排序方式： 共有60条查询结果，搜索用时 22 毫秒
31.
林区TM图像消除噪声方法的比较 总被引：3，自引：0，他引：3
介绍了几种消除噪声滤波方法的数学基础,并结合吉林省汪清林业局数据,分别用低通滤波、统计滤波、增强型自适应滤波、均值平滑滤波、中值滤波方法对研究区TM遥感图像进行滤波消噪处理,并以平滑指数FI、边缘保持因素T和峰值信噪比PSNR为评价指标,对实验结果进行了对比分析,结果表明,统计滤波（D=1）和增强型自适应滤波用于林区TM图像消除噪声的滤波器中比较好。 相似文献
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ppk1 基因编码的多聚磷酸盐激酶主要负责多聚磷酸盐的合成,其表达量的高低直接决定聚磷菌的聚 P 能力的强弱.Pseudomonas putida GM6 是从 EBPR 好氧池活性污泥中分离获得的一株具有聚 P 能力的菌株,该菌株含有两个编码多聚磷酸盐激酶的基因(ppk1 和 ppk2).通过 PCR 从高效聚磷菌株总 DNA 中扩增得到了 ppk1 及其启动子,并定向克隆到 pBBRMCS-5 载体上,构建了重组质粒 pMEPE-PPK,在辅助质粒 pRK2013 的帮助下,通过三亲接合将 pMEPE-PPK 转移到原始菌株 GM6 中,获得的工程菌 P. putida GM6-PPK1.GM6-PPK1 除 P 能力较原始菌株 GM6 和对照菌株 GM6-P5 提高了 54%,生长能力较原始菌株也有一定增强.通过模拟 EBPR 工艺,发现 GM6-PPK1 在厌氧/好氧交替的环境条件下强化表达不但提高了菌体好氧段的吸 P 能力,而且厌氧段 P 的释放和 PHA 的合成较之原始菌株也有显著增加. 相似文献
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一种基于数字高程模型的流域边界提取修正方法 总被引：5，自引：0，他引：5
WANGDian-zhong HAOZhan-qing XIONGZai-ping 《林业研究》2004,15(4):283-286
Boundary extraction of watershed is an important step in forest landscape research. The boundary of the upriver watershed of the Hunhe River in the sub-alpine Qingyuan County of eastern Liaoning Province, China was extracted by digital elevation modeling (DEM) data in Arclnfo8.1. Remote sensing image of the corresponding region was applied to help modify its copy according to Enhanced Thematic Mapper (ETM) image‘s profuse geomorphological structure information. Both the DEM-dependent boundary and modified copy were overlapped with county map and drainage network map to visually check the effects of result. Overlap of county map suggested a nice extraction of the boundary line since the two layers matched precisely,which indicated the DEM-dependent boundary by program was effective and precise. Further upload of drainage network showed discrepancies between the boundary and the drainage network. Altogether, there were three sections of the extraction result that needed to correct. Compared with this extraction boundary, the modified boundary had a better match to the drainage network as well as to the county map. Comprehensive analysis demonstrated that the program extraction has generally fine precision in position and excels the digitized result by hand. The errors of the DEM-dependant extraction are due to the fact that it is difficult for program to recognize sections of complex landform especially altered by human activities, but these errors are discernable and adjustable because the spatial resolution of ETM image is less than that of DEM. This study result proved that application of remote sensing information could help obtain better result when DEM method is used in extraction of watershed boundary. 相似文献
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增铵营养对小麦早期生长的促进效应 总被引：10，自引：2，他引：8
应用水培试验的方法,研究了小麦在不同形态氮营养下（ＮＨ＾＋４／ＮＯ＾－３分别为０／１００、５０／５０和１００／０）的生长特征。与单一形态氮营养相比,增铵营养在五叶期显著增加了小麦植株的株高、叶干重和总干重;在７叶期,显著增加了小麦株高、单株分蘖数、叶面积、叶干重、茎鞘干重、地上部干重和总干重。与单一ＮＯ＾－３营养相比,单一ＮＨ＾＋４营养显著降低单株分蘖数、叶面积、叶干重、茎鞘干重、根干重、地上部干 相似文献
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Bacteria capable of utilising oxamyl as the sole carbon source were isolated from seven different agricultural soils that had previously demonstrated enhanced oxamyl degradation in a soil incubation study. Partial sequencing and alignment of the 16S rRNA gene showed little diversity amongst isolates, with 26 of the 27 isolates demonstrating similarity to the genus Aminobacter. The most common species isolated was Aminobacter aminovorans, while a number of the isolates demonstrated an equal degree of similarity to the species Aminobacter niigataensis and Chelatobacter heintzii. One isolate was identified as Mesorhizobium sp. This is the first time that organisms involved in the degradation of oxamyl have been isolated and identified. 相似文献
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蛋白质免疫印记技术是研究和分析蛋白质的重要手段,由于其步骤繁杂、影响因素众多,常出现背景噪音高、非特异条带多、拖尾等问题,严重影响后续蛋白质定量分析。为建立最佳的检测家兔动脉组织中蛋白质表达的蛋白质免疫印记技术实验条件,以家兔动脉组织血管细胞粘附分子-1为目标蛋白,从电泳条件、抗体浓度、抗体孵育时间、温度及方法、免疫显色方法等方面进行了改良,成功建立了快速、灵敏、特异的蛋白质免疫印记技术体系;并比较了3种常用的酶免疫显色技术：3,3’-二氨基联苯胺（3,3’-diaminobenzidine,DAB）显色、增强化学发光法（enhanced chemil luminescence,ECL）X光片曝光及ECL化学发光冷却电感耦合成像系统（cooled charged-coupled device,CCD）成像的敏感性。结果表明ECL化学发光法比DAB显色法敏感性高出2～10倍,其中CCD系统敏感性高于X光片4倍,且操作简便,是最理想的检测方法。 相似文献
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利用控制条件下的水培试验方法,研究了两种铵硝配比(NH4+/NO3-为100/0和75/25)营养条件对4种不同硝响应型水稻品种苗期根系生长的影响。结果表明,在增硝营养(NH4+/NO3-为75/25)条件下,不同水稻品种NO3-的反应差异明显。与全NH4+营养条件相比,增硝营养条件下对NO3-强响应的水稻品种南光的根系干重和氮积累量显著增加,增幅达50%和79%;同时南光的根系总根长、总不定根长和总侧根长增幅均达到显著水平;不定根数、新根数和侧根数亦显著增加;平均不定根长和平均侧根长差异不显著;对硝弱响应型的水稻品种上海97、辽粳和Elio在增硝营养培养下的根系不定根、新根和侧根的长度和数量差异均不显著。这表明增NO3-营养仅仅促进了对NO3-强响应型水稻南光根系的不定根和侧根的发生,进而促进根系对氮素的吸收,并没有促进不定根和侧根的伸长。从本试验的结果可推论,水稻根系对硝态氮的响应度强弱可能是水稻品种氮素效率差异性的因子之一。 相似文献
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本试验将研制的禽霍乱强化苗与Intervet疫苗进行免疫比较试验。结果表明强化苗在免疫早期抗体产生时间优于Intervet疫苗。免疫1个月后,两种疫苗试管凝集抗体效价曲线无明显差异,免疫期均达6个月。两种疫苗1至6个月的攻毒保护率分别为94. 4％和86. 7％。两种疫苗免疫接种产蛋鸡后2周内,分别使免疫鸡的平均日产蛋量下降2.6％和6.5％、以上试验表明,本课题组研制的禽霍乱强化苗在免疫性方面已经达到或部分指标已超过国际同类先进产品的水平。 相似文献
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