期刊文献+
共找到1,327篇文章
< 1 2 67 >
每页显示 20 50 100
基于STC15W204S的电子式速度继电器设计与实现
1
作者 林必忠 余华春 富兴波 《机电信息》 2026年第1期13-17,共5页
以STC15W204S单片机为核心控制器,设计并实现了一种电子式速度继电器。系统采用两个HAL3144霍尔传感器采集电机转盘上磁钢的过磁信号,通过单片机对两路存在相位差的方波信号进行捕获与处理,精确计算出电机的实时转速并判断其旋转方向。... 以STC15W204S单片机为核心控制器,设计并实现了一种电子式速度继电器。系统采用两个HAL3144霍尔传感器采集电机转盘上磁钢的过磁信号,通过单片机对两路存在相位差的方波信号进行捕获与处理,精确计算出电机的实时转速并判断其旋转方向。控制器电源直接由工业现场AC380V电源经降压、整流、稳压后提供,具备高抗干扰性和工业适用性。实际测试表明,该系统结构简单、成本低廉、运行稳定、测量准确,能够可靠地应用于工业电机转速监控、转向判别及超速/低速保护等场景。 展开更多
关键词 速度继电器 sTC15w204s 霍尔传感器 HAL3144 转速测量 转向判别 工业控制
在线阅读 下载PDF
Characteristics of Industrial Cluster Networks from the Perspective of Smart Specialization:A Case Study of Jiangsu Province,China 被引量:1
2
作者 SHEN Lizhen BI Xiaopu +3 位作者 CUI Zhe ZHANG Shanqi LIU Shenyu WANG Xia 《Chinese Geographical Science》 2025年第6期1376-1391,共16页
Smart specialization is a regional development strategy that identifies regional innovation advantages through the analysis of cluster networks,while strengthening both intra-cluster and inter-cluster technological li... Smart specialization is a regional development strategy that identifies regional innovation advantages through the analysis of cluster networks,while strengthening both intra-cluster and inter-cluster technological linkages to promote coordinated regional development.Drawing on branch office flow and patent cooperation data,and employing methods such as the Expectation-Maximization(EM)clustering algorithm and the‘Product Space’approach,this study investigates innovation and technological linkages both within and across industrial clusters.The key findings are as follows.First,Jiangsu’s clusters demonstrate two patterns:closely integrated industrial networks in southern cities like Suzhou,fostering strong industrial resilience,and distinct technological boundaries in northern and central cities like Yancheng,resulting in weaker integration.Second,the cluster network exhibits a single-core structure at the municipal level,centered around Nanjing,with a multi-tiered hierarchy at the district level.Third,innovation linkages between clusters follow a dual-core structure,with Nanjing and Suzhou as central hubs.In this structure,large enterprises in Nanjing and small and medium-sized enterprises(SMEs)in Suzhou reflect complementary industrial characteristics.Finally,both technology-intensive and low-tech manufacturing industries show a higher propensity for cross-regional innovation,with some cities demonstrating significant advantages in high-tech industries.Grounded in the framework of smart specialization,this study conducts an in-depth analysis of innovation and technological linkages within cluster networks at the industrial level,offering scientific insights to support the localized implementation of smart specialization strategies in the Chinese context. 展开更多
关键词 smart specialization the industry clusters network technological innovation regional development Jiangsu Province China
在线阅读 下载PDF
Ni-W镀层在高含CO_(2)/H_(2)S环境中的腐蚀行为 被引量:1
3
作者 吕祥鸿 曹悦 +4 位作者 汪传磊 薛艳 李杰 刘艳明 代盼 《中国有色金属学报》 北大核心 2025年第5期1660-1673,共14页
采用失重法、表面特性表征以及高温高压电化学测试技术,系统研究Ni-W镀层在模拟地层水环境(高CO_(2)/H_(2)S含量,温度140~180℃)下的高温高压腐蚀行为,同时采用C110钢进行对比实验。结果表明:相较于C110钢,Ni-W镀层展现出更低的均匀腐... 采用失重法、表面特性表征以及高温高压电化学测试技术,系统研究Ni-W镀层在模拟地层水环境(高CO_(2)/H_(2)S含量,温度140~180℃)下的高温高压腐蚀行为,同时采用C110钢进行对比实验。结果表明:相较于C110钢,Ni-W镀层展现出更低的均匀腐蚀速率、点蚀速率以及腐蚀电流密度。Ni-W镀层在140~160℃温度范围内呈现中度腐蚀,在高温180℃时转变为严重腐蚀;相比之下,C110钢在整个测试温度范围内均表现为严重腐蚀,且腐蚀速率远大于Ni-W镀层;Ni-W镀层表面形成的腐蚀产物膜主要由NiS、Ni_(3)S_(2)及微量Ni(OH)_(2)构成,该膜层结构致密,化学稳定性高,与基体结合牢固,且腐蚀产物膜电阻大于C110腐蚀产物FexSy,可有效抑制Ni-W镀层在长期浸泡过程中的腐蚀进程。 展开更多
关键词 Ni-w镀层 高温地层水 CO_(2)/H_(2)s腐蚀 C110钢
在线阅读 下载PDF
W/Cu/S簇基超分子大环及其三阶非线性光学性质 被引量:1
4
作者 黄志文 刘琦 郎建平 《无机化学学报》 北大核心 2025年第1期79-87,共9页
以前驱簇[Et_(4)N][Tp*WS_(3)(CuCl)_(3)]与三氟甲烷磺酸银(AgOTf)及3个有机桥联配体2,5‑二(吡啶‑4‑基)噻吩(L1)、5,5'‑双(4‑吡啶基)‑2,2'‑双噻吩(L_(2))和2,7‑双(4‑吡啶基)芘(L_(3))分别反应,得到了3个阳离子型W/Cu/S簇基超分... 以前驱簇[Et_(4)N][Tp*WS_(3)(CuCl)_(3)]与三氟甲烷磺酸银(AgOTf)及3个有机桥联配体2,5‑二(吡啶‑4‑基)噻吩(L1)、5,5'‑双(4‑吡啶基)‑2,2'‑双噻吩(L_(2))和2,7‑双(4‑吡啶基)芘(L_(3))分别反应,得到了3个阳离子型W/Cu/S簇基超分子大环化合物[(Tp*WS_(3)Cu_(3))_(2)(μ‑Cl)_(2)(μ_(4)‑Cl)(L_(1))]_(2)(OTf)_(2)(1)、[(Tp*WS_(3)Cu_(3))_(2)(μ‑Cl)_(2)(μ_(4)‑Cl)(L_(2))]_(2)(OTf)_(2)·2CHCl_(3)(2·2CHCl_(3))和[(Tp*WS_(3)Cu_(3))_(2)(μ‑Cl)_(2)(μ_(4)‑Cl)(L_(3))]_(2)(OTf)_(2)·2DMF(3·2DMF),其中Tp*=hydridotris(3,5‑dimethylpyrazol‑1‑yl)borate。对3个化合物分别进行了单晶X射线衍射、核磁、质谱、红外光谱、紫外可见光谱和元素分析等结构表征。单晶X射线衍射结果表明,3个大环的主体均是由2个L1、L_(2)和L_(3)配体和3个氯桥连接的[(Tp*WS_(3)Cu_(3))_(2)(μ‑Cl)_(2)(μ_(4)‑Cl)]^(2+)阳离子簇核组成。3个大环通过不同方式堆叠形成三维结构。核磁氢谱(^(1)H NMR)和电喷雾飞行质谱(ESI‑TOF MS)结果表明这些化合物在溶液中有较好的稳定性。Z扫描测试结果表明,3个化合物的溶液有一定的三阶非线性光学响应。 展开更多
关键词 w/Cu/s 组装 超分子大环 结构 三阶非线性光学响应
在线阅读 下载PDF
基于炔/硫环加成反应构筑W/Cu/S簇基超分子及其三阶非线性光学性质
5
作者 王玉杰 王劳棒 +2 位作者 张政 刘琦 郎建平 《无机化学学报》 北大核心 2025年第10期2069-2077,共9页
以(Et_(4)N)[Tp*WS_(3)(CuCl)_(3)](A)(Tp*=三(3,5-二甲基吡唑)氢合硼酸根)为前驱簇,经Ag(OTf)脱氯后,分别与2种含炔基双齿吡啶配体1,3-双[4-(吡啶-4-基乙炔基)苯基]丙烷(L_(1))和1,3-双[4-(吡啶-4-基乙炔基)苯基]丙-2-酮(L_(2))进行自... 以(Et_(4)N)[Tp*WS_(3)(CuCl)_(3)](A)(Tp*=三(3,5-二甲基吡唑)氢合硼酸根)为前驱簇,经Ag(OTf)脱氯后,分别与2种含炔基双齿吡啶配体1,3-双[4-(吡啶-4-基乙炔基)苯基]丙烷(L_(1))和1,3-双[4-(吡啶-4-基乙炔基)苯基]丙-2-酮(L_(2))进行自组装,构筑了2个W/Cu/S簇基超分子矩形大环化合物[(Tp*WS_(3)Cu_(2)Cl)_(4)(L_(1))_(2)]·6CH_(2)Cl_(2)(1·6CH_(2)Cl_(2))和[(Tp*WS_(3)Cu_(2)Cl)_(4)(L_(2))_(2)]·6CH_(2)Cl_(2)(2·6CH_(2)Cl_(2))。在构筑这2个簇合物的过程中,L_(1)或L_(2)中的1个炔基与前驱簇A中2个S发生了不多见的环加成反应,从而形成了1和2簇基超分子矩形大环。在1·6CH_(2)Cl_(2)和2·6CH_(2)Cl_(2)的反应体系中引入吡啶(Py)作为第二配体,获得了新型簇合物[Tp*WS_(3)Cu_(3)(μ_(3)-Cl)(Py)_(3)](OTf)(3)。通过单晶X射线衍射、电喷雾电离质谱、红外光谱、紫外可见光谱和元素分析对3个簇合物进行了系统表征。单晶X射线衍射结果表明,1·6CH_(2)Cl_(2)和2·6CH_(2)Cl_(2)均是由2个双齿配体(L_(1)或L_(2))桥联4个[Tp*WS_(3)Cu_(2)Cl]簇单元形成的簇基超分子矩形大环。簇合物3含有3个吡啶分子配位的阳离子[Tp*WS_(3)Cu_(3)(μ_(3)-Cl)]^(+)类立方烷型结构。采用Z扫描法对簇合物1·6CH_(2)Cl_(2)、2·6CH_(2)Cl_(2)和3的溶液的三阶非线性光学(NLO)性质进行测试,结果表明它们具有良好的三阶NLO响应。 展开更多
关键词 w/Cu/s 炔/硫环加成反应 超分子矩形大环 三阶非线性光学响应
在线阅读 下载PDF
Clinical heterogeneity in patients with early-stage Parkinson’s disease:a cluster analysis 被引量:6
6
作者 Ping LIU Tao FENG +2 位作者 Yong-jun WANG Xuan ZHANG Biao CHEN 《Journal of Zhejiang University-Science B(Biomedicine & Biotechnology)》 SCIE CAS CSCD 2011年第9期694-703,共10页
The aim of this study was to investigate the clinical heterogeneity of Parkinson's disease(PD) among a cohort of Chinese patients in early stages.Clinical data on demographics,motor variables,motor phenotypes,dise... The aim of this study was to investigate the clinical heterogeneity of Parkinson's disease(PD) among a cohort of Chinese patients in early stages.Clinical data on demographics,motor variables,motor phenotypes,disease progression,global cognitive function,depression,apathy,sleep quality,constipation,fatigue,and L-dopa complications were collected from 138 Chinese PD subjects in early stages(Hoehn and Yahr stages 1-3).The PD subject subtypes were classified using k-means cluster analysis according to the clinical data from five-to three-cluster consecutively.Kappa statistical analysis was performed to evaluate the consistency among different subtype solutions.The cluster analysis indicated four main subtypes:the non-tremor dominant subtype(NTD,n=28,20.3%),rapid disease progression subtype(RDP,n=7,5.1%),young-onset subtype(YO,n=50,36.2%),and tremor dominant subtype(TD,n=53,38.4%).Overall,78.3%(108/138) of subjects were always classified between the same three groups(52 always in TD,7 in RDP,and 49 in NTD),and 98.6%(136/138) between five-and four-cluster solutions.However,subjects classified as NTD in the four-cluster analysis were dispersed into different subtypes in the three-cluster analysis,with low concordance between four-and three-cluster solutions(kappa value= 0.139,P=0.001).This study defines clinical heterogeneity of PD patients in early stages using a data-driven approach.The subtypes generated by the four-cluster solution appear to exhibit ideal internal cohesion and external isolation. 展开更多
关键词 Parkinson's disease HETEROGENEITY sUBTYPE cluster analysis
原文传递
Experimental Study of the Interaction between Building Clusters and Flash Floods 被引量:3
7
作者 DU Jun HE Xiao-yan +2 位作者 WANG Zhao-yin ZHANG Chen-di LI Wen-xin 《Journal of Mountain Science》 SCIE CSCD 2015年第5期1334-1344,共11页
In recent years, flash flood disasters have occurred frequently in southwest China due to the increased frequency of extreme climate events. To solve this problem, great efforts have been made in studying the process ... In recent years, flash flood disasters have occurred frequently in southwest China due to the increased frequency of extreme climate events. To solve this problem, great efforts have been made in studying the process of flash flood. However, little attention was paid on bearing body of hazard, the clusters of buildings. Thus the real disaster mechanism of flash flood remains unclear.Accordingly, based on the experiments of artificial flash floods in a conceptual solid model, this paper focuses on the flood-impacted inundation characteristics of the building clusters at different locations of the gully model, in order to obtain a better understanding of the disaster process and the interaction between the flash floods and building clusters. The results showed that, in a typical smallscale flash flood gully with hot and dry climate, 1)clusters of buildings on an alluvial fan could reduce about 35% of the flooding area by blocking the diffusion of the flood to the depression areas, and could also promote the deposition in lower reaches of the river channel by blocking the overbank flow from going back into the channel, making the width-depth ratio of the channel larger. 2) The flash flood rates of disaster and hazard on the alluvial fan are generally higher than that of the inner gully. For the inner gully,buildings located on the beaches along the lower river and the transitional areas of the straight channel and channel bends can easily be affected because of their lower elevations. For the alluvial fan, buildings nearby the meanders suffer the greatest impacts because of bank collapsing and flooding. 3) The safe vertical distance from a building to the river channel is 13 m for the buildings in the inner gully under extreme floods. Below this threshold, the smaller the vertical distance is, the greater the risk exposure is. For the buildings on the alluvial fan, especially for the buildings near the concave bank of the top rush point,the horizontal distance is more important, and the safe value is 80 m under extreme floods. 展开更多
关键词 Flash floods Building clusters settlement's distribution Disaster process Fieldmodel experiment
原文传递
Cluster synchronization in a network of non-identical dynamic systems 被引量:2
8
作者 吴建设 焦李成 陈关荣 《Chinese Physics B》 SCIE EI CAS CSCD 2011年第6期78-88,共11页
Cluster synchronization in a network of non-identical dynamic systems is studied in this paper, using two-cluster synchronization for detailed analysis and discussion. The results show that the common intercluster cou... Cluster synchronization in a network of non-identical dynamic systems is studied in this paper, using two-cluster synchronization for detailed analysis and discussion. The results show that the common intercluster coupling condition is not always needed for the diffusively coupled network. Several sufficient conditions are obtained by using the Schur unitary triangularization theorem, which extends previous results. Some numerical examples are presented for illustration. 展开更多
关键词 complex network cluster synchronization diffusive couplings schur's theorem
原文传递
Evolutionary prisoner's dilemma game on highly clustered community networks 被引量:1
9
作者 刘永奎 李智 +1 位作者 陈小杰 王龙 《Chinese Physics B》 SCIE EI CAS CSCD 2009年第7期2623-2628,共6页
This paper studies the evolutionary prisoner's dilemma game on a highly clustered community network in which the clustering coefficient and the community size can be tuned. It finds that the clustering coefficient in... This paper studies the evolutionary prisoner's dilemma game on a highly clustered community network in which the clustering coefficient and the community size can be tuned. It finds that the clustering coefficient in such a degree-homogeneous network inhibits the emergence of cooperation for the entire range of the payoff parameter. Moreover, it finds that the community size can also have a marked influence on the evolution of cooperation, with a larger community size leading to not only a lower cooperation level but also a smaller threshold of the payoff parameter above which cooperators become extinct. 展开更多
关键词 prisoner's dilemma COOPERATION clustering coefficient community structure
原文传递
自集成黑色NiO团簇与ZnIn_(2)S_(4)微球实现S型电子转移机制下光热辅助制氢
10
作者 葛成艳 胡佳伟 +3 位作者 刘星雨 宋玉玺 刘超 邹志刚 《物理化学学报》 北大核心 2026年第1期115-129,共15页
利用太阳能制氢(H_(2))技术是实现碳中和目标的关键策略,但是设计最优异质结构光催化剂仍面临重大挑战。本研究首次在溶剂热过程中成功实现了高度分散的黑色NiO团簇与ZIS微球的自组装。所构建的NiO/ZIS S型异质结构复合材料可提供更多... 利用太阳能制氢(H_(2))技术是实现碳中和目标的关键策略,但是设计最优异质结构光催化剂仍面临重大挑战。本研究首次在溶剂热过程中成功实现了高度分散的黑色NiO团簇与ZIS微球的自组装。所构建的NiO/ZIS S型异质结构复合材料可提供更多活性位点用于可见光驱动光催化产氢(PHE)反应。最优样品2-NiO/ZIS表现出2474.0μmol g^(-1)h^(-1)的最佳产氢速率、36.67%的最高表观量子产率(AQY)以及优异的结构稳定性。此外,NiO/ZIS复合材料在天然海水中也展现出高产氢活性。通过原位X射线光电子能谱(XPS)、水相时间分辨光致发光光谱(TRPL)和瞬态吸收光谱(TAS)等先进表征技术,系统评估了催化剂的电荷分离行为。实验分析与理论计算结果共同阐明了NiO/ZIS的S型电荷转移机制。提升的PHE活性源于黑色NiO团簇与ZIS之间的协同效应,包括增强光捕获能力、加速载流子传输与分离、保持高氧化还原能力以及改善表面反应动力学。本研究为构建具有光热效应的S型异质结构复合材料提供了新思路。 展开更多
关键词 s型异质结 NiO团簇 ZnIn_(2)s_(4) 光热效应 产氢
在线阅读 下载PDF
Syntheses and Characterization of Two Novel Mo(W)/Cu/S Dodecanuclear Clusters with Triple Incomplete Cubane-like Structure
11
作者 李建荣 林平 +1 位作者 李志华 杜少武 《Chinese Journal of Structural Chemistry》 SCIE CAS CSCD 2009年第11期1475-1479,共5页
The self-assembly reactions of [MOS3]^2- (M = W, Mo) with CuS2COCH3 in DMF produced two novel dodecanuclear Mo(W)/Cu/S heterometallic clusters, [Et4N]4[{MOS3}3Cu6S2- (CuS2COCH3)3]·H2O (1: M = W; 2: M = M... The self-assembly reactions of [MOS3]^2- (M = W, Mo) with CuS2COCH3 in DMF produced two novel dodecanuclear Mo(W)/Cu/S heterometallic clusters, [Et4N]4[{MOS3}3Cu6S2- (CuS2COCH3)3]·H2O (1: M = W; 2: M = Mo). Cluster 1 crystallizes in hexagonal, space group P-62c with a = 16.5612(3), b = 16.5612(3), c = 16.4660(5)A, Z = 2, V = 3911.13(16)A^3, Dc = 1.935 g/cm^3, μ(MoKα) = 7.269 mm^-1, F(000) = 2192, the final R = 0.0289 and wR = 0.0789 for 2425 observed reflections (I 〉 2σ(I)). Cluster 2 is isomorphous to 1 with similar crystal parameters. X-ray analysis reveals that both clusters consist of three incomplete cubane-like cluster units {MOS3Cu3S2COCH3}, which are linked together by two μ3-S atoms. 展开更多
关键词 thioltungstate thiomolybdate dececanuclear Mo(w)/Cu/s clusters crystal structure
在线阅读 下载PDF
基于TimeVAE的1DCNN-S-Mamba组合模型光伏功率短期预测
12
作者 许可证 文中 王秋杰 《热力发电》 北大核心 2026年第1期122-133,共12页
针对极端天气下光伏功率预测存在的气象响应失准、突变特征捕捉困难及数据稀缺等问题,提出一种基于模糊C均值(fuzzy C-means,FCM)、最大信息系数(maximum information coefficient,MIC)、时序变分自编码器(time variational auto-encode... 针对极端天气下光伏功率预测存在的气象响应失准、突变特征捕捉困难及数据稀缺等问题,提出一种基于模糊C均值(fuzzy C-means,FCM)、最大信息系数(maximum information coefficient,MIC)、时序变分自编码器(time variational auto-encoders,TimeVAE)、一维卷积神经网络(1D convolutional neural network,1DCNN)和simple-Mamba(S-Mamba)的组合功率预测模型。首先,通过气象特征结合FCM聚类将天气划分为晴天、多云、降雪和降雨4类;然后,结合MIC筛选出最佳气象特征子集,同时针对极端天气样本匮乏问题,采用Time VAE进行数据生成,利用其分解式重构机制生成仿真数据;最后,使用1DCNN-S-Mamba组合模型通过局部卷积捕获短时突变特征,结合双向状态空间建模实现长程依赖解析进行预测。实验结果表明,该模型提升了复杂天气下光伏功率预测的时效性与准确性。相较于S-Mamba,所提模型平均绝对误差和均方根误差在降雪天气下分别降低了3.65%和5.10%。 展开更多
关键词 模糊聚类 时序变分自编码器 数据增强 一维卷积神经网络 s-Mamba
在线阅读 下载PDF
A New Ionic Trimolybdenum Cluster Compound:〔Mo_3S_7(S_2P(iprO)_2)_3〕〔S_2P(iprO)_2〕 被引量:1
13
作者 YU Rong-Min LU Shao-Fang +2 位作者 HUANG Xiao-Ying WU Qiang-Jin HUANG Jian-Quan(State Key Laboratory of Structural Chemistry, Fujian Institute of Research on the Structureof Matter, Chinese Academy Of Sciences, Fuzhou, 350002, China) 《Chinese Journal of Structural Chemistry》 SCIE CAS CSCD 1998年第2期137-141,共5页
The title compound ttris-(diisopropyldithiophosphato)tris-μ-disulfidoμ3,-sulfido-cvclo-trimolybdenumj (3Mo-Mo) [diisopropyldithiophosphate], [Mo3S7 (S2P(iprO)2)3] [S2P(iprO)2] (Mr=1365. 39) is an ionic species which... The title compound ttris-(diisopropyldithiophosphato)tris-μ-disulfidoμ3,-sulfido-cvclo-trimolybdenumj (3Mo-Mo) [diisopropyldithiophosphate], [Mo3S7 (S2P(iprO)2)3] [S2P(iprO)2] (Mr=1365. 39) is an ionic species which consists of a discretecluster cation [Mo3S7 (S2P (iprO)2)3] + (ipr = isopropyl) and an anion [S2P (iprO)2]-It was synthesized from the reaction of (NH4)2MoS4 with HS2P (iprO)2. Crystallo-graphic data for its crystal: space group for 7356 independent reflec-'tions with The structure analysis reveals that the cation contains a typical(Mo3 (μ3,-S) (μ-S2)3]+ cluster core in which three molybdenum atoms form an isoscelestriangle;the structure of the free diisopropyldithiophosphate anion [S2P (iprO)2]- isdifferent obviously from the coordinated one. 展开更多
关键词 Mo-s cluster ionic cluster sTRUCTURE
在线阅读 下载PDF
Syntheses,Structures and Spectroscopic Properties of Mo(W)-Cu-S-Cluster Compounds with Dialkyldithiocarbamate Ligands
14
作者 Cao Rong Lei Xin-Jian +5 位作者 Hong Mao-Chun Xie Xiu-Lan Kang Bei-Sheng Jiang Fei-Long Liu Qiu-Tian Liu Han-Qin(State Key Labofratory of Structural Chemistry and Fujian Institute of Research on the Structure of Matter,Chinese Academy of Sciences,Fuzhou,Fujian 3500 《Chinese Journal of Structural Chemistry》 SCIE CAS CSCD 1995年第6期33-43,共11页
This paper presents the synthetic and structure studies of molybdenum(tungsten)-copper-sulphur-dialkyldithiocarbamate cluster compounds.The reactions of(M=Mo,W;n=0,2),CuCl,and R<sub>2</sub>dtc ̄-(R<... This paper presents the synthetic and structure studies of molybdenum(tungsten)-copper-sulphur-dialkyldithiocarbamate cluster compounds.The reactions of(M=Mo,W;n=0,2),CuCl,and R<sub>2</sub>dtc ̄-(R<sub>2</sub>=Me<sub>2</sub>,Et<sub>2</sub>,C<sub>4</sub>H<sub>8</sub>,C<sub>5</sub>H<sub>1</sub>0) yield a series of tetra-,hexa-,and heptanuclear cluster compounds.Their spectroscopic properties and the synthetic reaction mechanism are discussed. 展开更多
关键词 Mo(w)-Cu-s cluster compounds dialkyldithiocarbamate(R<sub>2</sub>dtc) sTRUCTUREs reaction mechanism
在线阅读 下载PDF
Synthesis and crystal structure and nonlinear optical properties of polymeric W (Mo)-Cu-S cluster
15
作者 周建良 陈启元 +1 位作者 古映莹 钟世安 《中国有色金属学会会刊:英文版》 CSCD 2006年第B01期178-182,共5页
The polymeric chalcogenide [W2O2S6Cu4(NCMe)4]n (compound 1) was synthesized by the self-assembly reaction of (NH4)2(WOS3) with CuBr in MeCN in the presence of tricyclohexylphosphane (PCy3) under a purified nitrogen at... The polymeric chalcogenide [W2O2S6Cu4(NCMe)4]n (compound 1) was synthesized by the self-assembly reaction of (NH4)2(WOS3) with CuBr in MeCN in the presence of tricyclohexylphosphane (PCy3) under a purified nitrogen atmosphere using standard Schlenk techniques. It gives rise to a novel 1D polymeric compound 1 with solvent MeCN coordinated to the copper atom. This situation is unprecedented in the W(Mo)/Cu/S system. The crystals were characterized by elemental analysis, IR and single-crystal X-ray crystallography. The configuration of the polymeric compound can be viewed as a helical chain which is propagated along the crystallographic c axis. The excited state absorption and refraction of compound 1 in CH3CN solution were studied by using the Z-scan technique with laser pulses of 40 ps pulse-width at a wavelength of 532 nm. The polymeric compound possesses an optical self-focusing performance. The positive nonlinear refraction is attributed to population transitions between singlet states. Compound 1 displays a strong excited-state absorption. 展开更多
关键词 w(Mo)-Cu-s团簇 硫属化物 自组装 激发态 合成 晶体结构 非线性光学性质
在线阅读 下载PDF
基于Kendall's W系数的交叉效率共识一致性模型
16
作者 郭冬 徐文龙 +1 位作者 周洋 张艳秋 《安徽建筑大学学报》 2025年第6期53-61,共9页
交叉效率评价方法将自我评价与同行评价相结合,弥补了传统CCR模型无法完全排序的缺点,但在评价过程中没有考虑决策单元之间的共识。利用Kendall's W系数构建一个交叉效率共识一致性模型,使决策单元在聚合过程中达成最大共识。首先,... 交叉效率评价方法将自我评价与同行评价相结合,弥补了传统CCR模型无法完全排序的缺点,但在评价过程中没有考虑决策单元之间的共识。利用Kendall's W系数构建一个交叉效率共识一致性模型,使决策单元在聚合过程中达成最大共识。首先,用交叉效率模型得到交叉效率矩阵。然后,根据最小调整共识模型和Kendall's W系数提出共识一致性模型,提高交叉效率聚合过程中决策单元之间的共识一致性程度。最后,通过实例说明和验证所提出共识机制的适用性。结果表明,共识调整后与传统聚合的排序具有显著差异,显示出更强的共识一致性。 展开更多
关键词 数据包络分析 交叉效率 共识一致性 Kendall’s w系数
在线阅读 下载PDF
The role of sulfur cycle in new particle formation:Cycloaddition reaction of SO_(3)to H_(2)S
17
作者 Haijie Zhang Wei Wang +5 位作者 Liang Fan Junling Li Yanqin Ren Hong Li Rui Gao Yisheng Xu 《Journal of Environmental Sciences》 2025年第2期489-501,共13页
The chemistry of sulfur cycle contributes significantly to the atmospheric nucleation process,which is the first step of new particle formation(NPF).In the present study,cycloaddition reaction mechanism of sulfur trio... The chemistry of sulfur cycle contributes significantly to the atmospheric nucleation process,which is the first step of new particle formation(NPF).In the present study,cycloaddition reaction mechanism of sulfur trioxide(SO_(3))to hydrogen sulfide(H_(2)S)which is a typical air pollutant and toxic gas detrimental to the environment were comprehensively investigate through theoretical calculations and Atmospheric Cluster Dynamic Code simulations.Gas-phase stability and nucleation potential of the product thiosulfuric acid(H_(2)S_(2)O_(3),TSA)were further analyzed to evaluate its atmospheric impact.Without any catalysts,the H_(2)S+SO_(3)reaction is infeasible with a barrier of 24.2 kcal/mol.Atmospheric nucleation precursors formic acid(FA),sulfuric acid(SA),and water(H_(2)O)could effectively lower the reaction barriers as catalysts,even to a barrierless reaction with the efficiency of cis-SA>trans-FA>trans-SA>H_(2)O.Subsequently,the gas-phase stability of TSA was investigated.A hydrolysis reaction barrier of up to 61.4 kcal/mol alone with an endothermic isomerization reaction barrier of 5.1 kcal/mol under the catalytic effect of SA demonstrates the sufficient stability of TSA.Furthermore,topological and kinetic analysis were conducted to determine the nucleation potential of TSA.Atmospheric clusters formed by TSA and atmospheric nucleation precursors(SA,ammonia NH_(3),and dimethylamine DMA)were thermodynamically stable.Moreover,the gradually decreasing evaporation coefficients for TSA-base clusters,particularly for TSA-DMA,suggests that TSA may participate in NPF where the concentration of base molecules are relatively higher.The present new reaction mechanismmay contributes to a better understanding of atmospheric sulfur cycle and NPF. 展开更多
关键词 New particle formation(NPF) Atmospheric sulfur cycle Nucleation process Reaction mechanism Hydrogen sulfide(H_(2)s) Atmospheric cluster Dynamic Code (ACDC)
原文传递
Energy-Efficient Clustering Using Optimization with Locust Game Theory
18
作者 P.Kavitha Rani Hee-Kwon Chae +1 位作者 Yunyoung Nam Mohamed Abouhawwash 《Intelligent Automation & Soft Computing》 SCIE 2023年第6期2591-2605,共15页
Wireless sensor networks(WSNs)are made up of several sensors located in a specific area and powered by a finite amount of energy to gather environmental data.WSNs use sensor nodes(SNs)to collect and transmit data.Howe... Wireless sensor networks(WSNs)are made up of several sensors located in a specific area and powered by a finite amount of energy to gather environmental data.WSNs use sensor nodes(SNs)to collect and transmit data.However,the power supplied by the sensor network is restricted.Thus,SNs must store energy as often as to extend the lifespan of the network.In the proposed study,effective clustering and longer network lifetimes are achieved using mul-ti-swarm optimization(MSO)and game theory based on locust search(LS-II).In this research,MSO is used to improve the optimum routing,while the LS-II approach is employed to specify the number of cluster heads(CHs)and select the best ones.After the CHs are identified,the other sensor components are allo-cated to the closest CHs to them.A game theory-based energy-efficient clustering approach is applied to WSNs.Here each SN is considered a player in the game.The SN can implement beneficial methods for itself depending on the length of the idle listening time in the active phase and then determine to choose whether or not to rest.The proposed multi-swarm with energy-efficient game theory on locust search(MSGE-LS)efficiently selects CHs,minimizes energy consumption,and improves the lifetime of networks.The findings of this study indicate that the proposed MSGE-LS is an effective method because its result proves that it increases the number of clusters,average energy consumption,lifespan extension,reduction in average packet loss,and end-to-end delay. 展开更多
关键词 wireless sensor network clusterING routing cluster head energy consumption network’s lifetime multi swarm optimization game theory
在线阅读 下载PDF
上一页 1 2 67 下一页 到第
使用帮助 返回顶部