检索结果-南通市图书馆

在线全文

学校读者我要写书评

暂无评论

毫米波单用户多天线系统的混合预编码设计

电子与信息学报 2022年第2期44卷 620-626页

作者：刘文龙黄雯静王本巍金明录大连理工大学信息与通信工程学院大连116024

在毫米波MIMO通信系统中,针对如何提升频谱效率的问题,该文提出一种有效的混合预编码双层交替迭代算法。外层交替使用分解的方法解耦收发端,减少1次计算中所求变量的个数;而内层交替只对接收或者发送端进行,利用模拟域矩阵按列分解,数... 详细信息

在毫米波MIMO通信系统中,针对如何提升频谱效率的问题,该文提出一种有效的混合预编码双层交替迭代算法。外层交替使用分解的方法解耦收发端,减少1次计算中所求变量的个数;而内层交替只对接收或者发送端进行,利用模拟域矩阵按列分解,数字域矩阵按行分解,将频谱效率表达式化简为一系列子问题。考虑到模拟域矩阵中单个元素对函数的影响和模为1的限制,对列元素采取逐个优化的方案,并对每一次的解加上约束,使解始终处在收敛域内。实验结果表明,所提交替优化解决方案可以获得更好的性能且有着较低的复杂度。

关键词：多输入多输出系统毫米波混合预编码双层交替迭代算法

重组腺病毒介导的缺氧诱导因子-1α对脑缺氧后神经元中缺氧诱导因子-1α的调控

在线全文

学校读者我要写书评

暂无评论

中华老年医学杂志 2023年第8期42卷 970-973页

作者：邹哲华陶陶晋明璐徐坚秦皇岛市第一医院全科医疗科秦皇岛066000 贵州省人民医院康复医学科贵阳550004 重庆两江新区中医院神经内科重庆440020 贵州医科大学附属医院神经内科贵阳550004

目的探讨重组腺病毒介导的缺氧诱导因子-1α(HIF-1α)转染对缺氧后的大鼠大脑皮层神经元中HIF-1α的调控作用及可能机制。方法(1)制备大鼠大脑皮层神经元原代培养模型及缺氧模型。重组腺病毒缺氧诱导因子-1α(AdHIF-1α)转染和重组腺病... 详细信息

目的探讨重组腺病毒介导的缺氧诱导因子-1α(HIF-1α)转染对缺氧后的大鼠大脑皮层神经元中HIF-1α的调控作用及可能机制。方法(1)制备大鼠大脑皮层神经元原代培养模型及缺氧模型。重组腺病毒缺氧诱导因子-1α(AdHIF-1α)转染和重组腺病毒空载体(Ad)转染正常及缺氧细胞;将其分为正常对照组(Normal)、缺氧组(Hypoxia)、AdHIF-1α基因转染组、Ad组。(2)荧光显微镜下观察AdHIF-1α/Ad转染情况;采用蛋白印迹(Westernblot)法分别在12h、24h、48h及72 h观察各实验组HIF-1α蛋白的表达。结果用Ad/AdHIF-lα转染缺氧的神经元后,在荧光显微镜下观察转染48h时荧光表达最明显。Westernblot检测经AdHIF-1α基因转染组各时间点HIF-1α的表达明显增加,12h有阳性表达,24h表达有所增加,48h达高峰,持续到72h开始下降,与缺氧组相比差异均有统计学意义(P<0.01,P<0.05),Ad组与缺氧组相比无统计学意义。结论重组腺病毒介导的HIF-1α基因转染能明显提高缺氧神经元中HIF-1α的表达量,有可能对缺氧后的神经元发挥保护作用。

关键词：腺病毒科感染缺氧诱导因子1,α亚基年缺氧,脑

Shor's algorithm does not factor large integers in the presence of noise

在线全文

学校读者我要写书评

暂无评论

Science China(Information Sciences) 2024年第7期67卷 305-320页

作者： jin-Yi CAI College of Letters and Science University of Wisconsin

We consider Shor's quantum factoring algorithm in the setting of noisy quantum gates. Under a generic model of random noise for(controlled) rotation gates, we prove that the algorithm does not factor integers of the form pq when the noise exceeds a vanishingly small level in terms of n—the number of bits of the integer to be factored, where p and q are from a well-defined set of primes of positive density. We further prove that with probability 1-o(1) over random prime pairs(p, q), Shor's factoring algorithm does not factor numbers of the form pq, with the same level of random noise present.

关键词： random noise Shor's algorithm rotation gates quantum computing prime factorization

Semi-analytical Solutions for Wellbores with Graded Skin Zones in Poroelastic Media

在线全文

同方期刊数据库

学校读者我要写书评

暂无评论

Acta Mechanica Solida Sinica 2024年第3期37卷 385-395页

作者： Zhiqiang Fan Zhihe jin School of Mechanics Civil Engineering and ArchitectureNorthwestern Polytechnical UniversityXi’an710072China Department of Mechanical Engineering University of MaineOronoME04469USA

In analyzing the complex interaction between the wellbore and the reservoir formation,the hydromechanical properties of the region proximal to the wellbore,referred to as the“wellbore skin zone”,play a pivotal role in determining flow dynamics and the resulting formation *** models of the wellbore skin zone generally assume a constant permeability throughout,resulting in a sharp permeability discontinuity at the skin-reservoir *** paper introduces a model for a wellbore with a continuously graded skin zone of finite thickness within a poroelastic *** solutions are derived using the Laplace transform method,addressing both positive and negative skin *** results are presented to illustrate the effects of graded permeability/skin zone thickness on pore pressures and stresses around a *** results highlight a distinct divergence in stress and pore pressure fields when comparing wellbores with negative skin zones to those with positive skin zones or no skin at all.

关键词： Poroelastic Graded permeability Analytical solution Wellbore Skin zone

Advanced Algorithm for Parameters Estimation of Negative Binomial Distribution with High Dimensional Sparse Group Structure

维普期刊数据库评论

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

Journal of Systems Science & Complexity 2024年第5期37卷 2173-2195页

作者： LI Meiqi jin Baisuo School of Management University of Science and Technology of China

Negative binomial regression is a powerful technique for modeling count data, particularly when dealing with overdispersion. However, estimating the parameters for large-dimensional sparse models is challenging due to the complexity of optimizing the mean and dispersion parameter of the negative binomial distribution. To address this issue, the authors propose a novel approach that employs two iterations of the majorize-minimize(MM) algorithm, one for estimating the dispersion parameter and the other for estimating the mean parameters. These approaches improve the convergence speed and stability of the algorithm. The authors also use group penalty for variable selection, which enhances the accuracy and efficiency of the algorithm. The proposed method provides an explicit solution,simplifies the iteration process, and maintains good stability while ensuring algorithm ***, the authors apply the proposed algorithm to the zero-inflated model and demonstrate its promising predictive performance on specific data sets. The research has important implications for count data modeling and analysis in various fields, such as data mining, machine learning, and bioinformatics.

关键词： Group structure majorize-minimize (MM) negative binomial

From 'glass basins' to 'glass barriers'

在线全文

同方期刊数据库

学校读者我要写书评

暂无评论

National Science Review 2024年第6期11卷 95-96页

作者： Yuliang jin Institute of Theoretical Physics Chinese Academy of Sciences School of Physical Sciences University of Chinese Academy of Sciences Center for Theoretical Interdisciplinary Sciences Wenzhou InstituteUniversity of Chinese Academy of Sciences

If a supercooled liquid is cooled rapidly to avoid crystallization, a glass is *** this procedure, the viscosity can increase by more than 10 orders of magnitude over a small temperature range near the glass transitio... 详细信息

关键词： LIQUIDS

Combined Treatment with Bojungikgi-tang(Buzhong Yiqi Decoction)and Riluzole Attenuates Cell Death in TDP-43-Expressing Cells

在线全文

同方期刊数据库

学校读者我要写书评

暂无评论

Chinese Journal of Integrative Medicine 2024年第7期30卷 616-622页

作者： Eun jin Yang Department of KM Science Research Korea Institute of Oriental MedicineDaejeonYuseong-gu34054Republic of Korea

Objective To examine the effect of combined treatment with Bojungikgi-tang(BJIGT,Buzhong Yiqi Decoction)and riluzole(RZ)in transactive response DNA-binding protein 43(TDP-43)stress granule(SG)cells,a amyotrophic lateral sclerosis(ALS)cell line using transcriptomic and molecular *** TDP-43 SG cells were pretreated with BJIGT(100µg/mL),RZ(50µmol/L),and combined BJIGT(100µg/mL)/RZ(50µmol/L)for 6 h before treatment with lipopolysaccharide(LPS,200µmol/L).Cell viability assay was performed to elucidate cell toxicity in TDP-43 SC cells using a cell-counting kit-8(CCK8)assay *** expression levels of cell death-related proteins,including Bax,caspase 1,cleaved caspase 3 and DJ1 in TDP-43 SG cells were examined by Western blot *** autophagy-related proteins,including pmTOR/mTOR,LC3b,P62,ATG7 and Bcl-2-associated athanogene 3(Bag3)were investigated using immunofluorescence and immunoblotting *** Cell viability assay and Western blot analysis showed that combined treatment with BJIGT and RZ suppressed LPS-induced cell death and expression of cell death-related proteins,including Bax,caspase 1,and DJ1(P<0.05 or P<0.01).Immunofluorescence and immunoblotting assays showed that combined treatment with BJIGT and RZ reduced LPS-induced formation of TDP-43 aggregates and regulated autophagy-related protein levels,including p62,light chain 3b,Bag3,and ATG7,in TDP-43-expressing cells(P<0.05 or P<0.01).Conclusion The combined treatment of BJIGT and RZ might reduce inflammation and regulate autophagy dysfunction in TDP-43-induced ALS.

关键词： Bojungikgi-tang Buzhong Yiqi Decoction transactive response DNA-binding protein 43 autophagy oxidative stress amyotrophic lateral sclerosis

在线全文

学校读者我要写书评

暂无评论

空间调制系统的星座优化设计

系统工程与电子技术 2019年第5期41卷 1156-1161页

作者：斯琴图雅刘文龙赵冠男金明录兪相朝大连理工大学信息与通信工程学院辽宁大连116024 辽宁师范大学物理与电子技术学院辽宁大连116029 仁荷大学信息与通信工程学院韩国仁川22212

作为一种新颖的多天线技术,空间调制(spatial modulation,SM)受到了学者的关注。近年来,SM系统的星座设计成为研究热点。然而现有的星座设计算法由于预先设定星座结构,导致不能得到最优的星座图。对此,在发送功率受限的条件下提出一种... 详细信息

作为一种新颖的多天线技术,空间调制(spatial modulation,SM)受到了学者的关注。近年来,SM系统的星座设计成为研究热点。然而现有的星座设计算法由于预先设定星座结构,导致不能得到最优的星座图。对此,在发送功率受限的条件下提出一种新的星座设计方案。该方案基于最小化SM系统误符号率(symbol error rate,SER)准则,通过扩大可行域范围并利用遗传算法,对SM系统的信号星座进行了优化。此外,深入分析了信号星座对SER及系统参数对星座设计的影响。仿真结果表明,该算法得到的星座图相比于其他星座图具有更好的SER性能。

关键词：空间调制星座设计遗传算法

Mobility of rhenium and selenium during chemical weathering and their implication for petrogenic organic carbon oxidation

在线全文

学校读者我要写书评

暂无评论

Science China Earth Sciences 2024年第3期67卷 740-750页

作者： Yuhong ZHANG jin WANG Yuanxin QU Chao ZHU Zhangdong jin State Key Laboratory of Loess and Quaternary Geology Institute of Earth EnvironmentChinese Academy of SciencesXi'an 710061China University of Chinese Academy of Sciences Beijing 100049China Xi'an Institute for Innovative Earth Environment Research Xi'an 710061China Institute of Global Environmental Change Xi'an Jiaotong UniversityXi'an 710049China

The oxidative weathering of petrogenic organic carbon(OC_(petro)) is an important source of carbon dioxide(CO_(2)) into the atmosphere on geological timescales and significantly influences the carbon cycle and global climate change. However, at present, a robust proxy to assess OC_(petro)oxidation is lacking. Riverine rhenium(Re) has emerged as a potential proxy to trace OC_(petro)oxidation, but little is known about Re sources and its relationship with OC_(petro)oxidation. To better understand the robustness of this proxy, we analyzed a shale weathering profile from the early Cambrian Shuijingtuo Formation in Chengkou County, Chongqing City, to address the mobility of Re and selenium(Se) and their relationship with the oxidation of OC_(petro)by analyses of the elemental variation and sequential extraction. The results showed that the chemical index of alteration(CIA)increases from the fresh bedrock to the weathered sections, indicating enhanced weathering intensity. Based on the sequential extraction and mass transfer coefficients(τ), Re and Se mainly exist in the organic phase of shale and are paired lost with OC_(petro) during weathering, with no obvious correlation with sulfide minerals. Furthermore, the different proportions of Re and Se loss with OC_(petro) loss can be attributed to their different geochemical behaviors during weathering. Our study supports Re as a robust proxy to trace OC_(petro) oxidation, whereas Se is the potential one. In the future, combined studies on various sedimentary rock profiles with catchment basins are needed to determine the sources of riverine Re and Se and their relationships with OC_(petro) oxidation.

关键词： Rhenium and selenium Shale Mobility OC_(petro) Chemical weathering