An experimental study exploring the influencing factors for ultrasonic-assisted extraction of flavonoid compounds from leaves of Amorpha fruticosa L.

In this paper,the ultrasonic-assisted extraction process of flavonoid compounds from leaves of Amorpha fruticosa is optimized.In single factor experiments,solid/liquid ratios,ultrasonic power,ethanol concentrations and extraction cycles were experimental factors.Box–Behnken central composite design and RSM analyzed the effects of the four factors on the yield of total flavonoids.The optimal extraction parameters were solid/liquid ratio 1:50 g/mL,ultrasonic power 316 W,ethanol concentration 50%,4 extraction cycles.In the optimized condition,the estimated value of the regression model was 66.6456 mg/g while the measured value was 66.4329 mg/g.

基于元路径属性融合的异质网络表示学习

针对信息网络的表示学习进行研究,提出了一种基于元路径信息融合的异质图神经网络(metapath attribute fusion graph neural network,MAFGNN),通过在异质网络中引入元路径之前将目标节点的邻居信息包括元路径信息融入到节点中,实现目标节点和邻居信息的融合。该方法首先将不同类型的节点属性特征进行维度转换便于后续的融合操作,通过计算目标节点和邻居节点权重值完成目标节点信息的融合操作。然后根据特定元路径对目标节点进行融合,最后在不同元路径间实现不同语义信息的融合操作。在多个异质信息数据集上进行实验表明,MAFGNN模型在处理异质网络节点嵌入方面相比于最先进的基准实验有最好的性能和更加准确的预测结果。

Mapping of QTLs Associated with Salt Tolerance of Maize Inbred Line at Seedling Stage

[ Objective] This study aimed to map quantitative tarit loci （QTLs） associated with salt tolerance of maize inbred line at seedling stage. [ Method! The recombinant inbred line （RIL） F7 including 171 plants were developed by single seed descent procedure from a combination, Huangzazsi × Mo17, and used to map QTLs associated with salt tolerance, based on the constructed genetic map of SSR markers. [ Resultl A linkage map consisting of 81 SSR markers loci from 10 chromosomes （ 1 428.3 cM in total length, with an average distance of 17.63 cM between two neighbouring loci） was constructed. Six QTI~ associated significantly with salt tolerance were detected at chromosomes 1,5 and 6. [ Conclusion] This study is extremely significant for better understanding sah tolerance-related genes, the genes＇ location and cloning, salt tolerance mechanism and the marker-assisted selection of salt tolerant maize.

Biological Characteristics and Research Status of Acetic Acid Bacteria for Fruit Vinegar Brewing

Fruit vinegar is a new beverage emerging in recent years because of its rich nutrition. At present, acetic acid bacteria are main strains used in the fruit vinegar production. Acetic acid bacteria are a general term for a class of bacteria that can oxidize ethanol to acetic acid. This paper mainly summarized the biological characteristics and research status of acetic acid bacteria for fruit vinegar brewing, in order to provide a theoretical basis for the selection of high-quality acetic acid bacteria for fruit vinegar brewing.

Eigenvalue analysis of planar linear multibody system under conservative force based on the transfer matrix method

The linear multibody system transfer matrix method(LMSTMM)provides a powerful tool for analyzing the vibration characteristics of a mechanical system.However,the original LMSTMM cannot resolve the eigenvalues of the systems with ideal hinges(i.e.,revolute hinge,sliding hinge,spherical hinge,cylindrical hinge,etc.)or bodies under conservative forces due to the lack of the corresponding transfer matrices.This paper enables the LMSTMM to solve the eigenvalues of the planar multibody systems with ideal hinges or rigid bodies under conservative forces.For a rigid body,the transfer matrix can now consider coupling terms between forces and kinematic state perturbations.Also,conservative forces that contribute to the eigenvalues can be considered.Meanwhile,ideal hinges are introduced to LMSTMM,which enables the treatment of eigenvalues of general multibody systems using LMSTMM.Finally,the comparative analysis with ADAMS software and analytical solutions verifies the effectiveness of the proposed approach in this paper.

复合菌系降解玉米秸秆过程中群落演替与秸秆降解的关系

【目的】为了获得木质素降解复合菌系LDC降解玉米秸秆的适宜条件,明确秸秆降解过程中可能发挥重要作用的功能微生物类群。【方法】以培养温度、pH、培养基装液量和接菌量等单因素试验结果为依据,采用响应面法优化复合菌系降解玉米秸秆的培养条件,利用Miseq高通量测序技术,分析不同降解时期复合菌系的群落结构变化规律。【结果】复合菌系对秸秆最佳降解条件为:培养温度32°C、初始pH为8.2、装液量为40%,接菌量为10%。此条件下木质素最大降解率为44.5%,相比未优化处理提高13.3%。在门水平上,变形菌门(Proteobacteria)、拟杆菌门(Bacteroidetes)和厚壁菌门(Firmicutes)是复合菌系LDC的优势菌门。在玉米秸秆降解过程中,降解初期的优势菌属为Proteiniphilum(11.9%)、 Sphaerochaeta(8.4%)、 Ruminofilibacter(8.4%)、 Pannonibacter(6.7%)、Pseudomonas(6.1%)和Rhizobium(5.7%);在降解高峰期时,Anaerocolumna(24.0%)、Caenispirillum(9.2%)和Thauera(7.0%)的丰度显著上升,分别是其在降解初期的16.5倍、 3.0倍和5.9倍,而Ruminofilibacter(10.9%)的丰度仍然很高且排在第二位。在降解末期的优势菌属为Ruminofilibacter(25.4%)、Pseudomonas (9.7%)、Sphaerochaeta (8.8%)、Caenispirillum (8.4%)、Pannonibacter (4.3%)、Thauera (4.0%)以及Desulfomicrobium (3.4%)。【结论】明确了玉米秸秆降解复合菌系的最佳培养条件以及在不同降解时期微生物群落结构变化规律,在玉米秸秆降解过程中发挥重要作用的微生物类群为Pseudomonas、Pannonibacter、Thauera、Ruminofilibacter和Anaerocolumna。

Characteristics of Diagenesis and Pore Evolution of Volcanic Reservoir: A Case Study of Junggar Basin, Northwest China

Unconventional volcanic reservoir is different from conventional reservoir in reservoir space,diagenesis,pore formation and evolution.The Carboniferous volcanic reservoir was selected in Junggar Basin,Northwest China because based on sediment/rock cores and outcrop data,diagenesis and pore evolution were studied by elemental measurements,thin section observations,and diagenetic analyses.These analyses shows that the reservoir lithology is predominantly intermediate-basic volcanic,and the reservoir storage space is composed mainly of secondary dissolved pores and fractures.The reservoir displays great heterogeneity,and has experienced a great variety of diagenetic alteration during various diagenetic stages including:(1)eruption fragmentation,crystallization differentiation and condensing consolidation at consolidated diagenetic stage;(2)metasomatic alteration,filling,weathering and leaching,dissolution by formation fluids and tectonism at the epigenetic modifications stage.The formation and evolutionary process of the pores is extremely complicated.The primary pores were formed during the consolidated diagenetic stage,and laid a foundation for the late development and alteration of effective reservoir.During the epigenetic modifications stage secondary reservoir storage space was developed via the formation of secondary pores and the development of fractures through weathering and leaching,dissolution by formation fluids and tectonism.

Vibration characteristics analysis of tank gun barrel with nonuniform cross-section

The firing accuracy of a tank gun is affected significantly by the flexural motion of the barrel.For the purpose of satisfying the requirement of efficiently and accurately dynamic analysis and optimization of the tank gun barrel to ensure it has good dynamic characteristics and firing accuracy,the high-fidelity dynamic model of a tank gun barrel is developed according to the transfer matrix method for multibody system which has features of high degree of stylization and high computational speed.The transfer matrix of the non-uniform Euler-Bernoulli beam(NU-EB beam)is deduced from governing differential equations of motion utilizing the differential transform method.The orthogonality of augmented eigenvectors for the NU-EB beam is proven which can be used for its exact dynamics response analysis using the modal method.In allusion to the tank gun barrel with non-uniform cross-section,the barrel is modeled as a combination of several uniform and non-uniform transverse vibrating Euler-Bernoulli beams.The overall transfer equation and matrix of the tank gun barrel are established according to the automatic deduction theorem of the overall transfer equation of multibody system.The present method is proven to be effective by comparing the computational results to those in published literatures.The vibration characteristics of a tank gun barrel with a non-uniform cross-section are analyzed accurately and are verified by the modal test.

Characteristics and formation of sinian(Ediacaran)carbonate karstic reservoirs in Dengying Formation in Sichuan Basin,China

The Gaoshiti-Moxi Gas Field has been discovered recently in the central part of Sichuan Basin,which might be the biggest gas field in China.In this gas field,a large amount of gas is from Neoproterozoic Sinian(Ediacaran)karstic carbonate rocks.The gas was originated from cracking of oil,and the oil source rocks are the Sinian and Cambrian strata.In this study,the characteristics of these carbonate reservoir rocks have been studied based on subsurface data and outcrop observation.The carbonate rocks are at the Sinian Dengying Formation,and the reservoir properties are controlled by sedimentary facies and diagenesis.The Dengying Formation is composed of algal mounds and grainstone build-ups,which were developed in a restricted platform setting from glacial period to interglacial period.Due to tectonic movement and eustatic cycle in Sichuan Basin during Neoproterozoic Era,five sedimentary cycles of transgression and regression have been developed in the Dengying Formation.According to the sedimentary facies and carbon-oxygen isotope variation,five sedimentary cycles have been recognized.Due to the penecontemporaneous dolomitization,together with hypergene karstification and late burial dissolution,the reservoir properties of the carbonates rocks have been improved greatly.

The effect of geometric layout of exit on escape mechanism of crowd

In dense crowd evacuation,especially in emergencies such as fires,the safe evacuation of large public facilities will face major challenges.At the same time,as cluster congestion tends to occur in the space where the flow rate drops sharply,the superposition of fire incidents and bottleneck areas can easily evolve into malignant disasters and crowd stampedes with serious harm and influence.In this paper,Massmotion based on social force model is used to carry out a numerical simulation on exit position and corner exit form to find out the mechanism and influence law of the slight architectural adjustment on the flow at bottleneck.The results show that the traditional middle exit design is not the best,and the evacuation efficiency of the corner exit is higher than that of the middle exit.Compared with other corner exits,the average time interval between two adjacent persons passing through the bottleneck under the 30°corner exit is the shortest,and the probability of outlet clogging drops the fastest,exceeding 18%of the slowest descending speed.At the 0°corner exit,the waiting time cost of pedestrians is high and the risk of evacuation is high.The outcomes of this work can provide reference for the structural design of the building and the safe evacuation of personnel,so as to improve the evacuation efficiency and safety of pedestrians in the building to some extent.

Research on the influence of building convex exit on crowd evacuation and its design optimization

Building exit has always been an emphasis of research in the field of evacuation.Existing studies on crowd flow characteristics at building evacuation bottlenecks usually focus on plane exit,but insufficient attention has been paid to the characteristics of crowd flow at the convex exit.Convex exit can be considered as such a structure like a double-bottleneck linked passage.This paper aims to study the influence of geometric structure characteristics of the convex exit on crowd evacuation and put forward the optimal design strategy of this structure,so as to improve the efficiency of evacuation in an emergency.Using social force model-based software,MassMotion,it is found that convex exit is indeed more efficient and safer than common plane exit in terms of evacuation time and pedestrians'congestion,especially when the desired speed is relatively higher,indicating that convex exits are more suitable for crowd evacuation in case of emergency.Four size-related parameters of convex exit are analyzed in detail,namely the width of the bottleneck at passage(W_(p)),the passage width(W),the passage length(L),and the exit width(W_(e)),to find out the optimum design of convex exit.The research shows that the optimal size ratio is that Wp:W:L:We equals 1.5:1.75:3.5:1,and as the overall magnification of building size and the number of pedestrians increases,the evacuation time gradually tends to a stable value,which indicates that this optimal ratio has good adaptability in size effect.Finally,based on the in-depth mechanism of pedestrian flow at the convex exit,three possible application scenarios are proposed to illustrate the feasible optimum design of the convex exit.The results of this study can provide new ideas for research on the structure of building exits.