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931.
The future development of new-type urbanization has drawn great attention from both the government and public alike. In this context, the present study had three related research aims. Firstly, it sought to predict the urbanization and population dynamics in China at both national and provincial levels for the period of 2015 to 2030. Secondly, on this basis, it sought to examine the spatial variation of urbanization given the predicted national urbanization rate of 70.12%. Thirdly, it sought to estimate and evaluate the national and provincial demands of investment in the development of new-type urbanization. The main conclusions from this study were as follows: (1) The population size and urbanization rate will reach 1.445 billion and 70.12%, respectively, from 2015 to 2030. (2) The demographic dividend will vanish when the population pressure reaches its maximum. During this period, there will be 70.16 million urban population born. The suburban population that becomes urbanized will be 316.7 million, and thus the net increase in urban population will reach 386 million. (3) Although the urbanization rate of every Chinese province will increase during 2015–2030, it will do so unequally, while differences in urbanization quality among provinces will also be substantial. In some provinces, moreover, the urbanization quality is not compatible with their eco-social development. (4) A total of 4,105,380 billion yuan is required to fund new-type urbanization and the investment demand for each province varies greatly; for example, Guangdong province requires the most funding, amounting to approximately 148 times that required by Tibet, the province in least need of funding. In the final part of this study, policy suggestions concerning the investment of the new-type urbanization are put forward and discussed.  相似文献   
932.
Patterns of septal insertion were analyzed in three species of Agetolites from the Upper Ordovician in Yushan County,Jiangxi Province of China.Agetolites is a peculiar coral possessing features of both tabulate(e.g.,mural pores)and rugose corals(e.g.,well-developed septa).Septal patterns have long been considered to be indicative of the origin of corals,and the pattern of septal insertion in Agetolites has been known to be typical of rugosans.This study,however,reveals that the patterns in Agetolites are rather random and cannot be an indication of its rugosan affinity.It is suggested that Agetolites probably has a closer phylogenetic relation with tabulates than with either rugosans or scleractinians.Two insertion patterns of the first six septa were detected(Types Ⅰ and Ⅱ).Type I is interpreted as scleractinian pattern whereas Type II as typical pattern of rugosans.Types 1 and 2 are septal patterns of the second stage recognized in this study.Type 1 insertion occurs in six sectors located in the center of each interseptal space,suggesting scleractinian pattern of insertion.Type 2 insertion occurs in four sectors that are comparable with alar and counter sectors in rugose corals.Four patterns of the third(Types A–D)and fourth stages(Types a–d)of septal insertion have also been recognized in Agetolites.Type A only occurs in two adjacent sectors possibly due to the incompleteness of septal development.Type B presents rugosan pattern.Types C and D resemble scleractinian pattern in most aspects.Types a,b,and c present no clear attribution to rugosan or scleractinian pattern probably due to the incompleteness of septal development whereas Type d is observable in rugose corals.  相似文献   
933.
The primary productivity of terrestrial ecosystems is influenced by soil phosphorus bioavailability, which depends largely on chemical fractions of phosphorus. The sequential fractionation technique developed by Hedley et al. or its subsequent modification is a well-known method to determine soil phosphorus forms. Hedley sequential fractionation technique separates the phosphorus into fractions based on their different chemical solubilities in extractants with certain chemical properties. Recently, synchrotron-based X-ray absorption near edge structure (XANES) spectroscopy has been employed to measure soil phosphorus species directly and non-invasively. The XANES method provides information concerning local structure and chemical information of target elements at a molecular level. Thus, it can distinguish phosphorus fractions bound by metal oxides or hydroxides (such as Fe, Al, and Ca). In this present work, the phosphorus speciation of topsoil along a glacial foreland chronosequence in Gongga Mountain is determined using these two methods. The changes in soil phosphorus bioavailability along the 120-year-old chronosequence are assessed based on comparisons of the results obtained by these two methods. The results indicate that Hedley sequential fractionation technique shows a greater ability to determine soil bioavailable phosphorus (Resin-P and NaCHO3-P), while XANES is effective in distinguishing phosphorus bound by metal compounds. In the chronosequence, Ca- and Al-bound phosphorus were derived mainly from primary minerals, whose phosphorus contents decreased within 120 years of moraine weathering and soil development. The content of soil bioavailable phosphorus increased rapidly after 30 years since deglaciation. The increasing phosphorus bioavailability promoted the colonizing and primary succession vegetation.  相似文献   
934.
为了研究混凝土在冻融交替与盐类侵蚀双重因素作用下的抗冻耐久性能,根据季节冻土区大安境内盐渍土中主要易溶盐的类型与含量,配制了3种质量分数的复合盐侵蚀溶液,制备了普通混凝土、2种引气混凝土及2组粉煤灰混凝土试件,进行盐蚀[CD*2]快速冻融循环试验,对盐冻破坏后混凝土的质量损失、动弹性模量衰减及其微观结构进行分析。试验结果表明:在冻融循环作用下,复合盐加剧了混凝土的冻融剥蚀破坏;混凝土的冻害程度与侵蚀盐溶液的质量分数、冻融循环次数、混凝土的含气量、粉煤灰掺量等因素有关;造成混凝土发生盐冻破坏的原因有水结成冰的膨胀压力,或冰与水的渗透压力以及复合盐与水泥水化产物发生的化学侵蚀和盐类的结晶膨胀,其中,盐类结晶压对混凝土内部结构的破坏更严重。  相似文献   
935.
近年来强沙尘暴天气气候特征的分析研究   总被引:21,自引:3,他引:18  
2000~2002年春季(3~5月)中国北方有12次强沙尘暴天气过程发生,其中11次与蒙古气旋有关.作者从干旱气候背景、环流状况、沙尘源、沙尘路径及天气系统等方面进行了分析,并集中对引发强沙尘暴的蒙古气旋进行了诊断分析.结果表明:在这3年中,春季我国北方强沙尘暴天气主要与蒙古气旋的发展移动有关,气旋冷锋后的大风是强沙尘暴天气发生的主要动力因子;蒙古国南部、巴丹吉林沙漠、腾格里沙漠、乌兰布和沙漠和毛乌素沙地是强沙尘暴过程的主要沙尘源地;影响我国的强沙尘暴的沙尘路径至少可分为3种类型,即偏西路径、西北路径和南疆盆地型,以西北路径居多;我国北方春季的连续干旱、气温偏高及冷空气活跃是强沙尘暴天气形成的重要气候背景.  相似文献   
936.
We propose a bio-optical inversion model that retrieves the absorption contributions of phytoplankton and colored detrital matter(CDM),as well as the phytoplankton size classes(PSCs),from total minus water absorption spectra.The model is based on three-component separation of phytoplankton size structure and a genetic algorithm.The model performance was tested on two independent datasets(the NASA bio-Optical Marine Algorithm Dataset(NOMAD) and the northern South China Sea(NSCS) dataset).The relationships between the estimated and measured values were strongly linear,especially for aCDM(412),and the Root Mean Square Error(RMSE) of the CDM exponential slope(SCDM) was relatively low.Next,the inversion model was directly applied to in-situ total minus water absorption spectra determined by an underwater meter during a cruise in September 2008,to retrieve the phytoplankton size structure in the seawater.By comparing the measured and retrieved chlorophyll a concentrations,we demonstrated that total and size-specific chlorophyll a concentrations could be retrieved by the model with relatively high accuracy.Finally,we applied the bio-optical inversion model to investigate changes in phytoplankton size structure induced by an anti-cyclonic eddy in the NSCS.  相似文献   
937.
分析降雨、大风、雷电、观测室进人、放炮、断电及仪器故障等各种干扰事件对荥阳地震台数字化形变固体潮分钟值的影响。  相似文献   
938.
The present study investigated the removal of inorganic arsenic from Pinctada martensii enzymatic hydrolysate through unmodified resin (D296) and Zr(IV)-loaded chelating resin (Zr-D401). By loading Zr to macroporous chelating resin D401, the as exchange adsorption active sites are generated. This transforms D401 from a material that does not have the arsenic adsorption capacity into a material that has excellent arsenic exchange adsorption capacity. The static adsorption experiments were conducted to investigate the optimal removal condition for D296 and Zr-D401. The experimental results show that: the optimum condition for D296 is that T= 25°C, pH = 5, resin additive amount = 1 g (50 mL)?1, and contact time = 10 h, the corresponding arsenic removal rate being 65.7%, and protein loss being 2.33%; the optimum condition for Zr-D401 is that T=25°C, pH = 8, resin additive amount = 1 g (50 mL)?1, and contact time=10 h, the corresponding arsenic removal rate being 70.3%, and protein loss being 4.65%. These results show that both of the two resins are effective in arsenic removal for preserving useful substance. Our research provides scientific evidence and advances in the processing technology for heavy metal removal in shellfish.  相似文献   
939.
This paper describes a set of on-site earthquake safety evaluation systems for buildings, which were developed based on a network platform. The system embedded into the quantitative research results which were completed in accordance with the provisions from Post-earthquake Field Works, Part 2: Safety Assessment of Buildings, GB18208.2-2001, and was further developed into an easy-to-use software platform. The system is aimed at allowing engineering professionals, civil engineeing technicists or earthquake-affected victims on site to assess damaged buildings through a network after earthquakes. The authors studied the function structure, process design of the safety evaluation module, and hierarchical analysis algorithm module of the system in depth, and developed the general architecture design, development technology and database design of the system. Technologies such as hierarchical architecture design and Java EE were used in the system development, and My SQL5 was adopted in the database development. The result is a complete evaluation process of information collection, safety evaluation, and output of damage and safety degrees, as well as query and statistical analysis of identified buildings. The system can play a positive role in sharing expert post-earthquake experience and promoting safety evaluation of buildings on a seismic field.  相似文献   
940.
Native gold, platinum, nickel, and other ore minerals have been discovered in graphite-bearing rocks of the Liumao deposit (Heilongjiang province, China). The results obtained are similar to the previously published materials on the mineralogy of carbon-rich formations of the Tamga and Turgenevo deposits (Primorye, Russian Far East) located in the same region of graphitization in the Khankai terrane as the Chinese object. The defined similarities are most likely explained by participation of deep reduced fluids in the process of ore genesis.  相似文献   
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