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941.
基于GIS的县域肥料配方设计   总被引:1,自引:0,他引:1  
以湖北省洪湖市为例,利用土壤养分丰缺指标法,结合运用了ArcGIS 9.0软件的地统计分析模块(Geostatistical Analyst) 空间分析模块(Spatial Analyst),研究了湖北省洪湖市中稻、棉花适宜的复混肥料配方及其在县域上的分布.结果表明,中稻、棉花适宜的复混肥料配方(N-P2O3-K2O比例)各3个,中稻配方为21%-6%-18%、20%-9%-16%、20%-11%-14%,棉花配方为19%-8%-18%、20%-9%-16%、21%-12%-12%.  相似文献   
942.
不同成熟度对红花大金元上部烟叶等级质量的影响   总被引:5,自引:0,他引:5  
运用完全随机设计,研究了不同采收成熟度对烤烟(Nicotiana tobacum L)品种红花大金元烤后烟叶等级质量的影响.结果表明,上等烟率、均价的平均值均为处理3>处理2>处理1>处理4,橘黄烟率的均值为处理3>处理2>处理4>处理1,杂色烟率的均值为处理1>处理4>处理2>处理3.综合考虑,从提高红花大金元上部烟叶上等烟率、橘黄烟率、均价以及减少杂色烟率的角度出发,处理3为适宜的采收成熟度.  相似文献   
943.
以黑河流域为区域背景,运用分形理论,定量化地研究西北干旱区景观镶嵌结构的复杂性与稳定性。研究结果表明:(1)各景观要素,按照镶嵌结构的复杂性程度(分维值D)排序,依次分别为:高山草原>河滩地绿洲>漫灌戈壁绿洲>高山寒漠>土质平地盐漠>土质平地荒漠>中山森林>低滩地绿洲>中山草原>高山草甸>草原化荒漠>河湖滩地盐漠>冰川和永久性积雪>平沙地沙漠>固定沙丘沙漠>低平滩地盐漠>人工绿洲>荒漠草原>居民点(城市)>荒漠戈壁>荒漠剥蚀戈壁>高山草甸沼泽>半固定沙丘沙漠>流动沙丘沙漠>丘陵山地荒漠>高山灌丛草甸>中山灌丛草原>中山草甸草原。(2)各景观要素,按照镶嵌结构的稳定性程度(SK)排序,依次分别为:高山草原>河滩地绿洲>中山草甸草原>中山灌丛草原>高山灌丛草甸>丘陵山地荒漠>漫灌戈壁绿洲>高山寒漠>流动沙丘沙漠>半固定沙丘沙漠>土质平地盐漠>土质平地荒漠>中山森林>低滩地绿洲>高山草甸沼泽>中山草原>荒漠剥蚀戈壁>高山草甸>荒漠戈壁>居民点(城市)>荒漠草原>草原化荒漠>人工绿洲>低平滩地盐漠>固定沙丘沙漠>平沙地沙漠>河湖滩地盐漠>冰川和永久性积雪。(3)在各景观要素的镶嵌结构中,高山草原是最复杂,同时也是最稳定的;自然绿洲的复杂性和稳定性都大于人工绿洲。镶嵌结构最为简单的是中山草甸草原。最不稳定的景观要素,恰恰就是维系绿洲生存的关键-冰川和永久性积雪。(4)在沙漠和荒漠化景观中,固定沙丘和平沙地沙漠的复杂性虽然高于半固定沙丘、流动沙丘、荒漠戈壁、荒漠剥蚀及壁及荒漠草原,但是其稳定性却低于半固定沙丘、流动沙丘、荒漠戈壁、荒漠剥蚀戈壁、荒漠草原及草原化荒漠。这就是说,固定沙丘并不稳定。(5)在草原景观中,荒漠草原的稳定性最差。  相似文献   
944.
PCR用于鸭瘟病毒诊断的研究   总被引:3,自引:0,他引:3  
根据鸭瘟病毒UL6和UL7基因序列,设计合成了一对引物,以2株疫苗株、1株强毒株和1株山东分离株DNA为模板,进行PCR扩增,得到预期690bp的目的片段.将扩增的目的片段克隆到pMD18-T载体,经Amp平板筛选,HindⅢ、BamHⅠ双酶切鉴定,获得阳性重组质粒.对重组质粒进行序列测定,与参考序列比较,山东分离株与参考序列的同源性为99.7%,其余3株DPV与参考序列的同源性均为100%.应用PCR可检测人工感染和自然感染鸭瘟的组织中的鸭瘟病毒,表明PCR检测鸭瘟病毒具有很高的特异性、敏感性,该法能够用于鸭瘟急性及亚临床感染的检测与诊断.  相似文献   
945.
AIM: To observe the changes in proliferation and apoptosis of macrophages in the development of pulmonary fibrosis in rats. METHODS: The number of macrophages, apoptotic cells, the proliferation index (PI) and MTT activity of macrophages were assayed on the day 14 and the day 30 after intratracheal adminstration BLMA5 in rats. RESULTS: (1) The number of alveolar macrophages was increased in BLMA5 14 d group and in BLMA5 30 d group, compared with sham 14 d group and sham 30 d group, respectively. The number of macrophages in BLMA5 14 d group was higher than that in BLMA5 30 d group. (2) The PI of macrophages increased in BLMA5 14 d group, and decreased in BLMA5 30 d group. (3) The number of apoptotic cells increased both in BLMA5 14 d group and BLMA5 30 d group. The number of apoptotic cells in BLMA5 14 d group was lower than that in BLMA5 30 d group. (4) The MTT activity of macrophages was higher in BLMA5 14 d group and in BLMA5 30 d group than that in sham 14 d group and sham 30 d group, respectively. CONCLUSIONS: The ability of proliferation increased at first, and then decreased, but the apoptosis of macrophages increased all the time, in the development of pulmonary fibrosis. This might be partly contributed to the changes of the number and function of macrophages in lung.  相似文献   
946.
内蒙古高原荒漠化治理途径的探讨   总被引:6,自引:1,他引:6  
在总结历史和现今人们治理荒漠化丰富经验及研究成果的基础上,通过亲身实践和科学观测认为,只要加强国际、国内间紧密合作,牢固树立科学发展观,通过依法治理、工程治理、科学治理、产业结构调整、退耕退牧还林还草5个途径,内蒙古高原的荒漠化是可以得到缓解和治理的.  相似文献   
947.
以语篇重建任务为中心的整体语言教学模式是为克服传统的以传授语言知识为中心的零碎语言教学模式存在的问题而提出的;该模式不仅把英语视为语言知识的载体,更将其视为信息的载体.教师通过任务的提出为先导,以小组为单位组织学生参与围 绕语篇解构和重建的听说读写方面的活动,使学生不断地运用目的语获取信息和表达信息,从而产生综合效应,推动语言能力的全面发展.  相似文献   
948.
OBJECTIVE: To determine effects of oral administration of metronidazole on the number and species of duodenal bacteria and selective nutrients of cats. ANIMALS: 6 healthy domestic shorthair cats. PROCEDURE: Undiluted duodenal fluid was obtained for quantitative and qualitative bacterial culture to determine species and number of bacteria in healthy cats. Blood samples were assayed for taurine, total protein, albumin, cobalamin, and folate concentrations. Cats then were given metronidazole (20 mg/kg of body weight, PO, q 12 h) for 1 month, after which bacterial cultures and serum assays of nutrients were repeated. Nine months after cessation of antibiotic treatment, duodenal bacteria were re-evaluated and serum was assayed for total protein, albumin, cobalamin, and folate concentrations. RESULTS: Oral administration of metronidazole caused a significant decrease in aerobic and anaerobic bacterial counts in the duodenum of healthy cats, accompanied by emergence of Streptococcus spp and Corynebacterium spp. Serum concentrations of cobalamin and albumin increased when duodenal bacterial counts were decreased, although changes in folate or taurine concentrations were not detected. Measured variables did not differ, when comparing results obtained before and 9 months after cessation of metronidazole. CONCLUSIONS AND CLINICAL RELEVANCE: Oral administration of metronidazole decreased the number of aerobic bacteria and altered indigenous flora in the small bowel of cats. Normal duodenal flora appeared to be stable, because species of bacteria were re-established by 9 months after cessation of metronidazole. Bacterial flora appeared to have an impact on nutrients, because albumin and cobalamin increased during antibiotic administration and returned to preadministration concentrations after cessation of the antimicrobial.  相似文献   
949.
A 4-year-old Basque Shepherd male dog was presented for breeding soundness evaluation after the dog failed to impregnate the three bitches he had mated. Clinical examination showed no anomaly of the reproductive system. Semen evaluation showed normal sperm count (640 x 10(6)), 80% had progressively motile spermatozoa, and 96% had morphologically abnormal sperm of which 84% had proximal cytoplasmic droplet and 12% had proximal droplet plus other anomaly. A zona pellucida-binding assay, using canine oocytes derived from frozen-thawed ovaries, was performed in order to investigate the zona-binding ability of dog spermatozoa with proximal cytoplasmic droplets. For the zona pellucida-binding assay, ovaries were thawed and minced in phosphate-buffered saline + 0.4% bovine serum albumin, the oocytes recovered were divided into two groups of 35-40 oocytes to be, respectively, used with the infertile dog and with a control fertile dog. Spermatozoa were capacitated in Canine Capacitating Medium (CCM) at 38.5 degrees C and 5% CO(2) in air for 2 h before oocyte insemination. Groups of five to six oocytes placed in 45 microl droplets of CCM were incubated for 1 h. Afterwards, 5 microl of CCM containing 25,000 spermatozoa were added to each droplet and co-incubated for 2 h before fixation and evaluation of the complexes. After oocyte insemination, sperm motility and viability were evaluated: the sample from the infertile dog had 85% sperm motility with fast and linear progressive movement, and sperm viability of 92%. The sample from the control dog showed 40% sperm motility with fast and highly curvilinear and erratic movement, high degree of sperm agglutination and sperm viability of 32%. For the infertile dog the mean number of bound spermatozoa/oocyte was 0.33 whereas for the control dog it was 1.80. It was concluded that dog sperm with proximal cytoplasmic droplets seem to lack normal capacitating ability in vitro, and consequently, they may have reduced capacity to bind to the zona pellucida of canine oocytes.  相似文献   
950.
从潜伏期感染马立克氏病病毒(MDV)鸡淋巴组织中提取基因组DNA,采用梯度PCR的方法获得MDV的L—meq、meq基因,将其插入pMD18-T克隆载体,经测序并进行了序列分析。结果表明,L—meq、meq基因同源性很高,L—meq中只有180bp与meq不同。但是采用同样的方法在发病期病鸡淋巴组织中却只能获得MDV的meq基因。为了进一步研究发病期L—meq基因消失的原因,试验对L—meq、meq基因的氨基酸序列的结构域进行了分析。结果表明,L—meq基因中含有9个PRR(proline—rich—reapts)区域,meq中含有6个PRR区域,从而推断PRR区域可能与基因的转录激活及调控病毒DNA复制的功能有关。该180bp插入序列也许能解释初期感染MDV不致瘤的原因,同时也意味着L—meq基因对于潜伏期的维持是必要的。  相似文献   
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