Predict the evolution of mechanical property of Al-Li alloys in a marine environment

The ocean is one of the essential fields of national defense in the future,and more and more attention is paid to the lightweight research of Marine equipment and materials.This study it is to develop a Machine learning(ML)-based prediction method to study the evolution of the mechanical properties of Al-Li alloys in the marine environment.We obtained the mechanical properties of Al-Li alloy samples under uniaxial tensile deformation at different exposure times through Marine exposure experiments.We obtained the strain evolution by digital image correlation(DIC).The strain field images are voxelized using 2D-Convolutional Neural Networks(CNN)autoencoders as input data for Long Short-Term Memory(LSTM)neural networks.Then,the output data of LSTM neural networks combined with corrosion features were input into the Back Propagation(BP)neural network to predict the mechanical properties of Al-Li alloys.The main conclusions are as follows:1.The variation law of mechanical properties of2297-T8 in the Marine atmosphere is revealed.With the increase in outdoor exposure test time,the tensile elastic model of 2297-T8 changes slowly,within 10%,and the tensile yield stress changes significantly,with a maximum attenuation of 23.6%.2.The prediction model can predict the strain evolution and mechanical response simultaneously with an error of less than 5%.3.This study shows that a CNN/LSTM system based on machine learning can be built to capture the corrosion characteristics of Marine exposure experiments.The results show that the relationship between corrosion characteristics and mechanical response can be predicted without considering the microstructure evolution of metal materials.

Promotion of activation ability of N vacancies to N2 molecules on sulfur-doped graphitic carbon nitride with outstanding photocatalytic nitrogen fixation ability

Nitrogen vacancies and sulfur co-doped g-C3N4 with outstanding N2 photofixation ability was synthesized via dielectric barrier discharge plasma treatment. X-ray diffraction, ultraviolet–visible spectroscopy, N2 adsorption, scanning electron microscopy, X-ray photoelectron spectroscopy, photoluminescence spectroscopy, and temperature-programmed desorption were used to characterize the as-prepared catalyst. The results showed that plasma treatment cannot change the morphology of the as-prepared catalyst but introduces nitrogen vacancies and sulfur into g-C3N4 lattice simultaneously. The as-prepared co-doped g-C3N4 displays an ammonium ion production rate as high as 6.2 mg·L^-1·h^-1·gcat^-1, which is 2.3 and 25.8 times higher than that of individual N-vacancy-doped g-C3N4 and neat g-C3N4, respectively, as well as showing good catalytic stability. Experimental and density functional theory calculation results indicate that, compared with individual N vacancy doping, the introduction of sulfur can promote the activation ability of N vacancies to N2 molecules, leading to promoted N2 photofixation performance.

储层水敏系统评价方法与水敏机理研究

矿物晶层间距测量试验能准确分析水化膨胀的水敏矿物种类及矿物晶层间距变化程度；扫描电子显微镜不镀膜定点观察试验既能观察分析矿物的种类，又可以确定各种矿物分布的位置；孔喉半径测量试验测量水敏伤害前后孔喉半径分布，间接给出了水敏运移颗粒的半径范围和堵塞位置，以上3种主要的储层水敏微观测试评价方法，结合常用的岩心流动与物理膨胀2种宏观水敏测试评价方法，能精细分析引起水敏伤害机理、主要水敏矿物种类、伤害位置以及引起伤害的时间与程度，克服了单一方法无法精确研宄水敏原因的不足之处。应用系统水敏评价方法研宄S油田岩样，其结果表明该岩样产生水敏的机理主要是以运移的颗粒架桥堵塞孔喉为主，膨胀性黏土矿物水化膨胀造成孔隙半径缩小为辅。

γ-aminobutyric acid secreted from isletβ-cells modulates exocrine secretion in rat pancreas

AIM： To investigate the role of endogenous γ-aminobutyric acid （GABA） in pancreatic exocrine secretion. METHODS： The isolated, vascularly perfused rat pancreas was employed in this study to eliminate the possible influences of extrinsic nerves and hormones. Cholecystokinin （CCK; 10 pmol/L） was intra-arterially given to stimulate exocrine secretion of the pancreas. RESULTS： Glutamine, a major precursor of GABA, which was given intra-arterially at concentrations of 1, 4 and 10 mmol/L, dose-dependently elevated the CCK-stimulated secretions of fluid and amylase in the normal pancreas. Bicuculline （10 μmol/L）, a GABAA receptor antagonist, blocked the enhancing effect of glutamine （4 mmol/L） on the CCK-stimulated exocrine secretions. Glutamine, at concentrations of 1, 4 and 10 mmol/L, dose-dependently increased the GABA concentration in portal effluent of the normal pancreas. The effects of glutamine on the CCK-stimulated exocrine secretion as well as the GABA secretion were markedly reduced in the streptozotocintreated pancreas. CONCLUSION： GABA could be secreted from β-cells into the isletoacinar portal system after administration of glutainine, and could enhance the CCK-stimulated exocrine secretion through GABAA receptors. Thus, GABA in islet β-cells is a hormone modulating pancreatic exocrine secretion.

Trends in global warming and evolution of polymerase basic protein 2 family from influenza a virus

Both global warming and influenza trouble humans in varying ways, therefore it is important to study the trends in both global warming and evolution of influenza A virus, in particular, proteins from influenza A virus. Recently, we have conducted two studies along this line to determine the trends between global warming and polymerase acidic protein as well as matrix protein 2. Although these two studies reveal some interesting findings, many studies are still in need because at least there are ten different proteins in influenza A virus. In this study, we analyze the trends in global warming and evolution of polymerase basic protein 2 (PB2) from influenza A virus. The PB2 evolution from 1956 to 2008 was defined using the unpredictable portion of aminoacid pair. Then the trend in this evolution was compared with the trend in the global temperature, the temperature in north and south hemispheres, and the temperature in influenza A virus sampling site and species carrying influenza A virus. The results show the similar trends in global warming and in PB2 evolution, which are in good agreement with our previous studies in polymerase acidic protein and matrix protein 2 from influenza A virus.

Near-Range Large Field-of-View Three-Dimensional Photon-Counting Imaging with a Single-Pixel Si-Avalanche Photodiode

Large field-of-view（FoV） three-dimensional（3 D） photon-counting imaging is demonstrated with a single-pixel single-photon detector based on a Geiger-mode Si-avalanche photodiode. By removing the collecting lens（CL）before the detector, the FoV is expanded to ±10°. Thanks to the high detection efficiency, the signal-to-noise ratio of the imaging system is as high as 7.8 dB even without the CL when the average output laser pulse energy is about 0.45 pJ/pulse for imaging the targets at a distance of 5 m. A 3 D image overlaid with the reflectivity data is obtained according to the photon-counting time-of-flight measurement and the return photon intensity.

Application of random walk model to fit temperature in 46 gamma world cities from 1901 to 1998

Very recently, we have applied the random walk model to fit the global temperature anomaly, CRUTEM3. With encouraging results, we apply the random walk model to fit the temperature walk that is the conversion of recorded tem-perature and real recorded temperature in 46 gamma world cities from 1901 to 1998 in this study. The results show that the random walk model can fit both temperature walk and real recorded temperature although the fitted results from other climate models are unavailable for comparison in these 46 cities. Therefore, the random walk model can fit not only the global temperature anomaly, but also the real recorded temperatures in various cities around the world.

Prediction of mutation position, mutated amino acid and timing in hemagglutinins from North America H1 influenza A virus

This study was trying to predict the mutations in H1 hemagglutinins of influenza A virus from North America including the predictions of mu-tation position, the predictions of would-be-mutated amino acids and the predictions of time of occurrence of mutations. The results paved a possible way for accurate, precise and reliable prediction of mutation in proteins from influenza A virus.

Determination of inter- and intra-subtype/species varia-tions in polymerase acidic protein from influenza A virus using amino-acid pair predictability

The polymerase acidic protein is an important family of proteins from influenza A virus, which is classified as many different subtypes or spe-cies. Thus, an important question is if these classifications are numerically distinguishable with respect to the polymerase acidic protein. The amino-acid pair predictability was used to transfer 2432 polymerase acidic proteins into 2432 scalar data. The one-way ANOVA found these polymerase acidic proteins distinguish-able in terms of subtypes and species. However, the large residuals in ANOVA suggested a pos-sible large intra-subtype/species variation. Therefore, the inter- and intra-subtype/species variations were studied using the model II ANOVA. The results showed that the in-tra-subtype/species variations accounted most of variation, which was 100% in total for both inter- and intra- subtype/species variations. Our analysis threw lights on the issue of how to de-termine a wide variety of patterns of antigenic variation across space and time, and within and between subtypes as well as hosts.

Rock slope stability evaluation in static and seismic conditions for left bank of Jinsha River Bridge along Lijiang-Xamgyi'nyilha railway, China

Jinsha River Bridge is located along the Lijiang-Xamgyi＇nyilha railway on the southeastern Tibet plateau; it is an area with a high prevalence of earthquakes. The bridge abutments were designed to be constructed in river bank slopes, where rocks are controlled by two sets of joint planes that significantly influence the stability of the left bank slope. According to the engineering-geological conditions and the characteristics of discontinuities, strength properties of the rock mass were obtained based on Barton model and direct shear test. Numerical analyses were performed using FLAC3D software to examine the slope＇s response to seismic loading. Then in order to evaluate the damage trends of the rock mass under the different loading conditions, a calculation model based on the geological parameters and slope stability was simulated and analyzed using the discrete element numerical simulation program UDEC （Universal Dis- tinct Element Code）, and the effect of degradation of discontinuities on the slope stability was investigated. The results show that the destruction of rock mass under the gravity, bridge foundation, and seismic load are mainly concentrated within 30 m depth of slope, and the slope under loading may slide along joint planes. In addition, the dynamic analysis by amplification of the input loading indicates that instability occurs to the bank slope at a height of about 200 m, and rock blocks will fail under seismic load. Therefore, to prevent the slope from deformation under the engineering loading and strong earthquakes, the bridge foundation should be strengthened.

Descriptively probabilistic relationship between mutated primary structure of von Hippel-Lindau protein and its clinical outcome

In this study, we use the cross-impact analysis to build a descriptively probabilistic relationship between mutant von Hippel-Lindau protein and its clinical outcome after quantifying mutant von Hippel-Lindau proteins with the amino-acid distribution probability, then we use the Bayes-ian equation to determine the probability that the von Hippel-Lindau disease occurs under a mutation, and finally we attempt to distinguish the classifications of clinical outcomes as well as the endocrine and nonendocrine neoplasia induced by mutations of von Hippel-Lindau protein. The results show that a patient has 9/10 chance of being von Hippel-Lindau disease when a new mutation occurs in von Hippel- Lindau protein, the possible distinguishing of classifications of clinical outcomes using mod-eling, and the explanation of the endocrine and nonendocrine neoplasia in modeling view.

Selection of Influential Microfabric Properties of Anisotropic Amphibolite Rocks on Its Uniaxial Compressive Strength (UCS): A Comprehensive Statistical Study

Occasionally, in complex inherent characteristics of certain rocks, especially anisotropic rocks it may be difficult to measure the uniaxial compressive strength UCS. However, the use of empirical relationships to evaluate the UCS of rock can be more practical and economical. Consequently, this study carried out to predict UCS from microfabrics properties of banded amphibolite rocks using multiple regression analysis. Based on statistical results, rock microfabric parameters, which adequately represent the UCS of a given rock type have been selected. The results show that grain size, shape factor and quartz content have high significant correlation with UCS at 95% confidence level. From multiple regression model, approximately 84% of the variance of the UCS can be estimated by the linear combination of these three parameters. However, according to model performance criteria: correlation coefficient (R = 0.919), variance account for (VAF = 97%) and root mean square error (RMSE = 4.16) the study clearly indicates that the developed model is reliable to predict the UCS. Finally, this approach can be easily extended to the modeling of rock strength in the absence of adequate geological information or abundant data.

Uptake of Polycyclic Aromatic Hydrocarbons across Bacterial Membrane

Polycyclic aromatic hydrocarbons (PAHs) are important pollutants, whose biodegradation and bioremediation with microorganisms are the promising ways to clean environments and reduce their exposure to humans. Although the transportation of PAHs across bacterial membrane is the first step forwards their biodegradation, it receives less attention. In this mini-review, we explore which transport system for uptake of carbon sources can serve for uptake of PAHs in bacteria, and try to uncover some patterns in their transport mechanisms. Collectively, 1) the major carbohydrate transport system, PTS, is unlikely to take PAHs because PAHs lack a hydroxy group for phosphorylation but aromatic acids are good candidates;2) PAHs could probably go through H+ symporters, especially the low-molecular-weight PAHs, which are partially dissolvable in water;3) it is unlikely that PAHs can produce chemiosmotic ion gradients to go through uniporters;and 4) antiporters could serve as transporters to transport PAHs across bacterial membrane only after the metabolism of PAHs generates extra H+ inside cell. Accordingly, the basic mechanism for uptake of PAHs is whether they can donate H+ in order to generate an electrochemical proton gradient to go through symporters.

A Photon-Counting Full-Waveform Lidar

We present the results of using a photon-eounting full-waveform lidar to obtain detailed target information with high accuracy.The parameters of the waveforms(i.e.,vertical structure,peak position,peak amplitude,peak width and backscatter cross section)are derived with a high resolution limit of 31 mm to establish the vertical structure and scattering properties of targets,which contribute to the recognition and classification of various scatterers.The photon-counting full-waveform lidar has higher resolution than linear-mode full-waveform lidar,and it can obtain more specific target information compared to photon-counting discrete-point lidar,which can provide a potential alternative technique for tomographic surveying and mapping.

Classification,metallogenesis and exploration of silver deposits in Daxing’anling of Inner Mongolia and its adjacent areas

By the end of 2020,83 silver deposits(or ore occurrences),including four super-large-scale deposits,nine large-scale deposits,33 medium-scale deposits and 37 small-scale deposits or ore occurrences,have been proved.The amount of silver metal exceeds 86000 t with average grade of 100 g/t,which makes Daxing’anling region one of the the most important silver ore belt in China.However,the metallogenic characteristics and metallogenesis need to be clarified.The silver deposits in the study area are classified into three main types,which are magmatic hydrothermal vein type,continental volcano-subvolcanic type and skarn type,respectively.The supergiant deposits include the Shuangjianzishan deposit(silver metal amount of 15214 t with average grade of 138 g/t),the Baiyinchagandongshan deposit(silver metal amount of 9446 t with average grade of 187 g/t),the Huaobaote deposit(silver metal amount of 6852 t with average grade of 170 g/t),and the Fuxingtun deposit(silver metal amount of 5240 t with average grade of 196 g/t).The silver deposits are mainly distributed in the central and south of the Daxing’anling area,and mainly formed in the Yanshanian period.The silver polymetallic deposits in the Daxinganling area are significantly controlled by regional faults and the junction zone of volcanic rock basins and their margins.The north-east trending deep faults are the most important ore-controlling structures in this area.The distribution of silver polymetallic deposits along the main faults is obvious,and the intersection area of multiple groups of faults often form important mine catchments.The Permian is the most important ore-bearing formation in this area,but some important silver polymetallic deposits occur in Mesozoic volcanic basins or pre-Mesozoic strata.The magmatic rocks related to mineralization are mainly intermediate acidic or acidic intrusions,intermediate acidic lavas,pyroclastic rocks,and small intrusions of ultra-shallow or shallow facies of the Yanshanian Period.The mineralization element combination is mainly determined by the elemental geochemical background of surrounding rocks or source layers.In addition,the type of deposit,the distance from the mineralization center,and the degree of differentiation of ore-forming rock mass are also important influence factors.The article analyzes the prospecting prospects of each silver deposit type in the study area,discusses the relationship between mineralization center and deep prospecting,and proposes that porphyry silver deposits should be paid attention to.In the prospecting and exploration of silver deposits,comprehensive evaluation and multi-target prospecting need to be strengthened because silver can coexist or be associated with a variety of metals.

Total dose test with γ-ray for silicon single photon avalanche diodes

Gamma-ray(γ-ray)radiation for silicon single photon avalanche diodes(Si SPADs)is evaluated,with total dose of 100 krad(Si)and dose rate of 50 rad(Si)/s by using 60Co as theγ-ray radiation source.The breakdown voltage,photocurrent,and gain have no obvious change after the radiation.However,both the leakage current and dark count rate increase by about one order of magnitude above the values before the radiation.Temperature-dependent current-voltage measurement results indicate that the traps caused by radiation function as generation and recombination centers.Both leakage current and dark count rate can be almost recovered after annealing at 200℃for about 2 hours,which verifies the radiation damage mechanics.

Adaptation in polymerase basic protein 1 family from influenza A virus to climate change

Global climate changes affect the functioning of ecosystems, in particular host-pathogen interactions, with major consequences in health ecology, however, it is less addressed how the change in global temperature affects the protein family of influenza virus. In this study, we studied the adaptation of polymerase basic protein 1 (PB1) family from influenza A virus to temperature change. 3841 PB1 proteins sampled from 1956-2011 were quantified by the amino-acid pair predictability and then compared their general changes with the temperature changes (Had-CRUT3v and CRUTEM4v data sets) of corresponding years on a 5? by 5? grid-box basis. Also, point-to-point comparisons were conducted from 1956 to 1998 in all and different species. The results showed that both changes in the temperature and unpredictable portion of PB1 proteins had similar trends from 1956 to 2011, which provides the evidence of virus adaptation at protein level to climate change.

Fitting evolutionary process of matrix protein 2 family from influenza A virus using analytical solution of differential equation

The evolution of protein family is a process along the time course, thus any mathematical methods that can describe a process over time could be possible to describe an evolutionary process. In our previously concept-initiated study, we attempted to use the differential equation to describe the evolution of hemagglutinins from influenza A viruses, and to discuss various issues related to the building of differential equation. In this study, we attempted not only to use the differential equation to describe the evolution of matrix protein 2 family from influenza A virus, but also to use the analytical solution to fit its evolutionary process. The results showed that the fitting was possible and workable. The fitted model parameters provided a way to further determine the evolutionary dynamics and kinetics, a way to more precisely predict the time of occurrence of mutation, and a way to figure out the interaction between protein family and its environment.

Elaboration of Simplest Folding Structures in 2-Dimensional Lattice with Delta-Hemolysin and Its Variants in HP Model

Although the advanced 3-dimensional structure measurements provide more and more detailed structures in Protein Data Bank, the simplest 2-dimensional lattice model still looks meaningful because 2-dimensional structures play a complementary role with respect to 3-dimensional structures. In this study, the folding structures of delta-hemolysin and its six variants were studied at 2-dimensional lattice, and their amino acid contacts in folding structures were considered according to HP model with the aid of normalized amino acid hydrophobicity index. The results showed that: 1) either delta-hemolysin or each of its variants could find any of its folding structure in one eighth of 1,129,718,145,924 folding structures because of symmetry, which reduces the time required for folding, 2) the impact of pH on folding structures is varying and associated directly with the amino acid sequence itself, 3) the changes in folding structures of variants appeared different case by case, and 4) the assigning of hydrophobicity index to each amino acid was a way to distinguish folding structures at the same native state. This study can help to understand the structure of delta-hemolysin, and such an analysis can shed lights on NP-problem listed in millennium prize because the HP folding in lattice belongs to a sub-problem of NP-problem.

Building Quantitative Gene Regulatory Mechanism in Quorum Sensing in <i>Pseudomonas aeruginosa</i>Using Transcriptomic Data

A large amount of transcriptomic data provides opportunities 1) to verify the gene regulatory mechanism, which is usually obtained from a single experiment, at population level;2) to uncover the gene regulatory mechanism at population level;and 3) to build a quantitatively gene regulatory mechanism. One of the best studied regulatory mechanisms in bacteria is the quorum sensing (QS), which plays an important role in regulation of bacteria population behaviors such as antibiotic production, biofilm formation, bioluminescence, competence, conjugation, motility and sporulation. Pseudomonas aeruginosa is a Gram-negative bacterium causing diseases in plants, animals, humans, and its biofilm and drug-resistance become great concerns in clinics. P. aeruginosa has three QS systems including a specific one for Pseudomonas. In this study, the transcriptomic data of P. aeruginosa were combined from 104 publications and QS gene expressions were analyzed under different experimental conditions. The results demonstrate the quantitatively regulatory mechanisms of QS genes at population level including 1) to rank and group QS-related genes according to their activity;2) to quantitatively define the role of a single global regulator;3) to find out the probability that a global regulator impacts QS genes and the probability that a QS gene responds to global regulators;and 4) to search for overlapped genes under four types of experimental conditions. These results provide integrative information on understanding the regulation of QS genes at population level.