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Anion exchange membrane fuel cells promise a sustainable and ecofriendly energy conversion pathway yet suffer from insufficient performance and durability. Drawing inspiration from mussel foot adhesion proteins for the first time, we herein demonstrate catechol-modified ionomers that synergistically reinforce the membrane electrode assembly interface and triple-phase boundary inside catalyst layers. The resulting ionomers present exceptional alkaline stability with only slight ionic conductivity declines after treatment in 2 M NaOH aqueous solution at 80 °C for 2500 h. Adopting catechol-modified ionomer as both anion exchange membrane and binder achieves a single-cell performance increase of 34%, and more importantly, endows fuel cell operation at a current density of 0.4 A cm–2for over 300 h with negligible performance degradation (with a cell voltage decay rate of 0.03 mV h–1). Combining theoretical and experimental investigations, we reveal the molecular adhesion mechanism between the catechol-modified ionomer and Pt catalyst and illuminate the effect on the catalyst layer microstructure. Of fundamental interest, this bioadhesive-inspired strategy is critical to enabling knowledge-driven ionomer design and is promising for diverse membrane electrode assembly configurational applications.

With the extensive use of dialysis catheters in patients undergoing hemodialysis, superior vena cava (SVC) syndrome has gradually attracted attention in recent years. Chylothorax caused by SVC syndrome is rarely reported. In this paper, we report a case of chylothorax secondary to superior vena cava obstruction (SVCO) in a maintenance hemodialysis patient after multiple dialysis catheter placements. Relieving the SVCO through intravascular intervention could effectively treat chylothorax. In the past fourteen months, no recurrence of symptoms has been observed.

Biomimetic ion permselective membranes with ultrahigh ion permeability and selectivity represent a research frontier in ion separation, yet the successful fabrication of such membranes remains a formidable challenge. Here, we demonstrate a 4-sulfocalix[4]arene (4-SCA)-modified graphene oxide (GO) membrane that shows extraordinary performance in separating mono-from multivalent cations, as well as having reversible pH-responsiveness. The resulting 4-SCA-modified GO (SCA-GO) membrane preferentially transports potassium ions (K+) over radionuclide cations (Co2+, UO22+, La3+, Eu3+, and Th4+). The ion selectivities are an order of magnitude higher than that of the unmodified GO membrane. Theoretical calculations and experimental investigations demonstrate that the much-improved ion selectivity arises from the specific recognition between 4-SCA and radionuclide cations. The transport of multivalent radionuclides is impeded by a binding–obstructing mechanism from the host–guest interactions. Interestingly, the host–guest interactions are responsive to the protonation/deprotonation transformation of the 4-SCA. Therefore, the SCA-GO membrane mimics pH-regulated ion selective behavior found in biological ion channels. Our strategy of designing a biomimetic permselective GO membrane may allow efficient nuclear wastewater treatment and, more importantly, deepen our understanding of biomimetic ion transport mechanisms.

The uplift-restricted and slip-permitted (Referred to as “URSP”) connector is a new type of structure applied in the negative bending moment region of continuous steel–concrete composite beams. The application of the URSP connector can effectively releases the shear stress between the interface of composite beam, enhances the interface slip capacity, and then improves the crack resistance of concrete slab. In order to investigate the static and fatigue performance of the URSP connector, static and cyclic loading tests were carried out on two and six tensile specimens respectively. Through the experimental study, the following conclusions are obtained: (1) The static failure mode of the URSP connector is connector tensile yielding, the fatigue failure modes include tensile yield of connector and punching shear failure of concrete. (2) The fatigue stress amplitude played a decisive role in the fatigue life of the URSP connector, the fatigue life decreased sharply with the increase of the stress amplitude. Finally, the failure mechanism and S–N curve of URSP are obtained.

Background: In recent years, indocyanine green fluorescence lymphography has been introduced for lymphatic mapping in gastric cancer surgery. The aim of this study was to investigate the efficacy of ICGFL in lymph node dissection during minimally invasive surgery for gastric cancer. Methods: A systematic review of electronic databases including PubMed, Embase, Web of Science, the Cochrane Library, and China National Knowledge Infrastructure was performed from the inception to January 2021 for all studies comparing ICGFL with non-ICGFL in GC patients undergoing minimal access gastrectomy. The primary outcome was the total number of harvested lymph nodes. The secondary endpoints were the number of metastatic LNs, operative time, estimated blood loss, and postoperative complications. The registration number of this protocol is PROSPERO CRD42020203443. Results: A total of 13 studies including 1882 participants were included. In this meta-analysis, the use of ICGFL was associated with a higher number of harvested LNs (40.33 vs. 33.40; MD = 6.93; 95%CI: 4.28 to 9.58; P< 0.0001; I2= 86%). No significant difference was found between the ICGFL and control groups in terms of metastatic LNs (2.63 vs. 2.42; MD = 0.21; 95%CI: −0.46 to 0.87; P= 0.54; I2= 0%). In addition, the use of ICGFL could be safely performed without increasing the operative time (P= 0.49), estimated blood loss (P= 0.26) and postoperative complications (P= 0.54). Conclusion: The use of ICGFL may be a useful tool facilitating complete lymph node dissection during minimally invasive GC resection. However, more high-quality RCTs with large sample size are needed to validate this issue.

Anion exchange ionomers employed as electrode catalyst binders and anion exchange membranes are central components for anion exchange membrane fuel cells. Fast oxygen transport in the catalyst binder and high ion conductivity of the ionomer and membrane are essential while designing their molecular structure. Here, we tailor a fluorinated ionomer and elucidate the effect of fluorination on the properties of catalyst binder and membrane. The extraordinary oxygen-dissolving capacity of the fluorinated ionomer improves the local oxygen transport at the catalyst layer triple-phase boundary. Moreover, fluorination enhances the mechanical stability and chemical inertness of the ionomer membrane and promotes its self-assembly to construct well-defined microphase separated morphology by increasing chain thermodynamic immiscibility. The resulting fluorinated membrane shows 1.4–1.8-fold improvements in hydroxide conductivity and mechanical properties compared to the fluorine-free counterpart, as well as exceptional alkaline stability (over 90% hydroxide conductivity retention under 2 M aq. NaOH at 80 °C for 2000 h). Such synergistic improvements in ionomer binder and membrane significantly improve the single-cell performance (1.7 vs. 1.0 W cm−2peak power density) and durability (1.8 vs. 2.4 mV h−1voltage decline rate for 100 h).

Introduction: Scutellaria Baicalensis Georgi (SBG), a Traditional Chinese Medicine (TCM) used for the treatment of antiviral therapy, contains many flavonoids. Materials and Methods: A simple, fast and accurate -1H quantitative nuclear magnetic resonance (-1HqNMR) method was established for simultaneously determination of four flavonoids (Baicalin, Baicalein, Wogonin and Wogonoside) in SBG extract by using 3,4,5-trichloropyridine as an internal standard (IS). All the NMR determination work was performed at 308 K on an NMR sample tube inserted with a co-axial tube. The NMR sample tube was added with the sample (SBG extract and IS), the co-axial insert tube was added with D2O. Quantification of four flavonoids was carried out by calculating the relative peak area ratio of the selected proton signals from the target compounds and the IS. Results: The validated -1H-qNMR method was successfully used to determine the four flavonoids in 9 batches of SBG from different origins and the results were in good accordance with those obtained from HPLC. Conclusion: The established -1H-qNMR method could be used as a powerful tool for the quality control of SBG from different sources and had potential in the quantification of main components from other TCMs.

BACKGROUND:KRAS gene mutations are well known as a key driver of advanced non–small cell lung cancer (NSCLC). The impact of KRAS-mutant subtypes on the survival benefit from salvage chemotherapy is controversial. Here, we present a real-world study in patients across China with advanced NSCLC with KRAS mutations using a website-based patient self-report system. METHODS:We identified a total of 75 patients diagnosed with KRAS-mutant (determined by molecular sequencing) advanced NSCLC between 2014/5/9 and 2019/5/30. KRAS mutation subtypes were divided into G12C and non-G12C groups for statistical analysis. The clinicopathological characteristics and treatment survival benefit in all patients with a KRAS mutation were evaluated. Programmed death-ligand 1 (PD-L1) expression data were collected from 30 patients in the same cohort. RESULTS:In this study, 23 patients with stage IIIB NSCLC and 52 patients with stage IV NSCLC were enrolled with 58 men and 17 women; the median age was 60 years (39–84). All patients received regular chemotherapy/radiotherapy/targeted therapy/immune therapy as per the disease condition. Four main KRAS mutation subtypes were detected: G12C (33%), G12V (19%), G12A (12%), and G12D (12%). Three predominant KRAS comutations were detected: TP53-KRAS (31%), EGFR-KRAS (11%), and STK11-KRAS (8%). Compared with the KRAS non-G12C mutation subtype, patients with the KRAS G12C mutation had potentially longer progression-free survival (PFS) after first-line chemotherapy (4.7 vs.2.5 months, p < 0.05). Pemetrexed-based chemotherapy appeared to be superior to taxanes- and gemcitabine-based chemotherapies in all patients (PFS: 5.0 vs. 1.5 and 2.3 months, respectively, p > 0.05). Cox regression analysis showed that the KRAS G12C mutation and pemetrexed-based first-line chemotherapy were positive influencers for PFS after first-line (hazard ratios = 0.31 and 0.55, respectively, P < 0.05), but not second-line chemotherapies. CONCLUSION:The KRAS G12C mutation could be a predictive biomarker for better survival benefit from first-line chemotherapy in patients with advanced NSCLC and KRAS mutations. The first-line chemotherapy regimen could possibly influence the outcome in patients with KRAS mutations. Larger and prospective clinical trials are warranted to confirm our conclusions.

Open Radio Access Network (RAN) is an important architecture design shift for 5G and next generation telecommunications networks. With open RAN, mobile network operators would be able to mix and match multi-vendor RAN solutions as long as the solutions comply with open standards. O-RAN Alliance is the global leader in standardizing the open RAN architecture, where RAN Intelligent Controller (RIC) is positioned centrally as the brain of a RAN to manage and optimize the RAN operations. Open-source projects play a key role in accelerating the adoption of open RAN architecture, especially the use of RIC. However, the fast pace of development and the lack of documentation in open-source projects create steep learning curve for beginners. In this paper, we first provide an overview of widely used open-source RIC projects and discuss their pros and cons. We then share our first-hand experience to use RIC in our campus 5G network that consists of commercial-grade RAN solutions. In particular, we developed a suite of three RAN control applications (i.e., energy efficiency, interference management, and predictive maintenance) on an open-source RIC, and we deploy and evaluate them on a commercial-grade 5G network in a university campus. For these RIC applications, we design and evaluate different ML models based on real-world data collected from our 5G network, which we publish together with this paper. Our experimental results show that AI-based RIC applications can achieve more than 90% of accuracy in inferring the situation of the RAN for each given task. Our energy-saving RIC application can reduce 65% of energy consumption of the RAN over a simulated period of one year. Our project also validates the feasibility to interfacing an open-source RIC with existing commercial-grade 5G solutions.

The cracking of concrete flanges in the negative bending moment region has always constrained the development of steel-concrete composite continuous beams. The proposal of steel-concrete composite-laminated beam is one of the effective ways to solve this problem. As a new type of structure, the research on its mechanical properties is not yet sufficient. In order to study the residual mechanical properties of composite-laminated beams after cyclic load tests, static load tests were conducted on one composite-laminated beam specimen, and cyclic load and final failure static load tests were conducted on three composite-laminated beam specimens. The experimental results show that the fatigue failure mode of the composite-laminated beam was characterized by uplift-restricted and slip-permitted connectors failure, and the steel beam was still in an elastic state at this time. Compared with the static load specimen, the stiffness of the specimen that failed in the cyclic loading test decreased by about 30%, the bearing capacity decreased by about 10%, and the residual bearing capacity and ductility were basically stable, without affecting the normal operation of the specimen. Therefore, the new structure not only has good static performance, but also has good fatigue resistance.

Polymer electrolyte membrane fuel cells can generate high power densities with low local emissions of pollutants. Optimal ionomer-Pt/C catalyst interactions in the electrodes enable the efficient generation and transport of ions and electrons required for high fuel cell performances. Critical durability issues involve agglomeration of the Pt/C nanoparticles (Pt/C NPs) and ionomer during discharging. Our novel approach involves ionomer cross-linking immobilization for the fabrication of durable catalyst layers for application in alkaline anion exchange membrane fuel cells (AEMFCs). Pt/C NP catalysts are employed alongside a poly(2,6-dimethyl-p-phenylene oxide)-(PPO)-based quaternary ammonium ionomer (containing terminal styrenic side-chain groups) to form porous catalyst layers. Following thermally initiated cross-linking of the terminal vinyl groups, an interconnected ionomer network forms conductive shells around the Pt/C aggregates. Ex situ catalytic activity and in situ durability tests demonstrate that this immobilization strategy inhibits Pt/C NP coalescence without sacrificing catalyst layer porosity. An initial demonstration of an H2/O2AEMFC containing the new CBQPPO@Pt/C cathode shows that high peak power densities can be achieved (1.02 W cm–2at 70 °C, raising to 1.37 W cm–2with additional 0.1 MPa back-pressurization).

As a critical component of alkaline fuel cells, anion exchange membranes determine the energy efficiency, output power density and the long term stability. Recently, the anion exchange membranes with gemini-cation side chains exhibit superior ion conductivity due to their good nanophase separation. However, the costly and complicated synthesis limits their scaling up and commercialization. To address this problem, a convenient synthetic procedure under mild conditions is well developed. A tertiary amine precursor is introduced onto the polymer by the nucleophilic substitution reaction to avoid the conventional chloro/bromo-methylation. Followed by a simple Menshutkin reaction with 6-bromo-N,N,N-trimethylhexan-1-aminium bromide, the polymer electrolytes are obtained in a high yield. The resulting anion exchange membranes with high conductivity, good fuel cell performance and restricted swelling suggest the potential for the application in fuel cell devices. 作为碱性燃料电池的关键组分, 阴离子交换膜决定了其能量转化效率, 输出功率密度及长期稳定性. 最近, 带有双离子侧链的阴离子交换膜, 因其良好的微相分离能力, 表现出了优异的离子电导率. 然而, 昂贵且复杂的合成方法限制了其商业化应用. 为了解决这一问题, 本文开发了一种简单、温和的合成方法. 首先通过亲核取代反应将叔胺前驱体引入到聚合物主链上, 避免了常用的氯/溴甲基化反应. 随后与溴己基-N,N,N-三甲基铵进行简单的门秀金反应, 以高产率获得目标聚合物电解质. 所得到的阴离子交换膜表现出高的离子电导率, 良好的燃料电池性能以及有限的溶胀, 表明所提出的策略在燃料电池中具有应用前景.

Introduction: Quantitative NMR spectroscopy (qNMR) is a rapid, simple and efficient method for the assay of sulfasalazine (SSZ) in commercial tablet formulation. Materials and Methods: The qNMR method was demonstrated using maleic acid as an internal standard and DMSO-d6 as a solvent. The characteristic signals of SSZ at δ 8.36 ppm and maleic acid at δ 6.28 ppm were quantified. The reliability of the quantification method had been implemented successfully in validated experiments including specificity and selectivity, linearity, recovery, precision concentration rang, limit of detection (LOD), limit of quantification (LOQ), stability and robustness. Conclusion: The method was found to be liner (R2 = 0.9991) from 8.62 to 20.14 mg/0.6 mL DMSO-d6 in the drug concentration range. The maximum relative standard deviation (RSD) of recovery and precision were tested to be 0.59% and 0.65%, respectively. The LOD and LOQ were determined to be 0.02, 0.07 mg/mL, respectively. The RSD of stability was 0.05%. The robustness was demonstrated by changing four different parameters with the maximum difference less than 0.9%. In addition, the result of qNMR showed in good agreement with the HPLC and UV methods. Based on the experiments, the developed method was successfully applied to the determination of SSZ in commercial tablet.

This work aims to prepare ferulic acid alkyl esters (FAEs) through the lipase-catalyzed reaction between methyl ferulate and various fatty alcohols in deep eutectic solvents and ascertain their antibacterial activities and mechanisms. Screens of antibacterial effects of FAEs against Escherichia coliATCC 25922 (E. coli) and Listeria monocytogenesATCC 19115 (L. monocytogenes) revealed that hexyl ferulate (FAC6) exerted excellent bacteriostatic and bactericidal effects on E. coliand L. monocytogenes(minimum inhibitory concentration (MIC): 1.6 and 0.1 mM, minimum bactericidal concentration (MBC): 25.6 and 0.2 mM, respectively). The antibacterial mechanism of FAC6 against E. coliwas systematically studied to facilitate its practical use as a food additive with multifunctionalities. The growth and time-kill curves implied the partial cell lysis and inhibition of the growth of E. colicaused by FAC6. The result related to propidium iodide uptake and cell constituents’ leakage (K+, proteins, nucleotides, and β-galactosidase) implied that bacterial cytomembranes were substantially compromised by FAC6. Variations on morphology and cardiolipin microdomains and membrane hyperpolarization of cells visually verified that FAC6 induced cell elongation and destructed the cell membrane with cell wall perforation. SDS-PAGE analysis and alterations of fluorescence spectra of bacterial membrane proteins manifested that FAC6 caused significant changes in constitutions and conformation of membrane proteins. Furthermore, it also could bind to minor grooves of E. coliDNA to form complexes. Meanwhile, FAC6 exhibited antibiofilm formation activity. These findings indicated that that FAC6 has promising potential to be developed as a multifunctional food additive.

The abnormal local friction and wear phenomena usually generate during the service of the titanium alloy rotor /stator parts of the aero engine compressor under high temperature conditions. This phenomenon is the main cause of the occurrence of titanium fire failure and has great harm. In the present investigation the friction and wear behavior of the combustion resistant titanium alloy at high temperature was studied by finite element numerical simulation and experimental verification of the pin-on-disk model. Firstly, the geometrical model of the round bottom pin-on-disk contact was established. Then, the friction process was simulated by the Coulomb friction model. The ALE technique of ABAQUS was applied to move the contact nodes and update the grid. The finite element simulation of the ARCHARD wear model was realized. In order to deal with the increasing contact area, a simplify wear direction was proposed. Finally, the wear depth and volume was calculated and the wear law at 500 °C -900 °C was revealed. The results show that the wear process is gentle at the temperature of 500-700 °C, and the wear depth is within 0.08mm when the sliding distance reaches 1800m. When the temperature exceeds 800 °C, the wear rate increased sharply and the wear depth beyond 0.1mm, the FE result is consistent with the test results.

The purpose of this study was to evaluate distending the stomach with water for ultrasound detection of focal lesions in the elongated left lobe of the liver. A total of 13,277 patients undergoing liver ultrasound were evaluated for the presence of an elongated left lobe of the liver and a focal lesion. Patients with an elongated left lobe of the liver had their stomach distended with oral water for further evaluation of a focal lesion. A portion of the patients had computed tomography (CT) examinations, which were compared with the ultrasound studies. A total of 643 patients were found with elongated left lobe of the liver by ultrasound; of them, 451 underwent CT, 259 out of the 451 patients meeting the inclusion criteria underwent second ultrasound and final analysis, and 16 of these 259 patients had focal lesion in the elongated left lobe of the liver on CT study. The sonographic visualization of the liver and spleen at the same scan view before and after distending the stomach were 7% (7 of 100) and 100% (100 of 100), respectively (P< .001). The sonographic detection of the lesions before and after distending the stomach were zero and 87.5%, respectively (P< .001). Distending the stomach with water can greatly increase ultrasound detection of focal lesions in the elongated left lobe of the liver.

Schistosomiasis is a notable neglected tropical disease caused by trematodes that infect mainly the intestines, bladder, and liver. Because of the unavailability of a schistosomiasis vaccine, control of the disease depends mainly on chemotherapy. Praziquantel (PZQ), which is active against all schistosome species (Among the five major species of human schistosomes−S. mansoni, S. haematobium, S. japonicum, S. intercalatum, and S. mekongi, S. mansoni is the most prevalent) as well as probably their hybrids and the recommended drug by the World Health Organization for schistosomiasis treatment at either the community or individual level, has become the exclusive drug because of its low cost and efficacy against the adult form of all schistosome species. In view of rapid re-infection following treatment and concern about the development of tolerance and/or resistance to praziquantel, there is an urgent need for research and development of novel drugs for the prevention and treatment of schistosomiasis. This comprehensive review shall attempt to briefly review the recent advances in the synthesis of antischistosomal drugs and agents in the literature from 1990s to now, particularly focusing on the context of potential development of antischistosomal agents. It shall be of interest for the pharmacologist.

To solve the problem of traditional methods for calculating transient thermo-mechanical coupled response, which cannot accurately reflect the coupled effect between heat transfer and structural deformation without considering a wide change in temperature, a transient finite element method for solving the thermo-solid coupled effect is established based on Galerkin and Newmark algorithms. The method fully considers a wide and rapid change in temperature for solving the thermo-mechanical coupling problem. By calculating the transient thermal response of an aluminum plate with a process of strong heat flow, the correctness of the method is proved. The results for solving the thermo-mechanical coupled problem of a thermal protection panel on the inlet of a hypersonic vehicle by use of this method show that the effect of a rapid change in temperature on calculated results of the transient thermo-mechanical coupled problem is significant; the impact of the coupled term considering dramatic change in temperature on the temperature field of the structure is small, but it induces the vibration of the rate of temperature change, and the coupled term also affects the displacement and the velocity and the acceleration of deformation of the structure significantly, and plays a damping role in the structural vibration. [ABSTRACT FROM AUTHOR]

In spectral-like resolution-WENO hybrid schemes, if the switch function takes more grid points as discontinuity points, the WENO scheme is often turned on, and the numerical solutions may be too dissipative. Conversely, if the switch function takes less grid points as discontinuity points, the hybrid schemes usually are found to produce oscillatory solutions or just to be unstable. Even if the switch function takes less grid points as discontinuity points, the final hybrid scheme is inclined to be more stable, provided the spectral-like resolution scheme in the hybrid scheme has moderate shock-capturing capability. Following this idea, we propose nonlinear spectral-like schemes named weighted group velocity control (WGVC) schemes. These schemes show not only high-resolution for short waves but also moderate shock capturing capability. Then a new class of hybrid schemes is designed in which the WGVC scheme is used in smooth regions and the WENO scheme is used to capture discontinuities. These hybrid schemes show good resolution for small-scales structures and fine shock-capturing capabilities while the switch function takes less grid points as discontinuity points. The seven-order WGVC-WENO scheme has also been applied successfully to the direct numerical simulation of oblique shock wave-turbulent boundary layer interaction.

A general non-smooth trajectory optimization approach is developed in the present paper. The mesh refinement procedure based on data compress for dyadic grids is improved to increase efficiency, usability, and flexibility, and is then combined with the local collocation method which takes advantage of scaling, sparsity and numerical differentiation of NLP. Numerical examples of several challenging non-smooth trajectory optimization (including bang-bang control and so on) demonstrate that: (1) the approach solves non-smooth trajectory optimization rapidly with high accuracy, and captures non-smooth regions exactly with density mesh; (2) the approach captures non-smooth regions of states although the mesh is refined according to controls ; (3) for the local collocation method, it is better to refine the mesh rather than divide the non-smooth trajectory into multiple segments. [ABSTRACT FROM AUTHOR]

This paper reports the direct numerical simulation (DNS) for hypersonic turbulent boundary layer over a flat-plate at Ma∞=8 with the ratio of wall-to-freestream temperature equal to 1.9, which indicates an extremely cold wall condition. It is primarily used to assess the wall temperature effects on the mean velocity profile, Walz equation, turbulent intensity, strong Reynolds analogy (SRA), and compressibility. The present high Mach number with cold wall condition induces strong compressibility effects. As a result, the Morkovin’s hypothesis is not fully valid and so the classical SRA is also not fully consistent. However, some modified SRA is still valid at the far-wall region. It is also verified that the semi-local wall coordinate y* is better than conventional y+in analysis of statistics features in turbulent boundary layer (TBL) in hypersonic flow.

Because of its advantage of zero casualties, Unmanned Aerial Vehicle (UAV) plays an important role in battlefield monitoring and information acquiring, thus caught great attention of the world. But with large quantities of UAVs equipped, uncertain life-span has become an important constraint of operating UAV safely and economically. So assessing the service life has important military and economic values. In the entire UAV system, the airframe life severely affects operation of UAV. According to method of damage coefficient, evaluation model on life of UAV airframe was established. In the case of security, its fatigue life was determined.

A simple, convenient and highly efficient aerobic oxidative trimerization of indoles has been developed using TEMPO in air, and the corresponding 3-(1H-indol-3-yl)-3,3-biindolin-2- one derivatives were obtained in moderate to excellent yields. This methodology provides an alternative approach for the direct generation of all-carbon quaternary centers at the C3 position of indoles.

Parachute recovery of UAV is often caused of holes and other injuries on wings, that are required repair and maintenance. The surface of the patch will form the high stress area, that affects UAV using life and safety .But repair method is good or bad directly affects size of the high stress area. Based on finite element method, the broken hole repairing method was formulated and validated by ANSYS. The method could minimize the high stress area as far as possible, and economically repair broken hole of wing in certain precision and safety standards condition. It has a certain reference value for UAV repair and management, and has reference significance for extending the service life of the UAV. Key words: Finite element method; Unmanned Aerial Vehicle (UAV); Simulation; Hole of wings

The quality of highway roadbed construction which affects the overall performance of highway is the most important to the highway construction. The roadbed is the crucial part of highway engineering. Its stability directly restricts the process of the highway roadbed construction, quality and the engineering costs, and relates to the security of people's lives and property, and to the regional economic development. And the roadbed soft foundation treatment is the key to construction of subgrade, usually by apply pad chemical fiber non-woven fabrics, geotextile, glass fiber grating way to deal with soft foundation. This article is to analyze the monitoring data of the highway roadbed engineering and to study the process and means of highway roadbed monitoring[1]. Actually, it helps and guides us to deal with the highway’s soft foundation significantly.

The inverse design of air-to-air missile system was researched according to its target performance database. Firstly the initial model and database of air-to-air missile were set based on a foregone and similar missile model which includes the database of aerodynamic coefficients, engine performance, mass properties, guidance law and so on. Then this initial model and database were optimally modified by using the improved elitist preserved genetic algorithm and flight simulation based on the 4-D motion differential equations of both the air-to-air missile and target vehicle. The inverse design algorithm globally minimized the performance errors which were obtained from the inversely designed envelopes compared with the desired target performance database of maximum intercept envelope and the maximum impossible escape (no-escape) envelope. The optimized numerical simulation results of inverse design are showing that both the average error and the maximum error of missile envelopes are very small and can be acceptable, which verified that the inverse design algorithm of system is high accuracy and reliable.

Purpose This study attempted to observe the effect of feeding regulation measures (FRM) for the construction of an esophageal channel function in a neoesophagus using an artificial nitinol esophagus.Methods Experiments were divided among groups: group 1, receiving FRM; and group 2, the non-feeding regulation measures (NFRM) group.Results Ten pigs survived for 6 months without any complications such as anastomotic leakage. The shedding time of the artificial esophagus in group 1 was significantly delayed in comparison with group 2 (>180 ± 0.0 days vs. 75.6 ± 27.1 days, respectively, p<0.05). In group 1, the weight changes at 3 and 6 months postoperation were significantly different in comparison with preoperative values (t = 14.86, 9.17 > 2.78, respectively; p<0.05). In group 2, the weight changes at 3 and 6 months postoperation were significantly different in comparison with preoperative values (t = 7.95, 11.37 > 2.78, respectively; p<0.05).Conclusions FRM not only effectively delayed the shedding time of the artificial esophagus but also played a role in protecting the neoesophagus from stenosis, by functioned as a bougienage after artificial esophagus sloughing. Therefore, FRM is an effective way for establishing a stable eating channel in the neoesophagus when using a nitinol composite artificial esophagus to replace the resected segment of an intrathoracic esophagus.

The Cr1-xAlxN coatings were deposited onto M2 tool steel using ion arc plating technique. The effect of current density on the surface morphology and mechanical properties of TiN/CrAlN coating was made. It was found that adjusting the pure metal target currents is not only to change the metal atomic ratio, but also to influence the surface morphology, their hardness and adhesion. The micro hardness Hv increases almost linearly with Al content of the coating in this study, and the Cr0.41Al0.59N coating reaches Hv 2950. The adhesion force between the coating and the substrate reaches maximum value 55N, when the [Al]/[Al+Cr] ratio is 0.44.

Using cation amino polysiloxane emulsion(ASE) and anion carboxyl polysiloxane emulsion (CSE) as materials, mixing ASE and CSE together to self-assemble or aggregate by electrostatic interaction, supramolecular compound emulsion (ASE-CSE) was formed. TEM and particle size analyzer observation showed that the particle of ASE-CSE is sphericity, and its particle diameter is bigger than that of mono-composition emulsion and has single-peak distribution. SEM, atomic force microscope (AFM) and other instruments detections indicated that the ASE-CSE possesses good form-film property. The ASE-CSE film on the silicon wafer is very rough. There are many islands or peaks package on the film surface. The average thickness of the film is 12.45nm, and it is about 7.1 times as against ASE. With the ASE-CSE film, the stripes or grooves on the fiber surface is weakened or disappeared. And the surface is smoother than that of the control sample. In addition, the contact angle of the cotton fabric treated by ASE-CSE is 86.5°. This reveals that the ASE-CSE film brings fiber fabric from hydrophile to hydrophobe.

The floating of floor due to insufficient anti-floating of floor happens occasionally in the design and construction process of basement parking garages. In this paper, the causes of insufficient anti-floating of basement parking garage floor are analyzed combined with engineering examples.

The competition and symbiosis relation of minor enterprises results from their active participation and other factors. The main motivations of their symbiotic development are to integrate different resources of relavant enterprises, share benefits and risks, promote continuely rapid development. In network economy era, cooperative symbiosis is playing an important parts in enterprise strategic management and innovation.

A novel kind of diamond-TiC-Ti gradient interlayer has been successfully obtained between self-standing diamond and Ag/Cu films by combining Ti ion implanted into the achieved CVD diamond films by MEVVA with depositing Ti layer and by magnetron sputtering and annealing in vacuum. In the metallization system, RF sputtering was also utilized to deposit Ag/Cu films consistent with target composition based on orthogonal experimental design. Transition from Ti to Ag/Cu could be controlled to distribute gradually through adjusting both of their deposition powers. X-ray photoelectron spectroscopy (XPS) and X-ray diffraction (XRD) results show TiC is formed and the content of Ti increases gradually in diamond and decreases in the sputtering depth profiles of the Ti-Ag/Cu film. Raman spectroscopy indicates the effects of Ti ion implantation on the structure of diamond. Gradient design leads to order-of-magnitude improvements in adhesion between diamond and Ag/Cu films, which can be a good choice for heat sink.

Inventory checking is one of the most significant parts for grain reserves, and plays a very important role on the macro-control of food and food security. Simple, fast and accurate method to obtain internal structure information and further to estimate the volume of the grain storage is needed. Here in our developed system, a special designed multi-site laser scanning system is used to acquire the range data clouds of the internal structure of the grain storage. However, due to the seriously uneven distribution of the range data, this data should firstly be preprocessed by an adaptive re-sampling method to reduce the data redundancy as well as noise. Then the range data is segmented and useful features, such as plane and cylinder information, are extracted. With these features a coarse registration between all of these single-site range data is done, and then an Iterative Closest Point (ICP) algorithm is carried out to achieve fine registration. Taking advantage of the structure of the grain storage being well defined and the types of them are limited, a fast automatic registration method based on the priori model is proposed to register the multi-sites range data more efficiently. Then after the integration of the multi-sites range data, the grain surface is finally reconstructed by a delaunay based algorithm and the grain volume is estimated by a numerical integration method. This proposed new method has been applied to two common types of grain storage, and experimental results shown this method is more effective and accurate, and it can also avoids the cumulative effect of errors when registering the overlapped area pair-wisely.

A novel polysiloxane bearing (N,N)-dimethyl-γ-aminopropyl-γ-aminopropyl side groups(ASO-2) was synthesized by copolymerization of octamethylcyclotetrasiloxane with (N,N)-dimethyl-γ-aminopropyl-γ-aminopropyl methyl dimethoxysilane and hexamethyldisiloxane. Chemical structure, film morphology and the softening fabric property of ASO-2 were characterized and investigated by IR, 1H-NMR, SEM, atomic force microscope(AFM) and Kawabata evaluation system(KES).The experiment results indicate that ASO-2 can form a hydrophobic film on both the cotton fiber and silicon wafer surface. The ASO-2 film relatively exhibits a non-homogeneous structure and uneven morphology in its AFM images. Consequently, in 2 μm2 scanning field, the root mean square roughness of ASO-2 film reaches to 0.226 nm, which is 2.69 times rougher as compared with that of N-β-aminoethyl-γ-aminopropyl polysiloxane (ASO-1) film. Application experiments indicate though the tactile of ASO-2 imparted on 100% cotton is somewhat rougher than that of ASO-1, the whiteness and wettability of the cotton treated by ASO-2 are better than those by ASO-1.

With Chinese automobile industry in its infancy, the model of its development will play a leading role to remain invincible in an increasingly competitive market. Based on the status analysis of automobile manufacturing development, this paper adopts the fundamental principles of symbiosis theory to dissect the symbiotic relationship between Chinese automobile manufacturing enterprises and small and medium-sized supporting enterprises and demonstrate its symbiotic form in detail, referred to enterprise network, and thus put forward the symbiotic mode suited for Chinese automobile manufacturing enterprises and small and medium-sized supporting enterprises.

In this paper, the TiN/TiAlN duplex coatings were deposited on SKH51 tool steel by means of multi-arc ion plating. By means of SEM, Vickers microhardness tester and scratch tester, the effect of target current levels on the surface morphology and mechanical properties of TiN/TiAlN duplex coatings on SKH51 tool steel was studied. During deposition, the effect of target current on microstructure and mechanical properties is responsible for the number, energy of emission target particles and distribution of target droplets. It was found that the thickness and microhardness of coatings, and the number of droplets with diameter more than 2 m increased with target current increasing. The adhesion force between coating and substrate reaches a peak value of 40.5N at 70A. From application view, it is better to control the Ti-Al target current density at 9.88x10-3 A/mm2.

Abstract: A direct numerical simulation of the shock/turbulent boundary layer interaction flow in a supersonic 24-degree compression ramp is conducted with the free stream Mach number 2.9. The blow-and-suction disturbance in the upstream wall boundary is used to trigger the transition. Both the mean wall pressure and the velocity profiles agree with those of the experimental data, which validates the simulation. The turbulent kinetic energy budget in the separation region is analyzed. Results show that the turbulent production term increases fast in the separation region, while the turbulent dissipation term reaches its peak in the near-wall region. The turbulent transport term contributes to the balance of the turbulent conduction and turbulent dissipation. Based on the analysis of instantaneous pressure in the downstream region of the mean shock and that in the separation bubble, the authors suggest that the low frequency oscillation of the shock is not caused by the upstream turbulent disturbance, but rather the instability of separation bubble.

Iron catalysts are extensively used in organic reactions in recent years since iron is one of the most abundant metals on earth, consequently one of the most inexpensive, and environmentally friendly ones, and many iron salts and complexes are commercially available. This comprehensive review attempts to cover the advances of iron-catalyzed organic reactions in the literature from 2007 to Sept 2009, particularly focusing on the formation of carbon-carbon bond. Simultaneously, the iron-catalyzed formation of carbon- heteroatom and heteroatom- heteroatom bond also are commented briefly.

Abstract: Effects of wall temperature on stabilities of hypersonic boundary layer over a 7° half-cone-angle blunt cone are studied by using both direct numerical simulation (DNS) and linear stability theory (LST) analysis. Four isothermal wall cases with , as well as an adiabatic wall case are considered. Results of both DNS and LST indicate that wall temperature has significant effects on the growth of disturbance waves. Cooling the surface accelerates unstable Mack II mode waves and decelerates the first mode (Tollmien–Schlichting mode) waves. LST results show that growth rate of the most unstable Mack II mode waves for the cases of cold wall are about 45% and 25% larger than that for the adiabatic wall, respectively. Numerical results show that surface cooling modifies the profiles of and temperature in the boundary layers, and thus changes the stability characteristic of the boundary layers, and then effects on the growth of unstable waves. The results of DNS indicate that the disturbances with the frequency range from about 119.4 to 179.1kHz, including the most unstable Mack modes, produce strong mode competition in the downstream region from about 11 to 100 nose radii. And adiabatic wall enhances the amplitudes of disturbance according to the results of DNS, although the LST indicates that the growth rate of the disturbance of cold wall is larger. That because the growth of the disturbance does not only depend on the development of the second unstable mode. [Copyright &y& Elsevier]

In a previous study, we replaced a thoracic esophagus with nitinol composite artificial esophagus. Two major problems of anastomotic leakage and early sloughing of the grafted prostheses were noted. We have developed a new type of nitinol composite artificial esophagus with polyester connecting ring, and in this study, we test the effectiveness of replacing a thoracic esophagus with this new type of tube. We experimented with two groups: with polyester connecting ring (experimental) and without (control). The shedding time of artificial esophagus in the experimental group was significantly delayed compared with the control group (127.2 ± 51.8 days vs. 27.6 ± 15.7 days, respectively, p< 0.05). The incidence of the two major postoperative complications in the experimental group was significantly decreased compared with the control group: anastomotic leakage (0% vs.33.3%, respectively, p< 0.05) and severe neoesophageal stenosis after prostheses sloughing (10% vs.50%, respectively, p< 0.05). The long-term survival rate (>6 months) in the experimental group was significantly increased compared with the control group (100% vs.10%, respectively, p< 0.05). These results suggest that the polyester connecting ring improves outcome of replacement of the thoracic esophagus with nitinol composite artificial esophagus.

Framed curing mold is subjected to an uneven thermal load, gravity force and the pressures from composite parts and auxiliary tools during autoclave processing of thermosetting composite structures. And those loads induce the warpage of framed-mold. The warpage of framed-mold during autoclave processing influences dimensional precision of composite parts. In the present work, a three-dimensional finite element model for prediction of the warpage of framed-mold during autoclave processing has been developed. This model solved the coupling problem between the deformation and the temperature distribution of framed-mold and allows analysis of all major identified deformation influencing factors. And numerical predictions compare quite well with experimental measurements. A parametric study was performed using FEM program to examine the effect of varying the thickness of framed-mold, the shape and the dimension of mold vents.

Quantity production of low-cost and high-performance proton exchange membranes (PEMs) used in hydrogen fuel cells is the centerpiece step toward the hydrogen future. Herein, we developed a facile synthesis approach for this task. The prepared PEM breaks through the unfavorable trade-off between thermal-dimensional stability and proton conductivity due to the adequately designed hierarchical polymer structure composed of flexible ionic side-chains anchored onto twisted rigid backbone. Microscale topology structure analyses and molecular dynamics simulations indicate that the hydrated ionic groups self-assemble to form well-connected proton nanochannels. More importantly, the quantity production of the PEM is allowed with a pilot-scale production line. The PEM reaches a peak power density of 1.2 W cm–2under the realistic low fuel gas flow in a single-cell of H2/O2fuel cell. Additionally, the PEM maintains profitable fuel cell performance under lower relative humidity (1.1 and 0.9 W cm–2peak power density at 80 and 60% relative humidity, respectively). In short, we report that a canonical form from the structural optimization of a PEM to the pilot-scale production in which the micromorphology-proton conduction relationship is fully explored.

An analytical HPLC method using CHIREX (S)‐LEU/(S)‐α‐NEA column was developed for the determination of the enantiomeric excesses of N‐protected (S)‐3‐hydroxyglutarimides. Using this method, detailed studies on the base‐promoted ring‐expansion reaction of the amidolactones, derived from l‐glutamic acid, were undertaken. © 2005 Wiley‐Liss, Inc. Chirality 17:595–599, 2005.

The preliminary design of a Ka-band, second harmonic, three cavities gyroklystron amplifier is presented. The beam-wave interaction in the second harmonic gyroklystron amplifier is studied by using a particle-in-cell code, and the validity of the design of the microwave circuit is also discussed. The results show that this gyroklystron can produce an output peak power of over 200kW with 20dB gain and 20% maximum efficiency at 35GHz.