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The Cumulative Method for Multiplication and Division
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作者 Muna Mohammed Hammuda 《Applied Mathematics》 2024年第5期349-354,共6页
This paper provides a method of the process of computation called the cumulative method, it is based upon repeated cumulative process. The cumulative method is being adapted to the purposes of computation, particularl... This paper provides a method of the process of computation called the cumulative method, it is based upon repeated cumulative process. The cumulative method is being adapted to the purposes of computation, particularly multiplication and division. The operations of multiplication and division are represented by algebraic formulas. An advantage of the method is that the cumulative process can be performed on decimal numbers. The present paper aims to establish a basic and useful formula valid for the two fundamental arithmetic operations of multiplication and division. The new cumulative method proved to be more flexible and made it possible to extend the multiplication and division based on repeated addition/subtraction to decimal numbers. 展开更多
关键词 Multiplication and division Cumulative Method Repeated Process Decimal Numbers
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Machine learning solution for regional landslide susceptibility based on fault zone division strategy
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作者 WANG Yunhao WANG Luqi +5 位作者 LIU Songlin SUN Weixin LIU Pengfei ZHU Lin YANG Wenyu GUO Tong 《Journal of Mountain Science》 SCIE CSCD 2024年第5期1745-1760,共16页
Landslide susceptibility assessment is an essential tool for disaster prevention and management. In areas with multiple fault zones, the impact of fault zone on slope stability cannot be disregarded. This study perfor... Landslide susceptibility assessment is an essential tool for disaster prevention and management. In areas with multiple fault zones, the impact of fault zone on slope stability cannot be disregarded. This study performed qualitative analysis of fault zones and proposed a zoning method to assess the landslide susceptibility in Chengkou County, Chongqing Municipality, China. The region within a distance of 1 km from the faults was designated as sub-zone A, while the remaining area was labeled as sub-zone B. To accomplish the assessment, a dataset comprising 388 historical landslides and 388 non-landslide points was used to train the random forest model. 10-fold cross-validation was utilized to select the training and testing datasets for the model. The results of the models were analyzed and discussed, with a focus on model performance and prediction uncertainty. By implementing the proposed division strategy based on fault zone, the accuracy, precision, recall, F-score, and AUC of both two sub-zones surpassed those of the whole region. In comparison to the results obtained for the whole region, sub-zone B exhibited an increase in AUC by 6.15%, while sub-zone A demonstrated a corresponding increase of 1.66%. Moreover, the results of 100 random realizations indicated that the division strategy has little effect on the prediction uncertainty. This study introduces a novel approach to enhance the prediction accuracy of the landslide susceptibility mapping model in areas with multiple fault zones. 展开更多
关键词 Landslide susceptibility mapping Fault division strategy Random forest GIS
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Cell division cyclin 25C knockdown inhibits hepatocellular carcinoma development by inducing endoplasmic reticulum stress
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作者 Yan-Fei Li Fang-Yuan Zheng +4 位作者 Xin-Yu Miao Hai-Long Liu Yao-Yao Zhang Nai-Xia Chao Fa-Rong Mo 《World Journal of Gastroenterology》 SCIE CAS 2024年第19期2564-2574,共11页
BACKGROUND Cell division cyclin 25C(CDC25C)is a protein that plays a critical role in the cell cycle,specifically in the transition from the G2 phase to the M phase.Recent research has shown that CDC25C could be a pot... BACKGROUND Cell division cyclin 25C(CDC25C)is a protein that plays a critical role in the cell cycle,specifically in the transition from the G2 phase to the M phase.Recent research has shown that CDC25C could be a potential therapeutic target for cancers,particularly for hepatocellular carcinoma(HCC).However,the specific regulatory mechanisms underlying the role of CDC25C in HCC tumorigenesis and development remain incompletely understood.AIM To explore the impact of CDC25C on cell proliferation and apoptosis,as well as its regulatory mechanisms in HCC development.METHODS Hepa1-6 and B16 cells were transduced with a lentiviral vector containing shRNA interference sequences(LV-CDC25C shRNA)to knock down CDC25C.Subsequently,a xenograft mouse model was established by subcutaneously injecting transduced Hepa1-6 cells into C57BL/6 mice to assess the effects of CDC25C knockdown on HCC development in vivo.Cell proliferation and migration were evaluated using a Cell Counting Kit-8 cell proliferation assays and wound healing assays,respectively.The expression of endoplasmic reticulum(ER)stress-related molecules(glucose-regulated protein 78,X-box binding protein-1,and C/EBP homologous protein)was measured in both cells and subcutaneous xenografts using quantitative real-time PCR(qRT-PCR)and western blotting.Additionally,apoptosis was investigated using flow cytometry,qRT-PCR,and western blotting.RESULTS CDC25C was stably suppressed in Hepa1-6 and B16 cells through LV-CDC25C shRNA transduction.A xenograft model with CDC25C knockdown was successfully established and that downregulation of CDC25C expression significantly inhibited HCC growth in mice.CDC25C knockdown not only inhibited cell proliferation and migration but also significantly increased the ER stress response,ultimately promoting ER stress-induced apoptosis in HCC cells.CONCLUSION The regulatory mechanism of CDC25C in HCC development may involve the activation of ER stress and the ER stress-induced apoptosis signaling pathway. 展开更多
关键词 Cell division cyclin 25C Hepatocellular carcinoma Endoplasmic reticulum stress PROLIFERATION Apoptosis
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Structural characteristics and tectonic division of the Zambezi Delta basin in the offshore East Africa:evidences from gravity and seismic data
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作者 Guozhang Fan Wen Li +8 位作者 Liangbo Ding Wanyin Wang Hongping Wang Dingding Wang Lin Li Hao Wang Chaofeng Wang Qingluan Wang Ying Zhang 《Acta Oceanologica Sinica》 SCIE CAS CSCD 2024年第4期105-118,共14页
The Zambezi Delta basin is a passive marginal basin located on the East African coast that has good oil and gas exploration potential.Due to the special geological evolutionary background of the Beira High in the Zamb... The Zambezi Delta basin is a passive marginal basin located on the East African coast that has good oil and gas exploration potential.Due to the special geological evolutionary background of the Beira High in the Zambezi Delta basin,it has a low gravity anomaly,and the existing seismic survey lines do not cover the whole basin;therefore,it is difficult to interpret the structural characteristics of the whole basin based solely on gravity or seismic data.Based on satellite altimetry gravity anomaly data,this study infers the distribution characteristics of faults in the Zambezi Delta basin by using the normalized vertical derivative of the total horizontal derivative(NVDR-THDR)technique.Then,constrained by seismic data,the gravity anomaly at the Moho interface is extracted by using the fast forward method of the double-interface model of the gravity anomaly,and this anomaly is then removed from the Bouguer gravity anomaly to obtain the sedimentary layer gravity anomaly.The thickness of the sedimentary strata is obtained by inversing the sedimentary basement depth of the whole basin.Then,uplifts and depressions are divided based on a sedimentary layer thickness of 3 km.This research demonstrates that the Zambezi Delta basin mainly features nearly SN-trending and NE-trending faults and that these faults exhibit east-west partitioning.The nearly SN-trending strike-slip faults controlled the sedimentary development of the basin,and the NE-trending tensile faults may have acted as migration channels for oil,gas and magma.The“overcompensation”effect of the Moho interface gravity anomaly on the gravity anomaly of the sedimentary layer is caused by the depression of the Moho interface beneath the Beira High,which results in a low gravity anomaly value for the Beira High.The pattern of uplifts and depressions trends NE and has the structural characteristics of east-west blocks. 展开更多
关键词 Zambezi Delta basin satellite altimetry gravity anomaly Beira High fault division uplift and depression pattern
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Residual Film Pollution in the Eighth Division of the Xinjiang Production and Construction Corps
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作者 Weijun LI Xingyao ZHANG +3 位作者 Nate KA Xianglin YANG Jianjiang LU Xuyun ZHANG 《Research and Application of Materials Science》 2023年第1期11-16,共6页
This study investigated the residual film content and distribution at different soil depths in the Eighth Division of the Xinjiang Production and Construction Corps.Before spring plowing in 2019,representative fields ... This study investigated the residual film content and distribution at different soil depths in the Eighth Division of the Xinjiang Production and Construction Corps.Before spring plowing in 2019,representative fields in four areas(Anjihai,Shihezi suburbs,Mosuowan and Xiayedi)were selected for residual film collection.The average content of residual film in the Eighth Division was 104 kg/ha.The residual film content in the four areas decreased in the order Anjihai>Shihezi suburbs>Mosuowan>Xiayedi.The average amount of residual film collected from cotton fields was greater than that from corn fields.Residual film content in the cotton field at soil depths of 0~10 and 10~30 cm was higher than that in the corn field,whereas the residual film content at a 30–50 cm soil depth in the corn field was higher than that in the cotton field.The results showed that farmers do not consider the long-term benefits,the high cost and short time of recycling,and the easy recycling of surface residual film.The shallow that the higher content of residual film,the less water in the soil of cotton.The same time,the results showed that the quantity of residual film in cotton field had greater influence on cotton quality. 展开更多
关键词 Eighth division Residual film POLLUTION Present situation PROBLEMS
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蓖麻Lm型雌性系及其杂交组合的杂种优势分析
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作者 周伟 余忠浩 +1 位作者 刘慧 周亚星 《西北农业学报》 CAS CSCD 北大核心 2024年第7期1274-1281,共8页
为了解Lm型雌性系蓖麻的配合力遗传基础,以5个蓖麻Lm型雌性系为母本,3个蓖麻两性系为父本,根据NC-Ⅱ不完全双列杂交组配15个杂交组合,对蓖麻杂交组合的配合力、遗传力以及杂种优势进行分析。结果表明:雌性系A1和两性系B2的GCA和杂交组合... 为了解Lm型雌性系蓖麻的配合力遗传基础,以5个蓖麻Lm型雌性系为母本,3个蓖麻两性系为父本,根据NC-Ⅱ不完全双列杂交组配15个杂交组合,对蓖麻杂交组合的配合力、遗传力以及杂种优势进行分析。结果表明:雌性系A1和两性系B2的GCA和杂交组合SCA在蓖麻大部分农艺性状中均表现优秀,可在提高蓖麻产量的亲本选育中作为优异亲本进行杂交组合的构建。对亲本杂种优势研究发现,两性系B2参与组配的杂交组合在多个农艺性状上表现为强杂种优势,而Lm型雌性系则表现为在单个性状上具有较强的杂种优势。从遗传力分析结果来看,蓖麻的主茎蒴果数、一级分枝蒴果数、主茎穗长、主茎节数、一级分枝百粒质量和产量受加性效应和非加性效应共同影响,且受环境影响较小,适宜在早代进行选择。 展开更多
关键词 蓖麻 lm型雌性系 杂种优势 配合力 遗传力
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基于LM优化的车载全景影像绝对测量方法
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作者 曹君 叶辰萌 刘正华 《河南科技》 2024年第7期5-9,共5页
【目的】为解决车载全景影像在智慧城市、智慧城管、智慧交通等领域中应用不足的问题,提出了一种基于LM优化的车载序列全景影像绝对测量的方法。【方法】首先,对待测目标点在全景影像上的成像过程进行分析,详细推导了目标点绝对坐标测... 【目的】为解决车载全景影像在智慧城市、智慧城管、智慧交通等领域中应用不足的问题,提出了一种基于LM优化的车载序列全景影像绝对测量的方法。【方法】首先,对待测目标点在全景影像上的成像过程进行分析,详细推导了目标点绝对坐标测量的理论模型。其次,为解决该理论模型的优化求解问题,引入了对初值不敏感且收敛速度较快的LM算法,并对LM算法中的初值获取、函数构建、参数设置等问题进行了设计。最后,结合实际车载全景影像和目标点位实测数据,对所提的方法进行验证。【结果】该方法获得的目标点绝对坐标平面中误差和高程中误差分别为0.123 m和0.118 m,符合《城市测量规范》(CJJ/T 8—2011)中的相关要求。【结论】该方法能够有效获取全景影像范围内待测目标点的绝对坐标,从而为全景影像在城市部件普查、交通基础设施测量等领域的应用提供了可能。 展开更多
关键词 lm优化 车载 全景影像 绝对测量
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基于改进变步长LMS算法的谐波电流检测法
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作者 曹珍贯 方金明 董高辉 《佳木斯大学学报(自然科学版)》 CAS 2024年第4期19-23,共5页
针对传统基于瞬时无功功率理论谐波电流检测中的二阶低通滤波器无法同时满足检测精度和响应时间的问题,提出了基于改进的双曲正切函数变步长LMS算法(IVSSLMS)的低通滤波器提取p轴和q轴中直流分量的方法;将两个谐波电流的间隔时间通过适... 针对传统基于瞬时无功功率理论谐波电流检测中的二阶低通滤波器无法同时满足检测精度和响应时间的问题,提出了基于改进的双曲正切函数变步长LMS算法(IVSSLMS)的低通滤波器提取p轴和q轴中直流分量的方法;将两个谐波电流的间隔时间通过适当的调节采样间隔次数来延长,目的是为了达到高次谐波的自相关性能迅速降为零。从理论上分析了算法性能的优越,给出了参数的取值,并在simulink中搭建了仿真模型,仿真实验结果表明,改进后的低通滤波器直流分量的跟踪速度提升了一倍,得到基波正弦波形的THD值下降了0.37%。并得出以下结论:在同样输电条件下,采用改进变步长LMS算法构成低通滤波器加快了直流量的跟踪,提取的基波分量更加接近于理想波形,提升了谐波检测的瞬时性和准确性。 展开更多
关键词 瞬时无功理论 lmS算法 谐波总畸变率
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基于x-LMS算法的直升机主动消振电力作动器系统研究
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作者 郝振洋 杨健 +2 位作者 张嘉文 曹鑫 王涛 《Transactions of Nanjing University of Aeronautics and Astronautics》 EI CSCD 2024年第1期53-65,共13页
直升机前飞时,气动环境会导致不同方位角的桨叶出现气动载荷的瞬间不对称,通过基础结构传递会在机身形成大幅度的低频振动。为了消除多方向幅值变化的振动力,利用结构响应主动控制原理,设计了基于x-LMS算法的主动消振电力作动器系统,并... 直升机前飞时,气动环境会导致不同方位角的桨叶出现气动载荷的瞬间不对称,通过基础结构传递会在机身形成大幅度的低频振动。为了消除多方向幅值变化的振动力,利用结构响应主动控制原理,设计了基于x-LMS算法的主动消振电力作动器系统,并进行了减振实验。首先,通过比较确定了单台作动器中两台电机同向旋转的方案。通过两台作动器的组合使用,推导出输出力的数学模型。其次,采用负载相位差交叉耦合的控制策略设计系统控制框图。针对存在耦合的相位外环,通过回差阵特征值法确定满足系统稳定裕度要求的参数范围,再根据灵敏度函数和输入跟踪性能在所得的参数稳定域内寻找最优解。然后,提出了基于x-LMS算法的直升机主动振动控制系统,并通过仿真验证了该系统的减振效果。最后,研制的实验样机进行了动稳态实验以及减振实验,验证了系统的实际减振效果。 展开更多
关键词 结构响应主动控制 消振电力作动器 回差阵特征值法 x-lmS算法
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基于Adam算法的LMS优化
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作者 刘欢 徐德勃 +2 位作者 张涵涛 王皓月 靳洪旭 《电子制作》 2024年第12期114-116,113,共4页
虽然传统的LMS算法简单有效,但它的收敛速度较慢,容易受到初始权值选择和步长设置的影响。为了解决这个问题,我们引入了Adam算法的自适应学习率特性到LMS算法中。Adam算法通过一阶矩估计(mean)和二阶矩估计(variance)来估计梯度的均值... 虽然传统的LMS算法简单有效,但它的收敛速度较慢,容易受到初始权值选择和步长设置的影响。为了解决这个问题,我们引入了Adam算法的自适应学习率特性到LMS算法中。Adam算法通过一阶矩估计(mean)和二阶矩估计(variance)来估计梯度的均值和方差,并根据这些估计值来调整学习率。这样可以对梯度下降的方向和速度进行更精细地控制。通过Adam算法对LMS优化,LMS算法在更新权重时能够更加高效地利用梯度信息,从而提高训练速度和收敛性能。此外,优化后的算法还具有一些超参数,如beta1、beta2和eps等,需要根据具体的应用场景和数据特点进行调节,以获得最佳的优化效果。仿真结果表明优化方案比传统LMS算法在收敛过程中的震荡要更小。 展开更多
关键词 Adam算法 lmS算法 自适应滤波 梯度下降
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Time-sequential color code division multiplexing holographic display with metasurface 被引量:8
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作者 Xin Li Qinmiao Chen +4 位作者 Xue Zhang Ruizhe Zhao Shumin Xiao Yongtian Wang Lingling Huang 《Opto-Electronic Advances》 SCIE EI CAS CSCD 2023年第8期8-16,共9页
Color metasurface holograms are powerful and versatile platforms for modulating the amplitude,phase,polarization,and other properties of light at multiple operating wavelengths.However,the current color metasurface ho... Color metasurface holograms are powerful and versatile platforms for modulating the amplitude,phase,polarization,and other properties of light at multiple operating wavelengths.However,the current color metasurface holography can only realize static manipulation.In this study,we propose and demonstrate a multiplexing metasurface technique combined with multiwavelength code-division multiplexing(CDM)to realize dynamic manipulation.Multicolor code references are utilized to record information within a single metasurface and increase the information capacity and security for anticracks.A total of 48 monochrome images consisting of pure color characters and multilevel color video frames were reconstructed in dual polarization channels of the birefringent metasurface to exhibit high information density,and a video was displayed via sequential illumination of the corresponding code patterns to verify the ability of dynamic manipulation.Our approach demonstrates significant application potential in optical data storage,optical encryption,multiwavelengthversatile diffractive optical elements,and stimulated emission depletion microscopy. 展开更多
关键词 metasurface color holography dynamic display code division multiplexing
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Performance of phase-matching quantum key distribution based on wavelength division multiplexing technology 被引量:1
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作者 马海强 韩雁鑫 +1 位作者 窦天琦 李鹏云 《Chinese Physics B》 SCIE EI CAS CSCD 2023年第2期103-107,共5页
Quantum key distribution(QKD) generates information-theoretical secure keys between two parties based on the physical laws of quantum mechanics. The phase-matching(PM) QKD protocol allows the key rate to break the qua... Quantum key distribution(QKD) generates information-theoretical secure keys between two parties based on the physical laws of quantum mechanics. The phase-matching(PM) QKD protocol allows the key rate to break the quantum channel secret key capacity limit without quantum repeaters, and the security of the protocol is demonstrated by using equivalent entanglement. In this paper, the wavelength division multiplexing(WDM) technique is applied to the PM-QKD protocol considering the effect of crosstalk noise on the secret key rate. The performance of PM-QKD protocol based on WDM with the influence of adjacent classical channels and Raman scattering is analyzed by numerical simulations to maximize the total secret key rate of the QKD, providing a reference for future implementations of QKD based on WDM techniques. 展开更多
关键词 quantum key distribution wavelength division multiplexing secret key rate
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水稻类病变突变体lms1的表型鉴定与抗病分子机制分析
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作者 余瑶 王紫瑶 +5 位作者 周思睿 刘鹏程 叶亚峰 马伯军 刘斌美 陈析丰 《作物学报》 CAS CSCD 北大核心 2024年第4期857-870,共14页
类病变突变体是研究植物细胞死亡和抗病分子机制的重要遗传材料。通过辐射诱变粳稻品种武运粳7号,获得一个少见的抗病性下降的类病变突变体lms1(lesion mimic and disease susceptible mutant 1)。与野生型相比,该突变体叶片自发出现红... 类病变突变体是研究植物细胞死亡和抗病分子机制的重要遗传材料。通过辐射诱变粳稻品种武运粳7号,获得一个少见的抗病性下降的类病变突变体lms1(lesion mimic and disease susceptible mutant 1)。与野生型相比,该突变体叶片自发出现红褐色斑点,其株高、穗长、每穗粒数以及单株产量降低,但千粒重增加;对水稻白叶枯病的抗性显著下降,组织染色表明突变体的叶片中存在明显的细胞死亡以及活性氧的过量积累。遗传分析表明,lms1突变体的表型受单隐性核基因控制,利用图位克隆技术将lms1基因精细定位于水稻9号染色体Indel7和Indel8两个分子标记间,物理距离为62 kb。定位区间内候选基因的PCR扩增测序结果表明,其中一个编码泛素羧基末端水解酶的OsLMP1(Lesion Mimic Phenotype 1)基因第1个外显子中插入了一段长度为654 bp的序列,导致其蛋白翻译提前终止。利用蛋白组学技术分析了lms1突变体与野生型对照的蛋白积累水平,共鉴定到19个差异蛋白(7个上调、12个下调),主要参与氧化还原、叶绿素合成、光合作用等代谢途径。上述结果为进一步研究OsLMP1基因的功能及其调控细胞程序性死亡与抗病性的分子机制提供借鉴。 展开更多
关键词 水稻 类病变 lms1 基因定位 蛋白组学分析
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一种LM-BP加速搜索的周跳探测与修复方法
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作者 梁凌峰 李克昭 +2 位作者 张捍卫 雷伟伟 岳哲 《导航定位学报》 CSCD 北大核心 2024年第1期35-42,共8页
针对传统三频周跳探测与修复方法中的不敏感、漏检以及效率较低等问题,提出一种基于莱文伯格-马夸特(LM)-反向传播(BP)神经网络加速搜索法的伪距相位组合与电离层残差组合联合周跳探测与修复方法:利用2个伪距相位组合以减少不敏感周跳数... 针对传统三频周跳探测与修复方法中的不敏感、漏检以及效率较低等问题,提出一种基于莱文伯格-马夸特(LM)-反向传播(BP)神经网络加速搜索法的伪距相位组合与电离层残差组合联合周跳探测与修复方法:利用2个伪距相位组合以减少不敏感周跳数量,利用1个电离层残差组合以提高小周跳探测敏感度;在构成3个线性无关的组合观测值后,使用LM-BP加速搜索算法进行周跳探测与修复。实验结果表明,相对常规的伪距相位组合与电离层残差组合联合方法,该方法能够提高周跳探测与修复性能,可探测小至1个的周跳,探测与修复整体时效有较大提升。 展开更多
关键词 北斗卫星导航系统(BDS) 周跳探测与修复 莱文伯格-马夸特(lm)-反向传播(BP)算法 神经网络 伪距载波相位组合 电离层残差组合
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基于LM-BP神经网络的办公建筑逐时空调能耗预测
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作者 王曦 甘灵丽 +1 位作者 王亮 欧雪梅 《建筑节能(中英文)》 CAS 2024年第1期58-64,共7页
利用LM算法对BP神经网络进行改进,以提高模型收敛速度,减少迭代次数,并分别对夏季、冬季空调能耗模拟数据进行样本训练和测试,构建了LM-BP神经网络的办公建筑逐时空调能耗预测模型。结果表明夏季模型的预测值和模拟值之间的MAPE误差平均... 利用LM算法对BP神经网络进行改进,以提高模型收敛速度,减少迭代次数,并分别对夏季、冬季空调能耗模拟数据进行样本训练和测试,构建了LM-BP神经网络的办公建筑逐时空调能耗预测模型。结果表明夏季模型的预测值和模拟值之间的MAPE误差平均为5.74%,冬季模型的MAPE误差平均为5%,其误差均在10%以内,说明LM-BP神经网络在建筑空调能耗预测方面的可行性。并以成都地区某办公建筑实际空调能耗数据为基础对该模型进行了验证,其预测值与实际值平均相对误差为6.6%,说明建立的能耗预测模型能够满足实际工程的需要,准确的用电预测数据可为办公建筑用电侧进行实际电力市场交易提供科学的决策依据。 展开更多
关键词 空调能耗 lm算法 神经网络 办公建筑
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单核细胞增生李斯特菌LIPI-4 Lm4b_02327的基因克隆、生物信息学分析及原核表达
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作者 刘彩霞 马勋 +7 位作者 吕双飞 王静 寇丽君 史唯地 孔翠莲 钱瑞宣 高盛杰 任慧杰 《石河子大学学报(自然科学版)》 CAS 北大核心 2024年第3期313-320,共8页
目的 试验旨在获得单核细胞增生李斯特菌新疆冷冻鸡肉分离株LM928中LIPI-4 Lm4b_02327基因的重组蛋白。方法 根据Gen Bank中LM Clip80459菌株(登录号CAS06084.1)Lm4b_02327序列设计特异性引物,利用PCR对Lm4b_02327基因进行扩增,纯化目... 目的 试验旨在获得单核细胞增生李斯特菌新疆冷冻鸡肉分离株LM928中LIPI-4 Lm4b_02327基因的重组蛋白。方法 根据Gen Bank中LM Clip80459菌株(登录号CAS06084.1)Lm4b_02327序列设计特异性引物,利用PCR对Lm4b_02327基因进行扩增,纯化目的片段后克隆至pMD19-T载体,双酶切筛选阳性克隆进行测序。测序后利用软件预测Lm4b_02327序列编码蛋白质的理化性质、二级结构和三级结构,对该基因片段的核苷酸序列及编码的氨基酸序列进行同源性对比。同时构建pET32a-Lm4b_02327重组质粒,将其转化至大肠杆菌BL21(DE3)感受态细胞中,诱导表达,经SDS-PAGE检测、纯化蛋白后用Western Blot鉴定。结果 LM928菌株的Lm4b_02327基因全长为315 bp,共编码105个氨基酸,该蛋白为偏酸性、无信号肽、亲水性、无跨膜结构、定位于细胞质的不稳定蛋白,该蛋白质预测为PTSLacEⅡA组分。LM928菌株Lm4b_02327基因的核苷酸和氨基酸序列与CFSAN023463、52854、02-6680、02-6679、ICDC-LM188、LM3、N2306、GTA-L356和Clip80459菌株的同源性均为100.0%,与52860、FSL-J1-158和FSL J1-208菌株的核苷酸同源性分别为99.7%、97.8%和97.8%,与52860、FSL-J1-158和FSL J1-208菌株的氨基酸同源性分别为99.0%、94.3%和94.3%。系统进化树显示,LM928菌株的Lm4b_02327基因与4b血清型菌株聚为同一分支。经诱导后,pET32a-Lm4b_02327重组质粒在大肠杆菌BL21中大量表达,经SDS-PAGE和Western Blot鉴定表明该重组蛋白大小约为30 kDa,与预期大小一致。结论 本研究成功克隆Lm4b_02327基因,并获得该蛋白的大量表达,为深入研究蛋白功能奠定基础。 展开更多
关键词 单核细胞增多李斯特菌 lm4b_02327基因 生物信息学分析 原核表达
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Production evolution patterns and development stage division of waterflooding oilfields
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作者 JI Bingyu XU Ting +2 位作者 GAO Xingjun YU Hongmin LIU He 《Petroleum Exploration and Development》 SCIE 2023年第2期433-441,共9页
The continuous growth of recoverable reserves in a waterflooding oilfield has a significant impact on the patterns of production evolution. A new production evolution model is established by improving the Weng Cycle m... The continuous growth of recoverable reserves in a waterflooding oilfield has a significant impact on the patterns of production evolution. A new production evolution model is established by improving the Weng Cycle model. With the new model, the statistical correspondence between the production decline stage and the reserve-production imbalance is clarified,and the correlation of water cut with the recovery percent of recoverable reserves is discussed, providing quantitative basis of reservoir engineering for dividing development stages of oilfield and defining mature oilfields. According to the statistics of oilfields in eastern China, the time point corresponding to the reserve-production balance coefficient dropping to less than 1dramatically is well correlated the beginning point of production decline, thus the time when the reserve-production balance coefficient drops dramatically can be taken as the initiation point of production decline stage. The research results show that the water cut and the recovery percent of recoverable reserves have a good statistical match in the high water cut stage, and it is more rational to take both the start point of production decline stage and the water cut of 90%(or the recovery percent of recoverable reserves of 80%) as the critical criteria for defining a mature oilfield. Five production evolution patterns can be summarized as follows: growth–peak plateau–stepped decline, growth–stepped stabilizing–stepped decline, growth–stepped stabilizing–rapid decline, growth–peak plateau–rapid decline, and growth–continuous decline. 展开更多
关键词 waterflooding oilfield production evolution development stage division recoverable reserves mature oilfield
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Improved PBFT Consensus Algorithm Based on Node Role Division
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作者 Xiyu Ren Xiangrong Tong Wei Zhang 《Journal of Computer and Communications》 2023年第2期20-38,共19页
The PBFT (Practical Byzantine Fault Tolerance, PBFT) consensus algorithm, which addressed the issue of malicious nodes sending error messages to disrupt the system operation in distributed systems, was challenging to ... The PBFT (Practical Byzantine Fault Tolerance, PBFT) consensus algorithm, which addressed the issue of malicious nodes sending error messages to disrupt the system operation in distributed systems, was challenging to support massive network nodes, the common participation over all nodes in the consensus mechanism would lead to increased communication complexity, and the arbitrary selection of master nodes would also lead to inefficient consensus. This paper offered a PBFT consensus method (Role Division-based Practical Byzantine Fault Tolerance, RD-PBFT) to address the above problems based on node role division. First, the nodes in the system voted with each other to divide the high reputation group and low reputation group, and determined the starting reputation value of the nodes. Then, the mobile node in the group was divided into roles according to the high reputation value, and a total of three roles were divided into consensus node, backup node, and supervisory node to reduce the number of nodes involved in the consensus process and reduced the complexity of communication. In addition, an adaptive method was used to select the master nodes in the consensus process, and an integer value was introduced to ensure the unpredictability and equality of the master node selection. Experimentally, it was verified that the algorithm has lower communication complexity and better decentralization characteristics compared with the PBFT consensus algorithm, which improved the efficiency of consensus. 展开更多
关键词 Blockchain Consensus Algorithm Practical Byzantine Fault Tolerance Node Role division
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The Epigenetic“Dance”of Cell Divisions
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作者 YAN Fusheng 《Bulletin of the Chinese Academy of Sciences》 2023年第3期164-165,共2页
The tango of life begins with the very first cell division.New research reveals that to dance their way through development,dividing cells must pass along not just DNA but molecular“memories”that guide their destini... The tango of life begins with the very first cell division.New research reveals that to dance their way through development,dividing cells must pass along not just DNA but molecular“memories”that guide their destinies.When this handoff gets fumbled,the dance falls apart. 展开更多
关键词 dividing DANCE division.
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基于LM方法的麻花钻刃带宽度测量研究
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作者 周正 台立钢 +1 位作者 陈志远 张禹 《计量学报》 CSCD 北大核心 2024年第4期480-488,共9页
提出一种基于二值化的麻花钻刃带宽度检测方法。首先对目标边缘进行锐化,然后用巴特沃斯高通滤波提取边缘信息;其次通过改进的大津二值化算法对疑似边缘点进行阈值分割,获取边缘点坐标;再次使用列文伯格-马夸尔特(LM)方法对边缘附近的... 提出一种基于二值化的麻花钻刃带宽度检测方法。首先对目标边缘进行锐化,然后用巴特沃斯高通滤波提取边缘信息;其次通过改进的大津二值化算法对疑似边缘点进行阈值分割,获取边缘点坐标;再次使用列文伯格-马夸尔特(LM)方法对边缘附近的点进行拟合,得到刃带宽度曲线并求其拐点,求取麻花钻刃带宽度的数据。最后进行对比实验,用LM方法对未处理的M35直径2.5 cm的刃带图像进行处理得到刃带宽度1.467 mm,测量误差0.467 mm。改进后的测量结果为0.853 mm,测量误差为0.147 mm。 展开更多
关键词 几何量计量 麻花钻刃带宽度 列文伯格-马夸尔特方法 二值化算法 视觉测量
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