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Low-Cost Federated Broad Learning for Privacy-Preserved Knowledge Sharing in the RIS-Aided Internet of Vehicles 被引量:1
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作者 Xiaoming Yuan Jiahui Chen +4 位作者 Ning Zhang Qiang(John)Ye Changle Li Chunsheng Zhu Xuemin Sherman Shen 《Engineering》 SCIE EI CAS CSCD 2024年第2期178-189,共12页
High-efficiency and low-cost knowledge sharing can improve the decision-making ability of autonomous vehicles by mining knowledge from the Internet of Vehicles(IoVs).However,it is challenging to ensure high efficiency... High-efficiency and low-cost knowledge sharing can improve the decision-making ability of autonomous vehicles by mining knowledge from the Internet of Vehicles(IoVs).However,it is challenging to ensure high efficiency of local data learning models while preventing privacy leakage in a high mobility environment.In order to protect data privacy and improve data learning efficiency in knowledge sharing,we propose an asynchronous federated broad learning(FBL)framework that integrates broad learning(BL)into federated learning(FL).In FBL,we design a broad fully connected model(BFCM)as a local model for training client data.To enhance the wireless channel quality for knowledge sharing and reduce the communication and computation cost of participating clients,we construct a joint resource allocation and reconfigurable intelligent surface(RIS)configuration optimization framework for FBL.The problem is decoupled into two convex subproblems.Aiming to improve the resource scheduling efficiency in FBL,a double Davidon–Fletcher–Powell(DDFP)algorithm is presented to solve the time slot allocation and RIS configuration problem.Based on the results of resource scheduling,we design a reward-allocation algorithm based on federated incentive learning(FIL)in FBL to compensate clients for their costs.The simulation results show that the proposed FBL framework achieves better performance than the comparison models in terms of efficiency,accuracy,and cost for knowledge sharing in the IoV. 展开更多
关键词 Knowledge sharing Internet of Vehicles Federated learning broad learning Reconfigurable intelligent surfaces Resource allocation
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BLS-identification:A device fingerprint classification mechanism based on broad learning for Internet of Things
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作者 Yu Zhang Bei Gong Qian Wang 《Digital Communications and Networks》 SCIE CSCD 2024年第3期728-739,共12页
The popularity of the Internet of Things(IoT)has enabled a large number of vulnerable devices to connect to the Internet,bringing huge security risks.As a network-level security authentication method,device fingerprin... The popularity of the Internet of Things(IoT)has enabled a large number of vulnerable devices to connect to the Internet,bringing huge security risks.As a network-level security authentication method,device fingerprint based on machine learning has attracted considerable attention because it can detect vulnerable devices in complex and heterogeneous access phases.However,flexible and diversified IoT devices with limited resources increase dif-ficulty of the device fingerprint authentication method executed in IoT,because it needs to retrain the model network to deal with incremental features or types.To address this problem,a device fingerprinting mechanism based on a Broad Learning System(BLS)is proposed in this paper.The mechanism firstly characterizes IoT devices by traffic analysis based on the identifiable differences of the traffic data of IoT devices,and extracts feature parameters of the traffic packets.A hierarchical hybrid sampling method is designed at the preprocessing phase to improve the imbalanced data distribution and reconstruct the fingerprint dataset.The complexity of the dataset is reduced using Principal Component Analysis(PCA)and the device type is identified by training weights using BLS.The experimental results show that the proposed method can achieve state-of-the-art accuracy and spend less training time than other existing methods. 展开更多
关键词 Device fingerprint Traffic analysis Class imbalance broad learning system Access authentication
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Boosting Adaptive Weighted Broad Learning System for Multi-Label Learning
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作者 Yuanxin Lin Zhiwen Yu +2 位作者 Kaixiang Yang Ziwei Fan C.L.Philip Chen 《IEEE/CAA Journal of Automatica Sinica》 SCIE EI CSCD 2024年第11期2204-2219,共16页
Multi-label classification is a challenging problem that has attracted significant attention from researchers, particularly in the domain of image and text attribute annotation. However, multi-label datasets are prone... Multi-label classification is a challenging problem that has attracted significant attention from researchers, particularly in the domain of image and text attribute annotation. However, multi-label datasets are prone to serious intra-class and inter-class imbalance problems, which can significantly degrade the classification performance. To address the above issues, we propose the multi-label weighted broad learning system(MLW-BLS) from the perspective of label imbalance weighting and label correlation mining. Further, we propose the multi-label adaptive weighted broad learning system(MLAW-BLS) to adaptively adjust the specific weights and values of labels of MLW-BLS and construct an efficient imbalanced classifier set. Extensive experiments are conducted on various datasets to evaluate the effectiveness of the proposed model, and the results demonstrate its superiority over other advanced approaches. 展开更多
关键词 broad learning system label correlation mining label imbalance weighting multi-label imbalance
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Spontaneous Paravesical and Broad Ligament Hematoma after Vaginal Delivery Had Uterine Artery Embolization after Evacuating the Hematoma
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作者 Aayat Jaaffar Naseeb Abrar Majdi Al Nasheet 《Open Journal of Obstetrics and Gynecology》 2024年第3期480-486,共7页
Broad ligament hematoma is typically seen during cesarean section due to rupture of branches of uterine and vaginal vessels and it’s rare to be seen post-normal vaginal delivery. Addressing puerperal hematomas postpa... Broad ligament hematoma is typically seen during cesarean section due to rupture of branches of uterine and vaginal vessels and it’s rare to be seen post-normal vaginal delivery. Addressing puerperal hematomas postpartum presents considerable challenges for obstetric care providers. While hematomas such as those affecting the vulva, vulvovaginal region, or paravaginal area are frequently encountered, retroperitoneal hematomas are rare and notably pose a greater risk to the life of the patient. The medical literature contains scant case reports on retroperitoneal hematomas, with no consensus on a definitive treatment approach. Pelvic arterial embolization has emerged as both a sensible and increasingly preferred method for treating these hematomas recently, but its application is contingent upon the patient maintaining hemodynamic stability and the availability of a specialized interventional embolization unit. In our case, we are presenting a very rare case of a 31-year-old primigravida female with a history of in vitro fertilization pregnancy. She delivered a normal vaginal delivery at 31 weeks gestation. Unfortunately, she experienced multiple complications intrapartum, including preeclampsia and placental abruption. These complications increased her risk of developing a broad ligament hematoma. 展开更多
关键词 broad Ligament Paravesical Hematoma Spontaneous Hematoma Uterine Artery Embolization Retroperitoneal Hematoma Vaginal Delivery
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Nutritional Value and Application of Broad Bean Nutrition Flour as a Combination of Staple Food 被引量:4
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作者 吴春芳 林晶晶 +2 位作者 卞晓春 陈惠 夏礼如 《Agricultural Science & Technology》 CAS 2015年第6期1280-1285,共6页
This paper introduced the definition and importance of combination of sta-ple food. With broad bean nutrition flour as a sample, the preparation of the combi-nation of staple food was also described. In addition, the ... This paper introduced the definition and importance of combination of sta-ple food. With broad bean nutrition flour as a sample, the preparation of the combi-nation of staple food was also described. In addition, the main nutritional value of broad bean nutrition flour was introduced. Compared with those of other single flours, the nutritional value of broad bean nutrition flour was improved. Moreover, the nutrients in the broad bean nutrition flour would not be destroyed during the processing and preparation of staple food, and the processed steamed bread and raw noodle are more characteristic. The application value and prospects of broad bean nutrition flour, as a combination of staple food, were further discussed. 展开更多
关键词 broad bean nutrition flour Combination of staple food APPLICATION
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FTIR Spectroscopic Study of Broad Bean Diseased Leaves 被引量:2
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作者 李志永 刘刚 +5 位作者 李伦 欧全宏 赵兴祥 张黎 周湘萍 汪禄祥 《Agricultural Science & Technology》 CAS 2012年第11期2363-2366,2408,共5页
[Objective] The aim was to indentify diseased leaves of broad bean by vibra- tional spectroscopy. [Method] In this paper, broad bean rust, fusarium rhizome rot, broad bean zonate spot, yellow leaf curl virus and norma... [Objective] The aim was to indentify diseased leaves of broad bean by vibra- tional spectroscopy. [Method] In this paper, broad bean rust, fusarium rhizome rot, broad bean zonate spot, yellow leaf curl virus and normal leaves were studied using Fourier transform infrared spectroscopy combined with chemometrics. [Result] The spectra of the samples were similar, only with minor differences in absorption inten- sity of several peaks. Second derivative analyses show that the significant difference of all samples was in the range of 1 200-700 cm2. The data in the range of 1 200- 700 cm' were selected to evaluate correlation coefficients, hierarchical cluster analy- sis (HCA) and principal component analysis (PCA). Results showed that the correla- tion coefficients are larger than 0.928 not only between the healthy leaves, but also between the same diseased leaves. The values between healthy and diseased leaves, and among diseased leaves, are all declined. HCA and PCA yielded about 73.3% and 82.2% accuracy, respectively. [Conclusion] This study demonstrated that FTIR techniques might be used to detect crop diseases. 展开更多
关键词 FTIR spectroscopy broad bean diseases Principal component analysis Cluster analysis
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Effects of Facilities Condition on Occurrence of Freeze Injury and Fresh Pod Yield of Broad Bean 被引量:2
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作者 吴春芳 卞晓春 +1 位作者 曹云英 夏礼如 《Agricultural Science & Technology》 CAS 2015年第5期890-897,共8页
Using Tongxian No.2 as material, the effects of different film-covering time, different sowing time and different planting density on the occurrence of freeze injury and yield of fresh broad beans were investigated. T... Using Tongxian No.2 as material, the effects of different film-covering time, different sowing time and different planting density on the occurrence of freeze injury and yield of fresh broad beans were investigated. The randomized block design was adopted. The results showed that with the delayed film covering, the incidence of mild freeze injury and number of headless seedlings were increased correspondingly, but the yield was increased; with the delayed sowing, the branch number per plant, effective branch number per plant, incidence of mild freeze injury and number of headless seedlings were all reduced, and the broad beans, sowed on September 30 th, obtained the highest yield; planting density showed on effect on the occurrence of freeze injury, and the yield was increased with the increase of planting density. Under the same film-covering time, the incidence of freeze injury was reduced with the delayed sowing time and it showed no changes when planting density was changed, but the yield was increased with the increase of planting density and it was highest when broad bean seeds were sowed on September 30th;under the same sowing time, the incidence of freeze injury was increased with the delayed film-covering time and it showed no changes when planting density was changed, and the yield was increased with the delayed film-covering time and increased planting density; under the same planting density, the incidence of freeze injury was increased with the delayed film-covering time but was reduced with the delayed sowing time, and the yield was increased with the delayed film-covering time and it was highest when the broad bean seeds were sowed on September30 th. Under same film-covering time and sowing time, the total branch number per plant and effective branch number per plant were reduced, but the yield was increased with the increase of planting density; under same film-covering time and planting density, the incidence of freeze injury was reduced with the delayed sowing time, and the yield was highest when broad bean seeds were sowed on September30th; under same sowing time and planting density, the incidence of freeze injury and the yield were all increased with the delayed film-covering time. 展开更多
关键词 Facility broad bean Film-covering time Sowing time Planting density Freeze injury Fresh pod yield
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Detection of Broad Bean Diseases by Fourier Transform Infrared Spectroscopy Combined with Curve Fitting 被引量:1
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作者 汪小华 刘刚 +4 位作者 欧全宏 周湘萍 郝建明 刘剑虹 汪禄祥 《Agricultural Science & Technology》 CAS 2015年第6期1310-1313,共4页
Fourier transform infrared (FTIR) spectroscopy was used to study diseased leaves in broad bean. Results showed that the infrared spectra of different broad bean diseased leaves were similar, which were mainly made u... Fourier transform infrared (FTIR) spectroscopy was used to study diseased leaves in broad bean. Results showed that the infrared spectra of different broad bean diseased leaves were similar, which were mainly made up of the vibrational absorption bands of protein,lipid and polysaccharide.There were minor differences in-cluding the spectral peak position, peak shape and the absorption intensity in the range of 1 800-1 300 cm-1. There were obvious differences among their second derivative spectra in the range of 1 800-1 300 cm-1. After the procedure of the Fourier self-deconvolution and curve fitting of health bean leaves and broad bean diseased leaves in the range of 1 700-1 500 cm-1, three sub-peaks were obtained at 1 550 cm-1 (protein amide Ⅱ band), 1 605 cm-1 (lignin) and 1 650 cm-1 (protein amide I band).The ratios of relative areas of the bands of amide Ⅱ, lignin, and amide I were 38.86%, 28.68% and 32.47% in the spectra of healthy leaves, respec-tively. It was distinguished from the diseased leaves (chocolate spot leaf: 15.42%, 42.98% and 41.61%, ring spot leaf:32.39%, 35.63% and 31.98%, rust leaf: 13.97%, 46.40% and 39.65%, yel owing leaf curl disease leaf: 24.01%,36.55% and 39.44%). For sub-peak area ratios (A1 563/A1 605, A1 650/A1 605 and A1 563/A1 654), those of four kinds of diseased leaves were smal er than that of healthy leaves, and there were also differences among four kinds of diseased leaves. The results proved that FTIR combining with curve fitting might be a potential y useful tool for detecting different kinds of broad bean diseases. 展开更多
关键词 Fourier transform infrared (FTIR) spectroscopy broad bean diseases Second derivative spectra Curve fitting
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微冻对蚕豆籽粒保鲜效果及成熟衰老的影响
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作者 李蝶 李海燕 +3 位作者 钟士宏 付院生 李梅青 张海伟 《食品科学》 EI CAS 北大核心 2025年第1期149-157,共9页
探究微冻技术对新鲜蚕豆籽粒的保鲜效果。通过测定蚕豆籽粒的冰点,确定3个微冻温度,以冷藏(4℃)为对照组,分析不同微冻温度(-2、-3、-4℃)贮藏对蚕豆籽粒感官品质、叶绿素含量、色差值等品质指标的影响,再通过多酚氧化酶(polyphenol oxi... 探究微冻技术对新鲜蚕豆籽粒的保鲜效果。通过测定蚕豆籽粒的冰点,确定3个微冻温度,以冷藏(4℃)为对照组,分析不同微冻温度(-2、-3、-4℃)贮藏对蚕豆籽粒感官品质、叶绿素含量、色差值等品质指标的影响,再通过多酚氧化酶(polyphenol oxidase,PPO)、过氧化物酶(peroxidase,POD)、苯丙氨酸解氨酶(phenylalamine ammonia lyase,PAL)活性、总酚含量、可溶性蛋白含量及细胞组织结构等研究微冻贮藏对蚕豆籽粒成熟衰老的影响。结果表明,4℃冷藏条件下蚕豆籽粒保鲜期为7 d,3个微冻温度贮藏均能显著提高样品的感官品质,其中-3℃使蚕豆籽粒保鲜期达35 d,能显著减缓叶绿素含量的降低和质量损失率、色差值的升高,能较好地维持蚕豆籽粒的硬度,采用主成分分析也得出-3℃为最佳微冻温度。-3℃微冻贮藏能减缓PPO、PAL活性升高,维持较高的POD活性,延缓蚕豆籽粒中淀粉和可溶性蛋白的生成、总酚的积累及变化速率,还能维持细胞组织结构、形态的相对稳定,减缓蚕豆籽粒的成熟衰老。 展开更多
关键词 蚕豆籽粒 微冻保鲜 贮藏期 品质变化 成熟衰老
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常绿阔叶林壳斗科植物的空间分布格局及其影响因素
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作者 柏爱琴 陈韬 +1 位作者 罗应华 李嘉亮 《东北林业大学学报》 CAS 北大核心 2025年第2期75-85,共11页
以广西壮族自治区的十万大山、花坪、岑王老山国家级自然保护区为研究区域,设置9个100 m×100 m固定样地,将每个样地划分为25个20 m×20 m的样方,再将样方划分为16个5 m×5 m的小样方;采用空间代替时间(即径级结构代替树龄... 以广西壮族自治区的十万大山、花坪、岑王老山国家级自然保护区为研究区域,设置9个100 m×100 m固定样地,将每个样地划分为25个20 m×20 m的样方,再将样方划分为16个5 m×5 m的小样方;采用空间代替时间(即径级结构代替树龄结构)的方法,用胸径(D_(BH))将壳斗科(Fagaceae)树种个体划分为小树(1.0 cm≤D_(BH)<5.0 cm)、中树(5.0 cm≤D_(BH)<20.0 cm)、大树(D_(BH)≥20.0 cm)3个径级阶段;选取样地中胸径D_(BH)≥1.0 cm的所有壳斗科个体为研究对象,进行每木检尺,记录树种名称,测定胸径、树高、冠幅、枝下高等测树因子以及每棵树的位置坐标;以空间聚集程度为评价指标,以海拔、经度、纬度、年降水量、春季降水、夏季降水、年均温、年均最高温、年均最低温、1月份均温、7月份均温为影响因素,采用克鲁斯卡尔-沃利斯检验法(Kruskal-Wallis test,K-W检验)、Ripley L函数结合完全随机模型(CSR)、线性回归分析方法、皮尔逊(Pearson)相关性分析法,分析壳斗科不同径级树种的空间分布格局及各因素对其分布的影响。结果表明:①壳斗科小树、中树、整个类群的分布格局主要是聚集分布,而大树主要表现为随机分布;随径级的增加,壳斗科树种的聚集程度由大到小依次为小树、中树、整体、大树。②小树、中树、整个类群在10 m空间尺度上的聚集程度(L_(10)),与年降水、年均温、年均最高温、年均最低温、1月份均温、7月份均温均呈显著正相关(P<0.05),且小树阶段的空间聚集程度更易受气温、降水的影响;大树的聚集程度(L_(10)),与年均温、年均最高温、年均最低温、1月份均温均呈显著正相关(P<0.05);壳斗科各径级树种的聚集程度,与纬度呈显著负相关(P<0.05),与海拔呈负相关。壳斗科树种的空间分布格局主要受扩散限制和气候因素的影响,并且不同径级树种与同一气候因子间的相关性趋势一致,但程度存在差异。 展开更多
关键词 常绿阔叶林 壳斗科植物 空间分布格局 扩散限制
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3种天然阔叶混交林林木物种和大小分化多样性与地形的耦合关系
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作者 郜昌建 王海龙 +1 位作者 徐森 张小伟 《东北林业大学学报》 CAS 北大核心 2025年第2期16-24,共9页
依据2021年浙江省森林资源连续清查数据,选取969个幼龄林和中林龄天然阔叶混交林样地,并依据样地植被型将样地划分为常绿阔叶林、落叶阔叶林和常绿落叶阔叶3种植被类型,采用方差分析及Pearson分析地形与林木物种和大小分化多样性的关系... 依据2021年浙江省森林资源连续清查数据,选取969个幼龄林和中林龄天然阔叶混交林样地,并依据样地植被型将样地划分为常绿阔叶林、落叶阔叶林和常绿落叶阔叶3种植被类型,采用方差分析及Pearson分析地形与林木物种和大小分化多样性的关系。结果表明:1)3种植被类型间物种多样性指标间均呈显著差异(P<0.05),落叶阔叶林胸径变异系数和胸径均匀度显著高于常绿阔叶林(P<0.05),而常绿阔叶林胸径香农维纳指数显著高于落叶阔叶林和常绿落叶阔叶林(P<0.05);2)随海拔或坡度的升高,3种植被类型丰富度、香农维纳指数和辛普森多样性指数均显著升高(P<0.05),但落叶阔叶林和常绿落叶阔叶林Pielou均匀度指数无明显差异,坡向对林木物种多样性无明显影响;3)随海拔升高,3种植被类型胸径变异系数和胸径均匀度整体上均呈降低趋势,而胸径香农维纳指数则相反;由阳坡到阴坡,常绿阔叶林和常绿落叶阔叶林胸径均匀度指数整体上均呈升高趋势;随坡度增加,落叶阔叶林胸径变异系数和3种植被类型胸径均匀度均降低,而落叶阔叶林胸径香农维纳指数则相反。海拔和坡度对3种植被类型树种数量、胸径均匀度有明显影响,但对落叶阔叶林和常绿落叶阔叶林树种均匀度、常绿阔叶林胸径变异系数均无明显影响,而坡向主要影响常绿阔叶林和常绿落叶阔叶林胸径均匀度。 展开更多
关键词 天然阔叶混交林 地形 物种多样性 大小分化多样性
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加勒比松针阔混交改造初期对林下植被多样性及土壤理化性质的影响
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作者 张挺 杨德任 +4 位作者 毛纯 朱原立 庞伟灿 杨梅 邓善宝 《北华大学学报(自然科学版)》 CAS 2025年第1期84-92,共9页
从林下植被多样性、土壤理化性质探讨合理的加勒比松人工纯林改良模式,为提高加勒比松纯林生态稳定性及混交林树种选择提供科学依据。以加勒比松纯林(PP)、加勒比松×灰木莲(MF1)、加勒比松×红锥(MF2)、加勒比松×灰木莲&#... 从林下植被多样性、土壤理化性质探讨合理的加勒比松人工纯林改良模式,为提高加勒比松纯林生态稳定性及混交林树种选择提供科学依据。以加勒比松纯林(PP)、加勒比松×灰木莲(MF1)、加勒比松×红锥(MF2)、加勒比松×灰木莲×红锥(MF3)混交林为研究对象,分析4种林分林下植被多样性和土壤理化性质差异。结果显示:1)3种混交林草本层多样性指数均显著高于PP,其中MF1最大,MF3次之;3种混交林灌木层物种丰富度指数均显著提高,Simpson指数、Shannon-Wiener指数仅MF3显著高于PP,Pielou指数差异不显著。2)不同林分间土壤容重差异不显著,3种混交林土壤含水率和土壤孔隙度均高于PP,均为MF3最优。3)除硝态氮外,MF2和MF3的0~20 cm、20~40 cm土层土壤有机碳、全氮、铵态氮、全钾、速效钾和速效磷含量均显著高于PP。4)相关性分析表明,灌木层多样性指数与土壤理化性质的相关性强于草本层,而草本层与土壤速效磷含量的相关性较强;冗余分析表明,土壤有机碳、速效磷是影响林下植被多样性的主要因子。与PP相比,MF1、MF2、MF3均能够显著提高灌木层物种丰富度和草本层植被多样性指数。同时,混交林还改善了土壤水分和孔隙状况,提高了土壤有机碳和氮、磷、钾的全量和有效养分含量,且套种多树种混交改良效果明显优于套种单一树种的混交林。 展开更多
关键词 加勒比松 针阔混交林 林下植被多样性 土壤理化性质
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Effects of Pb on Growth and Development of Broad Bean Roots
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作者 张燕 《Agricultural Science & Technology》 CAS 2013年第4期595-597,共3页
[Objective] This study aimed to investigate the influence of Pb2+ on the growth and development of broad bean roots. [Method] The effects of Pb2+ solution of different concentrations on root length, color, bending a... [Objective] This study aimed to investigate the influence of Pb2+ on the growth and development of broad bean roots. [Method] The effects of Pb2+ solution of different concentrations on root length, color, bending and mitotic index frequency of root tip cells of broad bean were measured and observed. [Result] Pb2+ at concentration lower than 20 mg/L promoted the growth and development of roots, increased the cell mitotic indexes, but had little influence on root color and bending. When the Pb2+ concentration was higher than 20 mg/L, the root growth was inhibited; the root color gradually turned deeper; the roots bended, but the cell mitotic index was decreased. [Conclusion] Pb2+ promoted the growth of broad bean at low concentration but inhibited the growth at high concentration, and the influence was related to Pb2+ concentration and time. 展开更多
关键词 Pb2+ broad bean Root length BENDING COLOR MITOSIS
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基于预训练表示和宽度学习的虚假新闻早期检测
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作者 胡舜邦 王琳 刘伍颖 《郑州大学学报(理学版)》 CAS 北大核心 2025年第2期31-36,共6页
为了实现虚假新闻的早期检测,提出一种基于预训练表示和宽度学习的虚假新闻早期检测方法。首先,将新闻文本输入大规模预训练语言模型RoBERTa中,得到对应新闻文本的上下文语义表示。其次,将得到的新闻文本的上下文语义表示输入宽度学习... 为了实现虚假新闻的早期检测,提出一种基于预训练表示和宽度学习的虚假新闻早期检测方法。首先,将新闻文本输入大规模预训练语言模型RoBERTa中,得到对应新闻文本的上下文语义表示。其次,将得到的新闻文本的上下文语义表示输入宽度学习的特征节点和增强节点中,利用宽度学习的特征节点和增强节点进一步提取新闻文本的线性和非线性特征并构造分类器,从而预测新闻的真实性。最后,在3个真实数据集上进行了对比实验,结果表明,所提方法可以在4 h内检测出虚假新闻,准确率超过80%,优于基线方法。 展开更多
关键词 早期检测 虚假新闻 预训练表示 宽度学习 文本分类
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长期生态学研究中的经典实验途径——Lawcs和Gilbrt的Broad balk实验
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作者 周德本 《国土与自然资源研究》 1992年第S1期19-21,共3页
没有长期实验领域的资料而去讨论长期实验是困难的,最早的实验在Rothamsted进行,在那里,测定了植物的氮素来源和化肥及农家肥对小麦产量的影响,该实验始于1843年,与类似的芜%Barnfild实验一样,随后变得更复杂而最终终止了。Barnfield... 没有长期实验领域的资料而去讨论长期实验是困难的,最早的实验在Rothamsted进行,在那里,测定了植物的氮素来源和化肥及农家肥对小麦产量的影响,该实验始于1843年,与类似的芜%Barnfild实验一样,随后变得更复杂而最终终止了。Barnfield实验以其简单的形式,仍然存在着而基本上没有改变,就象那时能够想象一样,该实验对“长期实验”做出了贡献,简单的设计可能是其成功的关键。当随后R.A.Fi sher试图分析时,这导致他设计新的野外实验统计和随机因子设计(Fisher 1925,1935),并变成了后来田间分析的基础;因为Broadbalk没有反复的实验,现在也不能重复;已经产生了如此多的不同且可改变的变化,就象后来土壤分析所示的,这是在做到最初目的之后继续取样的。存在(Survival)已是实验最显著的成就之一,一起进行的有费歇尔(Fi的叮i*)的田间统计和对土壤、植物营养、/h麦产量、病害、昆虫、线虫、微生物和杂草的研究(例子见Bawden)。 展开更多
关键词 broad balk Gilbrt Lawcs 植物营养 因子设计 费歇尔 Gilbert 土壤分析 ECOLOGY 样地
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川渝地区豆瓣的常规理化和挥发性风味物质及细菌群落分析
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作者 屠大伟 马宏能 +2 位作者 李佳 康峻菡 刘文俊 《食品科学》 EI CAS 北大核心 2025年第3期187-195,共9页
以川渝地区豆瓣酱为研究对象,采用顶空固相微萃取-气相色谱-质谱、高通量测序等方法,分析豆瓣酱的理化特性、细菌群落结构和挥发性风味物质的组成及含量。结果显示,9种豆瓣酱的水分质量分数为54.33%~70.46%,食盐质量分数为12.49%~16.90%... 以川渝地区豆瓣酱为研究对象,采用顶空固相微萃取-气相色谱-质谱、高通量测序等方法,分析豆瓣酱的理化特性、细菌群落结构和挥发性风味物质的组成及含量。结果显示,9种豆瓣酱的水分质量分数为54.33%~70.46%,食盐质量分数为12.49%~16.90%,总酸质量分数为0.44%~1.46%,氨基酸态氮质量分数为0.17%~0.41%。由挥发性物质组成及气味活度值(odor activity value,OAV)分析结果可知,样品中OAV≥1的挥发性物质共有32种,其中,异戊醇、芳樟醇、苯乙醇、异戊醛、2-甲基丁醛、苯乙醛、苯乙酸乙酯、月桂酸甲酯、月桂酸乙酯、异戊酸、4-乙基苯酚和4-愈创木酚是川渝地区豆瓣的特征风味物质,能够赋予豆瓣花香、果香、麦芽香及酱香等气味特征。川渝地区豆瓣酱的优势细菌门为厚壁菌门、变形菌门和蓝藻门,优势细菌属为芽孢杆菌属、假单胞菌属、葡萄球菌属、海洋芽孢杆菌属、乳杆菌属和肠杆菌属。利用正交偏最小二乘判别分析建立稳定性较好的预测模型,结合变量投影重要性值>1的标准,筛选出29种特征挥发性化合物。通过Spearman分析发现,豆瓣酱中的风味特征物质与优势细菌属之间存在相关性,本实验可为川渝地区豆瓣的深入研究奠定基础,并对其产品的工艺优化提供参考依据。 展开更多
关键词 豆瓣酱 顶空固相微萃取-气相色谱-质谱联用 挥发性风味物质 高通量测序
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A Broad Learning-Driven Network Traffic Analysis System Based on Fog Computing Paradigm 被引量:3
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作者 Xiting Peng Kaoru Ota Mianxiong Dong 《China Communications》 SCIE CSCD 2020年第2期1-13,共13页
The development of communication technologies which support traffic-intensive applications presents new challenges in designing a real-time traffic analysis architecture and an accurate method that suitable for a wide... The development of communication technologies which support traffic-intensive applications presents new challenges in designing a real-time traffic analysis architecture and an accurate method that suitable for a wide variety of traffic types.Current traffic analysis methods are executed on the cloud,which needs to upload the traffic data.Fog computing is a more promising way to save bandwidth resources by offloading these tasks to the fog nodes.However,traffic analysis models based on traditional machine learning need to retrain all traffic data when updating the trained model,which are not suitable for fog computing due to the poor computing power.In this study,we design a novel fog computing based traffic analysis system using broad learning.For one thing,fog computing can provide a distributed architecture for saving the bandwidth resources.For another,we use the broad learning to incrementally train the traffic data,which is more suitable for fog computing because it can support incremental updates of models without retraining all data.We implement our system on the Raspberry Pi,and experimental results show that we have a 98%probability to accurately identify these traffic data.Moreover,our method has a faster training speed compared with Convolutional Neural Network(CNN). 展开更多
关键词 traffic analysis fog computing broad learning radio access networks
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Linear Piezoelectric Stepping Motor with Broad Operating Frequency 被引量:2
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作者 陈西府 王寅 +1 位作者 孙梦馨 黄卫清 《Transactions of Nanjing University of Aeronautics and Astronautics》 EI CSCD 2015年第2期137-142,共6页
The existing resonant linear piezoelectric motors must operate with high working voltage in resonant condition,resulting in their narrow operating frequency range and poor running stability.Here,with the large displac... The existing resonant linear piezoelectric motors must operate with high working voltage in resonant condition,resulting in their narrow operating frequency range and poor running stability.Here,with the large displacement output characteristics of piezoelectric stacks,the trajectory at the drive foot of stator is firstly produced with two space quadrature piezoelectric actuators excited by sawtooth wave and square wave.Secondly,the friction drive principle of motor is used to analyze the working mechanisms of the continuous stepping motion.Finally,the motor prototype is designed and experiments are carried out.The experimental result shows that the motor can stably operate within the scope of 350 Hz to 750 Hz.When the excitation voltage is 30 Vand pre-load is 3Nor10 N,the lateral amplitude of the drive foot is approximately 4μm and the stable average interval ranges from3.1μm to 3.2μm with the error rate of 5%—7.5%. 展开更多
关键词 linear motor piezoelectric stack stepping motor broad operating frequency
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Study on guided-mode resonance characteristic of multilayer dielectric grating with broadband and wide using-angle 被引量:2
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作者 汪剑鹏 晋云霞 +2 位作者 麻健勇 邵建达 范正修 《Chinese Physics B》 SCIE EI CAS CSCD 2010年第5期276-287,共12页
Guided-mode resonance in a diffraction band of multilayer dielectric gratings may lead to a catastrophic result in laser system, especially in the ultrashort pulse laser system, so the inhibition of guided-mode resona... Guided-mode resonance in a diffraction band of multilayer dielectric gratings may lead to a catastrophic result in laser system, especially in the ultrashort pulse laser system, so the inhibition of guided-mode resonance is very important. In this paper the characteristics of guided-mode resonance in multilayer dielectric grating are studied with the aim of better understanding the physical process of guided-mode resonance and designing a broadband multilayer dielectric grating with no guided-mode resonance. By employing waveguide theory, all guided-wave modes appearing in multilayer dielectric grating are found, and the incident conditions, separately, corresponding to each guided-wave mode are also obtained. The electric field enhancement in multilayer dielectric grating is shown obviously. Furthermore, from the detailed analyses on the guided-mode resonance conditions, it is found that the reduction of the grating period would effectively avoid the appearing of guided-mode resonance. And the expressions for calculating maximum periods, which ensure that no guided-mode resonance occurs in the requiring broad angle or wavelength range, are first reported. The above results calculated by waveguide theory and Fourier mode method are compared with each other, and they are coincident completely. Moreover, the method that relies on waveguide theory is more helpful for understanding the guided-mode resonance excited process and analyzing how each parameter affects the characteristic of guided-mode resonance. Therefore, the effects of multilayer dielectric grating parameters, such as period, fill factor, thickness of grating layer, et al., on the guided-mode resonance characteristic are discussed in detail based on waveguide theory, and some meaningful results are obtained. 展开更多
关键词 multilayer dielectric grating guided-mode resonance broad band
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Higher degree moment tensor inversion of Mani earthquake using far-field broadband recording 被引量:2
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作者 刘瑞丰 陈运泰 +3 位作者 成瑾 杨辉 韩炜 牟磊育 《Acta Seismologica Sinica(English Edition)》 CSCD 2000年第3期241-248,共8页
Breakthrough point source model, extended earthquake source model is used to calculate more seismic source parameters in this paper. We express seismic source using higher degree moment tensors, to reduce a Iarge numb... Breakthrough point source model, extended earthquake source model is used to calculate more seismic source parameters in this paper. We express seismic source using higher degree moment tensors, to reduce a Iarge number terms originally presenting in higher degree moment tensor representation, Haskell rupture model is used. We in verted the source parameters of Mani earthquake in Tibet using broad-band body wave of 32 stations of Global Seismograph Network (GSN), the results show that it is a strike-slip fault, rupture direction is 75°, rupture duration is 19 s, the fault plan is φ=77°, δ5=88°, A=0°, the auxiliare plane is φ=347°, δ=90°, k=178°, and the fault dimension is 47 km×28 km. These results will give new quantitative data for earth dynamics and have practical meaning for seismic source tomography research. 展开更多
关键词 Mani earthquake higher degree moment tensor seismic source parameters broad band DIGITIZATION
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