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Molecular network-based intervention brings us closer to ending the HIV pandemic

Xiaoxu Han, Bin Zhao, Minghui An, Ping Zhong, Hong Shang

《医学前沿(英文)》 2020年 第14卷 第2期   页码 136-148 doi: 10.1007/s11684-020-0756-y

摘要: Precise identification of HIV transmission among populations is a key step in public health responses. However, the HIV transmission network is usually difficult to determine. HIV molecular networks can be determined by phylogenetic approach, genetic distance-based approach, and a combination of both approaches. These approaches are increasingly used to identify transmission networks among populations, reconstruct the history of HIV spread, monitor the dynamics of HIV transmission, guide targeted intervention on key subpopulations, and assess the effects of interventions. Simulation and retrospective studies have demonstrated that these molecular network-based interventions are more cost-effective than random or traditional interventions. However, we still need to address several challenges to improve the practice of molecular network-guided targeting interventions to finally end the HIV epidemic. The data remain limited or difficult to obtain, and more automatic real-time tools are required. In addition, molecular and social networks must be combined, and technical parameters and ethnic issues warrant further studies.

关键词: human immunodeficiency virus type 1     molecular cluster     transmission cluster     risk network     targeted intervention     evaluation    

A density functional theory study of the adsorption of Hg and HgCl2 on a CaO(001) surface

GUO Xin, ZHENG Chuguang, LU Nanxia

《能源前沿(英文)》 2007年 第1卷 第1期   页码 101-104 doi: 10.1007/s11708-007-0011-0

摘要: The adsorption of mercury and mercury chloride on a CaO(001) surface was investigated by the density functional theory (DFT) by using CaO cluster embedded in an electrostatic field represented by 178 point charges at the crystal CaO lattice positions. For the mercury molecular axis normal to the surface, the mercury can only coordinate to the O anion and has a very weak binding energy of 19.649 kJ/mol. When the mercury chloride molecular axis is vertical to the surface, the Cl atom coordinates to the Ca cation and has a binding energy of 23.699 kJ/mol. When the mercury chloride molecular axis is parallel to the surface, the Hg atom coordinates to the O anion and has a binding energy of 87.829 kJ/mol, which means that the parallel geometry is more stable than the vertical one. The present calculations show that CaO injection could substantially reduce gaseous mercury chloride, but have no apparent effect on the mercury, which is compatible with the available experimental results. This research will provide valuable information for optimizing and selecting a sorbent for the trace element in flue gas.

关键词: mercury chloride     mercury molecular     surface     cluster     electrostatic    

Molecular dynamics simulations of initial Pd and PdO nanocluster growth in a magnetron gas aggregation

Pascal Brault, William Chamorro-Coral, Sotheara Chuon, Amaël Caillard, Jean-Marc Bauchire, Stève Baranton, Christophe Coutanceau, Erik Neyts

《化学科学与工程前沿(英文)》 2019年 第13卷 第2期   页码 324-329 doi: 10.1007/s11705-019-1792-5

摘要: Molecular dynamics simulations are carried out for describing growth of Pd and PdO nanoclusters using the ReaxFF force field. The resulting nanocluster structures are successfully compared to those of nanoclusters experimentally grown in a gas aggregation source. The PdO structure is quasi-crystalline as revealed by high resolution transmission microscope analysis for experimental PdO nanoclusters. The role of the nanocluster temperature in the molecular dynamics simulated growth is highlighted.

关键词: molecular dynamics     cluster growth     plasma sputtering     nanocatalyst    

Design of tandem genes cluster for isoflavone engineering

Xunli XIA PhD , Guangxiao YANG PhD , Guangyuan HE PhD ,

《医学前沿(英文)》 2009年 第3卷 第3期   页码 292-296 doi: 10.1007/s11684-009-0057-y

摘要: In this paper, a universal effective novel method of constructing tandem genes cluster for isoflavone engineering was reported. A tandem genes cluster () of secondary metabolites of plant isoflavones was constructed by using the chalcone synthase (CHS), chalcone isomerase (CHI), and isoflavone synthase (IFS) (GenBank accession numbers EU526827, EU526829, EU526830) in only one recombination with the pET22b vector. The resulting expression vector pET- was heterogeneously expressed and co-incubated with barrenwort extractions, and the genistein-like component was detected.

关键词: isoflavones engineering     secondary metabolism     tandem genes cluster    

Understanding high-emitting households in the UK through a cluster analysis

Xinfang WANG, Ming MENG

《能源前沿(英文)》 2019年 第13卷 第4期   页码 612-625 doi: 10.1007/s11708-019-0647-6

摘要: Anthropogenic climate change is a global problem that affects every country and each individual. It is largely caused by human beings emitting greenhouse gases into the atmosphere. In general, a small percentage of the population is responsible for a large amount of emissions. This paper focuses on high emitters and their CO emissions from energy use in UK homes. It applies a cluster approach, aiming to identify whether the high emitters comprise clusters where households in each cluster share similar characteristics but are different from the others. The data are mainly based on the Living Cost and Food survey in the UK. The results show that after equivalising both household emissions and income, the high emitters can be clustered into six groups which share similar characteristics within each group, but are different from the others in terms of income, age, household composition, category and size of the dwelling, and tenure type. The clustering results indicate that various combinations of socioeconomic factors, such as low-income single female living in an at least six-room property, or high-income retired couple owning a large detached house, could all lead to high CO emissions from energy use at home. Policymakers should target each high-emitter cluster differently to reduce CO emissions from energy consumption at home more effectively.

关键词: cluster analysis     emissions reduction     energy use     high emitters     household energy consumption     socioeconomic factors    

Scaling up of cluster beam deposition technology for catalysis application

《化学科学与工程前沿(英文)》 2021年 第15卷 第6期   页码 1360-1379 doi: 10.1007/s11705-021-2101-7

摘要: Many research works have demonstrated that the combination of atomically precise cluster deposition and theoretical calculations is able to address fundamental aspects of size-effects, cluster-support interactions, and reaction mechanisms of cluster materials. Although the wet chemistry method has been widely used to synthesize nanoparticles, the gas-phase synthesis and size-selected strategy was the only method to prepare supported metal clusters with precise numbers of atoms for a long time. However, the low throughput of the physical synthesis method has severely constrained its wider adoption for catalysis applications. In this review, we introduce the latest progress on three types of cluster source which have the most promising potential for scale-up, including sputtering gas aggregation source, pulsed microplasma cluster source, and matrix assembly cluster source. While the sputtering gas aggregation source is leading ahead with a production rate of ~20 mg·h–1, the pulsed microplasma source has the smallest physical dimensions which makes it possible to compact multiple such devices into a small volume for multiplied production rate. The matrix assembly source has the shortest development history, but already show an impressive deposition rate of ~10 mg·h–1. At the end of the review, the possible routes for further throughput scale-up are envisaged.

关键词: nanoparticle     cluster     cluster beam deposition     magnetron sputtering     heterogeneous catalysis    

圆锥滚子轴承振动的灰色模糊聚类分析

刘劲军,夏新涛,张立红

《中国工程科学》 2008年 第10卷 第7期   页码 112-117

摘要:

以30204型圆锥滚子轴承试验数据为基础,利用灰色模糊聚类分析方法对影响圆锥滚子轴承振动的 因素进行了综合分析,将圆锥滚子轴承各项参数按其对振动的影响分为三类:第一类对振动的影响最大,其 中包括滚子凸度、滚子直径偏差Dw 等参数;第二类对振动的影响较大,其中包括内滚道圆度,内滚道直线性 Li 等参数;第三类对振动的影响最小,其中包括内滚道波纹度,内滚道的角度偏差Δ2β 等参数。根据分类可 知,试验中圆锥滚子轴承的大部分参数都会对振动产生较大的影响。

关键词: 圆锥滚子轴承     振动     灰色模糊聚类分析    

Cluster voltage control method for “Whole County” distributed photovoltaics based on improved differential

《能源前沿(英文)》   页码 782-795 doi: 10.1007/s11708-023-0905-8

摘要: China is vigorously promoting the “whole county promotion” of distributed photovoltaics (DPVs). However, the high penetration rate of DPVs has brought problems such as voltage violation and power quality degradation to the distribution network, seriously affecting the safety and reliability of the power system. The traditional centralized control method of the distribution network has the problem of low efficiency, which is not practical enough in engineering practice. To address the problems, this paper proposes a cluster voltage control method for distributed photovoltaic grid-connected distribution network. First, it partitions the distribution network into clusters, and different clusters exchange terminal voltage information through a “virtual slack bus.” Then, in each cluster, based on the control strategy of “reactive power compensation first, active power curtailment later,” it employs an improved differential evolution (IDE) algorithm based on Cauchy disturbance to control the voltage. Simulation results in two different distribution systems show that the proposed method not only greatly improves the operational efficiency of the algorithm but also effectively controls the voltage of the distribution network, and maximizes the consumption capacity of DPVs based on qualified voltage.

关键词: distributed photovoltaics (DPVs)     cluster partitioning     improved differential evolution algorithm     voltage control     consumption capacity of distributed photovoltaics    

Determination of the principal factors of river water quality through cluster analysis method and its

Liang GUO, Ying ZHAO, Peng WANG

《环境科学与工程前沿(英文)》 2012年 第6卷 第2期   页码 238-245 doi: 10.1007/s11783-011-0382-7

摘要: In this paper, an artificial neural network model was built to predict the Chemical Oxygen Demand (COD ) measured by permanganate index in Songhua River. To enhance the prediction accuracy, principal factors were determined through the analysis of the weight relation between influencing factors and forecasting object using cluster analysis method, which optimized the topological structure of the prediction model input items of the artificial neural network. It was shown that application of the principal factors in water quality prediction model can improve its forecasting skill significantly through the comparison between results of prediction by artificial neural network and the measurements of the COD . This methodology is also applicable to various water quality prediction targets of other water bodies and it is valuable for theoretical study and practical application.

关键词: water quality forecast     principal factor     cluster analysis method     artificial neural network    

A density functional theory study of methane activation on MgO supported NiM cluster: role of M on C–H

《化学科学与工程前沿(英文)》 2022年 第16卷 第10期   页码 1485-1492 doi: 10.1007/s11705-022-2169-8

摘要: Methane activation is a pivotal step in the application of natural gas converting into high-value added chemicals via methane steam/dry reforming reactions. Ni element was found to be the most widely used catalyst. In present work, methane activation on MgO supported Ni–M (M = Fe, Co, Cu, Pd, Pt) cluster was explored through detailed density functional theory calculations, compared to pure Ni cluster. CH4 adsorption on Cu promoted Ni cluster requires overcoming an energy of 0.07 eV, indicating that it is slightly endothermic and unfavored to occur, while the adsorption energies of other promoters M (M = Fe, Co, Pd and Pt) are all higher than that of pure Ni cluster. The role of M on the first C–H bond cleavage of CH4 was investigated. Doping elements of the same period in Ni cluster, such as Fe, Co and Cu, for C–H bond activation follows the trend of the decrease of metal atom radius. As a result, Ni–Fe shows the best ability for C–H bond cleavage. In addition, doping the elements of the same family, like Pd and Pt, for CH4 activation is according to the increase of metal atom radius. Consequently, C–H bond activation demands a lower energy barrier on Ni–Pt cluster. To illustrate the adsorptive dissociation behaviors of CH4 at different Ni–M clusters, the Mulliken atomic charge was analyzed. In general, the electron gain of CH4 binding at different Ni–M clusters follows the sequence of Ni–Cu (–0.02 e) < Ni (–0.04 e) < Ni–Pd (–0.08 e) < Ni–Pt (–0.09 e) < Ni–Co (–0.10 e) < Ni–Fe (–0.12 e), and the binding strength between catalysts and CH 4 raises with the CH4 electron gain increasing. This work provides insights into understanding the role of promoter metal M on thermal-catalytic activation of CH4 over Ni/MgO catalysts, and is useful to interpret the reaction at an atomic scale.

关键词: CH4 dissociation     Ni–M     C–H bond activation     charge transfer    

Special issue on “Molecular Sensors and Molecular Logic Gates”

Luling Wu , Tony D. James

《化学科学与工程前沿(英文)》 2022年 第16卷 第1期   页码 1-3 doi: 10.1007/s11705-021-2134-y

Design of bio-oil additives via molecular signature descriptors using a multi-stage computer-aided molecular

《化学科学与工程前沿(英文)》 2022年 第16卷 第2期   页码 168-182 doi: 10.1007/s11705-021-2056-8

摘要: Direct application of bio-oil from fast pyrolysis as a fuel has remained a challenge due to its undesirable attributes such as low heating value, high viscosity, high corrosiveness and storage instability. Solvent addition is a simple method for circumventing these disadvantages to allow further processing and storage. In this work, computer-aided molecular design tools were developed to design optimal solvents to upgrade bio-oil whilst having low environmental impact. Firstly, target solvent requirements were translated into measurable physical properties. As different property prediction models consist different levels of structural information, molecular signature descriptor was used as a common platform to formulate the design problem. Because of the differences in the required structural information of different property prediction models, signatures of different heights were needed in formulating the design problem. Due to the combinatorial nature of higher-order signatures, the complexity of a computer-aided molecular design problem increases with the height of signatures. Thus, a multi-stage framework was developed by developing consistency rules that restrict the number of higher-order signatures. Finally, phase stability analysis was conducted to evaluate the stability of the solvent-oil blend. As a result, optimal solvents that improve the solvent-oil blend properties while displaying low environmental impact were identified.

关键词: computer-aided molecular design     bio-oil additives     molecular signature descriptor    

Progress on molecular biomarkers and classification of malignant gliomas

null

《医学前沿(英文)》 2013年 第7卷 第2期   页码 150-156 doi: 10.1007/s11684-013-0267-1

摘要:

Gliomas are the most common primary intracranial tumors in adults. Anaplastic gliomas (WHO grade III) and glioblastomas (WHO grade IV) represent the major groups of malignant gliomas in the brain. Several diagnostic, predictive, and prognostic biomarkers for malignant gliomas have been reported over the last few decades, and these markers have made great contributions to the accuracy of diagnosis, therapeutic decision making, and prognosis of patients. However, heterogeneity in patient outcomes may still be observed, which highlights the insufficiency of a classification system based purely on histopathology. Great efforts have been made to incorporate new information about the molecular landscape of gliomas into novel classifications that may potentially guide treatment. In this review, we summarize three distinctive biomarkers, three most commonly altered pathways, and three classifications based on microarray data in malignant gliomas.

关键词: malignant glioma     molecular biomarker     IDH1     MGMT     molecular classification    

Molecular classification and molecular targeted therapy of cancer

null

《医学前沿(英文)》 2013年 第7卷 第2期   页码 147-149 doi: 10.1007/s11684-013-0274-2

Monte Carlo simulation of the diffusion-limited aggregating process of particle suspension systems

Jiajing XU, Lin ZHANG, Yongjian TANG, Wei DAI, Wenwen SHAN,

《化学科学与工程前沿(英文)》 2010年 第4卷 第3期   页码 270-274 doi: 10.1007/s11705-009-0273-7

摘要: The aggregating process of particle suspension systems is a very universal phenomena and crucial for various processes both in nature and in industry. In this paper, the aggregating process was simulated with off-lattice diffusion-limited cluster-cluster aggregation (DLCA) Monte Carlo programs. The self-similar fractal structures of aggregates have been clearly demonstrated by the statistical analysis of gyration radius distribution and the existence of a scaling distribution of the reduced cluster size. The fractal dimension determined from the relationship between mass and gyration radius of aggregates was 1.80 or so. The fractal dimension of the aggregates drawn from the radial distribution function and structure factor of a single aggregate is about 1.90–2.10. It was also showed that, along with the increasing of particle volume fraction, the fractal dimension will increase in a nearly square root manner, and the spatial range of the fractal structure appearing becomes narrower. Also, the gelation transition can only occur in a particle suspension system where the particle volume fraction is greater than a critical value.

关键词: cluster-cluster aggregation     distribution function     relationship     process     universal    

标题 作者 时间 类型 操作

Molecular network-based intervention brings us closer to ending the HIV pandemic

Xiaoxu Han, Bin Zhao, Minghui An, Ping Zhong, Hong Shang

期刊论文

A density functional theory study of the adsorption of Hg and HgCl2 on a CaO(001) surface

GUO Xin, ZHENG Chuguang, LU Nanxia

期刊论文

Molecular dynamics simulations of initial Pd and PdO nanocluster growth in a magnetron gas aggregation

Pascal Brault, William Chamorro-Coral, Sotheara Chuon, Amaël Caillard, Jean-Marc Bauchire, Stève Baranton, Christophe Coutanceau, Erik Neyts

期刊论文

Design of tandem genes cluster for isoflavone engineering

Xunli XIA PhD , Guangxiao YANG PhD , Guangyuan HE PhD ,

期刊论文

Understanding high-emitting households in the UK through a cluster analysis

Xinfang WANG, Ming MENG

期刊论文

Scaling up of cluster beam deposition technology for catalysis application

期刊论文

圆锥滚子轴承振动的灰色模糊聚类分析

刘劲军,夏新涛,张立红

期刊论文

Cluster voltage control method for “Whole County” distributed photovoltaics based on improved differential

期刊论文

Determination of the principal factors of river water quality through cluster analysis method and its

Liang GUO, Ying ZHAO, Peng WANG

期刊论文

A density functional theory study of methane activation on MgO supported NiM cluster: role of M on C–H

期刊论文

Special issue on “Molecular Sensors and Molecular Logic Gates”

Luling Wu , Tony D. James

期刊论文

Design of bio-oil additives via molecular signature descriptors using a multi-stage computer-aided molecular

期刊论文

Progress on molecular biomarkers and classification of malignant gliomas

null

期刊论文

Molecular classification and molecular targeted therapy of cancer

null

期刊论文

Monte Carlo simulation of the diffusion-limited aggregating process of particle suspension systems

Jiajing XU, Lin ZHANG, Yongjian TANG, Wei DAI, Wenwen SHAN,

期刊论文