期刊文献+
共找到6,198篇文章
< 1 2 250 >
每页显示 20 50 100
Euler’s First-Order Explicit Method–Peridynamic Differential Operator for Solving Population Balance Equations of the Crystallization Process
1
作者 Chunlei Ruan Cengceng Dong +2 位作者 Kunfeng Liang Zhijun Liu Xinru Bao 《Computer Modeling in Engineering & Sciences》 SCIE EI 2024年第3期3033-3049,共17页
Using Euler’s first-order explicit(EE)method and the peridynamic differential operator(PDDO)to discretize the time and internal crystal-size derivatives,respectively,the Euler’s first-order explicit method–peridyna... Using Euler’s first-order explicit(EE)method and the peridynamic differential operator(PDDO)to discretize the time and internal crystal-size derivatives,respectively,the Euler’s first-order explicit method–peridynamic differential operator(EE–PDDO)was obtained for solving the one-dimensional population balance equation in crystallization.Four different conditions during crystallization were studied:size-independent growth,sizedependent growth in a batch process,nucleation and size-independent growth,and nucleation and size-dependent growth in a continuous process.The high accuracy of the EE–PDDO method was confirmed by comparing it with the numerical results obtained using the second-order upwind and HR-van methods.The method is characterized by non-oscillation and high accuracy,especially in the discontinuous and sharp crystal size distribution.The stability of the EE–PDDO method,choice of weight function in the PDDO method,and optimal time step are also discussed. 展开更多
关键词 Population balance equation CRYsTALLIZATION peridynamic differential operator Euler’s first-order explicit method
下载PDF
Energy Stable Nodal DG Methods for Maxwell’s Equations of Mixed-Order Form in Nonlinear Optical Media
2
作者 Maohui Lyu Vrushali A.Bokil +1 位作者 Yingda Cheng Fengyan Li 《Communications on Applied Mathematics and Computation》 EI 2024年第1期30-63,共34页
In this work,we develop energy stable numerical methods to simulate electromagnetic waves propagating in optical media where the media responses include the linear Lorentz dispersion,the instantaneous nonlinear cubic ... In this work,we develop energy stable numerical methods to simulate electromagnetic waves propagating in optical media where the media responses include the linear Lorentz dispersion,the instantaneous nonlinear cubic Kerr response,and the nonlinear delayed Raman molecular vibrational response.Unlike the first-order PDE-ODE governing equations considered previously in Bokil et al.(J Comput Phys 350:420–452,2017)and Lyu et al.(J Sci Comput 89:1–42,2021),a model of mixed-order form is adopted here that consists of the first-order PDE part for Maxwell’s equations coupled with the second-order ODE part(i.e.,the auxiliary differential equations)modeling the linear and nonlinear dispersion in the material.The main contribution is a new numerical strategy to treat the Kerr and Raman nonlinearities to achieve provable energy stability property within a second-order temporal discretization.A nodal discontinuous Galerkin(DG)method is further applied in space for efficiently handling nonlinear terms at the algebraic level,while preserving the energy stability and achieving high-order accuracy.Indeed with d_(E)as the number of the components of the electric field,only a d_(E)×d_(E)nonlinear algebraic system needs to be solved at each interpolation node,and more importantly,all these small nonlinear systems are completely decoupled over one time step,rendering very high parallel efficiency.We evaluate the proposed schemes by comparing them with the methods in Bokil et al.(2017)and Lyu et al.(2021)(implemented in nodal form)regarding the accuracy,computational efficiency,and energy stability,by a parallel scalability study,and also through the simulations of the soliton-like wave propagation in one dimension,as well as the spatial-soliton propagation and two-beam interactions modeled by the two-dimensional transverse electric(TE)mode of the equations. 展开更多
关键词 Maxwell’s equations Kerr and Raman Discontinuous Galerkin method Energy stability
下载PDF
Research on the Application of Montessori Education Method in Cognitive Training of Patients with Alzheimer’s Disease
3
作者 Wei Wang Faridah Mohd Said 《Journal of Clinical and Nursing Research》 2024年第5期336-341,共6页
Objective:To study the application of the Montessori education method in cognitive training in patients with Alzheimer’s disease(AD).Methods:40 cases of senile dementia patients who were admitted to our hospital from... Objective:To study the application of the Montessori education method in cognitive training in patients with Alzheimer’s disease(AD).Methods:40 cases of senile dementia patients who were admitted to our hospital from January 2022 to January 2023 were selected and randomly divided into an intervention group and a control group according to the single and double number table method,with 20 cases in each group.The intervention group used the Montessori education method,the principle of which was to implement individualized health interventions based on the individual conditions of the patients,for a period of 6 months;the control group was given conventional treatment and nursing of the disease.The Mini-Mental State Examination(MMSE)was used to compare the effects of the two groups of patients before and after health intervention and conduct statistical analysis.Results:The score of the intervention group was higher than that of the control group,and there was a statistical difference between the two(P<0.05).Conclusion:Implementing the Montessori education method for diagnosed Alzheimer’s patients can effectively improve their cognitive function and delay the progress of further dementia. 展开更多
关键词 Montessori education method Alzheimer’s disease Cognitive training
下载PDF
基于Seed-PCG法的列车-轨道-地基土三维随机振动GPU并行计算方法
4
作者 朱志辉 冯杨 +2 位作者 杨啸 李昊 邹有 《Journal of Central South University》 SCIE EI CAS CSCD 2024年第1期302-316,共15页
为了解决列车-轨道-地基土三维有限元模型随机多样本计算效率低的问题,本文提出了一种基于Seed-PCG法的高效并行计算方法。基于有限元法和虚拟激励法建立轨道不平顺激励下的三维列车-轨道-地基土耦合随机振动分析模型;针对车致地基土随... 为了解决列车-轨道-地基土三维有限元模型随机多样本计算效率低的问题,本文提出了一种基于Seed-PCG法的高效并行计算方法。基于有限元法和虚拟激励法建立轨道不平顺激励下的三维列车-轨道-地基土耦合随机振动分析模型;针对车致地基土随机振动分析产生的多右端项线性方程组求解问题,采用Seed-PCG方法进行求解。通过PCG方法求解种子系统得到的Krylov子空间进行投影,以改进其余线性方程组的初始解和对应的初始残量,有效提高了PCG法的收敛速度,最后,在MATLABCUDA混合平台上开发了并行计算程序。数值算例表明:相同计算平台下的该方法相比多点同步算法获得了104.2倍的加速;相比PCG法逐个求解方案减少了18%的迭代次数,获得了1.21倍的加速。 展开更多
关键词 seed-PCG法 多右端项线性方程组 随机振动 GPU并行计算 列车-轨道-地基土耦合模型
下载PDF
晶种法直接水热合成含磷ZSM-5分子筛及其芳构化性能研究
5
作者 曹健 郝坤 +5 位作者 邢梦姣 王飞 陶智超 杨勇 相宏伟 李永旺 《低碳化学与化工》 CAS 北大核心 2024年第6期87-94,共8页
费托合成油品向高辛烷值汽油转化的流化床体系中,水蒸气的存在极易导致ZSM-5分子筛发生不可逆的水热失活,而磷的引入能提高ZSM-5分子筛的水热稳定性。采用晶种法在无胺体系下直接水热合成了含磷ZSM-5分子筛(HS-P-Z5),并与常规浸渍法得... 费托合成油品向高辛烷值汽油转化的流化床体系中,水蒸气的存在极易导致ZSM-5分子筛发生不可逆的水热失活,而磷的引入能提高ZSM-5分子筛的水热稳定性。采用晶种法在无胺体系下直接水热合成了含磷ZSM-5分子筛(HS-P-Z5),并与常规浸渍法得到的含磷ZSM-5分子筛(IM-P-Z5)进行了对比。通过XRD、SEM和N2吸/脱附等对水热处理前后的ZSM-5分子筛进行了表征,通过水洗实验考察了磷元素的流失情况,并以1-辛烯为探针分子评价了ZSM-5分子筛的芳构化性能。结果表明,HS-P-Z5比IM-P-Z5具有更高强度的特征衍射峰、更多的微孔结构和酸量。水洗实验和NMR表征结果表明,HS-P-Z5具有更加稳定的磷铝结构,磷物种不易被洗掉,故其具有更好的水热稳定性,在水热处理后能够保留更多分子筛的微孔结构以及强酸位点。HS-P-Z5-ST(ST表示水热处理)具有最高的芳烃选择性,在反应时间730 min时,其芳烃选择性为23.1%,高于IMP-Z5-ST(18.4%)以及Z5-ST(11.2%)。 展开更多
关键词 含磷ZsM-5分子筛 晶种法 芳构化 水热稳定性
下载PDF
ADASYN与类别逆比例加权法在阿尔茨海默病不平衡数据中的应用
6
作者 杨慧 易付良 +7 位作者 陈杜荣 秦瑶 韩红娟 崔靖 白文琳 马艺菲 张荣 余红梅 《中国卫生统计》 CSCD 北大核心 2024年第2期175-180,共6页
目的利用自适应合成抽样(adaptive synthetic sampling,ADASYN)与类别逆比例加权法处理类别不平衡数据,结合分类器构建模型对阿尔茨海默病(alzheimer′s disease,AD)患者疾病进程进行分类预测。方法数据源自阿尔茨海默病神经影像学计划(... 目的利用自适应合成抽样(adaptive synthetic sampling,ADASYN)与类别逆比例加权法处理类别不平衡数据,结合分类器构建模型对阿尔茨海默病(alzheimer′s disease,AD)患者疾病进程进行分类预测。方法数据源自阿尔茨海默病神经影像学计划(Alzheimer′s disease neuroimaging initiative,ADNI),经随机森林填补缺失值,弹性网络筛选特征子集后,利用ADASYN与类别逆比例加权法处理类别不平衡数据。分别结合随机森林(random forest,RF)、支持向量机(support vector machine,SVM)构建四种模型:ADASYN-RF、ADASYN-SVM、加权随机森林(weighted random forest,WRF)、加权支持向量机(weighted support vector machine,WSVM),与RF、SVM比较分类性能。模型评价指标为宏观平均精确率(macro-average of precision,macro-P)、宏观平均召回率(macro-average of recall,macro-R)、宏观平均F1值(macro-average of F1-score,macro-F1)、准确率(accuracy,ACC)、Kappa值和AUC(area under the ROC curve)。结果ADASYN-RF的分类性能最优(Kappa值为0.938,AUC为0.980),ADASYN-SVM次之。利用ADASYN-RF预测得到的重要分类特征分别为CDRSB、LDELTOTAL、MMSE,在临床上均可得到证实。结论ADASYN与类别逆比例加权法都能辅助提升分类器性能,但ADASYN算法更优。 展开更多
关键词 类别不平衡 ADAsYN 加权法 阿尔茨海默病 分类
下载PDF
电液3-UPS/S并联稳定平台参数振动特性分析
7
作者 袁晓明 王维锜 +1 位作者 庞浩东 张立杰 《振动与冲击》 EI CSCD 北大核心 2024年第5期52-61,共10页
针对电液3-UPS/S并联稳定平台驱动液压缸的压力脉动所产生的参数振动,建立了稳定平台的参数振动方程并利用多尺度法求解了主共振响应与组合共振响应的一次近似解;分析了主共振与组合共振响应特性以及振动幅值在初始工作空间内的变化规律... 针对电液3-UPS/S并联稳定平台驱动液压缸的压力脉动所产生的参数振动,建立了稳定平台的参数振动方程并利用多尺度法求解了主共振响应与组合共振响应的一次近似解;分析了主共振与组合共振响应特性以及振动幅值在初始工作空间内的变化规律,最后采用四阶龙格库塔法与模态试验对参数振动模型进行验证。结果表明:数值解与理论解之间的最大误差为4.20%,固有频率理论值与试验值之间的最大误差为4.66%,可验证参数振动模型的正确性。 展开更多
关键词 电液3-UPs/s并联稳定平台 压力脉动 参数振动 多尺度法 振动特性
下载PDF
2024年1月23日乌什M_(S)7.1地震序列频谱偏移特征分析
8
作者 刘萍 宋春燕 牛中华 《内陆地震》 2024年第2期135-142,共8页
采用P波初动方法计算了乌什M_(S)7.1地震序列中M_(S)≥4.0地震的震源机制解,震源机制解在时间上存在前期一致性较好,后期一致性紊乱的特点。空间上,乌什县内震源机制解类型多为逆冲型,阿合奇县内震源机制解类型多为走滑型。利用新疆地... 采用P波初动方法计算了乌什M_(S)7.1地震序列中M_(S)≥4.0地震的震源机制解,震源机制解在时间上存在前期一致性较好,后期一致性紊乱的特点。空间上,乌什县内震源机制解类型多为逆冲型,阿合奇县内震源机制解类型多为走滑型。利用新疆地震台网数字波形资料和快速傅里叶变换方法,计算乌什M_(S)7.1地震序列中M_(S)≥5.0地震序列的频率谱,计算结果显示,乌什县内发生的5级余震前期有频谱偏移特征,最后一个5级地震频带变宽,频谱偏移特征消失;阿合奇县内发生的5级余震均出现了频谱偏移特征。 展开更多
关键词 乌什M_(s)7.1地震 震源机制解 频谱偏移法
下载PDF
基于D-S证据理论改进AHP-熵权的流域洪涝灾害评估研究
9
作者 苑希民 高瑞梅 +1 位作者 田福昌 侯玮 《水资源与水工程学报》 CSCD 北大核心 2024年第1期9-16,共8页
考虑致灾因子危险性、孕灾环境敏感性以及承灾体易损性,选取指标构建小清河流域洪涝灾害风险评估指标体系,提出一种基于D-S证据理论的改进AHP-熵权法计算指标权重,求取洪涝灾害风险指数,运用自然断点分级法确定洪涝灾害风险等级,分析小... 考虑致灾因子危险性、孕灾环境敏感性以及承灾体易损性,选取指标构建小清河流域洪涝灾害风险评估指标体系,提出一种基于D-S证据理论的改进AHP-熵权法计算指标权重,求取洪涝灾害风险指数,运用自然断点分级法确定洪涝灾害风险等级,分析小清河流域洪涝灾害风险空间分布情况。结果表明:小清河流域洪涝灾害风险总体上表现出南低北高的趋势,其中高风险区和较高风险区分别占流域面积的8.7%和14.3%,主要分布在小清河干流以及主要支流两岸。所得评估结果同“利奇马”台风发生期间实际洪灾风险分布情况一致,对比证明基于D-S证据理论的改进AHP-熵权法优于AHP和熵权法,可为小清河流域防洪减灾决策提供依据。 展开更多
关键词 D-s证据理论 AHP 熵权法 洪涝灾害评估 小清河流域
下载PDF
Continuum Skyrme Hartree-Fock-Bogoliubov theory with Green’s function method for neutron-rich Ca,Ni,Zr,and Sn isotopes 被引量:1
10
作者 En-Bo Huo Ke-Ran Li +2 位作者 Xiao-Ying Qu Ying Zhang Ting-Ting Sun 《Nuclear Science and Techniques》 SCIE EI CAS CSCD 2023年第7期162-178,共17页
The possible exotic nuclear properties in the neutron-rich Ca,Ni,Zr,and Sn isotopes are examined with the continuum Skyrme Hartree-Fock-Bogoliubov theory in the framework of the Green’s function method.The pairing co... The possible exotic nuclear properties in the neutron-rich Ca,Ni,Zr,and Sn isotopes are examined with the continuum Skyrme Hartree-Fock-Bogoliubov theory in the framework of the Green’s function method.The pairing correlation,the couplings with the continuum,and the blocking effects for the unpaired nucleon in odd-A nuclei are properly treated.The Skyrme interaction SLy4 is adopted for the ph channel and the density-dependentinteraction is adopted for the pp chan-nel,which well reproduce the experimental two-neutron separation energies S_(2n)and one-neutron separation energies Sn.It is found that the criterion S_(n)>0 predicts a neutron drip line with neutron numbers much smaller than those for S_(2n)>0.Owing to the unpaired odd neutron,the neutron pairing energies−E_(pair)in odd-A nuclei are much lower than those in the neighbor-ing even-even nuclei.By investigating the single-particle structures,the possible halo structures in the neutron-rich Ca,Ni,and Sn isotopes are predicted,where sharp increases in the root-mean-square(rms)radii with significant deviations from the traditional rA^(1∕3)rule and diffuse spatial density distributions are observed.Analyzing the contributions of various partial waves to the total neutron densityρlj(r)∕ρ(r)reveals that the orbitals located around the Fermi surface-particularly those with small angular momenta-significantly affect the extended nuclear density and large rms radii.The number of neutrons Nλ(N_(0))occupying above the Fermi surfacen(continuum threshold)is discussed,whose evolution as a function of the mass number A in each isotope is consistent with that of the pairing energy,supporting the key role of the pairing correlation in halo phenomena. 展开更多
关键词 Neutron-rich nuclei Neutron halo skyrme Hartree-Fock-Bogoliubov theory Green’s function method
下载PDF
A Method for Detection of Main Metabolites in Aromatic Rice Seeds 被引量:7
11
作者 Bo PENG Dongyan KONG +12 位作者 Xiaohua SONG Huilong LI Lulu HE Andong GONG Yanfang SUN Ruihua PANG Lin LIU Jintao LI Qiying ZHOU Yaqin HUANG Bin DUAN Shizhi SONG Hongyu YUAN 《Agricultural Biotechnology》 CAS 2018年第1期112-116,共5页
[ Objective] A method was developed for the analysis of main metabolites in aromatic rice seeds by gas chromatography-mass spectrometry (GC-MS). [ Method] The main metabolites in seeds of 9 different aromatic rice v... [ Objective] A method was developed for the analysis of main metabolites in aromatic rice seeds by gas chromatography-mass spectrometry (GC-MS). [ Method] The main metabolites in seeds of 9 different aromatic rice varieties were compared and analyzed with two methods. Method 1 : the compound was extracted by the mixture of anhydrous ethanol and methylene chloride ( WV = 1:1 ) at 60 ℃ for 3 h in water bath; the extract was isolated and detected by gas chromatography-mass spectrometry using HP-5 capillary column with scan monitoring mode. Method 2: the main metabolites in aromatic rice seeds were detected using headspaee solid phase micro-extraction and gas chromatography mass spectrometry (GC-MS). [ Result ] Fifteen types of common metabolites were found in 9 different aromatic rice varieties. Method 1 was more effective than method 2 in detecting the main metabolites in aromatic rice seeds. [ Conclusion] This study provides an important reference for clarifying the metabolic pathway of main metabolites in aromatic rice and lays the foundation for further rice breeding. 展开更多
关键词 Aromatic flee seed method METABOLITEs GC-Ms
下载PDF
On the Approximation of Fractal-Fractional Differential Equations Using Numerical Inverse Laplace Transform Methods
12
作者 Kamran Siraj Ahmad +2 位作者 Kamal Shah Thabet Abdeljawad Bahaaeldin Abdalla 《Computer Modeling in Engineering & Sciences》 SCIE EI 2023年第6期2743-2765,共23页
Laplace transform is one of the powerful tools for solving differential equations in engineering and other science subjects.Using the Laplace transform for solving differential equations,however,sometimes leads to sol... Laplace transform is one of the powerful tools for solving differential equations in engineering and other science subjects.Using the Laplace transform for solving differential equations,however,sometimes leads to solutions in the Laplace domain that are not readily invertible to the real domain by analyticalmeans.Thus,we need numerical inversionmethods to convert the obtained solution fromLaplace domain to a real domain.In this paper,we propose a numerical scheme based on Laplace transform and numerical inverse Laplace transform for the approximate solution of fractal-fractional differential equations with orderα,β.Our proposed numerical scheme is based on three main steps.First,we convert the given fractal-fractional differential equation to fractional-differential equation in Riemann-Liouville sense,and then into Caputo sense.Secondly,we transformthe fractional differential equation in Caputo sense to an equivalent equation in Laplace space.Then the solution of the transformed equation is obtained in Laplace domain.Finally,the solution is converted into the real domain using numerical inversion of Laplace transform.Three inversion methods are evaluated in this paper,and their convergence is also discussed.Three test problems are used to validate the inversion methods.We demonstrate our results with the help of tables and figures.The obtained results show that Euler’s and Talbot’s methods performed better than Stehfest’s method. 展开更多
关键词 Fractal-fractional differential equation power law kernel exponential decay kernel Mittag-Leffler kernel Laplace transform Euler’s method Talbot’s method stehfest’s method
下载PDF
Effects of Cultivation Method on Seed Yield and Quality of Bitter Gourd 被引量:1
13
作者 Tianzhu ZHANG Caixia LIU +1 位作者 Zhiqiang MI Xueyuan ZHANG 《Asian Agricultural Research》 2020年第1期53-57,61,共6页
This experiment was carried out to study the possibility of producing germinating seeds of bitter gourd(Momordica charamtia L.)in the climatic conditions of Europe.Seeds of Indian cultivar‘Nana’were sown in the gree... This experiment was carried out to study the possibility of producing germinating seeds of bitter gourd(Momordica charamtia L.)in the climatic conditions of Europe.Seeds of Indian cultivar‘Nana’were sown in the greenhouse and produced transplants were planted on the field.The plants were cultivated in the field in 2 ways:tied to the sticks or creeping on the ground.During the vegetation,the ripen fruits with seeds were collected 6 times,and after extracting,they were germinated in the laboratory following the routine ISTA rules.The best transplants of bitter gourd were received within one month from the seeds emerging 51.8%.The transplant of bitter gourd had average height of7 cm,3-4 leaves,out of which the biggest had the width of 5 cm.Such transplants would grow into fruiting plants.When growing bitter gourd for seeds,the earliest fruits were harvested from the plants tied to the sticks.Moreover,the best seeds were harvested from 2/3 of early fruits.For the purpose of seed production,it is recommended to keep only 3-4 fruits per plant and remove other fruits.The produced seeds germinated from 8%to 24%.If the plants were tied to the sticks,their fruits ripened earlier.The used production way and time of harvest of fruits had no effect on the seed germination.The cultivation methods of bitter gourd plants had no effect on the chemical components of fruits. 展开更多
关键词 BITTER gourd seeds EUROPE CULTIVATION method
下载PDF
A Rapid Method for Measuring Seed Protein Content in Cowpea (<i>Vigna unguiculata</i>(L.) Walp) 被引量:1
14
作者 Yuejin Weng Ainong Shi +5 位作者 Waltram Second Ravelombola Wei Yang Jun Qin Dennis Motes David Octor Moseley Pengyin Chen 《American Journal of Plant Sciences》 2017年第10期2387-2396,共10页
Cowpea (Vigna unguiculata (L.) Walp), a legume crop that is grown in the worldwide, provides beneficial proteins for human consumption and animal feeding. In comparison, Rapid N analyzer as traditional method, has bee... Cowpea (Vigna unguiculata (L.) Walp), a legume crop that is grown in the worldwide, provides beneficial proteins for human consumption and animal feeding. In comparison, Rapid N analyzer as traditional method, has been widely used to measure protein content through the percentage of total nitrogen in the seed’s grounded powder. Near-Infrared Reflectance (NIR) has commonly been used to measure protein content in soybean seeds using whole grain without the need of seed grinding, which makes it possible to obtain fast results at a lower cost-per-analysis than the traditional combustion method. The specific objective of this study is to test a rapid method for measuring cowpea seed protein content by the NIR analyzer comparing to the traditional rapid N analyzer. A total of 240 cowpea genotypes were used in this study, including six seed coat colors, black, blackeye, browneye, cream, pinkeye, and red with 40 cowpea genotypes. The results showed that a linear relationship exists between the NIR analyzer and the Rapid N analyzer in the six different color groups. The correlation efficiency (r) between the seed protein contents from NIR and Rapid N was higher for pinkeye seed (r = 0.867), blackeye (0.771), cream (0.729), browneye (0.700), and red (0.623), respectively, but lower for black seeds, indicating that the NIR analyzer can be used to measure protein content for cowpea seeds with the five types of seed coat except black. Overview, the cowpea seed protein content measured from the NIR analyzer showed a little higher seed protein content. A series of regression models with different seed coat color have been built to adjust to protein content of colorful cowpea seeds from the NIR analyzer. But, it is not recommended to use for black color seeds due to a very low correlation efficiency (r) value with 0.184. 展开更多
关键词 COWPEA seed PROTEIN CONTENT PROTEIN Measurement method Rapid N ANALYZER Near-Infrared Reflectance (NIR) Vigna unguiculata
下载PDF
Establishment and Application of Identification Methods for Resistance to Sugarcane White Leaf Disease(SCWL)
15
作者 Wenfeng LI Rongyue ZHANG +4 位作者 Xiaoyan WANG Hongli SHAN Jie LI Yinhu LI Yingkun HUANG 《Agricultural Biotechnology》 CAS 2023年第1期12-15,共4页
[Objectives]This study was conducted to establish simple, efficient, stable, standardized and practical identification methods for sugarcane resistance to white leaf disease(SCWL), and promote the breeding for sugarca... [Objectives]This study was conducted to establish simple, efficient, stable, standardized and practical identification methods for sugarcane resistance to white leaf disease(SCWL), and promote the breeding for sugarcane resistance to SCWL. [Methods]The identification technology of sugarcane resistance to SCWL was systematically studied and explored from the aspects of sugarcane material treatment and planting, inoculation liquid preparation, inoculation method, disease investigation, grading standard formulation, etc., and two sets of simple, efficient, stable, standardized and practical accurate identification methods for sugarcane resistance to SCWL were created for the first time, namely, the seed cane coating inoculation method and the stem-cutting inoculation method at the growth stage. The seed cane coating inoculation method includes the steps of directly screening SCWL phytoplasma, extracting juice from cane and adding 10 times of sterile water to prepare an inoculation liquid, spraying seed cane on plastic film to keep moisture, planting the inoculated materials in barrels in an insect-proof greenhouse for cultivation, investigating the incidence rate 30 d after inoculation, and evaluating the disease resistance according to the 1-5 level standard. The method of stem-cutting inoculation includes the steps of directly screening sugarcane stems carrying SCWL phytoplasma and adding 10 times of sterile water to prepare an inoculation liquid, cultivating the identification materials in an insect-proof greenhouse, dropping 100 μl of the inoculation liquid into each root incision with a pipette gun at the age of 6 months, investigating the incidence rate 20 d after planting, and evaluating the disease resistance according to the 1-5 level standard. [Results] The two methods are similar to the natural transmission method. After inoculation, SCML occurred significantly, with high sensitivity and good reproducibility. The results of resistance identification were consistent with those of natural disease in the field. Through the two inoculation methods and field natural disease investigation, the resistance of 10 main cultivars to SCML was identified, which was true and reliable. [Conclusions] This study can provide standard varieties for identification of SCML resistance in the future. 展开更多
关键词 sugarcane white leaf disease Inoculation technology seed cane-spraying inoculation stem-cutting inoculation method Identification of disease resistance
下载PDF
Stochastic Programming for Hub Energy Management Considering Uncertainty Using Two-Point Estimate Method and Optimization Algorithm
16
作者 Ali S.Alghamdi Mohana Alanazi +4 位作者 Abdulaziz Alanazi Yazeed Qasaymeh Muhammad Zubair Ahmed Bilal Awan M.G.B.Ashiq 《Computer Modeling in Engineering & Sciences》 SCIE EI 2023年第12期2163-2192,共30页
To maximize energy profit with the participation of electricity,natural gas,and district heating networks in the day-ahead market,stochastic scheduling of energy hubs taking into account the uncertainty of photovoltai... To maximize energy profit with the participation of electricity,natural gas,and district heating networks in the day-ahead market,stochastic scheduling of energy hubs taking into account the uncertainty of photovoltaic and wind resources,has been carried out.This has been done using a new meta-heuristic algorithm,improved artificial rabbits optimization(IARO).In this study,the uncertainty of solar and wind energy sources is modeled using Hang’s two-point estimating method(TPEM).The IARO algorithm is applied to calculate the best capacity of hub energy equipment,such as solar and wind renewable energy sources,combined heat and power(CHP)systems,steamboilers,energy storage,and electric cars in the day-aheadmarket.The standard ARO algorithmis developed to mimic the foraging behavior of rabbits,and in this work,the algorithm’s effectiveness in avoiding premature convergence is improved by using the dystudynamic inertia weight technique.The proposed IARO-based scheduling framework’s performance is evaluated against that of traditional ARO,particle swarm optimization(PSO),and salp swarm algorithm(SSA).The findings show that,in comparison to previous approaches,the suggested meta-heuristic scheduling framework based on the IARO has increased energy profit in day-ahead electricity,gas,and heating markets by satisfying the operational and energy hub limitations.Additionally,the results show that TPEM approach dependability consideration decreased hub energy’s profit by 8.995%as compared to deterministic planning. 展开更多
关键词 stochastic energy hub scheduling energy profit UNCERTAINTY Hong’s two-point estimate method improved artificial rabbits optimization
下载PDF
基于S-R和分解定理的二维几何非线性问题的虚单元法求解
17
作者 江巍 尹豪 +3 位作者 吴剑 汤艳春 李坤鹏 郑宏 《工程力学》 EI CSCD 北大核心 2024年第8期23-35,共13页
应变-旋转(Strain-Rotation,S-R)和分解定理为分析几何非线性问题提供了合理可靠的理论基础,但用有限元求解时会遇到大变形发生后的网格畸变问题。近年提出的虚单元法(Virtual element method,VEM)适用于一般的多边形网格,因此,该文尝... 应变-旋转(Strain-Rotation,S-R)和分解定理为分析几何非线性问题提供了合理可靠的理论基础,但用有限元求解时会遇到大变形发生后的网格畸变问题。近年提出的虚单元法(Virtual element method,VEM)适用于一般的多边形网格,因此,该文尝试使用一阶虚单元求解基于S-R和分解定理的二维几何非线性问题,以克服网格畸变的影响。基于重新定义的多项式位移空间基函数,推演获得一阶虚单元分析线弹性力学问题时允许位移空间向多项式位移空间的投影表达式;按照虚单元法双线性格式的计算规则,分析处理基于更新拖带坐标法和势能率原理的增量变分方程;进而建立离散系统方程及其矩阵表达形式,并编制MATLAB求解程序;采用常规多边形网格和畸变网格,应用该文算法分析均布荷载下的悬臂梁和均匀内压下的厚壁圆筒变形。结果与已有文献和ANSYS软件的对比表明:该文算法在两种网格中均可有效执行且具备足够数值精度。总体该文算法为基于S-R和分解定理的二维几何非线性问题求解提供了一种鲁棒方法。 展开更多
关键词 s-R和分解定理 虚单元法 几何非线性 网格畸变 多边形网格
下载PDF
Technology of Extracting Kiwi Fruit Seed Oil with Ultrasonic-Assisted Enzyme and Response Surface Method 被引量:1
18
作者 Zhi Zhang Mengting Pan Dongmin Liu 《Food and Nutrition Sciences》 2016年第9期807-816,共11页
Taken kiwi fruit as raw material, this paper extracted kiwi fruit seed oil with ultrasonic-assisted enzyme, researched the influence of factors such as liquid-to-solid ratio, granularity, type of enzyme, ultrasonic po... Taken kiwi fruit as raw material, this paper extracted kiwi fruit seed oil with ultrasonic-assisted enzyme, researched the influence of factors such as liquid-to-solid ratio, granularity, type of enzyme, ultrasonic power, treating time, enzymolysis temperature, enzymolysis time, pH and enzyme additive on oil extraction, and optimized the extracting technology of kiwi fruit seed oil with response surface method. The result shows that the best technical parameter is: material granularity: 60, liquid-to-solid ratio: 1:10 (g/mL), ultrasonic power: 400 W, treating time: 30 min, enzyme amount: 2.50%, pH: 9.2, enzymolysis temperature: 53&deg;C, enzymolysis time: 2.80 h;and the extracting ratio under such condition is 92.57%. 展开更多
关键词 Kiwi Fruit seed Oil Ultrasonic Wave Aqueous Enzymatic method
下载PDF
Establishment of Molecular Biological Method for Identification of Bacteria by 16S rDNA and gyrB Gene
19
作者 Xiaxia HOU Yunxia WANG +1 位作者 Cuizhi LI Zhiyong LU 《Asian Agricultural Research》 2023年第4期21-25,共5页
[Objectives]The paper was to establish a molecular biological method for identification of bacterial strains.[Methods]The thalli of standard bacterial strains existing in the laboratory were collected and genomic DNA ... [Objectives]The paper was to establish a molecular biological method for identification of bacterial strains.[Methods]The thalli of standard bacterial strains existing in the laboratory were collected and genomic DNA was extracted for amplification of 16S rDNA and gyrB gene.The 16S rDNA and gyrB gene sequences were obtained after sequencing.Sequences were aligned and analyzed via EzBioCloud and NCBI database,and phylogenetic trees were constructed to determine the species relationship of strains.Meantime,they were compared with known strains.[Results]This method could identify 5 standard strains accurately to the species level.The 16S rDNA and gyrB gene sequences were aligned and analyzed in EzBioCloud database and NCBI database.The strain with the max score was consistent with the known strain.And the query cover and ident were both above 99%.[Conclusions]The established molecular biological method for identification of bacterial strains by 16S rDNA and gyrB gene has good accuracy,which effectively solves the problem that the laboratory identification of bacteria relies on traditional methods and the accuracy can not be guaranteed,and further improves the identification ability of laboratory bacterial strains. 展开更多
关键词 16s rDNA GYRB Bacterial identification Molecular biological method
下载PDF
ASD与非ASD语言发育迟缓儿童的语言行为能力差异分析
20
作者 陈玉美 胡丽娜 牟志伟 《广东医学》 CAS 2024年第6期661-665,共5页
目的通过比较孤独症谱系障碍(autism spectrum disorder,ASD)与非ASD语言发育迟缓儿童的各项语言行为能力,分析两者的特征差异。方法回顾收集2020年1月至2022年12月就诊的确诊为ASD(98例)和非ASD(122例)语言发育迟缓儿童的年龄、性别、... 目的通过比较孤独症谱系障碍(autism spectrum disorder,ASD)与非ASD语言发育迟缓儿童的各项语言行为能力,分析两者的特征差异。方法回顾收集2020年1月至2022年12月就诊的确诊为ASD(98例)和非ASD(122例)语言发育迟缓儿童的年龄、性别、ABC量表和S-S量表得分资料,对两组儿童的结果先进行单因素分析,对单因素分析有统计学差异的项目进行多因素二元logistic回归分析。结果经单因素分析,两组儿童年龄无统计学差异,其他项目包括性别,S-S交流态度能力、S-S操作性课题能力、S-S语言理解能力、S-S语言表达能力和ABC总分均有统计学差异(均P<0.05)。采用输入法把两组有差异的性别、S-S交流态度能力、S-S操作性课题能力、S-S语言理解能力、S-S语言表达能力和ABC总分共6个项目进行多因素二元logistic回归分析,结果表明S-S交流态度能力和ABC总分两个项目是区分两组儿童的独立影响因素(均P<0.05),S-S交流态度不良和ABC总分高均是危险因素。结论S-S交流态度能力和ABC总分是区分ASD和非ASD语言发育迟缓儿童的独立影响因素,临床上对于S-S交流态度不良及ABC总分高的语言发育迟缓儿童要高度警惕是否ASD儿童。 展开更多
关键词 孤独症谱系障碍 语言发育迟缓 s-s评估法 ABC量表 LOGIsTIC回归
下载PDF
上一页 1 2 250 下一页 到第
使用帮助 返回顶部