检索结果-南通市图书馆

在线全文

学校读者我要写书评

暂无评论

稻草还田对晚稻稻田甲烷排放的影响

土壤学报 2002年第2期39卷 170-176页

作者：陈苇卢婉芳段彬伍 wassmann r Lantin rS 中国水稻研究所杭州310006 国际水稻研究所

晚稻稻田的甲烷排放呈现前高后低特点 ,稻田甲烷的日排放速率与日均气温具有良好的正相关。稻草翻施使稻田甲烷排放量上升 5 1 .1 1 % ,而采用稻草表施的方法甲烷排放量仅增加 33.98%。水稻分蘖期是稻田甲烷排放的重要时期 ,其甲烷排放... 详细信息

晚稻稻田的甲烷排放呈现前高后低特点 ,稻田甲烷的日排放速率与日均气温具有良好的正相关。稻草翻施使稻田甲烷排放量上升 5 1 .1 1 % ,而采用稻草表施的方法甲烷排放量仅增加 33.98%。水稻分蘖期是稻田甲烷排放的重要时期 ,其甲烷排放量占水稻全生育期排放总量的 65 .6% ,施用稻草进一步加大水稻分蘖期的甲烷排放比例。与稻草翻施相比 ,稻草表施的甲烷减排突出表现在水稻分蘖期及一天中 1 2∶0 0～ 1 6∶0 0的甲烷排放高峰时段。土壤 5cm处温度的昼夜周期性变化与稻田甲烷排放的昼夜周期性变化具有高度相关性。

关键词：水稻稻草还田甲烷排放土壤水溶解温室气体大气污染

MODEL FOr ESTIMATE METHANE EMISSIONS FrOM DrAINAGE IrrIGATED rICE FIELDS

在线全文

学校读者我要写书评

暂无评论

MODEL FOR ESTIMATE METHANE EMISSIONS FROM DRAINAGE IRRIGATED...

第三届国际甲烷与氧化亚氮减排技术大会

作者： K.Smakgahn S.Poonkaew S.Towprayoon r.L.Sass G.Gale r.wassmann A.Chidthaisong Joint Graduate School of Energy and Environment King Mongkut's University of Technology Thonburi School of Energy and Materials King Mongkut's University of Technology Thonburi Department of Ecology and Evolutionary Biology Rice University School of Bioresources King Mongkut's University of Technology Thonburi Institute for Meteorology and Climate research(IMK 4) Forschungszentrum Karlsruhe

Water management is the major important factor affected on rice production as well as on methane production from flooded rice *** the basis of available information on rice cultivation,removing floodwater induces aeration to the rice field soil and therefore inhibits methane production by ethnogeny,which leads to reduction of methane *** estimate methane emission from irrigation rice fields,model implementation is ***,the accuracy of estimation should be *** this study we focused on the effects of field drainage on methane emissions by using empirical *** hypothesis of the model,with the influence on soil redox potential（Eh）to methane emissions,based on Eh change during cultivation and draining interval which other field properties such as soil pH,soil temperature during draining period were *** exiting empirical model to estimates methane emissions has been modified according to field observations in irrigated cultivation area in *** data from a single rice-growing season in native rice field without organic fertilizer application was used to validate the *** results also compared with data from rice field in *** is noted that model shown acceptable confine patterns of methane emission with the draining activities in the fields.

关键词：

来源： cnki会议评论

在线全文

cnki会议

学校读者我要写书评

暂无评论

华中稻田甲烷排放的施肥效应及施肥策略

中国农业气象 1995年第2期16卷 1-5页

作者：王明星上官行健沈壬兴王跃思 r.wassmann H.renenberg W.Seiler 谢小立王卫东中国科学院大气物理研究所德国大琅和费大气环境研究所中国科学院长沙农业现代化研究所

研究了实施几种不同比例有阶肥及化肥的施肥方案对稻田甲烷排放的影响。在维持氮、磷、钾含量其本不变时，施较多的有机肥是甲烷排放率高的重要原因，而施较多化肥则能降低甲烷排放；同样是有机肥，已在沼气池中发酵后的沼渣经干燥后对... 详细信息

研究了实施几种不同比例有阶肥及化肥的施肥方案对稻田甲烷排放的影响。在维持氮、磷、钾含量其本不变时，施较多的有机肥是甲烷排放率高的重要原因，而施较多化肥则能降低甲烷排放；同样是有机肥，已在沼气池中发酵后的沼渣经干燥后对稻田甲烷徘放的正效应要大大低于“新鲜”有机肥；有机肥数量及性质的改变对甲烷排放的影响程度要远远大于改变化肥量对甲烷排放的影响，即有机肥的数量及性质显影响稻田甲烷排放的主要因素；控制甲烷排放的方法应重点放在控制有机肥的施用上，沼渣作为一种再生性的资源，具有多种优点，能够用来代替目前常用的有机肥。沼渣肥与化肥结合施用可能是降低稻田甲烷排放的有效措施。

关键词：稻田甲烷排放施肥控制

在线全文

学校读者我要写书评

暂无评论

我国华中地区稻田甲烷排放特征

大气科学 1994年第3期18卷 358-365页

作者：上官行健王明星沈壬兴王跃思 r.wassmann H.rennenberg W.Seiler 谢小立王卫东谢克和中国科学院大气物理研究所北京100029 德国夫朗和费大气环境研究所中国科学院长沙农业现代化研究所

本文主要讨论地处我国华中水稻生态区的湖南红壤稻田的CH4排放特征．稻田CH4排放的日变化都有一致的规律，即在下午16：00左右出现最大值；CH4排放的日变化幅度与天气条件和水稻植物体有关；CH4排放的日变化与温度日变化的相关性很好（r... 详细信息

本文主要讨论地处我国华中水稻生态区的湖南红壤稻田的CH4排放特征．稻田CH4排放的日变化都有一致的规律，即在下午16：00左右出现最大值；CH4排放的日变化幅度与天气条件和水稻植物体有关；CH4排放的日变化与温度日变化的相关性很好（r＞0．90）。早稻和晚稻的CH4排放季节变化规律有明显的差别，这主要是由于早、晚稻水稻生长期间的天气特别是空气温度变化的差异引起的，早稻CH4排放车在水稻生长中期（6月）略大，而晚稻在水稻移栽后几天内CH。排放就达到整个季节中的最大值，以后随时间逐渐降低；缺水会使CH4排放率明显降低，而且在重新灌水后相当长时间内CH4排放率没有回升；CH4排放在全有机肥的田中最大，然后依次是常规施肥、全语渣肥及化肥田；尿素、氯化钾和复合肥的多施可降低稻田CH。排放率；不同施肥田中CH4排放串的温度效应不同；施肥是控制CH4排放的一种可行手段；在整个晚稻生长季节中瞬时CH4排放率与瞬时温度呈明显的指数关系；在1991年双季水稻生长季节中，稻田中CH4的排放量为67．96gm－2，其中早稻的CH4排放率为0．36gm-2d－1，晚稻为0.

关键词：甲烷排放日变化温度施肥稻田

在线全文

学校读者我要写书评

暂无评论

猪粪与沼气渣对双季稻田甲烷排放的影响

生态学报 2001年第2期21卷 265-270页

作者：陈苇卢婉芳段彬伍 wassmann r Lantin r S 中国水稻研究所杭州310006 国际水稻研究所

随着环境温度的升高 ,稻田甲烷排放通量增加。早稻期间甲烷排放通量随着水稻生育期的增加而逐步加快 ,而晚稻甲烷排放主要集中在水稻生长的前中期 ,而且排放量很高。一天中甲烷排放具有很强的周期性 ,在 6:0 0～ 8:0 0时 ,甲烷排放通量... 详细信息

随着环境温度的升高 ,稻田甲烷排放通量增加。早稻期间甲烷排放通量随着水稻生育期的增加而逐步加快 ,而晚稻甲烷排放主要集中在水稻生长的前中期 ,而且排放量很高。一天中甲烷排放具有很强的周期性 ,在 6:0 0～ 8:0 0时 ,甲烷排放通量进入谷底 ,1 4 :0 0时甲烷排放通量达到峰值。稻田甲烷排放通量与土壤 5cm处的温度及土壤水溶解甲烷含量具有较高的相关性。猪粪和沼气渣的施用分别提高稻田甲烷排放量 2 2 .1 4 %和 4 .4 0 %。在早稻期间 ,施用猪粪和沼气渣分别提高土壤水溶解甲烷含量 4 0 .3%和 1 1 .9% ,而晚稻期间仅分别提高 2 3.9%和 5.0 4 %。

关键词：稻田甲烷排放溶解甲烷猪粪沼气渣

在线全文

学校读者我要写书评

暂无评论

稻田CH_4排放及控制技术的研究(英文)

作物学报 2001年第6期27卷 757-768页

作者：王增远徐雨昌李震过益先 r wassmann H U Neue r S Lantin L V Buendia 中国农业科学院作物育种栽培研究所北京100081 菲律宾国际水稻研究所

为了探索北方稻田水管理、施肥和水稻品种对稻田甲烷排放的影响 ,于 1995年至 1998年应用全自动甲烷采样 -测定系统 ,测定了水稻田甲烷排放通量。实验探明 :北方稻田甲烷排放通量为 4～364mg/m2 .d,平均值为 82 mg/m2 .d;稻田甲烷的季... 详细信息

为了探索北方稻田水管理、施肥和水稻品种对稻田甲烷排放的影响 ,于 1995年至 1998年应用全自动甲烷采样 -测定系统 ,测定了水稻田甲烷排放通量。实验探明 :北方稻田甲烷排放通量为 4～364mg/m2 .d,平均值为 82 mg/m2 .d;稻田甲烷的季节排放只有一个高峰 ,发生在水稻分蘖期 ,该期的甲烷排放量占年排放总量的 85 %以上 ,水稻生长中、后期的稻田甲烷非常有限。水管理对稻田甲烷的生成、排放有显著的影响 ,稻田采用间歇灌溉代替常规灌溉和淹灌 ,可减排稻田甲烷 4 6%～ 5 9% ;稻田施用有机肥 ,甲烷排放量则剧增。但在同等有机碳含量情况下 ,不同有机肥的产甲烷潜势存在明显差异 ,猪粪和稻草较高 ,堆肥和牛粪较低 ,稻田施用堆肥和牛粪 ,可比施用猪粪和稻草的稻田减排稻田甲烷 72 %～ 90 % ;试验中选用的水稻品种 ,以中作 93的甲烷排放效率为最低 ,其甲烷排放通量比杂交稻京优和高秆品种中花 94 - 10 17减少 5 0 %～ 5 5 %。实验揭示 ,水稻分蘖期是控制北方稻田甲烷排放的关键时期。

关键词：甲烷排放通量水稻田水管理水稻品种有机肥

Analysis and Optimization of Operational and Pollutant Attributes of Diesel Engine with CNT-Infused Orange Peel Biodiesel-Diesel Blend Fuel

在线全文

学校读者我要写书评

暂无评论

Journal of Thermal Science 2024年第2期33卷 761-778页

作者： ranjeet rAI r.r.SAHOO Mechanical Engineering Department GLA UniversityMathura281406India Mechanical Engineering Department IIT(BHU)Varanasi221005India

The current study is performed to find sustainable solutions for the future of transportation and environmental *** conventional methods and experimental design table(L16 Orthogonal Array)techniques have been employed to examine and optimize a diesel-powered engine's operational and pollutant *** L16 Orthogonal Array is obtained through Taguchi's experimental design approach using Minitab 16 *** experimental design incorporated three control variables,namely engine speed,fuel type,and engine load,each with four *** operational parameters,namely brake thermal efficiency(BTE)and brake specific fuel consumption(BSFC),as well as the emission characteristics,including hydrocarbon(HC),carbon monoxide(CO),nitrogen oxide(NO),and smoke emissions,were acquired using the L16 orthogonal array(OA) and subsequently *** utilization of methodologies such as signal-to-noise(S/N) ratio and grey analysis was employed to determine the optimal operational state of the engine to achieve maximum performance while minimizing *** engine's ideal state of operation,in terms of BTE and BSFC,was determined to be at 75% engine load,1000 r/min engine speed,and using 10^(-4)(in vol) carbon nanotube incorporated 20% orange peel biodiesel(OPB20CNT100) blended fuel(A3-B1-C4).The study indicated that engine load significantly influenced BTE and BSFC,with 84.05% and 87.79% contribution factors,*** 25% engine load,1000 r/min,and OPB20CNT100 fuel(A1-B1-C4) CO,smoke,NO,and HC emissions were the *** load affects emissions the *** BSFC increased 3.10% and NO emissions 1.77%.BTE,CO,smoke,and HC emissions decreased by 1.9%,12.29%,47.05%,and 47.22%,respectively,at optimal operating conditions concerning diesel *** study shows that Taguchi-Grey's experimental design optimizes diesel engine operational and pollutant *** outcomes revealed that orange peel biodiesel infused with CNT can replace diesel fuel in a

关键词： Taguchi-Grey method OPB20CNT100 transesterification S/N ratio GrG HC CO and NO

Multidimensional images and aberrations in STEM

在线全文

学校读者我要写书评

暂无评论

Chinese Physics B 2024年第9期33卷 68-74页

作者： Eric r.Hoglund Andrew r.Lupini Center for Nanophase Materials Sciences Oak Ridge National LaboratoryOak RidgeTN 37831United States

recent advances in scanning transmission electron microscopy(STEM)have led to increased development of multidimensional STEM imaging modalities and novel image reconstruction *** interest arises because the main electron lens in a modern transmission electron microscope usually has a diffraction-space information limit that is significantly better than the real-space resolution of the same *** state-of-affairs is sometimes shared by other scattering methods in modern physics and contributes to a broader excitement surrounding multidimensional techniques that scan a probe while recording diffraction-space images,such as ptychography and scanning nano-beam ***,the contrasting resolution in the two spaces raises the question as to what is limiting their effective ***,we examine this paradox by considering the effects of aberrations in both image and diffraction planes,and likewise separate the contributions of pre-and post-sample *** consideration provides insight into aberration-measurement techniques and might also indicate improvements for super-resolution techniques.

关键词： scanning transmission electron microscopy (STEM) aberrations

Kinematic analysis of flexible bipedal robotic systems

在线全文

学校读者我要写书评

暂无评论

Applied Mathematics and Mechanics(English Edition) 2024年第5期45卷 795-818页

作者： r.FAZEL A.M.SHAFEI S.r.NEKOO Department of Mechanical Engineering Shahid Bahonar University of KermanKerman ***Iran Departamento de Ingenieria de Sistemas y Automatica Escuela Técnica Superior de IngenieriaUniversidad de SevillaSeville 41092Spain

In spite of its intrinsic complexities,the passive gait of bipedal robots on a sloping ramp is a subject of interest for numerous *** distinguishes the present research from similar works is the consideration of flexibility in the constituent links of this type of robotic *** is not a far-fetched assumption because in the transient(impact)phase,due to the impulsive forces which are applied to the system,the likelihood of exciting the vibration modes increases ***,the human leg bones that are involved in walking are supported by viscoelastic muscles and ***,for achieving more exact results,it is essential to model the robot links with viscoelastic *** this end,the Gibbs-Appell formulation and Newton's kinematic impact law are used to derive the most general form of the system's dynamic equations in the swing and transient phases of *** most important issue in the passive walking motion of bipedal robots is the determination of the initial robot configuration with which the system could accomplish a periodic and stable gait solely under the effect of gravitational *** extremely unstable nature of the system studied in this paper and the vibrations caused by the impulsive forces induced by the impact of robot feet with the inclined surface are some of the very serious challenges encountered for achieving the above-mentioned *** overcome such challenges,an innovative method that uses a combination of the linearized equations of motion in the swing phase and the algebraic motion equations in the transition phase is presented in this paper to obtain an eigenvalue *** solving this problem,the suitable initial conditions that are necessary for the passive gait of this bipedal robot on a sloping surface are *** effects of the characteristic parameters of elastic links including the modulus of elasticity and the Kelvin-Voigt coefficient on the walking stability of this type of

关键词： bipedal robot flexible link swing phase transient phase eigenvalue problem Kelvin-Voigt coefficient