One hundred and twenty single-root teeth were selected to evaluate the bonding durability of three different adhesive resin cements to intra-radicular dentin and the effect of ethylenediaminetetraacetic acid （EDTA） ...One hundred and twenty single-root teeth were selected to evaluate the bonding durability of three different adhesive resin cements to intra-radicular dentin and the effect of ethylenediaminetetraacetic acid （EDTA） irrigation on bonding durability,展开更多
We consider the characteristics of long-term changes in non-tidal gravity and their implication to the local perturbations in barometric pressure and water storage and to the local vertical crustal movement using the ...We consider the characteristics of long-term changes in non-tidal gravity and their implication to the local perturbations in barometric pressure and water storage and to the local vertical crustal movement using the long-term continuous gravity observations from a superconducting gravimeter (SG) at Wu-han station,together with the co-site measurements from a Global Positioning System (GPS) receiver and an absolute gravimeter FG5. The observation results indicate that there are obvious seasonal variations in the long-term gravity changes measured with the SG. About 70 percent of the whole sea-sonal changes come from the contribution of the local disturbances in air pressure and water storage,while over 95 percent of the annual changes are attributed to the loading effects of these environmental perturbations. Due to the absence of direct measurements of the local water storage,especially those of the underground water,the global assimilating models of land water LaD (Land Dynamics) and GLDAS (Global Land Data Assimilation System) cannot virtually describe the real hydrologic distur-bances around the station. The resulting gravity changes,which are simulated theoretically by means of convolution integration of the loading Green’s functions and water models LaD and GLDAS,show significantly time delay of about 55 days from those measured with the SG. Compared with the meas-urements of the absolute gravity with the FG5,the long-term drift rate of the SG is determined as about 17.13 nms-2/a. From the co-site GPS measurements,it is found that the local crust is slowly subsiding at a rate of 3.71±0.16 mm/a,and the related gravity variation is estimated as 13.88±0.22 nms-2/a. In other words,the ratio of the changes in gravity and altitude related to the local vertical crustal movement is about -37.41 nms-2/cm. It implies that a considerable mass adjustment may be associated with the local vertical crustal movement,and its dynamic mechanism should be investigated further.展开更多
Water-conserving membrane is a new material of improving sandy soil. It is based on the rule that a compound with organic and inorganic components can produce colloid after its integrating with Ca2+ in soil. The water...Water-conserving membrane is a new material of improving sandy soil. It is based on the rule that a compound with organic and inorganic components can produce colloid after its integrating with Ca2+ in soil. The water-conserving membrane will obstruct capillary and increase viscidity of sandy soil, so as to decrease leakage and evaporation in sandy soil. The water-conserving membrane contains polyacrylic acid (PAA) and bentonite. When PAA concentration and pH of solution are different, water-conserving membrane can be made in different depth of soil. This experiment shows that the solution with 0.2% PAA does not harm and poison the crops, on the contrary, promotes crop germination. The solution with 0.2% or 0.4% PAA can accelerate corn growth. Accordingly, different crops need the application of the different PAA concentrations in the cultivation. Therefore, on the basis of different vadose coefficient in sandy soil, the solution with different PAA concentration can improve sandy soil and increase its water-conserving competence very well. The solution can be used to improve sandy soil and control desert enlargement in arid, semi-arid and semi-humid areas.展开更多
基金supported by the Science and Technology Program of Zhejiang Province(Nos.2009C33094 and 2013C33126)the Zhejiang Provincial Natural Science Foundation of China(No.Y2080422)
文摘One hundred and twenty single-root teeth were selected to evaluate the bonding durability of three different adhesive resin cements to intra-radicular dentin and the effect of ethylenediaminetetraacetic acid （EDTA） irrigation on bonding durability,
基金the Key Project of the Knowledge Innovation of Chinese Academy of Sciences (Grant No.KZCX2-YW-133)the National Natural Science Foundation of China (Grant Nos.40574034 and 40730316)
文摘We consider the characteristics of long-term changes in non-tidal gravity and their implication to the local perturbations in barometric pressure and water storage and to the local vertical crustal movement using the long-term continuous gravity observations from a superconducting gravimeter (SG) at Wu-han station,together with the co-site measurements from a Global Positioning System (GPS) receiver and an absolute gravimeter FG5. The observation results indicate that there are obvious seasonal variations in the long-term gravity changes measured with the SG. About 70 percent of the whole sea-sonal changes come from the contribution of the local disturbances in air pressure and water storage,while over 95 percent of the annual changes are attributed to the loading effects of these environmental perturbations. Due to the absence of direct measurements of the local water storage,especially those of the underground water,the global assimilating models of land water LaD (Land Dynamics) and GLDAS (Global Land Data Assimilation System) cannot virtually describe the real hydrologic distur-bances around the station. The resulting gravity changes,which are simulated theoretically by means of convolution integration of the loading Green’s functions and water models LaD and GLDAS,show significantly time delay of about 55 days from those measured with the SG. Compared with the meas-urements of the absolute gravity with the FG5,the long-term drift rate of the SG is determined as about 17.13 nms-2/a. From the co-site GPS measurements,it is found that the local crust is slowly subsiding at a rate of 3.71±0.16 mm/a,and the related gravity variation is estimated as 13.88±0.22 nms-2/a. In other words,the ratio of the changes in gravity and altitude related to the local vertical crustal movement is about -37.41 nms-2/cm. It implies that a considerable mass adjustment may be associated with the local vertical crustal movement,and its dynamic mechanism should be investigated further.
基金Undertheauspicesof the of Ministry of ScienceandTechnologyofChina(No.2001BA508B05)
文摘Water-conserving membrane is a new material of improving sandy soil. It is based on the rule that a compound with organic and inorganic components can produce colloid after its integrating with Ca2+ in soil. The water-conserving membrane will obstruct capillary and increase viscidity of sandy soil, so as to decrease leakage and evaporation in sandy soil. The water-conserving membrane contains polyacrylic acid (PAA) and bentonite. When PAA concentration and pH of solution are different, water-conserving membrane can be made in different depth of soil. This experiment shows that the solution with 0.2% PAA does not harm and poison the crops, on the contrary, promotes crop germination. The solution with 0.2% or 0.4% PAA can accelerate corn growth. Accordingly, different crops need the application of the different PAA concentrations in the cultivation. Therefore, on the basis of different vadose coefficient in sandy soil, the solution with different PAA concentration can improve sandy soil and increase its water-conserving competence very well. The solution can be used to improve sandy soil and control desert enlargement in arid, semi-arid and semi-humid areas.
