Industrialization has though brought comfort to our daily lives,but it has placed a lot of pressure on the planet’s natural resources,subsequently,it has adversely affected the environment.As the need for cement in t...Industrialization has though brought comfort to our daily lives,but it has placed a lot of pressure on the planet’s natural resources,subsequently,it has adversely affected the environment.As the need for cement in the construction sector has grown,it has climbed dramatically globally.Around the world,more than 10 billion cubic meters of concrete are produced each year;it is doubtful that this volume will decrease.A significant expected rise in CO_(2) emissions is caused by increased cement demand.According to the UN Environment Program,buildings are responsible for up to 41%of global anthropogenic carbon emissions.The primary source of greenhouse gases utilized in the manufacturing of cement is clinker.Due to the unsustainable supply of fly ash,calcined clay appears to be a better Supplemental Cementitious Material(SCMs).Kaolin clay is widely available in Pakistan.The purpose of this investigation is to describe the mineral and thermal characteristics of Pakistani clays by examining their geographic distribution.Clay samples were gathered from 39 different places throughout Pakistan during a field investigation program.X-ray diffraction,X-ray Fluorescence,Reactivity,and thermogravimetric analyses were used to analyze the clay samples’mineral content and thermal characteristics.This study demonstrates that Pakistan has a substantial amount of kaolin clay reserves close to existing groups of cement plants.Pakistani clays can be utilized as SCM in the production of limestone calcined clay cement(LC^(3))due to the country’s vast kaolin clay reserves.This study further supports the viability of producing LC^(3) in the nation by providing a thorough analysis of the cement business,known deposits of qualifying clay,and the country’s cement production process.展开更多
Thermo-responsive shape memory hydrogels generally achieve shape fixation at low temperatures,and shape recovery at high temperatures.However,these hydrogels usually suffer from poor mechanical properties.Herein,we pr...Thermo-responsive shape memory hydrogels generally achieve shape fixation at low temperatures,and shape recovery at high temperatures.However,these hydrogels usually suffer from poor mechanical properties.Herein,we present a unique poly(acrylic acid)/calcium acetate shape memory hydrogel with cold-induced shape recovery performances as ultrastrong artificial muscles.Since the acetate groups could form aggregate at high temperatures and thus induce the association of the hydrogel network,the hydrogel can be fixed into a temporary shape upon heating and recover to its original shape in a cold environment.Moreover,a programmable shape recovery process is realized by adjusting the shape fixing time.In addition,the unique shape memory process enables the application demonstration as bio-inspired artificial muscles with an ultrahigh work density of45.2 kJ m^(-3),higher than that of biological muscles(~8 kJ m^(-3)).展开更多
基金support from China National Key R&D Program‐International Scientific and Technological Innovation Cooperation Key Project(Grant No.:2018YFE0106300)The research was mainly supported by the Higher Education Commission of Pakistan(National Research Program for Universities—NRPU Project No.14074).
文摘Industrialization has though brought comfort to our daily lives,but it has placed a lot of pressure on the planet’s natural resources,subsequently,it has adversely affected the environment.As the need for cement in the construction sector has grown,it has climbed dramatically globally.Around the world,more than 10 billion cubic meters of concrete are produced each year;it is doubtful that this volume will decrease.A significant expected rise in CO_(2) emissions is caused by increased cement demand.According to the UN Environment Program,buildings are responsible for up to 41%of global anthropogenic carbon emissions.The primary source of greenhouse gases utilized in the manufacturing of cement is clinker.Due to the unsustainable supply of fly ash,calcined clay appears to be a better Supplemental Cementitious Material(SCMs).Kaolin clay is widely available in Pakistan.The purpose of this investigation is to describe the mineral and thermal characteristics of Pakistani clays by examining their geographic distribution.Clay samples were gathered from 39 different places throughout Pakistan during a field investigation program.X-ray diffraction,X-ray Fluorescence,Reactivity,and thermogravimetric analyses were used to analyze the clay samples’mineral content and thermal characteristics.This study demonstrates that Pakistan has a substantial amount of kaolin clay reserves close to existing groups of cement plants.Pakistani clays can be utilized as SCM in the production of limestone calcined clay cement(LC^(3))due to the country’s vast kaolin clay reserves.This study further supports the viability of producing LC^(3) in the nation by providing a thorough analysis of the cement business,known deposits of qualifying clay,and the country’s cement production process.
基金supported by the National Natural Science Foundation of China(51873223 and 22075154)the Natural Science Foundation of Zhejiang Province(LY19B040001)。
文摘Thermo-responsive shape memory hydrogels generally achieve shape fixation at low temperatures,and shape recovery at high temperatures.However,these hydrogels usually suffer from poor mechanical properties.Herein,we present a unique poly(acrylic acid)/calcium acetate shape memory hydrogel with cold-induced shape recovery performances as ultrastrong artificial muscles.Since the acetate groups could form aggregate at high temperatures and thus induce the association of the hydrogel network,the hydrogel can be fixed into a temporary shape upon heating and recover to its original shape in a cold environment.Moreover,a programmable shape recovery process is realized by adjusting the shape fixing time.In addition,the unique shape memory process enables the application demonstration as bio-inspired artificial muscles with an ultrahigh work density of45.2 kJ m^(-3),higher than that of biological muscles(~8 kJ m^(-3)).
