Search

To clarify the corrosion problem of a certain gathering and transportation pipeline in the Daniudi gas field, corrosion rate tests, micro-morphology observations and corrosion product analyses were conducted on the corrosion coupons and corroded pipe sections on-site. The corrosion mechanism of the gathering pipeline in an H2S/CO2 coexistence environment was studied to provide a basis for formulating corresponding corrosion protection measures. Results showed that the average corrosion rate of the corrosion coupon was 0.092 3 mm/a, which was higher than the 0.076 0 mm/a required by the industry standard. The local corrosion rate was 0.157 0 mm/a, the pitting corrosion coefficient was 2.7, and the maximum depth of the corrosion pit on the test piece of the corroded pipe section was 88 μm. The corrosion product film had a loose structure and poor protection performance. The corrosion products mainly contained C, O and S elements, which were much higher than the chemical composition of 20 carbon steel. The corrosion products were mainly composed of FeCO3, FeS and Fe2O3, indicating that the corrosion of the gathering pipeline was mainly caused by CO2 and H2S when encountering humid environments.

The utilization of a new energy hydrogen production system is an effective approach to enhance the absorption capacity of renewable energies such as wind and solar power. The current research on energy management of electrolyzer, both domestically and internationally, primarily focuses on single-electrolyzer. The energy management of single-electrolyzer fails to account for the nonlinearity in its operational characteristics, thereby posing challenges in considering the hydrogen production efficiency of multi-electrolyzers and its impact on system economics. The present study focuses on the energy management of a novel hydrogen production system incorporating multi-electrolyzers. The energy management optimization model incorporates wind power, photovoltaic systems, batteries, and multiple electrolyzers to achieve targets for new energy consumption rate, economic income, and hydrogen production rate. Taking into account the operational characteristics of a single electrolyzer and production constraints, the multi-objective optimization problem is solved by strength Pareto evolutionary algorithm 2 (SPEA2). The simulation research demonstrates that the proposed energy management strategy can achieve a 100% absorption rate of newly generated power from renewable sources, while simultaneously increasing the hydrogen production efficiency per unit by 5.15%. The effective management of energy in a multi-electrolyzers hydrogen production system is crucial for enhancing the efficiency of hydrogen production and effectively addressing the limitations associated with single-electrolyzer operation and energy management.

To improve estimating accuracy in the traditional mean rank or median rank estimation method, an improved mean rank is proposed in the correction principle of rank estimation function as the cumulative distribution function of samples by adjusting the applicable points of natural mean rank. Then a least squares estimation is performed by directly fitting the cumulative distribution function. Based on the hypothesis of Weibull distribution under small sample, the parameter estimations under different ranks are calculated by Monte Carlo simulation. The results indicate that the relative error on calculating scale parameter using the improved mean rank method for the Weibull distribution with different parameters is less than 9.5% under the condition of sample size not less than 4. Furthermore, the relative error on calculating mean time between failures using the improved mean rank method is less than 8.7%, while the relative errors using traditional methods are higher than 16%. From calculated results, proposed method can effectively improve the parameter estimation accuracy for Weibull distribution.

To solve the problems of complex calculation and weak applicability of the traditional interval estimation methods such as Weibull distribution with the different parameters, a simple interval estimation method suitable to the conditions of multi-parameters was proposed. Through the expression of Weibull distribution, the pivotal-variable obeying chi-square distribution was obtained and the degrees of freedom were modified. Combined with the point estimation results from maximum likelihood estimation and the empirical estimation shape parameter in the Weibull distribution, the interval estimation method of two parameters in Weibull distribution was established. The confidence of proposed interval estimation method was verified by Monte Carlo simulation, and the applicability of the method on different parameters was also analyzed. Furthermore, comparisons with the results computed from traditional least square and maximum likelihood estimation methods were carried out by using simulation. Simulation results indicated that the modified pivotal-variable method has simple calculation process and small deviation from predefined nominal confidence with the different parameters. Therefore, it can be concluded that proposed method executes the more effective estimation than the traditional methods.

The traditional combination model based on multinomial logit is incapable of reflecting the nested structure of urban tourism destinations. Therefore, this paper established a variational inequality model of the combination of tourism demand distribution and transportation assignment based on nested logit. Through the first-order optimization conditions, it proved that the volume of travel distribution and transport assignment could meet the combination equilibrium conditions. Based on the MSA algorithm, it designed the solution algorithm of the model and verified the feasibility of the model and algorithm in a simplified tourism passenger transport network in Huangshan City. The calculation results show that the variational inequality model proposed in this paper can obtain the volume of travel distribution and transportation assignment at the same time, meanwhile compared with the multinomial logit, the nested logit structure fully considers the attraction measure of hotel and scenic spots, which is more in line with the choice behavior of tourists when choosing transportation route. In addition, the time value type of tourists has a great impact on the comprehensive tourism impedance which means that in the practical application, it is necessary to determine the time value type of tourists in each transportation routinereasonably.

This article delves into the synergistic integration of architectural design, structural restoration, and civil engineering, highlighting their pivotal role in fostering sustainable urban development. It explores cutting-edge methodologies and innovative practices that synergize to bolster building efficiency, fortify structural integrity, and advance environmental sustainability within urban landscapes. By delving into the latest trends in architectural design, addressing challenges and breakthroughs in structural restoration, and illuminating the evolving responsibilities of civil engineering in urban planning, this paper provides a comprehensive panorama of the intricate interplay among these disciplines. Furthermore, it ventures into the profound ramifications of technological advancements and sustainable strategies, underscoring their transformative influence on the urban environments of tomorrow. This holistic examination underscores the collective efforts of these fields in shaping resilient and eco-conscious cities poised for a sustainable future.

Education informatization has entered a new stage, and education digitalization is of great significance to promoting the high-quality development of rural education and helping rural revitalization. The research shows that the digital transformation of rural education in China is facing important problems such as the great difference in infrastructure level, the overall lack of digital application awareness and ability of rural teachers, and the mismatch between funding input and actual demand. In order to solve this series of challenges, this paper proposes a new way, by giving full play to the advantages of college students in digital technology, especially focusing on multimedia courseware production, to promote the high-quality development of rural education digitalization and provide strong support for rural revitalization.

This paper takes Hainan fishermen's Sea God belief as the research object, combines the archaeological discoveries of the South China Sea Islands, the local chronicles of Hainan Island and other documents, and the author's continuous field research data in Hainan from 2012 to 2020 and studies the Sea God belief pedigree and ritual activities of Hainan fishermen from the pedigree theory, using the methods of literature analysis and field investigation.The pedigree of the sea god family includes the sea water standard God, navigation protection God, fisherman professional (industry) God, sea god pilotage God, and others. These form the land-island-ship-spatial pedigree of immigrant societies in Southeast Asian countries; and the time pedigree of before going to sea-after returning home-before fishing-shipwreck-daily.These pedigrees have been incorporated in daily ritual activities in sea ceremonies in South China Sea Islands and daily practice. Based on the genealogical theory, the temporal and spatial genealogy of Hainan fishermen's belief and the social relations and order in ritual activities were analyzed, also by literature analysis and field investigation. The results showed that: 1) The captain has absolute authority. 2) Tradition that formed from those who first visit the island and worshiped the temple prioritized fishing. 3) Joint worship of gods is prominent, with the worship of 108 brothers being the most important and grand aspect of sacrificial ceremonies. 4) The local sea god belief of Hainan fishermen is an important symbol of identity and regional identity of overseas Chinese in Hainan.

This article deals with the degenerate fractional Kirchhoff wave equation with structural damping or strong damping. The well-posedness and the existence of global attractor in the natural energy space by virtue of the Faedo-Galerkin method and energy estimates are proved. It is worth mentioning that the results of this article cover the case of possible degeneration (or even negativity) of the stiffness coefficient. Moreover, under further suitable assumptions, the fractal dimension of the global attractor is shown to be infinite by using Z2{{\mathbb{Z}}}_{2} index theory.

Vinyl acetate, as an essential organic chemical raw material, can be used to produce polyvinyl acetate, polyester vinyl alcohol, and other products. The existing classical vinyl acetate production process has the problems of low product purity and excessive heat load. In this study, in the classical design of the process, acetylene is separated first, and then acetaldehyde is removed with the formation of an azeotrope between ethylene acetate and water. Meanwhile, considering the solubility of acetaldehyde in water and insolubility of vinyl acetate in water, the process was optimized to separate acetic acid after removing acetylene, so as to avoid the azeotrope formation of vinyl acetate and water. The nonrandom two-liquid-Hayden–O’Connell thermodynamic hybrid model was used to simulate the classical process and improved process (IP). Finally, the reflux ratio and theoretical tray number of the main separation equipment of IP were optimized to get the better parameters. The simulated results show that the purity of vinyl acetate increased from 99.1% to 99.8%, the cooling energy consumption was reduced by 16.83%, and the thermal energy consumption was reduced by 6.18%. At the same time, the equipment investment was also decreased.

Gene editing nucleases (GENs), represented by CRISPR/Cas9, have become major tools in biomedical research and offer potential cures for many human diseases. Gene editing therapy (GETx) studies in animal models targeting genes such as proprotein convertase subtilisin/kexin type 9 (PCSK9), apolipoprotein C3 (APOC3), angiopoietin Like 3 (ANGPTL3) and inducible degrader of the low-density lipoprotein receptor (IDOL) have demonstrated the benefits and advantages of GETx in managing atherosclerosis. Here we present our views on this brand new therapeutic option for cardiovascular diseases (CVD).

Background and objectiveIt has been widely reported that Early neurological improvement (ENI) after rt-PA intravenous thrombolysis contributes to a good long-term prognosis in patients experiencing acute ischemic stroke (AIS). However, which clinical factors influence after intravenous administration of recombinant tissue-type plasminogen activator (IV-rt PA) in AIS patients ENI is still unclear. This study aimed to evaluate the impact of influencing factors on the benefit of ENI after intravenous thrombolysis neurological improvement after IV-rt PA.MethodsThe data of 73 patients with acute anterior circulation ischemic stroke who received intravenous thrombolysis with rt-PA in Chongqing University Jiangjin Hospital from January 2021 to July 2022 were retrospectively studied. According to the change rate of 24 h NISHH score, the research subjects were divided into the recovery group, the significant curative effect group, the curative effect group and the no curative effect group, the ENI after intravenous thrombolysis with rt-PA was defined as the improvement rate of National Institutes of Health Stroke Scale (NIHSS)score >46% at 24 h after IV-rt PA, and univariate factor analysis was used Clinical factors associated with ENI after intravenous thrombolysis.ResultsAccording to the 24-h NIHSS improvement rate of rt-PA intravenous thrombolysis in patients with acute anterior circulation ischemic stroke, 35 cases (47.95%) of the study population had ENI. There was no statistical difference between the improvement and non-improvement group in general demographic data, stroke TOAST classification, stroke risk factors (history of stroke, heart disease, hyperlipidemia, hypertension), and laboratory test data. There was a statistically significant difference in the random blood glucose levels between the two groups (p < 0.001, t = 3.511).ConclusionThe effect of rt-PA intravenous thrombolysis within the time window of patients with acute anterior circulation ischemic stroke is significant, but the ENI after thrombolysis is easily affected by the level of blood glucose; diabetes is the most important factor affecting the acute anterior circulation ischemic stroke patients Clinical factors of ENI after intravenous thrombolysis with rt-PA.

[Objectives] The hybrid carbon-glass fiber sandwich panel structure is an effective structural form for improving the bending stiffness and strength of marine composite laminates. In order to discuss the impact damage resistance and flexible layer surface-covering protection characteristics, an experimental investigation is carried out.[Methods] The low-speed impact resistance of hybrid carbon-glass fiber sandwich panels,glass fiber laminates and hybrid carbon-glass fiber sandwich unilaterally coated rubber composite panels was compared using the drop hammer method. The analysis and further evaluation of the level of damage characteristics of the three types of panel were carried out using the first-order modal damping ratio.[Results] The results show that under the same impact energy,the damaged area of the glass fiber laminate shows a regular truncated cone shape along the thickness direction,while the damaged area of the hybrid carbon-glass fiber sandwich panel is mainly characterized by more obvious interlayer stratification concentrated on the carbon fiber;the interlayer damaged area of the glass fiber laminate is generally smaller than that of the hybrid carbon-glass fiber sandwich panel;the first-order modal damping ratio of the hybrid carbon-glass fiber sandwich panel increases with the increase of the impact energy, while the effect is lower than that of the glass fiber laminate;and the protective effect of single-sided adhesive rubber on the hybrid carbon-glass fiber sandwich panel decreases with the increase of impact energy.[Conclusions] This research on hybrid carbon-glass fiber sandwich panels can provide reliable support for their wide application in the field of ships.

Magnetic Resonance Imaging (MRI) is increasingly being used in treatment planning due to its superior soft tissue contrast, which is useful for tumor and soft tissue delineation compared to computed tomography (CT). However, MRI cannot directly provide mass density or relative stopping power (RSP) maps, which are required for calculating proton radiotherapy doses. Therefore, the integration of artificial intelligence (AI) into MRI-based treatment planning to estimate mass density and RSP directly from MRI has generated significant interest. A deep learning (DL) based framework was developed to establish a voxel-wise correlation between MR images and mass density as well as RSP. To facilitate the study, five tissue substitute phantoms were created, representing different tissues such as skin, muscle, adipose tissue, 45% hydroxyapatite (HA), and spongiosa bone. The composition of these phantoms was based on information from ICRP reports. Additionally, two animal tissue phantoms, simulating pig brain and liver, were prepared for DL training purposes. The phantom study involved the development of two DL models. The first model utilized clinical T1 and T2 MRI scans as input, while the second model incorporated zero echo time (ZTE) MRI scans. In the patient application study, two more DL models were trained: one using T1 and T2 MRI scans as input, and another model incorporating synthetic dual-energy computed tomography (sDECT) images to provide accurate bone tissue information. The DECT empirical model was used as a reference to evaluate the proposed models in both phantom and patient application studies. The DECT empirical model was selected as the reference for evaluating the proposed models in both phantom and patient application studies. In the phantom study, the DL model based on T1, and T2 MRI scans demonstrated higher accuracy in estimating mass density and RSP for skin, muscle, adipose tissue, brain, and liver. The mean absolute percentage errors (MAPE) were 0.42%, 0.14%, 0.19%, 0.78%, and 0.26% for mass density, and 0.30%, 0.11%, 0.16%, 0.61%, and 0.23% for RSP, respectively. The DL model incorporating ZTE MRI further improved the accuracy of mass density and RSP estimation for 45% HA and spongiosa bone, with MAPE values of 0.23% and 0.09% for mass density, and 0.19% and 0.07% for RSP, respectively. These results demonstrate the feasibility of using an MRI-only approach combined with DL methods for mass density and RSP estimation in proton therapy treatment planning. By employing this approach, it is possible to obtain the necessary information for proton radiotherapy directly from MRI scans, eliminating the need for additional imaging modalities.

For achieving well-performing optical thermometry, a new type of dual-mode optical thermometer is explored based on the valley-to-peak ratio (VPR) and fluorescence lifetime of Eu3+ emissions in the ZrO2:Eu3+ nanocrystals with sizes down to 10 nm. In the VPR strategy, the intensity ratio between the valley (600 nm) generated by the emission band overlap and the 606 nm peak (5D0→7F2), which is highly temperature sensitive, is employed, giving the maximum relative sensing sensitivity (Sr) of 1.8% K−1 at 293 K and good anti-interference performance. Meanwhile, the 606 nm emission exhibits a temperature-dependent decay lifetime with the highest Sr of 0.33% K−1 at 573 K, which is due to the promoted nonradiative relaxation with temperature. These results provide useful information for constructing high-performance dual-mode optical thermometers, which may further stimulate the development of photosensitive nanomaterials for frontier applications.

Hepatocellular carcinoma (HCC) is a common malignant tumor of digestive tract. Its occurrence is multistage: hepatitis-cirrhosis-precancerous lesion-HCC. The mechanism of malignant transformation from precancerous lesions to hepatocellular carcinoma is not completely clear, which may be affected by the polarization direction of Kupper cells. Kupffer cells are special monocyte macrophages in the liver. They can differentiate into M1 and M2 phenotypes in different microenvironments. They have different functions and play a role in inhibiting or promoting cancer in hepatocellular carcinoma. Studies have found that a variety of miRNAs and LncRNAs can target Kupffer polarization-related proteins to regulate their polarization direction, thereby affecting the occurrence, development and malignant transformation of precancerous lesions of the liver and reducing the incidence of liver cancer. This article mainly elaborates the frontier progress of the above researches, and provides a reference for the prevention and treatment of hepatocellular carcinoma.

BackgroundHelium-xenon gas cooled nuclear reactor adopts helium-xenon gas as the coolant and is able to apply the integral Brayton cycle. It has advantages in miniaturization and lightweight design, which has attracted more and more attention worldwide. But rare severe accidents studies have been carried out for the small helium-xenon gas cooled reactor. Probabilistic safety assessment (PSA) is an important method to evaluate the safety of a reactor system. The results obtained by PSA can provide a valuable basis for improving the core design, identifying fault, guiding operation, etc. whilst the occurrence frequency of initial events is required for PSA analysis.PurposeThis paper aims to evaluate the accident occurrence frequency for the small helium-xenon gas cooled reactor to provide an input for PSA analysis.MethodsBased on the main technical characteristics of a small innovation helium-xenon cooled mobile nuclear power system (SIMONS), the occurrence frequency of typical accidents was analyzed by referring to the operational experiences and data of high temperature gas cooled reactor (HTGR) and light water reactor (LWR). Intensity analyses were performed on the frequency of accidents such as increase or decrease of core heat removal, abnormal reactivity and power distribution, pipe break and abnormal equipment leakage, anticipated transient without scram (ATWS), and loss of offsite power (LOOP).ResultsThe calculation results show that the accidents of heat removal increase and decrease, abnormal reactivity and power distribution, pipe break and abnormal equipment leakage, ATWS, and LOOP have an occurrence frequency of 3.90×10-2 RY-1, 2.36×10-1 RY-1, 2.69×10-2 RY-1, 6.50×10-2 RY-1, 2.69×10-2 RY-1 and 4.60×10-2 RY-1, respectively.ConclusionsThe calculated results can be taken as the inputs for the PSA study of the SIMONS, providing basic reference value for further PSA analysis of mobile nuclear power system.

Objective To investigate the value of quantitative and semi-quantitative parameters of dynamic contrast enhanced magnetic resonance imaging (DCE-MRI) in evaluation of the extramural venous invasion (EMVI) in rectal cancer. Methods A total of 76 patients with rectal cancer who underwent preoperative DCE-MRI examination and total mesorectal excision in our hospital from November 2016 to June 2018 were enrolled, and the results of the examination was collected and analyzed retrospectively. The entire tumor regions of interest (ROIs) for rectal cancer was drawn, and the quantitative [volume transfer constant (Ktrans), rate constant (Kep), volume fraction of extravascular extracellular space (Ve), and volume fraction of plasma (Vp)] and semi-quantitative parameters [initial area under curve (iAUC), time to peak (TTP), Max Slope, and Max Conc] of DCE-MRI were extracted using a third-party post-processing software, Omni Kinetic (OK). Each of the parameters between the EMVI positive and the negative groups was compared to analyze their respective diagnostic efficacy, and the correlation between each parameter and EMVI was analyzed. Results The intraclass correlation coefficient for each parameter extracted by 2 physicians was excellent in this study. The Ktrans and Ve values were significantly higher in the EMVI positive group than the negative group (P < 0.05), while the Kep and Vp values and the values of all semi-quantitative parameters showed no statistical differences between the 2 groups (P>0.05). The Ktrans (r=0.353, P=0.002) and Ve (r=0.417, P < 0.001) values were positively correlated with EMVI, respectively. When the Ktrans value is larger than 0.870 or Ve value than 0.556, good diagnostic performance was obtained in identifying EMVI with the area under the curves (AUC) of 0.728 and 0.769, respectively, and Ktrans had a higher specificity (90.9%) in excluding EMVI. But, the combined application of the 2 parameters had no effect on improvement of diagnostic performance (AUC=0.779). Conclusion DCE-MRI quantitative parameters Ktrans and Ve values have important application value in preoperative evaluation of rectal cancer EMVI.

Food 3D printing as a new technology has been widely used in recent years. Base on the forming characteristics of 3D printing of fluidized food, the design scheme of the equipment was constructed by using the modular design idea. The 3D model of the equipment was first established in PRO/E. Then, the model was imported into ANSYS Workbench to carry out the finite element Static analysis and modal analysis. Static analysis results show that the maximum stress is less than the allowable stress and the strength meet the requirements. After that the first six modes of the modal analysis of the equipment was extracted and the food 3D printing experiment platform was built on the basis of the simulation. Moreover, the dynamic characteristics experiment of the food printing equipment as well as the discharge experiment were carried out. By comparing the dynamic characteristics experiment results with the simulation results, the validity of the finite element analysis was verified and the accuracy of the discharge port is up to the corresponding standard, which indicates that the designed 3D printing equipment meets the requirements.

In order to further increase the speed of tag identification, for solving the insensitivity of the frame adjustment in dynamic frame slot aloha algorithm and the high computing complexity of the Q value adjustment in Q algorithm, a new anti-collision algorithm, called continuous slot detection(CSD), is proposed. The idea of algorithm and the process of operation are introduced. In this algorithm, the optimal efficient is obtained by detecting the status of consecutive slots in frame and setting frame length by rules. The simulation results show that compared with other anti-collision algorithm, the proposed algorithm can decrease identification delay by 4% and increase identification speed by 6%.

The fretting wear behavior of micro-arc oxidation (MAO) treated ZK60 magnesium alloy under simulated bone plate-screw service condition was investigated. The MAO treatments on the surface of ZK60 magnesium alloy were conducted with different duty cycles of 20%, 30%, and 40%, respectively. Results show that the surface hardness and corrosion resistance of MAO-treated magnesium alloy specimens with different duty cycles are similar and are improved significantly in comparison with the bare magnesium alloy. Under the simulated bone plate-screw fretting condition, the worn surface of the bare magnesium alloy is characterized by ploughs and corrosion pits, accompanied with a high wear volume of 13.1×106μm3, while the wear is obviously decreased and mainly dominated by ploughs on the surface of the MAO-treated magnesium alloy. With the increase of duty cycle, the wear volume is 6.6×106,6.1×106μm3 and 6.5×106μm3, respectively. There is no obvious difference in the fretting wear behavior and the worn surface morphology among the MAO-treated ZK60 magnesium alloy specimens with different duty cycles. In sum, the anti-fretting wear performance of ZK60 magnesium alloy can be improved obviously after micro-arc oxidation treatment, and the duty cycle has little influence on the microstructure and fretting wear properties of the MAO layer on ZK60 magnesium alloy under the given experimental conditions.

Population size is a critical indicator used to assess the demographic profile and conservation status of animal species living in disturbed habitats. Using GIS technology, we calculated the remaining habitat area and estimated the population size of the Guizhou snub-nosed monkey (Rhinopithecus brelichi), an Endangered primate endemic to China. The last remaining population of this species resides in the Fanjingshan National Nature Reserve (FNNR). We combined data on forest cover and patterns of group movement to estimate the size and continuity of their habitat. The results indicated that the area of remaining suitable habitat is 69.6 km2. However the monkeys are confined to an area of only 27.8 km2 (6.6% of the total reserve area of 419 km2) located in the northern part of the reserve. The remaining 28.5 km2 of suitable habitat is located in the southern part of the reserve and inaccessible to the monkeys because of the recent construction of an aerial tram. Based on estimates of population density, we calculated that the remaining world’s population of R. brelichi is approximately 125–336 individuals. In order to protect this species from extinction, we recommend that the highly fragmented evergreen and deciduous broadleaf mixed forest adjacent to the remaining troop’s home range be given protected status and an active program of forest regeneration in this area be implemented immediately.

The characteristics of fracture development are complex in Shunbei area. The natural fracture development is different between different fault zones and in different locations of the same fault zone. Not all natural fractures can be activated during acid fracturing, and not all natural fractures can contribute to well productivity after acid fracturing. The use of natural fractures can not only improve the seepage capacity of the reservoir, but also improve the well productivity. Therefore, the influence of artificial fracture on the opening and fracture conductivity maintenance of natural fracture is studied, and finally the acid fracturing roceand parameters based on the change of natural fracture are formed.

Halophytes are plants that exhibit high salt tolerance, allowing them to survive and thrive under extremely saline conditions. The study of halophytes advances our understanding about the important adaptations that are required for survival in high salinity conditions, including secretion of salt through the salt glands, regulation of cellular ion homeostasis and osmotic pressure, detoxification of reactive oxygen species, and alterations in membrane composition. To explore the mechanisms that contribute to tolerance to salt stress, salt-responsive genes have been isolated from halophytes and expressed in non-salt tolerant plants using targeted transgenic technologies. In this review, we discuss the mechanisms that underpin salt tolerance in different halophytes.

Air-to-air missile launcher which gives missile good separation attitude and ensures launch safety is an important part in aircraft weapon system, while it has a direct impact on combat capabilities of fighters. Firstly, the development process and present status of air-to-air missile launcher are summarized, and the theoretical research hot-spots of the current mainstream launch mode of air-to-air missile such as guide rail, store ejection and embedded ejection are analyzed. It is pointed out that the high mach number launching, high overload launching, rolling launching, multidisciplinary coupling research of launching, ground ejection experiment technology considering pneumatic are still in initial stages, and they are the focal point of theoretical research in the future. Then the two present classical embedded ejection launchers of stealth fighter are compared, and the key technology, technology advantages and disadvantages of them are analyzed. Finally, the technology development directions of air-to-air missile launcher are pointed out.

To fulfill the requirements of the dielectric property measurement in the terahertz band, herein, a broadband quasi-optical system was designed and verified utilizing a planar scanning system. Additionally, the method of retrieving the dielectric parameters was discussed. Our experimental findings indicated that the measurement results were in good agreement with the theoretical results. Boron silicon, and deionized water were used for verifying the measurement, and the permittivity was obtained using a numerical method. We found that the dielectric properties were in good agreement with the typical values. This indicated that the proposed quasi-optical method effectively characterized the permittivity.

Ionic liquids-based aqueous two-phase extraction (ILs-ATPE) offers an alternative approach to the extraction of tetracycline (TC) through their partitioning between two phases. Single-stage and multi-stage strategies have been evaluated and compared for the purification of TC using ATPE composed of 1-butyl-3-methylimidazolium halide ([Bmim]X(X=Cl,Br)) and K2HPO4. The influence factors on single-stage extraction behavior of TC were optimized systematically, including the pH value, tie line length, and volume ratio. The optimal extraction efficiency of TC could reach above 95% when the volume ratio is higher than 1.5 and the tie line length is 30.52%. The multi-stage ATPE was also investigated by simulating a three-stage crosscurrent operation in test tubes. According to the TC isotherm curve and respective McCabe–Thiele diagrams, a predicted optimized scheme of the countercurrent multi-stage ATPE was determined. TC can be purified in the IL-rich top phase with a final extraction efficiency of 99% and a final TC concentration of 0.25 mg/mL, if a three- -stage [Bmim]Cl-K2HPO4 ATPE with volume ratio of 0.5 and tie line length of 30.52% was employed. Thus, the multi-stage extraction with small volume ratio is necessary to achieve a higher recovery yield, resulting in the reduction of the IL consumption.

To study the thermal aging of nuclear primary pipe material 316LN stainless steel weld, accelerated thermal aging experiment was performed at 400℃ for 15000h. Microstructure evolution of weld after aging was investigated by TEM and HREM. Impact properties of weld thermally aged at different time was measured by Charpy impact test. Meanwhile, taking Charpy impact energy as the standard of thermal aging embrittlement, the thermal kinetics formula was obtained by the fitting method. Finally, the Charpy impact properties of the weld during 60 years of service at the actual operation temperature were estimated by the thermal kinetics formula. The results indicate that the spinodal decomposition occurs in the ferrite of the weld after thermal aging at 400℃ for 1000h, results in α (Fe-rich) and α'(Cr-rich) phases, and meanwhile, the G-phase is precipitated in the ferrite; the spinodal decomposition and the G-phase precipitation lead to the decrease in the impact energy of weld as time prolongs; the prediction results show that the Charpy impact energy of weld decreases quickly in the early 25 years, and then undergoes a slow decrease during the subsequent operation process.

Recent research progresses on tissue culture (e.g. fast reproduction, another culture, protoplast culture and organogenesis) and genetic transformation of kenaf were reviewed and summarized in this paper. Existing problems were discussed, aiming to provide scientific references for promoting tissue culture and genetic transformation of kenaf.

In this paper, the size- and shape-dependent spectral characteristics of plasmonic nanostructures based on the Thue-Morse (ThMo) sequence are investigated in theory and experiment. We designed, fabricated, and characterized nine different Au nanopillars (NPs) lattices to evaluate their use as nanosensors based on localized surface plasmon resonances (LSPR). The extinction spectra and the bulk refractive index sensitivity (m) are compared to three selected shapes of the NPs (square, circular, and triangular) with different minimum interparticle distance. The maximum m of 275 nm/RIU is obtained for a ThMo pattern with square NPs. Finally, a detection limit of 260 pM (62 pg/ml) of Thiram pesticide has been achieved using an LSPR nanosensor based on an optimized ThMo pattern with triangular NPs employing a phase-sensitive setup to increase the figure-of-merit (FOM) of the sensor.

The cycloid magnetic gear transfers speed through the inner rotor rotation and revolution to get a higher transmission ratio and torque density. The permanent magnets were arranged by Halbach in order to improve the magnetic flux leakage and the utilization of permanent magnets,and a prototype was designed and manufactured according to the working principle. The magnetic field distribution and static torque characteristics of the cycloid permanent magnetic gear were researched by finite element simulation. Comparing with the general structure,it shows that the maximum torque density of even value can be increased by about 30% using 90° Halbach structure which has smaller fluctuations. Finally,the transmission torque of different angle were tested by experiments,the results are in accord with simulated results.

The MYB transcription factor (TF) superfamily, one of the largest gene superfamilies, regulates a variety of physiological processes in plants. Although many MYB superfamily genes have been identified in plants, the MYB TFs in Chinese jujube (Ziziphus jujuba Mill.) have not been fully identified and characterized. Additionally, the functions of these genes remain unclear. In total, we identified 171 MYB superfamily genes in jujube and divided them into five subfamilies containing 99 genes of the R2R3-MYB subfamily, 58 genes of the MYB-related subfamily, four genes of the R1R2R3-MYB subfamily, one gene of the 4R-MYB subfamily, and nine genes of the atypical MYB subfamily. The 99 R2R3-MYB genes of jujube were divided into 35 groups, C1–C35, and the 58 MYB-related genes were divided into the following groups: the R-R-type, CCA1-like, I-box-binding-like, TBP-like, CPC-like, and Chinese jujube-specific groups. ZjMYB genes in jujube were well supported by additional highly conserved motifs and exon/intron structures. Most R1 repeats of MYB-related proteins comprised the R2 repeat and had highly conserved EED and EEE residue groups in jujube. Three tandem duplicated gene pairs were found on 12 chromosomes in jujube. According to an expression analysis of 126 ZjMYB genes, MYB-related genes played important roles in jujube development and fruit-related biological processes. The total flavonoid content of jujube fruit decreased as ripening progressed. A total of 93 expressed genes were identified in the RNA-sequencing data from jujube fruit, and 56 ZjMYB members presented significant correlations with total flavonoid contents by correlation analysis. Five pairs of paralogous MYB genes within jujube were composed of nine jujube MYB genes. A total of 14 ZjMYB genes had the same homology to the MYB genes of Arabidopsis and peach, indicating that these 14 MYB genes and their orthologs probably existed before the ancestral divergence of the MYB superfamily. We used a synteny analysis of MYB genes between jujube and Arabidopsis to predict that the functions of the ZjMYBs involve flavonoid/phenylpropanoid metabolism, the light signaling pathway, auxin signal transduction, and responses to various abiotic stresses (cold, drought, and salt stresses). Additionally, we speculate that ZjMYB108 is an important TF involved in the flavonoid metabolic pathway. This comprehensive analysis of MYB superfamily genes in jujube lay a solid foundation for future comprehensive analyses of ZjMYB gene functions.

As the population continues to age, the daily lives of those with disabled lower limbs have gradually become an unavoidable social welfare problem. Based on an investigation and analysis into the daily routines of the elderly with partial disability in their lower limbs, the product design experiment is proposed to solve any mobility difficulties in the elderly with partial disability in their lower limbs to provide practical help that can ensure their independence and social contact. Based on the literature research and market comparison, According to the assessment criteria for the Instrumental Activity of Daily Living Scale (IADL), the physiological functions and user behaviors of this elderly population were investigated, and the actual needs for outdoor walking were analyzed. The idea of focusing on auxiliary tools for the elderly with lower limb disability was proposed, and a tool to aid in short-distance travel was designed for this target group to improve their IADL travel index and optimize their mobility.

With the deepening of reforms, as the closing year of the “Modern Vocational Education System Construction Plan (2014-2020)”, it has witnessed the development of vocational education. Its development trend is “only specialization” and “light basic courses”. Currently, the random forest method is very popular. This method forms a “forest” by building many decision trees, and votes on multiple trees to make decisions. This method can improve the classification accuracy of new samples effectively and it is more suitable for the research proposed. Random forest evaluation model has three functions: formative, diagnostic and summative. This paper establishes a comprehensive evaluation model for basic courses to make the evaluation more standardized, comprehensive and operability. And this evaluation system can supervise all stages of teaching.

Shale gas as a clean green energy has been rapidly developed in China. At present, the vertical production rate of shale gas in Chongqing area is low, and it is difficult to take into account the whole highquality shale segment with thickness of tens of meters only by one well pattern. In this paper, the internal rate of return (IRR) is used to calculate the impact of different costs and exploitation conditions on the development effect of two shale gas layers. The results show that shale gas development will be profitable only when the cost per well is controlled at around 70 million and production is provided at more than 100 million cubic meters. Domestic producers should further reduce the cost of shale gas development, increase the productivity of single well and maximize the benefit of domestic shale gas development by means of integrated innovation and technological optimization.