Tile expressions of interface flee energy （IFE） of composite droplets with meniscal liquid-air interlhce in metastable state on nlicro/nano textured snrfaces were formulated. Then tile parameters to describe the men...Tile expressions of interface flee energy （IFE） of composite droplets with meniscal liquid-air interlhce in metastable state on nlicro/nano textured snrfaces were formulated. Then tile parameters to describe the meniscus were determined based on the principle of minimtun 1FE. Furthermore, the IFE barriers and the necessary and sufficient conditions of drop wetting transition fl＇om Cassie to Wenzel were analyzed and the corresponding criteria were lk^rmulated. The results show that the liquid-air interface below a composite droplet is fiat when the post pitches are relatively small, but in a shape of curved meniscus when the piteches are comparatively large and the curvature depends on structural parameters. The angle between meniscus and pillar wall is just equal to the supplementary angle of intrinsic contact angle of post material. The calculations also illustrate that Cassie droplets will transform to Wenzel state when post pitch is large enough or when drop volume is sufficiently small. The opposite transition from Wenzel to Cassie state, however, is unable to take place spontaneously because the energy barrier is always positive. Finally, the calculation results of this model are well consistent with tile experimental obserwttions in literatures for the wetting transition of droplets from Cassie to Wenzel state.展开更多
Large-scale expansion of the osteoblasts of a Sprague-Dawley(SD)rat was studied in a rotating wall hollow-fiber membrane bioreactor(RWHMB)by using hollow-fiber membrane as the carrier.For the sake of contrast,cells we...Large-scale expansion of the osteoblasts of a Sprague-Dawley(SD)rat was studied in a rotating wall hollow-fiber membrane bioreactor(RWHMB)by using hollow-fiber membrane as the carrier.For the sake of contrast,cells were also expanded in a T-flask using a hollow-fiber membrane as carrier and in a rotating wall vessel bioreactor(RWVB)using a microcarrier.During the culture period,the cells were sampled every 12 h,and after 5 days,the cells were harvested and evaluated with scanning electron microscopy(SEM),hematoxylin-eosin(HE)staining and alkaline phosphatase(ALP)staining.Moreover,von-Kossa staining and Alizarin Red S stain-ing were carried out for mineralized nodules formation.The results show that in RWHMB,the cells present better morphology and vitality and secrete much more extracel-lular matrix.It is concluded that the RWHMB combines the advantages of the rotating wall vessel and hollow-fiber membrane bioreactors.The hydrodynamic stimulation within it accelerates the metabolism of the osteoblast and mass transfer,which is propitious to cell differenti-ation and proliferation.展开更多
基金Project supported by the National Natural Science Foundation of China(Grant No.21676041)
文摘Tile expressions of interface flee energy （IFE） of composite droplets with meniscal liquid-air interlhce in metastable state on nlicro/nano textured snrfaces were formulated. Then tile parameters to describe the meniscus were determined based on the principle of minimtun 1FE. Furthermore, the IFE barriers and the necessary and sufficient conditions of drop wetting transition fl＇om Cassie to Wenzel were analyzed and the corresponding criteria were lk^rmulated. The results show that the liquid-air interface below a composite droplet is fiat when the post pitches are relatively small, but in a shape of curved meniscus when the piteches are comparatively large and the curvature depends on structural parameters. The angle between meniscus and pillar wall is just equal to the supplementary angle of intrinsic contact angle of post material. The calculations also illustrate that Cassie droplets will transform to Wenzel state when post pitch is large enough or when drop volume is sufficiently small. The opposite transition from Wenzel to Cassie state, however, is unable to take place spontaneously because the energy barrier is always positive. Finally, the calculation results of this model are well consistent with tile experimental obserwttions in literatures for the wetting transition of droplets from Cassie to Wenzel state.
基金supported by the National Natural Science Foundation of China(21872001,51801006,21805004,and 21671011)Beijing Municipal High Level Innovative Team Building Program(IDHT20180504)+2 种基金Beijing Outstanding Young Scientists Program(BJJWZYJH01201910005017)Beijing Natural Science Foundation(2192005)Beijing Municipal Science and Natural Science Fund Project(KM201910005016)。
文摘水体污染是当前造成淡水短缺的主要原因之一.利用太阳能水蒸发装置从海水或污水中生产淡水是一种简单有效且节能的解决淡水危机的方式,引起了广泛的关注.然而,污染物的共同蒸发或沉积可能会降低水蒸发过程中的效率和淡水质量.本文基于天然木质纤维素(NCF)、聚苯胺(PANI)和二氧化钛(TiO_(2))开发了自清洁太阳能水蒸发器,其具有宽吸收、亲水性强、导热系数低等优点.通过在聚合物溶液中加入木质纤维素,聚苯胺纳米纤维在NCF表面聚合形成介孔网络.P25 TiO_(2)纳米颗粒作为光催化剂分散到上述反应液中,通过简单的过滤形成PANI/TiO_(2)/NCF复合材料.由于太阳水蒸发器装置中PANI的光热效应与TiO_(2)纳米颗粒的光催化降解的协同作用,水蒸发速率可达2.36 kg m^(-2)h^(-1)(1个太阳光照射下),且可有效降解污染物(100 ppm四环素).更重要的是,在工作10 h后,该太阳能水蒸发器装置仍然保持稳定的水蒸发速率,且没有污染物的积聚.光催化和光热效应相结合的双功能太阳能水蒸发装置在有机污染物水中具有自清洁作用,具有很大的应用潜力.
文摘Large-scale expansion of the osteoblasts of a Sprague-Dawley(SD)rat was studied in a rotating wall hollow-fiber membrane bioreactor(RWHMB)by using hollow-fiber membrane as the carrier.For the sake of contrast,cells were also expanded in a T-flask using a hollow-fiber membrane as carrier and in a rotating wall vessel bioreactor(RWVB)using a microcarrier.During the culture period,the cells were sampled every 12 h,and after 5 days,the cells were harvested and evaluated with scanning electron microscopy(SEM),hematoxylin-eosin(HE)staining and alkaline phosphatase(ALP)staining.Moreover,von-Kossa staining and Alizarin Red S stain-ing were carried out for mineralized nodules formation.The results show that in RWHMB,the cells present better morphology and vitality and secrete much more extracel-lular matrix.It is concluded that the RWHMB combines the advantages of the rotating wall vessel and hollow-fiber membrane bioreactors.The hydrodynamic stimulation within it accelerates the metabolism of the osteoblast and mass transfer,which is propitious to cell differenti-ation and proliferation.
