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两种新的push-pull平衡的大数据量无线传感器网络数据分发算法 被引量:5
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作者 陶孜谨 龚正虎 卢泽新 《计算机研究与发展》 EI CSCD 北大核心 2008年第7期1115-1125,共11页
无线传感器网络中如何获得较低的通信代价同时在事件数据的push和pull之间实现更好的平衡是各种数据分发算法共同追求的目标.分析了目前已公认较好的两种典型的有结构和无结构的数据分发算法,指出了它们的优缺点.在此基础上,结合这两种... 无线传感器网络中如何获得较低的通信代价同时在事件数据的push和pull之间实现更好的平衡是各种数据分发算法共同追求的目标.分析了目前已公认较好的两种典型的有结构和无结构的数据分发算法,指出了它们的优缺点.在此基础上,结合这两种算法使用的push-pull策略,针对不同应用环境下的无线传感器网络的ALL型查询的特定需求,提出了两种基于有结构和无结构存储模式相结合的混合型数据分发算法,分别是Hybrid-Dcs-Cn1(HDC1)算法和Hybrid-Dcs-Cn2(HDC2)算法.分析表明这两种算法在保证push-pull之间平衡的前提下解决了已有算法存在的热点问题:存储拷贝数多和查询性能低,能更好地适应传感器网络的特点,是两种能量高效的数据分发算法. 展开更多
关键词 数据分发 push-pull平衡 热点 通信代价 负载均衡 无线传感器网络
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Push-Pull型pFLASH开关单元结构设计及特性
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作者 刘国柱 洪根深 +5 位作者 于宗光 赵文彬 曹利超 吴素贞 李燕妃 李冰 《半导体技术》 CAS CSCD 北大核心 2018年第9期652-658,663,共8页
基于90 nm eFLASH工艺设计并制备了一种新型抗辐照Push-Pull型pFLASH开关单元,并对其特性进行了研究。该结构由2个2T-FLASH管(T1/T2)和1个信号传输PMOS管(T3)组成,采用带带隧穿(BTBT)编程方式和福勒-诺德海姆(FN)擦除方式实现... 基于90 nm eFLASH工艺设计并制备了一种新型抗辐照Push-Pull型pFLASH开关单元,并对其特性进行了研究。该结构由2个2T-FLASH管(T1/T2)和1个信号传输PMOS管(T3)组成,采用带带隧穿(BTBT)编程方式和福勒-诺德海姆(FN)擦除方式实现其"开/关"态功能。同时,对其"开/关"态特性进行表征,研究其耐久性和电荷保持特性,最后,对其抗总剂量(TID)能力进行评估。实验结果表明:该器件的"T1编程-T2擦除"与"T1擦除-T2编程"态均可以实现信号传输管的"开/关"态功能,其阈值窗口的均值约为10.5 V;在工作电压为-1.2 V条件下,T3管的"开"态驱动电流均值约为0.92 mA,"关"态漏电流低于40 pA,且均表现出了良好的一致性。同时,该器件的循环擦/写次数可达10 000次,在25℃的"开/关"态应力条件下寿命大于10年,抗总剂量能力可达150 krad(Si)以上。 展开更多
关键词 push-pull型pFLASH开关单元 “开/关”态 阈值窗口 电荷保持性 总剂量(TID)
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基于第三方的Push-Pull逆向物流模式
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作者 于建红 鲁耀斌 《管理学报》 2005年第z1期174-177,共4页
首先阐述了逆向物流的内涵、功能以及基于第三方逆向物流的提出,其次分析了外包逆向物流的优势,最后分析了生产控制系统中的Push-Pull方法.在此基础上,提出基于第三方的Push-Pull逆向物流模式.
关键词 逆向物流 第三方逆向物流 push-pull
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基于DTN网络的PUSH-PULL策略研究
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作者 崔永锋 《河南师范大学学报(自然科学版)》 CAS CSCD 北大核心 2010年第6期54-56,共3页
DTN网络是新一代的网络体系结构,PUSH-PULL是解决DTN网络中拥塞控制的一种有效策略,介绍了DTN网络中拥塞控制的研究现状,并对PUSH-PULL的各个策略进行了阐述,通过NS2搭建DTN网络环境并通过模拟对PUSH-PULL的7种策略进行仿真,模拟仿真结... DTN网络是新一代的网络体系结构,PUSH-PULL是解决DTN网络中拥塞控制的一种有效策略,介绍了DTN网络中拥塞控制的研究现状,并对PUSH-PULL的各个策略进行了阐述,通过NS2搭建DTN网络环境并通过模拟对PUSH-PULL的7种策略进行仿真,模拟仿真结果表明,采用PUSH-PULL策略的可以有效的提高信息的传输率. 展开更多
关键词 DTN push-pull NS2 仿真
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高并发数据共享系统基于Push-Pull混合模式的性能优化
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作者 王子光 王子明 《现代信息科技》 2018年第4期65-67,共3页
随着面向服务架构的大规模分布式系统的应用,多个系统之间由于数据集成的需要,彼此间要高并发传递大量数据,特别是状态数据的同步,对数据的实时性要求越来越高。数据单纯通过客户端以Pull(拉取)模式获取已经不能满足实时性要求,高频率... 随着面向服务架构的大规模分布式系统的应用,多个系统之间由于数据集成的需要,彼此间要高并发传递大量数据,特别是状态数据的同步,对数据的实时性要求越来越高。数据单纯通过客户端以Pull(拉取)模式获取已经不能满足实时性要求,高频率服务调用也会给服务端数据库带来较大的压力。单纯通过服务端以Push(推送)模式推送给客户端也不能满足客户端对个性化数据的需求,大量推送既会给服务端带来较大压力,又会造成客户端数据处理不及时。本文针对高并发数据共享系统应用过程中产生的性能问题,提出一种基于pub/sub消息处理的Push-Pull混合模式优化方案,实践表明该方案极大地提高了系统可用性及数据安全性,对同类系统的性能优化具有较好的借鉴作用。 展开更多
关键词 高并发 数据共享系统 性能优化 pub/sub消息处理 push-pull混合模式
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Push-Pull型不对称钴(III)咔咯的合成与性质 被引量:1
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作者 张振 温俊霞 +2 位作者 张生玉 朱卫华 梁旭 《合成化学》 CAS 北大核心 2020年第9期759-763,共5页
酸催化下,在水-甲醇体系中,合成并分离了3种含有Push-Pull取代基的新型低对称A2B型钴(III)咔咯,其结构经1H NMR,19F NMR和HR-MS(ESI-TOF)表征。并利用光谱学和电化学方法对3种钴咔咯的电子结构进行了深入研究。结果表明:引入Push-Pull... 酸催化下,在水-甲醇体系中,合成并分离了3种含有Push-Pull取代基的新型低对称A2B型钴(III)咔咯,其结构经1H NMR,19F NMR和HR-MS(ESI-TOF)表征。并利用光谱学和电化学方法对3种钴咔咯的电子结构进行了深入研究。结果表明:引入Push-Pull型不对称对钴(III)咔咯分子的电子结构有明显的调控作用,且随着引入基团的改变而产生显著的规律性差异,为进一步的分子设计、合成及其应用奠定基础。 展开更多
关键词 push-pull型咔咯 光谱性质 电化学性质 电子结构 合成
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Exploiting push-pull strategy to combat the tea green leafhopper based on volatiles of Lavandula angustifolia and Flemingia macrophylla 被引量:10
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作者 HAN Shan-jie WANG Meng-xin +3 位作者 WANG Yan-su WANG Yun-gang CUI Lin HAN Bao-yu 《Journal of Integrative Agriculture》 SCIE CAS CSCD 2020年第1期193-203,共11页
Thirteen volatile compounds were identified from Flemingia macrophylla plants. Eight major components significantly attracted the tea green leafhoppers, Empoasca flavescens F. Based on their relative abundances, follo... Thirteen volatile compounds were identified from Flemingia macrophylla plants. Eight major components significantly attracted the tea green leafhoppers, Empoasca flavescens F. Based on their relative abundances, following synthetic blends were made for field experiments: 1) eight-component-attractant blend included Z-3-hexen-1-ol, Z-3-hexenyl acetate, Z-ocimene, Me SA, Z-3-hexenyl butyrate, dodecane, hexadecane and nonanal at 10, 10, 1, 11, 2, 6, 2 and 4 mg mL^-1 in n-hexane, respectively;2) four-component-attractant blend #1 contained hexadecane, Z-3-hexenyl acetate, Z-3-hexen-1-ol and nonanal at 2, 10, 10 and 4 mg mL^-1 in n-hexane, respectively;3) four-component-attractant blend #2 contained hexadecane, Z-3-hexenyl acetate, Z-3-hexen-1-ol and Me SA at 2, 10, 10 and 11 mg mL^-1 in n-hexane, respectively. Thymol and 1-methoxy-4-methyl-2-(1-methylethyl)-benzene, identified from Lavandula angustifolia aeration samples, significantly repelled the leafhopper as strong repellents when tested alone or in combination at 10 mg mL^-1. For field bioassays, each attractant lure was attached to a bud green sticky board hung from a bamboo stick at above tea plant level for catching the leafhoppers, whereas the repellent dispenser was tied to a tea branch inside tea clump for pushing the leafhoppers away from tea clumps. The results showed that the eight-component-attractant blend caught similar numbers of the leafhopper as did the four-component-attractant blend #1 at about 53–79 leafhoppers/trap/day, which were significantly higher than those on the hexane-control bud green sticky boards. Average leafhopper catches from un-baited sticky boards were about 51–73 leafhoppers/trap/day when pushed by the repellents placed inside tea plants, with the two-component-repellent blend being more effective than their single components. When the two-component-repellent blend was further tested with the three attractant blends in a push-pull fashion, average trap catches ranged from 62 to 92 leafhoppers/trap/day. Control efficacy on the leafhoppers within the push-pull zones increased progressively from day 1(43%) to day 5(73%). This push-pull approach might have a great potential as a green control strategy for combating the tea green leafhoppers. 展开更多
关键词 push-pull strategy ATTRACTANTS REPELLENTS Flemingia macrophylla tea green leafhopper tea plantation
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Influential Factors in Employment Location Selection Based on “Push-Pull” Migration Theory—A Case Study in Three Gorges Reservoir Area in China 被引量:10
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作者 XU Ding-de ZHANG Ji-fei +3 位作者 XIE Fang-ting LIU Shao-quan CAO Meng-tian LIU En-lai 《Journal of Mountain Science》 SCIE CSCD 2015年第6期1562-1581,共20页
In China, farmers employed in non-farm work have become important socio-economic actors, but few studies have examined the farmers' perspective in making their work location choices. Based on "push-pull"... In China, farmers employed in non-farm work have become important socio-economic actors, but few studies have examined the farmers' perspective in making their work location choices. Based on "push-pull" migration theory, this paper utilizes sectional data from a 2013 survey of farmers in China's Three Gorges Reservoir area to empirically analyze the factors influencing migrant workers' choice of employment location. The results indicate that 60.46% of laborers have migrated from their home province, whereas 39.54% have remained in their home province. Focusing on personal, household, and community characteristics—in addition to the economic characteristics of the sample counties—multinomial logistic regression models reveal that farmer-laborers' employment location decisions are influenced by their personal capital endowment(age, years of education and social networks), family structure(the number of laborers, elders, children and students), home village characteristics(location, economic development level and the degree of relief of the land) and home county economic development level. Notably, male and female laborers' location decisions reveal a converging trend, and their differences are not pronounced. Per capita arable land area has little influence on location decisions, whereas the educational level of laborers has a significant impact. The results differ significantly from those found in previous studies. 展开更多
关键词 Off-farm employment Location selection Migrants push-pull migration theory Three Gorges Reservoir region China
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Push-Pull Finite-Time Convergence Distributed Optimization Algorithm 被引量:1
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作者 Xiaobiao Chen Kaixin Yan +3 位作者 Yu Gao Xuefeng Xu Kang Yan Jing Wang 《American Journal of Computational Mathematics》 2020年第1期118-146,共29页
With the widespread application of distributed systems, many problems need to be solved urgently. How to design distributed optimization strategies has become a research hotspot. This article focuses on the solution r... With the widespread application of distributed systems, many problems need to be solved urgently. How to design distributed optimization strategies has become a research hotspot. This article focuses on the solution rate of the distributed convex optimization algorithm. Each agent in the network has its own convex cost function. We consider a gradient-based distributed method and use a push-pull gradient algorithm to minimize the total cost function. Inspired by the current multi-agent consensus cooperation protocol for distributed convex optimization algorithm, a distributed convex optimization algorithm with finite time convergence is proposed and studied. In the end, based on a fixed undirected distributed network topology, a fast convergent distributed cooperative learning method based on a linear parameterized neural network is proposed, which is different from the existing distributed convex optimization algorithms that can achieve exponential convergence. The algorithm can achieve finite-time convergence. The convergence of the algorithm can be guaranteed by the Lyapunov method. The corresponding simulation examples also show the effectiveness of the algorithm intuitively. Compared with other algorithms, this algorithm is competitive. 展开更多
关键词 DISTRIBUTED Optimization FINITE Time CONVERGENCE Linear Parameterized NEURAL Network push-pull Algorithm Undirected Graph
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Comparison of the severity of injury of hippocampal neuron in rats induced by simulated push-pull maneuver at various degrees
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作者 Suhong Guo Hui Zhang 《Neural Regeneration Research》 SCIE CAS CSCD 2006年第1期10-13,共4页
BACKGROUND: Push-pull effect is often caused during maneuver, and the changes of unconsciousness induced can affect or damage cerebral neurons at various degrees. OBJECTIVE: To observe the effect of simulated push-p... BACKGROUND: Push-pull effect is often caused during maneuver, and the changes of unconsciousness induced can affect or damage cerebral neurons at various degrees. OBJECTIVE: To observe the effect of simulated push-pull maneuver at various degrees on injury of hippocampal neurons in rats and analyze its phase effect. DESIGN: Randomized control study.SETTING : Physiological Department of Jilin Medical College.MATERIALS: A total of 40 healthy male Wistar rats, of clean grade, weighting 205-300 g, aged 3-4 months, were randomly divided into control group (n=4) and three push-pull experimental groups, including +2 Gz group (intensity: -2 Gz to +2 Gz, n=12), +6 Gz group (-6 Gz to +6 Gz, n=12) and +8 Gz group (-8 Gz to +8 Gz, n=12).METHODS: The experiment was completed in the Physiological Department of Jilin Military Medical College from March 2002 to May 2003. ① Rats in the experimental groups were put at the specially rolling arm of animal centrifugal machine. Then, they were pushed and pulled with ±2 Gz, ±6 Gz and ±8 Gz, respectively. The jolt was 1 Gz/s. However, rats in control group were not treated with any ways. ② Stroke index and neurological evaluation were performed on rats in the experimental groups at 0.5, 6 and 24 hours after push-pull. Stroke index was 25 points in total. The higher the scores were, the severer the cerebral injury was. Neurological evaluation was 10 points in total. The higher the scores were, the severer the nerve injury was. ③ Hippocampal tissue in brain of rats were selected to cut into sections at each time points, and form and distribution of neurons were observed in hippocampal areas with HE staining. Degrees of neuronal injury in hippocampal CA1 area were assayed after push-pull at various degrees with electron microscope. ④ Measurement data were compared with t test.MAIN OUTCOME MEASURES:① Stroke index and neurological evaluation; ② form and distribution of neurons in hippocampal areas;③ degrees of neuronal injury in hippocampal CA1 area.RESULTS: A total of 40 rats were involved in the final analysis. ① Stroke index and neurological evaluation of rats in experimental groups: At 30 minutes and 6 hours after push-pull exposure, stroke index and neurological evaluation were higher in ±6Gz group and ±8 Gz group than those in control group (P 〈 0.01), especially at 6 hours after push-pull exposure, those in ±8 Gz group were the highest at each time points [(11.00±2.16), (5.75±1.70) points]. At 24 hours after exposure, those were decreased as compared with those within the former two time points, but the values were still higher than those in control group (P 〈 0.05-0.01). ② Results of HE staining: At 6 and 24 hours after exposure, partially neuronal degeneration was observed in pyramidal layer in ±6 Gz group and ±8 Gz group, including crenation of neurons, tdangle or polygon, and karyopycnosis, especially the injury in ±8 Gz group was the most obvious at 6 hours after exposure. ③ Results of ultrastructure with electron microscope: Partially neuronal degeneration at various degrees was observed in hippocampal CA1 area in ±2 Gz group at 6 hours after exposure and in ±6 Gz group and ±8 Gz group at 6 and 24 hours after exposure. At 6 hours after exposure, nucleus of hippocampal neurons in ±8 Gz group was irregular and umbilication. Caryotin was aggregated, nuclear matrix was swelled and disorder, and vacuolation was also observed. Rough endoplasmic reticulum was expanded, mitochondrium was swelled, and crista was disappeared.CONCLUSION: ① Push-pull cannot damage hippocampal neurons of rats in ±2 Gz group. ② Exposure can cause injury of hippocampal neurons of rats in ±6Gz group and ±8 Gz group, especially the injury is the severest at 6 hours after exposure in ±8 Gz group and relieves gradually 24 hours later. 展开更多
关键词 Comparison of the severity of injury of hippocampal neuron in rats induced by simulated push-pull maneuver at various degrees
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A Case Study of China as an Exporter of Higher Education Using Push-Pull Theory
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作者 Zhang Li 《Review of Global Academics》 2014年第4期277-292,共16页
Developing countries establishing international branch campuses (IBCs) is an emerging trend, and currently compromises 17% percent of the market in terms of the number of IBCs. While researchers have applied differe... Developing countries establishing international branch campuses (IBCs) is an emerging trend, and currently compromises 17% percent of the market in terms of the number of IBCs. While researchers have applied different social science perspectives to analyze cross-border higher education and IBCs, they usually emphasize developed countries as exporters and developing countries as importers of higher education. The phenomenon of developing countries as exporters of higher education has seldom been looked at so far in the research. This paper first describes the current development of IBCs, then illustrates what social science perspectives have been used on this topic, followed by how push-pull theory relates to developing countries being exporters of IBCs. The paper aims to combine E.S. Lee's push-pull theory and Gu's push-pull framework to analyze the push and pull factors in their advertisement and marketing claims when higher education institutions (HEIs) from developing countries plan to establish branch campuses in foreign countries. Soochow University in Laos is used as a case study. Furthermore, intermediate barriers and solutions are also identified in this case study. However, this case study has its own uniqueness and only serves heuristic for future research. 展开更多
关键词 push-pull theory international branch campuses cross-border higher education importers and exporters of higher education
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Basic Study on Perfect Push-Pull Local Ventilation
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作者 Yukihiro Hattori Koichi Nakabayashi +1 位作者 Osami Kitoh Motoyuki Ito 《Journal of Energy and Power Engineering》 2012年第12期1940-1944,共5页
In this study, the authors experimentally investigated the changes of the mean velocity component profiles, half-widths (b12), turbulence intensities, Reynolds shear stress and intermittency of turbulence of a trans... In this study, the authors experimentally investigated the changes of the mean velocity component profiles, half-widths (b12), turbulence intensities, Reynolds shear stress and intermittency of turbulence of a transient plane turbulent jet developing from a jet exit into a hood opening. The values of maximum mean-velocity and half-widths of the axial velocity profile along the center-line of the jet are greater than those for a fully developed two-dimensional jet. Turbulence intensity in the axial direction is not affected by the flow rate ratio. At the same time, turbulence intensity in the lateral direction becomes greater as the hood is approached and the flow rate ratio Q3/Q1 becomes larger (QI is jet flow rate from nozzle and Q3 is suction flow rate produced by the hood). These experimental results are in accord with the distributions of production terms in the axial and lateral directions. Reynolds shear stress becomes smaller as the flow rate ratio becomes larger near the hood. Dimensionless distance y1/br2, from the center axis of the flow to the point where intermittency factor y becomes a constant value, narrows as the flow rate ratio becomes larger near the hood. 展开更多
关键词 Turbulence intensity intermittency factor Reynolds shear stress push-pull ventilation.
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秸秆还田及过程因素对土壤氮素影响的Meta分析
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作者 黄增健 李江 +2 位作者 缴锡云 郭维华 顾哲 《灌溉排水学报》 CAS CSCD 2024年第7期93-97,共5页
【目的】评估秸秆还田过程中不同因素对农田土壤氮素水平的影响。【方法】基于Meta分析,在中国知网、Web of Science及Science of Direct搜集秸秆还田文献42篇,共得到314对数据,量化秸秆种类、土壤初始条件、秸秆还田方式、秸秆还田量... 【目的】评估秸秆还田过程中不同因素对农田土壤氮素水平的影响。【方法】基于Meta分析,在中国知网、Web of Science及Science of Direct搜集秸秆还田文献42篇,共得到314对数据,量化秸秆种类、土壤初始条件、秸秆还田方式、秸秆还田量、氮肥配施量以及秸秆还田年限对土壤氮素水平的影响。【结果】不同种类秸秆还田均能够提高土壤总氮量;相比黏土,秸秆还田更有利于促进砂土和壤土的氮素积累;在碱性土壤条件下进行秸秆还田,土壤固氮效果较好;秸秆还田后土壤氮素提升率随土壤碳氮比的增加而下降;采用翻耕、旋耕和免耕进行秸秆还田分别提升了9.11%、7.84%、5.34%的土壤总氮量;秸秆还田过程中少量(≤150 kg/hm^(2))和中量(150~250 kg/hm^(2))配施氮肥条件下的土壤固氮效果较为接近,氮肥施用量˃250 kg/hm^(2)时,土壤氮素积累效果显著提升;长期秸秆还田(>10 a)与短期秸秆还田(1~4 a)取得的土壤增氮效果接近。【结论】碱性、低碳氮比的非黏性土壤更有利于秸秆腐解及氮素释放,为促进土壤氮素积累,建议在合理配施氮肥条件下将秸秆以翻耕的方式进行中短期(≤10a)还田。 展开更多
关键词 秸秆 还田 土壤 氮素 META分析
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一种低功耗快速瞬态响应无片外电容LDO
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作者 於汉 张涛 《电子元件与材料》 CAS 北大核心 2024年第6期713-720,共8页
针对无片外电容LDO瞬态响应问题,提出了一种基于Miller BICMOS OTA结构的N型功率管LDO。BJT Push-Pull作为电路的中间级,具有低功耗、高增益、高摆率的特点。输出扰动通过电容耦合至中间级,形成了一条快速反馈环路,拓展了反馈环路带宽,... 针对无片外电容LDO瞬态响应问题,提出了一种基于Miller BICMOS OTA结构的N型功率管LDO。BJT Push-Pull作为电路的中间级,具有低功耗、高增益、高摆率的特点。输出扰动通过电容耦合至中间级,形成了一条快速反馈环路,拓展了反馈环路带宽,提高了负载瞬态响应速度。因为输出级为源随器,系统整体为两级运放结构,仅需通过密勒电容进行补偿,就可以获得良好的稳定性。电路基于Hynix 180 nm BCD工艺设计,仿真结果显示,系统静态电流约为10μA,增益约为102 dB,带宽约为800 kHz,相位裕度约为61°,其中反馈环路带宽约为30 MHz。当输入电压为5 V,不接片外电容,负载电容为5 pF,输出电流从20 mA切换到200μA用时300 ps时,系统响应时间约为420 ps,过冲电压约为253 mV。 展开更多
关键词 NMOS BICMOS OTA BJT push-pull 前馈电容
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秸秆还田与改良剂对盐碱土化学性质和养分的影响
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作者 于博 杨哲 +7 位作者 王钰艳 马扬 郭艳 张一博 任琴 穆俊祥 徐松鹤 张学峰 《中国农学通报》 2024年第32期50-55,共6页
乌兰察布市盐碱地面积占土地面积近1/5,盐碱地土壤肥力低,造成农作物产量偏低。本研究针对乌兰察布市盐碱地土壤肥力低下、农作物产量偏低的问题,在白海子镇庞家村和平地泉镇南村进行了秸秆还田和化学改良剂Al_(2)(SO_(4))_(3)和FeSO_(4... 乌兰察布市盐碱地面积占土地面积近1/5,盐碱地土壤肥力低,造成农作物产量偏低。本研究针对乌兰察布市盐碱地土壤肥力低下、农作物产量偏低的问题,在白海子镇庞家村和平地泉镇南村进行了秸秆还田和化学改良剂Al_(2)(SO_(4))_(3)和FeSO_(4)处理的田间试验。以未进行秸秆还田和不施用改良剂的盐碱田土壤作为对照,测定了0~40 cm土层的土壤pH、电导率、有机质、全氮和速效养分。结果表明:(1)秸秆还田和化学改良剂都显著降低了0~40 cm土层土壤pH、电导率和土壤盐分。(2)秸秆还田和化学改良剂都显著提高了耕层土壤全氮和土壤有机质。(3)秸秆还田和化学改良剂都显著提高了耕层土壤速效养分。综上,秸秆还田和化学改良剂显著降低了盐碱田耕层和犁底层土壤pH和电导率,显著增加了土壤有机质、全氮和速效养分,化学改良剂对盐碱田的改良效果更优于秸秆还田处理。本研究为乌兰察布市盐碱田改良与培肥和高标准农田建设提供理论和技术支撑,有助于保证粮食稳产,保障地区和国家粮食安全。 展开更多
关键词 盐碱田 秸秆还田 电导率 有机质 速效养分 化学改良剂 土壤PH 土壤有机质 全氮
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Electron push-pull effects induced performance promotion in covalent organic polymer thin films-based memristor for neuromorphic application
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作者 Panke Zhou Hong Yu +6 位作者 Mun Yin Chee Tao Zeng Tianli Jin Hongling Yu Shuo Wu Wen Siang Lew Xiong Chen 《Chinese Chemical Letters》 SCIE CAS CSCD 2024年第5期227-231,共5页
Covalent organic polymer(COP)thin film-based memristors have generated intensive research interest,but the studies are still in their infancy.Herein,by controlling the content of hydroxyl groups in the aldehyde monome... Covalent organic polymer(COP)thin film-based memristors have generated intensive research interest,but the studies are still in their infancy.Herein,by controlling the content of hydroxyl groups in the aldehyde monomer,Py-COP thin films with different electronic push-pull effects were fabricated bearing distinct memory performances,where the films were prepared by the solid-liquid interface method on the ITO substrates and further fabricated as memory devices with ITO/Py-COPs/Ag architectures.The Py-COP-1-based memory device only exhibited binary memory behavior with an ON/OFF ratio of 1:10^(1.87).In contrast,the device based on Py-COP-2 demonstrated ternary memory behavior with an ON/OFF ratio of 1:10^(0.6):10^(3.1) and a ternary yield of 55%.The ternary memory mechanism of the ITO/Py-COP-2/Ag memory device is most likely due to the combination of the trapping of charge carriers and conductive filaments.Interestingly,the Py-COPs-based devices can successfully emulate the synaptic potentiation/depression behavior,clarifying the programmability of these devices in neuromorphic systems.These results suggest that the electronic properties of COPs can be precisely tuned at the molecular level,which provides a promising route for designing multi-level memory devices. 展开更多
关键词 Covalent organic polymers push-pull effects Multi-level memory MEMRISTOR
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有机钾与化学钾肥配施对黔中马铃薯产量、品质及钾素平衡的影响 被引量:12
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作者 胡岗 赵欢 +1 位作者 秦松 肖厚军 《中国土壤与肥料》 CAS CSCD 北大核心 2020年第3期55-62,共8页
为探究秸秆钾与化学钾肥配施对黔中地区马铃薯产量、品质及土壤钾平衡的影响,为黔中地区秸秆钾和钾肥资源合理利用提供科学依据。以马铃薯宣薯2号为供试作物,设置不施钾肥(NP)、化学钾肥(NPK)、秸秆钾肥(S)、化学钾肥+秸秆钾肥(NPKS)、... 为探究秸秆钾与化学钾肥配施对黔中地区马铃薯产量、品质及土壤钾平衡的影响,为黔中地区秸秆钾和钾肥资源合理利用提供科学依据。以马铃薯宣薯2号为供试作物,设置不施钾肥(NP)、化学钾肥(NPK)、秸秆钾肥(S)、化学钾肥+秸秆钾肥(NPKS)、高量化学钾肥(NPK1)5个处理,研究秸秆钾与化肥钾对马铃薯产量、品质及土壤钾素平衡的影响。结果表明:在氮、磷养分满足的条件下,单施化学钾肥与秸秆钾、秸秆钾与化学钾肥配施,较NP均有明显增产效应,表现为NPKS>NPK1>NPK>S>NP,秸秆钾与化学钾肥配施增产效果最好,随着种植年限增长年度间产量变异系数变小,有利于稳产;养分吸收量与品质(淀粉、Vc含量)均随着钾素的增加逐渐增加,但还原糖、硝酸盐含量却随着钾素增加而逐渐降低;无论高、低钾素条件下,化学钾肥与秸秆钾对养分吸收量与品质影响都呈相似的趋势,仅钾吸收量、Vc含量达到差异显著水平。土壤钾素表观盈亏来看,土壤钾素含量为129.2 kg/hm2时能满足马铃薯生长所需。因此,高钾情况下土壤钾素处于盈余状态,NPKS、NPK1、NPK、S处理的钾素表观平衡系数分别为1.36、1.51、0.65、0.63。综上所述,在施用充足氮、磷肥的基础上,秸秆钾与化学钾肥配施(施钾量225 kg/hm^2)显著增加马铃薯产量、养分吸收和品质的同时,有利于钾素的收支平衡,减轻马铃薯对土壤钾素的耗竭,可维持土壤钾素肥力的稳定,也减少因气候因素等影响引起的产量变异,提高了产量的稳定性。 展开更多
关键词 马铃薯产量 钾素 品质 养分吸收 秸秆还田
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Lappaconitine solid dispersion monolithic osmotic tablet and lappaconitine push-pull osmotic pump: preparation and comparison of their release performance in vitro 被引量:3
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作者 吴先闯 王姣姣 +4 位作者 郝海军 宋晓勇 张永州 刘瑜新 张红芹 《Journal of Chinese Pharmaceutical Sciences》 CAS CSCD 2017年第6期413-422,共10页
Lappaconitine is a water-insoluble drug, which was used as model drug in this study. Currently, two osmotically controlled delivery systems that are widely used for water-insoluble drug are monolithic osmotic tablet ... Lappaconitine is a water-insoluble drug, which was used as model drug in this study. Currently, two osmotically controlled delivery systems that are widely used for water-insoluble drug are monolithic osmotic tablet (MOT) and push-pull osmotic pump (PPOP). In the present study, lappaconitine solid dispersion monolithic osmotic tablet (lappaconitine-SD-MOT) and lappaconitine-PPOP were developed. The prepared lappaconitine-PPOP was able to delivery drug at the rate of approximate zero-order (r = 0.9931), and the cumulative release was above 95.0%. The lappaconitine-SD-MOT showed a comparatively poor linearity when the data were plotted according to the zero-order equation (r = 0.9798), and the cumulative release was 84.69%. Lappaconitine-PPOP exhibited better controlled drug release (higher regression value) compared with lappaconitine-SD-MOT. The similarity index (f2) between lappaconitine-PPOP and lappaconitine-SD-MOT was 49.1 (〈50). A clear difference of drug release characteristics between the lappaconitine-SD-MOT and lappaconitine-PPOP was revealed. It indicated that the drug release performance of lappaconitine-PPOP could gain favorable zero-order kinetics and higher cumulative release compared with lappaconitine-SD-MOT. Therefore, these results suggested that PPOP was still a very effective device for the delivery of poorly water-soluble drug with zero-order pattern. 展开更多
关键词 LAPPACONITINE Solid dispersion Monolithic osmotic tablet push-pull osmotic pumps
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新时代中国武术发展的立场选择:回归“主体” 被引量:11
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作者 黎桂华 韩金清 +3 位作者 李臣 刘国立 秦远见 王岗 《武汉体育学院学报》 CSSCI 北大核心 2019年第8期62-68,共7页
彰显中华文化显著基因的中国武术在发展中存在着过度学习“体育”的现象。在促进文化繁荣、凸显文化自信、坚守中华文化立场的时代背景下,回归中国武术的文化“主体”立场,成为了新时代中国武术发展的必要选择。运用文献资料和逻辑分析... 彰显中华文化显著基因的中国武术在发展中存在着过度学习“体育”的现象。在促进文化繁荣、凸显文化自信、坚守中华文化立场的时代背景下,回归中国武术的文化“主体”立场,成为了新时代中国武术发展的必要选择。运用文献资料和逻辑分析等研究方法从过度“学习”与坚守“主体”两种不同文化立场的发展终局开始论述,论证了只有坚持文化“主体”的发展,才能实现真正的中华文化繁荣;从中国武术近代发展的历程进行梳理,证实中国武术一直处在过度学习“体育”的立场当中。研究最后认为:中国武术的发展立场回归文化“主体”,才能更好地坚守中华文化立场,承担在新时代中助推中国梦实现的重大责任。 展开更多
关键词 中国武术 武术发展 立场选择 回归主体 中华文化
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江苏省小麦秸秆养分垂直分布特征与不同茬高下麦秸养分归还量估算 被引量:4
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作者 顾克军 顾东祥 +5 位作者 张斯梅 张传辉 石祖梁 许博 杨四军 常志州 《农业资源与环境学报》 CAS 2015年第6期537-544,共8页
为明确小麦植株不同层次的秸秆养分特征,科学估算不同留茬高度下麦秸养分还田量,通过采集江苏省生产上主推的9个春性品种和16个半冬性小麦品种植株,用分层切断法,将秸秆从基部向上依次截取4段长度为5 cm的秸秆,剩余部分为第5段(分别用0... 为明确小麦植株不同层次的秸秆养分特征,科学估算不同留茬高度下麦秸养分还田量,通过采集江苏省生产上主推的9个春性品种和16个半冬性小麦品种植株,用分层切断法,将秸秆从基部向上依次截取4段长度为5 cm的秸秆,剩余部分为第5段(分别用0~5、5~10、10~15、15~20 cm和〉20 cm表示5段秸秆),对穗部单独进行脱粒处理获取颖壳与穗轴,对植株各部分秸秆分别进行烘干称重,并进行养分分析。结果表明:在基部0~20 cm范围内,4个层次秸秆干重占植株秸秆干重的比例都表现为半冬性品种大于春性品种,20 cm以上部分则相反;在同一空间层次上,春性品种的秸秆氮(N)与磷(P)含量高于半冬性品种,而秸秆钾(K)含量低于半冬性品种;春性小麦品种秸秆N与P含量都呈现出从基部向顶部依次递减的趋势,半冬性小麦品种从基部向上秸秆N含量变化不大,而P含量呈“U”型变化,两类品种秸秆K含量都表现为从基部向顶部依次增加的趋势。在留茬10~20 cm且秸秆还田量大致相同的情况下,与春性品种相比,半冬性品种秸秆N归还量高23.4%~26.9%,秸秆P归还量高16.7%~30.8%,而秸秆K归还量低20.4%~25.9%。江苏省小麦秸秆N、P、K总量分别为10.20×10^4、1.16×10^4t和19.52×10^4t,在留茬15 cm高时,小麦秸秆N、P、K养分归还量分别为4.90×10^4、0.56×10^4t和8.47×10^4t。江苏省2种类型小麦品种秸秆养分含量不同,在麦秸还田后不同麦区的养分管理策略应有所不同。 展开更多
关键词 小麦 秸秆养分 留茬高度 秸秆还田
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