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11.
张北县1∶1万大比例尺土地利用遥感调查的试验研究 总被引：6，自引：1，他引：6
基于SPOT-5 2.5 m高分辨率遥感影像等数据资料,该文探讨了开展大比例尺土地利用遥感调查的技术路线,进行了张北县大比例尺土地利用遥感调查的试验研究.调查结果表明:2002年张北县土地总面积为424 425.36 hm2,共包括37种土地利用类型,总图斑数是57 193个.其中,旱地、天然草地和有林地分别占全县土地总面积的43.77%、26.31%和7.76%,是该县的主要土地利用类型.与同期1:5万土地利用调查相比,1:1万大比例尺土地利用调查得到的结果更为精确,得到了荒草地、裸土地、裸岩石砾地和苇地等在1:5万土地利用调查中所不能表达的零碎图斑,说明与以往调查相比,该调查结果可以为土地管理决策和进一步的科学研究提供更为准确的信息支持,证明该文设计的应用高分辨率遥感影像进行1:1万土地利用调查的技术路线是正确的,对于今后类似的土地利用调查具有一定的指导意义.但是,通过该试验研究得知,目前试行的<全国土地分类>还不甚完善,为满足大比例尺土地利用遥感调查的要求,<全国土地分类>仍须进一步修订. 相似文献
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运用文献资料、访谈、数理统计等研究方法,对高中体育与健康课男生1 000米、女生800米数量累计评分法进行了实证研究,结果表明：数量累计评价法应成为高中男生1 000米、女生800米学生学习评价内容;数量累计评价法和标准能有效地激发高中生学习体育的兴趣,特别是低水平学生的学习兴趣。 相似文献
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The phylogenetic position of hyoliths has long been unsettled, with recent discoveries of a tentaculate feeding apparatus (‘lophophore’) and fleshy apical extensions from the shell (‘pedicle’) suggesting a lophophorate affinity. Here, we describe the first soft parts associated with the feeding apparatus of an orthothecid hyolith, Triplicatella opimus from the Chengjiang biota of South China. The tuft-like arrangement of the tentacles of T. opimus differs from that of hyolithids, suggesting they collected food directly from the substrate. A reassessment of the feeding organ in hyolithids indicates that it does not represent a lophophore and our analysis of the apical structures associated with some orthothecids show that these represent crushed portions of the shell and are not comparable to the brachiopod pedicle. The new information suggests that hyoliths are more likely to be basal members of the lophotrochozoans rather than lophophorates closely linked with the Phylum Brachiopoda. 相似文献
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运用文献资料、专家访谈和粗糙集权重确定等方法,对1999-2005年甘肃省体工队中长跑队员训练和比赛中的最好成绩进行粗糙集权重分析,结果表明:影响10000 m成绩的关键指标是公路10 km和周弓箭步总量;并且从属性决策中得出了5条确定性预测规则.目的在于教练员依据运动员的成绩发展水平提供一个科学训练的方法和手段,为教练员最优控制训练过程提供有效参考. 相似文献
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《国家学生体质健康标准》中心血管机能评价指标同质性的研究 总被引：2，自引：0，他引：2
为了分析《国家学生体质健康标准》中心血管功能评价指标的同质性和有效性,对16586名大学生进行体质健康测试,其中12202名大学生既参加台阶试验又参加800／1000m跑,而且为了得到最大摄氧量的数据,又选取参加台阶试验和800／1000m跑的学生195人进行12分钟跑测试。研究结果表明,大学生的台阶测试得分和耐久跑成绩得分有极其显著差异（P〈0．001）;男女大学生的台阶测试得分与耐久跑得分之间有显著相关性（男生r=0．347,Sig．=0．000;女生r=0．240,Sig．=0．000）,但都呈现低度相关;台阶测试和耐久跑指标之间同质性低;男大学生最大耗氧量与台阶试验测试值、台阶试验得分有显著线性相关关系（h=0．417,P〈0．001）;男大学生最大耗氧量与1000m跑运动成绩及得分之间也有显著线性相关关系（r2=0．616,P〈0．001）。女大学生最大耗氧量与台阶试验测试值、台阶试验得分无显著线性相关关系（r3=0．163,P〉0．05）。最大耗氧量与800m跑运动成绩及得分之间却存在显著线性相关关系（r4=0．464,P〈0．001）。 相似文献
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高璐 《涪陵师范学院学报》2006,22(4):146-149
SA8000标准认证在给中国企业获得更多市场份额和经济上的正反馈效应,树立企业负责任的正面形象、增加消费者对企业和产品的信任度等优势的同时,也会对出口和国际竞争力等方面产生不利影响。因此,要扬长避短,实行不全面推行SA8000认证,完善相关劳动法律的执行等对策来加以应对,以期在经济全球化和贸易自由化的进程中能更好地解决我国的劳工问题。 相似文献
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Guo-qing Ding Yan-lan Yu Zhou-jun Shen Xie-lai Zhou Shan-wen Chen Guo-dong Liao Yue Zhang 《Journal of Zhejiang University. Science. B》2012,13(5):335-341
Objective:Our objective was to construct a recombinant bacillus Calmette-Guérin vaccine(rBCG) that secretes human interferon-alpha 2b(IFNα-2b) and to study its immunogenicity and in vitro antitumor activity against human bladder cancer cell lines T24 and T5637.Methods:The signal sequence BCG Ag85B and the gene IFNα-2b were amplified from the genome of BCG and human peripheral blood,respectively,by polymerase chain reaction(PCR).The two genes were cloned in Escherichia coli-BCG shuttle-vector pMV261 to obtain a new recombinant plasmid pMV261-Ag85B-IFNα-2b.BCG was transformed with the recombinant plasmid by electroporation and designated rBCG-IFNα-2b.Mononuclear cells were isolated from human peripheral blood(PBMCs) and stimulated with rBCG-IFNα-2b or wild type BCG for 3 d,and then cultured with human bladder cancer cell lines T24 and T5637.Their cytotoxicities were measured by 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide(MTT) assay.Results:BCG was successfully transformed with the recombinant plasmid pMV261-Ag85B-IFNα-2b by electroporation and the recombinant BCG(rBCG-IFNα-2b) was capable of synthesizing and secreting cytokine IFNα-2b.PBMC proliferation was enhanced significantly by rBCG-IFNα-2b,and the cytotoxicity of PBMCs stimulated by rBCG-IFNα-2b to T24 and T5627 was significantly stronger in comparison to wild type BCG.Conclusions:A recombinant BCG,secreting human IFNα-2b(rBCG-IFNα-2b),was constructed successfully and was superior to control wild type BCG in inducing immune responses and enhancing cytotoxicity to human bladder cancer cell lines T24 and T5637.This suggests that rBCG-IFNα-2b could be a promising agent for bladder cancer patients in terms of possible reductions in both clinical dosage and side effects of BCG immunotherapy. 相似文献
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De Vries C 《The Journal of perinatal education》2010,19(3):4-7
Our daily lives are a series of ordinary moments and unnoticed thresholds-times that define us in ways we often do not give much attention. While we consider childbirth to be one of life's extra-ordinary events, the hours of labor and birth need not be dramatic (or traumatic) ones. I describe a quiet, well-supported birth in the Netherlands that is cause for celebration of the beauty of an ordinary instant that can define and enrich the human experience. 相似文献
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When quasiparticles move in condensed matters, the texture of their internal quantum structure as a function of position and momentum can give rise to Berry phases that have profound effects on the material’s properties. Seminal examples include the anomalous Hall and spin Hall effects from the momentum-space Berry phases in homogeneous crystals. Here, we explore a conjugate form of the electron Berry phase arising from the moiré pattern: the texture of atomic configurations in real space. In homobilayer transition metal dichalcogenides, we show that the real-space Berry phase from moiré patterns manifests as a periodic magnetic field with magnitudes of up to hundreds of Tesla. This quantity distinguishes moiré patterns from different origins, which can have an identical potential landscape, but opposite quantized magnetic flux per supercell. For low-energy carriers, the homobilayer moirés realize topological flux lattices for the quantum-spin Hall effect. An interlayer bias can continuously tune the spatial profile of the moiré magnetic field, whereas the flux per supercell is a topological quantity that can only have a quantized jump observable at a moderate bias. We also reveal the important role of the non-Abelian Berry phase in shaping the energy landscape in small moiré patterns. Our work points to new possibilities to access ultra-high magnetic fields that can be tailored to the nanoscale by electrical and mechanical controls. 相似文献
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