeping defect.

By introduction of K+, Rb+, and Cs+cations into the classical commercial nonlinear optical crystal LiB3O5(LBO), the series of novel mixed-alkali-metal borates Li2.6K0.4[B5O8(OH)2] (K-LBO), Li2.85Rb0.15[B5O8(OH)2] (Rb-LBO), and Li2.9Cs0.1[B5O8(OH)2] (Cs-LBO) have been obtained under hydrothermal conditions. The steric hindrance effect generated by the introduction of large alkali-metal cations and partial substitution of small Li+cations broke the three-dimensional (3-D) framework of [B3O7]5–borate–oxygen clusters in LBO and resulted in a structure rearrangement to produce infrequent [B10O26]22–2-D layers. The unique layered structure induced an increase in birefringence in A-LBOs (A = K, Rb, Cs), which is favorable for phase matching during second-harmonic generation. All three compounds are potential deep-ultraviolet nonlinear optical materials, which was proved by UV–vis–NIR diffuse reflectance spectroscopy and second-harmonic-generation measurements.

Two crystalline zinc phosphates, formulated as Zn(HPO4)(dl-C5H9NO2) (SCU-3) and Zn(HPO4)(C2H5NO2) (SCU-10), were prepared under surfactant-thermal conditions using amino acids as structure-directing agents. Different from traditional zeolites with 4-connected nets, the two compounds have different 3-connected nets related to zeolite ABW. Powder second-harmonic-generation (SHG) measurement shows that SCU-10 is a nonlinear optically active solid with an SHG efficiency about 1.4 times that of KH2PO4.

LiFe(MoO4)2microcrystals have been fabricated via a facile sol–gel driving process. The obtained LiFe(MoO4)2microcrystals are characterized through X-ray diffraction, thermal analysis, scanning electron microscope, transmission electron microscope and high resolution transmission electron microscope. The results demonstrate that the as-synthesized microcrystals possess triclinic structure and exhibit uniform particle size of 1–2 μm. When served as anode material for lithium ion batteries, LiFe(MoO4)2microcrystals display a very high specific capacity of 925 mAh g−1at a current rate of 1 C after 500 cycles and a high retention rate of 88%, showing superior electrochemical performance.

Na(1-x)Lix(Gd0.39Y0.39Yb0.2Er0.02)F4(0 ≤ x≤ 1) (denoted as Na(1-x)LixReF4) solid solution microcrystals with different microstructures have been synthesized by a facile hydrothermal method. The influences of Li+ion concentration on the morphology, crystal structure, grain size, and upconversion emission of the microcrystals are deeply investigated. It is found that the substitution concentration of Li+not only causes the phase transition but also induces variation in morphology and size. When the substitution concentration of Li+ions is lower (x≤ 0.3), the obtained Na(1-x)LixReF4microcrystals possess hexagonal structure and exhibit hexagonal prism in morphology. Whereas at the higher substitution concentration of Li+ions (x≥ 0.6), the crystalline phase of the final Na(1-x)LixReF4microcrystals transformed into tetragonal structure and their morphology changed into octahedron except for the sample Na(1-x)LixReF4with x= 0.9. Predictably, the obtained Na(1-x)LixReF4microcrystals at the moderate substitution concentration of Li+ions (x= 0.4 and 0.5) own the coexistent phases of hexagonal and tetragonal and display the obvious symbiotic morphologies of hexagonal prism and octahedron. All the samples showed characteristic emission peaks in green and red region with center wavelengths at 522 nm, 542 nm, and 652 nm respectively, and their upconversion intensities initially lift and then drop with the increasing x, giving the maximum at x= 0.5. Specifically, for the codoped Na0.5Li0.5ReF4microcrystal, its UC intensity of the strongest green emission at 542 nm is about 18 times and 73 times greater than that of the codoped NaReF4and LiReF4microcrystals, respectively. Moreover, the variation amplitude of intensity for the green emission bands is much greater than that of the red emission with the increasing x. It could obtain a superior host matrix for upconversion luminescence by means of the formation of Na(1-x)LixReF4solid solution at the feasible substitution concentration of Li+(0.2 < x≤ 0.6).

Two new antimony sulfate chlorides named (NH4)2SbCl(SO4)2and (NH4)SbCl2(SO4) were successfully synthesized through solvent-free synthesis method. (NH4)2SbCl(SO4)2exhibits a three-dimensional framework constructed of [SbCl(SO4)2]2–chains and NH4+ions. And the NH4+cations play the role of charge balance and provide the hydrogen bond constructed with oxygen atoms. (NH4)SbCl2(SO4) shows a two-dimensional layer structure that is composed of the regularly stacked [SbCl2(SO4)]−chains via hydrogen-bonding interactions. Both of the titled compounds possess the same chemical composition and the similar Sb–Cl–SO4chains, while hydrogen-bonding interactions and lone-pair cations play the synergistic effect on the framework structures and macroscopic centricities resulting in that the (NH4)2SbCl(SO4)2is centrosymmetric and the (NH4)SbCl2(SO4) is non-centrosymmetric (NCS). Powder second harmonic generation (SHG) measurements indicated that the NCS compound (NH4)SbCl2(SO4) is type I phase-matchable and exhibits SHG responses of ∼1.7 times that of KH2PO4.