Cognitive interference decision method for air defense missile fuze based on reinforcement learning

To solve the problem of the low interference success rate of air defense missile radio fuzes due to the unified interference form of the traditional fuze interference system,an interference decision method based Q-learning algorithm is proposed.First,dividing the distance between the missile and the target into multiple states to increase the quantity of state spaces.Second,a multidimensional motion space is utilized,and the search range of which changes with the distance of the projectile,to select parameters and minimize the amount of ineffective interference parameters.The interference effect is determined by detecting whether the fuze signal disappears.Finally,a weighted reward function is used to determine the reward value based on the range state,output power,and parameter quantity information of the interference form.The effectiveness of the proposed method in selecting the range of motion space parameters and designing the discrimination degree of the reward function has been verified through offline experiments involving full-range missile rendezvous.The optimal interference form for each distance state has been obtained.Compared with the single-interference decision method,the proposed decision method can effectively improve the success rate of interference.

Reachability-Based Confidence-Aware Probabilistic Collision Detection in Highway Driving

Risk assessment is a crucial component of collision warning and avoidance systems for intelligent vehicles.Reachability-based formal approaches have been developed to ensure driving safety to accurately detect potential vehicle collisions.However,they suffer from over-conservatism,potentially resulting in false–positive risk events in complicated real-world applications.In this paper,we combine two reachability analysis techniques,a backward reachable set(BRS)and a stochastic forward reachable set(FRS),and propose an integrated probabilistic collision–detection framework for highway driving.Within this framework,we can first use a BRS to formally check whether a two-vehicle interaction is safe;otherwise,a prediction-based stochastic FRS is employed to estimate the collision probability at each future time step.Thus,the framework can not only identify non-risky events with guaranteed safety but also provide accurate collision risk estimation in safety-critical events.To construct the stochastic FRS,we develop a neural network-based acceleration model for surrounding vehicles and further incorporate a confidence-aware dynamic belief to improve the prediction accuracy.Extensive experiments were conducted to validate the performance of the acceleration prediction model based on naturalistic highway driving data.The efficiency and effectiveness of the framework with infused confidence beliefs were tested in both naturalistic and simulated highway scenarios.The proposed risk assessment framework is promising for real-world applications.

Underdetermined direction of arrival estimation with nonuniform linear motion sampling based on a small unmanned aerial vehicle platform

Uniform linear array(ULA)radars are widely used in the collision-avoidance radar systems of small unmanned aerial vehicles(UAVs).In practice,a ULA's multi-target direction of arrival(DOA)estimation performance suffers from significant performance degradation owing to the limited number of physical elements.To improve the underdetermined DOA estimation performance of a ULA radar mounted on a small UAV platform,we propose a nonuniform linear motion sampling underdetermined DOA estimation method.Using the motion of the UAV platform,the echo signal is sampled at different positions.Then,according to the concept of difference co-array,a virtual ULA with multiple array elements and a large aperture is synthesized to increase the degrees of freedom(DOFs).Through position analysis of the original and motion arrays,we propose a nonuniform linear motion sampling method based on ULA for determining the optimal DOFs.Under the condition of no increase in the aperture of the physical array,the proposed method obtains a high DOF with fewer sampling runs and greatly improves the underdetermined DOA estimation performance of ULA.The results of numerical simulations conducted herein verify the superior performance of the proposed method.

Target layer state estimation in multi-layer complex dynamical networks considering nonlinear node dynamics

In many engineering networks, only a part of target state variables are required to be estimated.On the other hand,multi-layer complex network exists widely in practical situations.In this paper, the state estimation of target state variables in multi-layer complex dynamical networks with nonlinear node dynamics is studied.A suitable functional state observer is constructed with the limited measurement.The parameters of the designed functional observer are obtained from the algebraic method and the stability of the functional observer is proven by the Lyapunov theorem.Some necessary conditions that need to be satisfied for the design of the functional state observer are obtained.Different from previous studies, in the multi-layer complex dynamical network with nonlinear node dynamics, the proposed method can estimate the state of target variables on some layers directly instead of estimating all the individual states.Thus, it can greatly reduce the placement of observers and computational cost.Numerical simulations with the three-layer complex dynamical network composed of three-dimensional nonlinear dynamical nodes are developed to verify the effectiveness of the method.

Genomic analysis provides insights into the westward expansion of domesticated peaches in China

Peach, an economically important model plant of the Rosaceae family, has been domesticated and cultivated in China for approximately5 000 years. The Hexi Corridor, an important corridor connecting east-central China and the Tarim Basin, is the starting point of the Silk Road that links China and the Eurasian region. As a globally distributed fruit tree, the spread of peach was accomplished through historical trade routes in the Hexi Corridor and the Tarim Basin. However, knowledge of peach genetic diversity in these regions remains limited. In this study,we examined the relationships and the spread history of domesticated peaches through sequencing and genomic analysis of 161 peach accessions collected from Northwest China, including 43 from the Hexi Corridor and 104 from the Tarim Basin. The results indicate that peach landraces in the Hexi Corridor and the Tarim Basin are derivatives of peaches from the east and south of China (ESC). Notably, the genetic diversity of accessions from both the Hexi Corridor and the Tarim Basin was lower than that of ESC accessions. Reduction of diversity (ROD) and linkage disequilibrium (LD) analyses detected a genetic bottleneck in peaches from these regions. Additionally, these peaches have undergone varying degrees of selection from natural environment. Moreover, genes responsive to biotic and abiotic stresses were under selection, which could be the result of the climate change of Northwest China after the Last Glacial Maximum (LGM). Our findings provide a better understanding of the genetic basis of peach migration in Northwest China. Furthermore, this study expands the available genomic data for peaches and provides critical information for future peach breeding programs.

Peculiarity of transcriptional and H3K27me3 dynamics during peach bud dormancy

Bud dormancy facilitates the survival of meristems under harsh environmental conditions.To elucidate how molecular responses to chilling accumulation controlling dormancy in peach buds,chromatin immunoprecipitation sequencing to identify the H3K27me3 modifications and RNA sequencing of two peach cultivars with pronounced differences in chilling requirement were carried out,the results showed that genes associated with abscisic acid and gibberellic acid signal pathways play key roles in dormancy regulation.The results demonstrated that peach flower bud differentiation occurred continuously in both cultivars during chilling accumulation,which was correlated with the transcript abundance of key genes involved in phytohormone metabolism and flower bud development under adverse conditions.The more increased strength in high chillingrequirement cultivar along with the chilling accumulation at the genome-wide level.The function of the dormancy-associated MADS-box gene PpDAM6 was identified,which is involved in leaf bud break in peach and flower development in transgenic Nicotiana tabacum(NC89).In addition,PpDAM6 was positively regulated by PpCBF,and the genes of putative dormancy-related and associated with metabolic pathways were proposed.Taken together,these results constituted a theoretical basis for elucidating the regulation of peach bud dormancy transition.

Formation mechanisms and resource potential of carbonate geothermal reservoirs in the Beijing-Tianjin-Hebei plain

Investigating the formation mechanisms of carbonate geothermal reservoirs is of theoretical and practical significance for summarizing the formation pattern of geothermal resources and further guiding their effective exploitation.The Beijing-Tianjin-Hebei Plain(BTHP),predominantly located within the Jizhong Depression and Cangxian Uplift in the Bohai Bay Basin,serves as the primary region for geothermal exploitation and utilization in China.More than 1500 geothermal wells have been drilled therein,with water temperature at the wellhead ranging from 55 to 110°C,single-well flow rate ranging between 80 and 120 m^(3)/h,and cumulative heating area exceeding 100×10^(6)m^(3).However,the exploration and research in the region remain limited overall.As per the previous geothermal and petroleum exploration results and the latest geothermal drilling data,this study comprehensively evaluated the geothermal resources of karst geothermal reservoirs.The results show that two suites of carbonate karst reservoirs,namely the Jxw Formation and the Ordovician strata,have primarily developed in the BTHP,and their formation and evolution can be divided into four stages:the Mesoproterozoic-Early Paleozoic stage with carbonate sedimentation and the development of interlayer karst,the Late Paleozoic stage with the development of direct sedimentary cover,the Mesozoic stage with compressional uplifting and development of buried hill karst,and the Cenozoic stage with regional cover deposition and the modification and finalization of karst geothermal reservoirs.Accordingly,the porosity evolution history of the geothermal reservoirs is composed of three stages,namely a significant decrease followed by a minor increase,a gradual decline,and then a small fluctuation from increase to decrease before slowly rising again.The karstification in geothermal reservoirs can be summarized into quasi-syngenetic karstification,epigenetic karstification,and burial karstification,which can be subdivided into seven subcategories.The carbonate geothermal reservoirs in the study area boast total geothermal resources of 53.821×10^(9)GJ,or 184.155×10^(9)t of standard coal equivalent(tce),and the annual exploitable geothermal resources in the urban area can heat an area of(400‒500)×10^(6)m^(3),indicating great potential of geothermal exploitation.

Laser-induced breakdown spectroscopy as a method for millimeter-scale inspection of surface flatness

A non-contact method for millimeter-scale inspection of material surface flatness via Laser-Induced Breakdown Spectroscopy(LIBS)is investigated experimentally.The experiment is performed using a planished surface of an alloy steel sample to simulate its various flatness,ranging from 0 to 4.4 mm,by adjusting the laser focal plane to the surface distance with a step length of 0.2 mm.It is found that LIBS measurements are successful in inspecting the flatness differences among these simulated cases,implying that the method investigated here is feasible.It is also found that,for achieving the inspection of surface flatness within such a wide range,when univariate analysis is applied,a piecewise calibration model must be constructed.This is due to the complex dependence of plasma formation conditions on the surface flatness,which inevitably complicates the inspection procedure.To solve the problem,a multivariate analysis with the help of Back-Propagation Neural Network(BPNN)algorithms is applied to further construct the calibration model.By detailed analysis of the model performance,we demonstrate that a unified calibration model can be well established based on BPNN algorithms for unambiguous millimeter-scale range inspection of surface flatness with a resolution of about 0.2 mm.

Malfunction Diagnosis of the GTCC System under All Operating Conditions Based on Exergy Analysis

After long-term operation,the performance of components in the GTCC system deteriorates and requires timely maintenance.Due to the inability to directly measure the degree of component malfunction,it is necessary to use advanced exergy analysis diagnosis methods to characterize the components’health condition(degree of malfunction)through operation data of the GTCC system.The dissipative temperature is used to describe the degree of malfunction of different components in the GTCC system,and an advanced exergy analysis diagnostic method is used to establish a database of overall operating condition component malfunctions in theGTCC system.Ebsilon software is used to simulate the critical parameters of the malfunctions of the GTCC system components and to obtain the changes in the dissipative temperature of different components.Meanwhile,the fuel consumption and economic changes of the GTCC system on a characteristic power supply day under health and malfunction conditions are analyzed.Finally,the effects of maintenance costs,electricity,and gas prices on maintenance expenses and profits are analyzed.The results show that the GTCC system maintenance profit is 6.07$/MWh,while the GTCC system maintenance expense is 5.83$/MWh.Compared with the planned maintenancemode,the malfunction maintenance mode saves 0.24$/MWh.Simultaneously,the maintenance coefficient of GTCC should be adjusted under different malfunctions to obtain a more accurate maintenance period.

Atomic layer deposition of thin films:from a chemistry perspective

Atomic layer deposition(ALD)has become an indispensable thin-film technology in the contemporary microelectronics industry.The unique self-limited layer-by-layer growth feature of ALD has outstood this technology to deposit highly uniform conformal pinhole-free thin films with angstrom-level thickness control,particularly on 3D topologies.Over the years,the ALD technology has enabled not only the successful downscaling of the microelectronic devices but also numerous novel 3D device structures.As ALD is essentially a variant of chemical vapor deposition,a comprehensive understanding of the involved chemistry is of crucial importance to further develop and utilize this technology.To this end,we,in this review,focus on the surface chemistry and precursor chemistry aspects of ALD.We first review the surface chemistry of the gas–solid ALD reactions and elaborately discuss the associated mechanisms for the film growth;then,we review the ALD precursor chemistry by comparatively discussing the precursors that have been commonly used in the ALD processes;and finally,we selectively present a few newly-emerged applications of ALD in microelectronics,followed by our perspective on the future of the ALD technology.

PtrDJ1C,an atypical member of the DJ-1 superfamily,is essential for early chloroplast development and lignin deposition in poplar

The nuclear-encoded factors and the photosynthetic apparatus have been studied extensively during chloroplast biogenesis.However,many questions regarding these processes remain unanswered,particularly in perennial woody plants.As a model material of woody plants,poplar not only has very significant value of research,but also possesses economic and ecological properties.This study reports the Populus trichocarpa DJ-1C(PtrDJ1C)factor,encoded by a nuclear gene,and a member of the DJ-1 superfamily.PtrDJ1C knock-out with the CRISPR/Cas9 system resulted in different albino phenotypes.Chlorophyll fluorescence and immunoblot analyses showed that the levels of photosynthetic complex proteins decreased significantly.Moreover,the transcript level of plastid-encoded RNA polymerase-dependent genes and the splicing efficiency of several introns were affected in the mutant line.Furthermore,rRNA accumulation was abnormal,leading to developmental defects in chloroplasts and affecting lignin accumulation.We concluded that the PtrDJ1C protein is essential for early chloroplast development and lignin deposition in poplar.

Material manufacturing from atomic layer

Atomic scale engineering of materials and interfaces has become increasingly important in material manufacturing.Atomic layer deposition(ALD)is a technology that can offer many unique properties to achieve atomic-scale material manufacturing controllability.Herein,we discuss this ALD technology for its applications,attributes,technology status and challenges.We envision that the ALD technology will continue making significant contributions to various industries and technologies in the coming years.

转炉渣对煤粉导热系数的影响研究

利用稳态球体法测量添加转炉渣的高炉喷吹煤粉的导热系数,考察温度和添加剂的添加量对煤粉导热系数的影响。结果表明,添加微量的转炉渣(添加量0.5%)即可使煤粉的导热系数增加13.16%;随着转炉渣添加量从0.5%增大到4%,煤粉的导热系数逐渐降低,且导热系数随温度的变化程度逐渐减弱。

MiR156 regulates anthocyanin biosynthesis through SPL targets and other microRNAs in poplar

Anthocyanins biosynthesized from the flavonoid pathway are types of pigments that are involved in the protection of poplar from biotic and abiotic stresses.Previous researchers studying anthocyanin-related transcription factors and structural genes in poplar have made significant discoveries.However,little is known about the regulatory role of microRNAs in anthocyanin biosynthesis in poplar.Here,we overexpressed miR156 in poplar to study the comprehensive effects of the miR156-SPL module on the biosynthesis of anthocyanins.Small RNA sequencing analysis revealed 228 microRNAs differentially expressed in transgenic poplar plants with dramatically increased miR156 levels.Furthermore,integrated microRNAomic and transcriptomic analysis suggested that two microRNAs,miR160h,and miR858,have the potential to affect anthocyanin accumulation in poplar by regulating auxin response factors and MYB transcription factors,respectively.Additionally,the accumulation of miR160h and miR858 displayed a positive correlation with miR156 levels,suggesting a possible interaction between the miR156-SPL module and these microRNAs in poplar.Last,metabolomics analysis revealed that the levels of anthocyanins,flavones,and flavonols were substantially elevated in transgenic poplar plants overexpressing miR156 compared with the wild type,whereas the total lignin content was reduced in the transgenic plants.Taken together,our results indicate that miR156 can fine tune the anthocyanin biosynthetic pathway via multiple factors,including microRNAs,transcription factors,and the levels of structural genes,in poplar.This provides additional clues for understanding the complex regulatory network of anthocyanin biosynthesis in woody plants.

高流速辉光放电质谱法检测镍基高温合金中痕量元素及其深度分布

为了制造效率更高,输出功率更大,同时散热更少的飞机引擎,需要燃料的燃烧温度也越来越高,因此航空发动机的生产商和涡轮发动机的制造者对材料和部件提出了新的要求。在较高的温度时,为了维持材料的机械性能和提高合金部件的控制能力,需要继续改进原有的高温合金或者开发新一代高温合金,同时制造者也在建立更加严格的规格界限和质量控制规程。本文主要描述具有高流速离子源的辉光放电质谱仪,这种仪器的分析速度快,灵敏度高,非常适合于高温合金的分析。仪器除了可以做搜索分析和基材的杂质元素含量的检测之外,其直接进样的方法可以更好地检测出各种元素在产品高温受热之后的分布情况,以及痕量元素在保护层和界面的纵向分布。

Robust and high-sensitivity thermal probing at the nanoscale based on resonance Raman ratio (R3)

Raman spectroscopy-based temperature sensing usually tracks the change of Raman wavenumber,linewidth and intensity,and has found very broad applications in characterizing the energy and charge transport in nanomaterials over the last decade.The temperature coefficients of these Raman properties are highly material-dependent,and are subjected to local optical scattering influence.As a result,Raman-based temperature sensing usually suffers quite large uncertainties and has low sensitivity.Here,a novel method based on dual resonance Raman phenomenon is developed to precisely measure the absolute temperature rise of nanomaterial(nm WS_(2) film in this work)from 170 to 470 K.A 532 nm laser(2.33 eV photon energy)is used to conduct the Raman experiment.Its photon energy is very close to the excitonic transition energy of WS_(2) at temperatures close to room temperature.A parameter,termed resonance Raman ratio(R3)Ω=I_(A1g)/IE_(2g) is introduced to combine the temperature effects on resonance Raman scattering for the A_(1g) and E_(2g) modes.Ω has a change of more than two orders of magnitude from 177 to 477 K,and such change is independent of film thickness and local optical scattering.It is shown that when Ω is varied by 1%,the temperature probing sensitivity is 0.42 K and 1.16 K at low and high temperatures,respectively.Based on Ω,the in-plane thermal conductivity(k)of a∼25 nm-thick suspended WS_(2) film is measured using our energy transport state-resolved Raman(ET-Raman).k is found decreasing from 50.0 to 20.0 Wm^(−1) K^(−1) when temperature increases from 170 to 470 K.This agrees with previous experimental and theoretical results and the measurement data using our FET-Raman.The R3 technique provides a very robust and high-sensitivity method for temperature probing of nanomaterials and will have broad applications in nanoscale thermal transport characterization,non-destructive evaluation,and manufacturing monitoring.

茶树油制剂(颗粒剂)对保育猪生长性能的影响

试验旨在探究茶树油饲料添加剂(颗粒型)对保育猪生长性能的影响。试验动物选取小保育猪50头和大保育猪36头,小保育猪分为5组,每组10头,对照组饲喂基础饲料,试验组饲喂基础饲料中分别添加50 mg/kg、100 mg/kg、200 mg/kg、400 mg/kg茶树油的试验饲料。大保育猪分为6组,每组6头,对照组饲喂基础饲料,试验组饲喂基础饲料中分别添加500 mg/kg、1000 mg/kg、2000 mg/kg、4000 mg/kg、6000 mg/kg茶树油的试验饲料,试验期为60 d。结果表明,在小保育阶段,添加50 mg/kg茶树油饲料添加剂组在增重方面显著高于对照组(P<0.05);在大保育阶段,添加500 mg/kg茶树油添加剂组的试验组猪只增重最高,料重比最低;但是在大保育猪,添加茶树油添加剂的量达到6000 mg/kg时,料重比最高,并且显著低于对照组(P<0.05),说明在保育猪的不同阶段添加适量的茶树油饲料添加剂,可提高猪只的生长性能,降低料重比。

Improving the incorporation of indium component for InGaN-based green LED through inserting photonic crystalline in the GaN layer

We report on the effect of inserted photonic crystalline(Ph-C) in the GaN epitaxial layer on the incorporation of the indium component for the InGaN-based green LED. The adoption of Ph-C in the GaN layer shifted the Raman peak value of E2mode of GaN to lower frequency and resulted in a tensive stress relief. The stress relief can be attributed to strained lattices restoring in the matrix of Ph-C and the GaN pseudo-epitaxy over the air-void of the Ph-C. Moreover, the HRXRD rocking curves and AFM results show that the insertion of Ph-C also improves the crystal quality. With the inserted Ph-C, the indium component in the multiple quantum wells of the green LED(Ph-C LED) was enhanced. This resulted in a 6-nm red-shift of the peak wavelength. Furthermore, the LOP of the Ph-C LED was enhanced by 10.65% under an injection current of 20 mA.

含大位阻基团苯氧亚胺锆催化剂的合成及在制备UHMWPE中的应用

合成了酚氧基邻位上含有大位阻基团的双[(N-3,5-二枯基亚水杨醛)-2’-甲基环己胺]二氯化锆催化剂(Cat),并将其应用于乙烯均聚制备超高分子量聚乙烯(UHMWPE)。研究了以甲苯为溶剂,不同助催化剂、n(Al)/n(Zr)、聚合时间、聚合温度条件下,对Cat催化乙烯的聚合活性、UHMWPE相对分子质量的影响。结果表明,Cat在以甲基铝氧烷(MAO)或烷基铝为助催化剂,n(Al)/n(Zr)=50000,聚合时间为2h,聚合温度为50℃的条件下可高效催化乙烯聚合获得UHMWPE,催化活性大于200×10~6 g PE/mol Zr;尤其在三甲基铝(TMA)助催化剂的存在下,可获得黏均相对分子质量达到8×10~6的UHMWPE。

Common molecular subtypes among Asian hepatocellular carcinoma and cholangiocarcinoma

Objective:Intrahepatic cholangiocarcinoma(ICC)and hepatocellular carcinoma(HCC)are clinically disparate primary liver cancers with etiological and biological heterogeneity.In Thailand,both cancer types represent the primary cause of cancer-related deaths and are a major public health concern.