Predicting triaxial compressive strength of high-temperature treated rock using machine learning techniques

The accurate prediction of the strength of rocks after high-temperature treatment is important for the safety maintenance of rock in deep underground engineering.Five machine learning(ML)techniques were adopted in this study,i.e.back propagation neural network(BPNN),AdaBoost-based classification and regression tree(AdaBoost-CART),support vector machine(SVM),K-nearest neighbor(KNN),and radial basis function neural network(RBFNN).A total of 351 data points with seven input parameters(i.e.diameter and height of specimen,density,temperature,confining pressure,crack damage stress and elastic modulus)and one output parameter(triaxial compressive strength)were utilized.The root mean square error(RMSE),mean absolute error(MAE)and correlation coefficient(R)were used to evaluate the prediction performance of the five ML models.The results demonstrated that the BPNN shows a better prediction performance than the other models with RMSE,MAE and R values on the testing dataset of 15.4 MPa,11.03 MPa and 0.9921,respectively.The results indicated that the ML techniques are effective for accurately predicting the triaxial compressive strength of rocks after different high-temperature treatments.

A New Exploration of Artificially Induced Spalted Wood of Two Fungi:Hypoxylon and Sistotrema

One strain of Hypoxylon sp.CXM-3 and one strain of Sistotrema brinkmannii CXM-4 were inoculated onto sterilized cherry,poplar,birch,and basswood sheets in a certain shape and incubated at constant temperature and humidity for 4,8,12,and 16 weeks,respectively,to analyze whether the grain pattern formed by the zone lines was consistent with the predetermined pattern.The results showed that the zone lines of CXM-3 of Hypoxylon were free,delicate,and soft,with brown lines and black staining,mostly accompanied by black and brown dots,facets,and clusters,while the zone lines of CXM-4 of Sistotrema brinkmannii grew along the predetermined grain,with strong lines and a clean surface.After inoculation and incubation at a constant temperature of 25℃±2℃ and humidity of 60%,Sistotrema brinkmannii CXM-4,on basswood veneer at 4-8 weeks and cherry veneer at 4-16 weeks,were able to develop zone lines following a predetermined grain.Artificially induced spalted wood can only maintain a large shape,which cannot guarantee that the pattern of large-scale production of spalted wood is exactly the same and cannot be accurate to the minute details.The artificial induction can thus result in the formation of a predetermined grain pattern of the mottled wood,thus enhancing the product value and artistic value of solid wood furniture and crafts.

赣南客家文化简述

客家是指客家民系、是客家人的简称,具有独特的客家方言,独特的文化民俗和情感心态。赣南是历史上客家人的重要集散地和当今客家人最大的聚居地。本文将从客家民俗和客家饮食等方面对进行赣南客家文化阐述,尤其是以九狮拜象、竹篙火龙节、赣南采茶戏等庆祝活动和荷包肉、鱼丝、艾米果等特色食物为代表进行分析。

五运六气理论的简释

五运六气理论是专门讨论天体运动、气候、生态、人体的内存联系的理论,也是中医基础理论的核心?经典文献及现有文献对五运六气理论的论述过于复杂,使得读者难以理解。本文通过摘抄经典文献并结合现有文献,将五运六气理论的概念、天干地支与五运六气的关系、五运六气在天干地支中的计算、五运六气在疾病防治中的应用进行简要的论述。

Carbon-Based Flexible and All-Solid-State Micro-supercapacitors Fabricated by Inkjet Printing with Enhanced Performance

By means of inkjet printing technique, flexible and all-solid-state micro-supercapacitors(MSCs) were fabricated with carbon-based hybrid ink composed of graphene oxide(GO,98.0vol.%) ink and commercial pen ink(2.0vol.%). A small amount of commercial pen ink was added to effectively reduce the agglomeration of theGO sheets during solvent evaporation and the following reduction processes in which the presence of graphite carbon nanoparticles served as nano-spacer to separate GO sheets. The printed device fabricated using the hybrid ink,combined with the binder-free microelectrodes and interdigital microelectrode configuration, exhibits nearly 780%enhancement in areal capacitance compared with that of pure GO ink. It also shows excellent flexibility and cycling stability with nearly 100% retention of the areal capacitance after 10,000 cycles. The all-solid-state device can be optionally connected in series or in parallel to meet the voltage and capacity requirements for a given application.This work demonstrates a promising future of the carbonbased hybrid ink for directly large-scale inkjet printing MSCs for disposable energy storage devices.

Predicting the strut forces of the steel supporting structure of deep excavation considering various factors by machine learning methods

The application of steel strut force servo systems in deep excavation engineering is not widespread,and there is a notable scarcity of in-situ measured datasets.This presents a significant research gap in the field.Addressing this,our study introduces a valuable dataset and application scenarios,serving as a reference point for future research.The main objective of this study is to use machine learning(ML)methods for accurately predicting strut forces in steel supporting structures,a crucial aspect for the safety and stability of deep excavation projects.We employed five different ML methods:radial basis function neural network(RBFNN),back propagation neural network(BPNN),K-Nearest Neighbor(KNN),support vector machine(SVM),and random forest(RF),utilizing a dataset of 2208 measured points.These points included one output parameter(strut forces)and seven input parameters(vertical position of strut,plane position of strut,time,temperature,unit weight,cohesion,and internal frictional angle).The effectiveness of these methods was assessed using root mean square error(RMSE),correlation coefficient(R),and mean absolute error(MAE).Our findings indicate that the BPNN method outperforms others,with RMSE,R,and MAE values of 72.1 kN,0.9931,and 57.4 kN,respectively,on the testing dataset.This study underscores the potential of ML methods in precisely predicting strut forces in deep excavation engineering,contributing to enhanced safety measures and project planning.

All-optical nanoscale thermometry with silicon carbide color centers

All-optical thermometry plays a crucial role in precision temperature measurement across diverse fields.Quantum defects in solids are one of the most promising sensors due to their excellent sensitivity,stability,and biocompatibility.Yet,it faces limitations,such as the microwave heating effect and the complexity of spectral analysis.Addressing these challenges,we introduce a novel approach to nanoscale optical thermometry using quantum defects in silicon carbide(SiC),a material compatible with complementary metal-oxide-semiconductor(CMOS)processes.This method leverages the intensity ratio between anti-Stokes and Stokes emissions from SiC color centers,overcoming the drawbacks of traditional techniques such as optically detected magnetic resonance(ODMR)and zero-phonon line(ZPL)analysis.Our technique provides a real-time,highly sensitive(1.06%K^(-1)),and diffraction-limited temperature sensing protocol,which potentially helps enhance thermal management in the future miniaturization of electronic components.

Tailoring interlayer spacing in MXene cathodes to boost the desalination performance of hybrid capacitive deionization systems

Capacitive deionization(CDI)is a promising technology to satisfy the global need for fresh water,since it can be both economical and sustainable.While two-dimensional transition metal carbides/nitrides(MXenes)exhibit great characteristics for use as CDI electrode materials,their tightly spaced layered structure renders intercalation inefficiency.In this study,the interlayer distance of MXenes is precisely modulated by inserting different quantity of one-dimensional bacterial fibers(BC),forming freestanding MXene/BC composite electrodes.Among the studied samples,MXene/BC-33%electrode with the interlayer spacing of 15.2Åcan achieve an optimized tradeoff among various desalination performance metrics and indicators.The salt adsorption capacity(SAC),the average salt adsorption rate(ASAR),the energy normalized adsorbed salt(ENAS),and the thermodynamic energy efficiency(TEE)of the MXene/BC-33%electrode are improved by 24%,46%,13%,and 66%respectively compared with those of pure MXene electrode.While the insertion of BC improves the ion diffusion pathways and facilitates the intercalation kinetics,the desalination performance decreases when the insertion amount of BC exceeds 40%.This is attributed to the overlarge resistance of the composite and the resulting increased energy consumption.This study reveals the desalination performance tradeoffs of MXene-based electrodes with different interlayer distances and also sheds light on the fundamental ion storage mechanisms of intercalation materials in a CDI desalination system.

Surface terminals reconstruction:The way to widen the output voltage of MXene-based aqueous symmetrical microsupercapacitors

The low anodic oxidation potential severely suppresses the output voltage(≤0.6 V)of MXene-based symmetrical aqueous microsupercapacitors(MSA-MSCs)employing acidic electrolytes.Herein,a surface terminals reconstruction mechanism on cathode of MSA-MSCs adopting aqueous neutral electrolyte(1 M Na_(2)SO_(4))is first revealed by systematical electrochemical experiments and in/ex-situ spectral analysis,which indicates that:the-O terminals on Ti3C2Tx flakes of cathode can combine with intercalated Na+cations during charging process to reconstruct into-ONa units to(i)inhibit the splitting reaction of adjacent water molecules,decreasing cathodic hydrogen evolution potential,more significantly,(ii)lower the potential of zero voltage(P0V)between the symmetrical electrodes to avoid anode oxidation,enabling full use of the unexploited potential range of cathode.Thus,the output voltage of the MSA-MSCs tremendously expanded from 0.6 V in acidic polyacrylamide(PAM)/1 M H_(2)SO_(4)hydrogel electrolyte to 1.5 V in neutral polyacrylamide/1 M Na2SO4 hydrogel electrolyte,boosting the corresponding areal energy density from 9.9 to 34.6μW·h·cm^(-2).The demonstrated deep insight on the surface terminals reconstruction mechanism for synchronously modulating the P0V between symmetrical electrodes and hydrogen evolution potential on cathode provides critical guidance for widening the cell voltage of MSA-MSCs with safer and more inexpensive neutral electrolytes.

Collaborative Diffusion Model of Information and Behavior in Social Networks

Information diffusion may lead to behaviors related to information content.This paper considers the co-existence of information and behavior diffusion in social networks.The state of users is divided into six categories,and the rules and model of collaborative diffusion of information and behavior are established.The influence of different parameters and conditions on the proportions of behavior diffusion nodes and information diffusion ones is analyzed experimentally.The results show that the proportion of nodes taking action in uniform networks is higher than that in non-uniform networks.Although users are more likely to take actions related to information content after spreading or knowing information,the results show that it has little influence on the proportion of users taking action.The proportion is mainly affected by the probability that users who do not take action become ones who take.The greater the probability,the less the proportion of nodes who know information.In addition,compared with choosing the same node as the initial information and behavior diffusion node,choosing different nodes is more beneficial to the diffusion of behaviors related to information content.

清肺渗湿汤对哮喘小鼠肺组织MMP-2、MMP-9、TIMP-1表达的影响

目的探究清肺渗湿汤对支气管哮喘小鼠肺组织MMP-2、MMP-9、金属蛋白酶组织抑制剂-1(TIMP-1)表达的影响。方法将50只BALB/C雄性小鼠按随机数字表法分为对照组、模型组、地塞米松组、清肺渗湿汤低剂量组、清肺渗湿汤高剂量组,每组10只。采用卵清蛋白激发法制备哮喘模型小鼠。造模成功后,地塞米松组灌胃地塞米松1.56 mg/kg,清肺渗湿汤低、高剂量组灌胃清肺渗湿汤14.235、28.470 g/kg,对照组、模型组灌胃等体积的0.9%氯化钠溶液。干预4周后,检测各组小鼠气道反应性(Penh值);HE染色观察肺组织病理学改变;ELISA检测肺泡灌洗液中IL-6、IL-1β、TNF-α水平;Western blot法检测肺组织中MMP-2、MMP-9、TIMP-1表达。结果与模型组比较,清肺渗湿汤各剂量组小鼠肺组织气管壁、肺泡壁损伤明显减轻。与模型组比较,清肺渗湿汤低、高剂量组小鼠Penh值降低(P<0.05),肺泡灌洗液中IL-6、IL-1β、TNF-α水平降低(P<0.05),肺组织MMP-9、MMP-2、TIMP-1表达降低(P<0.05),且具有一定的剂量依赖性。结论清肺渗湿汤可有效缓解哮喘模型小鼠气道炎症,减轻气道高反应性、改善肺功能,抑制气道重塑,其作用机制可能与下调MMP-2、MMP-9、TIMP-1表达有关。

Subseasonal Zonal Oscillation of the Western Pacific Subtropical High during Early Summer

This study examines the features and dynamical processes of subseasonal zonal oscillation of the western Pacific subtropical high （WPSH） during early summer, by performing a multivariate empirical orthogonal function （MV- EOF） analysis on daily winds and a diagnosis on potential vorticity （PV） at 500 hPa for the period 197%2016. The first MV-EOF mode is characterized by an anticyclonic anomaly occupying southeastern China to subtropical west-ern North Pacific regions. It has a period of 10-25 days and represents zonal shift of the WPSH. When the WPSH stretches more westward, the South Asian high （SAH） extends more eastward. Above-normal precipitation is ob- served over the Yangtze-Huaihe River （YHR） basin. Suppressed convection with anomalous descending motion is located over the subtropical western North Pacific. The relative zonal movement of the SAH and the WPSH helps to establish an anomalous local vertical circulation of ascending motion with upper-level divergence over the YHR basin and descending motion with upper-level convergence over the subtropical western Pacific. The above local ver-tical circulation provides a dynamic condition for persistent rainfall over the YHR basin. An enhanced southwest flow over the WPSH＇s western edge transports more moisture to eastem China, providing a necessary water vapor condition for the persistent rainfall over the YHR basin. A potential vorticity diagnosis reveals that anomalous diaba- tic heating is a main source for PV generation. The anomalous cooling over the subtropical western Pacific produces a local negative PV center at 500 hPa. The anomalous heating over the YHR basin generates a local positive PV cen-ter. The above south-north dipolar structure of PV anomaly along with the climatological southerly flow leads to northward advection of negative PV. These two processes are conducive to the WPSH＇s westward extension. The vertical advection process is unfavorable to the westward extension but contributes to the eastward retreat of the WPSH.

Effects of nanoparticle structural features on the light-matter interactions in nanocermet layers and cermet-based solar absorbers

Metallic nanoparticle(NP)/ceramic composite cermets present desirable broadband absorption of the solar spectrum and thus are the preferred material scheme for constructing cermet-based solar absorbers.However,the effects of fine nanoparticle structural features on the light-matter interactions in nanocermet layers and corresponding cermet-based solar absorbers are still not well clear until now.Herein,we report a systematical investigation on the effects of W(tungsten)nanoparticle sizes,its concentrations and configurations in an alumina matrix on the optical responses of WeAl_(2)O_(3) nanocermet layers and a solar absorber with double-cermet layers.It is found that to possess admirable light absorption features at high temperatures,it is better to maintain the fine particle size of less than 10 nm,isolated states and suitable separations between them for WeAl_(2)O_(3) nanocermets.Thus,the dominated intrinsic absorption of W NPs,their plasmonic excitation and coupling effects among each other all contribute significantly to the broadband optical performance of the cermet layers and the whole absorber.More importantly,this study demonstrates a valuable criterion for maintaining optical performances of nanocermet layers and cermet-based solar absorbers under heating and thus their thermal robustness.