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Doped BaZrO3 has outstanding stability and proton conductivity, and doped-ceria La2Ce2O7(LCO) has mixed conductivities of free-electron, oxygen-ion and proton, which are both potential electrolyte materials. Herein, one-step-co-fired BaZr0.8Y0.2O3-δ(BZY)-LCO composite electrolytes are prepared and characterized to give play to their respective advantages and avoid their shortcomings for low-temperature solid oxide fuel cells (LT-SOFCs). As for different components of BZY-LCO, the sintering activity increases with the increase of LCO content, however, the corresponding open circuit voltage decreases. Interestingly, the 30 %mol BZY-70 %mol LCO (3BZY-LCO) shows the best overall performance as functions of sintering activity, total conductivity, cell performance. As for the anode supported single cells, the maximum power density of 3BZY-LCO electrolyte can reach 0.581 W cm−2 at 750 °C using humidified hydrogen (3% H2O) as fuel. Preliminary experiment results suggest that the strategy of composite electrolyte can make up for the shortcomings of doped BaZrO3 and doped-ceria to a certain extent for LT-SOFCs.

The chaperone-assisted soluble expression and characterization of high molecular weight chitinase chiZJ408 in Escherichia coli BL21 were investigated. Chitin degradation products by chitinase chiZJ408 were analyzed. The results indicated that the introduction of the chaperone GroELS promoted the correct folding of chitinase chiZJ408 and increased its soluble expression by 14.9% (p < 0.05) in E. coli BL21. The optimal pH and temperature of chitinase chiZJ408 were respectively 6.0 and 50 °C. Chitinase chiZJ408 was stable at pHs of 4.0 ∼ 7.0 and at below 40 °C. Mg2+and Ca2+ had a significant impact on improving the activity of chitinase chiZJ408. Chitinase chiZJ408 was demonstrated to be exochitinase that cleaved the β-1,4-glycosidic bond of the chitin chain to generate only N,N'-diacetylchitobiose. This study broadens our understanding of chitinase and provides a basis for solving the problem of inclusion body formed by long fragment gene expression in E. coli.

Polyoxometalate-based organic-inorganic hybrid compounds (POIHCs) have been greatly developed due to their wide application prospects, but the pursuit of their directed synthesis via molecular design still remains a challenge. Herein, we demonstrate that the coordination modes of the Keggin-type [ZnW12O40]6- anion can be tuned, which leads to different semiconductor characteristics. Using the same building block, ligand, and metal ion (ZnW12, phen, Cu2+), we synthesized three new POIHCs with different bonding patterns by means of different coordination modes of ZnW12. The three POIHCs (H2phen){ZnW12O40[Cu(phen)2]2}·3H2O (1), {ZnW12O40[Cu(phen)(H2O)2]2[Cu(phen)(H2O)]}n·3H2O (2), and (Me4N)2{ZnW12O40[Cu(phen)(H2O)]2}n·5H2O (3) (phen = 1,10-phenanthroline) have been structurally characterized by single-crystal X-ray diffraction. Compound 1 appears as a zero-dimensional coordination complex cluster, while compounds 2 and 3 are both 1D chain structures with different Cu2+ bridge linkages. Although these three POIHCs possess the same chemical components, their semiconductor properties are different, which is demonstrated by measurements of transient photocurrent and band gap (Eg) values. Furthermore, we carried out comparative experiments on the photoconductivity performance of compounds 1-3 and their photocatalytic reduction from O2 to H2O2, indicating the significant influence of the energy level matching on the photocatalytic activity.

Oxygen vacancies-rich iron-based perovskite-like oxides LaxSr3-xFe2O7-δ (x = 0, 0.25, 0.5) have been studied towards application as both anode and cathode materials for symmetrical solid oxide fuel cells (SSOFCs) at intermediate temperatures utilizing their excellent thermo-chemical structural stability. The conduction mechanism of LaxSr3-xFe2O7-δ was investigated according to the effect of La content on electrical conductivity and oxygen nonstoichiometry. Consequently, LaxSr3-xFe2O7-δ was used simultaneously as reversible symmetrical electrodes for YSZ electrolyte supported SSOFCs with GDC buffer layers. The maximum power density of LaxSr3-xFe2O7-δ-GDC symmetrical electrodes increased from 350 mW cm−2 to 480 mW cm−2 at 800 °C, and the corresponding cell polarization resistance decreased from 0.18 Ω cm2 to 0.16 Ω cm2, respectively. The enhanced performance is attributed to the improved electrical conductivity and electro-catalytic activity by the partial substitution of Sr with La. These results demonstrate that new iron-based perovskite-like oxides are promising for applications in intermediate temperatures SSOFCs.

The Humen Forts, in Guangdong, were first built in the fifth year of Jiaqing dynasty (1801), and some of their bases were made using tabia. Modern inspection shows that the elastic modulus of some forts can reach 686.6 Mpa, a strength exceeding that of ordinary cement. To explore the fundamental cause of this high strength, we designed a set of comprehensive testing methods for the forts’ tabia, using XRD and ELISA, conducting TG-DSC, and so forth. The experiments were conducted through on-site testing, sampling, and laboratory research on seven sites to explore the influence of the original ratio of tabia on the material strength. And successfully discovered that the techniques and materials used in the construction of the forts were unlike, some areas feature sticky rice and protein as the main organic additives. These tests will provide a reference for further research on the production process of tabia and the preparation of protective materials for the Forts’ repair.

Carbon materials have attracted abundant attentions and been utilized widely as anodes in rechargeable Li+/Na+/K+ ions batteries. Regarding the various radius of alkali-metal-ions, reversible intercalation and deintercalation in interlayers of carbons requires different interplanar spacing. In this work, N-doped graphene with tunable interplanar spacing is synthesized using graphitic carbon nitride (g-C3N4) as precursor with the assistance of polyvinylpyrrolidone (PVP). The obtained tunable interplanar spacing in the range from 0.34 nm to 0.45 nm with enlarged values is mainly ascribed to the high nitrogen doping levels (9.98–33.7 at. %), especially to the pyrrolic nitrogen. Serving as the anode materials in lithium ions batteries (LIBs) and sodium ions batteries (SIBs), promising specific capacities of 1236 mAh g−1 for LIBs and 300 mAh g−1 for SIBs at current density of 0.05 A g−1 and excellent cycling stability as well as acceptable rate capability are demonstrated for the resultant N-doped graphene. The influences of interplanar spacing on the electrochemical performances of LIBs and SIBs are investigated comparatively. This work outlines a facial route to synthesize N-doped graphene with tunable interplanar spacing, meeting the various requirements unitized as anodes in rechargeable Li+/Na+/K+ ions batteries.

PM2.5 and its main chemical components have been investigated during six air pollution periods across four seasons from Jun. 16, 2016 to Jun. 15, 2017 at a suburban site in Beijing, China. Daily PM2.5 mass concentrations were measured with associated ions, OC, EC, 16 PAHs and seven heavy metals. Mass closure analyses were conducted using measured and reconstructed chemical components. Chemical ratios were used to identify possible pollution sources, while principal component analysis (PCA) coupled with multiple linear regression (MLR) method was used to estimate the source contribution to PM2.5 mass. The annual mean PM2.5 concentration (96.7 μg m−3) is about 2.8 times the national level-2 standard limit, with apparent seasonal variation of daily exceedances as winter > spring > autumn > summer. Generally, higher levels are observed in winter and autumn than in spring and summer for NO3−, SO42−, NH4+, Cl−, K+, OC, EC, PAHs and metals Zn, As, Cu, Pb, along with higher concentrations of NOx, CO and SO2. Secondary ions and carbon fractions are most abundant over all seasons, except levels of dust related species Ca2+, Mg2+, Ca, Fe and Mn are also high in spring. The reconstructed results show that PM2.5 consists of mostly organic compounds (26–38%) and ammonium salts (NH4NO3 + (NH4)2SO4) (43–53%) in winter and autumn, while summer is dominated mainly by ammonium salts (81%). In spring, very high PM2.5 episodes are occasionally composed of large amount of soil/road dust and gypsum particles (23–55%) due to floating dust events with drier weather conditions and human activities. Fuel combustions and secondary sources are responsible for ~70% of PM2.5 mass while mobile source is mostly a regional origin.

Zero-dimensional lead-free organic-inorganic hybrid metal halides have drawn attention as a result of their local metal ion confinement structure and photoelectric properties. Herein, a lead-free compound of (Gua)3Cu2I5 (Gua = guanidine) with a different metal ion confinement has been discovered, which possesses a unique [Cu2I5]3- face-sharing tetrahedral dimer structure. First-principles calculation demonstrates the inherent nature of a direct band gap for (Gua)3Cu2I5, and its band gap of ∼2.98 eV was determined by experiments. Worthy of note is that (Gua)3Cu2I5 exhibits a highly efficient cool-white emission peaking at 481 nm, a full-width at half-maximum of 125 nm, a large Stokes shift, and a photoluminescence quantum efficiency of 96%, originating from self-trapped exciton emission. More importantly, (Gua)3Cu2I5 single crystals have a reversible thermoinduced luminescence characteristic due to a structural transition scaled by the electron-phonon coupling coefficients, which can be converted back and forth between cool-white and yellow color emission by heating or cooling treatment within a short time. In brief, as-synthesized (Gua)3Cu2I5 shows great potential for application both in single-component white solid-state lighting and sensitive temperature scaling.

Solvothermal assembly of copper(II) cations and 5-(pyridine-3-yl)isophthalate linkers bearing different position-substituted methyl groups afforded four ligand-induced metal-organic framework (MOF) isomers as a platform for investigating diverse selective gas adsorption properties and understanding the positional effect of methyl functionality. Single-crystal X-ray diffraction (SCXRD) analyses showed that, when the methyl substituent is at the para position with respect to the pyridinic N atom, the resultant framework compound ZJNU-27 features an eea-type topology, while the other three solids possess an isoreticular structure with an rtl-type topology when the methyl group is situated at the other positions. As revealed by N2 physi-adsorption measurements at 77 K, they exhibit moderate specific surface areas ranging from 584 to 1182 m2 g-1 and distinct degrees of framework flexibility, which are heavily dependent on the methyl position. Comprehensive gas adsorption studies show that they are capable of effectively separating three pairs of binary gas mixtures including C2H2-CH4, CO2-CH4, and CO2-N2 couples. Moreover, their uptake capacities and adsorption selectivities can be tailored by altering the methyl position. In addition, their framework hydro-stability is also influenced by the methyl position. Compared to ZJNU-27 and ZJNU-28, ZJNU-26 and ZJNU-29 exhibit poorer stability against H2O, although the methyl group is more close to inorganic secondary building units (SBUs), which are believed to originate from the steric effect of the methyl group. Overall, the four MOFs display the methyl position-dependent network architectures, framework flexibilities, and selective gas adsorption properties as well as hydrostabilities. The findings observed in this work not only demonstrate the importance of the positional effect of the functional group but also highlight that engineering the substituent position is a potential strategy for achieving the modulation of MOF structures and properties.

There is increasing interest in understanding the role of airborne chemical components in modulating the cell cycle of human bronchial epithelial (HBE) cells that is associated with burden of cardiopulmonary disease. To address this need, our study collected ambient PM10 (particles with aerodynamic diameter less than or equal to 10 μm) and PM2.5 (particles with aerodynamic diameter less than or equal to 2.5 μm) across four sampling sites in Beijing during the year of 2015. Chemical components including organic carbon (OC), elemental carbon (EC), polycyclic aromatic hydrocarbons (PAHs), metals and water soluble ions were determined. Spearman's rank-order correlation was performed to examine the associations between chemical components in ambient particles and cell cycle distributions with p-values adjusted by Bonferroni methodology. Our results demonstrated the significant associations between certain chemical compositions (i.e., PAHs, EC, As and Ni) and percentages of HBE cells in G0/G1 and G1/G2 phases, respectively. Our results highlighted the need to reduce the specific toxins (e.g., PAHs, EC, As and Ni) from ambient particles to protect cardiopulmonary health associated with air pollution. Future study may focus on illustrating the mechanism of certain chemical compositions in altering the cell cycle in HBE cells.

Polyoxometalates (POMs) as molecule-based metal oxides have exhibited significant application in catalysis and materials science, but the synthesis of pristine POM nanomaterials still remains a challenge. In this work, we find a novel strategy of concentration-induced self-assembly for gaining pristine POM nanorods AgxH3−xPMo12O40 (denoted as AgHPMo12), which are synthesized only from both POMs and silver ion Ag+ in an aqueous solution at room temperature. The controllable concentrations of the cationic and anionic components in the aqueous solution become the critical factor for the successful synthesis. In addition, the photoelectric properties of AgHPMo12 nanorods were investigated as compared to those of AgHPMo12 particles, indicating a superior photoelectric performance of AgHPMo12 nanorods to AgHPMo12 particles. Furthermore, AgHPMo12 nanorods/phthalocyanine heterojunction photocatalysts were prepared for evaluating photocatalytic degradation of tetracycline hydrochloride, showing an efficient photocatalytic performance due to the advantages of the nanorods and type II heterostructure.

Soil organic matter (SOM) plays an important role in the field of climate change and terrestrial ecosystems. SOM in large areas, especially in urban areas, is difficult to monitor and estimate by traditional methods. Urban land structure is complex, and soil is a mixture of organic and inorganic constituents with different physical and chemical properties. Previous studies showed that remote sensing techniques that provide diverse data in the visible-near-infrared (VNIR)-shortwave infrared (SWIR) spectral range, are promising in the prediction of SOM content on a large scale. Sentinel-2 covers the important spectral bands (VNIR-SWIR) for SOM prediction with a short revisit time. Thus, this article aimed to evaluate the capacity of Sentinel-2 for SOM prediction in an urban area (i.e., Shanghai). 103 bare soil samples filtrated from 398 soil samples at a depth of 20 cm were selected. Three methods, partial least square regression (PLSR), artificial neural network (ANN), and support vector machine (SVM), were applied. The root mean square error (RMSE) of modelling (mRMSE) and the coefficient of determination ( $R^{2}$ ) of modelling $(mR^{2})$ were used to reflect the accuracy of the model. The results show that PLSR has the poorest performance. ANN has the highest modelling accuracy (mRMSE = 7.387 g kg $^{-1}$ , $mR^{2}=0.446$ ). The ANN prediction accuracy of RMSE (pRMSE) is 4.713 g kg $^{-1}$ and the prediction accuracy of $R^{2}~(pR^{2})$ is 0.723. For SVR, the pRMSE is 4.638 g kg $^{-1}$ , and the $pR^{2}$ is 0.732. The prediction accuracy of SVR is slightly higher than that of ANN. The spatial distribution of SOM demonstrates that the value obtained by ANN is the closest to the range of the bare soil samples, and ANN performs better in vegetation-covered areas. Therefore, Sentinel-2 can be used to estimate SOM content in urban areas, and ANN is a promising method for SOM estimation.

An insoluble small-molecule organic compound [N,N′-bis(2-anthraquinone)]-perylene-3,4,9,10-tetracarboxydiimide (PTCDI-DAQ) can be a high-performance cathode in Li-ion batteries (LIBs). In half cells, PTCDI-DAQ delivers a peak specific capacity of 229 mA h g−1, along with the good retention of 82% over 3 months. Meanwhile, PTCDI-DAQ can still hold a capacity of 46 mA h g−1 at 25 A g−1. By using the reduced state (Li4TP) of lithium terephthalate (Li2TP) as an organic anode in the all-organic Li-ion batteries (OLIBs), our OLIBs can realize a high-energy density of 296 W h kg−1cathode in the voltage range of 0.2–3.2 V and fulfill a long lifespan over 20 000 cycles. To the best of our knowledge, the comprehensive performance of our PTCDI-DAQ II Li4TP OLIBs is currently one of the best pure-organic LIBs in the world.

We describe an isothermal, single-reaction, and one-step method for signal-on quantification of terminal deoxynucleotidyl transferase (TdT) activity based on the periodic elongation and assembly of polythymine embedded activatable molecular beacon (PTA-MB) into DNA nanostructures. PTA-MB is easily designed according to the rule of the conventional molecular beacon (MB) but engineered with a polyT composed loop. Upon exposure to the specific target TdT, the MB is first elongated with an adenine-rich (A-rich) long chain so that it can then act as the anchoring substrate to capture many original PTA-MBs along its strand. Their unfolding contributes to preliminary fluorescence emission. Significantly, the assembled PTA-MBs can also be elongated and hybridized with residual free PTA-MBs for the second round of signal amplification. Accordingly, multiple rounds of elongation, assembly, and activation of initial PTA-MBs can lead to the formation of DNA nanostructures and induce a dramatically enhanced fluorescence signal for qualitative and quantitative evaluation of TdT activity. The final assay indicated a limit of detection (LOD) of 0.042 U mL−1 TdT and showed excellent selectivity for TdT versus other common enzymes. Moreover, the practical applicability was validated by direct/absolute quantification of TdT in real biological specimens and accurate monitoring of the activity of TdT pretreated by low/high temperature and heavy metal ions. These findings demonstrated that this functional PTA-MB and its unique assembly behavior is most likely to promote the study of oligonucleotide probe-based DNA assembly, providing a reliable, convenient, and universal platform for precise and point-of-care monitoring of various biomolecules.

The interface issue between Na and the NASICON solid electrolyte is recognized as the dominant reason for the growth of Na metal dendrites. In this work, aSnS2 ultra-thin layer is fabricated on the surface of the Na3Zr2Si2PO12 electrolyte by a fast (1 min) and convenient (air atmosphere) pyrolysis method. A mixed-ion-electron conductor layer consisting of Na–Sn alloy and Na2S constructed in situ through the reaction between the Na metal anode and SnS2 can not only build a continuous and tight bonding interface between Na3Zr2Si2PO12 and Na, but also realize the uniform and rapid transfer of charge and Na+ flux at the interface, resulting in a stable interface during the Na deposition/stripping process. The Na symmetric cell with a maximum current density of 0.9 mA cm−2 can be stably operated at 0.1–0.4 mA cm−2 with low overpotential for a long time at room temperature. The Na3V2(PO4)3|Na3Zr2Si2PO12–SnS2|Na solid-state battery delivers excellent capacity retention ratios and rate performance, profiting from the constructed stable interface. This work proposes a facial strategy for the improvement of interface design, driving the application of inorganic solid electrolyte in solid-state batteries.

In this paper, we performed electric field measurements in a nanosecond DBD breakdown in ambient air using the electric field induced second harmonic generation technique, with a temporal resolution of approximate 5 ns. The measurements are in a diffuse plasma, and the emission intensity of the plasma is captured using an ICCD camera. Results including the non-zero electric field offset before the breakdown and the electric field during the breakdown, are obtained. The influence of the voltage amplitude is also investigated.

Rogowski coils for fast pulse current measurement need sparse winding. However, sparse winding might make the coil distribution uneven and result in measurement error as the measured conductor is placed eccentrically or obliquely or if there is nearby current external to the coil. In this article, the induced electromotive force and the resulting measurement error are determined for nonuniform turn density along the bobbin. The interturn capacitance is related to the time response and is an important parameter, but its accurate calculation is difficult. A data-fitting method based on finite-element simulation modeling is proposed, and the interturn capacitance is calculated. The displacement current flowing through the gap of a shielding container would also introduce measurement error for high frequency. The error caused by the displacement current is derived, and the influencing factors are discussed.

During the later stage of stagnation in Z-pinch experiments, a current divergence phenomenon often occurs that downstream current (load current measured in a vacuum) declines slowly to zero, while upstream current (current measured outside vacuum) normally decays with quasi-sinusoidal oscillation. To investigate the formation mechanism of this current divergence, the possible abnormal discharge channels in vacuum are captured by optical imaging in this article. Both time integral image and time-resolved image show that current divergence is accompanied by the surface flashover on the vacuum insulator. The time-resolved images also verified that the time when downstream current starts slow decline corresponds to the time when surface flashover occurs. Surface flashover changes the circuit topology and forms the freewheeling branch of the load inductance $L$ . An equivalent circuit is also established to analyze the current divergence. The discharge channel with low resistance $R$ results in large time constant ( $L/R)$ and makes the downstream current drop slowly, while the external impedance can make the upstream current keep the waveform of oscillation attenuation even under the condition of internal flashover. Moreover, the influence caused by current divergence is discussed in the aspect of load voltage and the energy dissipation on generator. According to the simulation results, with an appropriate resistance, an additional branch can help protect the upstream components.

Fine control of nitrogen-doping in carbon materials is an urgent issue with great challenges for the applications in energy storage devices. In this work, nitrogen-doped hollow carbon spheres (NHCS) with tunable nitrogen-doping properties are synthesized by using graphitic carbon nitride (g-C3N4) nanosheets as precursor and Zinc powder as the template. A series of characterization techniques were performed to evidence the successful transformation of NHCS from g-C3N4. The nitrogen-doping level from 12.76 at.% to 27.82 at.% and the relative doping fractions of pyridinic-N, pyrrolic-N and graphitic-N for the g–C3N4–derived carbon materials can be easily tuned by controlling the synthetic temperatures. Serving as Li-ions battery anodes, the resultant NHCS delivers an acceptable initial discharge capacity of 1012.4 mAh g−1 under a current density of 0.1 A g−1 and a promising cycling stability (1064.5 mAh g−1 after 400 cycles) as well as an excellent rate performance (360 mAh g−1 at 10 A g−1). This work provides a facile gateway to synthesize high nitrogen-doped carbon materials applying to energy storage devices, from nitrogen-rich g-C3N4 precursor.

For the future Z-pinch accelerator, the radiation magnetohydrodynamics (MHD) simulation of the load is urgently needed to investigate its performance. Also, more accurate results can be obtained if a detailed generator model is coupled to the MHD model. However, because of the non-TEM modes in the monolithic radial transmission lines (MRTLs), the field-circuit coupling model for the generator is too complex to be coupled to the MHD model directly. Therefore, an indirect iterative method is proposed. In this method, the load is simplified to a resistor and an inductor connected in series. The iterative loop $n$ is: using the load current $I_{\text {load},n- 1}$ ( $t$ ) calculated in the previous loop, the MHD model calculates the load resistance $R_{\text {load},n}$ ( $t$ ) and load inductance $L_{\text {load}, n}$ ( $t$ ) in a complete calculation time and using the load parameters $R_{\text {load},n}$ ( $t$ ) and $L_{\text {load},n}$ ( $t$ ), the field-circuit coupling model calculates the load current $I_{\text {load},n}$ ( $t$ ) in a complete calculation time. The initial load current $I_{\text {load},n} = 0$ ( $t$ ) is obtained from the field-circuit coupling model connecting the 0-D model for the load. The loop continues until the load current converges. Using a simple drive source, the reliability of this method is proved and then it is used for the simulation of Z800 accelerator, a future Z-pinch accelerator, with wire array. After three iteration loops, the final parameters, such as the load current and radiation power are obtained. The indirect iterative method is useful for evaluating the load performance in a coupled load generator system without the need for a lot of code development on the already established MHD model.

In this work, sodium beta-alumina solid electrolytes with high β″-Al2O3 content and high density are synthesized through solid-state reaction method employing boehmite as alumina sources. The influences of sodium oxide dosage on the phase component, texture structure, and ionic conductivity as well as the application performances in sodium ions battery for the synthesized beta-alumina electrolytes are investigated in detail. High β″-Al2O3 content of 94.6% and density of 97.8% are obtained for the electrolyte sinters through adding suitable excess of Na2O content, owing to the compensation of Na loss and the formation of molten state during the high-temperature sintering process. High ion conductivity of 1.16 × 10−2 S/cm at 350 °C is recorded for the beta-alumina electrolyte sinters, resulting from its high β″-Al2O3 content and density. The resultant beta-alumina electrolyte applied in Na3V2(PO4)3/Na battery delivers an initial discharge capacity of 80.5 mAh g−1 at 0.5 C and a high capacity retention of 79.25% after 100 cycles.

Periphytic algae is a useful indicator of aquatic ecological conditions. We investigated the periphytic algae on natural substrate and the environmental variables at 44 sites on three river systems in the Weihe River Basin (WRB). A total of 84 species are identified, representing 37 genera. The most common genera were Navicula, Oscillatoria, Nitzschia, Scenedesmus, Cymbell, and Fragilaria. One-way analysis of variance (ANOVA) indicated significant differences among the three river systems in environmental variables (p < 0.05). Non-metric multidimensional scaling (NMDS) analyses also showed differences in periphytic algae communities in the three river systems (p < 0.05) and identified different dominant species in each river system. Canonical correspondence analysis (CCA) and Monte Carlo permutation tests revealed that nutrient concentration, WT, and altitude were the most important variables affecting the structure and distribution of periphytic algae communities. Chemical variables were the most accounted for environmental variables (12.5%), while physical variable and geographical factors (5.8% in total) play a relevant minor role. Our results demonstrate that Navicula pupula, Navicula radiosq, Nitzschia palea, and Nitzschia denticula, exhibiting wide ecological amplitude, are tolerant of high concentrations of nutrient pollution. Variation of periphytic algae communities in WRB is due to the combination of anthropogenic and natural factors including agricultural and domestic wastes water inputting, land use patterns, geology, climatic changes, and river hydrology. HIGHLIGHTS Structure and distribution of periphytic algae communities were investigated in the Weihe River Basin.; The gradient of organic pollution detected in environmental variables was the main gradient, and the periphytic algae responded to this gradient.; The types of substrates in river impact periphytic algae abundance, causing higher periphytic algae abundance in cobbles substrate.; The variation of periphytic algae communities is attributed to the combination of anthropogenic factors and natural factors.; The results support the periphytic algae as ecological indicators in the Weihe River Basin.

Readily available zinc alkyl complexes showed good activity and regioselectivity in catalyzing hydroboration and hydrosilylation of N-heteroarenes. Hydroboration of benzo-fused N-heterocycles gave exclusive 1,2-addition products in 80-97% yields. Reactions of pyridines afforded a mixture of 1,2-, 1,4-, and 1,6-products in yields of 55-95%, with 1,2-dihydropyridine as the main product. Bis-hydrosilylation was observed for quinoline derivatives, generating bis-1,2-hydrosilylation products in 76-96% yields. Kinetic studies and control experiments were conducted to gain some insights into the reaction mechanism.

Data and knowledge of the spatial-temporal dynamics of surface water area (SWA) and terrestrial water storage (TWS) in China are critical for sustainable management of water resources but remain very limited. Here we report annual maps of surface water bodies in China during 1989–2016 at 30m spatial resolution. We find that SWA decreases in water-poor northern China but increases in water-rich southern China during 1989–2016. Our results also reveal the spatial-temporal divergence and consistency between TWS and SWA during 2002–2016. In North China, extensive and continued losses of TWS, together with small to moderate changes of SWA, indicate long-term water stress in the region. Approximately 569 million people live in those areas with deceasing SWA or TWS trends in 2015. Our data set and the findings from this study could be used to support the government and the public to address increasing challenges of water resources and security in China., The authors of this study compile data on spatial and temporal dynamics of surface water bodies across China, covering a time span from 1989 – 2016. The study describes hot-spot areas with strongly decreasing trends in surface water area and terrestrial water storage in North China and discusses implications of water resources and security in China.

The bed nucleus of the stria terminalis (BNST) plays a critical role in regulating anxiety, yet the involved specific cell types and their connections functioning in anxiety-related behaviors remains elusive. Here we identified two cell subpopulations—corticotropin-releasing hormone-positive (CRH+) and protein kinase C-δ-positive (PKC-δ+) neurons—each displayed discrete emotionally valenced behaviors in the anterior-dorsal BNST (adBNST). Using whole-cell patch-clamp recordings and virus-assisted circuit tracing techniques, we delineated the local and long-range connectivity networks in a cell-type-specific manner. The results show that the CRH+ and PKC-δ+ neurons received inputs from similar brain regions and exhibited significant differences in the downstream projection density. In addition, in vivo calcium imaging as well as gain- and loss-of-function studies characterized the physiological response properties and the functional heterogeneities in modulating anxiety, further suggesting the similarity and individuality between the two adBNST cell types. These results provide novel insights into the circuit architecture of adBNST neurons underlying the functionally specific neural pathways that relate to anxiety disorders.

A numerical model is developed to evaluate ethanol-fueled solid oxide fuel cells (E-SOFCs) with a Ni-BaZr0.1Ce0.7Y0.1Yb0.1O3–δ (Ni-BZCYYb) external reformer owing to its high hydrophilia, carbon deposition resistance, and catalytic properties. This model is validated by the ethanol conversion and product selectivity with the introduction of the steam for adjusting the water-carbon ratio. The simulated E-SOFCs provide a suitable porosity and thickness for the Ni-BZCYYb external reformer, and the optimal control conditions are that the porosity is around 0.4, and the thickness is more than 4 mm for the best reforming effect, which can decrease the concentration polarization loss and improve cell performance. The carbon deposition boundaries and the equilibrium composition can be predicted by the thermodynamic equilibria calculation for E-SOFCs. The proposed model can give the optimization of the geometry design and operating conditions to avoid carbon deposition and improve the electrochemical performance of E-SOFCs.

In this paper, an error-ellipse-resampling-based particle filter (EER-PF) algorithm is proposed for target tracking in wireless sensor networks. In order to improve the effectiveness of the particles, in the process of resampling, the error ellipse of different confidence levels is established according to the error covariance matrix of particles. The particles are divided into different levels based on the geometrical position, and then the particles are screened and optimized. The effectiveness of the proposed method in a cumulative error optimization was verified by comparing with the performance of posterior Cramer-Rao lower bound (PCRLB). Experimental results show that the proposed algorithm can effectively solve the problem of sample degeneracy and impoverishment, and has higher positioning accuracy.

The preparation of high-efficient flame-retardant PLA remains a major challenge due to the unavoidable loss in mechanical properties. In this study, a DOPO derivative containing phosphorus and nitrogen in the molecular structure with amino as terminal group (DOPO-NH2) was incorporated into PLA to improve the flame resistance. The addition of this DOPO derivative on the thermal stability, flame retardancy and mechanical properties of PLA was investigated. With loading of only 5 mass% DOPO-NH2, the LOI value increased to 26% and UL-94 V-0 was attained. The heat release rate showed obvious decrease by microscale combustion calorimetry. Moreover, the mechanical properties of PLA/5DOPONH2 composite have not deteriorated significantly due to the low loading and the existence of hydrogen bond between DOPO-NH2 and PLA matrix.

Recently, low-dimensional organic-inorganic lead halide perovskites have attracted a great deal of attention due to their outstanding tunable broadband emission, while the toxicity of lead hinders their further application in the photoelectric field. Here, we report a novel lead-free Cu(I)-based organic-inorganic perovskite-related material of a (MA)4Cu2Br6 single crystal with zero-dimensional clusters, which is a unique Cu2Br64- corner-sharing tetrahedron dimer structure consisting of two connected tetrahedra. The single crystal displays a bright broadband green emission with a high photoluminescence with a quantum yield of ≤93%, a large Stokes shift, and a very long (microsecond) photoluminescence (PL) lifetime, resulting from self-trapped exciton emission. The direct band gap characteristic of (MA)4Cu2Br6 was proven by density functional theory calculation, and its band gap was determined by experiments to be ∼3.87 eV. In the temperature range of 98-258 K, the PL intensity increases gradually with an increase in temperature due to the deep trapping out of strong electro-phonon coupling, while the PL decreases when the temperature increases over 258 K due to phonon scattering. It is worth mentioning that this new material has high chemical and light stability, in contrast to the lead perovskite.

Coastal wetlands, composed of coastal vegetation and non-vegetated tidal flats, play critical roles in biodiversity conservation, food production, and the global economy. Coastal wetlands in China are changing quickly due to land reclamation from sea, aquaculture, industrialization, and urbanization. However, accurate and updated maps of coastal wetlands (including vegetation and tidal flats) in China are unavailable, and the detailed spatial distribution of coastal wetlands are unknown. Here, we developed a new pixel- and phenology-based algorithm to identify and map coastal wetlands in China for 2018 using time series Landsat imagery (2,798 ETM+/OLI images) and the Google Earth Engine (GEE). The resultant map had a very high overall accuracy (98%). There were 7,474.6 km(2) of coastal wetlands in China in 2018, which included 5,379.8 km(2) of tidal flats, 1,856.4 km(2) of deciduous wetlands, and 238.3 km(2) of evergreen wetlands. Jiangsu Province had the largest area of coastal wetlands in China, followed by Shandong, Fujian, and Zhejiang Provinces. Our study demonstrates the high potential of time series Landsat images, pixel- and phenology-based algorithm, and GEE for mapping coastal wetlands at large scales. The resultant coastal wetland maps at 30-m spatial resolution serve as the most current dataset for sustainable management, ecological assessments, and conservation of coastal wetlands in China.

2-hydroxy-N-(2-hydroxyethyl)-N-methylethanaminium methanesulfonate ([BHEM][mesy]) displayed good ability for separating cellulose from biomass material in previous works. In order to have a better understanding of the structure–property relationship and facilitate further potential applications in industry, it is necessary to obtain more data for the physicochemical properties of [BHEM][mesy] and its mixtures. In this work, the densities (ρ) and viscosities (η) of [BHEM][mesy] + solvents (water, methanol, ethanol, n-propanol and isopropanol) mixtures were measured at six temperatures from (298.15 to 323.15) K over the full molar composition range and fitted by an empirical quadratic equation and Vogel–Fucher–Tammann (VFT) equation. Moreover, the excess molar volumes (VE) and viscosity deviation (Δη) of five binary mixtures were calculated and correlated by the Redlich–Kister equation. In addition, the apparent molar volumes ($${V}_{\varphi }$$) and partial molar volumes ($$\stackrel{-}{V}$$) of [BHEM][mesy] and solvents were also calculated and all these physicochemical property data (density, viscosity, excess molar properties as well as the apparent molar properties) are discussed in terms of the structure and interaction of binary mixtures.

Polarization-sensitive photodetectors are highly desirable for high-performance optical signal capture and stray light shielding in order to enhance the capability for detection and identification of targets in dark, haze, and other complex environments. Usually, filters and polarizers are utilized for conventional devices to achieve polarization-sensitive detection. Herein, to simplify the optical system, a two-dimensional self-powered polarization-sensitive photodetector is fabricated based on a stacked GeSe/MoS2 van der Waals (vdW) heterojunction which facilitates efficient separation and transportation of the photogenerated carriers because of type-II band alignment. Accordingly, a high-performance self-powered photodetector is achieved with merits of a very large on-off ratio photocurrent at zero bias of currently 104 and a high responsivity (Rλ) of 105 mA/W with an external quantum efficiency of 24.2%. Furthermore, a broad spectral photoresponse is extended from 380 to 1064 nm owing to the high absorption coefficient in a wide spectral region. One of the key benefits from these highly anisotropic orthorhombic structures of layered GeSe is self-powered polarization-sensitive detection with a peak/valley ratio of up to 2.95. This is realized irradiating with a 532 nm wavelength laser with which a maximum photoresponsivity of up to 590 mA/W is reached when the input polarization is parallel to the armchair direction. This work provides a facile route to fabricate self-powered polarization-sensitive photodetectors from GeSe/MoS2 vdW heterojunctions for integrated optoelectronic devices.

In this work, the one- (OPA) and two-photon absorption (TPA) and transition characteristics of the porphyrin and fullerene donor–acceptor systems linked by thiophene oligomers are investigated theoretically. In the study of the transition characteristics of OPA and TPA, a combination of 2D and 3D visualization methods is used. During the OPA and TPA transitions of this D–A system, there is both superexchange charge transfer without thiophene oligomers and sequential charge transfer through thiophene oligomers. On this basis, there exist also charge recombination TPA excitations of the previous two kinds of charge transfer into an intrinsic process. The degree of polymerization of the thiophene oligomer significantly affects the efficiency of superexchange charge transfer and participates in excitation in units of quarter-thiophene. Finally, a method to enhance the charge transfer efficiency during TPA excitation is proposed, which is local excitation enhanced charge transfer excitation.

Early stage of underwater electrical wire explosion was observed by shadowgraph. By decreasing initial energy, the early stage of wire explosion was slowed down and possible to capture shadow photos during phase transitions. The vaporization process of wire is usually axially non-uniform due to random local micro explosions along the wire. The degree of non-uniform will be significantly decreased when increasing the initial energy. During explosion of the wire, more than one shock waves were generated not only from phase transition, but also from different pulses of deposition power. A modified piston model was introduced to explain the phenomenon.

In recent years, with the popularity of smartphones, mobile sensor technologies have been widely used in indoor localization. Its advantage is that data can be collected directly from smartphones without installing any other equipment. Meanwhile, it has the disadvantages of high requirements on positioning conditions and large deviations in positioning results. A technology of crowd-sourcing landmarks-assisted smartphone in indoor localization (CLS-IL) is proposed in this paper so as to solve these disadvantages. Firstly, the accelerometer, magnetometer and gyroscope sensors are used to acquire initial positioning of users. The characteristics of magnetometer and gyroscope sensors are analyzed through a series of experiments in allusion to the key problem of heading estimation errors, then corresponding data is matched for different experimental conditions. After that, the corresponding landmark database is established for experimental environment and an adaptive optimization algorithm of landmarks is proposed to correct drift errors caused by the readings of sensors influenced by surrounding environment and long positioning time excessively during traditional pedestrian dead reckoning. Experimental results show that the location accuracy of CLS-IL system is significantly improved compared with traditional technologies, which provides strong support for subsequent studies.

A cost-effective chromatic dispersion (CD) estimation method is proposed, which is based on the delay-tap sampling (DTS) technique in combination with periodic training sequences (PTS). By performing equivalent sampling of PTS, DTS-based CD estimation at ultra-low sampling rate can be realized, significantly reducing the cost and high-speed requirements of analog to digital converters (ADCs). In contrast to the existing Nyquist DTS-based CD estimation method, we construct the CD lookup table in the CD over-compensated region, which can be suitable for a dynamic range of OSNR conditions. The CD lookup table built from the simulation can be used in the experimental system with similar configurations directly, indicating that the suggested method is reasonable and highly feasible. Besides, with only 1.25 GSa/s sampling rate of ADCs (about 1/30 of the Nyquist sampling rate which is 40.28 GSa/s), both 20.14 GBaud quadrature-phase-shift-keying (QPSK) simulation and experimental systems demonstrate the feasibility of the method, with a 28 ps/nm maximum CD estimation error for the simulation and a 35 ps/nm maximum CD estimation error for the experiment when OSNR is fixed to 18 dB. Furthermore, we also investigate the robustness of our method under the condition of different amplifier spontaneous emission (ASE) noise and nonlinear noise. The proposed method shows great potential for making a remarkable cost reduction in CD monitoring.

Vigilance is an important antipredation technique that can be affected by many factors, such as body size and group size. Small animals are more vulnerable than large ones, so the former are expected to behave more vigilantly than the latter. This effect of body size on vigilance may occur inter- or intraspecifically. We studied the vigilance behavior of two sympatric wild ungulates, Tibetan antelopes (Pantholops hodgsonii) and Tibetan gazelles (Procapra picticaudata). Tibetan antelopes, with a body size of 33 kg are much larger than Tibetan gazelles, with a body size of approximately 14 kg. Tibetan antelopes are sexually and body-size dimorphic; that is, males are much heavier than females. Alternately, Tibetan gazelles are sexually dimorphic but the sexes do not differ in weight. Tibetan gazelles scanned their environment more frequently than Tibetan antelopes did. Small female Tibetan antelopes scanned their environment more frequently than males did, whereas male Tibetan gazelles scanned their environment more frequently than females did. Group size did not affect the vigilance of Tibetan gazelle, but its negative effect on the vigilance of male Tibetan antelopes was marginally significant. In female Tibetan antelopes, vigilance in large groups was high probably because of scramble competition and social monitoring. Our results suggested that body mass and group size play an important role in shaping the vigilance of these two rare Tibetan ungulates.

This paper thoroughly investigates the decomposition pathways of SF6 in the presence of organic insulator vapors by means of high level quantum chemistry calculations with density functional theory. Optimized molecular structures and vibrational frequencies of intermediate products (IM) and transition states (TS) are first reported in this work. Potential energy surface is then investigated with a more sophisticated CCSD method including zero-point energy corrections and the rate constants are calculated with transition state theory. The overall chemical decomposition pathways of SF6 + PTFE vapor are obtained which are consisted of 17 reactions with TS1–TS17. By analyzing the rate constants, reactions SF + C → S = CF → TS2 → F + SC, SF3 + C → TS7 → SF2CF → TS8 → SFCF2, SF4 + C → IM3 → TS11 → IM4 → SF3 + CF and SF5 + C → IM5 → TS15 → SF4 + CF are selected as main reactions in SF6 decomposition. The results are prerequisite to study the non-equilibrium compositions of SF6 + organic insulator vapor mixtures.

For green synthesis in organic phases, the catalysis of lipases needs to be further improved. Here a strategy is to simulate the activation of lipases at water/oil interface by immobilizing lipase on an available carrier material, which can replace the water at the interface to stabilize enzyme against denaturation from organic phase. The carrier is selected as cotton fiber on which Pseudomonas cepacia lipase is immobilized by physical adsorption in a column glass bottle to form a simple bioreactor together with the bottle. In synthesis of fragrance ester hexyl acetate via transesterification of hexanol with vinyl acetate, the bioreactor exhibits a 3-fold increase in the ability to transform substrate, relative to native lipase in terms of the initial period of reaction at 37°C and 160 rpm. And also the bioreactor is very stable in catalysis for that it has an extra long half life t1/2 = 636 h, calculated from the decrease degree of molar conversions in six times of 6-hour transesterifications. More interestingly, the bioreactor behaves excellent activity at room temperature and in a static state, and can transform nearly 100% hexanol after 48 h. All these indicate that the bioreactor has great potential for industrial application.

The viral capsid protein p24 of human immunodeficiency virus is expressed at different level during viral invasion. Detection of p24 is of great importance in acquired immunodeficiency syndrome monitoring and therapy. A ratiometric probe that is easily-synthesized was constructed based on self-assembled fluorescent Ce(Ⅲ) and fluorescein. Fluorescein was used as reference. Hydrogen peroxide quenches the fluorescence of the Ce(III) easily but does not quench the fluorescence of fluorescein. The mechanism of reaction was discussed. Benefiting from the sensitive response to hydrogen peroxide, this probe was applied for p24 detection in enzyme linked immunoassay. The fluorescence ratio was in a good linear relationship with the concentration of p24, and the detection limit was 1.1 pg mL−1. This proposed method has shown potential in virus detection with easy operation.

A lead-free compound, (TBAC)SnCl3 (TBAC = tetrabutylammonium chloride), with high anti-water stability was reported, which can be stable in water for 24 hours. Upon photoexcitation, this compound exhibits a green photoluminescence (PL) centered at 523 nm with a larger Stokes shift of 260 nm at room temperature (RT), stemming from self-trapped exciton (STE) emission.

Based on fractal theory, a regular fractal is used to construct symmetrical reef models (e.g., cube and triangle reef models) with different fractal levels (n = 1, 2, 3). Using the concept of fractal dimension, we can better understand the spatial effectiveness of artificial reefs. The void space complexity index is defined to quantify the complexity of the internal spatial distribution of artificial reefs models under different levels. The computational fluid dynamics (CFD) flow simulation approach was used to investigate the effects of void space complexity on the flow field performances of the symmetrical artificial reef models. The upwelling convection index (Hupwelling/HAR, Vupwelling/VAR), wake recirculating index (Lwake/LAR, Vwake/VAR) and non-dimensionalized velocity ratio range were used to evaluate the efficiency of the flow field effect inside or around artificial reefs. The surface area and spatial complexity index of artificial reefs increase with increasing fractal level. The numerical simulation data shows that the Menger-type artificial reef models with a higher spatial complexity index have better flow field performances in the upwelling and wake regions. Compared to the traditional artificial reef models, the upwelling convection index (Vupwelling/VAR) and recirculating index (Vwake/VAR) of n = 3 fractal cube artificial reef increase by 37.5% and 46.8%, respectively. The efficiency indices of the upwelling region and wake region around the fractal triangle artificial reef model are 2–3 times those of the fractal cube artificial reef model when the fractal level is 3.

Highly active triple-conducting (proton-, oxygen-ion-, and electron-conducting) perovskite oxide BaCo0.4Fe0.4Zr0.1Y0.1O3-δ need to further optimize the electrochemical performance and chemical stability in carbon dioxide and water containing atmospheres, greatly limiting its widespread use in protonic ceramics fuel cells (PCFCs). Here, Ba-site deficient Ba0.9Co0.4Fe0.4Zr0.1Y0.1O3-δ (B9CFZY) was synthesized and investigated as a promising candidate concerning the chemical and structural stability, electrical conductivity and electrochemical performance. Anode-supported button cells with the prevalent BaZr0.1Ce0.7Y0.2O3-δ (BZCY) as electrolyte using B9CFZY and B9CFZY-BZCY cathodes, respectively, were fabricated and then measured at 700-550 °C. The maximum power density of the cells with B9CFZY-based cathodes increase from 452 mW cm−2 to 537 mW cm−2 at 700 °C, however, the corresponding polarization loss decreases from 0.30 to 0.15 Ω cm2 by adding proton-conducting BZCY. Importantly, to better explore the reasons for the improved electrochemical performance, the distribution function of relaxation time (DRT) is used to distinguish different electrode polarization processes of both cells. The results indicate the polarization peaks (P3) of cells with composite cathode resulting from oxygen gas adsorption and dissociation can be greatly accelerated as well as the polarization peaks (P2) resulting from oxygen species diffusion to three phase boundaries or active sites in the cathode. The dramatic improvements demonstrate Ba deficient B9CFZY-BZCY material can be a very competitive cathode material for PCFCs.

The relative vibration between the micro-milling cutter and workpiece influences the processing quality and tool life. To solve the difficult problem of measurement of vibration displacement between cutting tool and workpiece during micro-milling process, we designed a laser displacement sensor holder, which realizes the adjustment on multi degrees of freedom. A set of vibration displacement measurement system is developed, which utilizes laser displacement sensor to collect vibration signal during micro-milling process. The frequency of micro-milling force is obtained by using varying cutting parameters method. The relationship between cutting force amplitude, frequency and vibration displacement is ascertained by using neural network method to realize vibration displacement prediction under given cutting parameters. The research lays the foundation for vibration suppression of micro-milling, which can help improve surface quality and extend tool life.

This research is aimed to understand the heat transfer and fluid flow of the arc plasma and weld pool with a significant deformation of the weld pool surface during high current gas tungsten arc welding (GTAW). A unified model including the tungsten electrode, arc plasma and the weld pool of low carbon steel is developed by presetting a free surface deformation from the experimental observations. Buoyance, Lorentz force, plasma drag force and Marangoni force are taken into account to investigate the weld pool dynamics with a great depressed free surface. Heat flux, current density, Marangoni force and plasma drag force at the weld pool surface are presented to understand the heat and momentum transfer from the arc plasma to the weld pool. It is found that the distributions of the heat flux and current density as well as temperature at the depressed weld pool surface are double-peak profiles; the molten metal flow of the weld pool with severe surface depression are determined by the plasma drag force rather than the Marangoni force. The effect of the Lorentz force is more important than that of the buoyance, but weaker than the Marangoni force. The results are consistent with the existing results of both the experiment and the theory.

For the calculation of near-field acoustic waves generated by a relatively long arc, the spatial distribution of arc power density should be taken into account. An electrosound combined simulation of the ac arc was conducted. First, the arc was numerically simulated based on the 2-D MHD model. It was found that the spatial distribution of electric power density in the arc was highly nonuniform with significantly higher power density in the region close to the electrodes. Then, the acoustic wave generated by the arc was numerically simulated with the sound sources, taking the obtained distribution of arc power density into account. It was found that dP/dt , the derivative of arc power, was an important parameter that determined the sound pressure. The waveform of sound pressure was exactly of the same shape as that of dP/dt and the amplitude of sound pressure was proportional to that of dP/dt . The acoustic wave obtained by the simulation agreed well with the experimentally measured one. The dependence of the wave pressure on the propagating distance was compared to that of the spherical wave based on a monopole sound source, which confirmed the necessity of the electrosound combined simulation.

Indium selenide (InSe) is a promising two-dimensional photodetector material. However, the photogenerated electron-hole pairs are easy to recombine in simplex InSe semiconductor. Here, we design InSe-based van der Waals heterostructure, InSe/antimonene (β-Sb), based on first-principles. InSe/β-Sb heterostructure possesses intrinsic type-II electronic structure. Simultaneously, the work function of InSe (β-Sb) layer is −5.7 eV (−4.5 eV) which also promotes electrons transfer. In addition, the good optical absorption performance of InSe and β-Sb sublayer is preserved in the heterostructure. Moreover, different stacking mode between InSe/β-Sb does not affect the efficient carrier separation which is convenient to the application of optoelectronics.

Using first-principles calculations, we study the growth process of bismuth (Bi) films on Cu (111) substrate. By analyzing the formation mechanism of single layer α‑bismuthene and stability of multilayered Bi layers, we reveal that Bi atoms show quasi-one-dimensional growth model by developing periodic zigzag chains, and eventually form a Bi atomic layer on Cu (111) surface. Flat surface α‑bismuthene (Fα-Bi) can be formed by depositing two Bi atomic layers on Cu (111) and maintains its stability below 60 K. In the multilayered Bi atomic layers, the stability of Bi films shows an oscillatory behavior. It is more stable for Bi films with even layers. The charge density between even and odd films shows that the stability is associated with the saturation of pz orbital of Bi atoms. Besides, the distorted surface α‑bismuthene (Dα-Bi) can maintain its stability up to 450 K on Cu (111) surface. Further study shows that the Cu substrate strongly affects the properties of Fα-Bi than that of Dα-Bi. Our studies provide guidance for fabricating stable Bi (110) thin films based devices.

The pad front-end board (pFEB) and the strip front-end board (sFEB) are developed to read out signals from pads, wires, and strips of the sTGC detector for the ATLAS Phase-I Trigger Upgrade. The pFEB is used to gather and analyze pad trigger, and the sFEB is developed to accept the pad trigger to define the regions-of-interest for strips readout. The performance of p/sFEB must be confirmed before it is mounted on the sTGC detector. We present a scanning test system that is designed according to the test items of the p/sFEB. In the test system, a test pulse board is applied to generate different types of signals to the p/sFEB. The PC software and field-programmable gate array Xilinx analog-to-digital converter cooperate to achieve the scanning test of the analog parameter. At present, the system is utilized for the p/sFEB prototype performance test.

Ultrathin c-Si solar cells with their active layer thicknesses ranging from a few micrometers to several tens of micrometers will play a very important role in reducing the material costs of industrial c-Si solar cells. This work presents a new high efficiency light trapping scheme (HE-LTS) with two cavities for ultrathin c-Si solar cells. By analyzing the variations of the important optical parameters of each light trapping unit with its geometric parameters, the light trapping performances of the HE-LTS have been optimized. The results show that the light trapping abilities of the HE-LTS can exceed obviously that of Lambertian LTS in a broad range of geometric parameters for both TE and TM modes; the photocurrent densities of an ultrathin c-Si solar cell with the optimal HE-LTS can reach 36.65 mA/cm2 and 40.47 mA/cm2 for the TE and TM modes, respectively.