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An underwater acoustic direct sequence spread spectrum communication system using dual spread spectrum code

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Frontiers of Information Technology & Electronic Engineering 2018年第8期19卷 972-983页

作者： Lan-jun LIU Jian-fen LI Lin ZHOU Peng ZHAI Hao zhao jiu-cai JIN Zhi-chao LV College of Engineering Ocean University of China The First Institute of Oceanography State Oceanic Administration College of Underwater Acoustic Engineering Harbin Engineering University

With the goal of achieving high stability and reliability to support underwater point-to-point communications and code division multiple access(CDMA) based underwater networks, a direct sequence spread spectrum based underwater acoustic communication system using dual spread spectrum code is proposed. To solve the contradictions between the information data rate and the accuracy of Doppler estimation, channel estimation, and frame synchronization, a data frame structure based on dual spread spectrum code is designed. A long spread spectrum code is used as the training sequence, which can be used for data frame detection and synchronization, Doppler estimation, and channel estimation. A short spread spectrum code is used to modulate the effective information data. A delay cross-correlation algorithm is used for Doppler estimation, and a correlation algorithm is used for channel estimation. For underwater networking, each user is assigned a different pair of spread spectrum codes. Simulation results show that the system has a good anti-multipath, anti-interference, and anti-Doppler performance, the bit error rate can be smaller than 10^(-6) when the signal-to-noise ratio is larger than-10 dB, the data rate can be as high as 355 bits/s, and the system can be used in the downlink of CDMA based networks.

关键词： Underwater acoustic communication Direct sequence spread spectrum Doppler estimation and compensation Channel estimation and equalization Gold code Single carrier Code division multiple access

铸态GH4169高温合金的热变形行为及显微硬度变化

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塑性工程学报 2024年第10期31卷 176-183页

作者：赵志伟李九霄董安平王旭彤王迪范敏灏李子怿上海工程技术大学材料科学与工程学院上海201620 上海交通大学金属基复合材料国家重点实验室上海200240

采用Gleeble-3500热模拟试验机对铸态GH4169镍基高温合金在不同变形温度(900~1150℃)、不同应变速率(0.001~1s^(-1))及压缩量为50%的条件下进行了热压缩实验。研究了GH4169镍基高温合金在不同变形条件下的真应力-真应变曲线,利用Arrhen... 详细信息

采用Gleeble-3500热模拟试验机对铸态GH4169镍基高温合金在不同变形温度(900~1150℃)、不同应变速率(0.001~1s^(-1))及压缩量为50%的条件下进行了热压缩实验。研究了GH4169镍基高温合金在不同变形条件下的真应力-真应变曲线,利用Arrhenius双曲正弦函数结合Z参数,构建了合金热变形的本构关系并探讨了加工硬化行为,最后对其显微硬度进行了测试。结果表明,该合金的流变应力随变形温度升高而降低,但随应变速率升高而升高。所建立的本构方程可以较好地描述该合金热变形过程中的行为。随应变速率下降或变形温度的增加,合金的显微维氏硬度整体表现为下降的趋势。再结晶晶粒细化导致相应的显微维氏硬度增加。

关键词： GH4169高温合金热变形本构方程加工硬化显微硬度

Straw and biochar strongly affect functional diversity of microbial metabolism in paddy soils

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Journal of Integrative Agriculture 2019年第7期18卷 1474-1485页

作者： YUAN Hong-zhao ZHU Zhen-ke WEI Xiao-meng LIU Shou-long PENG Pei-qin Anna Gunina SHEN Jian-lin Yakov Kuzyakov GE Ti-da WU Jin-shui WANG jiu-rong Key Laboratory of Agro-ecological Processes in Subtropical Region/Changsha Research Station for Agricultural and Environmental Monitoring Institute of Subtropical AgricultureChinese Academy of SciencesChangsha 410125P.R.China College of Environmental Science and Engineering Central South University of Forestry and TechnologyChangsha 410004P.R. China Department of Soil Biology and Biochemistry Dokuchaev Soil Science InstituteMoscow 119017Russian Federation Department of Agricultural Soil Science University of GottingenGottingen 37077Germany Institute of Environmental Sciences Kazan Federal UniversityKazan 420049Russian Federation Agro-Technology Institute RUDN UniversityMoscow 117198Russian Federation

The application of straw and biochar is widely practiced for the improvement of soil ***,its impact on microbial functional profiles,particularly with regard to paddy soils,is not well *** aim of this study was to investigate the diversity of microbial carbon use patterns in paddy soils amended with straw or straw-derived biochar in a 3-year field experiment in fallow soil and at various development stages of a rice crop(i.e.,tillering and blooming).We applied the community level physiological profiling approach,with 15 substrates(sugars,carboxylic and amino acids,and phenolic acid).In general,straw application resulted in the greatest microbial functional diversity owing to the greater number of available C sources than in control or biochar *** amendment promoted the use of α-ketoglutaric acid,the mineralization of which was higher than that of any other *** component analyses indicated that microbial functional diversity in the biochar-amended soil was separated from those of the straw-amended and control *** analyses revealed that soil organic carbon content was the most important factor regulating the pattern of microbial carbon *** and nutrient uptake by rice plants modulated microbial functions in paddy soils and stimulated the microbial use of N-rich substances,such as amino ***,our results demonstrated that the functional diversity of microorganisms in organic amended paddy soils is affected by both physicochemical properties of amendment and plant growth stage.

关键词： carbon metabolism microbial functional diversity biochar amendment paddy soil MicroRespTM

A Possible Form of NNS Distribution for Degenerate Spectra

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Chinese Journal of Chemical Physics 2006年第4期19卷 305-310页

作者： Chang-ming Xiao Nan-rong zhao jiu-li Luo Department of Physics Hunan Normal University Changsha 410081 China Institute of Chemical Physics Faculty of Chemistry Sichuan University Chengdu 510054 China

To expose the statistical properties of the degenerated spectrum, with the aid of the random matrix theory, a possible form of the NNS distribution function of the degenerate spectrum was proposed by providing a solution in terms of the same-degeneracy case. The results indicate that the target spectrum is transformed into two sub-spectra： a random one and a regular one, and that the repulsion level of the regular spectrum is also decreased.

关键词： NNS distribution Degenerate spectum Random matrix theory

糯玉米子粒硬度与淀粉合成相关酶动态变化及相互关系

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玉米科学 2024年第6期32卷 38-45页

作者：史亚兴董会刘辉徐丽樊艳丽俞嫒年史亚民卢柏山赵久然北京市农林科学院玉米研究所/玉米DNA指纹及分子育种北京市重点实验室北京100097

以鲜食糯玉米品种京科糯2000和苏玉糯2号为试验材料,比较授粉后不同时期淀粉合成相关酶活性、淀粉含量、含水量和子粒硬度的差异及各指标间的相互关系,利用Logistic方程比较两个品种子粒淀粉积累速率。结果表明,糯玉米子粒淀粉合成相关... 详细信息

以鲜食糯玉米品种京科糯2000和苏玉糯2号为试验材料,比较授粉后不同时期淀粉合成相关酶活性、淀粉含量、含水量和子粒硬度的差异及各指标间的相互关系,利用Logistic方程比较两个品种子粒淀粉积累速率。结果表明,糯玉米子粒淀粉合成相关酶AGPase活性和SSS活性对淀粉的合成具有重要的促进作用,且在品种间有差异。利用Logistic方程比较两个品种糯玉米子粒淀粉积累过程,分析表明,与苏玉糯2号相比,京科糯2000达到最大淀粉积累速率的天数(T_(max))延长1.62 d,淀粉活跃积累天数增加8.85 d,子粒淀粉积累速率最大时的生长量(W_(max))提高3.97%,最大淀粉积累速率(G_(max))降低12.60%。糯玉米子粒淀粉含量与子粒含水量呈极显著负相关,与子粒硬度呈极显著正相关。

关键词：糯玉米淀粉积累子粒含水量硬度

Graphdiyne oxide doping for aggregation control of hole-transportnanolayer in inverted perovskite solar cells

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Nano Research 2022年第11期15卷 9734-9740页

作者： Xu Cai Jin Tang Min zhao Le Liu Zhibin Yu Jiajia Du Ling Bai Fushen Lu Tonggang jiu Yuliang Li Science Center for Material Creation and Energy Conversion Institute of Frontier and Interdisciplinary Science&School of Chemistry and Chemical EngineeringShandong UniversityQingdao 266237China Department of Chemistry and Key Laboratory for Preparation and Application of Ordered Structural Materials of Guangdong Province Shantou UniversityShantou 515063China Beijing National Laboratory for Molecular Sciences(BNLMS) Institute of ChemistryChinese Academy of SciencesBeijing 100190China

The strong aggregation tendency of hole transport material poly[3-(4-carboxylbutyl)thiophene-K(P3CT-K)restricts its further application in inverted perovskite solar cells(PSCs).Here,we report an effective strategy to address this issue and achieve the superior performance of inverted methylammonium lead triiodide(MAPbI3)PSCs,in which graphdiyne oxide(GDYO)doped P3CT-K nanocomposites are applied as the hole transport nanolayer(HTL).It is revealed that the strongπ–πstacking interaction occurs between GDYO and P3CT-K,which is proved by the blue shift of the absorption peak of P3CT-K *** aggregation control via GDYO contributes to the property improvement of P3CT-K ***,the homogeneous coverage induces the growth of perovskite grain with larger size than that based on the undoped *** a result,the optimized surface morphology,enhanced conductivity,charge extraction as well as better crystal quality,finally improve the device *** optimal power conversion efficiency of 19.06%is achieved,with simultaneously improved fill factor and short circuit current *** work presents the potential of functional graphdiyne(GDY)in the development of highly efficient photovoltaic device.

关键词： graphdiyne oxide perovskite solar cells hole transport layer aggregation control carriers transfer

维普期刊数据库评论

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基于资源感知的多域服务功能链编排成本优化

计算机系统应用 2024年第5期33卷 178-186页

作者：徐九韵脱颖超赵耀鹏李世宝中国石油大学(华东)计算机科学与技术学院青岛266580 中国石油大学(华东)海洋与空间信息学院青岛266580

网络功能虚拟化技术的兴起使得实例化为服务功能链(SFC)的网络服务能够共享基底网络,缓解了传统网络体系结构僵化的问题.然而,网络中大量服务请求给多域SFC编排带来了新的挑战.首先由于域内网络资源信息及内部策略的保密性,使得多域SFC... 详细信息

网络功能虚拟化技术的兴起使得实例化为服务功能链(SFC)的网络服务能够共享基底网络,缓解了传统网络体系结构僵化的问题.然而,网络中大量服务请求给多域SFC编排带来了新的挑战.首先由于域内网络资源信息及内部策略的保密性,使得多域SFC的编排更为复杂.其次多域SFC编排要确定最佳候选编排域集,先前的研究较少考虑域间负载的均衡性,对服务接受率造成了消极影响.此外跨网络域编排服务请求对服务的成本和响应时间提出了更严格的要求.为解决上述挑战,在本文中,我们首先针对多域网络隐私性需求,提出了域级图的构造方法;然后基于域间负载均衡提出了域权重的计算方法进行SFC编排域的选择;最后,针对多域网络成本和响应时间需求,提出编排算法.实验结果表明,提出的算法有效地权衡了平均服务成本和接受率,并且在服务平均响应时间方面也得到了优化.

关键词：网络功能虚拟化多域网络服务功能链编排资源感知编排成本优化

基于MaxEnt模型的祁连山南麓门源草原毛虫分布区预测

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昆虫学报 2024年第6期67卷 827-838页

作者：刘玉英严林于红妍牟丹赵啟军林扎西尖措高太侦谢久祥青海大学农牧学院西宁810016 祁连山国家公园青海服务保障中心西宁810000 天峻县林业和草原站天峻817200

【目的】门源草原毛虫Gynaephora menyuanensis是为害青藏高原高寒草甸的主要害虫,严重妨碍草地生态和畜牧业发展,了解其在祁连山南麓的实际分布区和潜在适生区对门源草原毛虫的监测和防治以及草地生态的保护具有重要意义。【方法】本... 详细信息

【目的】门源草原毛虫Gynaephora menyuanensis是为害青藏高原高寒草甸的主要害虫,严重妨碍草地生态和畜牧业发展,了解其在祁连山南麓的实际分布区和潜在适生区对门源草原毛虫的监测和防治以及草地生态的保护具有重要意义。【方法】本研究在对祁连山南麓门源草原毛虫的分布进行大量实地调查(147个位点)的基础上,采用专业统计分析软件IBM SPSS 22.0筛选影响门源草原毛虫分布的环境因子,应用生态位模型MaxEnt 3.4.4和地理信息系统软件ArcGIS 10.8预测祁连山南麓门源草原毛虫2021-2040年的适生区范围。【结果】影响门源草原毛虫分布的主要环境因子为9月平均降水量、 9月平均太阳辐射等;2021-2040年门源草原毛虫在祁连山南麓的适生区变化趋势为高适生区和非适生区的面积呈减少趋势,中适生区和低适生区面积呈增加趋势;检测模型的受试者工作特征(receiver operating characteristic, ROC)曲线下的面积(area under ROC, AUC)值为0.924,模拟结果准确性较好。【结论】本研究结果为阐明门源草原毛虫的地理分布规律及其监测防治提供了理论参考。全球气候变化为门源草原毛虫的栖息地扩张提供了适宜的条件,建议根据门源草原毛虫的潜在适生等级,构建“分级应对”的监测和早期预警体系与防控模式,以应对害虫为害。

关键词：门源草原毛虫青藏高原草地保护草地害虫潜在分布区分布规律

Disposal of Waste Plastics With Traditional Coking Process

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Journal of Iron and Steel Research International 2006年第1期13卷 5-9页

作者： CAI jiu-ju YU Guang-wei LIAO Hon-qiang QIAN Kai zhao Pen HE Ya-bin State Key Laboratory of Bioindustry Northeastern University Shenyang 110004 Liaoning China Shougang Technical Research Institute Shougang Group Beijing 100041 China

A new technology for treating waste plastics （WP） by traditional coking process was introduced. With a thermo-balance and a 10 g atmospheric fixed bed reactor, the thermo-gravimetric behavior and product were studied during co-coking of WP with blended coal. And then, using a coke-oven with capacity of 200 kg, the characteristics of products were assessed. The results showed that there is an overlapping temperature range （200-550℃ ） of decomposition between WP and blended coal, and the pyrolysis synergism index η and synergism strength β proposed could evaluate the synergism between them. 1% of added WP results in the maximum synergism in all series experiments. The increase of added WP decreases the synergism. Tar yield in co-coking is increased with the decrease of water yield for synergism. Moreover, it was also found that the quality indexes of coke, such as M10, M40, CRI and CSR, are degraded with the increase of WP until 4%, though the quality of tar and gas is optimized for WP addition.

关键词： waste plastics coal coking