期刊文献+
共找到9篇文章
< 1 >
每页显示 20 50 100
基于动量梯度下降的回声消除算法
1
作者 陈张良 卢敏 曾桂根 《现代电子技术》 北大核心 2024年第9期71-77,共7页
针对极端环境话音系统下声学回波影响工作人员正常施工,且常规声学回声消除算法收敛速度慢的问题,提出一种基于动量梯度下降的基于l0范数的改进系数成比例归一化最小均方误差算法(L0⁃IPNLMS)。该算法将动量因子引入L0⁃IPNLMS算法中,解... 针对极端环境话音系统下声学回波影响工作人员正常施工,且常规声学回声消除算法收敛速度慢的问题,提出一种基于动量梯度下降的基于l0范数的改进系数成比例归一化最小均方误差算法(L0⁃IPNLMS)。该算法将动量因子引入L0⁃IPNLMS算法中,解决在算法运行过程中梯度下降时梯度摆动幅度可能过大的问题,也提高了自适应滤波器的收敛速度,且残余回声下降明显,声学回波抑制效果更好。仿真实验表明,与L0⁃IPNLMS算法相比,新算法在模拟随机多音信号与真实语音信号输入时,均方误差(MSE)可以降低3.47 dB和3.69 dB,回波抑制比(ERLE)提高了3.46 dB和3.68 dB,在低信噪比情况下,使用新算法对真实语音信号进行回声消除,收敛速度高于L0⁃IPNLMS等算法,且收敛效果有明显改进。 展开更多
关键词 回声消除算法 动量梯度下降 极端环境话音通信系统 归一化 最小均方算法 收敛速度
下载PDF
基于GRA-SPA耦合模型的煤矿充填系统稳定性评判 被引量:4
2
作者 史俊伟 陈章良 +1 位作者 吴昌友 沈盈盈 《中国安全科学学报》 CAS CSCD 北大核心 2018年第4期97-102,共6页
为预防煤矿充填系统运行安全事故,综合运用灰色关联分析法(GRA)和集对分析法(SPA),研究煤矿充填系统稳定性。首先,建立充填系统稳定性评判指标体系,并采用AHP法确定各指标权重;然后,构建GRA-SPA耦合评判模型,通过将评价集与指标集... 为预防煤矿充填系统运行安全事故,综合运用灰色关联分析法(GRA)和集对分析法(SPA),研究煤矿充填系统稳定性。首先,建立充填系统稳定性评判指标体系,并采用AHP法确定各指标权重;然后,构建GRA-SPA耦合评判模型,通过将评价集与指标集建立集对、计算其绝对关联度及综合联系度来确定评价对象等级,并预测其发展趋势;最后,以某矿充填系统为例,用所建模型评判其稳定性。结果表明:该矿充填系统稳定性等级为较稳定,且有向好的方向发展的趋势,但不明显,仍需引起重视。该模型能够将充填系统各指标因子的同一性、差异性和对立性通过联系度系数定量化,得到与实际情况相一致的评判结论,为煤矿充填开采安全管理提供参考。 展开更多
关键词 煤矿 充填开采 充填系统 灰色关联(GRA) 集对分析(SPA) 稳定性评判
下载PDF
高校混合式教学改革研究及效果评价——以工程制图及CAD课程为例 被引量:12
3
作者 史俊伟 陈章良 +2 位作者 刘刚 李立峰 董羽 《中国教育技术装备》 2017年第16期114-117,共4页
以工程制图及CAD课程为例,以清华教育在线研制的优慕课"在线教育综合平台"之"山东工商学院网络教学平台"为依托,从课程内容设计、课程教学设计、课程教学考评方式三个方面,进行信息化教学模式下课程教学改革的探索... 以工程制图及CAD课程为例,以清华教育在线研制的优慕课"在线教育综合平台"之"山东工商学院网络教学平台"为依托,从课程内容设计、课程教学设计、课程教学考评方式三个方面,进行信息化教学模式下课程教学改革的探索。并应用层次分析法(AHP)建立各指标权重,利用模糊综合评价法(FCE)进行多层次综合评价,对信息技术环境下的混合式教学改革效果进行有效分析评估,由评价结果可知:混合式教学模式效果为"良好",学生调查问卷显示,学生对课程混合式教学的满意度为80.81%,与评价结果相符。 展开更多
关键词 工程制图 CAD课程 混合式教学模式 信息技术
下载PDF
开滦集团东欢坨矿通风阻力测定与分析 被引量:2
4
作者 陈章良 张坤 邵良杉 《煤矿现代化》 2022年第6期18-20,25,共4页
为获取矿井阻力分布情况,进一步改善优化矿井通风系统,减少通风阻力,同时为降低矿井通风机的电耗以及均压防灭火提供依据。采用气压计基点测定法对开滦集团东欢坨矿进行通风阻力测定。通过对测定数据的计算分析,总体上矿井通风系统阻力... 为获取矿井阻力分布情况,进一步改善优化矿井通风系统,减少通风阻力,同时为降低矿井通风机的电耗以及均压防灭火提供依据。采用气压计基点测定法对开滦集团东欢坨矿进行通风阻力测定。通过对测定数据的计算分析,总体上矿井通风系统阻力分布基本合理,矿井总风阻及等积孔为0.0364 N·s^(2)/m^(8)和6.2372 m^(2),为通风容易型矿井。 展开更多
关键词 矿井通风 阻力分布 矿井等积孔 气压计基点测定法
下载PDF
卡拉胶/琼脂/羟丙基-β-环糊精复合凝胶的合成及其载药性能研究 被引量:1
5
作者 张波 苏衍华 +3 位作者 庞丽艳 陈章良 李兆楼 王凤琴 《济宁医学院学报》 2020年第4期242-247,共6页
目的利用卡拉胶(KC)、琼脂(Agar)和羟丙基-β-环糊精(HP-β-CD)合成新型复合凝胶,探索其外观、微观结构、物理化学性质及载药性能。方法采用溶胶-凝胶法合成KC/Agar/HP-β-CD复合凝胶,光学显微镜、扫描电子显微镜、红外光谱、X射线衍射(... 目的利用卡拉胶(KC)、琼脂(Agar)和羟丙基-β-环糊精(HP-β-CD)合成新型复合凝胶,探索其外观、微观结构、物理化学性质及载药性能。方法采用溶胶-凝胶法合成KC/Agar/HP-β-CD复合凝胶,光学显微镜、扫描电子显微镜、红外光谱、X射线衍射(XRD)等观测其结构、性质、性能;载药凝胶包封率、体外释放等实验考察其对药物的缓控释作用。结果制备了新型的KC/Agar/HP-β-CD复合凝胶及其载药凝胶,该凝胶性质稳定,载药凝胶包封率为50.29%;凝胶体系加入HP-β-CD,能使甲氨蝶呤载药凝胶的释药率降低约10%。结论新型KC/Agar/HP-β-CD复合凝胶合成方法简便、成本较低,且对药物具有较高的包封率及明显缓控释作用。 展开更多
关键词 卡拉胶 琼脂 羟丙基-Β-环糊精 复合凝胶 体外释放 甲氨蝶呤
下载PDF
Construction of chimeric inducible promoters by elicitors of rice fungal blast pathogen and their expression in transgenic rice 被引量:5
6
作者 LU Huafei MING Xiaotian +4 位作者 QU Lijia LIU Meihua LI Jing GU Hongya chen zhangliang 《Chinese Science Bulletin》 SCIE EI CAS 2000年第3期242-246,共5页
The promoter fragments of wheat GstA1 and potato Gst1 have been amplified by PCR, cloned and fused respectively to the minimal promoter sequence of rice actin gene (Act1)) and its 5’ untranslated leader sequence toge... The promoter fragments of wheat GstA1 and potato Gst1 have been amplified by PCR, cloned and fused respectively to the minimal promoter sequence of rice actin gene (Act1)) and its 5’ untranslated leader sequence together with GUS. The constructs with 2 chimeric promoters (WGA and PGA) have been transferred into rice in order to analyze their inducibility patterns in transgenic rice plants. The results show that: WGA and PGA are both inducible by elicitors of Pyricularia oryzae in transgenic rice cells; the intron I of rice Act1 gene is important for the heterogenic expression of monocot and dicot promoter elements in rice; and the Act1 minimal promoter and its 5’untranslated leader sequence produced low level background expression in rice. 展开更多
关键词 pathogen-inducible CHIMERIC promoter gene EXPRESSION and regulation transgenic RICE RICE FUNGAL BLAST disease.
原文传递
Molecular evolution of the exon 2 of CHS genes and the possibility of its application to plant phylogenetic analysis 被引量:6
7
作者 WANG Jinling QU Lijia +2 位作者 chen Jun GU Hongya chen zhangliang 《Chinese Science Bulletin》 SCIE EI CAS 2000年第19期1735-1742,共8页
The exon 2 of chalcone synthase (CHS) gene is relatively conserved during evolution. In this study, three exon 2 fragments from two species in gymnosperm (Cycas panzhihuaensis, Ginkgo biloba ) and seven from four spec... The exon 2 of chalcone synthase (CHS) gene is relatively conserved during evolution. In this study, three exon 2 fragments from two species in gymnosperm (Cycas panzhihuaensis, Ginkgo biloba ) and seven from four species in angiosperm (Magnolia denudata, Salix babylonica, Nymphaea tetragona, Camellia japonica) have been amplified by PCR from genomic DNA and sequenced. Together with other 73 sequences of CHS collected from EMBL database and literature, these sequences, which embrace 19 families of gymnosperm and angiosperm, have been analyzed for their phylogenetic relations by parsimony method. The result indicated that sequences from the same systematic family usually grouped together except those from Theaceae, Magnoliaceae and Nymphaeaceae. The relative rate test revealed the rate heterogeneity of CHS genes among the families. For the nucleotide substitution the sequences from Asteraceae and Solanaceae evolve faster than those from the other families analyzed while the sequences from Poaceae, 展开更多
关键词 CHALCONE SYNTHASE (CHS) PCR PHYLOGENY molecular evolution.
原文传递
Expression and inhibitory activity analysis of a 25-kD Bowman-Birk protease inhibitor in rice 被引量:2
8
作者 chen Jun MAO Shengji +6 位作者 XlE Yang CAO Zhongren ZHANG Yan LIU jing chen zhangliang QU Lijia GU Hongya 《Chinese Science Bulletin》 SCIE EI CAS 2006年第1期54-62,共9页
Rice Bowman-Birk inhibitors (RBBI), with one (8 kD) or two homologous domains (16 kD), were found to be effective trypsin inhibitors in vitro. In this study, we demonstrate that the 25-kD protein corresponding to the ... Rice Bowman-Birk inhibitors (RBBI), with one (8 kD) or two homologous domains (16 kD), were found to be effective trypsin inhibitors in vitro. In this study, we demonstrate that the 25-kD protein corresponding to the three-domain RBBI indeed ex- ists in rice in planta, and that the RBBIs are regulated by development and wounding. We also found by inhibitory activity assay that the 3:13 disulfide bond, but not the 4:5 disulfide bond, suppresses the tryp- sin-inhibitory activity, and the D3 domain of RBBI3-1 has no inhibitory activity against trypsin, chymotryp- sin, paparin or subtilisin. Mutation analyses showed that conversion from Lys to Leu or Tyr in the N-terminal P1 site in D1 domain did not create chy- motrypsin-inhibitory activity, suggesting that the structure of the reactive loop in D1 domain hinder the new inhibitory specificity at P1 site, and the chy- motrypsin-inhibitory activity might need the participa- tion of other structures, e.g. 3:13 disulfide bond. 展开更多
关键词 水稻 RBBI 双硫键 胰凝乳蛋白酶 胰岛素
原文传递
Cloning and expression of a cDNA encoding ribosomal protein S4 from Rice (Oryza sativa)
9
作者 QU Lijia LI Donghui +3 位作者 ZHANG Yi LIU Meihua GU Hongya chen zhangliang 《Chinese Science Bulletin》 SCIE EI CAS 2000年第2期168-173,共6页
A cDNA clone, pS4, has been isolated from a cDNA library prepared from rice anthers of about 1.0 mm in length. DNA sequence analysis and database search show that the cDNA encodes a protein which is highly homologous ... A cDNA clone, pS4, has been isolated from a cDNA library prepared from rice anthers of about 1.0 mm in length. DNA sequence analysis and database search show that the cDNA encodes a protein which is highly homologous to eukaryotic 80S ribosomal protein subunit 4 (S4). Northern hybridization indicates that this gene expresses in all tissues analyzed although the expression level varies and it cannot be induced by mechanical wounding in leaves. Southern blot analysis demonstrates that this rice S4 gene is from a multigene 展开更多
关键词 RIBOSOMAL protein S4 cDNA CLONE monocotyledonous plant tissue specificity(rice) 1) The NUCLEOTIDE SEQUENCE data reported is in the EMBL NUCLEOTIDE SEQUENCE Database under the ACCESSION number Y15009.
原文传递
上一页 1 下一页 到第
使用帮助 返回顶部