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Joint optimization of user association and resource allocation in cache-enabled terrestrial-satellite integrating network

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Science China(Information Sciences) 2021年第8期64卷 90-103页

作者： Shuang NI Junyu LIU Min SHENG Jiandong LI xiaona zhao State Key Laboratory of Integrated Service Networks Xidian University

Although low earth orbit(LEO) satellites can provide high-capacity backhaul to serve the terrestrial network, the performance of terrestrial-satellite communication systems is critically influenced by the coupling of user association and resource allocation in this integrating system, where user association includes small-cell base station(SBS)-user association and SBS-satellite association. In this work, we consider a cache-enabled terrestrial-satellite integrating network, in which LEO satellites provide backhaul for cacheenabled SBSs to serve ground users. Targeting at maximizing the downlink sum rate of the system and the number of accessed ground users, we formulate an optimization problem where user association and resource allocation of both terrestrial and satellite networks are joint optimized. Owing to the coupling relationship and integer programming nature of this optimization problem, we use Lagrangian relaxation to decouple and decompose it into two subproblems. We propose a user-division matching(UDM) algorithm by dividing all users into multiple user groups, which skillfully solves the first subproblem with multi-objectives. Afterward,to depict the nature of multi-connectivity sufficiently, the second subproblem is converted into a many-toone matching game and solved by a modified Gale-Shapely(MGS) algorithm, which is highly efficient for different satellite constellations. Simulation results demonstrate the proposed algorithms can significantly improve the downlink sum rate of the system by 28.5–120.7 compared to the benchmark algorithms in the typical settings and balance the tradeoff between the downlink sum rate of the system and the number of accessed ground users. Moreover, it also shows that <1% system performance loss can be obtained by the proposed method compared to the optimal solution.

关键词： terrestrial-satellite integrating network content caching user association resource allocation satellite backhaul

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氮肥对饲用小黑麦生产性能及营养品质的影响

西北农林科技大学学报（自然科学版） 2024年第8期52卷 27-35页

作者：明雪花王斌王腾飞马霞张译尹赵小娜兰剑宁夏大学林草学院宁夏银川750021 宁夏草牧业工程技术研究中心宁夏银川750021

【目的】研究氮肥对饲用小黑麦生产性能和营养品质的影响,确定宁夏雨养区饲用小黑麦的最佳氮肥施用量,为饲用小黑麦的高效生产和可持续发展提供参考。【方法】2021-2022年,以‘晋饲草1号’饲用小黑麦为试验材料,在宁夏固原市原州区曹堡... 详细信息

【目的】研究氮肥对饲用小黑麦生产性能和营养品质的影响,确定宁夏雨养区饲用小黑麦的最佳氮肥施用量,为饲用小黑麦的高效生产和可持续发展提供参考。【方法】2021-2022年,以‘晋饲草1号’饲用小黑麦为试验材料,在宁夏固原市原州区曹堡村进行大田试验,研究氮肥不同施用量(0 kg/hm ^(2)(F_(1),对照),75 kg/hm ^(2)(F_(2)),150 kg/hm ^(2)(F_(3))和225 kg/hm ^(2)(F_(4)))对饲用小黑麦生产性能和氮肥偏生产力以及营养品质的影响,并分析生产性能与营养品质间的相关性,最后采用主成分分析法对不同氮肥处理饲用小黑麦的农艺性状和营养品质进行综合评价。【结果】2021-2022年,施氮肥处理的饲用小黑麦株高、叶茎比、叶片数和叶面积均高于未施氮肥处理,其中F_(3)处理的上述所有指标均最高。2021年和2022年,随着氮肥施用量的增加,饲用小黑麦粗灰分含量呈先降低后升高的趋势,粗脂肪、中性洗涤纤维和酸性洗涤纤维含量均呈降低趋势,粗蛋白含量和相对饲喂价值均呈先增加后降低的趋势,其中F_(3)处理的中性洗涤纤维和酸性洗涤纤维含量均较低,粗蛋白含量和相对饲喂价值均最高。2021年和2022年,随着氮肥施用量的增加,饲用小黑麦干草产量和粗蛋白产量均呈先增加后降低的趋势,饲用小黑麦氮肥偏生产力呈降低趋势,其中F_(3)处理饲用小黑麦的干草产量和粗蛋白产量均显著高于其他处理。相关性分析结果显示,饲用小黑麦的干草产量与株高、叶片数、粗蛋白产量以及粗蛋白含量呈显著正相关(PF_(2)>F_(4)>F_(1)。【结论】当氮肥施用量为150 kg/hm ^(2)时,饲用小黑麦生长指标、生产性能及营养品质总体均较优,为宁夏雨养区饲用小黑麦的最佳氮肥施用量。

关键词：饲用小黑麦氮施施用农艺性状营养品质氮肥偏生产力

Spectrum-Efficient User Association in Caching Enabled Dense Small Cell Network

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China Communications 2023年第3期20卷 86-104页

作者： Junyu Liu Min Sheng xiaona zhao Shuang Ni Jiandong Li State Key Laboratory of ISN Xidian UniversityXi’an 710071China Department of Broadband Communication Peng Cheng LaboratoryShenzhen 518055China

In this paper,we reveal the fundamental limitation of network densification on the performance of caching enabled small cell network(CSCN)under two typical user association rules,namely,contentand distance-based *** indicates that immoderately caching content would significantly change the interference distribution in CSCN,which may degrade the network area spectral efficiency(ASE).Meanwhile,it is shown that content-based rule outperforms the distance-based rule in terms of network ASE only when small cell base stations(BSs)are sparsely deployed with low decoding ***,it is proved that network ASE under distance-based user association serves as the upper bound of that under content-based rule in dense BS *** enable more spectrum-efficient user association in dense CSCN,we further optimize network ASE by designing a probabilistic content retrieving strategy based on distance-based *** the optimized retrieving probability,network ASE could be substantially enhanced and even increase with the growing BS density in dense BS regime.

关键词： caching dense network user association

宁夏盐碱地饲用小黑麦品种(系)生产性能及营养品质综合评价

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西北农林科技大学学报（自然科学版） 2024年第9期52卷 19-29页

作者：马霞王斌王腾飞明雪花张译尹赵小娜兰剑宁夏大学林业与草业学院宁夏银川750021 宁夏草牧业工程技术研究中心宁夏银川750021

【目的】筛选适合宁夏盐碱地种植的优质高产小黑麦(Triticosecale wittmack)品种(系)。【方法】2021年在宁夏石嘴山市惠农区开展晋饲草1号、冀饲草1号、鉴47、鉴46、优能、普瑞、冀饲3号、石大1号、中饲1048和甘农2号共10个品种(系)小... 详细信息

【目的】筛选适合宁夏盐碱地种植的优质高产小黑麦(Triticosecale wittmack)品种(系)。【方法】2021年在宁夏石嘴山市惠农区开展晋饲草1号、冀饲草1号、鉴47、鉴46、优能、普瑞、冀饲3号、石大1号、中饲1048和甘农2号共10个品种(系)小黑麦的适应性研究,并利用主成分分析(PCA)对其农艺性状、生产性能及营养成分等指标进行综合评价。【结果】所有供试饲用小黑麦品种(系)均能在宁夏盐碱地安全越冬并完成生育期。晋饲草1号株高、分蘖数和干草产量最突出,分别达131.11 cm、4.40个和9.34 t/hm 2;冀饲3号和晋饲草1号粗蛋白含量较高,分别为9.95%和9.86%;冀饲3号的相对饲喂价值最高,为94.25。聚类分析结果表明,10个饲用小黑麦品种(系)可以分为3个类群,第Ⅰ类群为普瑞和优能,第Ⅱ类群为甘农2号、中饲1048和鉴47,第Ⅲ类群为晋饲草1号、冀饲3号、冀饲草1号、鉴46和石大1号。主成分分析结果显示,综合得分排名前三的小黑麦品种(系)为冀饲3号、晋饲草1号和石大1号。【结论】冀饲3号、晋饲草1号和石大1号均可在宁夏盐碱地大面积推广种植。

关键词：饲用小黑麦生产性能营养品质聚类分析主成分分析宁夏盐碱地

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Mechanically activated starch magnetic microspheres for Cd(Ⅱ)adsorption from aqueous solution

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Chinese Journal of Chemical Engineering 2021年第5期34卷 40-49页

作者： Xinling Xie xiaona zhao Xuan Luo Tongming Su Youquan Zhang Zuzeng Qin Hongbing Ji School of Chemistry and Chemical Engineering Guangxi Key Laboratory of Petrochemical Resource Processing and Process Intensification TechnologyGuangxi UniversityNanning 530004China Fine Chemical Industry Research Institute School of ChemistrySun Yat-sen UniversityGuangzhou 510275China

Magnetic starch microspheres(AAM-MSM)were synthesized via an inverse emulsion graft copolymerization by using mechanically activated cassava starch(MS)as a crude material,acrylic acid(AA)and acrylamide(AM)as graft copolymer monomers,and methyl methacrylate(MMA)as the dispersing agent and used as an adsorbent for the removal of Cd(Ⅱ)ions from aqueous ***-transform infrared spectroscopy(FT-IR),X-ray photoelectron spectroscopy(XPS),scanning electron microscopy(SEM),and vibrating sample magnetometry(VSM)were used to characterize the AAM-MSM *** results indicated that AA,AM,and MMA were grafted to the MS,and the Fe_(3)O_(4) nanoparticles were encapsulated in the AAM-MSM adsorbent *** adsorbent exhibited a smooth surface,uniform size,and good sphericity because of the addition of the MMA and provided more adsorption sites for the Cd(Ⅱ)*** maximum adsorption capacity of Cd(Ⅱ)on the AAM-MSM was 39.98 mg·g^(-1).The adsorbents were superparamagnetic,and the saturation magnetization was 16.7 A·m^(2)·kg^(-1).Additionally,the adsorption isotherms and kinetics of the adsorption process were further *** process of Cd(Ⅱ)ions adsorbed onto the AAM-MSM could be described more favorably by the pseudo-second-order kinetic and Langmuir isothermal adsorption models,which suggested that the chemical reaction process dominated the adsorption process for the Cd(Ⅱ)and chemisorption was the rate-controlling step during the Cd(Ⅱ)removal process.

关键词： Mechanical activation Magnetic starch microspheres Cadmium ion Adsorption Separation Model

Enhancing capacitive deionization performance and cyclic stability of nitrogen-doped activated carbon by the electro-oxidation of anode materials

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Chinese Journal of Chemical Engineering 2024年第5期69卷 23-33页

作者： xiaona Liu Baohua zhao Yanyun Hu Luyue Huang Jingxiang Ma Shuqiao Xu Zhonglin Xia Xiaoying Ma Shuangchen Ma School of Environmental Science and Engineering North China Electric Power UniversityBaoding 071003China Huadian Zhengzhou Machinery Design and Research Institute Co. LtdZhengzhou 450002China Huadian Inner Mongolia Energy Co. Ltd.Baotou Power Generation BranchBaotou 014013China

Electrode materials with high desalination capacity and long-term cyclic stability are the focus of capacitive deionization(CDI) community. Understanding the causes of performance decay in traditional carbons is crucial to design a high-performance material. Based on this, here, nitrogen-doped activated carbon(NAC) was prepared by pyrolyzing the blend of activated carbon powder(ACP) and melamine for the positive electrode of asymmetric CDI. By comparing the indicators changes such as conductivity, salt adsorption capacity, pH, and charge efficiency of the symmetrical ACP-ACP device to the asymmetric ACP-NAC device under different CDI cycles, as well as the changes of the electrochemical properties of anode and cathode materials after long-term operation, the reasons for the decline of the stability of the CDI performance were revealed. It was found that the carboxyl functional groups generated by the electro-oxidation of anode carbon materials make the anode zero-charge potential(E_(pzc)) shift positively,which results in the uneven distribution of potential windows of CDI units and affects the adsorption capacity. Furthermore, by understanding the electron density on C atoms surrounding the N atoms, we attribute the increased cyclic stability to the enhanced negativity of the charge of carbon atoms adjacent to quaternary-N and pyridinic-oxide-N.

关键词： Anodic oxidation Capacitive deionization Cyclic stability N-doping

三种无创性方法早期诊断兔激素性股骨头坏死的对比研究

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中华实验外科杂志 2024年第3期41卷 614-618页

作者：王小龙赵建民赵晓娜甄志龙刘瑞张国梁李强满达郝廷内蒙古医科大学第二附属医院手足显微外科呼和浩特010010 内蒙古医科大学附属医院骨科呼和浩特010050 内蒙古妇幼保健院儿童保健科呼和浩特010020 内蒙古医科大学第二附属医院创伤骨科呼和浩特010010

目的比较磁共振成像(MRI)、^(99m)Tc-亚甲基二膦酸盐(^(99m)Tc-MDP)显像、^(99m)Tc-半胱氨酸-膜联蛋白V(^(99m)Tc-Cys-Annexin V,TP5-3)单光子发射计算机断层(SPECT)显像在激素性股骨头坏死(SIFHN)模型兔中的早期诊断价值。方法收集2022年1月至2022年12月36只新西兰大白兔,采用随机数字表法分为模型组20只、对照组16只。模型组通过注射马血清和激素建立早期动物模型,对照组注射等量生理盐水。分别于造模后的第2周、第4周分批进行MRI、^(99m)Tc-Cys-Annexin V显像及^(99m)Tc-MDP显像,影像学检查完毕行病理组织学观察验证。计量资料组间比较为t检验,计数资料组间比较为卡方检验。结果造模第2周(超早期阶段),模型组MRI和^(99m)Tc-MDP显像均未见骨坏死的异常信号,^(99m)Tc-Cys-Annexin V SPECT显像可见双侧股骨头异常放射性浓聚,其诊断价值高于MRI和^(99m)Tc-MDP显像。造模第4周(早期阶段),MRI、^(99m)Tc-MDP显像和^(99m)Tc-Cys-Annexin V SPECT显像均可检出骨坏死的异常信号,MRI检出阳性率[55.56%(5/9)]高于^(99m)Tc-MDP显像[44.44%(4/9)],而^(99m)Tc-Cys-Annexin V SPECT显像最低[33.33%(3/9)],三者比较差异无统计学意义(χ^(2)=0.90,P>0.05)。结论^(99m)Tc-Cys-Annexin V SPECT显像可在超早期检出SIFHN,但在早期仍推荐MRI检测。

关键词：激素性股骨头坏死诊断凋亡

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山西文峪河上中游森林群落多样性

生态学报 2017年第4期37卷 1093-1102页

作者：赵小娜秦浩张峰山西大学黄土高原研究所太原030006 山西大学生命科学学院太原030006

基于山西文峪河上中游森林群落的野外调查数据,选取植物生活型、生活史、固氮类型、传粉途径、种子传播途径等14个植物功能性状,计算丰富度指数(R)、多样性指数(H')、均匀度指数(E)等物种多样性指数和功能丰富度指数(FRic)、功能均匀度... 详细信息

基于山西文峪河上中游森林群落的野外调查数据,选取植物生活型、生活史、固氮类型、传粉途径、种子传播途径等14个植物功能性状,计算丰富度指数(R)、多样性指数(H')、均匀度指数(E)等物种多样性指数和功能丰富度指数(FRic)、功能均匀度指数(FEve)、功能分歧度指数(FDiv)等功能多样性指数,并用TWINSPAN对森林群落进行分类,Spearman秩相关分析多样性指数间及其与环境因子间的相关性,对山西文峪河上中游森林群落多样性进行研究。结果表明:青杄林种数最多(R=27),辽东栎油松林和油松林种数最少(R=16);白桦林的H'和E最大,油松林的H'和E最小。山杨白桦林的FRic值最大,白杄林的FRic值最小;青杄林的FEve值最大,山杨白桦林的FEve值最小;山杨林的FDiv值最大,白桦林的FDiv值最小。文峪河上中游森林群落物种多样性指数与功能多样性指数间相关性不显著(P>0.05),仅FDiv与H'呈显著负相关关系(P0.05),仅FRic与FEve呈显著负相关关系(P0.05)。

关键词：文峪河上中游森林群落物种多样性功能多样性海拔

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危险品运输中的可控风险最大流算法

河北大学学报（自然科学版） 2013年第3期33卷 225-230页

作者：毛华赵小娜河北大学数学与计算机学院河北保定071002

危险品运输中,将道路实况、天气条件、交通状况和暴露人数等因素统一为一个风险值进行考虑.综合考虑运输风险和运输量,提出危险品运输路线的优化选择方案.在实际运输中,选择路线时,运用最大风险路算法,把风险降低到可控范围内.再调用Di... 详细信息

危险品运输中,将道路实况、天气条件、交通状况和暴露人数等因素统一为一个风险值进行考虑.综合考虑运输风险和运输量,提出危险品运输路线的优化选择方案.在实际运输中,选择路线时,运用最大风险路算法,把风险降低到可控范围内.再调用Dinic算法,实现可控风险最大流的算法.实例结果表明:与经典的最小费用流的负费用圈算法相比,该算法复杂度低,占用空间小,可简化网络.

关键词：危险品运输最大风险路增量矩阵可控风险最大流