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排序方式: 共有173条查询结果,搜索用时 15 毫秒
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田园城市理论对小城镇规划发展的启示 总被引:1,自引:0,他引:1
分析霍华德田园城市理论的主要内容,并从城乡结合、生态环境、公共与基础设施服务、小城镇发展的规模与数量、建设资金来源等方面探究小城镇的规划发展. 相似文献
63.
招投标文本具有一般法律文本的基本语言特征,如措词精当、结构严谨、术语专业、思维缜密、文体正规、语意明确,这对招投标文件的翻译提出了很高的要求。当前译界还没有对标书文本的翻译进行探讨,文章试图对此作一个有益的尝试,以期为类似文本的翻译提供借鉴。 相似文献
64.
凝血因子Ⅸ基因剔除小鼠遗传稳定性及其临床表型研究 总被引:7,自引:0,他引:7
通过对凝血因子Ⅸ基因剔除小鼠遗传稳定性及其相应临床表型的研究,为以该动物模型为研究对象的血友病B基因治疗提供相应背景资料,遗传分析表明,该小鼠繁殖过程中无回复突变出现,亦未发现Ⅸ因子基因未敲除部分被转录的证据;血浆PT,KPTT和Ⅸ因子活性检定结果提示该小鼠符合人血友病B相应临床表征。 相似文献
65.
Preliminary results of the study on wind erosion in the Qinghai-Tibetan Plateau using137Cs technique
The worldwide fallout of caesium-137 (137Cs) associated with the nuclear weapon tests during the 1950s and 1960s has provided a valuable man-made tracer for studies
of soil erosion and sediment delivery. But relatively few researchers have used it to estimate wind erosion. In this note,
the137Cs technique is introduced into the studies of wind erosion and its modern processes in the Qinghai-Tibetan Plateau. Two137Cs reference inventories of 982.11 and 2 376.04 Bq · m−2 were established preminarily, distributed in the south and middle-north parts of the studied area respectively. By analyzing
the patterns of137Cs depth profiles from sampling sites, the aeolian processes of erosion and deposition in nearly 40 years have been revealed,
i.e. the shrub coppice dunes (S1) and semi-fixed dunefields (S3) experienced the alternation of erosion and deposition, while
the grasslands (S4, S6 and S7) and dry farmlands (S5) suffered erosion only. By using137Cs model, the average wind erosion rates for shrub coppice dune (S1), semi-fixed dune fields (S3), dry farmlands (S5) and
grasslands (S4, S6 and S7) were estimated to be 84.14, 69.43, 30.68 and 21.84 t · ha1 · a−1 respectively, averaging 47.59 t · ha−1 · a−1 for the whole plateau, which can be regarded as of the medium erosion standard. These results derived from Cs for the first
time have significant implications for the further research of wind erosion and desertification control in the Qinghai-Tibetan
Plateau. 相似文献
66.
VAN DER KLOOT WG 《Nature》1956,178(4529):366-367
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Three electrokinetic(EK) experiments were designed to study the remediation efficiency of Cr(Ⅲ) by EK-oxidation method and to investigate the influence of complexes and p H buffer solution in EK-oxidation process. Sediments Cr(Ⅲ) can be oxidized into Cr(Ⅵ) effectively by KMn O4, but the oxidation efficiency is not proportional to the dose of oxidant, and chemical oxidation process leads to a bit lower buffering capacity of the sediment. Compared with the simple EK remediation, the removal efficiency of total Cr in the sediments increased 32.6% by EK-oxidation method, and the concentrations of total chromium in the sediment showed increasing trend from the cathode to the anode after EK-oxidation treatment. The p H control and KMn O4 improved the removal of Cr(Ⅵ) and total Cr from the sediments. Due to stronger complexation action of citric acid with Cr(Ⅲ) in sediments, citric acid in the catholyte obviously increased the removal rate of total Cr in sediments. Finally, the removal rate of total Cr from sediments reached 60.9% by adding complex and controlling the p H of cathode and anode pond solution on EK-oxidation processes. 相似文献
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