俯冲带榴辉岩中水的赋存机制及其溶解度的控制因素

榴辉岩是俯冲带重要的高压—超高压变质岩石类型之一,其主要组成矿物为石榴子石和绿辉石,是名义上无水矿物(NAMs)。随着板片俯冲过程中温度压力的升高,富水流体被释放,但榴辉岩中的石榴子石和绿辉石仍然可以携带一定量的水,成为水向地球内部传输的重要载体。在超高压岩石折返过程中,由于压力的降低,石榴子石和绿辉石中的水以羟基出溶的方式释放,能够引起高压变质岩石的退变质甚至同折返岩浆等一系列重要地球动力学过程。文章论述了矿物含水性的研究方法、石榴子石和绿辉石中水的赋存机制、水溶解度的控制因素(例如化学组成、压力、温度、水逸度、氧逸度等)以及板片俯冲/折返过程中榴辉岩水的行为,在此基础上凝炼当前研究中面临的科学问题展望了未来的研究方向。

Effects of therapies for regulating and reinforcing lung and kidney on osteoporosis in rats with chronic obstructive pulmonary disease

OBJECTIVE:To evaluate the efficacy and long-term effects of the three therapies for regulating and reinforcing lung and kidney(reinforcing lung and invigorating spleen,reinforcing lung and replenishing kidney,and supplementing Qi and nourishing kidney) in Traditional Chinese Medicine(TCM) on osteoporosis in rats with chronic obstructive pulmonary disease.METHODS:Totally 120 rats were randomly divided into control,model,Bufeijianpi,Bufeiyishen,Yiqizishen,aminophyline groups.Repeated smoke inhalations and bacterial infections were used to duplicate the stable Chronic obstructive pulmonary disease rat model.Normal saline was given to the air control and model groups,while Bufeijianpi granule,Bufeiyishen granule,and Yiqizishen granule,and aminophylline were administrated to rats in the Bufeijianpi,Bufeiyishen,Yiqizishen,and aminophylline groups respectively from weeks 9 through 20.Another 12 weeks without medicines to observe the long-term effect.Rats were sacrificed at week 20 and week 32.Bone mass density(BMD),bone mineral content(BMC),morphology of the femoral head,lung function,and levels of serum interleukin(IL)-1β,IL-6,and tumor necrosis factor-a were detected.RESULTS:At weeks 20 and 32,tidal volume,peak expiratory flow and expiratory flow at 50% tidal volume in the three TCM-treated groups were higher than those in the model group(P < 0.05).Femur weight,BMD,and BMC were significantly higher in the three TCM-treated groups and the aminophylline-treated group compared with the model group(P < 0.01),except for BMC in the Yiqizishen-treated group at week 20.CONCLUSION:Bufeijianpi,Bufeiyishen,and Yiqizishen granules show good effects in the prevention and treatment of osteoporosis,which can alleviate airflow limitations and inflammation,improve BMD and BMC of the femur,and have favorable long-term effects.

CO_2 Sequestration from flue gas by direct aqueous mineral carbonation of wollastonite

Emission of carbon dioxide is considered to be the main cause of the greenhouse effect. Mineral carbonation, an important part of the CCS technology, is an attractive option for long-term CO2 sequestration. In this study, wollastonite was chosen as the feedstock and the feasibility of direct aqueous mineral carbonation in the simulated flue gas was investigated via a series of experimental studies carried in a stirred reactor. X-ray diffraction （XRD）, X-ray fluorescence spectroscopy （XRF）, ion chro- matography （IC） and thermal decomposition were used to determine the carbonation conversion. The influences of various factors, including reaction temperature, reaction pressure, solution composition, heat-treatment and particle size, were dis- cussed. Concurrently, the effects of SO2 and NO presented in simulated flue gas were also investigated and a possible mecha- nism was used to explain the results. Experimental results show that reaction temperature, reaction pressure and particle size can effectively improve the carbonation reaction. Addition of 0.6 M NaHCO3 was also proved to be beneficial to the reaction and heat-treatment is not needed for wollastonite to get a higher carbonation conversion. Compared with carbonation in puri- fied CO2 gas, CO2 sequestration directly from simulated flue gas by mineral carbonation is suggested to have a certain degree of economic feasibility in the conditions of medium and low-pressure. A highest carbonation conversion of 35.9% is gained on the condition of T=150℃, P=40 bar and PS 〈30 μ in distilled water for 1 h.

Water-enhanced plastic deformation in felsic rocks

Using Fourier transform infrared spectroscopy(FTIR),we measured water contents in quartz and feldspar for four kinds of felsic rocks,i.e.,undeformed granite,banded granitic gneiss,fine-grained felsic mylonite,and fine-grained quartz-mica schist,collected from Pengguan Complex and Kangding Complex in the Longmenshan tectonic zone,Sichuan,China.The absorbance spectra suggest that water in coarse-grained quartz and feldspar of undeformed granite and banded granitic gneiss occurs mainly as hydroxyl in crystal defects,and water in most of fine-grained quartz and feldspar of felsic mylonite is molecular water in inclusions and liquid-type water in grain boundaries,but in some cases it still occurs as hydroxyl in crystal defects.Water content of quartz in undeformed granite is 0.001 wt%-0.009 wt %,and that of feldspar 0.005 wt%-0.02 wt%.The banded granitic gneiss shows water contents of 0.002 wt%-0.011 wt% in quartz and 0.012 wt%-0.036 wt% in feldspar.Quartz ribbon and feldspar ribbon in fine-grained felsic mylonite show that their water contents are similar to those of coarse-grained quartz and feldspar in granite,0.002 wt%-0.011 wt%,and 0.004 wt%-0.02 wt%,respectively.Water contents of fine-grained quartz and feldspar are respectively 0.004 wt%-0.02 wt% and 0.012 wt%-0.06 wt%.Water content of quartz in fine-grained quartz-mica schist is 0.007 wt%-0.15 wt%.Water-bearing minerals display much higher water contents than those of nominally anhydrous minerals,and the percentage of water-bearing minerals in felsic rocks increases with the strain of rocks.These new data indicate that hydroxyl in crystal defects has basically not been released during the shear deformation,and on the contrary,the increase in molecular water in inclusions and liquid-type water in grain boundaries as well as water-bearing minerals after shear deformation leads to a significant increase of the water content in deformed rocks.Based on data of creep tests,it is inferred here that the fine-grained mylonites with more water have much lower strength than that of the weakly deformed coarse-grained rocks in the middle crust,and this indicates that trace amount of water significantly helped develop the ductile shear zone.

Methodological progress in trace amounts of structural water in nominally anhydrous minerals

In the deep Earth, hydrogen mainly occurs as structural hydroxyl and molecular water in minerals and melts, constituting mobile and immobile aqueous components. Hydrous minerals contain hydrogen which occupies a specific structural position and constitutes an indispensable component of chemical formulae. On the other hand, nominally anhydrous minerals do not contain hydrogen in their chemical formulae, but can host trace amounts of water in structural position and lattice defect. The molecular water may occur in the lattice defect as fluid/melt inclusions in minerals. Even though the water content of nominally anhydrous minerals is very limited generally in the order of ppm(parts per million), they may play a significant role in influencing the physicochemical properties of mineral and rock systems. With the continuous improvement of modern instrumentations, the analytical methodology exhibits trends for higher spatial resolution, lower detection limit and integral multiple methods on the water amount and its isotopic ratio. Among these methods, Fourier transform infrared spectrometry remains the most widely used, while secondary ion mass spectrometry, continuous flow mass spectrometry, elastic recoil detection analysis and Raman spectrometry are promising. This paper provides a brief review on the methodological progress and their applications to the analysis of structural water in nominally anhydrous minerals.