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In the co-curing process of aramid honeycomb sandwich structures with traditional hexagonal core lattice structures，the deformation compatibility of honeycomb with locally varying structures outside the plane is an important factor affecting the internal forming quality of sandwich structures. This article analyzes the out-of-plane local deformation performance of honeycombs using numerical methods by establishing a finite element quantitative analysis model，combining typical structural experimental verification methods，using full-body modeling and elastic mechanics plate bending theory. It explores the influence of key factors such as honeycomb thickness and external pressure on honeycomb deformation，and verifies the local surface fitting method of super-honeycomb deformation limits. The results show that the quantitative analysis model of aramid honeycomb deformation capability，with deflection deformation fitting as the core，has good applicability for predicting the matching state of honeycomb-layered structures. For cases where the slope of the honeycomb deflection fitting curve is less than the transition slope of the layer，honeycomb yield milling has a positive impact on the bonding quality of the transition region of the layer，but different forms of yield milling do not produce significant differences in bonding quality. The relevant results have certain reference value for structural design and process design of honeycomb sandwich structures.

The effective implementation of the policy on normal university students' education is a crucial guarantee for promoting pre-service teacher's education and the professionalization of the teaching workforce. However, there exists a certain conflict between the current policy and the practical context. This research will integrate the "ambiguity-conflict" theoretical model with the dynamic implementation of the policy on normal university students' education. The results show that since 2007, China's normal university students have gone through three stages. They are experimental implementation featuring the goal-oriented pluralism and co-existence shortly compatible with subjects' interests, symbolic implementation highlighting the need for urgent and refined procedural operations and the conflicts of subjects' interests, and political implementation characterized by the transformation and optimization of the system and persistently high default rates. Among them, barriers to consensus and discretionary powers play crucial roles in the bottom-up transition from experimental implementation to symbolic implementation. Also, clear and standardized policy texts and the continuous empowerment of the implementing entities contribute to the top-down transition from symbolic implementation to political implementation. Based on this, this study proposed a conception of optimizing the implementation mode policy for normal university students. That is, the central government and affiliated normal universities collaborate to promote the local influence of normal university students' education policies, the local governments and local normal universities transform the nature of conflicts to promote the active implementation of government-funded teacher education policies with Chinese characteristics, and continuously improve the meta policies and supporting policy groups of normal university students'education.

Objective: Improving the setting value adjustment ability of the speed control loop and temperature control loop of food entering the freezing tunnel. Methods: By treating the speed and temperature control circuits of the conveyor belt separately, a fuzzy control system for food freezing temperature control was designed. The control system included a proportional-integral-differential controller for the food conveyor roller speed, a proportional-integral controller for temperature regulation in the freezing tunnel, and a Takagi-Sugeno fuzzy controller to set the temperature set point of the temperature regulation proportional-integral controller. Results: When the mass flow rate of frozen food was increased from 650 kg/h to 700 kg/h, and the speed of the drive roller being increased from 1.62 r/min to 1.75 r/min, the final food temperature could be quickly restored to about -18 ℃. When a temperature disturbance of +5 ℃occurred at the food inlet, the fuzzy controller acts to keep the food outlet temperature near the expected value of -18 ℃. In summary, by selecting system parameters that allow fast response and relatively low overshoot, the designed control system can realize that the value of the output variable does not fluctuate greatly near the set value. Conclusion: The research results can be used to develop the food freezing temperature control system in the food processing plant of the cryogenic freezing tunnel, and improve the ability of food freezing temperature control.

Objective To analyze the diagnostic efficacy of orthostatic X⁃ray radiography in lumbar spondylolisthesis. Methods Sixty patients with lumbar spondylolisthesis diagnosed by Xuanwu Hospital of Capital Medical University from January to October 2020 were included. The orthostatic X⁃ray and supine CT sagittal reconstruction imaging data were collected, and the Marique. Taillard method was used to measure the relative spondylolisthesis distance (dd') and the length of the upper edge of the inferior vertebral body (cd) on the X⁃ray and CT image post⁃processing workstation. Finally, the degree of spondylolisthesis and the detection rate of lumbar spondylolisthesis based on the subjective readings of doctors in different body positions were calculated. Results Compared with the supine CT sagittal reconstruction parameters, the dd' value (Z=5.918, P=0.000), cd value (Z=4.082, P=0.000) and spondylolisthesis (Z=6.064, P=0.000) were significantly improved. The positive rate of lumbar spondylolisthesis was 95% (57/60), which was higher than 81.67% (49/60, P=0.039) of the supine CT sagittal reconstruction. Conclusions Orthostatic X⁃ray radiography can increase the lumbar vertebra stress of patients, which is beneficial to reflect the degree of spondylolisthesis of vertebra under daily stress conditions and improve the positive rate of lumbar spondylolisthesis. If combined with supine CT sagittal reconstruction, it can be used for clinical diagnosis and provide more detailed imaging data to assist in formulating targeted surgical treatment plans.

Objectives: More convenient and effective non-invasive diagnostic methods are essential for the detection and prognosis of cancer. This study aimed to mine the information in plasma cfDNA to find novel biomarkers for the diagnosis of esophageal cancer (ESCA). Methods: Blood samples were collected from esophageal cancer patients and healthy individuals. SALP-seq method was used to construct libraries and sequence cfDNA samples from 40 esophageal cancer patients and 10 normal cfDNA samples, and mutation analysis was performed. Results: Esophageal cancer related mutational signatures and 52 mutated genes were identified. Many of these genes are known cancer-related genes. Mutations in these genes were also found in 11 additional ESCA cfDNA samples. Conclusion: SALP-seq based cfDNA mutation analysis can obtain reliable and verifiable biomarkers for ESCA. These biomarkers provide a novel reference for the diagnosis of esophageal cancer, as well as offer novel insights into understanding the cellular and molecular mechanisms of esophageal carcinogenesis. Finally, our method provides a new avenue to explore novel cancer biomarkers.

Grain production is important role in ensuring food security. In order to support the local government’s promotion of technological innovation on the rice plantations, the paper aims to evaluate chemical fertilizer reduction and productivity improvement technology modes in a rice paddy in Huai’an Jiangsu from the perspective of its evaluating the social economic effects. Firstly, a brief introduction of the rice plantation requirements including fertilizer and soil requirements, are introduced. Secondly, briefly introduce the most important factors impact rice technological modes including (Economic benefit, Social benefit, Technical characteristics, and management) are briefly discussed. Thirdly, details of multi-correlation of social economic model based on gray correlation analysis for the promotion of organic fertilizer to replace part of the chemical fertilizer technology, followed by the special fertilizer mode, and the other three technology modes. Results show that among the final weights obtained through the gray correlation weighting method, the economic benefit index was 27.15%, followed by the social benefit index with 21.45%, the technical feature index has the highest weight of 34.24%, and the management index with the lowest weight was 17.16%. The evaluation scores of the five technical modes, the ranking of their comprehensive evaluation score from high to low is mode 2 (0.305925) > mode 1 (0.240125) > mode 4 (0.179925) > mode 5 (0.1447) > mode 3 (0.129825). The application of mode 2, that is, the organic substitution of partial fertilizer technology, ranks the first among the five technical modes in the comprehensive evaluation; therefore, it is worthy of prioritization.

BackgroundBecause of the excellent properties of lead-based materials as reactor coolants, lead-based fast reactors have become a key type of fourth-generation advanced nuclear energy systems. A small passive long-life Lead–bismuth -cooled fast Reactor (SPALLER) is designed by the University of South China for profound research.PurposeThis study aims to improve the inherent safety and cost-effectiveness of lead–bismuth-cooled fast reactors, and determine the maximum core power of this kind of reactor.MethodsFirstly, the SPALLER was taken as research object, and five steady-state limitations and two accident limitations were proposed to meet the transportation size, material durability, and long-term operational stability of the reactor core and ensure safety under accident conditions. Then, a neutronics maximum power calculation platform was built through Latin hypercube sampling and a Kriging proxy model whilst the steady-state limitations were considered as multi-objective optimization problems with complex multidimensional nonlinear constraints. Meanwhile, the neutronics maximum power and natural circulation power of SPALLER-100 at different core heights were calculated by taking the natural circulation ability of SPALLER-100 into account. Finally, a design scheme was obtained to meet the requirements of neutronic and thermal-hydraulic assessments of this reactor while producing maximum power. Consequently, during the full life-cycle of SPALLER-100, a safety analysis of three typical accident scenarios (loss of heat sink, transient over power, and coolant inlet temperature undercooling) was performed using a quasi-static reactivity balance approach.ResultsThe results show that the maximum core power can be increased from 100 MW to 120 MW, and the neutronics maximum power calculation platform has high accuracy with safe and economical maximum power scheme.ConclusionsThis study can provide reference for other types of natural circulation reactors to maximize power output.

The paper corrugation tube is an innovative kind of energy absorbing structure and shock absorber which can play an important role on the cushioning energy absorption for airdrop equipments and transportation packaging. The deformation characteristics and failure modes of the regular triangle, quadrangle, pentagon and hexagon paper corrugation tubes were comparatively studied by a series of axial static compression experiments, the cushioning energy absorption was evaluated by the seven characteristic parameters (e.g. initial peak force, mean crush force, total energy absorption, specific energy absorption, crush force efficiency, unit area energy absorption and stroke efficiency), and the influences of tube direction, cross-sectional shape, tube length and compression rate on failure modes and cushioning energy absorption were analyzed and compared. These researches showed that the tubes along X direction only have the accordion deformation mode, yet the tubes along Y direction have four deformation modes including steady state progressive buckling, Euler buckling, angular tear and transverse shear. For the paper corrugation tubes along Y direction, the cross-sectional shape has obvious influence on the cushioning energy absorption of structures, and the specific energy absorption and unit area energy absorption of regular triangle and pentagon tubes are better than those of the tubes with regular quadrilateral and hexagonal cross-section at compression rates of 12 and 48mm/min. The tube length of 150 mm or compression rate of 72 mm/min would cause the increase of contribution proportion of non-ideal deformation mode and the decrease of cushioning properties. The paper corrugation tubes along X direction have more stable and controllable deformation mode, yet the paper corrugation tubes along Y direction have better cushioning energy absorption.

Further dissection of physiological molecular mechanisms is indispensable to alleviate rice yield losses resulting from cold injury. By using 105 near-isogenic lines (NILs) derived from a backcross between cv. Lijiangxintuanheigu (LTH) and cv. Towada, we detected quantitative trait loci (QTLs) for physiological traits of the rice flag leaf, based on polymorphic simple sequence repeat (SSR) markers, inclusive composite interval mapping (ICIM), mixed composite interval mapping (MCIM) approaches and phenotypic value subjected to combine with cold-water stress and three nitrogen application rates. By using ICIM, a total of 34 QTLs with additive effects (A-QTLs) were identified on chromosomes 1, 3, 4, 5, 6, 7 and 10, and the phenotypic variation (R2) explained by each QTL ranged from 8.46 to 29.14%. By using MCIM, 20 A-QTLs and 14 pairs of QTLs with epistatic × environment interaction effects (Epistatic QTLs) were detected, the contribution of environment interaction (H2AE) was 0.87 to 7.36%, while the contribution rates of E-QTL were from 0.97 to 3.58%. Fourteen A-QTLs were detected by ICIM and MCIM, which may serve as a basis for fine-mapping and candidate gene studies, and providing strategies for the development of cold-tolerant rice cultivars and nitrogen application to alleviate chilling stress.

Ternary rare earth coordination chain transfer polymerization system of neodymium 2,5-dimethyl-2-ethylcaproate / diisobutyl aluminum hydride / dichlorodimethylsilane was used, and the ring opening polymerization of dicyclohexlactone 4,4ˊ- dioxane heptyl-7,7ˊ- dione (BOD) was successfully initiated, the star polybutadiene with polyester cross-linked core structure was prepared. The results showed that the weight average molecular weight of the star polymer increased gradually with the increase of the amount of BOD in the polymerization reaction. At the same time, due to the inconsistent number of arms of the star polymer, the molecular weight distribution became wider. In addition, the Mark-Houwink equation parameter α of star polybutadiene were obtained. It is significantly smaller than linear polymer, but agreed well with the α of traditional star polymer.

While the multi-point access to urban underground roads solve traffic congestion, the pollutants (CO, NOx, etc.) emitted during tunnel travel also pose environmental and health risks to the tunnel drivers and passengers as well as the residents near the tunnel openings. To this end, this study focuses on the environmental safety of urban underground roads with multiple points of entry and exit as the focus of research, based on the law of conservation of mass, fluid dynamics and ventilation engineering theory and simulation of experimental research methods, combined with motor traffic and pollutant (CO, NOx, etc.) emission characteristics, proposed NO concentration prediction model, combined with the urban underground road air flow and ventilation system operating characteristics, the longitudinal distribution law of pollutant concentration along the tunnel is calculated through case analysis, the intelligent control strategy of the ventilation system is proposed. The results show that when the traffic flow reaches 2000veh·h-1, two fans need to be started, and the power consumption is 50% less than that of the whole fan. It is expected to provide a reference basis for the design and efficient low-carbon operation of ventilation system design for urban underground roads with complex structures.

Based on the urban railway transportation vehicle wheel,three kinds of typical wheel plate（ straight plate,single S plate and double S plate） were set up. The study presents the calculation method of structure load and thermal load of the urban railway transportation vehicle wheel,and focuses on the thermal-mechanical coupling performance of the three types of wheel plate under different abrasion,the characteristic of the thermal-mechanical coupling stress is obtained under the thermal-mechanical coupling condition. The results show that three kinds of urban railway wheels are all satisfied with the requirements of fatigue strength; and the double S plate wheel has a better anti-fatigue performance than straight plate and single S plate wheel in the coupling field.