23 research outputs found

    Dynamical Analysis of Jettison Piloting for Air Bomb with Bomblets

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    The main parachutes drawn down by a pilot parachute is the generally used method of thejettison of air bomb with bomblets and their interaction process is the basis and key for thebomb projection. A mechanical model loaded by the string of pilot parachute is theoreticallyestablished, and under different projection velocities, the design method of the length and strengthfor the string of the pilot parachute is suggested. The results show that for a certain 500 kg airbomb, if the projection velocity is 222 m/s and the strength of the string is 5000 N, the lengthof the string 3 m cannot meet the requirement

    Numerical Simulation on Dispersal Character of Fuel by Central HE

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    A fuel-air explosive (FAE) device consists of a shell (top-end cover, bottom-end cover, shell-side wall), a mixed fuel, a central pipe and a burst high-explosive (HE) charged in the central pipe.The mixed fuel is filled in a column structure and dispersed by the explosion drive of central burstHE in the central pipe. The dispersed fuel mixes with air, which produces combustible cloudwhich can be detonated. That is the fuel-air explosive (FAE). The height and ignition positionof the central HE charged column affect the fuel dispersal process. The initial stage of fueldispersal was simulated by numerical computation. The simulation result indicated that thedistribution of fuel dispersal velocity, when the central HE is ignited at the end, is not the sameas that when the central HE is ignited on the axis of the central HE simultaneously. When theratio of the column height of the central HE and that of the FAE device is 0.64~0.73, the distributionof fuel dispersal velocity has little difference when the central HE is ignited at the end of column.But, when the ratio of the column height of the central HE and that of the FAE device is 0.89,the fuel axial dispersal velocity is obviously more than that when the ratio of the column heightof the central HE and that of the FAE device is 0.64~0.73

    Court Judgment Decision Support System Based on Medical Text Mining

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    Medical damage is a common problem faced by hospitals around the world and is widely watched by countries and the World Health Organization. As the number of medical damage dispute lawsuit cases rapidly grows, many countries in the world face the problem how to improve the efficiency of the judicial system under the premise of guaranteeing the quality of the trial. Therefore, in addition to reforming the system, the decision support system will effectively improve judicial decisions. This paper takes medical damage judgment documents in China as example, and proposes a court judgment decision support system (CJ-DSS) based on medical text mining and the automatic classification technology. The system can predict the trail results of the new lawsuit documents according to the previous cases verdict - rejected and non-rejected. Combined with the cases, the study in this paper found that combined feature extraction method does improve the performance of three kinds of classifiers - Support Value Machine (SVM), Artificial Neural Network (ANN) and K-Nearest Neighbor (KNN), the degree of improved performance is different from using DF-CHI combined feature extraction method. In addition, integrated learning algorithm also improves the classification performance of the overall system

    Effect of beraprost sodium on renal function and p38MAPK signaling pathway in rats with diabetic nephropathy

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    Purpose: To investigate the effect of beraprost sodium (BPS) on renal function and P38MAPK pathway in diabetic nephropathy (DN) rats.Methods: Sprague Dawley (SD) rats (n = 30) were randomly divided into three groups, viz, normal control (NC), diabetic nephropathy (DN) and beraprost sodium (BPS). Creatinine (Cr), blood urea nitrogen (BUN) and fasting blood glucose (FBG), were determined by Hitachi 7020 automatic biochemical analyzer, while low-density lipoprotein cholesterol (LDL-C), high-density lipoprotein cholesterol (HDL-C), triglycerides (TG) and total cholesterol (TC) were measured by Olympus 400 automatic biochemical analyzer. Western blot analysis was performed to examine protein expression. Interleukin-6 (IL-6), hs-CRP, and TNF-Ī± levels were evaluated using enzyme linked immunosorbent assay (ELISA).Results: After 8 weeks of treatment, renal function indices (urine output, KW/BW, UAlb/24 h, Cr and BUN), blood lipid indices (FBG, LDL-C, TG and TC) and inflammatory factors levels (IL-6, hs-CRP and TNF-Ī±) in DN group were higher than NC group (p < 0.05). In BPS group, renal function and blood lipid indices and inflammatory factor levels decreased when compared to DN group (p < 0.05). Furthermore, BPS inhibited the protein expression of p-P38MAPK, TGF-Ī²1 and COX-2.Conclusion: Beraprost sodium improves renal function in DN rats by inhibiting P38MAPK signalingpathway

    Mesenchymal stem cells as carriers and amplifiers in CRAd delivery to tumors

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    <p>Abstract</p> <p>Background</p> <p>Mesenchymal stem cells (MSCs) have been considered to be the attractive vehicles for delivering therapeutic agents toward various tumor diseases. This study was to explore the distribution pattern, kinetic delivery of adenovirus, and therapeutic efficacy of the MSC loading of E1A mutant conditionally replicative adenovirus Adv-Stat3(-) which selectively replicated and expressed high levels of anti-sense Stat3 complementary DNA in breast cancer and melanoma cells.</p> <p>Methods</p> <p>We assessed the release ability of conditionally replicative adenovirus (CRAd) from MSC using crystal violet staining, TCID<sub>50 </sub>assay, and quantitative PCR. In vitro killing competence of MSCs carrying Adv-Stat3(-) toward breast cancer and melanoma was performed using co-culture system of transwell plates. We examined tumor tropism of MSC by Prussian blue staining and immunofluorescence. In vivo killing competence of MSCs carrying Adv-Stat3(-) toward breast tumor was analyzed by comparison of tumor volumes and survival periods.</p> <p>Results</p> <p>Adv-Stat3(-) amplified in MSCs and were released 4 days after infection. MSCs carrying Adv-Stat3(-) caused viral amplification, depletion of Stat3 and its downstream proteins, and led to significant apoptosis in breast cancer and melanoma cell lines. In vivo experiments confirmed the preferential localization of MSCs in the tumor periphery 24 hours after tail vein injection, and this localization was mainly detected in the tumor parenchyma after 72 hours. Intravenous injection of MSCs carrying Adv-Stat3(-) suppressed the Stat3 pathway, down-regulated Ki67 expression, and recruited CD11b-positive cells in the local tumor, inhibiting tumor growth and increasing the survival of tumor-bearing mice.</p> <p>Conclusions</p> <p>These results indicate that MSCs migrate to the tumor site in a time-dependent manner and could be an effective platform for the targeted delivery of CRAd and the amplification of tumor killing effects.</p

    Three-dimension model of root canal morphology of primary maxillary incisors by micro-computed tomography study

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    The success of root canal treatment for deciduous teeth depends upon the shape of the root canal, among other factors. Despite this, there are limited reports on the use of high-resolution micro-CT to describe the root canal morphology of primary maxillary incisors. In this study, we aimed to create a three-dimensional (3D) digital model of the root canal morphology of primary maxillary incisors using microcomputed tomography (micro-CT). To provide a reference for the development of restorative posts for the primary maxillary incisors. Primary maxillary central and lateral incisors (nĀ =Ā 10 each) were analysed. Micro-computed tomography was used to conduct 3D analyses of the root canal system of the primary maxillary incisors. The canal volume and surface area of the primary maxillary central incisors were larger than those of the primary maxillary lateral incisors. The structural model index value was significantly lower in central incisors. At the cervical level and the interface between the cervical and middle one-third cross-sectional levels, the root canals of the primary maxillary lateral incisors were significantly rounder. The labio-palatal dimension and the diameters of the central incisors at the four different levels were significantly smaller than the diameter of the mesio-distal dimension. The taper of the central and lateral incisors gradually increased from the apical one-third to the cervical one-third in the labio-palatal dimension. The data obtained from the 3D analysis of maxillary incisors in this study will contribute to the design of root canal posts

    Metal Ions (Li, Mg, Zn, Ce) Doped into La<sub>2</sub>O<sub>3</sub> Nanorod for Boosting Catalytic Oxidative Coupling of Methane

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    A series of La2O3 nanorod catalysts with doping of active metal ions (Li, Mg, Zn and Ce) were synthesized successfully by the hydrothermal method. The La2O3 nanorods show a uniform size with the length of 50ā€“200 nm and the width of 5ā€“20 nm, and the {110} crystal facet is a preferentially exposed surface. The active metal ions (Li, Mg, Zn and Ce) doped into the lattice of La2O3 nanorods enhance the selectivity of the desired products during oxidative coupling of methane (OCM) and decrease the reaction temperature. Among these catalysts, the Mg-La2O3 catalyst exhibits the best catalytic performance during the OCM reaction, i.e., its selectivity and yield of C2 products at 780 Ā°C is 73% and 21%, respectively. The effect of doped metal ions on catalytic activity for OCM was systematically investigated. Insight into the fabrication strategy and promoting factors of the OCM reaction indicates the potential to further design a high-efficient catalyst in the future

    A Novel Grid-Forming Strategy for Self-Synchronous PMSG under Nearly 100% Renewable Electricity

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    The demand for decarbonization calls for building up a nearly 100% renewable electricity resulting in Grid-forming (GFM) capability requirements. The foregoing paradigm shifts from synchronous AC systems to converter-based systems that need to remain stable and self-synchronous while providing GFM services. However, as this articleā€™s analysis in the introduction, achieving such goals inevitably necessitates the implementation of a PLL controller and energy storage in a wind turbine, whereas it is not suitable to operate in a weak energy system. To tackle this issue, a novel grid-forming method is proposed. The suggested idea calls for creating a DC voltage controller in a grid-side converter that mimics inertia response and applying a Rotor kinetic energy storage (RKES) controller in a Generator-side converter. Moreover, a coordinated controller of RKES controllers and conventional low voltage ride-through (LVRT) is proposed to gain increases in dynamic performance and maintain grid-forming capabilities in the transient process. Extensive modeling, experimental results based on a semi-physical platform, and an actual wind farm demonstration project are provided to validate the proposed controls. The results demonstrate the effectiveness of the presented method when applied to the future 100% renewable electricity

    Enabling Manufacturable Optical Broadband Angular-Range Selective Films

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    The ability to control the propagation direction of light has long been a scientific goal. However, the fabrication of large-scale optical angular-range selective films is still a challenge. This paper presents a polymer-enabled large-scale fabrication method for broadband angular-range selective films that perform over the entire visible spectrum. Our approach involves stacking together multiple one-dimensional photonic crystals with various engineered periodicities to enlarge the bandgap across a wide spectral range based on theoretical predictions. Experimental results demonstrate that our method can achieve broadband transparency at a range of incident angles centered around normal incidence and reflectivity at larger viewing angles, doing so at large scale and low cost
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