期刊文献+
共找到319篇文章
< 1 2 16 >
每页显示 20 50 100
Wetting alternating with partial drying during grain filling increases lysine biosynthesis in inferior rice grain
1
作者 Yi Jiang Wenli Tao +2 位作者 Weiyang Zhang Zhiqin Wang Jianchang Yang 《The Crop Journal》 SCIE CSCD 2024年第1期262-270,共9页
Lysine content is a criterion of the nutritional quality of rice.Understanding the process of lysine biosynthesis in early-flowering superior grain(SG)and late-flowering inferior grain(IG)of rice would advance breedin... Lysine content is a criterion of the nutritional quality of rice.Understanding the process of lysine biosynthesis in early-flowering superior grain(SG)and late-flowering inferior grain(IG)of rice would advance breeding and cultivation to improve nutritional quality.However,little information is available on differences in lysine anabolism between SG and IG and the underlying mechanism,and whether and how irrigation regimes affect lysine anabolism in these grains.A japonica rice cultivar was grown in the field and two irrigation regimes,continuous flooding(CF)and wetting alternating with partial drying(WAPD),were imposed from heading to the mature stage.Lysine content and activities of key enzymes of lysine biosynthesis,and levels of brassinosteroids(BRs)were lower in the IG than in the SG at the early grainfilling stage but higher at middle and late grain-filling stages.WAPD increased activities of these key enzymes,BR levels,and contents of lysine and total amino acids in IG,but not SG relative to CF.Application of 2,4-epibrassinolide to rice panicles in CF during early grain filling reproduced the effects of WAPD,but neither treatment altered the activities of enzymes responsible for lysine catabolism in either SG or IG.WAPD and elevated BR levels during grain filling increased lysine biosynthesis in IG.Improvement in lysine biosynthesis in rice should focus on IG. 展开更多
关键词 BRASSINOSTEROIDS Inferior grain Lysine biosynthesis Rice wetting alternating with partial drying
下载PDF
Effects of freeze-thaw cycle and dry-wet alternation on slope stability
2
作者 YaLing Chou LiYuan Sun +1 位作者 BaoAn Li XiaoLi Wang 《Research in Cold and Arid Regions》 CSCD 2019年第2期159-172,共14页
The typical loess on high slopes along the BaoLan High-speed Rail, China, was selected as the research object. The influence of the freeze-thaw cycle and dry-wet alternation on the shear-strength parameters of the uns... The typical loess on high slopes along the BaoLan High-speed Rail, China, was selected as the research object. The influence of the freeze-thaw cycle and dry-wet alternation on the shear-strength parameters of the unsaturated loess was investigated by laboratory experimental methods. Moreover, the temperature field, seepage field, and stability of slopes with different gradients were simulated under the effect of the freeze-thaw cycle and dry-wet alternation by using the geotechnical analysis software Geo-Studio. The research results showed(1) when the freeze-thaw cycle was repeated on the slope, with the frozen depth increasing, the melted depth did the same; besides, the closed loop of isotherms formed on the slope;(2) under the action of dry-wet circulation, the negative pore-water pressure and volumetric water content showed an upward tendency. However, owing to the different slope gradients, rainfall infiltration was not the same. As time went by, the differences of the negative pore-water pressure and volumetric water content between the slopes of different gradients continued to increase;(3) with the freeze-thaw cycle and dry-wet alternation increasing, the slope-safety factor decreased. Especially in the early period, the slope-safety factor changed remarkably. For slopes undergoing freeze-thaw action, the slope-safety factor was negatively correlated with the gradient. However, with regard to slopes undergoing dry-wet alternation, the result became more complex because the slope-safety factor was related to both seepage strength and slope grade. Accordingly, further research is needed to study the effect of seepage strength and slope grade on the stability of loess slopes. 展开更多
关键词 FREEZE-THAW action dry-wet alternation temperature FIELD SEEPAGE FIELD slope stability
下载PDF
Diversity of Arbuscular Mycorrhizal Fungi Associated with Six Rice Cultivars in Italian Agricultural Ecosystem Managed with Alternate Wetting and Drying 被引量:1
3
作者 Veronica VOLPE Franco MAGURNO +2 位作者 Paola BONFANTE Stefano GHIGNONE Erica LUMINI 《Rice science》 SCIE CSCD 2023年第4期348-358,I0028-I0030,共14页
Alternate wetting and drying(AWD)system,in which water has been reduced by approximately 35%with an increased occurrence of beneficial arbuscular mycorrhizal(AM)symbiosis and no negative impact on rice yield,was propo... Alternate wetting and drying(AWD)system,in which water has been reduced by approximately 35%with an increased occurrence of beneficial arbuscular mycorrhizal(AM)symbiosis and no negative impact on rice yield,was proposed to utilize water and nutrients more sustainable.In this study,we selected six rice cultivars(Centauro,Loto,Selenio,Vialone nano,JSendra and Puntal)grown under AWD conditions,and investigated their responsiveness to AM colonization and how they select diverse AM taxa.In order to investigate root-associated AM fungus communities,molecular cloning-Sanger sequencing on small subunit rDNA data were obtained from five out of the six rice cultivars and compared with Next Generation Sequencing(NGS)data,which were previously obtained in Vialone nano.The results showed that all the cultivars were responsive to AM colonization with the development of AM symbiotic structures,even if with differences in the colonization and arbuscule abundance in the root systems.We identified 16 virtual taxa(VT)in the soil compartment and 7 VT in the root apparatus.We emphasized that the NGS analysis gives additional value to the results thanks to a more in-depth reading of the less represented AM fungus taxa. 展开更多
关键词 alternate wetting and drying system arbuscular mycorrhizal fungi rice molecular diversity virtual taxa
下载PDF
Grain yield and water use efficiency of super rice under soil water deficit and alternate wetting and drying irrigation 被引量:25
4
作者 ZHOU Qun JU Cheng-xin +4 位作者 WANG Zhi-qin ZHANG Hao LIU Li-jun YANG Jian-chang ZHANG Jian-hua 《Journal of Integrative Agriculture》 SCIE CAS CSCD 2017年第5期1028-1043,共16页
This study investigated if super rice could better cope with soil water deficit and if it could have better yield performance and water use efficiency (WUE) under alternate wetting and drying (AWD) irrigation than... This study investigated if super rice could better cope with soil water deficit and if it could have better yield performance and water use efficiency (WUE) under alternate wetting and drying (AWD) irrigation than check rice. Two super rice cultivars and two elite check rice cultivars were grown in pots with three soil moisture levels, well watered (WW), moderate water deficit (MWD) and severe water deficit (SWD). Two cultivars, each for super rice and check rice, were grown in field with three irrigation regimes, alternate wetting and moderate drying (AWMD), alternate wetting and severe drying (AWSD) and conventional irrigation (CI). Compared with that under WW, grain yield was significantly decreased under MWD and SWD treatments, with less reduction for super rice than for check rice. Super rice had higher percentage of productive tillers, deeper root distribution, higher root oxidation activity, and greater aboveground biomass production at mid and late growth stages than check rice, especially under WMD and WSD. Compared with CI,AWMD increased, whereasAWSD decreased grain yield, with more increase or less decrease for super rice than for check rice. Both MWD and SWD treatments and eitherAWMD orAWSD regime significantly increased WUE compared with WW treatment or CI regime, with more increase for super rice than for check rice. The results suggest that super rice has a stronger ability to cope with soil water deficit and holds greater promising to increase both grain yield and WUE by adoption of moderate AWD irrigation. 展开更多
关键词 super rice soil water deficit alternate wetting and drying (AWD) grain yield water use efficiency
下载PDF
Influence of Seed Priming on Performance and Water Productivity of Direct Seeded Rice in Alternating Wetting and Drying 被引量:6
5
作者 Hafeez Ur REHMAN Muhammad KAMRAN +2 位作者 Shahzad Maqsood Ahmed BASRA Irfan AFZAL Muhammad FAROOQ 《Rice science》 SCIE CSCD 2015年第4期189-196,共8页
Direct seeded rice is promising alternative to traditional transplanting, but requires appropriate crop and water management to maintain yield performance and achieve high water productivity. Present study evaluated t... Direct seeded rice is promising alternative to traditional transplanting, but requires appropriate crop and water management to maintain yield performance and achieve high water productivity. Present study evaluated the effect of seed priming and irrigation on crop establishment, tillering, agronomic traits, paddy yield, grain quality and water productivity of direct seeded rice in alternate wetting and drying (DSR-AWD) in comparison with direct seeded rice at field capacity (DSR- FC). Seed priming treatments were osmo-priming with KCI (2.2%), CaCI2 (2.2%) and moringa leaf extracts (MLE, 3.3%) including hydro-priming as control. Among the treatments, seed osmo-primed with MLE emerged earlier and had higher final emergence, followed by osmo-priming with CaCI2. Tillering emergence rate and number of tillers per plant were the highest for seed priming with CaCI2 in DSR- AWD. Total productive and non-productive tillers, panicle length, biological and grain yields, harvest index were highest for seed priming with MLE or CaCI2 in DSR-AWD. Similarly, grain quality, estimated in terms of normal grains, abortive and chalky grains, was also the highest in DSR-AWD with MLE osmo-priming. Benefit cost ratio and water productivity was also the highest in DSR-AWD for seed priming with MLE. In conclusion, seed priming with MLE or CaCI2 can be successfully employed to improve the direct seeded rice performance when practiced with alternate wetting and drying irrigation. 展开更多
关键词 crop establishment grain filling rate seed priming water productivity YIELD direct seededrice alternating wetting and drying grain quality
下载PDF
Agronomic performance of drought-resistance rice cultivars grown under alternate wetting and drying irrigation management in southeast China 被引量:9
6
作者 Guang Chu Tingting Chen +3 位作者 Song Chen Chunmei Xu Danying Wang Xiufu Zhang 《The Crop Journal》 SCIE CAS CSCD 2018年第5期482-494,共13页
Compared to drought-susceptible rice cultivars(DSRs),drought-resistance rice cultivars(DRRs)could drastically reduce the amount of irrigation water input and simultaneously result in higher grain yield under water-sav... Compared to drought-susceptible rice cultivars(DSRs),drought-resistance rice cultivars(DRRs)could drastically reduce the amount of irrigation water input and simultaneously result in higher grain yield under water-saving irrigation conditions.However,the mechanisms underlying these properties are unclear.We investigated how improved agronomic traits contribute to higher yield and higher water use efficiency(WUE)in DRRs than in DSRs under alternate wetting and drying(AWD).Two DRRs and two DSRs were field-grown in 2015 and 2016 using two different irrigation regimes:continuous flooding(CF)and AWD.Under CF,no statistical differences in grain yield and WUE were observed between DRRs and DSRs.Irrigation water under the AWD regime was 275–349 mm,an amount 49.8%–56.2% of that(552–620 mm)applied under the CF regime.Compared to CF,AWD significantly decreased grain yield in both DRRs and DSRs,with a more significant reduction in DSRs,and WUE was increased in DRRs,but not in DSRs,by 9.9%–23.0% under AWD.Under AWD,DRRs showed a 20.2%–26.2% increase in grain yield and an 18.6%–24.5% increase in WUE compared to DSRs.Compared to DSRs,DRRs showed less redundant vegetative growth,greater sink capacity,higher grain filling efficiency,larger root biomass,and deeper root distribution under AWD.We conclude that these improved agronomic traits exert positive influences on WUE in DRRs under AWD. 展开更多
关键词 Agronomic traits alternate wetting and drying Drought-resistance rice cultivars Grain yield Water use efficiency
下载PDF
Monitoring the spontaneous wetting process of hydrophobic microporous membrane assisted by alternating current impedance spectroscopy 被引量:1
7
作者 Juntian Xiao Qian Sun +1 位作者 Liying Liu Zhongwei Ding 《Chinese Journal of Chemical Engineering》 SCIE EI CAS CSCD 2021年第11期96-102,共7页
In the process of membrane absorption,spontaneous wetting of hydrophobic microporous membrane causes membrane modification and increases membrane phase mass transfer resistance,which have attracted wide interest.Howev... In the process of membrane absorption,spontaneous wetting of hydrophobic microporous membrane causes membrane modification and increases membrane phase mass transfer resistance,which have attracted wide interest.However,due to the limitations of previous testing methods,the study of the spontaneous membrane wetting process is limited.Herein,we present a method for monitoring spontaneous membrane wetting by measuring its alternating current(AC)impedance.The impedance tests of the PVDF flat membranes and hollow fiber membranes were conducted in a two-electrode system.The results of equivalent circuit fitting indicate that the impedance value of the unwetted membrane is about 1.02×10^(10)Ω,which is close to the theoretical value of 1.4×10^(10)Ω,and this method can quantify the electrochemical impedance value of membranes with different degrees of spontaneous wetting.In addition,a method of impedance test for real-time monitoring of spontaneous wetting was designed.During the experiment,the timeliness and continuity of this method are confirmed with exact judgment under different conditions.In future work,the impedance data will be used to build model to predict the percentage of membrane wetting degree. 展开更多
关键词 alternating current impedance Spontaneous membrane wetting Hydrophobic membrane Dynamic monitoring
下载PDF
Acceleration of Selenate Reduction by Alternative Drying and Wetting of Soils 被引量:1
8
作者 朴河春 刘广深 +1 位作者 袁芷云 洪业汤 《Chinese Journal Of Geochemistry》 EI CAS 1996年第3期278-284,共7页
In nature selenate reduction and nitrate denitrification both folow a similar biogeochemical mechanism. It has been proved that abiotic stresses such as alternative drying and wetting can exert an important influence ... In nature selenate reduction and nitrate denitrification both folow a similar biogeochemical mechanism. It has been proved that abiotic stresses such as alternative drying and wetting can exert an important influence on nitrate denitrification as well as on selenate reduction. Our experimental results lend great support to the above conclusion. 展开更多
关键词 硒酸盐 硝酸盐 土壤湿度 生物地球化学 脱氮作用 有机物
下载PDF
干湿交替灌溉和施氮量对粳稻光合特性和氮素吸收利用的影响
9
作者 付景 马梦娟 +7 位作者 张骐飞 段居琦 王越涛 王付华 王生轩 白涛 尹海庆 王亚 《作物学报》 CAS CSCD 北大核心 2024年第7期1787-1804,共18页
水分和氮素对水稻叶片光合特性和氮素吸收利用有重要影响,但在干湿交替灌溉条件下,水、氮是如何影响水稻叶片和根系氮代谢酶活性、产量和氮素吸收利用的仍不清楚。探明这一问题对于协同提高产量和氮肥利用效率有重要意义。本研究以超级... 水分和氮素对水稻叶片光合特性和氮素吸收利用有重要影响,但在干湿交替灌溉条件下,水、氮是如何影响水稻叶片和根系氮代谢酶活性、产量和氮素吸收利用的仍不清楚。探明这一问题对于协同提高产量和氮肥利用效率有重要意义。本研究以超级稻品种南粳9108为材料,大田种植,设置全生育期常规灌溉(conventional irrigation,CI)和干湿交替灌溉(alternate wetting and drying irrigation,AWD)2种灌溉方式及5个施氮水平,不施氮(N0)、施氮90 kg hm^(-2)(N1)、施氮180 kg hm^(-2)(N2)、施氮270 kg hm^(-2)(N3)和施氮360 kg hm^(-2)(N4)。结果表明,与CI相比,AWD增加了水稻主要生育时期叶片的叶绿素a、叶绿素b、总叶绿素和类胡萝卜素含量,提高了叶片净光合速率,并显著增加了叶片中超氧化物歧化酶、过氧化氢酶、硝酸还原酶、谷氨酰胺合成酶和谷氨酸合成酶活性,显著降低了过氧化物酶、内肽酶活性和丙二醛含量,显著提高了根系中氮代谢酶硝酸还原酶、谷氨酰胺合成酶、谷氨酸合成酶和谷氨酸脱氢酶活性;AWD的产量较CI平均增加了10.4%。AWD显著提高了氮素转运量、氮素转运率、氮肥吸收利用率和氮肥偏生产力,产量和氮肥利用率均以AWD+N3处理组合的最高。因此,轻度干湿交替灌溉配合一定的施氮量,可以充分发挥水、肥效应,促进根系和叶片的氮代谢水平,提高叶片光合特性,协调地下地上部生长,有利于水稻产量和氮肥利用率的协同提高。 展开更多
关键词 水稻 干湿交替灌溉 施氮量 光合特性 氮代谢酶 氮素吸收利用
下载PDF
干旱区与湿润区旱涝急转演变特征对比研究
10
作者 薛联青 章郁涵 刘远洪 《水资源保护》 EI CAS CSCD 北大核心 2024年第4期1-8,共8页
以长江、黄河和淮河流域为研究对象,基于标准化旱涝急转指数,利用趋势分析、变点检验、小波分析、随机森林等方法探究典型干旱区与湿润区旱涝急转演变特征及其驱动因子。结果表明:湿润和半湿润区是极端旱涝急转事件的高频发生区,干旱区... 以长江、黄河和淮河流域为研究对象,基于标准化旱涝急转指数,利用趋势分析、变点检验、小波分析、随机森林等方法探究典型干旱区与湿润区旱涝急转演变特征及其驱动因子。结果表明:湿润和半湿润区是极端旱涝急转事件的高频发生区,干旱区是极端旱转涝事件的高频发生区;干旱区的突变发生在1998年,湿润区的突变在1978年,未来干旱区更易发生旱转涝事件,湿润区则相反;气象因子在湿润区对旱涝急转的贡献度更大,大气环流对干旱区的影响突出,旱涝急转与不同驱动因子间存在非线性关系。 展开更多
关键词 旱涝急转 标准化旱涝急转指数 大气环流 长江流域 黄河流域 淮河流域
下载PDF
南四湖消落带底泥中磷及微生物群落结构研究
11
作者 张彦浩 杨月彪 +2 位作者 赵强 周冉 张志斌 《山东建筑大学学报》 2024年第3期128-134,共7页
研究不同频率干湿交替条件下,南四湖消落带底泥磷形态变化及其与生物群落结构的关联性,可为维持南四湖消落带水生态系统健康及保障南四湖水质提供技术支持。文章模拟了南四湖消落带底泥不同频率干湿交替过程,通过高通量测序技术分析了... 研究不同频率干湿交替条件下,南四湖消落带底泥磷形态变化及其与生物群落结构的关联性,可为维持南四湖消落带水生态系统健康及保障南四湖水质提供技术支持。文章模拟了南四湖消落带底泥不同频率干湿交替过程,通过高通量测序技术分析了底泥生物群落的变化特征。结果表明:在干湿交替过程中,底泥总磷、无机磷呈降低趋势,而有机磷基本保持不变;不同干湿交替过程中消落带底泥微生物群落结构比较稳定,但群落丰度变化显著;频繁干湿交替不利于消落带底泥保持微生物多样性;消落带底泥中蓝藻门(Cyanobacteria)和疣微菌门(Verrucomicrobiota)与底泥中NaOH-P呈显著负相关,变形菌门(Proteobacteria)与总磷则呈正相关。 展开更多
关键词 消落带 南四湖 微生物群落结构 干湿交替
下载PDF
不同灌溉模式对籼粳杂交稻甬优1540产量与水分利用效率的影响 被引量:1
12
作者 徐冉 杨文叶 +6 位作者 朱均林 陈松 徐春梅 刘元辉 章秀福 王丹英 褚光 《作物学报》 CAS CSCD 北大核心 2024年第2期425-439,共15页
旨在探讨不同灌溉模式对籼粳杂交稻甬优1540产量与水分利用效率的影响,并阐明其相关生理基础。本研究以甬优1540为材料,设置了3种灌溉模式,即长淹灌溉(continuous flooding,CF)、轻度干湿交替灌溉(alternate wetting and moderate dryin... 旨在探讨不同灌溉模式对籼粳杂交稻甬优1540产量与水分利用效率的影响,并阐明其相关生理基础。本研究以甬优1540为材料,设置了3种灌溉模式,即长淹灌溉(continuous flooding,CF)、轻度干湿交替灌溉(alternate wetting and moderate drying, AWMD)以及重度干湿交替灌溉(alternate wetting and severe drying, AWSD)。研究结果表明,与CF相比, AWMD与AWSD均能显著提高水分利用效率,增幅分别为22.6%~25.6%与18.2%~23.1%;AWMD可以显著提高水稻产量,增幅为8.6%~10.0%,而AWSD则显著降低水稻产量,降幅为6.0%~7.5%。与CF相比, AWMD显著降低了拔节期水稻的茎蘖数、地上部干物质重、叶面积指数、移栽至齐穗期的光合势以及移栽至拔节期的作物生长速率,但显著提高了茎蘖成穗率、拔节至齐穗期的作物生长速率、主要生育期水稻根长密度、深根比、比根长、根系总吸收表面积与活跃吸收表面积,以及灌浆后2次土壤复水期的剑叶净光合速率、根系氧化力、根系与叶片中玉米素和玉米素核苷(Z+ZR)含量、籽粒中蔗糖-淀粉代谢途径关键酶活性等指标。以上结果表明, AWMD可以协同提高甬优1540产量与水分利用效率,优化根-冠生长发育特征,提高灌浆期植株生理活性,实现高产与水分高效利用,为本研究最佳水分管理模式。 展开更多
关键词 籼粳杂交稻 干湿交替灌溉 产量 水分利用率 根系形态与生理特征
下载PDF
斜发沸石对干湿交替条件下水稻产量和氮素累积的影响
13
作者 赵清 沙炎 +2 位作者 王术 陈涛涛 迟道才 《植物营养与肥料学报》 CAS CSCD 北大核心 2024年第5期922-933,共12页
【目的】斜发沸石作为一种优良的土壤改良剂,因其具有改善土壤养分、提高水稻产量、减少氮素流失等积极作用而广泛用于水稻生产中。通过田间定位试验,探究干湿交替灌溉条件下斜发沸石对水稻氮素吸收利用和产量的长期影响。【方法】在201... 【目的】斜发沸石作为一种优良的土壤改良剂,因其具有改善土壤养分、提高水稻产量、减少氮素流失等积极作用而广泛用于水稻生产中。通过田间定位试验,探究干湿交替灌溉条件下斜发沸石对水稻氮素吸收利用和产量的长期影响。【方法】在2017—2021年连续5年进行原位大田试验。试验设计为随机区组试验,设置常规淹灌条件下不施斜发沸石(I_(CF)Z_(0)),干湿交替灌溉下不施斜发沸石(I_(AWD)Z_(0))和干湿交替灌溉下施加10 t/hm^(2)斜发沸石(I_(AWD)Z_(10))3个处理,斜发沸石于2017年施入土壤,之后4年(2018—2021)不再施用。水稻生育期内定期取0—30 cm土壤样品用于测定无机氮含量,每年水稻成熟期,调查籽粒产量量及主要产量构成因子,计算地上部氮累积量、氮肥偏生产力。【结果】I_(CF)Z_(0)和I_(AWD)Z_(0)处理的水稻产量、地上部氮累积量和氮肥偏生产力差异均不显著。与I_(CF)Z_(0)和I_(AWD)Z_(0)处理相比,I_(AWD)Z_(10)处理连续5年均显著提高了地上部氮累积量和产量,但增长率随定位试验的延长有所下降。I_(AWD)Z_(10)处理氮肥偏生产力较I_(CF)Z_(0)和I_(AWD)Z_(0)处理分别增加了9.67~13.44和5.53~9.55 kg/kg,产量分别增加了1.26~2.42和1.00~1.72 t/hm^(2)。与I_(AWD)Z_(0)相比,I_(AWD)Z_(10)处理地上部干物质累积量在拔节孕穗期、抽穗开花期、乳熟期和成熟期分别增加了20.96%~31.24%、16.89%~30.44%、17.87%~25.45%和13.43%~21.12%,地上部氮累积量分别增加了19.92%~47.14%、14.90%~43.88%、21.68%~31.37%和7.18%~30.27%。I_(AWD)Z_(0)与I_(CF)Z_(0)处理土壤无机氮含量差异不显著,I_(AWD)Z_(10)处理土壤无机氮含量最高,较I_(AWD)Z_(0)处理增加了19.88%~40.96%。在分蘖—穗肥阶段,5年间I_(AWD)Z_(10)处理的土壤NH_(4)^(+)-N含量较I_(CF)Z_(0)和I_(AWD)Z_(0)处理分别增加了31.83%~48.84%和28.35%~52.80%。I_(AWD)Z_(0)和I_(CF)Z_(0)处理收获后土壤全氮含量差异不显著,I_(AWD)Z_(10)较I_(CF)Z_(0)处理显著提高了收获期土壤全氮含量,提升幅度为9.27%~11.41%,这表明随着时间的延长,斜发沸石并不会对土壤养分产生负面影响,反而对土壤养分具有长期改善的作用。【结论】在干湿交替灌溉条件下,一次性施用斜发沸石可连续多年提高水稻生育期土壤铵态氮含量、增加土壤全氮,进而促进水稻氮吸收,提高氮肥偏生产力和产量。因此,斜发沸石可用于新型灌溉技术下提高水稻产量,实现稻田可持续利用。 展开更多
关键词 斜发沸石 干湿交替灌溉 水稻 产量
下载PDF
干湿交替下黄土区苜蓿根系抗拔力学性能
14
作者 黄梦琦 张超波 +3 位作者 丁阳 张强 冯潇慧 蒋静 《水土保持研究》 CSCD 北大核心 2024年第1期214-223,共10页
[目的]研究黄土区干湿交替过程对草本植物根系抗拔力学性能的影响,以期为草本植物根系固土护坡工程提供一定的理论支持和依据。[方法]选取紫花苜蓿为研究对象,采用重塑土根系拉拔试验,研究苜蓿根系抗拔力学性能及其与根径、根长、土壤... [目的]研究黄土区干湿交替过程对草本植物根系抗拔力学性能的影响,以期为草本植物根系固土护坡工程提供一定的理论支持和依据。[方法]选取紫花苜蓿为研究对象,采用重塑土根系拉拔试验,研究苜蓿根系抗拔力学性能及其与根径、根长、土壤容重、干湿交替作用等影响因素的关系。[结果](1)苜蓿根系抗拔力学性能指标与根径、根长和土壤容重存在幂函数或指数函数关系。(2)相比未干湿交替试样,干湿交替试样根系抗拔力学性能指标均显著减小。(3)砂壤土中苜蓿根系抗拔力学性能指标均优于壤土,且干湿交替在砂壤土中对苜蓿根系抗拔力学性能指标的影响小于在壤土中的影响。(4)根径、根长及容重和干湿交替的耦合作用对根系抗拔力学性能指标有显著影响。[结论]在干湿交替作用下,根径、根长和土壤容重对苜蓿根系抗拔力学性能有一定影响。 展开更多
关键词 干湿交替 苜蓿根系 抗拔力学性能 耦合影响
下载PDF
基于日尺度旱涝急转指数的重庆市旱涝急转事件演变特征分析
15
作者 刘玉冰 刘波 +4 位作者 王文鹏 邱鹏 黎春蕾 仵新燕 刘缘晴 《水资源与水工程学报》 CSCD 北大核心 2024年第4期20-28,共9页
为准确地反映旱涝急转事件的“突发性”与“交替性”特征,对重庆市34个气象站采用日尺度旱涝急转指数DWAAI提取1960—2018年旱涝急转事件,根据重庆市的实际情况划分不同强度旱涝急转事件对应的DWAAI数值范围,探究不同强度旱涝急转事件... 为准确地反映旱涝急转事件的“突发性”与“交替性”特征,对重庆市34个气象站采用日尺度旱涝急转指数DWAAI提取1960—2018年旱涝急转事件,根据重庆市的实际情况划分不同强度旱涝急转事件对应的DWAAI数值范围,探究不同强度旱涝急转事件发生频次的时空演变特征。结果表明:重庆市旱涝急转事件以旱急转涝为主,旱急转涝事件占旱涝急转事件累计次数的85%,主要发生在4—9月,多年平均次数为22.64站次,其中,中度、重度事件占所有旱急转涝事件的11.7%、2.9%;旱急转涝事件频发于重庆市西部、中部及东北部区域,发生频次的变化趋势不显著;涝急转旱事件主要发生在7—9月,多年平均次数为5.60站次,轻度、中度事件占所有涝急转旱事件的92.9%、7.1%;涝急转旱事件在重庆市东南部、中部以及东北部区域的西部地区(如开县)频发,频发地区的发生频次总体呈增加的趋势。研究成果可为保障重庆市及相关地区水安全、加强防旱抗涝减灾工作提供理论基础。 展开更多
关键词 旱涝急转事件 日尺度旱涝急转指数 方差校正的Sen趋势检验 时空演变 重庆市
下载PDF
基于SVM算法的超声波速度-土壤含水率估计模型
16
作者 陈盈宜 潘丽敏 +2 位作者 叶勇 李君 黄光文 《华中农业大学学报》 CAS CSCD 北大核心 2024年第2期247-253,共7页
为快速准确获取土壤含水率信息,便于农业精准灌溉,引入支持向量机算法(SVM)对4种不同干湿交替处理下超声波速度与土壤含水率进行拟合分析和回归训练优化,构建基于超声波速度的土壤含水率预测模型。结果显示,与传统的烘干法相比较,利用... 为快速准确获取土壤含水率信息,便于农业精准灌溉,引入支持向量机算法(SVM)对4种不同干湿交替处理下超声波速度与土壤含水率进行拟合分析和回归训练优化,构建基于超声波速度的土壤含水率预测模型。结果显示,与传统的烘干法相比较,利用该模型在田间验证土壤含水率,平均相对误差为1.5%左右。研究结果表明,基于SVM模型构建的超声波速度-土壤含水率预测模型能够较好地描述被研究区域内土壤含水率,可为利用超声波特性实现对农田土壤水分的持续监测提供参考。 展开更多
关键词 土壤含水率 超声波速度 SVM算法 干湿交替
下载PDF
碳钢腐蚀大数据采集传感器在城市大气环境中适应性标定
17
作者 张帆 徐迪 +6 位作者 杨小佳 王一品 陈昊 彭非凡 安江峰 程学群 李晓刚 《中国表面工程》 EI CAS CSCD 北大核心 2024年第2期1-15,共15页
传统的腐蚀监测方法和腐蚀评估方法已经无法满足对数据量以及数据连续性的需要。大气腐蚀在线监测技术由于具有数据量大、数据连续及实时性等特点,已被广泛应用。然而,所得数据的准确性和适用性还须通过试验来做进一步验证。采用户外挂... 传统的腐蚀监测方法和腐蚀评估方法已经无法满足对数据量以及数据连续性的需要。大气腐蚀在线监测技术由于具有数据量大、数据连续及实时性等特点,已被广泛应用。然而,所得数据的准确性和适用性还须通过试验来做进一步验证。采用户外挂片以及电阻传感器和电偶传感器监测Q235碳钢在城市大气环境下的腐蚀速率,建立响应面模型,并采用温湿度耦合试验和干湿交替模拟试验进行验证。温湿度耦合试验和干湿交替模拟试验与户外挂片及响应面模型的腐蚀速率变化趋势一致,而温湿度耦合试验得到的腐蚀速率更接近于挂片得到的腐蚀速率。其中,电偶传感器得到的腐蚀速率值更接近于挂片的腐蚀速率值,说明城市大气环境下更适合使用电偶传感器。室内模拟试验中,温度升高会加速薄液膜下阴阳极的电极过程和化学反应,延长反应时间,表面腐蚀产物逐渐致密且均匀,一定程度上可以提高锈层的耐蚀性能。通过碳钢腐蚀传感器在城市大气环境中的适应性标定,可以深入探究大气环境中金属材料的腐蚀机理和过程,并准确评估腐蚀传感器在大气环境中的腐蚀行为,为研究者提供定量描述和分析腐蚀行为的基础数据。 展开更多
关键词 电阻传感器 电偶传感器 响应面模型 温湿度耦合试验 干湿交替模拟试验
下载PDF
稻米淀粉、蛋白质和脂质与蒸煮食味品质关系研究进展 被引量:1
18
作者 翁雪莲 姜丽秋 +5 位作者 唐树鹏 张伟杨 朱宽宇 王志琴 杨建昌 徐云姬 《华中农业大学学报》 CAS CSCD 北大核心 2024年第3期121-131,共11页
蒸煮食味品质是消费者选择稻米的重要评价标准。淀粉、蛋白质和脂质作为稻米的三大主要物质成分,与其蒸煮食味品质关系密切。为进一步探索稻米蒸煮食味品质形成机制及水稻优质栽培技术,本文综述了稻米三大主要物质的组成与分布、合成代... 蒸煮食味品质是消费者选择稻米的重要评价标准。淀粉、蛋白质和脂质作为稻米的三大主要物质成分,与其蒸煮食味品质关系密切。为进一步探索稻米蒸煮食味品质形成机制及水稻优质栽培技术,本文综述了稻米三大主要物质的组成与分布、合成代谢特点及其与蒸煮食味品质关系的研究进展,总结了干湿交替灌溉技术对稻米三大主要物质及其蒸煮食味品质的影响,并提出了研究存在三大主要物质互作与稻米蒸煮食味品质关系不清楚以及干湿交替灌溉对蒸煮食味品质的调控机制不明确等问题。建议今后基于淀粉、蛋白质和脂质累积与合成代谢的关系深入研究稻米蒸煮食味品质形成机制以及轻-干湿交替灌溉对稻米蒸煮食味品质的调优机制。 展开更多
关键词 稻米 蒸煮食味品质 淀粉 蛋白质 脂质 干湿交替灌溉
下载PDF
模拟干湿条件下土壤酶活性对坝地土壤有机碳矿化的影响
19
作者 邢欣然 张祎 +4 位作者 李鹏 刘晓君 陶清瑞 任正龑 胥世斌 《干旱区研究》 CSCD 北大核心 2024年第11期1969-1980,共12页
气候变化导致长期干旱和强降雨事件的发生频率增加,从而对生态系统碳循环产生影响。因此,了解不同干湿条件土壤酶活性如何影响有机碳矿化,能够帮助深入理解碳循环机制并推进全球碳中和目标达成。据此,本研究选择黄土高原特有的控制侵蚀... 气候变化导致长期干旱和强降雨事件的发生频率增加,从而对生态系统碳循环产生影响。因此,了解不同干湿条件土壤酶活性如何影响有机碳矿化,能够帮助深入理解碳循环机制并推进全球碳中和目标达成。据此,本研究选择黄土高原特有的控制侵蚀所修建的淤地坝为研究对象,并设计淹水胁迫、干旱胁迫和干湿循环3种处理监测土壤酶活性及有机碳矿化过程。结果表明:干湿循环对有机碳矿化存在瞬时激发效应,且有机碳累积矿化量介于干旱胁迫和淹水胁迫之间。同时干湿循环均会增加碳循环和氮循环相关酶活性,但随着循环次数的增加酶活性逐渐降低并趋于稳定。三种水分处理条件下酶活性均受到碳和磷的限制,而干湿循环次数越多碳限制越强烈,第四次干湿交替后干湿交替条件下磷限制作用超过淹水胁迫和干旱胁迫。当土壤处于干旱、淹水胁迫以及干湿循环时,限制有机碳矿化的酶活性因子也各不相同。干旱胁迫下磷酸酶因子的直接作用为99%,淹水胁迫下EAAC/N(碳循环相关酶/氮循环相关酶)和木糖苷酶因子的直接作用为87%,干旱胁迫和淹水胁迫下因子间交互作用仅为1%和13%。干湿循环条件下,磷酸酶和β-N-乙酰氨基葡萄糖苷酶因子的直接作用为75%,因子间交互作用为25%,干湿循环可以显著增加因子之间的相互联系。本研究可为明晰黄土高原淤地坝建设在国家碳中和目标中发挥的作用提供理论支撑。 展开更多
关键词 干湿交替 土壤酶 土壤有机碳矿化 黄土高原
下载PDF
干湿交替灌溉和生物质炭施用对稻田碳汇与甲烷排放的影响及其机理研究进展
20
作者 蔡炜 秦缘 +3 位作者 陈浩田 林晨语 杨建昌 张伟杨 《中国稻米》 北大核心 2024年第6期7-14,共8页
稻田系统作为重要的碳库,对全球碳排放具有十分重要的影响。灌溉方式和生物质炭的施用是影响水稻生长发育和稻田“碳汇与碳排”的关键措施。本文重点阐述了稻田甲烷排放机制、稻田土壤碳汇机制以及干湿交替灌溉和生物质炭施用对稻田“... 稻田系统作为重要的碳库,对全球碳排放具有十分重要的影响。灌溉方式和生物质炭的施用是影响水稻生长发育和稻田“碳汇与碳排”的关键措施。本文重点阐述了稻田甲烷排放机制、稻田土壤碳汇机制以及干湿交替灌溉和生物质炭施用对稻田“碳汇与碳排”的调控作用和机制。同时,对研究过程中发现的问题进行讨论,并对今后的研究方向进行了展望,以期为实现水稻高产高效生产与固碳减排协同提供理论依据。 展开更多
关键词 水稻 干湿交替灌溉 生物质炭 土壤碳汇 甲烷排放
下载PDF
上一页 1 2 16 下一页 到第
使用帮助 返回顶部