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The extraction and decolorization conditions for Spirulina platensis polysaccharides using hot alkali and hydrogen peroxide were investigated, and the process was optimized. Based on the results of a single-factor test, the yield and decolorization rate of polysaccharides were taken as indices to optimize the technological conditions for extracting polysaccharides from Spirulina platensis using the hot alkali method and decolorizing them with hydrogen peroxide using the response surface methodology. The optimal conditions for hot alkali extraction of polysaccharides from Spirulina platensis were determined as follows: NaOH concentration of 1.5%, extraction temperature of 90 ℃, extraction time of 4 hours, and material-to-liquid ratio of 1:20 g/mL. Under these conditions, the yield of polysaccharides from Spirulina platensis was 5.18%±0.23%. The optimal conditions for decolorization using hydrogen peroxide were found to be: 17% hydrogen peroxide solution, decolorization time of 55 minutes, and decolorization temperature of 50 ℃. Under these conditions, the actual decolorization rate was 82.54%±0.03%, and the retention rate of polysaccharides was 83.45%±0.13%. The findings of this study provide valuable insights for the development and utilization of Spirulina platensis polysaccharides.

In this study, the quality of high-temperature Daqu in Northern China was targeted for enhancement, with the aim of subsequently improving the quality of sauce-flavor liquor. This was achieved by incorporating No.1 Bacillus velezensis, No.2 Bacillus amyloliquefaciens and the control without exogenous spore addition during the Daqu production process. A comparative analysis of different Daqu samples was conducted using physicochemical index determination, high-throughput sequencing technology, and gas chromatography-ion mobility spectrometry (GC-IMS). The findings revealed that in Fortified Daqu No.2, the physicochemical indices including saccharification, liquefaction, fermentation, and esterification capabilities were significantly elevated compared to Fortified Daqu No.1 and the control Daqu. Additionally, a decrease in Daqu acidity was observed following spore addition. High-throughput sequencing and microbial counts showed that Bacillus populations in Fortified Daqu No.2 reached 4.2×108 CFU/g, and the abundance ratio was 21.68%. In contrast, Fortified Daqu No.1 contained 2.3×108 CFU/g Bacillus, and the abundance ratio was 18.92%, while the control Daqu exhibited 4.4×107 CFU/g Bacillus and the abundance ratio was 7.48%. Analysis of the GC-IMS three-dimensional spectra indicated that both the content and variety of flavor compounds in the two Fortified Daqu samples were markedly higher than those in the control Daqu. Furthermore, multiple characteristic pyrazines were identified in Fortified Daqu No.2 based on fingerprint analysis. In brief, the addition of exogenous Bacillus subtilis has improved the physical and chemical indicators, microbial indicators, and volatile flavor compounds of the two types of Fortified Daqu, improving the quality of high-temperature Daqu in Northern China.

In order to prepare a composite film with good mechanical properties and preservation properties, different bleached shellac/sodium alginate composite films were prepared by taking 1.5% sodium alginate as the base film solution, adding different concentrations of bleached shellac particle emulsion, and loading antioxidant tocopherol. Then the mechanical properties and permeability were compared, and the structure was characterized through FTIR spectroscopy analysis and SEM testing. The differences in preservation effects on cold fresh meat were also compared. The results showed that the composite film with 5% bleached shellac content had better properties, including mechanical properties, 37.37% reduction in transmittance and 43.00% increase in utraviolet ray barrier compared with PE film, and better CO2/O2 selectivity. And the microstructure characterization of the composite films were mutually confirmed with their performance. Using this film to pack chilled pork for preservation can effectively reduce the TVB-N content, drip loss, pH value and metmyoglobin content, and increase the shelf life to 9 days. This work has certain reference significance for the development of edible film and benefits for slowing down the spoilage of chilled pork during storage, protecting the color and taste of pork, and enhancing its nutritional value.

In this experiment, dried bracken was used as the raw material, and an ultrasound-assisted method was used to extract and calculate the extraction rate of bracken crude polysaccharides. The bracken polysaccharides were then purified using the Sevage method, macroporous resin, and dialysis method. Chemical composition and physicochemical properties of bracken polysaccharides were determined. Infrared spectroscopy, Congo red test, high performance liquid chromatography, periodic acid oxidation, iodine-potassium iodide reaction, and other methods were used to characterize the structure of bracken polysaccharides, and the antioxidant capacity of bracken polysaccharides on DPPH free radicals, ABTS+ free radical scavenging ability, and FRAP ability were measured in vitro. The extraction rate of bracken crude polysaccharides was 8.91%, the content of purified bracken polysaccharides was 76.95%, the total phenolic content was 1.03%, the content of flavonoids was 1.90%, the sulfate content was 21.38%, and the content of uronic acid was 29.26%, according to the experimental results. The infrared spectroscopy results revealed that bracken polysaccharides had typical polysaccharide absorption peaks, as well as uronic acid and partial pyranose. The monosaccharide composition results revealed that bracken polysaccharide was a heteropolysaccharide made up of ten monosaccharides. Long side chains, more branched chains, complex chain structure, and no three-stranded helix structure of bracken polysaccharide. In vitro antioxidant testing revealed that bracken polysaccharides had a high ABTS+ radical scavenging ability (up to 92.61%), a good iron ion reduction ability (40.15±1.40 mg/g in Trolox equivalent), and a high DPPH free radical scavenging ability. The above findings will serve as a foundation for further research into the structure-activity relationship of bracken polysaccharides, as well as a theoretical reference for the rational use of bracken resources.

Camellia oleifera seed meal as the main by-product of tea oil production, contains a large amount of unused high-quality plant protein. To explore the effects of ultrasound and enzyme treatment on protein during the extraction process, alkali dissolves acid precipitation (ADAP), enzyme extraction (EE), ultrasonic alkali dissolving acid precipitation (UADAP) and ultrasonic enzyme extraction (UEE) were used to extract protein from Camellia oleifera seed meal, and the structural and functional properties of the protein were compared and analyzed. The results showed that after ultrasonic treatment, the infrared peak of the amide I band shifted from 1629 cm−1 to 1649 cm−1, and the exposure of Trp residues within the protein molecules led to an increase in the fluorescence intensity of the protein. The proportion of ionic bonds in the intermolecular force increased to 31.17%. However, enzymatic treatment and alkali soluble acid precipitation treatment had little impact on the structure of protein, and there was no significant difference between the two methods. Through the comparison between ADAP group and UADAP group, it could be found that the emulsification, the gel hardness and the gel elasticity of protein increased by 34.43%, 51.36% and 38.13% after ultrasonic treatment, respectively. From the results of ADAP and EE groups, it was found that the emulsifying stability and foaming ability of the protein increased by 93.35% and 44.28% by enzymatic treatment, respectively, while the bubble stability of the protein increased by 53.11% after alkali soluble acid precipitation treatment.

Perilla frutescens (L.) Britt. is one of the edible and medicinal plants. The purpose of this study was to compare the flavonoids and polyphenols extracted from different varieties of P. frutescens leaves ('Korean green PF1', 'Chinese PF2', 'Korean purple PF3', 'Korean bicolor PF4', 'Chinese bicolor PF5'), and to explore their antioxidant activities in vitro. Optimization of extraction process of flavonoids and polyphenols from P. frutescens leaves was studied by single factor tests and orthogonal test. The results showed that the optimum parameters were ethanol concentration 75%, solid-liquid ratio 1:80 g/mL, extraction time 2 h, extraction temperature 70 ℃. Under these conditions, the extraction amount of flavonoids and polyphenols was the highest, which were (16.82±0.60) mg/g and (80.42±2.66) mg/g, respectively. Among different varieties of P. frutescens leaves, PF3 had the highest content of polyphenols (17.77±0.29) mg/g, PF5 had the highest content of flavonoids (80.42±2.66) mg/g. The results of antioxidant activity showed that the leaves of different varieties of P. frutescens had good antioxidant activity. Among them, the ABTS+ free radical scavenging rate (IC50 150.31±2.46 μg/mL), DPPH free radical scavenging ability (IC50 88.04±3.61 μg/mL) and total reducing power of PF5 were the strongest (P

Objective To explore the prediction of clinical red blood cells (RBCs) consumption under major public health emergencies, so as to provide scientific basis for blood collection and blood inventory management. Methods The clinical consumption of different types of RBCs in Yichang from 2001 to 2017 was analyzed and modeled using the recurrent neural network (RNN) model, and the clinical RBCs consumption between January 2019 and December 2021(36 months) were scientifically predicted. Results The RNN model showed good prediction performance. The root mean square errors (RMSE) of RNN prediction values of A, B, O, AB type of RBCs were 156.7, 133.4, 204.2 and 51.3, respectively, with the average relative errors (MRE) at 6.4%, 6.6%, 8.5% and 7.1%, respectively. The model predicted the changing trend of RBCs consumption during the first round of COVID-19 outbreak (January to June, 2020) and forecasted the lowest level of consumption in February 2020 and a subsequent recovery in growth. The prediction of RBCs consumption during the second round of COVID-19 pandemic (January to June, 2021) was of high accuracy. For example, the relative errors of RNN models for A type RBCs consumption were 5.2% in Feb 2021 (the lowest level, 1 621.5 U) and 2.5% in May 2021 (the highest level, 2 397.0 U). Conclusion The artificial intelligence RNN model can predict clinical RBCs consumption well under major public health emergencies.

Aiming at the problem of low amount of information carried by the existing block timestamp interval hiding method, a multi-address time-based blockchain covert communication method was proposed.Firstly, the ciphertext was split and transmitted by different addresses.The content of the ciphertext fragment was represented by the block timestamp interval of the address.Then the interval of the blocks was read and counted by the receiver where these addresses were located.Finally, the ciphertext was restored by combination.In addition, in view of the lack of concealment measures in the time-based blockchain covert communication system, a method of adjusting the time interval of transaction initiation was proposed to reduce the probability of address specificity caused by covert communication behavior.The experimental results verify that the transmission rate of the proposed method is about n times higher than that of the time-based blockchain covert communication method when n addresses are involved.

With continued progress of exploration degree on the western slope of Xihu Sag of East China Sea Shelf Basin, exploration strategy has gradually changed from structural reservoirs to structural-lithological composite ones. Through the systematic evaluation of the hydrocarbon-generating potential of coal-measure source rocks, it was concluded that coal seams and carbonaceous mudstone are the main source rocks in this area. According to the study of sedimentary system based on the "Source-to-Sink" system, 8 types of structural-lithological composite trap were proposed. Furthermore, the accumulation conditions and distribution characteristics of oil and gas were studied, it is then confirmed that effectiveness of trap is the main controlling factor for oil-and-gas accumulation in the upper and middle members of Pinghu Formation, while the hydrocarbon-supplying capacity and physical properties of reservoir are the main controlling factor in the lower member of Pinghu Formation. Consequently, a comprehensive evaluation system was established. By the means of the comprehensive evaluation of structural-lithological composite reservoirs, the Eocene-Paleocene delta in Yingcuixuan area of the northern segment of the western slope belt, the Eocene tidal flat-delta in Pingnan, Chuyang and Baoshi areas, and the inner zone of Pinghu slope are large-scale reserve areas, which is valuable and favorable for further exploration.

Understanding of sedimentary environment is the basis of oil exploration and development. Previous research on the characteristics and distinguishing of single sedimentary system by using logging curves and seismic data was mostly carried out on the determined sedimentary system. However, for the river-tide controlled cases, when the main bodies of fluvial and tidal actions are unclear, sedimentary systems are rarely studied. Based on the difference of the oscillation frequency of tide and river water bodies, combined with the correlation between the logging curves of gamma ray and the mud content as well as the influence on seismic facies by hydrodynamic strength and the difference of the size and scale of river-tide controlled delta, a geophysical method on the basis of natural gamma log difference (ΔGR) and seismic facies wave length/height ratio is proposed to distinguish river-tide controlled delta sedimentary systems. A case study was carried out with the sedimentary system of the Pinghu Formation in Pingbei area of the Xihu Sag, East China Sea Shelf Basin, and it was concluded that this method can effectively distinguish river-tide controlled delta system. At the side edge of the underwater low uplift, Baoyunting low uplift, relevant parameters have been effectively picked up to distinguish the river-tide controlled delta system, and to identify the tidal channel development zone and potential targets for channel filling. It is clear that the identification of river-tide controlled system has an indicative significance for the prediction of lithologic traps and favorable reservoir units.

The Xihu Sag has huge exploration potential and is the main target for oil and gas exploration in the East China Sea Shelf Basin. At present, it has been known that the Xihu Sag has a transitional facies with sedimentary system mainly composed of tidal flat deposits, and the provenance of which is dominated by western and northern uplift area. However, the transport process of sands from source area to deposit area, namely "source-channel-sink" system, has not been well studied. In this study, we take the Pinghu Formation of Baochu slope belt in the Xihu Sag as research object, and use borehole and seismic data to preform high-precision restoration of palaeo-geomorphology. Moreover, on the basis of palaeo-geomorphology restoration, we make qualitative and quantitative analyses of palaeo-water-system and palaeo-break. Results show that the location of sink zone is controlled by palaeo-geomorphology, the distribution of sand transporting channel is controlled by palaeo-water-system, and the development of sedimentary facies is controlled by palaeo-break. Through comprehensive analysis, we suppose that the combination of "palaeo-geomorphology, palaeo-water-system and palaeo-break" restricts the process of sand body deposition from provenance to convergence area through river transportation, and controls the distribution of the sedimentary system of Baochu slope belt.

Flow-like motion is the main forms of rock avalanche emplacement, which is the foundation to reveal the dynamic mechanisms of rock avalanches. In this paper, a series of physical modeling experiments based on the Particle Image Velocimetry（PIV）analysis method are conducted to research the internal velocity distribution, internal shear behavior and flow regimes of the granular flow under different grain size conditions. The flow-like motion of rock avalanches and the corresponding deposit features are further discussed and analyzed based on the experimental results. The research results show that the flow-like motion of the granular flow is significantly correlated with the grain size. With the decreasing grain size or the increasing fine particles content, the slip velocity at the bottom of the granular flow and the bulk velocity decrease gradually, the degree of internal shear of the granular flow increases, and the motion form of the granular materials changes from “sliding” to “flowing”. When the grain size is smaller or the content of fine particles is higher, the increasing trend of the internal shear rate is more prominent at the bottom of the granular flow, which indicates that the reduction in grain size promotes shear localization at the bottom of the granular flow. The granular flow regime is different at different locations of the granular flow. The leading and trailing edges of the granular flow are mainly inertial regime, and the interaction between particles is dominated by collisions, while the particle interactions in the main body is dominated by frictional contact. On the surface and bottom of the granular flow, the interaction between particles is mainly collision, while particle interaction in the middle part is mainly frictional contact. For the granular flow with different grain sizes, with the increasing grain size and coarse particles content, the particle collisions in the granular flow are enhanced, and the flow regimes tend to be more inertial.

Aiming at the problem of insufficient research on the knowledge base of distributed denial of service (DDoS) network attacks, a method for constructing a knowledge base of DDoS attacks malicious behavior was proposed.The knowledge base was constructed based on the knowledge graph, and contains two parts: a malicious traffic detection database and a network security knowledge base.The malicious traffic detection database detects and classifies malicious traffic caused by DDoS attacks, the network security knowledge base detects DDoS attacks from traffic characteristics and attack frameworks model malicious behaviors, and perform inference, tracing and feedback on malicious behaviors.On this basis, a distributed knowledge base was built based on the DDoS open threat signaling (DOTS) protocol to realize the functions of data transmission between distributed nodes, DDoS attack defense, and malicious traffic mitigation.The experimental results show that the DDoS attack malicious behavior knowledge base can effectively detect and mitigate the malicious traffic caused by DDoS attacks at multiple gateways, and has the knowledge update and reasoning function between the distributed knowledge bases, showing good scalability.

Measuring electric fields in the space environments of the Earth and other planets helps us to understand the electric field structures and plasma waves in the space. An addition usage of data from electric field measurements is to derive the cold ions in the magnetosphere which are invisible to ordinary energy spectrometers. The cold ions of ionospheric origin dominate the ion population in the magnetosphere. They are accelerated by the ambipolar electric field in the ionosphere to escape velocities. The loss of cold ions plays an important role in evolution of the atmosphere and habitability. In this review, we summarize two types of electric field instruments being widely used in space exploration, and the method to derive parameters of cold ions in the magnetosphere from the measurements made by the two types of electric field instruments. Based on existing technologies, we propose a new instrument to measure the ambipolar electric field in the polar region with a magnitude of about 10−6 Vm−1. This new instrument may be onboard a future satellite operating in the polar region, and give us clues on evolution of atmosphere and habitability.

The granular flow thickness and its evolution trend are key factors in analyses of the physical model experiments of avalanches. At present, the measurements of granular flow thickness mainly include sensor monitoring, mechanical measurement and manual measurement. With the development of computer technology, digital image processing methods have been applied in more and more subjects including engineering geology. In this paper, a series of granular chute flow experiments are conducted for the extraction of granular flow thicknesses. Based on the digital image processing methods including adaptive median filter, image binarization, image erosion and seed filling, the granular flow image sequence recorded by the high-speed camera is processed and analysed with related codes compiled, thereby achieving continuous extraction of flow thickness during the granular flow propagation. The results show that the granular flow thicknesses extracted with the digital image processing methods are consistent with the measured true thicknesses in the main bodies of the granular flows. Some deviations appear in the tail of granular flow accompanied by significant particle dispersions. The deviations are mainly attributed to the fact that some particles in the three-dimensional space show overlapping phenomenon in the two-dimensional image, which results in the illusion of granular continuity. In general, the granular flow thicknesses obtained with the digital image processing methods is of a high accuracy in the densely packed granular flows. Compared with other methods, this method is of higher efficiency, higher sampling rate and lower disturbance on granular flows. In addition, additional parameters, such as velocities and displacement, can be obtained simultaneously. Therefore, this method can be used as one of the conventional methods to obtain kinematic parameters in granular flow experiments.

Background and objective Targeted therapy for patients with driver genes positive and immunotherapy for patients with driver gene-negative but high programmed death ligand 1 (PD-L1) expression are the standards of first-line treatment for patients with advanced non-small cell lung cancer (NSCLC). The treatment options for patients with driver gene positive and high PD-L1 expression are still worth exploring. Methods The characteristics of 315 patients with NSCLC were identified to analyze the clinicopathological characteristics of patients with driver gene positive and high PD-L1 expression, and the efficacy of targeted therapy. Results Among the 315 patients, the total positive rate of driver genes was 62.2%, and the high PD-L1 expression rate (≥50.0%) was 11.2%. The proportion of patients with driver gene positive and high PD-L1 expression was 10.7%. PD-L1 was highly expressed in patients with epidermal growth factor receptor (EGFR) mutation, KRAS mutation, ALK fusion, BRAF mutation, and MET 14 exon skip mutation, the proportions were 7.8% (11/141), 18.2% (4/22), and 23.1%, (3/13), 50.0% (2/4) and 100.0% (1/1) respectively. EGFR mutation positive with PD-L1 high expression was mainly in patients with stage IV lung adenocarcinoma. KRAS mutation positive with PD-L1 high expression was mainly in patients with a history of smoking. Among them, two patients were followed in detail for targeted therapy, who with ALK fusion-positive and PD-L1 high expression (90.0%), EGFR L858R mutation and PD-L1 high expression (70.0%) respectively. The total OS of the patients was 5 months, 2 months. Conclusion The high PD-L1 expression rate in NSCLC patients with different driver gene mutations was variable, which maybe correlated with distinct clinicopathological characteristics. Patients with sensitive mutations and high PD-L1 expression may be less benefit from targeted therapy and have poor prognosis.

B2B business model in 5G era will become the main competition area for operators.Opportunities come along with challenges from investment,market and technology such as huge construction expenditure,fragmented market and difficulties of industry integration.Research on B2B operation cases of domestic and foreign operators and internet giants in the post 4G and 5G era had been done,from which “communication +” service model,industry coordinator model and platform model were investigated especially.Finally,three B2B operations models of domestic operators were proposed.

As the mainstream of the sixth generation mobile communication development,intelligent communication assisted by artificial intelligence technology is vigorously developing,and has initially demonstrated its advantages over traditional communication methods.As an important component of intelligent communication,artificial intelligence assisted channel estimation shows its superiority over traditional channel estimation algorithms in the existing research results,especially those researches based on compressive sensing technology,super resolution technology,residual learning,etc.Aiming at the channel estimation technology assisted by artificial intelligence,combined with the latest research results in the academic field,the whole picture of the channel estimation technology assisted by artificial intelligence from the four dimensions of deep convolution neural network,deep recurrent neural network,super-resolution technology and compression sensing technology were showed.Finally,the advantages and disadvantages of four kinds of channel estimation methods and their future research directions,and the broad prospect of the combination of channel estimation and deep learning were looked forward.

“Endogenous security” gives the information network the ability of self-learning and self-growth,and it’s the important part of building a trusted intelligent communication network.“Endogenous security” was combined with malicious behavior detection,and an endogenous detection framework of malicious behavior with endogenous security capabilities was proposed.Passive defense was turned into active interception.In addition,the five key components in the endogenous detection framework were also modeled and analyzed,and explained the self-learning and self-growth malicious behavior detection mechanism.Finally,the deployment method of the prototype system was introduced.Preliminary test results show the proposed framework is feasible and effective.

A low exploration success ratio on the Baochu Slope of Xihu Sag of East China Sea has been inferred, and the ratio in the Central Anticline Belt varies significantly in different sub structures. To solve this issue, the petroleum geologic conditions of the sag were systematically reviewed in light of new basin analysis methodologies, and new understanding have been achieved. Due to the differences in tectonic features and evolution histories, the Baochu Slope and Central Anticline Belt developed different petroleum systems and play types. Only those areas with overlapping favorable fairways of all petroleum system elements promise the formation of large oil and gas fields. The Baochu Slope is featured by tectonic rifting, with weak later compression and early structure formation. Its favorable conditions for hydrocarbon accumulation include: short distance to the main source kitchen; multiple, overlapping, large-scale reservoirs; multiple structural-stratigraphic trap types; good vertical sealing zones; and effective lattice pattern migration pathways. The large to medium structural-stratigraphic fields are concentrated in fairways with a large scale source kitchen and updip pinchout of tide-dominated delta sands controlled by paleo slope break which in turn were induced by either faulting or paleo morphology. The Central Anticline Belt has experienced strong inversion and compression during the late depression stage, and developed inverted compressional slip faults and large scale anticlines. Hydrocarbon accumulation is controlled by four major factors: preexisting structural highs before the compressional event, large scale structural-lithological traps, excellent timing of hydrocarbon charging during deformation, and highly effective reservoir-seal combinations. The areas with good congruence of these contro-lling factors promise the occurrence of large-scale deposits such Longjing, Guzhenzhu, Huxinting fields.

With the development of industrial internet technology,5G and edge computing,countries have put forward their own industrial Internet development strategies and construction of industrial Internet platform.Cloud edge collaborative industrial Internet platform is an important part of the development of industrial Internet.The way of industrial Internet cloud edge collaboration was introduced,the problems in the process of cloud edge collaboration were expounded,and practices were taken based on data collaboration and model collaboration.

Background and objective The patients with advanced lung adenocarcinoma should select targeted drugs based on the type of tumor epidermal growth factor receptor (EGFR) gene mutation. However, it is difficult to collect tumor tissue of advanced lung adenocarcinoma, and some experts agree that peripheral blood can be used as a substitute for tumor tissue as a test specimen. This paper aimed to investigate the clinical value of ddPCR and super-amplification refractory mutation system (ARMS) in detecting EGFR gene mutation in peripheral blood of patients with advanced lung adenocarcinoma. Methods A total of 119 patients diagnosed in Beijing Chest Hospital Affiliated to Capital Medical University from February 2016 to February 2019 were collected, and the sensitivity and specificity of plasma ctDNA EGFR gene mutation detected by ddPCR and super-arms were compared. Some patients with positive EGFR gene mutations received oral treatment with first-line EGFR tyrosine kinase inhibitors (EGFR-TKI). The patients were divided into subgroups according to the test results. In group 1, both ddPCR and super-arms showed positive EGFR gene mutation results, with 21 cases. In group 2, ddPCR and super-arms detection of EGFR gene mutation were all negative, with 16 cases. In group 3, the ddPCR test was positive and the super-arms test was negative, with 5 cases. In group 4, the ddPCR test result was negative while the super-arms test result was positive. Since the number of patients in group 4 was 0, no statistics were included. Objective response rate (ORR) and disease control rate (DCR) were used to evaluate the short-term outcome, and progression-free survival (PFS) was compared with survival analysis to evaluate the long-term outcome. Results EGFR mutations were detected in 58 (48.7%) of 119 patients with advanced lung adenocarcinoma. The coincidence rate between ddPCR and EGFR gene mutation in tumor tissues was 82.4% (Kappa=0.647, P0.05). Survival analysis showed that the PFS of the three groups was compared. The difference was not statistically significant (χ2=2.221, P=0.329). Conclusion ddPCR, as a high sensitivity and specificity liquid gene detection method, can be used as a reliable method to detect the mutation of plasma ctDNA EGFR gene in patients with advanced lung adenocarcinoma. The results of plasma genetic testing can also be used as the basis for predicting the efficacy of EGFR-TKIs in patients.

So far,the overall informatization level of manufacturing industry has been uneven,and there are many problems such as low intelligence and poor connectivity.First of all,with the features like low power consumption of the Internet of things,the sensor devices can be deployed flexibly to realize real-time collection and transmission of production data.Then the manufacturing execution system based on the cellular industrial Internet of things had been built,and realized the closed-loop processing of human,machine,material,method and surrounding.The industrial big data of the whole production process was modeled,analyzed and processed.The operation and maintenance cost was reduced,and the production efficiency and product quality were improved.Finally,the overall efficiency of the application was evaluated which showed that the factory capacity was improved effectively.

Denial of service (DoS) attack was one of the major threats to cloud computing.Security access path algorithm (SAPA) used node route table (NRT) to compose security access path.It simplified role nodes of traditional secure overlay services (SOS),and periodically updated role nodes,and cached security access paths.Therefore,SAPA was more appropriate for cloud computing to defend DoS attacks.Based on the turn routing architecture of cloud computing,the mathematical model of SAPA was built and its performance was analyzed in theory.The performance of SAPA was tested in OMNeT++ experimental platform.Also,the Test-bed experiments were performed to evaluate the effectiveness of SAPA for defending DoS attack.Experimental results show that comparing with SOS,SAPA can degrade the impact of communication success rate caused by DoS attack effectively,and guarantees the access delay small enough.

It is essential for network managers to decide how to use a reasonable allocation of bandwidth, providing differentiated services, as well as conducting security monitor and management so as to do fine-grained and precise IT operation. The fine-grained traffic identification method proposed was able to identify the user's behavior accurately according to the traffic that the application generates. In addition, compared with the traditional x86 platform, in order to achieve higher throughput and lower power consumption, the method was redesigned and implemented in the Tilera platform with parallelization. Finally, a variety of system performance test results were compared under the two platforms.

A novel clustering scheme based on maximizing average system performance was proposed.Firstly,according to the probability distribution of signal-to-interference-ratio (SIR)gain of base stations cooperation the average SIR gains were obtained.Then,the cluster structure was generated in the standard of maximizing the average system performance.Not only the average system performance was guaranteed but also the influence of CSI distortion was decreased,while the overall cost was reduced.Simulation results show that when the factors of CSI distortion and channel vibration both are 0.3,the proposed scheme provide a 0.7bit/s/Hz/cell increase of the average system performance compared with the benefit-tree clustering scheme.

ObjectiveTo explore the expression and clinical significance of Yes-associated protein 1 (YAP1) in esophageal squamous cell carcinoma. MethodsImmunohistochemical method was used to detect YAP1 expression in 439 cases of esophageal squamous cell carcinoma. The differences of YAP1 expression and clinical parameters were analyzed between YAP1 positive group and YAP1 negative group. Kaplan-Meier curve was used to analyze the influence of YAP1 expression on survival of patients. ResultsThe positive rate of YAP1 in esophageal squamous cell carcinoma was 30.52%. The tumor invasion was deeper in YAP1 positive group (P＜0.001). Kaplan-Meier survival analysis showed that YAP1 positive patients had longer disease-free survival (DFS) and overall survival (OS) among patients surviving longer than 30 months (P＜0.05). The multivariate Cox regression analysis showed that the invasion depth of tumor was an independent factor affecting DFS (HR＝1.371, 95%CI 0.993-1.894, P＝0.035) and OS (HR＝1.489, 95%CI 1.066-2.080, P＝0.020). ConclusionsYAP1 has a certain percentage of positive rate in esophageal squamous cell carcinoma; for patients with survival longer than 30 months, YAP1 positive indicates a better prognosis.

Sugars will eventually be exported transporter (SWEET) is a novel class of sugars transporter families which mainly mediate either sucrose or hexose translocation bidirectional across the cellular membranesfollowinga concentrating gradient with a passive diffusion patten. In higher plants, SWEET proteins commonly have seven transmembrane domains that form a pore in the membrane to allow the passage of sugars, containing two MtN3/Saliva domains. Phylogenetically, plant SWEETs are divided into four clades. SWEET transporters play important roles in diverse physiological and biochemical processes including phloem loading, plant hormone transportand vegetative growth. In this review, based on the current advance of the plant SWEET transporters, we summarized their discovery, structure characteristicsand biological functions, and pointed out current research problems. Finally,put forward several better future research directions and potential solutions for SWEET sugar transporters in plant from the following three aspects: 1) exploring the molecular mechanism of substrate recognition and selectivity of SWEET proteins; 2) mining and utilizing of key SWEET genes increasing crop yield and improving quality; 3) using gene editing technology and phosphorylation of SWEET transporters to engineer high-yielding and high-quality crops.

ObjectiveThis paper analyzes and models the core logic of a strike chain in terms of time sensitivity, reconfiguration and coverage, thereby providing model and method support for improving the dynamic management ability of naval combat resources under confrontation conditions. MethodsFirst, the typical combat platforms and elements related to the cross-domain cooperative combat of naval battlefields, such as escort ships, UAVs and unmanned boats, are abstracted into four types of resource nodes, namely detection, processing, decision-making and strike. Next, taking the shortest delay as the goal and considering constraints such as wide battlespace, low transmission rate between nodes and limited communication distance, the dynamic integration optimization mathematical model of the strike chain is established. A typical air defense scenario is then designed to demonstrate the shortest delay analysis of the strike chain and the destruction reconstruction analysis under the absence or attack of nodes, and quantitatively describe the changes of the shortest delay and sector coverage index of the reorganized strike chain under countermeasure conditions. Finally, based on a typical combat example of a Ukrainian unmanned cluster attack on the Black Sea Fleet, the ability of the fleet to resist the attack is analyzed on basis of the strike chain model. ResultsThe simulation results show that the model can be used to generate multiple strike chains with the shortest delays, and the responsibility division of each strike chain can be optimized, forming a multi-target killing network at sea. The destruction reconstruction of the strike chain often needs to pay such costs as increased delay and decreased sector coverage. The model can also be used to test anti-saturation attack ability under different formations.ConclusionsThis paper studies and validates the feasibility of analyzing the naval warfare system based on the strike chain model, and can provide theoretical model support for the subsequent design of future naval joint combat systems oriented to the killing network.

In recent years, great breakthroughs have been made in the exploration and development of natural gas in deep coal-rock reservoirs in Junggar, Ordos and other basins in China. In view of the inconsistency between the industrial and academic circles on this new type of unconventional natural gas, this paper defines the concept of “coal-rock gas” on the basis of previous studies, and systematically analyzes its characteristics of occurrence state, transport and storage form, differential accumulation, and development law. Coal-rock gas, geologically unlike coalbed methane in the traditional sense, occurs in both free and adsorbed states, with free state in abundance. It is generated and stored in the same set of rocks through short distance migration, occasionally with the accumulation from other sources. Moreover, coal rock develops cleat fractures, and the free gas accumulates differentially. The coal-rock gas reservoirs deeper than 2000 m are high in pressure, temperature, gas content, gas saturation, and free-gas content. In terms of development, similar to shale gas and tight gas, coal-rock gas can be exploited by natural formation energy after the reservoirs connectivity is improved artificially, that is, the adsorbed gas is desorbed due to pressure drop after the high-potential free gas is recovered, so that the free gas and adsorbed gas are produced in succession for a long term without water drainage for pressure drop. According to buried depth, coal rank, pressure coefficient, reserves scale, reserves abundance and gas well production, the classification criteria and reserves/resources estimation method of coal-rock gas are presented. It is preliminarily estimated that the coal-rock gas in place deeper than 2 000 m in China exceeds 30×1012 m3, indicating an important strategic resource for the country. The Ordos, Sichuan, Junggar and Bohai Bay basins are favorable areas for large-scale enrichment of coal-rock gas. The paper summarizes the technical and management challenges and points out the research directions, laying a foundation for the management, exploration, and development of coal-rock gas in China.

Unmanned aerial-undersea vehicles(UAUVs), with broad application prospects in both military and civilian fields, have gradually become a research hotspot in the field of robotics in recent years. UAUVs were taken as the research object in this study, and the development status of the bionic, multirotor, fixed-wing, and hybrid UAUV prototypes were discussed. In addition, the water-entry/exit strategies of the prototypes were reviewed. The important issues faced in the research on UAUVs were summarized, including the optimal design of bionic configuration, stability control during the trans-medium process, and propulsion selection, providing a reference for the subsequent research and development of trans-medium vehicles.

ObjectiveThis study investigates the evolution of the interaction between an underwater explosion bubble and the free liquid surface in terms of compressibility and viscous effect. MethodsA numerical model of an underwater explosion bubble coupled with the free liquid surface is developed on the basis of the compressible two-phase flow solver of OpenFOAM and the volume of fluid method (VOF). The validity of the numerical model is then verified by comparison with the experimental results. The effects of different flow field viscosities and distance parameters on the bubble pulsation process and free-surface spike motion are also investigated. ResultsThe flow field viscosity effect has an important influence on the surface spike height, bubble pulsation period and bubble pulsation, especially the bubble morphology in the rebound phase. Ring bubble morphology is not easy to maintain in low viscosity fluid, so the tearing phenomenon of the bubble can easily occur. As the distance parameter increases, the coupling effect between the free surface and the bubble gradually decreases, the bubble pulsation period increases, the heights of the primary and secondary surface spikes decrease, and the widths of the primary spike and liquid jet gradually increase.ConclusionThe results of this study can provide useful references for determining the evolution mechanism of bubbles under different flow field viscosities.

To explore the influence of oxygen content on the corrosion resistance of steels, carbon and weathering steels with different oxygen contents of (20×10−6–200×10−6) were smelted. Using scanning electron microscopy inclusion analysis, polarization curve test, and full immersion test, the change rules of inclusion type, shape, quantity, size, and corrosion resistance under different corrosion environments with changing oxygen content in steel were investigated. The findings indicated that with increasing oxygen content in the steel, the inclusions in the steel changed from long strip MnS and Al2O3 to granular silicate inclusions, and the total number and mean size of all inclusions increased gradually; for instance, with the oxygen content increasing from 20 × 10−6 to 60 × 10−6 and then to 195 × 10−6, the number fraction of MnS decreased from 69.9% to 23.7% and then to 5.8%, the number fraction of silicate increased from 3.4% to 54.9% and then to 73.2%, the total area fraction of inclusions increased from 0.01% to 0.04% and then to 0.25%, and the equivalent circle diameter (ECD) increased from 0.78 µm to 1.15 µm and then to 4.65 µm, respectively. The pitting potential demonstrated a positive tendency, with an overall increase of about 40 mV. The full immersion corrosion rate first decreased and then increased, following the cubic function change rule. When the oxygen content increased from (20×10−6–30× 10−6) to 60 × 10−6, the corrosion rate of carbon and weathering steel decreased by 53% and 24%, respectively. The corrosion resistances of carbon and weathering steels were enhanced, and the corrosion rate of weathering steel was evidently lower than that of carbon steel, which is below 3 mm·a−1. With the corrosion time prolonging from 24 h to 48 h and then to 96 h, the corrosion rates of carbon and weathering steels decreased significantly, and the corrosion gradually slowed down. From the analysis, there were mainly long strip sulfides in the steel with an oxygen content of (20×10−6–30×10−6). When the steel plate experienced pitting corrosion, the sulfides exposed on the pit wall rapidly dissolved, speeding up the corrosion process. The long strip sulfides were reduced in the steel at an oxygen content of (60×10−6–85×10−6), and most of them were replaced by silicate composite inclusions that did not easily induce pitting corrosion, and the corrosion propagation was restrained, which is demonstrated by good corrosion resistance. At an oxygen content of 195 × 10−6, the average ECD of inclusions in the steel and the total area fraction of inclusions was four times and six times that of the steel with an oxygen content of 60 × 10−6, respectively. This large number of inclusions as the source of pitting corrosion leads to the steel matrix being vulnerable to severe corrosion, which is characterized by poor corrosion resistance. Thus, at an oxygen content of (20×10−6–100 × 10−6), the corrosion resistance of steel in the full immersion corrosion environment was improved due to the combined effect of the reduction of long strip sulfide that can easily induce corrosion and the increase in solid solution oxygen to increase the matrix potential. At an oxygen content of (100×10−6–200 × 10−6), the corrosion resistance of the steel was weakened due to the sharp increase of inclusions. Therefore, economical corrosion-resistant steel can be developed by increasing the oxygen content appropriately.

With the development of underwater acoustic technology, underwater acoustic networks(UANs) have attracted much attention due to their performance in marine surveillance, disaster warning, and ocean security. The underwater acoustic channel is a crucial factor affecting the performance of UANs, and its complexity directly affects the pre-design and evaluation of UAN-related protocols, which is crucial to the practical application of protocols. Unlike traditional theoretical models, the Bellhop underwater acoustic channel model provides a more accurate method to obtain channel characteristics under different oceanic environments by calculating their acoustic fields via ray tracing. However, it cannot be directly applied to network simulation. This paper implemented a Bellhop underwater acoustic channel model based on NS3, the current most popular network simulation platform, and applied the Gaussian ray model to UAN simulation. The comparison results show that the model can effectively simulate the underwater propagation characteristics of acoustic signals and provide a reference for practical UAN-related protocol development.

As brain diseases can severely affect society, studies on the diagnosis of brain diseases are gaining importance. China is focused on counteracting the issues in brain disease diagnosis and treatment. Magnetic resonance imaging (MRI) has the advantages of high resolution and noninvasive nature, making it a preferred technique for brain disease research and clinical examination, providing rich databases for brain disease diagnosis. Deep learning is used in various fields due to its scalability and flexibility, and it has shown great potential for further development. Owing to recent developments in deep learning, it has made impressive achievements in various fields, such as computer vision and natural language processing, exhibiting great potential for its development and impact on brain disease diagnosis. Deep learning is being increasingly used for the diagnosis of brain disorders. We categorized studies reporting the use of deep learning for brain disease diagnosis by the type of disease to provide insights into the latest developments in this field. We cover the following aspects in this review. First, we reviewed and summarized the application of deep learning in the diagnosis of three typical brain disorders: autism spectrum disorder (ASD), schizophrenia (SZ), and Alzheimer’s disease (AD). Second, we reviewed commonly used datasets and available open-source tools for diagnosing these three brain disorders. Finally, we summarized and predicted the application of deep learning in the diagnosis of brain disorders. The review focused on the diagnosis of the aforementioned brain disorders. ASD is a neurodevelopmental disorder that occurs in early childhood. SZ is a psychiatric disorder that occurs in young adulthood. AD is a brain disorder that commonly occurs in old age. We illustrated the application of deep learning in the diagnosis of these brain disorders based on the characteristics of their different inputs. While using MRI as an input source, most convolutional neural networks were used as backbone networks to design feature extraction methods. However, while working with data containing sequence information from many time points, recurrent neural networks were used to extract key information from the sequences. Apart from directly processing images as input, many studies extracted manual features, constructed graphs of manual features, and used graph neural networks for analysis. This approach yielded remarkable results. Moreover, our findings indicated that graph neural network–based analysis methods are being commonly used to diagnose brain disorders.

Objective To observe the effects of astragaloside （Ast）-incubated human adipose derived stem cell （hADSC） on diabetic kidney disease （DM） after caudal vein transplantation. examine the repair status of diabetic kidney disease （DKD） on renal injury in rats and elucidate its possible mechanism. Methods A total of 21 Sprague-Dawley rats were randomized into four groups of normal （n = 5）, model （n = 6）, hADSC （n = 5） and Ast-hADSC （n = 5）. DKD model was established in the last 3 groups. Both hADSC and Ast-hADSC groups were injected 6 times with hADSC or Ast-hADSC suspension through tail vein once biweekly. The model group received the same volume of normal saline. Renal function, blood lipid, urinary microalbumin/urinary creatinine and urinary protein quantification were detected. Renal pathology was observed after hematoxylin-eosin and Masson stains and renal colonization of hADSC by confocal laser. Immunohistochemistry and immunoblot were utilized for observing the voltage-dependent anion channel （VDAC） and microtubule-associated protein-light-chain-3. LC3Ⅱ/LC3Ⅰ, autophagy substrate P62 protein, phosphatase and tensin homology induced putative kinase 1 （Pink1） and E3 ubiquitin ligase （Parkin） protein expression. Mitochondria and autophagosomes were observed by transmission electron microscopy. Results （1） As compared with model group, total serum cholesterol [（2.65 ± 0.04） mmol/L, （2.30 ± 0.29） mmol/L vs （3.31 ± 0.91） mmol/L], ratio of urinary microalbumin/urinary creatinine [（58.91 ± 11.86） mg, （44.00 ± 23.82） mg vs （101.03 ± 46.88） mg] and 24 h urinary protein quantity [（321.18 ± 88.71） mg, （136.35 ± 66.01） mg vs （408.67 ± 113.95） mg] （P＜0.05） declined in hADSC and Ast-hADSC groups. Body weight gained [（240.20 ± 26.43） g, （274.00±17.89） g vs （193.60 ± 18.57） g] （P＜0.05）. The effects of body weight and 24 h urinary protein were more significant in Ast-hADSC group than those in hADSC group （P＜0.05）. （2） As compared with model group, no significant differences existed in triglyceride, low density lipoprotein, urea nitrogen or high density lipoprotein in hADSC and Ast-hADSC groups （P＞0.05）. （3） Both hADSC and Ast-hADSC groups had lesser renal injury while renal index and glomerular cross-sectional area spiked （P＜0.05）; Improvement was more significant in Ast-hADSC group. （4） Under laser confocal microscope, minimal red fluorescence was observed in hADSC and Ast-hADSC groups. （5） Immunohistochemistry and immunoblotting revealed that protein expressions of LC3, LC3Ⅱ/LC3Ⅰ, Pink1 and Parkin spiked in hADSC and Ast-hADSC groups （P＜0.05） while protein expression of P62 declined （P＜0.05）. The effect of Ast-hADSCs group was more significant. （6） In model group, mitochondria were swollen, deformed and fragmented and the number of autophagosomes was fewer. Both hADSC and Ast-hADSC groups showed more autophagosomes and fewer swollen deformed mitochondria and mitochondrial fragments. The effect of Ast-hADSC group was more significant. Conclusions hADSC may restore mitochondrial autophagy in kidney tissue of DKD rats and reduce kidney injury. The effect is more significant after Ast incubation.

In order to accurately mine outliers and reduce the impact of outliers on communication data, a multi-scale outlier mining algorithm for stateless communication data in IPv6 remote monitoring network was investigated.The stateless communication data were obtained through an IPv6 remote monitoring network, and based on the seasonality, trend, and self-similarity characteristics of the extracted stateless communication data, the Fourier transform was used to divide the stateless communication data into two classes.Then, the K-mean method was used to cluster the two classes to determine the neighborhood of the stateless communication data, which was used as the basis for outlier mining using a convolutional neural network on the stateless communication data.The convolutional neural network was initialized, and according to the output value of the convolutional neural network, it was determined whether the network met the stopping condition.The operation steps of the convolutional neural network were repeated, all the outlier points were mined, and the multi-scale outlier mining of stateless communication data was achieved.The experimental results showed that the fewer the number of stateless communication data categories, the higher the mining efficiency; the proposed method can accurately mine the number of multiscale outliers of stateless communication data in IPv6 remote monitoring network and accurately analyze the reasons for the outliers.

Aircraft landing with low fuel is usually caused by diversion decision changes in the air. It could lead to an unsafe event. To solve the problem of collective alternate landings of multiple flights in the area, the most complex situation is selected, that is, when the weather in the route or terminal area is dangerous. However, in this situation, when the pilot announces diversion, many are unacceptable by the airport due to limited aircraft stand. Therefore, this study establishes a decision-making approach to help air traffic controllers and airlines choose suitable alternate airports since accurate fly limit zone conditions can keep the aircraft out of dangerous weather and a short diversion route can avoid the low fuel situation, both of which can increase the safety of the diversion process. The basic conditions of the fly limit zone under dangerous weather are obtained by combining meteorological data and historic tracks. Here, A* and the improved gray wolf Dijkstra algorithm are used to plan the diversion path for two different routes to the alternate aerodrome: maneuvering flight and flying along the route. First, considering the shortest total flight time of alternate flight as the single objective and subsequently integrating the expectations of flight, control, airport, and airline, a multi-objective function is constructed, the dynamic decision-making time interval is defined, and a dynamic optimization scheme of multi-flight alternate in the region based on a single objective and multi-objective is proposed. The single-objective scheme focuses on the safe aspect of diversion, while the multi-objective scheme focuses on preventing airport rejection. The multi-objective scheme can enable the flight to land quickly, ensure safety, and consider the expectations of multiple parties to avoid diverting simultaneously. Using the “8.12” North China large area alternate landing data, the total flight time obtained by selecting the direct flight A* algorithm is reduced by 100 and 62 min, respectively, and the total flight time obtained by the improved gray wolf Dijkstra algorithm based on the route is reduced by 73 and 14 min. Moreover, in the multi-objective scheme, the overall time of flight resumption to the original destination is 63 min earlier, and the total cost is reduced by 62900 yuan. Although multiple diversion still occurs on CA991, the process is within the safety range. Therefore, results indicate that the scheme considers the needs of multiple parties and improves the economy to ensure the safety of flight alternate landing.

A gold mine in Subei adopts flotation process to treat ores. Recently, due to the large change of the ore properties, the size of the gold inlay becomes thicker, resulting in gold entering tailings. The gold grade of the tailings is about 0.70~0.90 g/t. Process mineralogical studies show that the main metal minerals are pyrite and chalcopyrite. The mineral composition is more complicated, and the main gangue minerals are quartz, feldspar, kaolin, etc. From the results of tailings screening, gold is mainly composed of coarse and medium-grain, which is suitable for recycling with Nelson. Under the conditions of expanding gravity multiplier 60 G, fluidized water volume 3.2 L/min, feeding rate 10 kg/h, and ore grade 0.87 g/t, a good index of 33.42 g/t gold concentrate grade and 35.27% recovery rate can be obtained.

The Maling area is located in Xingyi City, Guizhou Province.It is an idea area to study the evolution of the sedimentary environment in the Early Triassic for its sedimentary strata saddle the Permian and Triassic transition.Based on the integrations of field survey of the Jialingjiang Formation in this area, measured profile data, microscopic observation in the laboratory, and 14 major and trace elements, the evolution of its depositional environment was discussed.Carbonate rocks and clastic rocks are mainly exposed in Maling area, which can be divided into four members.A total of 16 rock samples were collected for analysis.Combined with sedimentary facies, palaeoclimate index (SiO2/Al2O3 ratio), paleosalinity index, paleobathymetric index (CaO/MgO and Sr/B aratio), the following changes are identified in the Early Triassic: ① The abnormally hot and dry climate gradually transitioned to an overall humid climate, which may be the result of the Early Triassic and the biological recovery provided suitable climatic conditions; ②The alternation of shallow sea and deep sea occurred. The first to fourth members of the Jialingjiang Formation are dominated by open platform facies, tidal flat facies, open-limited-open platform facies, and limited platform facies, respectively. The local appearance of bioclasts such as bivalves confirms that the Early Triassic marine environment in this area was abnormally variable and had multiple stages of deterioration-improvement evolution.

The flight operation risk is equal to the occurrence probability multiplied by the severity of the consequences. Flight operation risks include many types, forms, and numbers, and they frequently change with conditions. In the face of this complex system, through principle analysis, the risk formation mechanism research, and the spreading process, a scientific risk management and control method can be constructed. Based on the risk management technology, an informative and automated management control system can be developed and applied. The overall safety level of flight operations will be effectively improved. To analyze and study the flight operations risk propagation and then effectively control flight safety based on the complex network theory, 29 terminal factors were selected as network nodes according to the Civil Aviation Administration’s advisory notice, initially including the flight cabin crew, civil aviation aircraft, and operating environment. Civil aviation safety monitoring records from 2009 to 2014 were counted, and an undirected network was constructed based on node relationships. The relationships and occurrence probability between the nodes were counted, and a directed and weighted network was constructed. The concepts of improved infection rate and improved recovery rate were introduced, and an improved susceptible-infected-recovered (SIR) model suitable for flight operation risks was proposed. Finally, the initial infection range was clearly defined, and a multi-parameter control method was adopted. For directed networks, large-scale propagation and control simulations were calculated. The results indicate that the average shortest path of the directed network was 1.788, which belonged to the small-world network. The directed network infection node decreased to 37.4% with conventional control measures. After controlling top three or four nodes of the entry degree value sequence, the infected nodes peak drop rate was the biggest, as high as 50.6%/58.1%, the risk spread in the network was significantly suppressed. The results confirm that controlling nodes based on the entry degree value is the most effective method to suppress risk propagation in the directed and weighted network.

ObjectivesDue to the aging and illegal operation of crane equipment during hoisting operations on offshore platforms, dropped object accidents are the most prevalent type of accident, of which the dropping of slender rod-like objects such as drill collars and casings is the most common. Due to the small contact area and high velocity, the failure of the partial-plate structure is often caused, which requires attention.MethodsThis paper studies the specific deformation mechanism of a deck under the impact of dropped slender rods at different impact angles while considering the influence of the impact angle on damage to the deck. A new deformation model is proposed for decks subject to impact loads at different impact angles. Based on this new deformation model, a prediction method which considers the influence of the impact angle is obtained on the basis of the plastic mechanics theory.ResultsThe results show that a small impact angle will cause great structural damage and deformation, as well as high structural energy absorption. According to the structural response, the impact angle can be divided into four angle intervals. The energy absorption curves obtained from the analytical method and simulation are similar in value and change trend.Conclusions When a rod-like structure hits a deck at a certain angle, the shape of the plastic deformation area of the deck changes with the depth of the collision. The analytical results of the deformation characteristics of the deck at each stage can provide valuable references for the preliminary structural design and assessment of the crashworthiness of the deck structures of offshore platforms.

In this study, ultra-high-strength DH steels with different phase compositions were designed, their tensile strengths were greater than 1300 MPa, and the multiphase microstructures contained ferrite, martensite, retained austenite, and small amounts of carbides. The effects of different phase compositions on the mechanical properties and strain hardening behaviors of the ultra-high-strength DH steels were compared, and the mechanism of the retained austenite in the ultra-high-strength DH steels was comprehensively studied. The results show that with the increase in the volume fraction of martensite and retained austenite and decrease in the ferrite volume fraction, the yield strength and tensile strength increase, whereas, the elongation rate first increase and then decrease. The decrease in the soft-phase ferrite volume fraction and increase in the volume fraction of the hard martensite phase led to an increase in yield strength and tensile strength. Compared with tempered martensite, quenched martensite could improve the strength more significantly. The retained austenite transformed in the tensile process was the main cause of the change in elongation. The remarkable banded structure in the microstructure will cause a significant decrease in elongation after necking. The analysis of the strain hardening behavior show that the strain hardening rate decrease with the increase in the true strain. When the true strain was greater than 2%, the strain hardening rate of the steels followed the order: DH1 > DH2 > DH3; this trend was mainly influenced by the ferrite volume fraction. The strain hardening rate of DH2 was higher than those of DH1 and DH3 when the true strain was greater than 5.73%, which was mainly related to the more significant transformation-induced plasticity (TRIP) effect in the DH2. In addition to the retained austenite volume fraction, the carbon content in the retained austenite also had a significant effect on the TRIP effect. The high proportion of the hard-phase martensite, appropriate proportion of the soft-ductile-phase ferrite, and retained austenite contributed to the DH2 steel having the greatest tensile strength and elongation (13.17 GPa·%); moreover, the yield strength was 880 MPa, tensile strength was 1497 MPa, uniform elongation was 6.71%, total elongation was 8.8%, elongation after necking was 2.09%, and yield ratio was 0.59.

There are a large number of earthquake networks under the management of cities and counties，which have made historical contributions to reducing earthquake disasters and promoting the development of earthquake prevention and disaster reduction. In recent years，the development of earthquake networks managed by cities and counties lags behind the development level of the same industry，exposing problems such as unclear positioning，low efficiency and cognitive deviation. Taking Yangzhou Earthquake Networks Center as an example，the advantages and disadvantages before and after the institutional reform in 2019 are summarized and compared. The objectives and tasks of the modernization development of earthquake prevention and disaster reduction are combined. In order to promote the development of work，this paper puts forward suggestions from four aspects：self-orientation，work implementation，coordination of multiple relationships，scientific understanding of reform and development.

Human brain bank is the foundation for neurology and neuroscience, which provides research materials for medical scientists to explore what happen in human brains. Through voluntary postmortem brain tissue donation, brain bank collects, classifies, stores and distributes brain tissue samples for researchers with appropriate research proposals, so as to facilitate researchers to conduct human brain research. History showed that the act of brain only autopsy distinguished neurology as a distinct discipline. The emerges of brain banking accompanied with the advances of neurology and neuroscience. It facilitates the development of neurology from neuropathological examination feedback about the clinical presentations of the brain donor, plays an important role in the definition of novel neurological diseases, and also makes an extraordinary contribution to the disease mechanisms and novel therapeutic discoveries. This manuscript elaborated the history, current situation, and the impacts of human brain banking on current neurology. Furthermore, we discussed about the opportunities and challenges of brain banking in China. DOI:10.3969/j.issn.1672⁃6731.2020.10.012