基于耕地连片度的高标准基本农田建设划区   总被引：6，自引：0，他引：6  

杨建宇  赵龙  徐凡  岳彦利  杜贞荣  朱德海 《农业机械学报》2017,48(4):142-148

为提高高标准基本农田划定区域的耕地连片性,在耕地综合质量评价和耕地连片网络基础上,提出了局部耕地连片度计算公式来评价耕地的连片性,并采用四象限法空间耦合耕地质量和连片度2个时空属性。结果表明:献县高标准基本农田优先建设区域面积为24 803.45 hm~2,重点建设区域面积为19 688.77 hm~2,有条件建设区域面积为19 538.64 hm~2,与面积累加方法相比,优先建设区域连片度提高了15.55%,而有条件建设区域连片度减小了37.82%,表明该方法明显提高了高标准基本农田建设划区的耕地连片度。  相似文献   

型如a^n-1或a^n＋1（n∈N＋）的标准分解式     

林舜婷 《张家口农专学报》2009,(5):8-10,14

探讨常见的型如a^n-1或a^n＋1（h∈N＋）的标准分解式．利用算术基本定理，对整数进行分解质因数是解决初等数论问题的重要途径．分解质因数的最基本方法是查质数表，但对于型如a^n-1或a^n＋1（n∈N＋）的数一般较大，要按此方法将其写成标准分解式并非易事，我们可以通过利用欧拉定理及同余性质探讨对这类数进行分解质因数的捷径．通过探讨研究得出解决此类数的标准分解式的两个定理，并推导型如2^n-1，2^2n＋1，2^3k＋1等特殊类型数的质因数的问题．利用得出的定理和推论对解决初等数论中的相关问题有着一定的意义．  相似文献   

Cytotoxicity of Senecio in macrophages is mediated via its induction of oxidative stress     

Samiran Bandyopadhyay  Goutam Mandal  Piu Saha  Mihir Sarkar 《Research in veterinary science》2009,87(1):85-90

In Arunachal Pradesh and other sub-Himalayan areas of India, accidental consumption of Senecio plants by yaks is often fatal as the plant contains toxic alkaloids like Seneciophylline. The present investigation was undertaken to demonstrate the pro-oxidant effects of an ethanolic extract of Seneciochrysanthemoides (S-EtOH). S-EtOH impaired viability in macrophages, the IC₅₀ being 13.8 ± 1.11 μg/mL. The effect of S-EtOH (1 μg/mL) on generation of reactive oxygen species (ROS) in macrophages was measured by flow cytometry using 2&prime;,7&prime;-dichlorofluorescein diacetate (H₂DCFDA) where it caused a significant increase in the mean fluorescence channel (MFC) from 8.55 ± 0.03 to 47.32 ± 2.25 (p < 0.001). S-EtOH also effected a 3.8-fold increase in extracellular nitric oxide (NO) generation from 4.90 ± 0.72 μM to 18.79 ± 0.32 μM (p < 0.001), a 2.2-fold increase in intracellular NO production, the MFC increasing from 14.95 ± 0.48 to 33.34 ± 1.66 (p < 0.001), and concomitantly depleted non protein thiols as analyzed by flow cytometry using mercury orange, with a reduction in MFC from 632.5 ± 49.44 to 407.4 ± 12.61 (p < 0.01). Additionally, S-EtOH (14 μg/mL, 24 h) caused apoptosis as evident by increased Annexin V binding and terminal deoxynucleotidyl transferase mediated dUTP DNA nick end labeling. Taken together, the cytotoxicity of S-EtOH can be partly attributed to its capacity to inflict oxidative damage via generation of both reactive oxygen and nitrogen species culminating in apoptosis.  相似文献   

Profiling of isoflavonoids in Iris germanica rhizome extracts by microprobe NMR and HPLC-PDA-MS analysis     

Schütz C  Quitschau M  Hamburger M  Potterat O 《Fitoterapia》2011,82(7):1021-1026

Lipophilic and polar extracts of iris rhizomes (Iris germanica) were submitted to a phytochemical profiling by a combination of HPLC–PDA–MS and semi-preparative HPLC/off-line microprobe NMR measurements. A total of 20 compounds were purified in sub-milligram to milligram amounts via two successive chromatographic steps. They were identified as isoflavones, isoflavone glycosides and acetovanillone by analysis of on-line MS and PDA, and off-line NMR data. A new isoflavone glycoside, iriflogenin-4&prime;-O-gentiobioside, was subsequently isolated at preparative scale for full chemical characterization. This study demonstrates the applicability of the HPLC/off-line microprobe NMR approach as a robust means for rapid phytochemical profiling of plant extracts.  相似文献   

Avine种鸡内脏器官发育的相关性研究     

秦豪荣  吉俊玲  王利兵 《黑龙江畜牧兽医》2003,(12):15-16

试验对Avine种母鸡育成期(5～25w)14个内脏器官进行了解剖观测，通过聚类分析和主成分分析，以研究内脏器官发育的相关性，从而为种鸡饲养管理和调控性成熟提供试验依据。结果表明：除腔上囊以外，各器官发育均为正相关，卵巢与其他器官呈中等正相关；卵巢和腔上囊各为一类，其他器官聚为一类；主成分分析表明卵巢的发育与腔上囊有抑制作用。  相似文献   

与Chevalley群F4(2)有关的几乎单群的OD-刻画     

晏燕雄 《西南大学学报(自然科学版)》2011,33(4)

利用有限群的群阶和度数型,对与Chevalley群F4(2)有关的几乎单群进行了刻画.得到了:Aut(F4(2))为OD-刻画;2.F4(2)为2-重OD-刻画.  相似文献   

素数阶射影平面的一种构造法     

阙树福 《福建林学院学报》1996,16(4):346-348

本文通过初等数论知识和关联矩阵的定义给出一类对称设计的设计方案，从而得到素数阶射影平面的一种构造法．  相似文献   

Sucrose synthase dominates carbohydrate metabolism and relative growth rate in growing kiwifruit (Actinidia deliciosa, cv Hayward)     

Stefano Moscatello  Franco Famiani  Simona Proietti  Daniela Farinelli  Alberto Battistelli 《Scientia Horticulturae》2011

Changes in fruit growth rate, carbohydrate content (glucose, fructose, sucrose and starch) and enzyme activity (sucrose synthase, UDPglucose pyrophosphorylase, fructokinase, glucokinase, sucrose phosphate synthase, ADPglucose pyrophosphorylase and invertases), in the external pericarp of kiwifruit, were measured throughout the growing season. Sucrose synthase showed the highest activity among the sucrose cleaving enzymes during large part of the growing season. The activity of invertases were much lower than that of sucrose synthase until ripening started. Sucrose synthase showed a tight although not linear relationship with the fruit RGR. Furthermore, sucrose synthase showed linear and significant correlations with the activities of both fructokinase and UDPglucose pyrophosphorylase indicating a strong co-regulation of the activities of these three enzymes involved in sucrose cleavage and sink strength, in kiwifruit. Sucrose synthase is suggested to be the dominating enzyme in the cleavage of imported carbon in kiwifruit, in tight coordination with fructokinase and UDPglucose pyrophosphorylase.  相似文献   

基本农田保护区划定的计算机辅助系统设计     

程锋  石英  朱德举 《农业网络信息》2002,17(5):5-7

为实现基本农田保护区划定的自动化,本文根据基本农田保护区划定工作的内容及程序,确定基本农田保护区划定系统的设计思路,在此基础上,对系统数据库设计以及系统功能模块设计进行了较为详细地论述。  相似文献   

单列模与拓扑模     

张国印 《金陵科技学院学报》2006,22(2):1-4

设R是任意带单位元的结合环,M是右R-模,如果Specr(M)构成一个Zariski拓扑,则称M是拓扑模,任意乘法模是拓扑模,任意单列模是拓扑模。如果R单环,则右R-模M是拓扑模当且仅当它是单列模。此外,几个熟知的乘法模的结果被推广到拓扑模上。  相似文献