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This paper provides an intriguing electronic and magnetic properties of the Perovskite solar cell materials (MAPbI3, CsGeI3) which are analyzed by using density functional theory, where MAPbI3 is the abbreviation of CH3NH3PbI3. Herein, we mainly discuss the influence of ferromagnetism and antiferromagnetism on the crystal structure, band gap and electronic density of states of perovskite (MAPbI3) (CsGeI3). The magmom values of the applied magnetic field are from −6 μB to 6 μB, respectively (The negative sign here represents the opposite direction of the original magnetic field). The lattice parameters and volume of the crystal under different magnetic fields are obtained. It can be seen from the free energy that the stability of the crystal is compared with non-magnetic field, when the applied magnetic fields are at 4 μB and 5 μB, the free energy of the crystal is the lowest and its relative stability is better. At the same time, the magnetic field of CsGeI3 increases from −5 μB to 5 μB. The results show that the density of states of CsGeI3 moves towards the direction of higher energy, and the change of MAPbI3 crystal is more obvious. Similarly, we should pay attention to that when applying a magnetic field to the crystals, it is found that the band gap of both MAPbI3 and CsGeI3 decreases obviously after increasing the magnetic field, which avoids the situation of spin up and spin down overlap of MAPbI3, which is helpful to adjust the band gap size. From the perspective of crystal spectral absorption characteristics, when considering the ferromagnetic effect on CsGeI3 with the magnetic moment of a single atom is set to (1 μB, 2 μB, 3 μB, 4 μB, 5 μB, 6 μB), the width of absorption spectrum tends to decrease, but the impact on MAPbI3 is small.

In the information age, technology has changed people's lives as well as working and learning styles. The teaching competency of vocational teachers’ is facing new challenges. Based on the modernization of vocational education, "Internet + Vocational Education", and "reform of teachers, teaching materials and teaching methods", the study intends to enrich the research on vocational teachers’ teaching competency theoretically by establishing the framework, criteria and assessing instrument. In practice, the study aims to provide benchmarks and tools for the diagnosis and assessment of vocational teachers’ teaching competency. Furthermore, the study wishes to provide guidelines for vocational teachers' professional development and improve the quality of the ICT teaching practice.

Newport Inc. was licensed recently by the National Renewable Energy Laboratory of the United States to update the highest efficiency of the perovskite solar cell (PSC) certification of PSCs by 23.7%. Exploring new hole transfer layer is the key to the future development of PSC. In this paper, we constructed seven organic hole transport material molecules such as copper-phthalocyanine (CuPc), 2',7'-bis(bis(4-methoxyphenyl)amino)spiro[cyclopenta-[2,1-b:3,4-b']dithiophene-4,9'-fluorene] (FDT), Poly-triarylamine (PTAA), poly(3,4-ethylenedioxy thiophene)/poly(styrenesulfonate) (PEDOT/PSS) poly(3-hexylthiophene) (P3HT) and six in-organic hole transport material molecules such as CuCSN, CuI, InCuS2, CuO, Cu2O, NiO with Material Studio software. By the structure optimization, their energy band, density of state (DOS), HOMO/lowest unoccupied orbit (LUMO) energy level and absorption spectrum were calculated. Furthermore, the HOMO/LUMO electron cloud distribution map of FDT molecule was analyzed in detail. The results show that the electron cloud is closer to the nucleus with the increase of the isopotential surface value. From the absorption spectra, the absorption wavelengths of most inorganic hole transport materials are mainly concentrated at about 200 nm, which is relatively short. But the absorption wavelengths of organic hole transport materials are distributed in long wavelength region, most of them are above 2000 nm. Only the absorption spectra of PTAA, Spiro OMetad and CuPc are in the range of solar spectrum. The HOMO energy levels of seven organic hole transport materials are slightly higher than the values of valence band of CH3NH3PbI3 and NH2CH = NH2PbI3, which are favorable for carrier injection and transport. The band gap of inorganic hole transport materials CuCSN and CuI is wider. From the energy band structure curve, the effective mass of NiO, CuO, Cu2O carriers is smaller, which the carrier transport rate is relatively high. The hole transport material must have high hole mobility and hole conductivity so as to ensure the effective transport of the hole at the interface between the hole transport layer and the perovskite layer.

The electron-transport layer in planar perovskite solar cells plays an important role in improving photoelectric conversion efficiency. At present, the main electronic transmission materials in perovskite solar cells include TiO2, ZnO, WO3, ZrO2, SnO2, ZnO2, etc. This work mainly studies the electron-transport characteristics of six different electron-transport layers in perovskite solar cells. Based on the density functional theory, the electron-transport model of a solar cell doped with formamidinium iodide lead compound perovskite under six different electron-transport materials was constructed, and their effective electron mass and the mobility of carriers were obtained by optimizing the structure and theoretical calculation. The results show that the mobility of electrons in TiO2 crystal is slightly higher than that of FA0.75Cs0.25Sn0.5Pb0.5I3 carriers. Because of their high matching degree, it can be reasonably explained that titanium dioxide has been widely used in perovskite solar cells and achieved higher photoelectric conversion efficiency. In addition, the mobility of carriers in WO3 and SnO2 crystals is also high, so they also have great advantages in carrier transport. Due to its abundant, nontoxic, and low-pollution content, TiO2 has become the most widely used electronic transmission layer material for solar cells. Furthermore, we have explored eight new semiconductor materials that have not yet been used in perovskite solar cells as the electron-transport layer. The calculation results show that Ta2O5 and Bi2O3 are promising materials for the electron-transport layer. This study provides a theoretical basis for seeking better electronic transmission materials for solar cells in the future.

In the paper, the structures, pressure-induced structural transitions (from cubic to hexagonal), lattice dynamics and the possible transition mechanisms for rare earth dihydrides REH2 and trihydrides REH3 (RE = Sm, Gd, Tb, Dy, Ho, and Tm) are investigated comparatively and systematically using first-principles calculations. The transition pressures from the cubic CaF2-type structure to the hexagonal REB2-type structure for REH2 (RE = Sm, Gd, Tb, Dy, Ho, Tm) and the transition pressures from the cubic BiF3-type structure to the hexagonal LaF3-type structure for REH3 (RE = Sm, Gd, Tb, Dy, Tm) are predicted reasonably. It is concluded that the two kinds of structural phase transitions are not sensitive to RE 4f electrons. In the two kinds of structural phase transitions under pressure, we note that the ‘‘2.1 A rule’’ (the purposed minimum H H distance for the stable metal hydirde at 0 K and 0 GPa) doesn't work. While lattice dynamics show that the dynamical stable pressure ranges for the cubic REH2 (RE = Sm Gd, Tb, Dy, Ho, Tm) are about in 0–52, 0–60, 0–70,0-87, 0–94 and 0–108 GPa, respectively. Ones of the cubic REH3 (RE = Sm, Gd, Tb, Dy, Tm) are around 17–147, 31–182, 13–200, 16–224 and 14–280 GPa, respectively. In contrast to the corresponding structural transition pressure as well as the lattice dynamics of the hexagonal structure under high pressure, the phonon modes softening behaviors under pressure might be responsible for the pressure-induced structural phase transition in the cubic REH2, but not in the cubic REH3.

CsGeI3 has been widely studied as an important photoelectric material. Based on the density functional theory (DFT), we use first-principles to study the photoelectric properties of CsGeI3 by applying successive hydrostatic pressure. It has been found that CsGeI3 has an optimal optical band gap value of 1.37 eV when the applied pressure is &minus, 0.5 GPa, so this paper focuses on the comparative study of the photoelectric properties when the pressure is &minus, 0.5 GPa and 0 GPa. The results showed that CsGeI3 has a higher dielectric value, conductivity, and absorption coefficient and blue shift in absorption spectrum when the pressure is &minus, 0.5 GPa. By calculating and comparing the effective masses of electrons and holes and the exciton binding energy, it was found that their values are relatively small, which indicates that CsGeI3 is an efficient light absorbing material. CsGeI3 was found to be stable under both pressure conditions through multiple calculations of the Born Huang stability criterion, tolerance factor T, and phonon spectrum with or without virtual frequency. We also calculated the elastic modulus of both pressure conditions and found that they are both soft, ductile, and anisotropic. Finally, the thermal properties of CsGeI3 under two kinds of pressure were studied. It was found that the Debye temperature and heat capacity of CsGeI3 increased with the increase of thermodynamic temperature, and the Debye temperature increased rapidly after pressure, while the heat capacity slowly increased and finally stabilized. Through the calculation of enthalpy, entropy, and Gibbs free energy of CsGeI3, it was found that the Gibbs free energy decreases faster with the increase of temperature without applied pressure, which indicates that CsGeI3 has a higher stability without pressure. Through the comparative analysis of the photoelectric properties of CsGeI3 under pressure, it was found that CsGeI3 after applied pressure is a good photoelectric material and suitable for perovskite solar cells (PSCs) material.

This study aimed to identify the potential and mechanisms of microbubble-mediated cavitation in promoting apoptosis and suppressing invasion in cancer cells. AsPC-1 cells were used and divided into four groups: control group, microbubble-only (MB) group, ultrasound-only (US) group, and ultrasound combined with microbubbles (US+MB) group. Pulse ultrasound was used with a frequency of 360 kHz and an intensity of 0.7 W/cm2 for 1 min (duty rate=50%). Then cells in four groups were cultured for 24 h. Cell counting kit‑8 illustrated that US+MB could decrease cell viability. Western blot confirmed that US+MB increased cleaved Caspase‑3, Bcl-2-associated X protein (BAX), and decreased the B‑cell lymphoma‑2 (Bcl-2) levels. Besides, US+MB increased intracellular calcium ions and down-regulated cleaved Caspase-8. For proliferation ability, cells in US+MB group had a lower expression of Ki67 and the weakened colony formation ability. The transwell invasion assay showed that US+MB could decrease invasion ability in AsPC-1 cells. Further evidence showed that cells conducted with US+MB had the lower level of hypoxia-inducible factor-1α (HIF-1α) and Vimentin and the higher expression of E-cadherin than the other three groups. Finally, cells conducted with US+MB had less invadopodia formation. In conclusion, these results suggested that microbubble-mediated cavitation promoted apoptosis and suppressed invasion in AsPC-1 cells.SignificanceCancer cells have a high rate of cell division and a high rate of cell division can speed up the development of hypoxia which lead to promote cancer invasion and metastasis. Here we used microbubble-mediated cavitation to generate a mechanical shock wave which could effectively kill cancer cells through physical damage and intrinsic signaling pathway. Furthermore, effective killing of cancer cells could restrain the development of hypoxia and prevent invasion ability of cancer cells.

The photoelectric conversion efficiency of perovskite solar cells has improved rapidly, but their stability is poor, which is an important factor that restricts their commercial production. This paper studies the physical and chemical stability of perovskite solar cells based on first principles. It is well known that methylamido lead iodide compounds and methylamino lead iodide compounds are easily degraded into NH2CHNH2I, CH3NH3I and PbI2. First, the chemical stability of the above two perovskite-type solar cell materials is discussed by calculating the binding energy. Then, their phonon scattering lines, state density and thermodynamic properties are calculated and analyzed, and the work functions of different types of crystals along different planes such as [1 0 0], [0 1 0 0], [0 0 1] and [1 1 1] are calculated. The results show that the work function of the methylamine iodized lead compound is greater than that of the methylamidine iodized lead compound, which means that the electrons of the methylamidine iodized lead compound escape more easily and the carrier transfer efficiency is higher under the same conditions. Finally, the effects of different temperatures, different electric fields and light on the two kinds of crystal materials are analyzed. This provides theoretical guidance for us to improve the stability of perovskite materials experimentally.

Cavitation greatly affects the ice blockage performance of propellers in polar areas, while the combined effect of cavitation and ice blockage on propellers has rarely been considered. In this work, the propeller model test in the cavitation tunnel and the viscous flow CFD numerical simulation based on RANS were conducted. In the cavitation tunnel test, the ice blockage model was simulated by a water-insoluble rectangular solid block, and the ice blockage was measured by the distance between the solid block and the propeller. The thrust and torque in tests and simulations were discussed under the uniform flow and ice blockage scenarios, as well as the variation of cavitation excitation force, pressure distribution of blades, cavitation characteristics and vortex intensity with advance coefficient when σn = 1.5, L/D = 0.15 in an ice blockage environment. The research shows that the numerical simulation results based on overlapping grids are in good agreement with the model test results, and the mean hydrodynamic errors are within 5%. In the uniform flow test, when the advance coefficient is small, the thrust and torque of the propeller will experience a sharp drop due to the influence of heavy cavitation. In the ice blockage test, the thrust and torque increase with the decrease of ice-propeller spacing, and the ice blockage becomes more serious as the cavitation grows. The propeller oscillates violently due to the cavitation excitation force, and the oscillation frequency increases with the increase of the advance coefficient. The cavitation is generated in the low-pressure area of the suction surface, and the cavitation shape captured in the present numerical simulation is consistent with the experimental phenomenon. Since the cavitation reduces the contact area between the water and the blade, the vortex strength will be reduced for the attachment of cavitation, and the vortex strength increases with the increase of the advance coefficient. This study will explore more hydrodynamic regularities with ice-class propellers in an ice blockage environment when cavitation occurrs, and provide technical support for the design of propellers of polar ships.

Introduction Patients with type 2 diabetes (T2D) receiving premixed insulin often fail to achieve optimal glycemic control. The insulin injection technique (IT) itself may be one of the factors affecting glycemic variability (GV). The aim of this study was to assess the relationship between GV and IT in patients with T2D using premixed insulin. Methods This was a single center, cross-sectional, and self-controlled trial. Patients with T2D using premixed insulin were enrolled as inpatients. The 4-day study consisted of a 2-day patient insulin injection period (days 0 and 1) and a 2-day specialist nurse insulin injection period (days 2 and 3). Patient insulin IT were assessed on day 1 by two independent nurses using a skill-related scale consisting of 15 items, with a maximum score for each item of 2 and a total optimum score of 30. All patients underwent 96-h continuous glucose monitoring (CGM) during the 4-day study, and CGM data collected on days 1 and 3 were recorded and analyzed. The primary outcome was the relationship between the insulin IT score and the 24-h mean amplitude glycemic excursion (MAGE) during the patient injection period. Results A total of 52 inpatients with T2D who used premixed insulin were recruited and completed the study. The mean total insulin IT score of these patients was considerably lower than the optimum score (17.0 ± 4.4 vs. 30). Our CGM data showed that the MAGE was significantly higher during the patient injection period than during the nurse injection period (P

In this study, near infrared spectroscopy has been demonstrated to quickly determine the saponin content in soapnut fruits. Partial least squares analysis combined with pre-processing methods and significance multivariate correlation variable selection was introduced to develop a statistical model calibrated for saponin content in soapnut fruits. The results showed that the first derivative yielded the best partial least squares calibration models with spectra of both the surface of dried fruits and the powder of dry seeded fruits with root mean square error of calibration values of 0.85% and 0.59%, respectively. The surface model presented less accuracy than the powder model. However, when the significance multivariate correlation variable selection method was applied to select the best variables from the spectra, the partial least squares models using spectra of surface and powder samples became similar, with higher R2 values (0.84 and 0.90), lower root mean square error of calibration values of 0.23% and 0.39%. It was suggested that near infrared spectroscopy could be a promising and rapid method for predicting the saponin content in the soapnut fruits without grinding them into powder.

With oil and gas exploitation developing towards deep-water fields, the extreme, low-temperature, and high-pressure environments are ideal for hydrate formation in subsea pipelines. Hydrate formation, growth, aggregation, and deposition in the flowlines substantially increase the hydrate blockage risk, necessitating the assessment and clarification of this process. This work employed computational fluid dynamics (CFD) and the discrete element method (DEM) to perform several numerical simulations using Fluent and EDEM to study the hydrate blockage process caused by aggregation and deposition. A three-dimensional model of a solid-liquid pipeline containing hydrate particles was established, which considered the cohesion force between the hydrate particles and the adhesion force between the hydrate particles and pipe wall. Two simulation strategies were implemented. The first simulated the hydrate blockage process using a throttling element, which assumed hydrate depositions on the pipeline wall. The second studied the impact of the collision between upstream and downstream hydrate aggregates. The critical hydrate blockage state was roughly defined based on the hydrate volume fraction and pressure drop changes during the hydrate aggregate collision process. These results represented the initial work for simulating the hydrate blockage process via combined CFD-DEM by considering the bidirectional interaction between the continuous water phase and discrete hydrate particles. These preliminary findings provided theoretical support for studying the hydrate blockage mechanism to solve the hydrate flow assurance issue in the subsea pipelines.

Plasma is an efficient method that can activate inert molecules such as methane and carbon dioxide in a mild environment to make them reactive. In this work, we have prepared an AE-NiO/γ-Al2O3 catalyst using an ammonia-evaporation method for plasma promoted dry reforming reaction of CO2 and CH4 at room temperature. According to the characterization data of XRD, H2-TPR, TEM, XPS, etc., the AE-NiO/γ-Al2O3 catalyst has higher dispersion, smaller particle size and stronger metal-support interaction than the catalyst prepared by the traditional impregnation method. In addition, the AE-NiO/γ-Al2O3 catalyst also exhibits higher activity in dry reforming reaction. This work provides a feasible reference experience for the research of plasma promoted dry reforming reaction catalysts at room temperature.

The interparticle friction behavior of saturated clay controls its mechanical properties, but remains unclear at nanoscale. As one of major clay minerals, the hydrated montmorillonite (MMT) is selected to investigate the nanoscale friction characteristics using Molecular Dynamics simulation method. Two portions of MMT representing two particles with a water film in the middle are created to simulate an undrained system. A virtual spring is applied on the upper MMT portion to provide the sliding with a constant velocity relative to the bottom portion. The effects of normal load and sliding velocity on the frictional behavior are then investigated. The friction coefficients of hydrated MMT at different cases were measured and compared with other experimental and simulation results for the validation. The evolution of normal load with the number of hydrogen bonds for hydrated MMT was finally analyzed. All simulation results indicated that the friction load fluctuated periodically with a cycle of about 9.10 A at sliding velocity inferior 0.001 A•fs−1, which was nearly equal to montmorillonite's lattice constant along the sliding direction; the fluctuation amplitude of the friction load increased with the decreasing sliding velocity; the relationship between the average friction load and the logarithm of sliding velocity followed a power function; the friction coefficient and the cohesion were found to increase approximately linearly with sliding velocity.

A multiproduct pipeline is an economical way for transporting several products from a single source to multiple delivery stations over a long distance. This paper addresses how to optimize detailed schedules of a multiproduct pipeline. A discrete-time mixed integer linear programming model is developed, which adopts a novel objective function to seek the minimum summation of pumping rate variations in every pipeline segment along a pipeline during a scheduling horizon. The feasibility of the new objective function is demonstrated in theory. A conclusion is drawn that the more stable pumping rate of a pipeline segment is, the lower frictional loss for pumping products is. Besides operational constraints, two sets of special constraints are introduced into the model for improving the operability and practicability of detailed schedules. One is the stopping and running duration limitations of injection operations and another one is the flow rate stability requirements of injection and delivery operations. The proposed MILP model is successfully tested on two real world multiproduct pipelines using CPLEX as solver.

Rational nutritional support shall be based on nutritional screening and nutritional assessment. This study is aimed to explore nutritional risk screening and its influencing factors of hospitalized patients in central urban area. It is helpful for the early detection of problems in nutritional supports, nutrition management and the implementation of intervention measures, which will contribute a lot to improving the patient's poor clinical outcome. A total of three tertiary medical institutions were enrolled in this study. From October 2015 to June 2016, 1202 hospitalized patients aged ≥18 years were enrolled in Nutrition Risk Screening 2002 (NRS2002) for nutritional risk screening, including 8 cases who refused to participate, 5 cases of same-day surgery and 5 cases of coma. A single-factor chi-square test was performed on 312 patients with nutritional risk and 872 hospitalized patients without nutritional risk. Logistic regression analysis was performed with univariate analysis (P

This paper addresses the optimization of delivery/injection plans of intermediate stations along a unidirectional multiproduct pipeline. A mixed-integer linear programming (MILP) model is developed to minimize pump rate variations in every pipeline segment along the pipeline during a specific scheduling horizon. Given the problem complexity, a computational framework is proposed consisting of three main stages: initial solution finding, solution improvement based on a simulated annealing (SA) metaheuristic, and solution refinement based on tailor-made heuristics. The algorithm for making an initial solution is based on a so-called space recursive method that the delivery/injection schedule of every intermediate station is gradually generated from upstream to downstream segments. The algorithm for generating a new solution by SA consists of three steps: selecting an intermediate station, choosing a batch passing by the selected station, and adjusting the selected operation. For improving the quality of sol...

Tumor drug resistance (TDR) invariably leads to the failure of chemotherapy. In addition, current treatment strategies for TDR are not satisfactory due to limitations in terms of safety and feasibility. The aim of the present study was to determine whether low-intensity low-frequency ultrasound (LILFU) could improve the effect of chemotherapy and reverse TDR in gemcitabine-resistant ASPC-1 (ASPC-1/GEM) cells. The investigation focused on the association between LILFU effectiveness and the adenosine triphosphate-binding cassette (ABC) transporters and the phosphoinositide 3-kinase (PI3K)/protein kinase B (AKT)/nuclear factor (NF)-κB signaling pathway. A Cell Counting Kit-8 assay was used to determine the appropriate acoustic intensity, half-maximal inhibitory concentration of gemcitabine (GEM) and the viability of ASPC-1/GEM cells. ASPC-1/GEM cells were divided into control, GEM, LILFU and GEM+LILFU groups. Cell proliferation was evaluated through colony formation assays, whereas cell apoptosis was detected using flow cytometry. Western blotting was used to explore the expression levels of ABC transporters and PI3K/AKT/NF-κB signaling pathway-associated proteins. Xenograft models in mice were established to identify the enhancing effect of GEM+LILFU in vivo. Immunohistochemistry was used to detect the expression levels of Ki-67 in tumor tissues. The acoustic parameter of 0.2 W/cm2 and a GEM concentration of 6.63 mg/ml were used in subsequent experiments. Following treatment with GEM+LILFU, the cell viability and proliferation ability were decreased, whereas the apoptotic rate was increased compared with the GEM group. The expression levels of ABC transporters, PI3K-P110α and NF-κB were decreased in the GEM+LILFU group. Notably, LILFU increased the effectiveness of GEM in inhibiting tumor growth, and reduced the expression levels of Ki-67 in the xenograft mouse model. LILFU improved the chemosensitivity of ASPC-1/GEM cells via inhibition of cell viability and proliferation, and promoted cell apoptosis in the GEM+LILFU group. In conclusion, LILFU may downregulate the expression levels of ABC transporters by inhibiting the PI3K-p110α/AKT/NF-κB signaling pathway, thereby reversing resistance in pancreatic cancer.

In recent years, perovskite solar cells have attracted the attention of many researchers due to their advantages such as high conversion efficiency, simple manufacturing process and low cost, and have become an important research direction in the field of new energy batteries. At the same time, it is also a very promising new type of solar cells. In this paper, the geometric characteristics, mechanical properties, electronic properties and optical properties of three perovskites In2TiCl6, In2TiBr6 and In2TiI6 were studied by using first-principles. The Poisson and Pugh’s ratios show the ductile characteristics of In2TiX6 (X = Cl, Br, I). The mechanical stability of studied compounds has been confirmed by the Born stability criteria. Moreover, the thermodynamic stability has been proved by the negative formation enthalpy and cohesive energy. In2TiCl6 and In2TiBr6 are indirect band gap semiconductors with band gap values 2.15 and 2.12 eV, respectively, and In2TiI6 is a direct band gap semiconductor with band gap value 1.24 eV. Theoretical calculations showed that In2TiI6 has better absorption capacity than In2TiCl6 and In2TiBr6 in the near ultraviolet and visible light regions. The results demonstrate that the compound In2TiI6 can be a potential candidate for excellent light absorbing material.

Efficient synthesis of cyclic carbonates from olefins using K2S2O8 as oxidant and NaBr as “bromination” reagent has been developed through a reaction sequence involving hydroxybromination of olefins and subsequent carboxylation of the bromohydrin in situ generated with CO2. This process provides a novel and convenient access to cyclic carbonates in a one-pot stepwise fashion. Representative olefins with different functional groups could react smoothly under relatively mild (3 MPa, 60 °C) and transition metal-free conditions to afford various cyclic carbonates.

Nanoscale mechanical behavior of kaolinite as a fundamental failure mechanism has been investigated under uniaxial tension and compression using Molecular Dynamics (MD) simulation methods. External deformation has been applied on kaolinite with a strain rate of 5 × 10−7fs−1 for tensile and compressive tests in the directions parallel (x-, y-direction)/perpendicular (z-direction) to clay mineral layers. Results showed that better mechanical performance was presented in the directions parallel to clay mineral layers than the other direction due to its continuous lattice in this plane. However, the elastic modulus of kaolinite in the z-direction was almost half of that in the other directions, which nearly equals the overall elastic modulus of kaolinite with a value of about 72.6 GPa. Compression in the x- and y-directions resulted in the separation of clay mineral layers then bending toward the octahedral sheet till crack. Compression in the z-direction resulted in slippage of clay mineral layers at the first fracture then resistance till the second fracture at the strain of about 0.2. Tension would cause cracks in the direction perpendicular to the strain direction, which may be a cleavage fracture or cracks in clay mineral sheets. Different failure modes under tension and compression were originated from the layered structure of kaolinite.

The properties of Weyl material NbAs are studied based on first principles in this paper. Firstly, the Visualizer module of Material Studio software is used to construct NbAs single-layer nanotube and nanobelt, and then CASTEP module is used to optimize and calculate the band structure, density of states and conductivity curves. The energy band, density of states and conductivity curves of carbon nanotube and nanobelt are compared. The results show that the energy band structure of NbAs has conduction band and valence band crossing at Fermi energy level, which shows obvious metallicity and is more conductive than graphene. Secondly, DMOL3 package is used to calculate and analyze the energy band and state density of NbAs nano-ribbon after adding positive and negative voltage along the armchair direction and zigzag direction, respectively. The results show that the valence band of NbAs nanobelt decreases when positive voltage is applied along the direction of the armchair, while increases when negative voltage is applied. When the voltage is applied at 0.05a.u., the peak values of the distribution curve of density of states increase from about 30 eV to 800 eV, and the peak values of the electron density of states increase significantly. When voltage is applied along the zigzag direction, either positive or negative voltage will cause the valence band to move down. When the negative voltage is −0.10a.u., the peak values of the density of states change obviously. Finally, the stability of NbAs is calculated and analyzed. It is found that NbAs nanobelt meet the requirement of stability of elastic modulus of hexagonal crystal system, but have weak shear resistance in plane (001). This indicates that the structure of NbAs is layered, similar to graphene, which is easier to be separated and detached in layers. This study can provide certain theoretical basis for our future experimental exploration of NbAs material properties.

The purpose of this paper is to examine the impact and success of a high-tech zone business incubation network project on its participants. The study aims to consider the impact of the project in terms of developing and supporting entrepreneurial activity in the East Lake of Wuhan. It seeks to establish and enhance existing technology business incubation literature and contribute to the field by identifying “good” practice and considering the measurement of success within such projects. This study employs an individual case study methodology which evaluates all aspects of the east lake high-tech zone technology business incubation network dynamically. A range of qualitative and quantitative methods are utilized to capture the views of aspiring entrepreneurs. In addition, the case study method is recognized as the most effective research strategy to capture the “rich” experience of complex project.

Deregulation of the pituitary tumor transforming gene (PTTG1), a newly discovered oncogene, is a hallmark of various malignancies, including pituitary tumors. However, the mechanisms regulating PTTG1 expression are still needed to be explored. MicroRNAs (miRNAs) are a novel class of small RNA molecules that act as posttranscriptional regulators of gene expression and can play a significant role in tumor development. Here, we identified a series of miRNAs, namely, miR-329, miR-300, miR-381 and miR-655, which could target PTTG1 messenger RNA and inhibit its expression. Interestingly, all four miRNAs significantly that are downregulated in pituitary tumors were mapped to the 14q32.31 locus, which acts as a tumor suppressor in several cancers. Functional studies show that the PTTG1-targeting miRNAs inhibit proliferation, migration and invasion but induce apoptosis in GH3 and MMQ cells. Furthermore, overexpression of a PTTG1 expression vector lacking the 3′UTR partially reverses the tumor suppressive effects of these miRNAs. Next, we identified the promoter region of PTTG1-targeting miRNAs with binding sites for p53. In our hands, p53 transcriptionally activated the expression of these miRNAs in pituitary tumor cells. Finally, we found that PTTG1 could inhibit p53 transcriptional activity to the four miRNAs. These data indicate the existence of a feedback loop between PTTG1 targeting miRNAs, PTTG1 and p53 that promotes pituitary tumorigenesis. Together, these findings suggest that these PTTG1-targeting miRNAs are important players in the regulation of pituitary tumorigenesis and that these miRNAs may serve as valuable therapeutic targets for cancer treatment.

Smart grid, as the next power grid, can efficiently monitor, predicate, and control energy generation/consumption by using the real-time users' electricity information. However, the fine-grained user energy consumption information may reveal the private information of the user. In this paper, we construct a linkable anonymous credential protocol based on Camenisch-Lysyanskaya (CL) signature. Then, we propose a privacy preserving smart metering scheme based on the new linkable anonymous credential. In addition to providing privacy protection for the user, our protocol also has the security properties of message authentication and traceability of fault smart metering. And there are some other useful features in our protocol, such as no need of trust-third party, dynamic users' enrollment and revocation, and complex statistical analysis of the energy use information. The computation cost and communication overhead of our scheme is O(1), which is independent of the user number. The simulation results show that our scheme is efficient.

Selective oxidation of sulfides was successfully performed by employing phenyliodine diacetate as an oxidant with the catalysis of TsOH in aqueous solution under mild conditions. Sulfoxides were formed with 1.1 equiv of PhI(OAc)2 at room temperature; whereas sulfones were obtained in the presence of 2.1 equiv of PhI(OAc)2 at 80 °C under otherwise identical conditions. Notably, various sulfides were converted to corresponding sulfoxides or sulfones in good to high yields by this metal-free protocol.

In order to better understand and elucidate the structural stability of perovskite materials, the lattice parameters and tolerance factors of three crystal structures of perovskite materials are ca...

Carbon dioxide, a greenhouse gas mainly from the consumption of fossil fuel, is regarded as an attractive feedstock in view of synthetic chemistry. Great efforts have been devoted to developing catalytic processes for converting CO2 into value-added compounds with reduced carbon footprint. Among versatile applications in organic synthesis, CO2 can serve as a promising raw material for fuel production, especially methanol. ‘Coming from fuel and returning to fuel’ is an appealing objective in terms of sustainable development associated with circumventing the energy shortage and CO2 issue. To date, metal complexes and organocatalysts for CO2 hydrogenation to methanol have been developed along with the reaction mechanistic insight. Understanding the interaction of active catalytic species with CO2 or hydrogen could account for development of efficient homogeneous catalysts. In this context, homogeneous catalytic hydrogenation of CO2 and its derivatives into methanol is highlighted in this article in combination with mechanistic understanding on a molecular level.

We investigate the properties of a three-dimensional (3D) dipolar Bose–Einstein condensate (BEC) in a double-well potential (DWP). The symmetry breaking and self-trapping (SBST) phenomena that the original symmetric ground state is replaced by a new asymmetric one and localized in one of the wells are demonstrated for Dy 164 atoms in the 3D DWP by means of numerical solutions of the Gross–Pitaevskii (GP) equation. The results show that the SBST properties are affected dramatically by the magnetization direction for purely dipolar BEC. The SBST under various scattering lengths are also studied. In addition, the dynamical picture of the SBST induced by a gradual transformation of the single-well potential into a double-well is also illustrated.

Establish the mechanical model of wire knot which was formed by the automatic bundling machine, and the model is simulated by ANSYS. The method can simulate testing and evaluation the strapping characteristics, thus can provide the support to design and use bundling machine properly as well as improve the strapping quality of automatic bundling machine.

In this paper, we discuss the cooperation behaviors of intelligent virtual agents with autonomous and cooperative ability .Based on the theory of fluent calculus, we have designed an agent reasoning model .In this model, intelligent virtual agent could automatically judge the next action in the action queue and constructs the dynamic environment quickly with limited information from sensor. Furthermore, a type of request/server cooperation function has been designed for the cooperation among virtual agents to solve the conflicts and to realize the joint goals. Experiment results obtained demonstrated that intelligent virtual agents could cooperate well by our reasoning model.

In order to solve the problems that diagnosis cycle is very long and diagnostic accuracy is very low dependent on the maintenance man to diagnose fault by experience, an expert system for fault diagnose of a planes airborne electronic devices based on VC++ and CLIPS is proposed. The information exchange is realized between VC++ and CLIPS through writing external function of CLIPS by VC++ platform. The fact base can be generated quickly through acquiring test parameters from test model according to the fault information template base. The expert system established by VC++ platform to write man machine interface codes and load CLIPS to realize fault reasoning can realize the fast fault diagnosis for the airborne electronic devices.

In order to solve the problems that measuring efficiency is low and measuring precision is low dependent on the maintenance man to test by manual work, a universal high precision tester of attack and slide angle sensor is proposed. The measuring efficiency has improved through the electronic spirit level that measures the attack and slide angle fast and automatically and reads data automatically. The universal property and expansibility is realized by the design method that the software and test data are designed separately. The tester in this paper is fit for the fast maintenance requirement of the attack and slide in the army, and this method has certain reference to construct other electronics tester.

A design idea of calcium tester based on embedded platform is described. The composition of calcium test system is firstly analyzed. Secondly, in the acquisition of the potential signal of solution concentration the model of a sensor system is introduced. Finally the realization technique of tester is chiefly discussed in hardware and software.