To determine the cause of the severe drought that hit five provinces (autonomous regions, municipalities) of Southwest China in 2010, the ecological water demand (EWD) of regional vegetation was explored. The key scientific question was whether the plantation of Eucalyptus and Hevea trees in this area could have led to the breaking of the regional EWD balance, thereby causing a regional drought. Therefore, major research progress and trends related to EWD of vegetation, such as characterization of vegetation water consumption from transpiration and eco-hydrological effects, were explored. Theories, methods, and practices regarding EWD of vegetation, and the correlation between regional vegetation types and droughts were evaluated. Finally, suggestions were made for specific scientific research on temporal and spatial evolution of typical artificial vegetation in Southwest China and on the relationship between EWD from regional vegetation and droughts. Thus, future research should include the following three aspects: (i) historical evolution and distribution pattern of regional artificial vegetation; (ii) water consumption from transpiration, water saving for drought prevention, and water and soil conservation of regional artificial vegetation; and (iii) the relationship between EWD of regional artificial vegetation and regional droughts. The proposed research focus is expected to provide a scientific basis for identifying the causes of regional droughts and the reasonable allocation of water resources. In addition, it will be of great importance in guiding restoration and reconstruction of regional artificial vegetation.
Aporphine alkaloids from the leaves of Nelumbo nucifera Gaertn are substances of great interest because of their important pharmacological activities, particularly anti-diabetic, anti-obesity, anti-hyperlipidemic, anti-oxidant, and anti-HIV's activities. In order to produce large amounts of pure alkaloid for research purposes, a novel method using high-speed counter-current chromatography (HSCCC) was developed. Without any initial cleanup steps, four main aporphine alkaloids, including 2-hydroxy-1-methoxyaporphine, pronuciferine, nuciferine and roemerine were successfully purified from the crude extract by HSCCC in one step. The separation was performed with a simple two-phase solvent system composed of n-hexane-ethyl acetate-methanol-acetonitrile-water (5:3:3:2.5:5, v/v/v/v/v). In each operation, 100 mg crude extracts was separated and yielded 6.3 mg of 2-hydroxy-1-methoxyaporphine (95.1% purity), 1.1 mg of pronuciferine (96.8% purity), 8.5 mg of nuciferine (98.9% purity), and 2.7 mg of roemerine (97.4%) respectively. The chemical structure of four aporphine alkaloids are identified by means of electrospray ionization MS (ESI-MS) and nuclear magnetic resonance (NMR) analysis. Moreover, the effects of four separated aporphine alkaloids on insulin-stimulated glucose consumption were examined in 3T3-L1 adipocytes. The results showed that 2-hydroxy-1-methoxyaporphine and pronuciferine increased the glucose consumption significantly as rosiglitazone did.
Soils are the largest sink of atmospheric hydrogen contributing about 75% to the total budget. Atmospheric H, is assumed to be oxidized in soil by abiontic soil hydrogenases. Extraction of a forest soil with a slightly alkaline (pH 8.5) buffer containing polyethylene glycol (PEG), followed by filtration yielded a bacteria-free extract that oxidized H-2 at ambient concentrations (0.2-2.0 ppmv). Hydrogenase activity was assayed by gas chromatographic analysis of H-2 consumption and by conversion of H-3(2) to tritiated water. Only less than 2% of the original activity was recovered in the extract. Kinetic analysis nevertheless resulted in a biphasic kinetics exhibiting two K-m and V-max values that were similar to those detected in the original soil. In addition, activities of both original soil and soil extract showed similar optima at pH 4-6 and at 30 degrees C, indicating that representative fractions of soil hydrogenases were recovered in the extract. Precipitation with PEG or ultrafiltration allowed further purification of the activity, albeit only about 20% of that in the crude extract could be recovered in the precipitate or the fraction > 100 kDa.
A compact apparatus based on universal detector with electron bombardment ionization has been constructed for surface photocatalytic dynamics. Extremely high vacuum (<5×10-12 Torr) for the detector’s ionization region is achieved using multiple ultrahigh vacuum pumps. In addition to a home-made liquid nitrogen shielding and a turbomolecular pump, a simple and low-consumption titanium sublimation pump, rather than the complicated and high-consumption He cold head1 is used to pump the detector’s ionization region with the high pumping speed for H2. Therefore, the background H2 in the detector can be considerablely reduced. This apparatus will be employed to quantitatively measure the products, like H2 and H, from the surface reaction. A home-made quantitative molecular beam doser is also built2-4, and will be used to acquire temperature program desorption spectra. The apparatus includes the standard surface science tools for preparation and characterization of surface samples, LEED, AES, ion gun and so on. This apparatus will be coupled to a set of femtosecond laser system to study the surface photocatalytic system, like water and methanol on TiO2(110) surfaces.
Superfine mineral materials are mainly resulted from the pulverization of natural mineral resources, and are a type of new materials that can replace traditional materials and enjoy the most extensive application and the highest degree of consumption in the present day market. As a result, superfine mineral materials have a very broad and promising prospect in terms of market potential. Superfine pulverization technology is the only way for the in-depth processing of most of the traditional materials, and is also one of the major means for which mineral materials can realize their application. China is rich in natural resources such as heavy calcite, kaolin, wollastonite, etc., which enjoy a very wide market of application in paper making, rubber, plastics, painting, coating, medicine, environment-friendly recycle paper and fine chemical industries, for example. However, because the processing of these resources is generally at the low level, economic benefit and scale for the processing of these resources have not been realized to their full potential even up to now. Big difference in product indices and superfine processing equipment and technologies between China and advanced western countries still exists. Based on resource assessment and market potential analysis, an in-depth study was carried out in this paper about the superfine pulverization technology and superfine pulverized mineral materials from the point of mineralogical features, determination of processing technologies, analytical methods and applications, by utilizing a variety of modern analytical methods in mineralogy, superfine pulverization technology, macromolecular chemistry, material science and physical chemistry together with computer technology and so on. The focus was placed on the innovative study about the in-depth processing technology and the processing apparatus for kaolin and heavy calcite as well as the application of superfine products. The main contents and the major achievements of this study are listed as follows: 1. Superfine pulverization processing of mineral materials shall be integrated with the study of their crystal structures and chemical composition. And special attention shall be put on the post-processing technologies, rather than on the indices for particle size, of these materials, based on their fields of application. Both technical feasibility and economic feasibility shall be taken into account for the study about superfine pulverization technologies, since these two kinds of feasibilities serve as the premise for the industrialized application of superfine pulverized mineral materials. Based on this principle, preposed chemical treatment method, technology of synchronized superfine pulverization and gradation, processing technology and apparatus of integrated modification and depolymerization were utilized in this study, and narrow distribution in terms of particle size, good dispersibility, good application effects, low consumption as well as high effectiveness of superfine products were achieved in this study. Heavy calcite and kaolin are two kinds of superfine mineral materials that enjoy the highest consumption in the industry. Heavy calcite is mainly applied in paper making, coating and plastics industries, the hard kaolin in northern China is mainly used in macromolecular materials and chemical industries, while the soft kaolin in southern China is mainly used for paper making. On the other hand, superfine pulverized heavy calcite and kaolin can both be used as the functional additives to cement, a kind of material that enjoys the biggest consumption in the world. A variety of analytical methods and instruments such as transmission and scanning electron microscopy, X-ray diffraction analysis, infrared analysis, laser particle size analysis and so on were applied for the elucidation of the properties and the mechanisms for the functions of superfine mineral materials as used in plastics and high-performance cement. Detection of superfine mineral materials is closely related to the post-processing and application of these materials. Traditional detection and analytical methods for superfine mineral materials include optical microscopy, infrared spectral analysis and a series of microbeam techniques such as transmission and scanning electron microscopy, X-ray diffraction analysis, and so on. In addition to these traditional methods, super-weak luminescent photon detection technology of high precision, high sensitivity and high signal to noise ratio was also utilized by the author for the first time in the study of superfine mineral materials, in an attempt to explore a completely new method and means for the study of the characterization of superfine materials. The experimental results are really exciting! The innovation of this study is represented in the following aspects: 1. In this study, preposed chemical treatment method, technology of synchronized superfine pulverization and gradation, processing technology and apparatus of integrated modification and depolymerization were utilized in an innovative way, and narrow distribution in terms of particle size, good dispersibility, good application effects, low consumption as well as high effectiveness of superfine products were achieved in the industrialized production process*. Moreover, a new modification technology and related directions for producing the chemicals were invented, and the modification technology was even awarded a patent. 2. The detection technology of super-weak luminescent photon of high precision, high sensitivity and high signal to noise ratio was utilized for the first time in this study to explore the superfine mineral materials, and the experimental results can be compared with those acquired with scanning electron microscopy and has demonstrated its unique advantages. It can be expected that further study may possibly help to result in a completely new method and means for the characterization of superfine materials. 3. During the heating of kaolinite and its decomposition into pianlinite, the diffraction peaks disappear gradually. First comes the disappearance of the reflection of the basal plane (001), and then comes the slow disappearance of the (hkl) diffraction peaks. And this was first discovered during the experiments by the author, and it has never before reported by other scholars. 4. The first discovery of the functions that superfine mineral materials can be used as dispersants in plastics, and the first discovery of the comprehensive functions that superfine mineral materials can also be used as activators, water-reducing agents and aggregates in high-performance cement were made in this study, together with a detailed discussion. This study was jointly supported by two key grants from Guangdong Province for Scientific and Technological Research in the 10th Five-year Plan Period (1,200,000 yuan for Preparation technology, apparatus and post-processing research by using sub-micron superfine pulverization machinery method, and 300,000 yuan for Method and instruments for biological photon technology in the characterization of nanometer materials), and two grants from Guangdong Province for 100 projects for scientific and technological innovation (700,000 yuan for Pilot experimentation of superfine and modified heavy calcite used in paper-making, rubber and plastics industry, and 400,000 yuan for Study of superfine, modified wollastonite of large length-to-diameter ratio).