The work described here was focused on exploring the potential application of coal to purification of oily waste water.Coal was added to oily waste water as an adsorbent and then removed through a flotation process.Th...The work described here was focused on exploring the potential application of coal to purification of oily waste water.Coal was added to oily waste water as an adsorbent and then removed through a flotation process.This allowed economical and highly efficient separation of oil from the waste water.The absorption time,coal type,coal particle size distribution,pH value and oil concentration were investigated.The results indicate that oil absorption by a coal increases for a period of 1.5 h and then gradually tends toward an equilibrium value.It appears that the absorption capacity of anthracite is more than that of lean coal or lignite,given the same coal particle size distribution.The absorption capacity of a coarse coal fraction is less than that of finer coal,given the same of coal type.The absorption capacity of anthracite decreases slightly as the pH increases from 4 to 9.The adsorption of oil on anthracite follows the Freundlich isothermal adsorption law:given initial oil concentrations of 160.5 or 1023.6 mg/L the absorption capacity was 23.8 or 840.0 mg/g.The absorption mechanism consists of two kinds of absorption,a physical process assisted by a chemical one.展开更多
We describe organogenesis at a histological level in American shad( Alosa sapidissima) larvae from 0 until 45 days after hatching(DAH). Larval development was divided into four stages based on the feeding mode,externa...We describe organogenesis at a histological level in American shad( Alosa sapidissima) larvae from 0 until 45 days after hatching(DAH). Larval development was divided into four stages based on the feeding mode,external morphological features,and structural changes in the organs: stage 1(0–2 DAH),stage 2(3–5 DAH),stage 3(6–26 DAH) and stage 4(27–45 DAH). At early stage 2(3 DAH),American shad larvae developed the initial digestive and absorptive tissues,including the mouth and anal opening,buccopharyngeal cavity,oesophagus,incipient stomach,anterior and posterior intestine,differentiated hepatocytes,and exocrine pancreas. The digestive and absorptive capacity developed further in stages 2 to 3,at which time the pharyngeal teeth,taste buds,gut mucosa folds,differentiated stomach,and gastric glands could be observed. Four defined compartments were discernible in the heart at 4 DAH. From 3 to 13 DAH,the excretory systems started to develop,accompanied by urinary bladder opening,the appearance and development of primordial pronephros,and the proliferation and convolution of renal tubules. Primordial gills were detected at 2 DAH,the pseudobranch was visible at 6 DAH,and the filaments and lamellae proliferated rapidly during stage 3. The primordial swim bladder was first observed at 2 DAH and started to inflate at 9 DAH; from then on,it expanded constantly. The spleen was first observed at 8 DAH and the thymus was evident at 12 DAH. From stage 4 onwards,most organs essentially manifested an increase in size,number,and complexity of tissue structure.展开更多
Objectives： To observe the surface characteristics and mechanical behavior of retrieved microimplants under clinically simulating experimental conditions and to investigate the feasibility of rouse of microimplants. ...Objectives： To observe the surface characteristics and mechanical behavior of retrieved microimplants under clinically simulating experimental conditions and to investigate the feasibility of rouse of microimplants. Materials and methods： The microimplants, inserted at different angles, were retrieved from the patients （RMIP） and the artificial bone （RMIA）. Surface characteristics, including morphologic changes of tips and thread edges, length reduction, and surface compositional variation, were evaluated using a field emission scanning electron microscope, a stereoscopic microscope, and energy-dispersive X-ray spectroscopy, respectively. Mechanical behavior comprising maximum insertion torque （MIT） and insertion time was tested with the artificial bone under clinically simulating conditions. Results： The tips and thread edges were worn out to various degrees in retrieved microimplants and thin deposits were observed on the surface in the RMIP group. Traces of foreign elements, such as iron, sulphur, and calcium, were detected on the surface of RMIP. Both MIT and insertion time of retrieved microimplants were increased compared to their initial use, and were much greater in RMIP. The increases of MIT were seen in all groups inserted at the insertion angle of 45~ compared with 90~, although the differences were not statistically significant. Conclusions： Retrieved microimplants exhibited different degrees of changes on surface characteristics and mechanical behavior, with more changes in RMIP. The reuse of microimplants for immediate relocation in the same patient may be acceptable; however, postponed relocation and allogeneic reuse of microimplants are not recommended in clinical practice.展开更多
基金the Science and Technology Fund of China University of Mining & Technology (No.2006A019)the National Natural Science Foundation of China (No.50974119) for their support of this project
文摘The work described here was focused on exploring the potential application of coal to purification of oily waste water.Coal was added to oily waste water as an adsorbent and then removed through a flotation process.This allowed economical and highly efficient separation of oil from the waste water.The absorption time,coal type,coal particle size distribution,pH value and oil concentration were investigated.The results indicate that oil absorption by a coal increases for a period of 1.5 h and then gradually tends toward an equilibrium value.It appears that the absorption capacity of anthracite is more than that of lean coal or lignite,given the same coal particle size distribution.The absorption capacity of a coarse coal fraction is less than that of finer coal,given the same of coal type.The absorption capacity of anthracite decreases slightly as the pH increases from 4 to 9.The adsorption of oil on anthracite follows the Freundlich isothermal adsorption law:given initial oil concentrations of 160.5 or 1023.6 mg/L the absorption capacity was 23.8 or 840.0 mg/g.The absorption mechanism consists of two kinds of absorption,a physical process assisted by a chemical one.
基金Supported by the National Spark Program of China(No.2012GA690001)
文摘We describe organogenesis at a histological level in American shad( Alosa sapidissima) larvae from 0 until 45 days after hatching(DAH). Larval development was divided into four stages based on the feeding mode,external morphological features,and structural changes in the organs: stage 1(0–2 DAH),stage 2(3–5 DAH),stage 3(6–26 DAH) and stage 4(27–45 DAH). At early stage 2(3 DAH),American shad larvae developed the initial digestive and absorptive tissues,including the mouth and anal opening,buccopharyngeal cavity,oesophagus,incipient stomach,anterior and posterior intestine,differentiated hepatocytes,and exocrine pancreas. The digestive and absorptive capacity developed further in stages 2 to 3,at which time the pharyngeal teeth,taste buds,gut mucosa folds,differentiated stomach,and gastric glands could be observed. Four defined compartments were discernible in the heart at 4 DAH. From 3 to 13 DAH,the excretory systems started to develop,accompanied by urinary bladder opening,the appearance and development of primordial pronephros,and the proliferation and convolution of renal tubules. Primordial gills were detected at 2 DAH,the pseudobranch was visible at 6 DAH,and the filaments and lamellae proliferated rapidly during stage 3. The primordial swim bladder was first observed at 2 DAH and started to inflate at 9 DAH; from then on,it expanded constantly. The spleen was first observed at 8 DAH and the thymus was evident at 12 DAH. From stage 4 onwards,most organs essentially manifested an increase in size,number,and complexity of tissue structure.
文摘Objectives： To observe the surface characteristics and mechanical behavior of retrieved microimplants under clinically simulating experimental conditions and to investigate the feasibility of rouse of microimplants. Materials and methods： The microimplants, inserted at different angles, were retrieved from the patients （RMIP） and the artificial bone （RMIA）. Surface characteristics, including morphologic changes of tips and thread edges, length reduction, and surface compositional variation, were evaluated using a field emission scanning electron microscope, a stereoscopic microscope, and energy-dispersive X-ray spectroscopy, respectively. Mechanical behavior comprising maximum insertion torque （MIT） and insertion time was tested with the artificial bone under clinically simulating conditions. Results： The tips and thread edges were worn out to various degrees in retrieved microimplants and thin deposits were observed on the surface in the RMIP group. Traces of foreign elements, such as iron, sulphur, and calcium, were detected on the surface of RMIP. Both MIT and insertion time of retrieved microimplants were increased compared to their initial use, and were much greater in RMIP. The increases of MIT were seen in all groups inserted at the insertion angle of 45~ compared with 90~, although the differences were not statistically significant. Conclusions： Retrieved microimplants exhibited different degrees of changes on surface characteristics and mechanical behavior, with more changes in RMIP. The reuse of microimplants for immediate relocation in the same patient may be acceptable; however, postponed relocation and allogeneic reuse of microimplants are not recommended in clinical practice.
