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协同OFDM放大前传空时编码系统中的功率分配

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国防科技大学学报 2012年第3期34卷 142-147页

作者：王丽洁唐艺黄勤飞魏急波国防科技大学电子科学与工程学院湖南长沙410073 中国电子系统设备工程总公司北京100141

针对由源节点和单个中继节点形成的协同正交频分复用(OFDM)Alamouti空时块码系统,分析了放大前传(AF)模式下的系统容量,给出了解析表达式。考虑节点功率独立约束的应用场景,提出了分步迭代的功率分配算法(SIPAA)来提高系统容量。该算法... 详细信息

针对由源节点和单个中继节点形成的协同正交频分复用(OFDM)Alamouti空时块码系统,分析了放大前传(AF)模式下的系统容量,给出了解析表达式。考虑节点功率独立约束的应用场景,提出了分步迭代的功率分配算法(SIPAA)来提高系统容量。该算法的核心思想是在每次迭代中,分步对源和中继节点分别进行注水功率分配,注水功率分配前对目标函数进行线性化处理,功率分配后对功率分配向量进行线性化处理以降低算法复杂度。仿真结果表明,相对于等功率分配算法,所提出的分步迭代功率分配算法可以显著提高系统容量,且仅需很少几次迭代运算就可以完成功率分配。

关键词：正交频分复用空时块码协同传输放大前传注水功率分配

不同环境态度游客对森林议题认知研究——以惠荪林场为例

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西南林业大学学报（社会科学） 2023年第4期7卷 47-52页

作者：章国锐郭德生杨宇骏黄琴扉张玮尹福建农林大学林学院福建福州350002 台湾高雄师范大学科学教育暨环境教育研究所中国台湾高雄82444

以惠荪林场为研究对象,采用two-step聚类分析法对游客进行环境态度分群,探讨不同环境态度类群的游客对森林议题的认知。结果表明:不同社会经济背景的游客环境态度有所差异,较年长、已婚且教育程度较高的游客持有较良好的环境态度;不同... 详细信息

以惠荪林场为研究对象,采用two-step聚类分析法对游客进行环境态度分群,探讨不同环境态度类群的游客对森林议题的认知。结果表明:不同社会经济背景的游客环境态度有所差异,较年长、已婚且教育程度较高的游客持有较良好的环境态度;不同环境态度认知群的游客对于森林议题的认知也有所差异,游客较为重视林地保护、森林游乐及环境教育等森林的公益性功能,对混农林业、林相改良、木材生产等经济性功能或议题重视度较弱。依据研究结果,提出了未来中国在森林经营上,要兼顾人们需求与地区森林经营目标,在提高林木产量和质量及生态保护力度的前提下,提出针对性对策,以此推进乡村振兴战略的实施,为中国生态文明建设作出贡献。

关键词：森林经营惠荪林场环境态度环境教育乡村振兴

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黄楮林保护区福建青冈年龄结构及种群动态

福建林业科技 2024年第2期51卷 91-96页

作者：邱燕连刘晨舒梁晖肖义锡黄勤飞傅书智福建省林业勘察设计院福建福州350001 福建雄江黄楮林国家级自然保护区福建闽清350800

于2023年2—6月以黄楮林保护区的福建青冈(Quercus chungii)种群为研究对象,对保护区6 hm^(2)大样地内胸径(DBH)≥5 cm的福建青冈种群进行调查,采用“空间代替时间”的方法,编制福建青冈种群的静态生命表,分析福建青冈种群变化过程。结... 详细信息

于2023年2—6月以黄楮林保护区的福建青冈(Quercus chungii)种群为研究对象,对保护区6 hm^(2)大样地内胸径(DBH)≥5 cm的福建青冈种群进行调查,采用“空间代替时间”的方法,编制福建青冈种群的静态生命表,分析福建青冈种群变化过程。结果表明,福建青冈种群中,中树个体数量最多,小树、大树、老树的个体数量较少;种群龄级结构呈“中间大,两头小”的“纺锤”形,福建青冈种群目前较为稳定,但未来可能走向衰退;福建青冈种群的死亡高峰出现在第V龄级(25 cm≤DBH≤30 cm),死亡率为0.7555。幼龄个体数量缺乏是福建青冈种群走向衰退的主要原因,建议通过野外回归技术提高幼苗数量,并加强对自然保护区的管理,以辅助福建青冈种群的扩大。

关键词：福建青冈种群年龄结构静态生命表动态分析

维普期刊数据库博看期刊

Downy feather-like para-aramid fibers and nonwovens with enhanced absorbency,air filtration and thermal insulation performances

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Nano Research 2022年第6期15卷 5695-5704页

作者： Kangli Xu Jixia Deng Guangliang Tian Lei Zhan Jiajia Ma Lijun Wang qinfei Ke Chen huang Engineering Research Center of Technical Textiles Ministry of EducationCollege of TextilesDonghua UniversityShanghai 201620China Changshu Weicheng Nonwoven Equipment Co. Ltd.Suzhou215539China

Fiber morphology with off-standing branches,as found in nature,e.g.,in goose downy feather,provides exquisite functions that can be barely achieved by man-made fiber *** this work,we develop a simple and scalable method for generating downy feather-like para-aramid fibers and *** treating commercial para-aramid microfibers with mild alkaline solution(low concentration of NaOH),a synergistic effect of chemical hydrolysis and physical shearing is successfully triggered to generate abundant nanofiber branches on the surface of para-aramid *** compared with conventional monotonous structures,nonwovens composed of downy feather-like fibers exhibit a typical multiscale fiber morphology,larger specific surface area and smaller pore size,thus showing enhanced particles adsorption capacity(over twice of the pristine nonwoven),excellent oil absorption capacity(increased by~50%),improved air filtration performances(doubled the filtration efficiency)and effective thermal insulation(thermal conductivity=26.1 mW·m^(−1)·K^(−1)).More attractively,the intrinsic flame-retardant nature of para-aramid is well inherited by the downy feather-like fibers,and the fabrication process requires neither sophisticated equipment,nor tedious procedures,making us believe the strong competitiveness of these fibers and assemblies.

关键词： downy feather-like fibers nanofibrils para-aramid nonwoven surface fibrillation oil absorption air filtration

Enhanced cellular infiltration of tissue-engineered scaffolds fabricated by PLLA nanogrooved microfibers

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Nano Research 2023年第1期16卷 1614-1625页

作者： Lei Zhan Lingtian Wang Jixia Deng Yi Zheng qinfei Ke Xinrui Yang Xing Zhang Weitao Jia Chen huang Engineering Research Center of Technical Textiles Ministry of EducationCollege of TextilesDonghua UniversityShanghai 201620China Department of Orthopedic Surgery Shanghai Jiao Tong University Affiliated Sixth People’s HospitalShanghai 200233China Department of Vascular Surgery Shanghai Ninth People’s HospitalShanghai Jiaotong University School of MedicineShanghai 200011China

Nanofibers prepared by electrospinning technique are extensively applied as building blocks for tissue-engineered scaffolds because of their high resemblance to natural extracellular matrix(ECM)and the capacity to provide more cell contacts than ***,conventional electrospun scaffolds only allow superficial growth of cells in that the size of inter-fiber pores is much smaller than the size of *** taking advantage of the positive correlation between fiber diameter and pore size in fibrous materials,we report here a simple method for fabricating poly-L-lactic acid(PLLA)microfiber scaffold with longitudinally aligned nanogrooves on fiber ***-dimensional(3D)and structurally stable PLLA scaffolds with an average pore size of 16μm were successfully acquired when the fiber diameter was 4.22μ*** topographical cues from nanogrooves ensured fast cell adhesion of scaffolds,whilst the large inter-fiber pores enabled sufficient cell ***,the nanogrooved microfiber scaffold showed improved curative effects of wound healing in a rat skin injury model,making us believe its practical significance in biomedical areas that requires fast cell adhesion and high cell infiltration.

关键词： grooved fibers electrospinning cell infiltration wound healing tissue engineering

Grooved Fibers:Preparation Principles Through Electrospinning and Potential Applications

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Advanced Fiber Materials 2022年第2期4卷 203-213页

作者： Lei Zhan Jixia Deng qinfei Ke Xiao Li Yuanming Ouyang Chen huang Xuqing Liu Yun Qian Engineering Research Center of Technical Textiles Ministry of EducationCollege of TextilesDonghua UniversityShanghai 201620China Department of Orthopedics Shanghai Jiao Tong University Afliated Sixth People’s HospitalShanghai 200233China Shanghai Engineering Research Center for Orthopaedic Material Innovation and Tissue Regeneration Shanghai 201306China College of Fisheries and Life Science Shanghai Ocean UniversityShanghai 201306China Department of Materials Science University of ManchesterOxford RdManchester M139PLUK

The surface morphology of micro-and nano-scale fber determines its application to a great *** present,a variety of secondary morphology of microfbers and nanofbers,such as porous,wrinkle,groove and so on,have been *** them,grooved micro-and nano-fbers are attracting more and more attention because of their unique morphology and *** this paper,we review the literature on grooved fbers due to void-based elongation,wrinkle-based elongation,collapsed jet-based elongation and selective *** contrast,the method of phase separation is simpler and more commonly used than selective *** is more interesting is that the number and depth of grooves on the fber surface can be well controlled by adjusting the experimental parameters,which greatly increases the research value and application felds of grooves micro-nano *** fbers can be made from a range of materials:polycaprolactone(PCL),polylactic acid(PLA),polystyrene(PS),cellulose acetate butyrate(CAB)and other *** applications of grooved micro-nano fbers are discussed in detail,including peripheral nerve regeneration,water manipulation and energy conversion.

关键词： Grooved fbers Electrospinning Morphology Mechanisms Phrase separation

Integrated transcriptome and metabolome provide insights into flavonoid biosynthesis in'P113',a new purple tea of Camellia tachangensis

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Beverage Plant Research 2023年第1期3卷 18-28页

作者： Fang Li Xinyue Deng Zheng huang Zhifei Zhao Caiyun Li qinfei Song Yingqin He Suzhen Niu Institute of Agro-bioengineering Guizhou UniversityGuiyang 550025China Tea Research Institute Chinese Academy of Agricultural SciencesHangzhou 310008China College of Architecture and Urban Planning Guizhou UniversityGuiyang 550025China The College of Humanities and Science of Guiyang Guiyang 550025China College of Tea Science Guizhou UniversityGuiyang 550025China

Plants typically exhibit the purple phenomenon as a result of an increase in flavonoids and anthocyanins.A new tea germplasm'P113'was recently selected from Camellia tachangensis,which is purple in tender *** the present study,integrated transcriptome and metabolome were used to analyze the flavonoid metabolite components and the genes involved in flavonoid biosynthesis in'P113'.A total of 86 flavonoid metabolites were identified,including 70 significantly differential metabolites(p<0.05)and they were enriched to the three metabolic pathways of ko00941,ko00942 and ko00944 through KEGG pathway analysis.A total of 136 flavonoid involved genes were obtained from transcriptomic study,of which 53 were significantly differentially expressed in developmental *** correlation between metabolite profiling and transcriptome,transcriptome and protein interactions suggested that transcription factor MYB12 and glycosyltransferase UGT78D2 had a good facilitation on purple tender *** metabolic pathways and potential genes that underlie the coloration of the shoots in'P113'are clarified in this *** also lays the groundwork for identifying potential genes involved in color variation and offers a theoretical framework for the creation and use of distinctive genetic resources and the breeding of new cultivars.

关键词： insight clarified typically

Low‑Cost,Scalable Fabrication of All‑Fabric Piezoresistive Sensors via Binder‑Free,In‑Situ Welding of Carbon Nanotubes on Bicomponent Nonwovens

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Advanced Fiber Materials 2024年第1期6卷 120-132页

作者： Guangliang Tian Yihan Shi Jixia Deng Wenhua Yu Leihang Yang Yi Lu Yi Zhao Xiangyu Jin qinfei Ke Chen huang State Key Laboratory for Modification of Chemical Fibers and Polymer Materials College of TextilesDonghua UniversityShanghai 201620China Shanghai Frontiers Science Center of Modern Textiles Donghua UniversityShanghai 201620China Department of Respiratory Medicine Shanghai Jiao Tong University Affiliated Sixth People’s HospitalShanghai 200233China Henan Key Laboratory of Medical and Protective Products Henan Yadu Industry Co.Ltd.Xinxiang 453000China

Wearable piezoresistive sensors have shown enormous application prospects in flexible electronics and human-machine ***,current piezoresistive sensors suffer from common deficiencies including high fabrication cost,poor comfort and low attachment fastness of conductive substances on substrates,thereby impeding their large-scale production and practical ***,a three-dimensional all-fabric piezoresistive sensor is reported based on coating multi-wall carbon nanotubes(MWCNTs)on bicomponent nonwovens composed of core-sheath *** combination of core-sheath fibers with a heat-induced welding strategy greatly improves the adhesion fastness and stability of MWCNT *** multi-layered all-fabric structure provides as-prepared sensors with high sensitivity(9.43%kPa^(-1)in 0-10 kPa and 0.076%kPa^(-1)in 20-120 kPa),wide pressure-sensing range(0-120 kPa),fast response/relaxation time(100 and 60 ms),good reproducibility and air *** of the sensor is demonstrated through the detection of human activities(such as pulse,cough and joint movements)and the wireless monitoring of forefinger ***,our sensor is fabricated out of cost-effective materials,using scalable approach without using glue or *** method established in this work may provide an efficient strategy for the design and production of high-performance all-fabric piezoresistive sensors.

关键词： Piezoresistive pressure sensors Core-sheath fibers All-fabric Multi-wall carbon nanotubes In-situ welding

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静电纺PAN纳米纤维膜过滤性能研究

上海纺织科技 2015年第7期43卷 59-62 65,65页

作者：施剑豪柯勤飞黄晨东华大学纺织学院上海201620

为了得到高过滤性能、低压降的纳米纤维过滤材料,研究不同质量分数的聚丙烯腈(PAN)纺丝液在不同纺丝参数下制备的纳米纤维膜,并对其形貌、结构、孔径及过滤性能进行了表征。结果表明,随着PAN质量分数的增大,静电纺丝得到的纳米纤维直径... 详细信息

为了得到高过滤性能、低压降的纳米纤维过滤材料,研究不同质量分数的聚丙烯腈(PAN)纺丝液在不同纺丝参数下制备的纳米纤维膜,并对其形貌、结构、孔径及过滤性能进行了表征。结果表明,随着PAN质量分数的增大,静电纺丝得到的纳米纤维直径增大,纤维膜平均孔径增大,过滤效率先增大后减小。随着施加电压的增大,制备的纳米纤维直径变小,纤维膜平均孔径减小,过滤效率增大。随着注射速度的增大,制备的纳米纤维直径变化不大,纤维孔径更均匀,过滤效率得到提升。研究得到最佳的静电纺丝参数为:PAN质量分数18%,施加电压18 k V,注射速度1.5 m L/h。

关键词：静电纺丝纳米纤维膜过滤性能