Subjects: Digital Publishing >> New Media submitted time 2023-10-08 Cooperative journals: 《中国传媒科技》
Abstract：电视节目是人们日常生活娱乐中的重要组成,对人们精神生活的质量有着很大的影响。而电视台节目的正常播出离不开电视台机房安全播出技术的支持。随着现代技术的发展,对电视台机房安全播出技术提出了更高的要求,因此,为了提高电视台机房安全播出技术水平,进一步优化电视节目的播放效果,本文以电视台为背景,分析了影响其安全播出的因素及机房安全播出技术的作用,最后也提出了几点技术保障措施,以期为推动电视广播事业的发展做出应有贡献。
Subjects: Digital Publishing >> New Media submitted time 2023-10-08 Cooperative journals: 《中国传媒科技》
Abstract：随着社会进步和各地区经济的发展,广播电视模拟技术正在逐步被淘汰,各类新兴技术的使用使广播电视整体的运转效率提升了很多,多画面分割器就是其中一个重要代表。笔者试图对此展开研究,探索其在广播电视系统中的应用。
Subjects: Digital Publishing >> New Media submitted time 2023-10-08 Cooperative journals: 《中国传媒科技》
Abstract：本文首先简要介绍了毫米波在频谱、产业链等方面的发展情况,然后提出一种基于Opto-DMD的新型光生毫米波装置,装置可生成17.23GHz～137.36GHz频段的毫米波信号,同时对其核心器件Opto-DMD进行了简单介绍,接着对光生毫米波过程中涉及的关键过程进行理论分析,包括游标效应、四波混频和光学外差法等,最后分析了毫米波的优劣势,并提出广电5G毫米波部署场景建议。
Subjects: Library Science，Information Science >> Information Science submitted time 2023-04-01 Cooperative journals: 《图书情报工作》
Abstract： [Purpose/significance] The lack of research data metadata knowledge and efficient easy-to-use metadata creation services hinder the sharing and reuse of research data among researchers. Due to the large amount and wide user orientation of the generalist research data repository, the metadata creation service provided by it has references for improving the above dilemmas.[Method/process] Taking six generalist research data repositories recommended by Springer Nature and Scientific Data as samples, this paper investigated and analyzed their metadata creation services from two aspects of the service content composition and the service implementation mode, then summarized their service characteristics and advanced experiences.[Result/conclusion] The metadata creation service provided by the generalist research data repository has five characteristics of following the tradition but has some innovations, striving for simplicity and highlighting its own characteristics, paying attention to the popularization of metadata knowledge and ability transformation, fully ensuring data democracy, paying attention to the organization of related resources and encouraging data reference. Its service model not only pays attention to the ease and usefulness of service but also taking account of the popularization of metadata knowledge, above which have important enlightenment and references for the research data repository construction and metadata creation service design for library and information community in China.
Subjects: Geosciences >> Other Disciplines of Geosciences submitted time 2018-11-14 Cooperative journals: 《干旱区地理》
Abstract： 为了快速有效检测南疆地区典型土壤（沙壤土）的盐分含量变化，利用光谱仪和电导仪测得南疆阿拉尔市红枣种植区盐渍土近红外高光谱和电导率数据，基于7种不同光谱预处理方法和2种特征波长选择算法，分别建立多元线性回归（MLR）和偏最小二乘回归（PLSR）的土壤盐分监测模型。结果表明，7种预处理方法中，归一化，多元散射，变量标准化和一阶导数能够有效提高土壤盐分的预测模型精度。基于多元逐步回归（SMR）波长选择方法的多元线性回归（SMLR）模型的Rval2大于0.948 9，RPD大于6.294 9，RMSEP小于0.435 6；基于连续投影算法（SPA）的多元线性回归（SPA-MLR）模型的Rval2大于0.956 8，RPD大于6.922 1，RMSEP小于0.361 6，预测结果要优于偏最小二乘回归（PLSR）模型，其中基于归一化处理后的SMLR和SPA-MLR的预测精度最为理想，分别为Rval2=0.979 2，RPD=9.907 8，RMSEP=0.287 6和Rval2=0.980 5，RPD=10.50，RMSEP=0.278 3，而且筛选的特征波长较少。说明归一化是更有效的光谱预处理方法，多元线性回归MLR更适合建立南疆典型沙壤土盐分含量的预测模型。
Subjects: Computer Science >> Integration Theory of Computer Science submitted time 2018-05-02 Cooperative journals: 《计算机应用研究》
Abstract： Association rules mining is an important research topic in data mining. Big data processing puts forward higher requirements for the efficiency of association rules mining algorithm, where the most time consuming step is frequent pattern mining. For the problem that the state of art frequent pattern mining algorithm is not efficient, a frequent pattern mining algorithm based on interval interaction and transaction mapping (IITM) is proposed, which combines Apriori algorithm and FP-growth algorithm. This algorithm just needs to scan the dataset twice to generate the FP tree, and then scan the FP tree to map the ID of each transaction to the interval. It growths the frequent pattern by interval interaction and solves the problem that the Apriori algorithm needs to scan the dataset multiple times, the FP-growth algorithm needs to iterate to generate the conditional FP tree, which reduce the efficiency of the frequent pattern mining. Experiments on real dataset show that the IITM algorithm is superior to Apriori, FP-growth, and PIETM algorithms at different support.
Subjects: Agriculture, Forestry,Livestock & Aquatic Products Science >> Other Disciplines of Agriculture, Forestry,Livestock & Aquatic Products Science submitted time 2023-02-17 Cooperative journals: 《智慧农业（中英文）》
Abstract： Irrigation schemes determined based on statistical analysis of field trials are usually only applicable to specific soils and meteorological environments. It is difficult to quantitatively analyze the impact of irrigation strategies on the growth of jujube trees. In order to realize the quantitative analysis of the influence of temperature, light and water resources on the growth of fruit trees, WOrld FOod Studies (WOFOST) model parameters were calibrated to simulate the jujube tree growth and water migration process. Firstly, the observed data obtained from field trials in 2016 and 2017 were used to calibrate the phenology development, initialization, green leaf, CO2 assimilation, dry matter partitioning, respiration, and water use parameters of the WOFOST model. Secondly, the time series of total above-ground biomass, leaf area index (LAI) and soil moisture content in field trials were dynamically simulated, and accuracy verification and analysis were also performed. Finally, the maximum LAI, yield, actual evapotranspiration (ETa ) and water use efficiency (WUE) data of 55 orchards were employed to evaluate the performance of the calibrated model at the county scale. The results showed that the coefficient of determination R2 of TAGP simulated in the field test area was between 0.92 and 0.98, and the normalized root mean square error (NRMSE) was between 8.7% and 20.5%, the R2 of simulated LAI ranged from 0.79 to 0.97, and the NRMSE ranged from 8.3% to 21.1%. The R2 of the simulated soil moisture content was between 0.29 and 0.75, and the NRMSE ranged from 4.1% and 6.1%. The model could well simulate the time series of jujube tree growth dynamics and soil moisture content changes. At the county scale, the R2 between the simulated and measured maximum LAI were 0.64 and 0.78, and the NRMSE were 13.3% and 10.7% in 2016 and 2017, respectively. The simulated yield showed R2 value of 0.48 and 0.60, and NRMSE of 12.1% and 11.9%, respectively. RMSE of the simulated versus measured ETa were 36.1 mm (7.9%) and 30.8 mm (7.4%), respectively. The model also showed high WUE simulation accuracy (10%
Subjects: Medicine, Pharmacy >> Preclinical Medicine submitted time 2017-12-07 Cooperative journals: 《分子影像学杂志》
Abstract： Objective To evaluate the high frequency color Doppler ultrasound features of thyroid microcarcinoma, and explorethe value of ultrasound in the diagnosis of thyroid microcarcinoma. Methods We retrospectively analyzed ultrasound findingsof 60 malignant nodules in 42 cases of small thyroid cancer confirmed by surgery and pathology, including the internal echo ofthe nodules, edge feature, aspect ratio, calcification size, the distribution of blood flow signal. It was compared with 48 casesbenign nodules(diameter ≤1). Results There were significant differences in terms of low internal echo, fuzzy edge, microcalcification, the aspect ratio≥1, blood flow signal distribution aspect (P<0.05). Conclusion The high frequency color Dopplerultrasound has important clinical value in the diagnosis of thyroid microcarcinoma.
Subjects: Geosciences >> Other Disciplines of Geosciences submitted time 2019-09-11 Cooperative journals: 《干旱区地理》
Abstract：通过2002—2015年的投入产出表以及投入产出延长表综合分析山西省产业发展状况，根据山西省的产业发展特征，将投入产出表中的42个行业进行了归并，运用投入产出指标对山西的产业发展状况进行了跟踪描述并采用扩散感应系数以及扩散能力系数跟踪经济发展中关键产业的变化规律，采用熵指数测算山西省的产业多元化程度，定量跟踪和评价山西产业多元化发展进程，同时运用社会网络研究方法，构建山西省投入产出关联图，直观地考察山西省的产业关联及产业发展集合。结果显示：山西省2002—2015年产业多元化进程受阻，2015年形成了两个重要的产业集合，一个是以煤炭资源业为中心，一个以建筑业为中心。
Subjects: Geosciences >> Space Physics submitted time 2016-05-13
Abstract： Numerical simulation of MHD (Magnetohydrodynamics) is an important method to study solar-terrestrial physics phenomena. In this paper, three AUSM algorithms, i.e., AUSM, AUSM+,AUSMPW+, were compared in conjunction with the HDC method to eliminate the divergence of the magnetic field. The AUSM+ algorithm is found to be better than the AUSM algorithm and the AUSMPW+ algorithm through the results of Rotor example and Orszag-Tang vortex example. Further, the AUSM+ algorithm is used to simulate the coronal with a six-component grid system. The results show that this algorithm can correctly calculate the large-scale structure of the corona. Also, the HDC method can maintain the divergence-free constraint on the magnetic field.
Peer Review Status:
Awaiting Review
Subjects: Psychology >> Social Psychology submitted time 2023-03-28 Cooperative journals: 《心理科学进展》
Abstract： In the era of the digital economy, new organizational forms such as bilateral and multilateral platforms, online communities, and ecosystems have emerged and upended mainstream theories of innovation management by calling into question fundamental assumptions and arguments. The new context also challenges the paradigm of “the individual-opportunity nexus” in entrepreneurial research. While existing research from the ecosystem perspective usually focuses on clusters at the macro-level or the meso-level, it tends to overlook micro-level actors, or small and medium-sized enterprises and their entrepreneurial activities as complementors on platforms. Meanwhile, the distribution, as well as the exploitation of entrepreneurial opportunities, have also changed due to the affordance of digital technology, leaving a gap in our knowledge on the mechanisms of opportunity creation and exploitation by new ventures that tap into resources available in the ecosystem. This study, therefore, develops the theoretical framework of “digital ecosystem characteristics-social capital-entrepreneurship opportunities” based on social capital theory as well as the affordance theory. Curious to understand how enterprises in a digital ecosystem can use ecosystem resources to accumulate social capital, this study measures the new characteristics of network behavior and relationship behavior of startups in a digital ecosystem with the three constructs of social capital, i.e., structural capital, relational capital and cognitive capital. This paper also explores the effects of social capital on the formation of opportunity beliefs of entrepreneurs under the desirability dimension of opportunities, which illustrates the startup process of how entrepreneurs transform “idea” into “action”. In addition, borrowing from the constructs of opportunity sets and opportunity portfolios from entrepreneurial research, the effects of social capital on the development of opportunity sets are also tested in the scale-up process. Finally, the moderating effects of the above paths are investigated from the cognitive monitoring of entrepreneurs and the digitization degree of new ventures. The theoretical contributions of this paper are as follows: First, this paper extends the application of social capital theory in the context of digital entrepreneurship, adding to our knowledge on entrepreneurial opportunities. Second, new characteristics of entrepreneurial opportunities in the context of digital entrepreneurship are revealed through the measurement of “opportunity belief” and “opportunity set” in the digital ecosystem. Third, the boundary conditions of“the individual-opportunity nexus” are further clarified by the matching of entrepreneurs and opportunities in the digital ecosystem.
Subjects: Management Science >> Enterprise Management submitted time 2021-12-09
Abstract： It is not clear how the nature of entrepreneurial opportunities have been changed which caused differences in formation of entrepreneurial opportunities under the background of digital entrepreneurship. Set in the context of digital ecosystem, this paper analyzes how social capital accumulated by the affordances of digital ecosystem could affect the formation and development of entrepreneurial opportunities. While opportunity is measured from both the desirability dimension and content dimension, the moderating effects of the path are also tested from the cognitive monitoring of entrepreneurs and the digitization degree of new ventures. Expanding the application of social capital theory in the context of digital entrepreneurship, this paper deepens the research of entrepreneurial opportunities in digital ecosystem, which also helps to improve the quality and efficiency of opportunity identification, and to guide "destructive creation" by entrepreneurs in digital platform, and promotes the construction of entrepreneurial ecosystem at last. "
Peer Review Status:Awaiting Review
Subjects: Computer Science >> Integration Theory of Computer Science submitted time 2018-04-24 Cooperative journals: 《计算机应用研究》
Abstract： For complex event detection in the mass real-time data from multiple sources, there is a problem of low accuracy and inefficiency in the triage of original event streams. This paper proposed a method of complex event detection based on an event tree. Firstly, defining dependencies between events, then take full account of the multi-dependencies between atomic events to generate atomic event trees and form the list with the dependent event trees, increasing the number of effective detection of complex event processing engines, such that the matching efficiency of event detection is improved. Meanwhile, this method reduces the memory consumption and improves the throughput of event detection. Simulation experiments and case studies demonstrate the advantages and feasibility of this method on massive data processing.
Subjects: Mechanics >> Applied Mechanics submitted time 2023-03-20 Cooperative journals: 《应用力学学报》
Abstract： In order to resolve the tedious problem of convolutional-differential hybrid equation solutionbased on Kanai-Tajimi spectrm of non-viscous damping structures ,a new concise closed solution methodis proposed. The non-viscous damping model usually expressed in the convolution form of an exponentialkernel function can well simulate the damping characteristics of practical engineering materials , while thecorresponding differential constitutive relationship of the damper is given in this paper. The randomground motion characteristics of the site can be better described by Kanai-Tajimi spectrum random groundmotion model , from which the structural ground motion response expression obtained in its engineering application is complex , but it can be expressed as a random process of white noise excitation by filtering e-quation.Using the differential constitutive relationship of the non-viscous damping structures and the filte-ring equation of Kanai-Tajimi spectrum, the complex ground motion excitation convolution-differential dy-namic equation is converted into a fully differential dynamic equation system excited by white noise , andthen the complex modal method and the concise characteristics of the white noise excitation are used to ob-tain the variance of the structural displacement and the concise closed solution of 0-2 order spectral mo-ment. Finally ,the dynamic reliability of the structure is analyzed based on the first exceedance failure cri-terion and Markov distribution assumptions. A comparative analysis of the method in this paper and thevirtual excitation method for a calculation example shows that the closed solution proposed in this paper iscorrect and efficient , and can be used as a verification method for the accuracy of the virtual excitationmethod.
Subjects: Geosciences >> Geography submitted time 2023-06-28 Cooperative journals: 《干旱区地理》
Abstract：文化旅游空间是当今文旅融合研究的重要方向之一。以新疆2346个POI文化旅游空间点为研究对象，通过量化统计分析，借助GIS空间分析软件中地势地貌高程分析、核密度分析、泰森多边形分析和标准差椭圆分析，图文可视化再现新疆文化旅游空间分布格局。结果表明：（1）新疆文化旅游空间分布与自然地理环境特征相适应，集中分布于河流两岸、河谷地带、山地垂直地带与沙漠边缘绿洲缓冲区，核密度高值区呈现明显的大分散-小聚集、带路性、团块状、星散状分布特征。（2）新疆文化旅游空间分布呈现北密南疏、东西相贯特征，自然旅游空间辐射影响范围较人文旅游空间广阔。（3）新疆文化旅游空间一脉相承，人文旅游空间与自然旅游空间的交往逐渐转变为文化旅游空间的资源、产品和形象，相互影响关系逐渐强化，具有显著的包容性、交融性和广阔性特征。依据上述分析结果，提出新疆文化旅游空间全域性、层次性、多样性发展研究的优化建议。
Subjects: Medicine, Pharmacy >> Clinical Medicine submitted time 2022-07-09 Cooperative journals: 《中国全科医学》
Abstract： Atrial fibrillation is one of the two cardiovascular disease bastions that need to be tackled in the 21st century. However, the traditional screening of atrial fibrillation has the limitation of "no disease at the time of detection and no detection at the time of onset". Atrial fibrillation management has disadvantages such as low detection rate, low standard management rate and so on. Wearable devices have created technical conditions for early detection and scientific management of atrial fibrillation, and their feasibility, sensitivity and specificity in atrial fibrillation screening have been gradually verified. This paper aimed to review the application status, limitation and prospect of wearable devices in atrial fibrillation screening and management.
Subjects: Statistics >> Social Statistics submitted time 2024-03-27 Cooperative journals: 《中国科学院院刊》
Abstract： In the era of digital economy, open source innovation has become the stimulator of innovation vitality, and is becoming an important source of high-quality supply of digital public goods. This study focuses on the importance of promoting the open source of state-funded scientific research projects, and summarizes the practical experience and policy measures of major countries and regions in the world on the open source of state-funded scientific research projects. It is also emphasized that the challenges of promoting the open source of state-funded scientific research projects in China. Suggestions for promoting the establishment of an open source mechanism of scientific research achievements are presented in this paper.
Subjects: Medicine, Pharmacy >> Preclinical Medicine submitted time 2017-12-27 Cooperative journals: 《南方医科大学学报》
Abstract： Objective To test the effect of CDC42 (a member of Rho family of small GTPases) knockdown mediated by a CDC42 short-hairpin RNA (shRNA) on the morphology of colorectal cancer SW480 cells in vitro. Methods Four CDC42 siRNA fragments targeting CDC42 were designed and the most efficient siRNA for CDC42 knockdown was selected to construct the shRNA vector for transfection of colorectal cancer SW480 cells. The interference efficiency in the stably transfected cells (sw480. shCDC) was detected using real-time PCR and Western blotting, and the morphological changes of the transfected cells were observed. Results Western blotting result showed that siCDC42-3 was the most efficient fragment for CDC42 knockdown, which caused CDC42 knockdown by over 50% . DNA sequencing confirmed successful construction of the CDC42 shRNA vector. Transfection of the cells with the vector significantly reduced CDC42 expressions at both the mRNA and protein levels. The transfected cells exhibited reduced filopodia and cell size with smooth cell margins. Conclusion shRNA-mediated CDC42 knockdown can reduce the cytoskeleton dynamics of colorectal cancer cells to lower their invasiveness. This shRNA construct facilitates further study of the role of CDC42 in the tumorigenesis and progression of colorectal cancer.
Subjects: Agriculture, Forestry,Livestock & Aquatic Products Science >> Soil Science submitted time 2023-05-30 Cooperative journals: 《干旱区研究》
Abstract： After ecological restoration in Horqin Sandy Land, the soil moisture dynamics of the forest and its response to rainfall affect whether Pinus sylvestris var. mongolica(PSM) can be continuously used for the ecological restoration in the same type of area. To study the characteristics of soil moisture dynamics after vegetation restoration on the southern edge of Horqin Sandy Land, this study used the methods of in situ observation and numerical simulation and corrected the HYDRUS-1D model based on the measured data of soil moisture to explore its relationship with rainfall. We obtained the following results: (1) The regional moisture distribution was changed by the PSM plantation, deep soil recharge at 2.0 m in bare sand accounted for 44.16% of the annual rainfall, whereas deep soil recharge at 2.0 m in PSM land accounted for only 0.7% of the annual rainfall. (2) Soil moisture below a depth of 0.4 m had no response to light rain, but the response depth of soil moisture to moderate rain could reach 1.0 m. The response depth to heavy rain and rainstorm involved the entire observation profile. With increasing soil depth, a decreasing trend was observed in the variation in moisture fluctuation. (3) There was a strong correlation between rainfall and volumetric soil water content at shallow depth, and the cumulative rainfall at weekly and semi- monthly intervals was significantly correlated with the volumetric soil water content of each layer(P<0.05). Rainfall >50 mm can ensure the supply of soil moisture within 2.0 m. (4) The determination coefficient of the model was between 0.61 and 0.85, and the root mean square error ranged from 0.0061 to 0.0096 cm -3·cm -3. The accuracy of the deep layer simulation was higher than that of the shallow layer. These results have important implications for rain- fed vegetation afforestation in the Horqin Sandy Land.
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