期刊文献+
共找到2,474篇文章
< 1 2 124 >
每页显示 20 50 100
Phase spectrum estimation of the seismic wavelet based on a criterion function 被引量:4
1
作者 Yu Yongcai Wang Shangxu +1 位作者 Yuan Sanyi Qi Pengfei 《Petroleum Science》 SCIE CAS CSCD 2012年第2期170-181,共12页
Phase spectrum estimation of the seismic wavelet is an important issue in high-resolution seismic data processing and interpretation. On the basis of two patterns of constant-phase rotation and root transform for wave... Phase spectrum estimation of the seismic wavelet is an important issue in high-resolution seismic data processing and interpretation. On the basis of two patterns of constant-phase rotation and root transform for wavelet phase spectrum variation, we introduce six sparse criteria, including Lu’s improved kurtosis criterion, the parsimony criterion, exponential transform criterion, Sech criterion, Cauchy criterion, and the modified Cauchy criterion, to phase spectrum estimation of the seismic wavelet, obtaining an equivalent effect to the kurtosis criterion. Through numerical experiments, we find that when the reflectivity is not a sparse sequence, the estimated phase spectrum of the seismic wavelet based on the criterion function will deviate from the true value. In order to eliminate the influence of non-sparse reflectivity series in a single trace, we apply the method to the multi-trace seismogram, improving the accuracy of seismic wavelet phase spectrum estimation. 展开更多
关键词 Seismic wavelet phase spectrum criterion function SPARSE
原文传递
239Pu alpha spectrum analysis based on PIPS detector response function and variations with vacuum and distance 被引量:7
2
作者 Rui Shi Xian-Guo Tuo +3 位作者 Huai-Liang Li Jian-Bo Yang Yi Cheng Hong-Long Zheng 《Nuclear Science and Techniques》 SCIE CAS CSCD 2017年第1期20-26,共7页
Effect factors of the absorption of the source,air,entrance window,and dead layer of a detector must be considered in the measurement of monoenergetic alpha particles,along with statistical noise and other factors tha... Effect factors of the absorption of the source,air,entrance window,and dead layer of a detector must be considered in the measurement of monoenergetic alpha particles,along with statistical noise and other factors that collectively cause the alpha spectrum to exhibit a well-known low-energy tail.Therefore,the estabUshment of an alpha spectrum detector response function from the perspective of a signaling system must consider the various factors mentioned above.The detector response function is the convolution of an alphaparticle pulse function,two exponential functions,and a Gaussian function,followed by calculation of the parameters of the detector response function using the weighted leastsquares fitting method as proposed in this paper.In our experiment,^(239)Pu alpha spectra were measured by a highresolution,passivated implanted planar silicon(PIPS)detector at 10 levels of vacuum and 10 source-detector distances.The spectrum-fitting results were excellent as evaluated by reduced Chi-square(x^2) and correlation coefficients.Finally,the variation of parameters with vacuum level and source-detector distance was studied.Results demonstrate that σ,τ_1,and τ_2 exhibit no obvious trend of variation with vacuum in the range 2000-20,000 mTorr,and at a confidence level of 95%,the values of τ_1 and τ_2 decline in a similar fashion with source-detector distance by the power exponential function,while the value of a declines linearly. 展开更多
关键词 ALPHA spectrum DETECTOR response function WEIGHTED least SQUARES PIPS DETECTOR
在线阅读 下载PDF
A proposed directional function and wind-wave directional spectrum 被引量:4
3
作者 Wen Shengchang Wu Kejian +1 位作者 Guan Changlong Sun Shicai and Zhang Dacuo (Institute of Physical Oceanography, Ocean University of Oingdao, Oingdao 266003, China) 《Acta Oceanologica Sinica》 SCIE CAS CSCD 1995年第2期155-166,共12页
A directional function for frequencies equal to and larger than the peak frequency of a wind-wave frequency spectrum is constructed by fitting the angular spreading based on the analytically derived directional spectr... A directional function for frequencies equal to and larger than the peak frequency of a wind-wave frequency spectrum is constructed by fitting the angular spreading based on the analytically derived directional spectrum of Wen et al. (1993, Journal of Oceanography, 49(2), 131~147, 149~172). For frequencies smaller than the peak frequency, the directional function is obtained by comparing and analyzing existing formulas. The nondimensional wind-wave frequency spectrum of Wen et al. (1994, Progress in Natural Seience, 4(4). 407~427;4 (5), 586~596) has been used together with the directional function just mentioned to obtain the directional spectrum for easier application. 展开更多
关键词 Wind-wave directional function directional spectrum
在线阅读 下载PDF
The Effects of Xbox Kinect Active Video Gaming on Executive Function, Inhibition, in Children with and without Autism Spectrum Disorder: A Pilot Study 被引量:2
4
作者 Daphne Golden Ling-Yin Liang Nancy Getchell 《Journal of Behavioral and Brain Science》 2022年第6期287-301,共15页
The purpose of this study was to compare the effects of sedentary video gaming (SVG), active video gaming (AVG), and brisk walking (WLK) on inhibition and reaction time using the Flanker task in boys with and without ... The purpose of this study was to compare the effects of sedentary video gaming (SVG), active video gaming (AVG), and brisk walking (WLK) on inhibition and reaction time using the Flanker task in boys with and without autism spectrum disorder (ASD). We had 9 participants with ASD and 10 age-matched participants without ASD perform 20-minute bouts of each activity, and then had them take the Flanker test. Dependent measures were reaction time (RT) and accuracy (ACC). A Chi-Square analysis revealed that the ASD and TD groups significantly differed in the percent of participants who improved in both of these measures. Next, we looked at each of the conditions exclusively within the ASD group and compared congruent and incongruent trials. In the AVG condition, participants improved a significantly higher percentage on ACC. In the SVG condition, participants improved a significantly higher percentage on incongruent in RT;for ACC, a higher percentage improved on the congruent trials. In WLK, participants improved a significantly higher percentage in RT in the congruent condition. 展开更多
关键词 Autism spectrum Disorder Exergaming Physical Activity Cognitive function
在线阅读 下载PDF
A single diffractive optical element implementing spectrum-splitting and beam-concentration functions simultaneously with high diffraction efficiency 被引量:2
5
作者 叶佳声 王进泽 +3 位作者 黄庆礼 董碧珍 张岩 杨国桢 《Chinese Physics B》 SCIE EI CAS CSCD 2013年第3期44-49,共6页
In this paper,a novel method is proposed and employed to design a single diffractive optical element(DOE) for implementing spectrum-splitting and beam-concentration(SSBC) functions simultaneously.We develop an opt... In this paper,a novel method is proposed and employed to design a single diffractive optical element(DOE) for implementing spectrum-splitting and beam-concentration(SSBC) functions simultaneously.We develop an optimization algorithm,through which the SSBC DOE can be optimized within an arbitrary thickness range according to the limitations of modern photolithography technology.Theoretical simulation results reveal that the designed SSBC DOE has a high optical focusing efficiency.It is expected that the designed SSBC DOE should have practical applications in high-efficiency solar cell systems. 展开更多
关键词 diffractive optical element spectrum-splitting and beam-concentration functions thickness optimization algorithm solar cell systems
原文传递
Geant4 simulation of multi-sphere spectrometer response function and the detection of 241Am–Be neutron spectrum 被引量:1
6
作者 Xiao-Fei Jiang Jing Cao +1 位作者 Chun-Yu Jiang Ze-Jie Yin 《Nuclear Science and Techniques》 SCIE CAS CSCD 2017年第12期204-208,共5页
This paper is aimed at detecting the neutron spectrum of^(241)Am–Be, a widely used neutron source, with the SP9 ~3He proportional counter, which is a multi-sphere spectrometer system of eight thermal neutron detector... This paper is aimed at detecting the neutron spectrum of^(241)Am–Be, a widely used neutron source, with the SP9 ~3He proportional counter, which is a multi-sphere spectrometer system of eight thermal neutron detectors embedded in eight polyethylene(PE) spheres of varying diameters. The transport processes of a neutron in the multi-sphere spectrometer are simulated using the Geant4 code. Two sets of response functions of the PE spheres are obtained for calculating the^(241)Am–Be neutron spectrum.Response Function 1 utilizes the thermal neutron scattering model G4 Neutron HPThermal Scattering for neutron energies of ≤4 eV, and Response Function 2 has no thermal treatment. Neutron spectra of an^(241)Am–Be neutron source are measured and compared to those calculated by using the response functions. The results show that response function with thermal treatment is more accurate and closer to the real spectrum. 展开更多
关键词 Response function NEUTRON energy spectrum Multi-sphere GEANT4 241Am–Be G4NeutronHPThermalScattering
在线阅读 下载PDF
Chrestenson Spectrum and Auto-Correlation Function of Inverse Permutations of Quick Trickle Permutations
7
作者 WANG Jue LI Zhengchao ZHAO Yaqun 《Wuhan University Journal of Natural Sciences》 CAS 2008年第5期587-590,共4页
In this paper, a sufficient and necessary condition of quick trickle permutations is given from the point of inverse permutations. The bridge is built between quick trickle permutations and m-value logic functions. By... In this paper, a sufficient and necessary condition of quick trickle permutations is given from the point of inverse permutations. The bridge is built between quick trickle permutations and m-value logic functions. By the methods of the Chrestenson spectrum of m-value logic functions and the auto-correlation function of m-value logic functions to investigate the Chrestenson spectral characteristics and the auto-correlation function charac- teristics of inverse permutations of quick trickle permutations, a determinant arithmetic of quick trickle permutations is given. Using the results, it becomes easy to judge that a permutation is a quick trickle permutation or not by using computer. This gives a new pathway to study constructions and enumerations of quick trickle permutations. 展开更多
关键词 quick trickle permutation chrestenson spectrum auto-correlation function m-value logic function
在线阅读 下载PDF
Simulation of γ spectrum-shifting based on the parameter adjustment of Gaussian function space 被引量:1
8
作者 HUANG Hongquan SHAO qiang +2 位作者 DING Weicheng FANG Fang GONG Dichen 《Nuclear Science and Techniques》 SCIE CAS CSCD 2013年第6期99-104,共6页
Based on the statistical characteristics of energy spectrum and the features of spectrum-shifting in spectrometry,the parameter adjustment method of Gaussian function space was applied in the simulation of spectrum-sh... Based on the statistical characteristics of energy spectrum and the features of spectrum-shifting in spectrometry,the parameter adjustment method of Gaussian function space was applied in the simulation of spectrum-shifting.The transient characteristics of energy spectrum were described by the Gaussian function space,and then the Gaussian function space was transferred by parameter adjustment method.Furthermore,the spectrum-shifting in measurement of energy spectrum was simulated.The applied example shows that the parameters can be adjusted flexibly by this method to meet the various requirements in simulation of energy spectrum-shifting.This method was one parameterized simulation method with good performance for the practical application. 展开更多
关键词 高斯函数 参数调整 空间仿真 基础 Γ谱 仿真应用 函数空间 模拟方法
在线阅读 下载PDF
The Relationship between Executive Functioning and Emotional Intelligence in Children with Autism Spectrum Disorder
9
作者 Jennifer L. Reynolds Alan J. Lincoln +2 位作者 Roya Iravani Varvara Toma Shamayne Brown 《Open Journal of Psychiatry》 2018年第3期253-262,共10页
Children with Autism Spectrum Disorder (ASD) demonstrate marked deficits in the ability to initiate, maintain and sustain meaningful social interaction. While the social-emotional deficits represent a core set of prob... Children with Autism Spectrum Disorder (ASD) demonstrate marked deficits in the ability to initiate, maintain and sustain meaningful social interaction. While the social-emotional deficits represent a core set of problems, persons with ASD also demonstrate significant problems in initiating, sustaining and maintaining appropriate goal directed behaviors. Emotional Intelligence (EI) is a construct that has been successfully applied to a range of skills that allow for the prediction of competent human social behavior. Executive Functions (EF) refer to constructs involving cognitive abilities necessary for initiating, sustaining and maintaining purposeful goal-oriented behavior. While both children and adults with ASD have previously shown to have atypical patterns of EF skills, little is known about EI in either children or adults with ASD. Moreover, there is no study examining the relationship between EI and EF that has been reported in individuals with ASD. The current study examined the relationship between EF and EI in children with ASD. Twenty children with ASD were compared to twenty neurotypical children on self-report and clinical assessments of EI and EF. Although the relationship between EF and EI was not statistically significant, results showed that children with ASD have deficits in interpersonal skills, intrapersonal skills and overall EI when compared to their neurotypical peers. These results suggest that EF and EI are relatively independent domains of development that show compromise in persons with ASD and each may be necessary to support typical socially directed behaviors. 展开更多
关键词 EXECUTIVE functionING EMOTIONAL Intelligence AUTISM spectrum DISORDER
暂未订购
Consistent and Specific Multi-View Functional Brain Networks Fusion for Autism Spectrum Disorder Diagnosis
10
作者 Chaojun Zhang Chengcheng Wang +1 位作者 Limei Zhang Yunling Ma 《Journal of Applied Mathematics and Physics》 2023年第7期1914-1929,共16页
Functional brain networks (FBN) based on resting-state functional magnetic resonance imaging (rs-fMRI) have become an important tool for exploring underlying organization patterns in the brain, which can provide an ob... Functional brain networks (FBN) based on resting-state functional magnetic resonance imaging (rs-fMRI) have become an important tool for exploring underlying organization patterns in the brain, which can provide an objective basis for brain disorders such as autistic spectrum disorder (ASD). Due to its importance, researchers have proposed a number of FBN estimation methods. However, most existing methods only model a type of functional connection relationship between brain regions-of-interest (ROIs), such as partial correlation or full correlation, which is difficult to fully capture the subtle connections among ROIs since these connections are extremely complex. Motivated by the multi-view learning, in this study we propose a novel Consistent and Specific Multi-view FBNs Fusion (CSMF) approach. Concretely, we first construct multi-view FBNs (i.e., multiple types of FBNs modelling various relationships among ROIs), and then these FBNs are decomposed into a consistent representation matrix and their own specific matrices which capture their common and unique information, respectively. Lastly, to obtain a better brain representation, it is fusing the consistent and specific representation matrices in the latent representation spaces of FBNs, but not directly fusing the original FBNs. This potentially makes it more easily to find the comprehensively brain connections. The experimental results of ASD identification on the ABIDE datasets validate the effectiveness of our proposed method compared to several state-of-the-art methods. Our proposed CSMF method achieved 72.8% and 76.67% classification performance on the ABIDE dataset. 展开更多
关键词 functional Brain Network FUSION CONSISTENCY SPECIFICITY Autism spectrum Disorder
在线阅读 下载PDF
雷达通信一体化波形设计综述
11
作者 唐波 吴文俊 +1 位作者 夏学成 王雄鹏 《国防科技大学学报》 北大核心 2026年第2期349-366,共18页
雷达通信一体化通过硬件资源共享与信号波形协同设计,突破传统分立架构下的频谱冲突、硬件冗余和电磁兼容性瓶颈,提升平台的综合作战效能与战场生存能力。系统回顾了雷达通信一体化技术从概念萌芽、架构演进到系统实现的发展历程,重点... 雷达通信一体化通过硬件资源共享与信号波形协同设计,突破传统分立架构下的频谱冲突、硬件冗余和电磁兼容性瓶颈,提升平台的综合作战效能与战场生存能力。系统回顾了雷达通信一体化技术从概念萌芽、架构演进到系统实现的发展历程,重点分析了基于线性调频、正交频分复用、正交时频空等主流信号体制的雷达通信一体化波形设计方法;深入探讨了以感知性能为中心的多种波形设计准则,包括方向图匹配、克拉美罗界优化及信息论方法等;梳理了从软件无线电兼容验证、机载多模态波形融合,到多节点与多域协同的工程实践之路,清晰展现了雷达通信一体化技术从理论到实践的演进路径。通过全面展示雷达通信一体化系统从常规体制到多输入多输出体制,再到原理样机验证的完整技术脉络,为未来雷达通信一体化技术的研究与开发提供系统的理论指导和实践参考。 展开更多
关键词 频谱共享 雷达通信一体化 波形设计 原型验证
在线阅读 下载PDF
基于频谱泄漏抑制的改进FFT宽频测量算法
12
作者 徐恒山 赵杰 +3 位作者 李旭涛 钟怡宸 任勇 马辉 《电力系统及其自动化学报》 北大核心 2026年第3期56-64,共9页
针对传统快速傅里叶变换方法测量宽频信号时频谱泄漏导致精度下降的问题,提出一种改进快速傅里叶变换宽频信号测量算法。首先,基于傅里叶变换分析宽频信号的频谱分布,发现采样频率与信号频率不匹配及信号截断效应会导致频谱泄漏;然后,采... 针对传统快速傅里叶变换方法测量宽频信号时频谱泄漏导致精度下降的问题,提出一种改进快速傅里叶变换宽频信号测量算法。首先,基于傅里叶变换分析宽频信号的频谱分布,发现采样频率与信号频率不匹配及信号截断效应会导致频谱泄漏;然后,采用Nuttall-Kaiser组合窗和周期补偿函数对频谱泄漏问题进行校正,利用全相位快速傅里叶变换算法的卷积窗性质对旁瓣衰减进行抑制,以降低频谱泄漏对频谱精度和幅度的影响;最后,采用西北某电站实际信号对所提方法进行验证。结果表明,相较于传统快速傅里叶变换方法,所提的改进快速傅里叶变换方法不仅能精确获取宽频信号的幅值和频率等信息,还能显著减少信号频率泄漏,提升信号测量精度。 展开更多
关键词 宽频测量算法 快速傅里叶变换 频谱泄漏 窗函数
在线阅读 下载PDF
基于不相交码的严格几乎最优弹性函数构造
13
作者 季彦晗 孙玉娟 李路阳 《密码学报(中英文)》 北大核心 2026年第1期109-121,共13页
布尔函数是流密码系统中的核心非线性部件.为了流密码系统免受各种攻击,如最佳仿射逼近攻击、相关攻击和代数攻击等,需要布尔函数满足多种密码学指标,如高的非线性度、适当的弹性阶和好的代数性质.然而,布尔函数的弹性和非线性具有制约... 布尔函数是流密码系统中的核心非线性部件.为了流密码系统免受各种攻击,如最佳仿射逼近攻击、相关攻击和代数攻击等,需要布尔函数满足多种密码学指标,如高的非线性度、适当的弹性阶和好的代数性质.然而,布尔函数的弹性和非线性具有制约关系,如何构造高非线性度弹性布尔函数是密码函数设计领域的重要问题.本文借鉴传统Maiorana-McFarland(M-M)类构造思想,利用一类特殊的不相交码构造出一类Walsh谱交错分布的布尔函数族.对这族函数加以级联,并进行一些必要的修改,由此实现了一种高非线性度弹性函数的构造方法.此方法可将k变元(k≥6)具有严格几乎最优非线性度的平衡函数扩展到3k变元函数的情形,并可在不损失非线性度的前提下将所得到的平衡函数修改为弹性函数. 展开更多
关键词 布尔函数 不相交谱函数 不相交码 非线性度 弹性
在线阅读 下载PDF
基于独立成分分析法的光纤通信网络频谱分配研究
14
作者 杨华 胡珺 邱祥阳 《激光杂志》 北大核心 2026年第1期200-207,共8页
为了提高光纤通信网络频谱分配质量,提出了基于独立成分分析法的光纤通信网络频谱分配方法。通过自适应步长独立成分分析法对光纤通信网络信道均衡处理,即以两个光纤通信网络源信号间的统计独立性作为判断标准来构建信道频响分离矩阵,... 为了提高光纤通信网络频谱分配质量,提出了基于独立成分分析法的光纤通信网络频谱分配方法。通过自适应步长独立成分分析法对光纤通信网络信道均衡处理,即以两个光纤通信网络源信号间的统计独立性作为判断标准来构建信道频响分离矩阵,信道频响分离矩阵对于原始信号中的干扰成分进行补偿,以信道均衡处理后的光纤通信网络为基础,确定最大化频谱利用率、最小化干扰、最大化公平性等目标函数,以此搭建光纤通信网络频谱分配模型,利用蛙跳算法对于该模型进行求解,所得最优解即为最优的光纤通信网络频谱分配方案。实验结果表明,所提方法的丢包率最大值为4.12%,频谱利用率为24.12%,带宽阻塞率为18.87%,光纤通信网络频谱分配效果好。 展开更多
关键词 独立成分分析法 光纤通信网络 频谱分配 目标函数 分配模型 蛙跳算法
原文传递
随机地震动过程的小波降维表达
15
作者 刘章军 周江林 +1 位作者 张伟 刘子心 《振动工程学报》 北大核心 2026年第2期403-412,共10页
基于确定性函数的小波变换,结合非平稳随机过程的谱分解理论,推导出其小波系数也是一个非平稳随机过程。在此基础上建立了小波系数的源谱表达,通过引入随机正交函数的降维方法,得到基于小波变换的非平稳随机过程降维表达。选取MH、MO及... 基于确定性函数的小波变换,结合非平稳随机过程的谱分解理论,推导出其小波系数也是一个非平稳随机过程。在此基础上建立了小波系数的源谱表达,通过引入随机正交函数的降维方法,得到基于小波变换的非平稳随机过程降维表达。选取MH、MO及MLP三种小波,针对它们的离散方式和尺度范围,通过比较分析确定了最优方案。实现了采用两个基本随机变量即可生成地震动加速度过程的代表性样本集合。算例表明,本文方法在精度和非平稳性方面优于传统谱表示方法,并通过与实测强震记录拟合验证了该方法的工程适用性。值得说明的是,降维方法是一种全概率方法,即生成的数百条代表性样本可构成一个完备的概率集,为结合概率密度演化理论进行复杂工程结构的精细化抗震分析奠定了基础。 展开更多
关键词 非平稳过程 小波变换 演变功率谱 随机正交函数 降维表达
在线阅读 下载PDF
功能性近红外光谱技术在孤独症谱系障碍早期筛查领域应用的研究进展
16
作者 何宇杉 王丙森 高东平 《医学信息学杂志》 2026年第3期71-77,共7页
目的/意义总结功能性近红外光谱技术(functional near-infrared spectroscopy,fNIRS)应用于孤独症谱系障碍(autism spectrum disorder,ASD)早期筛查领域的研究进展,以期为ASD的早期筛查与精准干预提供科学依据。方法/过程检索PubMed、We... 目的/意义总结功能性近红外光谱技术(functional near-infrared spectroscopy,fNIRS)应用于孤独症谱系障碍(autism spectrum disorder,ASD)早期筛查领域的研究进展,以期为ASD的早期筛查与精准干预提供科学依据。方法/过程检索PubMed、Web of Science、Embase数据库,提取纳入文献中的样本特征、刺激方式、fNIRS参数及主要结果,并进行系统分析。结果/结论 fNIRS能够有效测量大脑功能指标,进而发现高低风险婴儿间皮层与皮质激活、功能性连接、言语感知神经相关性等方面的差异,为ASD早期筛查提供客观依据,未来应开展多中心、标准化研究,推动fNIRS从研究工具向临床常规筛查手段转化。 展开更多
关键词 孤独症谱系障碍 功能性近红外光谱技术 家族风险 氧合血红蛋白
暂未订购
针刺技术在孤独症谱系障碍治疗中的原理与应用
17
作者 郗梓彤 张嵘 《中国儿童保健杂志》 北大核心 2026年第3期246-249,共4页
本研究系统梳理了针刺技术治疗孤独症谱系障碍(ASD)的研究进展,涵盖历史渊源、技术变革、假设提出、机制探索、临床验证及成果转化路径。研究回溯至隋代医著中对“惛塞、语迟”等类似重度ASD症状的记载。在现代脑科学框架下,本研究聚焦... 本研究系统梳理了针刺技术治疗孤独症谱系障碍(ASD)的研究进展,涵盖历史渊源、技术变革、假设提出、机制探索、临床验证及成果转化路径。研究回溯至隋代医著中对“惛塞、语迟”等类似重度ASD症状的记载。在现代脑科学框架下,本研究聚焦针刺通过激活外周-中枢神经通路,促进社交神经递质的释放,以改善ASD患者的脑发育。基于前期基础研究发现,团队将传统手针发展为经皮穴位电刺激(TEAS)技术,并采用特定参数刺激对合谷、内关、足三里与三阴交为主的穴位进行标准化治疗方案。多中心临床研究结果显示:在统一行为干预基础上联合TEAS治疗,可显著提高临床疗效,其中“冷漠型/被动型”社交表型患儿获益最为显著。外周血浆催产素(OXT)与精氨酸后叶加压素(AVP)水平的变化,以及多模态脑影像[结构像、静息态功能性磁共振成像(fMRI)、弥散张量成像(DTI)]的一致性变化支持了TEAS通过催产素通路促进感知觉恢复,增强社交动机、降低焦虑情绪的作用假说。临床评估与家长随访数据表明,该疗效具有可重复性。最后,本研究进一步探讨了从分型评估到精准化参数设定、多模态评估体系与家庭可操作化路径的整合意义,提出未来需以更大规模、多中心、分层随机对照试验和多组学整合来验证疗效普适性并进一步阐明分子与网络机制。 展开更多
关键词 经皮穴位电刺激 孤独症谱系障碍 社交分型 功能性磁共振成像 弥散张量成像
原文传递
石质山地主要树种根序功能性状分异的生态适应策略
18
作者 韦柳端 于淼 +5 位作者 林建 杨智慧 董天心 户佐佑 姜文珊 徐程扬 《生态学报》 北大核心 2026年第4期2024-2035,共12页
测量两组根序(1—3级根和4—5级根)的7个功能性状,分析其在不同石砾含量梯度下的变化,以探讨观赏树种在石质山地环境中,细根性状的变异及其适应策略。结果表明:(1)随着石砾含量的增加,1—3级根的比根表面积(SRA)和比根长(SRL)随石砾含... 测量两组根序(1—3级根和4—5级根)的7个功能性状,分析其在不同石砾含量梯度下的变化,以探讨观赏树种在石质山地环境中,细根性状的变异及其适应策略。结果表明:(1)随着石砾含量的增加,1—3级根的比根表面积(SRA)和比根长(SRL)随石砾含量增加显著减少,而根直径(RD)、根组织密度(RTD)和根碳含量(RCC)显著增加。4—5级根序则相反,即随石砾含量增加4—5级根的资源吸收能力增强;(2)不同根序在石砾含量梯度上表现为两个维度:PC1(占总变异的49.04%)由“协作”梯度(与RD和SRA相关)解释;PC2(占总变异的18.08%)代表了一个资源获取梯度,与RTD和根氮含量(RNC)相关,即获取-保守策略。1—3级根序主要与PC2有关,而4—5级根序在PC1上得分更高。(3)根系性状网络结构也随着石砾环境梯度也相应发生变化,土壤石砾越多性状之间的相关性和连接性越强,同时1—3级根序性状的网络结构比4—5级根序复杂;总体而言,不同根序承担的功能不同,1—3级根倾向于“自己做”的资源获取策略,而4—5级根则更倾向于与菌根真菌合作的资源保守策略。在石质环境中根序发生功能转变,观赏树种利用低级根粗化而高级根细化的特殊根系性状可能更具有优势。这些发现有助于更好地理解植物在石质土壤中的生存策略和机制,并为树木在石质山地区域的持续生存提供了理论依据。 展开更多
关键词 石质山地 根序 根系功能性状 根系经济谱 适应策略
在线阅读 下载PDF
矿区6种藤本植物的叶功能性状及其对覆土厚度的响应
19
作者 刘仁 袁小东 +6 位作者 孙韵 蔡宗明 何平 宋云霞 喻龙华 张华聪 厉月桥 《西南大学学报(自然科学版)》 北大核心 2026年第1期99-114,共16页
明确6种藤本植物在不同覆土厚度下的适应性差异,筛选出耐薄土或厚土的优势物种,为矿区人工植被重建提供科学选种和覆土厚度依据,提升生态修复效率。以矿区中6种藤本植物(五叶地锦、葛藤、常春藤、凌霄、常春油麻藤、爬山虎)为试验材料,... 明确6种藤本植物在不同覆土厚度下的适应性差异,筛选出耐薄土或厚土的优势物种,为矿区人工植被重建提供科学选种和覆土厚度依据,提升生态修复效率。以矿区中6种藤本植物(五叶地锦、葛藤、常春藤、凌霄、常春油麻藤、爬山虎)为试验材料,利用主成分分析法、隶属函数法研究3种覆土厚度下6种藤本植物叶功能性状及氮磷养分策略的差异,对6种藤本植物各项指标进行综合分析及评价。结果表明:①在覆土厚度20 cm下五叶地锦生长状况最佳;在覆土厚度40 cm下爬山虎和凌霄生长优势较高;在覆土厚度60 cm下葛藤、常春藤和常春油麻藤表现出较好的适应性和生长优势。②五叶地锦和凌霄在覆土厚度20 cm下增加根系投资以增强养分获取,在覆土厚度60 cm下则转向增加叶生物量以优化光合作用;葛藤和常春油麻藤在各厚度下均表现出较高的生物量积累,显示出较强的适应潜力;在覆土厚度20 cm下葛藤和常春油麻藤表现为“快投资-回报”资源获取型策略,具有高比叶面积、低叶干物质含量特征,利于快速生长与资源捕获,而爬山虎和常春藤则倾向于“慢投资-回报”资源保守型策略,具有高比叶质量和叶干物质含量,增强了其对贫瘠环境的耐受性。③所有藤本植物生长均受氮磷限制,不同藤本植物在不同覆土厚度下对氮磷养分的吸收与分配策略存在差异。五叶地锦在薄土层(20 cm)下茎根氮磷吸收量突出;葛藤与常春油麻藤则在厚土层(60 cm)下各器官养分吸收量较高,体现了豆科植物的固氮优势。总的来看,藤本植物通过调整生物量分配、叶片形态和养分吸收策略来适应不同覆土厚度以提升生长和竞争力。 展开更多
关键词 藤本植物 叶功能性状 叶经济谱 覆土厚度
原文传递
儿童孤独症谱系障碍睡眠情况与执行功能神经发育的关系
20
作者 陈晓玉 周咏梅 刘琴 《公共卫生与预防医学》 2026年第1期167-170,共4页
目的探究儿童孤独症谱系障碍(autism spectrum disorder,ASD)睡眠情况调查及与执行功能、神经发育的关系。方法回顾性收集2023年4月至2025年1月期间在成都市第三人民医院收治的ASD患儿346例的病历资料,通过儿童睡眠习惯问卷(Children′s... 目的探究儿童孤独症谱系障碍(autism spectrum disorder,ASD)睡眠情况调查及与执行功能、神经发育的关系。方法回顾性收集2023年4月至2025年1月期间在成都市第三人民医院收治的ASD患儿346例的病历资料,通过儿童睡眠习惯问卷(Children′s Sleep Habits Questionnaire,CSHQ)调查患儿的睡眠情况,根据分值将患儿分为睡眠良好组(CSHQ评分<41分)189例,与睡眠障碍组(CSHQ评分≥41分)157例。比较两组患儿的一般资料,分别采用中文版学龄前儿童执行功能行为评定问卷(Behavior Rating Inventory of Executive Function-Preschool Version,BRIEF-P)和0~6岁儿童发育行为评估量表(儿心量表-Ⅱ),分析ASD患儿睡眠情况与执行功能、神经发育的关系。结果346例患儿CSHQ评分(39.08±3.24)分,其中CSHQ评分≥41分共157例,<41分共189例。睡眠障碍组存在既往严重病史的比例、执行功能评分明显高于睡眠良好组,发育商数的评估结果则低于睡眠良好组(P<0.05)。logistic回归分析结果显示,执行能力和神经发育均与ASD患儿睡眠状况密切相关(P<0.05)。经Spearman相关性分析显示,ASD患儿睡眠情况与执行功能评分呈负相关(r=-0.456,P<0.05);与发育商数的DQ呈正相关(r=0.547,P<0.05)。结论ASD患儿睡眠障碍发生率较高,睡眠情况与执行功能、神经发育密切相关,临床应重视ASD患儿的睡眠问题,采取有效的干预措施,以改善患儿的睡眠质量,并促进其执行功能和神经发育的训练。 展开更多
关键词 儿童孤独症谱系障碍 睡眠 执行功能 神经发育
原文传递
上一页 1 2 124 下一页 到第
使用帮助 返回顶部