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1.
本文主要综述了湿地的水资源量、水质评价、水环境功能、水环境存在的主要问题及保护等方面的主要进展,并从加强湿地水环境的多学科协同研究,倡导多样化、个性化的研究,采取"问题取向"进行整合性研究等方面提出湿地水环境研究存在的问题及展望.  相似文献   

2.
近年来,随着图书馆火灾的频繁发生,学界也加强了对图书馆火灾的研究,其探讨的主要内容集中在火灾隐患和火灾成因研究、火灾危害性研究、火灾预防研究、火灾发生后的应急举措及防火技术研究等方面.研究的不足在理论、内容及方法等方面各有表现.在以后的研究当中应该同时关注以上几个方面,才能使该领域的研究上升到一个新的高度.  相似文献   

3.
药材川续断的研究进展   总被引:1,自引:0,他引:1  
从基础研究、天然化学成分及药理作用、提取工艺及药材质量评价方面综述了川续断的研究概况.该植物主要含皂苷、生物碱、挥发油等活性成分,在增强机体免疫功能、抗氧化、促进骨愈合等方面显示了较好的作用.提出了目前川续断以及其他药材质量评价方面存在的问题,以及今后的研究趋势.  相似文献   

4.
砂土液化判别的研究现状及存在问题   总被引:3,自引:0,他引:3  
就目前国内外砂土液化机理研究、砂土液化动力分析方法及液化判别方法等方面的研究现状做了简要的归纳和评述。在液化判别方法方面,主要认为目前有Seed简化分析法、经验分析法、概率统计分析法、室内试验分析法及土层反应分析法等方法。最后,对砂土液化判别研究方面的一些不足之处提出了解决的思路。  相似文献   

5.
梁立哲 《科技信息》2010,(16):I0193-I0193
风电机组的气动载荷计算极其复杂,涉及电器、结构及气动等多个方面,而且这几个方面的耦合作用会使问题更加复杂。为了仿真研究机组的气动载荷特性,本文联合应用TurbSim,AeroDyn及FAST软件,综合考虑电器、结构及气动等三个方面及其耦合影响,仿真研究风电机组的载荷动态。  相似文献   

6.
从鲁南文化研究、鲁南文化产业化研究及鲁南文化与旅游产业融合发展研究等方面,梳理研究主题、研究内容及研究进展,为鲁南文化资源产业化研究提供理论指导及借鉴。  相似文献   

7.
通过文献资料认为:目前我国在健美操教学中学生能力的培养方面的研究主要有六个领域,对创新能力、创编能力、表现力及审美能力方面研究较多,而对观察能力、模仿能力等方面的研究较少。  相似文献   

8.
荨麻科艾麻属植物在治疗风湿类疾病方面效果显著,近年来渐受关注。现代的药理研究显示该属植物具有治疗糖尿病、抗菌、抗炎、抗氧化、降血脂及镇痛等作用。本文通过文献查阅整理,对艾麻属植物的资源分布、化学成分及药理作用等方面的研究状况进行综述,以期为该属植物特别是珠芽艾麻进一步研究及合理开发利用提供参考。  相似文献   

9.
以近20年国内外森林结构的内涵及其分类研究结果为研究对象。通过对比分析。探讨森林结构的内涵及分类体系.研究结果表明:森林结构内涵方面,从属性表达、属性维度和对象相互作用等3个方面分析,国外论述较国内论述更加广泛,国内90年代以非空间结构论述为主,2000年以后引入了空间结构;森林结构分类方面,从属性表达、属性维度、对象相互作用、属性状态、地理尺度及生物组织水平等6大方面进行了探索性分类.  相似文献   

10.
运用文献计量法、内容分析法对国内高校图书馆企业信息服务研究领域的学术论文从论文年代分布、期刊分布、高产作者及研究主题等方面进行统计分析,揭示了高校图书馆开展企业信息服务的发展趋势、研究特点及研究热点等。  相似文献   

11.
Language markedness is a common phenomenon in languages, and is reflected from hearing, vision and sense, i.e. the variation in the three aspects such as phonology, morphology and semantics. This paper focuses on the interpretation of markedness in language use following the three perspectives, i.e. pragmatic interpretation, psychological interpretation and cognitive interpretation, with an aim to define the function of markedness.  相似文献   

12.
The Williston Basin is a significant petroleum province, containing oil production zones that include the Middle Cambrian to Lower Ordovician, Upper Ordovician, Middle Devonian, Upper Devonian and Mississippian and within the Jurassic and Cretaceous. The oils of the Williston Basin exhibit a wide range of geochemical characteristics defined as "oil families", although the geochemical signature of the Cambrian Deadwood Formation and Lower Ordovician Winnipeg reservoired oils does not match any "oil family". Despite their close stratigraphic proximity, it is evident that the oils of the Lower Palaeozoic within the Williston Basin are distinct. This suggests the presence of a new "oil family" within the Williston Basin. Diagnostic geochemical signatures occur in the gasoline range chromatograms, within saturate fraction gas chromatograms and biomarker fingerprints. However, some of the established criteria and cross-plots that are currently used to segregate oils into distinct genetic families within the basin do not always meet with success, particularly when applied to the Lower Palaeozoic oils of the Deadwood and Winnipeg Formation.  相似文献   

13.
王慧 《科技信息》2008,(10):240-240
Wuthering Heights, Emily Bronte's only novel, was published in December of 1847 under the pseudonym Ellis Bell. The book did not gain immediate success, but it is now thought one of the finest novels in the English language. Catherine is the key character of this masterpiece, because everybody and everything center on her though she had a short life. We can understand this masterpiece better if we know Catherine well.  相似文献   

14.
何延凌 《科技信息》2008,(4):258-258
Language is a means of verbal communication. People use language to communicate with each other. In the society, no two speakers are exactly alike in the way of speaking. Some differences are due to age, gender, statue and personality. Above all, gender is one of the obvious reasons. The writer of this paper tries to describe the features of women's language from these perspectives: pronunciation, intonation, diction, subjects, grammar and discourse. From the discussion of the features of women's language, more attention should be paid to language use in social context. What's more, the linguistic phenomena in a speaking community can be understood more thoroughly.  相似文献   

15.
The discovery of the prolific Ordovician Red River reservoirs in 1995 in southeastern Saskatchewan was the catalyst for extensive exploration activity which resulted in the discovery of more than 15 new Red River pools. The best yields of Red River production to date have been from dolomite reservoirs. Understanding the processes of dolomitization is, therefore, crucial for the prediction of the connectivity, spatial distribution and heterogeneity of dolomite reservoirs.The Red River reservoirs in the Midale area consist of 3~4 thin dolomitized zones, with a total thickness of about 20 m, which occur at the top of the Yeoman Formation. Two types of replacement dolomite were recognized in the Red River reservoir: dolomitized burrow infills and dolomitized host matrix. The spatial distribution of dolomite suggests that burrowing organisms played an important role in facilitating the fluid flow in the backfilled sediments. This resulted in penecontemporaneous dolomitization of burrow infills by normal seawater. The dolomite in the host matrix is interpreted as having occurred at shallow burial by evaporitic seawater during precipitation of Lake Almar anhydrite that immediately overlies the Yeoman Formation. However, the low δ18O values of dolomited burrow infills (-5.9‰~ -7.8‰, PDB) and matrix dolomites (-6.6‰~ -8.1‰, avg. -7.4‰ PDB) compared to the estimated values for the late Ordovician marine dolomite could be attributed to modification and alteration of dolomite at higher temperatures during deeper burial, which could also be responsible for its 87Sr/86Sr ratios (0.7084~0.7088) that are higher than suggested for the late Ordovician seawaters (0.7078~0.7080). The trace amounts of saddle dolomite cement in the Red River carbonates are probably related to "cannibalization" of earlier replacement dolomite during the chemical compaction.  相似文献   

16.
Location based services is promising due to its novel working style and contents.A software platform is proposed to provide application programs of typical location based services and support new applications developing efficiently. The analysis shows that this scheme is easy implemented, low cost and adapt to all kinds of mobile nework system.  相似文献   

17.
以AC-13级配为基础,将橡胶颗粒代替部分集料掺入混合料中,以低温弯曲试验为评价方法对不同橡胶颗粒掺量下沥青混合料的低温抗裂性进行研究,并引入应变能密度值对混合料的低温抗裂性进行综合评价.试验结果表明:橡胶颗粒沥青混合料试件的破坏微应变均超过2 300,满足冬寒区的技术指标;无论是否掺加橡胶颗粒,随着温度的下降,沥青混合料破坏时的最大弯拉强度增大,弯拉应变降低,劲度模量增大;弯曲应变能密度在胶粒掺量为1%左右时具有较大的弯曲应变能密度值,此时橡胶颗粒沥青混合料具有较好的低温抗裂性.  相似文献   

18.
理论推导与室内实验相结合,建立了低渗透非均质砂岩油藏启动压力梯度确定方法。首先借助油藏流场与电场相似的原理,推导了非均质砂岩油藏启动压力梯度计算公式。其次基于稳定流实验方法,建立了非均质砂岩油藏启动压力梯度测试方法。结果表明:低渗透非均质砂岩油藏的启动压力梯度确定遵循两个等效原则。平面非均质油藏的启动压力梯度等于各级渗透率段的启动压力梯度关于长度的加权平均;纵向非均质油藏的启动压力梯度等于各渗透率层的启动压力梯度关于渗透率与渗流面积乘积的加权平均。研究成果可用于有效指导低渗透非均质砂岩油藏的合理井距确定,促进该类油藏的高效开发。  相似文献   

19.
Quality traits in wheat (Triticum aestirum L.) were studied by quantitative trait locus (QTL) analysis in a recombinant inbred line (RIL) population, a set of 131 lines derived from Chuan 35050 × Shannong 483 cross (ChSh). Grains from RILs were assayed for 21 quality traits related to protein and starch. A total of 35 putative QTLs for 19 traits with a single QTL explaining 7.99-40.52% of phenotypic variations were detected on 10 chromosomes, 1D, 2A, 2D, 3B, 3D, 5A, 6A, 6B, 6D, and 7B. The additive effects of 30 QTLs were positive, contributed by Chuan 35050, the remaining 5 QTLs were negative with the additive effect contributed by Shannong 483. For protein traits, 15 QTLs were obtained and most of them were located on chromosomes 1 D, 3B and 6D, while 20 QTLs for starch traits were detected and most of them were located on chromosomes 3D, 6B and 7B. Only 7 QTLs for protein and starch traits were co-located in three regions on chromosomes 1D, 2A and 2D. These protein and starch trait QTLs showed a distinct distribution pattern in certain regions and chromosomes. Twenty-two QTLs were clustered in 6 regions of 5 chromosomes. Two QTL clusters for protein traits were located on chromosomes 1D and 3B, respectively, three clusters for starch traits on chromosomes 3D, 6B and 7B, and one cluster including protein and starch traits on chromosome 1D.  相似文献   

20.
As an American modern novelist who were famous in the literary world, Hemingway was not a person who always followed the trend but a sharp observer. At the same time, he was a tragedy maestro, he paid great attention on existence, fate and end-result. The dramatis personae's tragedy of his works was an extreme limit by all means tragedy on the meaning of fearless challenge that failed. The beauty of tragedy was not produced on the destruction of life, but now this kind of value was in the impact activity. They performed for the reader about the tragedy on challenging for the limit and the death.  相似文献   

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