Objective: To investigate the causes and preventive measures of pelvic floor peritoneal hernia after transabdominal perineal radical resection of rectal cancer. Patients and Methods: A 68-year-old patient with progres...Objective: To investigate the causes and preventive measures of pelvic floor peritoneal hernia after transabdominal perineal radical resection of rectal cancer. Patients and Methods: A 68-year-old patient with progressive exacerbation of Miles’ postoperative intestinal obstruction was retrospectively analyzed. Conservative treatment was ineffective, and surgery was performed again. Surgery confirmed that the obstruction was caused by a pelvic floor peritoneal hernia. The original reconstruction peritoneal suture needle spacing was too wide, resulting in peritoneal hiatus. Results: The early postoperative intestinal obstruction in this patient was not caused by inflammatory intestinal obstruction, stenosis of stoma, and intestinal adhesion, but by the formation of pelvic floor peritoneal hernia. Conclusion: Pelvic floor peritoneal hernia should not be ignored in the early stage of intestinal obstruction after Miles’ operation. Improper suture during pelvic floor peritoneal reconstruction is the main cause of pelvic floor peritoneal hernia.展开更多
Developing highly active,cost-effective,and environmental friendly oxygen evolution reaction(OER)electrocatalysts facilitates various(photo)electrochemical processes.In this work,Fe3N nanoparticles encapsulated into N...Developing highly active,cost-effective,and environmental friendly oxygen evolution reaction(OER)electrocatalysts facilitates various(photo)electrochemical processes.In this work,Fe3N nanoparticles encapsulated into N-doped graphene nanoshells(Fe_(3)N@NG)as OER electrocatalysts in alkaline media were reported.Both the experimental and theoretical comparison between Fe_(3) N@NG and Fe_(3)N/NG,specifically including in situ Mossbauer analyses,demonstrated that the NG nanoshells improved interfacial electron transfer process from Fe_(3)N to NG to form high-valence Fe^(4+)ions(Fe^(4+)@NG),thus modifying electronic properties of the outer NG shells and subsequently electron transfer from oxygen intermediate to NG nanoshells for OER catalytic process.Meanwhile,the NG nanoshells also protected Fe-based cores from forming OER inactive and insulated Fe_(2)O_(3),leading to high OER stability.As a result,the as-formed Fe^(4+)@NG shows one of the highest electrocatalytic efficiency among reported Fe-based OER electrocatalysts,which can as well highly improve the photoelectrochemical water oxidation when used as the cocatalysts for the Fe_(2)O_(3) nanoarray photoanode.展开更多
Despite the benefits of EHRs (Electronic Health Records), there is a growing concern over the risks of privacy exposure associated with the technologies of EHR storing and transmission. To deal with this problem, a ti...Despite the benefits of EHRs (Electronic Health Records), there is a growing concern over the risks of privacy exposure associated with the technologies of EHR storing and transmission. To deal with this problem, a timeaware searchable encryption with designated server is proposed in this paper. It is based on Boneh's public key encryption with keyword search and Rivest's timed-release cryptology. Our construction has three features: the user cannot issue a keyword search query successfully unless the search falls into the specific time range;only the authorized user can generate a valid trapdoor;only the designated server can execute the search. Applying our scheme in a multi-user environment, the number of the keyword ciphertexts would not increase linearly with the number of the authorized users. The security and performance analysis shows that our proposed scheme is securer and more efficient than the existing similar schemes.展开更多
Electrochemical treatment is a popular and efficient method for improving the photoelectrochemical performance of water‐splitting photoelectrodes.In our previous study,the electrochemical activation of Mo‐doped BiVO...Electrochemical treatment is a popular and efficient method for improving the photoelectrochemical performance of water‐splitting photoelectrodes.In our previous study,the electrochemical activation of Mo‐doped BiVO_(4) electrodes was ascribed to the removal of MoO_(x) segregations,which are considered to be surface recombination centers for photoinduced electrons and holes.However,this proposed mechanism cannot explain why activated Mo‐doped BiVO_(4) electrodes gradually lose their activity when exposed to air.In this study,based on various characterizations,it is suggested that electrochemical treatment not only removes partial MoO_(x) segregations but also initiates the formation of H_(y)MoO_(x) surface defects,which provide charge transfer channels for photogenerated holes.The charge separation of the Mo‐doped BiVO_(4) electrode was significantly enhanced by these charge transfer channels.This study offers a new insight into the electrochemical activation of Mo‐doped BiVO_(4) photoanodes,and the new concept of surface charge transfer channels,a long overlooked factor,will be valuable for the development of other(photo)electrocatalytic systems.展开更多
Space exploration has become a major focus in the field of technology,with gear transmissions in aerospace equipment playing a crucial role.In the extreme environment of space,gear transmissions face challenges like l...Space exploration has become a major focus in the field of technology,with gear transmissions in aerospace equipment playing a crucial role.In the extreme environment of space,gear transmissions face challenges like large temperature differentials,deformation and maintenance difficulties,which will severely impact transmission accuracy and service life.To meet the growing demands for high-performance gear transmissions with high transmission efficiency and error adaptability in the aerospace field,this paper proposes a novel curve-surface conjugate internal gear drive consisting of an involute internal gear and a curve-surface gear.The fundamental theory of curve-surface conjugation is introduced,and the construction method for curve-surface gear based on a selected contact path and meshing tube is presented.The analysis models including induced curvature,sliding ratio and tooth contact analysis with errors(ETCA)are simulated to evaluate the meshing characteristics.Additionally,prototypes are manufactured and experimental setups are established to validate the transmission performance.These results indicate that as the rotational speed increases,the transmission efficiency of the curve-surface conjugate internal gear drive improves,which is contrary to the trend observed in involute gear drives.And the transmission efficiency of the curve-surface conjugate internal gear drive surpasses that of the involute gear drive at higher rotational speeds.Moreover,this novel gear drive exhibits excellent error adaptability,maintaining intact contact paths and high transmission efficiency even in the presence of assembly errors.This study provides new ideas for the design and manufacture of high-performance gear transmissions from the perspective of spatial geometric elements.展开更多
Photoelectrochemical water splitting can convert solar energy into clean hydrogen energy for storage.It is desirable to explore non-precious electrocatalysts for practical applications of a photoelectrode in a large s...Photoelectrochemical water splitting can convert solar energy into clean hydrogen energy for storage.It is desirable to explore non-precious electrocatalysts for practical applications of a photoelectrode in a large scale.Here,we developed a facile spin-coating and in-situ photoelectrochemical reduction method to prepare a dispersed Cu electrocatalyst on a Si photocathode,which improves the performance remarkably.We find that thiourea in the precursor solution for spin-coating plays an important role in obtaining dispersed Cu particles on the surface of a Si photoelectrode.With thiourea in the precursor,the Cu/Si photocathode shows higher performance than the one without thiourea.Moreover,the Cu/Si photocathode also indicates good stability after 16 h illumination.展开更多
文摘Objective: To investigate the causes and preventive measures of pelvic floor peritoneal hernia after transabdominal perineal radical resection of rectal cancer. Patients and Methods: A 68-year-old patient with progressive exacerbation of Miles’ postoperative intestinal obstruction was retrospectively analyzed. Conservative treatment was ineffective, and surgery was performed again. Surgery confirmed that the obstruction was caused by a pelvic floor peritoneal hernia. The original reconstruction peritoneal suture needle spacing was too wide, resulting in peritoneal hiatus. Results: The early postoperative intestinal obstruction in this patient was not caused by inflammatory intestinal obstruction, stenosis of stoma, and intestinal adhesion, but by the formation of pelvic floor peritoneal hernia. Conclusion: Pelvic floor peritoneal hernia should not be ignored in the early stage of intestinal obstruction after Miles’ operation. Improper suture during pelvic floor peritoneal reconstruction is the main cause of pelvic floor peritoneal hernia.
基金supported primarily by the National Key Research and Development Program of China(2018YFE0208500)the Major Research Plan of the National Natural Science Foundation of China(91963206)+4 种基金the National Natural Science Foundation of China(U1508202,51627810,51972164)the Natural Science Foundation of Jiangsu Province(SBK2018022120)the open fund of Wuhan National Laboratory for Optoelectronics(2018WNLOKF020)the open fund of Jiangsu Key Laboratory of Electrochemical Energy Storage Technologies(EEST2018-1)the civil aerospace technology preliminary research project of the State Administration of Science,Technology and Industry for National Defense。
文摘Developing highly active,cost-effective,and environmental friendly oxygen evolution reaction(OER)electrocatalysts facilitates various(photo)electrochemical processes.In this work,Fe3N nanoparticles encapsulated into N-doped graphene nanoshells(Fe_(3)N@NG)as OER electrocatalysts in alkaline media were reported.Both the experimental and theoretical comparison between Fe_(3) N@NG and Fe_(3)N/NG,specifically including in situ Mossbauer analyses,demonstrated that the NG nanoshells improved interfacial electron transfer process from Fe_(3)N to NG to form high-valence Fe^(4+)ions(Fe^(4+)@NG),thus modifying electronic properties of the outer NG shells and subsequently electron transfer from oxygen intermediate to NG nanoshells for OER catalytic process.Meanwhile,the NG nanoshells also protected Fe-based cores from forming OER inactive and insulated Fe_(2)O_(3),leading to high OER stability.As a result,the as-formed Fe^(4+)@NG shows one of the highest electrocatalytic efficiency among reported Fe-based OER electrocatalysts,which can as well highly improve the photoelectrochemical water oxidation when used as the cocatalysts for the Fe_(2)O_(3) nanoarray photoanode.
基金This study was jointly supported by the National Natural Science Foundation of China (No. 61702067, No. 61472464)the Natural Science Foundation of Shangdong Province, China (No. ZR2015FL024).
文摘Despite the benefits of EHRs (Electronic Health Records), there is a growing concern over the risks of privacy exposure associated with the technologies of EHR storing and transmission. To deal with this problem, a timeaware searchable encryption with designated server is proposed in this paper. It is based on Boneh's public key encryption with keyword search and Rivest's timed-release cryptology. Our construction has three features: the user cannot issue a keyword search query successfully unless the search falls into the specific time range;only the authorized user can generate a valid trapdoor;only the designated server can execute the search. Applying our scheme in a multi-user environment, the number of the keyword ciphertexts would not increase linearly with the number of the authorized users. The security and performance analysis shows that our proposed scheme is securer and more efficient than the existing similar schemes.
文摘Electrochemical treatment is a popular and efficient method for improving the photoelectrochemical performance of water‐splitting photoelectrodes.In our previous study,the electrochemical activation of Mo‐doped BiVO_(4) electrodes was ascribed to the removal of MoO_(x) segregations,which are considered to be surface recombination centers for photoinduced electrons and holes.However,this proposed mechanism cannot explain why activated Mo‐doped BiVO_(4) electrodes gradually lose their activity when exposed to air.In this study,based on various characterizations,it is suggested that electrochemical treatment not only removes partial MoO_(x) segregations but also initiates the formation of H_(y)MoO_(x) surface defects,which provide charge transfer channels for photogenerated holes.The charge separation of the Mo‐doped BiVO_(4) electrode was significantly enhanced by these charge transfer channels.This study offers a new insight into the electrochemical activation of Mo‐doped BiVO_(4) photoanodes,and the new concept of surface charge transfer channels,a long overlooked factor,will be valuable for the development of other(photo)electrocatalytic systems.
基金Supported by Major Projects in Aviation Engines and Gas Turbines(Grant No.J2019-IV-0001-0068).
文摘Space exploration has become a major focus in the field of technology,with gear transmissions in aerospace equipment playing a crucial role.In the extreme environment of space,gear transmissions face challenges like large temperature differentials,deformation and maintenance difficulties,which will severely impact transmission accuracy and service life.To meet the growing demands for high-performance gear transmissions with high transmission efficiency and error adaptability in the aerospace field,this paper proposes a novel curve-surface conjugate internal gear drive consisting of an involute internal gear and a curve-surface gear.The fundamental theory of curve-surface conjugation is introduced,and the construction method for curve-surface gear based on a selected contact path and meshing tube is presented.The analysis models including induced curvature,sliding ratio and tooth contact analysis with errors(ETCA)are simulated to evaluate the meshing characteristics.Additionally,prototypes are manufactured and experimental setups are established to validate the transmission performance.These results indicate that as the rotational speed increases,the transmission efficiency of the curve-surface conjugate internal gear drive improves,which is contrary to the trend observed in involute gear drives.And the transmission efficiency of the curve-surface conjugate internal gear drive surpasses that of the involute gear drive at higher rotational speeds.Moreover,this novel gear drive exhibits excellent error adaptability,maintaining intact contact paths and high transmission efficiency even in the presence of assembly errors.This study provides new ideas for the design and manufacture of high-performance gear transmissions from the perspective of spatial geometric elements.
基金supported by the International S&T Cooperation Program of China (2017YFE0120700)the National Natural Science foundation of China (21875105, 61674097)+1 种基金the National Scientific Instrument Develop Major Project of National Natural Science Foundation of China (51627810)the advanced research program of Education Institute of Jiangsu Province (PPZY2015A033)
文摘Photoelectrochemical water splitting can convert solar energy into clean hydrogen energy for storage.It is desirable to explore non-precious electrocatalysts for practical applications of a photoelectrode in a large scale.Here,we developed a facile spin-coating and in-situ photoelectrochemical reduction method to prepare a dispersed Cu electrocatalyst on a Si photocathode,which improves the performance remarkably.We find that thiourea in the precursor solution for spin-coating plays an important role in obtaining dispersed Cu particles on the surface of a Si photoelectrode.With thiourea in the precursor,the Cu/Si photocathode shows higher performance than the one without thiourea.Moreover,the Cu/Si photocathode also indicates good stability after 16 h illumination.
