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991.
992.
Meng Fanchao Li Mingcai Cao Jingfu Li Ji Xiong Mingming Feng Xiaomei Ren Guoyu 《Theoretical and Applied Climatology》2018,133(1-2):521-530
Theoretical and Applied Climatology - Climate plays an important role in heating energy consumption owing to the direct relationship between space heating and changes in meteorological conditions.... 相似文献
993.
Land use change has a profound impact on biodiversity and ecological processes, and is closely related to changes in landscape patterns. This paper introduces the theory and method of land economic niche into landscape ecology, which provides a new method for spatial characterization of urban and rural spatial landscape patterns. Based on this theory, this paper analyzes the landscape pattern of Ganzhou District by using Landsat images as data source in 1995, 2000, 2005,2010 and 2015. We calculated the land economic niche by applying the niche potential theory. Combined with the theory of landscape ecology, we explored the effects of the land economic niche change on the landscape pattern at a county scale.The results show that economic niche of construction land, watershed and farmland increased during 1995–2015, and grassland declined significantly. The economic niche of farmland, construction land, watershed and grassland show a negative correlation with the number of patches(NP), fragmentation index(FN) and the fractal dimension index(FD), and had a positive correlation with the aggregation index(AI). There was no significant correlation between the forest land economic niche and landscape metrics. The change of land economic niche has a driving effect on the landscape pattern of the county, which can represent the economic development direction of Ganzhou District. The land economic niche is closely related to the landscape type which can directly obtain an economic benefit. 相似文献
994.
The alkaline oceanic island basalts(OIBs) with under-saturated SiO_2 and high contents of CaO and alkaline are usually attributed to mantle sources different from typical tholeiitic OIBs.Based on the results of high pressure and temperature experiment study,the genesis of silica under-saturated alkaline basaltic melts could be explained by the role of CO_2, thus,the genetic relationship of alkaline basalts with CO_2 has become a topic of relevance because it is closely related to the deep carbon cycle.The Magellan Seamount chain in the West Pacific Seamount Province has wide distribution of alkali basalts.For the first time,we collected alkaline basalt samples from the Kocebu Seamount of the Magellan Seamount chain and found that magmatic apatites widely occur in the less evolved volcanic rock samples,and the high contents of phosphorus should be a feature of the alkaline OIB s of the Magellan Seamounts.Compared with typical OIBs,these alkaline volcanic rocks have higher CaO and P_2 O_5, lower SiO_2 content,negative anomaly of high field strength elements(HFSEs),more distinctly negative anomaly of potassium(K) and the ubiquity of titanaugite,indicating a CO_2-rich mantle source.Based on the relatively high K2 O and TiO_2 contents and La/Yb ratio and low MgO content of these alkaline rocks,we suggest that the volcanic rocks of the Magellan Seamounts are originated from carbonated eclogites derived possibly from ancient subducted altered oceanic crust. 相似文献
995.
本文基于2016-01~2018-07的Sentinel-1A数据,采用PS-InSAR和SBAS-InSAR时序处理方法获取南昌市主城区地面形变信息,对比2种监测结果,分析产生不均匀地面形变的原因。结果表明,2种时序技术的监测结果相关性较高,南昌市主城区的形变趋势为西北抬升、东南下沉。形变区空间分布存在梅岭抬升区、南昌西火车站沉降区、赣江东岸沉降区、邓家埠沉降区和南钢沉降区,主要受地质构造、含水层介质、地下水开采和城市建设等因素影响。 相似文献
996.
Macroalgae blooms of Ulva prolifera have occurred every summer in the southern Yellow Sea since 2007, inducing severe ecological problems and huge economic losses. Genesis and secular movement of green algae blooms have been well monitored by using remote sensing and other methods. In this study, green algae were detected and traced by using Geostationary Ocean Color Imager(GOCI), and a novel biomass estimation model was developed from the relationship between biomass measurements and previously published satellite-derived biomass indexes. The results show that the green algae biomass can be determined most accurately with the biomass index of green algae for GOCI(BIGAG), which is calculated from the Rsurf data that had been atmospherically corrected by ENVI/QUAC method. For the first time, dynamic changes in green algae biomass were studied over an hourly scale. Short-term biomass changes were highly influenced by Photosynthetically Available Radiation(PAR) and tidal phases, but less by sea surface temperature variations on a daily timescale. A new parameter of biomass changes(PBC), calculated by the ratio of the biomass growth rate to movement velocity, could provide an effective way to assess and forecast green tide in the southern Yellow Sea and similar areas. 相似文献
997.
Ersi Kang Rensheng Chen Zhihui Zhang Xibin Ji Bowen Jin 《Frontiers of Earth Science》2008,2(4):384-392
The challenge is put forward to scientific hydrology by the advancement of water sciences; that is, how should we carry out
a multidisciplinary, integrated and cooperative research on hydrological processes in the basin, regional and global scales,
in order to better understand the role water plays in the changes of the natural resources and environment of the earth, and
to understand the hydrosphere and its interactions with the atmosphere, lithosphere and biosphere. How the changes and transformation
of the components of the water cycle and water balance occur in an inland river basin has yet to be understood. We also need
to understand what the interactions of water cycle, ecosystems and environment are, and what the responses and feedback of
the changes to global change and to human activities are. The water cycle in an inland river basin characterizes the runoff
generation region of the mountains upstream, the artificial oases region of water resources exploitation and utilization midstream
and the natural desert oases region of runoff dissipating downstream. The mountain hydrological processes are discussed from
water cycle, energy balance, water balance and ecological processes. The interactions of water and vegetation are discussed
in relation to ecohydrology, and the hydrological processes in the ground water-soil-vegetation layer are discussed from the
concept of the critical zone newly put forward abroad. The basic frame is put forward to carry out the field measurement,
experiment and studies of hydrological processes in a typical inland river basin.
__________
Translated from Advances in Earth Science, 2007, 22(9): 940–953 [译自: 地球科学进展] 相似文献
998.
Interaction of freshly precipitated silica gel with aqueous solutions was studied at laboratory batch experiments under ambient
and near neutral pH-conditions. The overall process showed excellent reversibility: gel growth could be considered as an opposite
process to dissolution and a linear rate law could be applied to experimental data. Depending on the used rate law form, the
resulting rate constants were sensitive to errors in parameters/variables such as gel surface area, equilibrium constants,
Si-fluxes, and reaction quotients. The application of an Integrated Exponential Model appeared to be the best approach for
dissolution data evaluation. It yielded the rate constants k
dissol ∼ (4.50 ± 0.68) × 10−12 and k
growth ∼ (2.58 ± 0.39) × 10−9 mol m−2 s−1 for zero ionic strength. In contrast, a Differential Model gave best results for growth data modeling. It yielded the rate
constants k
dissol ∼ (1.14 ± 0.44) × 10−11 and k
growth ∼ (6.08 ± 2.37) × 10−9 mol m−2 s−1 for higher ionic strength (I ∼ 0.04 to 0.11 mol L−1). The found silica gel solubility at zero ionic strength was somewhat lower than the generally accepted value. Based on the
and standard Gibbs free energy of silica gel formation was calculated as and −850,318 ± 20 J mol−1, respectively. Activation energies for silica gel dissolution and growth were determined as and respectively. An universal value for growth of any silica polymorph, is not consistent with the value for silica gel growth, which questions the hypothesis about one unique activated complex
controlling the silica polymorph growth. 相似文献
999.
Morphological characters and multi-element isotopic compositions of carbonates from the loess-paleosol sequences in Northwestern China are examined to explore the origin of the minerals. Samples are collected from various sections ranging from Holocene to 0.9 Ma within the sequences and fractions with grain sizes >45 and <2 μm are separated from the bulk soil and examined by SEM and TEM. The results show that the grains >45 μm exhibit an almost perfect spherical shape while those <2 μm are dominated by nano-rods having diameters of 30-50 nm and lengths of 0.3-2 μm, presumably indicating the detrital origin of the coarse fractions and the authigenic characters of the fine ones. Such implications are corroborated by the multi-elemental isotopic compositions of the carbonate minerals. A comparison of the δ13C and δ18O values between minerals and biologically originated samples indicates that the <2 μm fractions have a similar composition to those of coexisting land snail shells. Additional differences between the two size fractions also manifest in the ratios of 206Pb/204Pb, 207Pb/204Pb, 208Pb/204Pb, and 87Sr/86Sr. These results suggest the utility of fine carbonate particles in the soil profile in reconstructing a potentially higher resolution δ13C and δ18O time series to elucidate the paleoclimatic fluctuation in the Chinese Loess Plateau during Pleistocene. The discovery of the nano-rod calcite in Chinese loess, together with previous findings of the similar mineral form in Asian dust, strongly suggests the possibility that these highly reactive CaCO3 form may alter the aerosol properties during transport. 相似文献
1000.
This study was performed to investigate the operating status, evaluate the problems, and discuss possible improvement methods
of passive treatment systems for acid mine drainage (AMD) in South Korea. Thirty-five passive treatment systems in 29 mines
have been constructed from 1996 to 2002 using successive alkalinity producing systems (SAPS) as the main treatment process.
We investigated 29 systems (two for metal mines), 19 of which revealed various problems. Overflows of drainage from SAPS,
wetland, or oxidation ponds were caused by the flow rate exceeding the capacities of the facilities or by the reduced permeability
of the organic substance layer. Leakages occurred at various parts of the systems. In some cases, clogged and broken pipes
at the mouths of the mine adits made the whole system unusable. Some systems showed very low efficiencies without apparent
leakage or overflow. Even though the systems showed fairly good efficiencies in metal removal ratios (mainly iron) and pH
control; sulfate removal rates were very poor except in three systems, which may indicate very poor sulfate reductions with
sulfate reducing bacteria (SRB) as a means. 相似文献