Composites derived from metal-organic frameworks(MOFs)show promise as catalysts for the photocat-alytic reduction of CO_(2).However,their potential is hindered by constraints such as limited light absorp-tion and slug...Composites derived from metal-organic frameworks(MOFs)show promise as catalysts for the photocat-alytic reduction of CO_(2).However,their potential is hindered by constraints such as limited light absorp-tion and sluggish electron transfer and separation,impacting the overall efficiency of the photocatalytic process.In this study,TiO_(2)nanocrystals,modified with Ptx+,underwent laser etching were encapsulated within the traditional MOF-ZIF-8 framework.This enhanced the adsorption capabilities for CO_(2)reactants and solar light,while also facilitating directed electron transfer and the separation of photogenerated charges.The finely-tuned catalyst demonstrates impressive CH_(4) selectivity at 9.5%,with yields of 250.24μmol g^(-1)h^(-1)for CO and 25.43μmol g^(-1)h^(-1)for CH_(4),utilizing water as a hole trap and H^(+)source.This study demonstrates the viability of achieving characteristics related to the separation of photogen-erated charges in TiO_(2)nanocrystals through laser etching and MOF composite catalysts.It offers novel perspectives for designing MOF-based catalysts with enhanced performance in artificial photosynthesis.展开更多
A web service wrapping approach for command line programs,which are commonly used in scientific computing,is proposed.First,software architecture for a basic web service wrapper implementation is given and the functio...A web service wrapping approach for command line programs,which are commonly used in scientific computing,is proposed.First,software architecture for a basic web service wrapper implementation is given and the functions of the main components are explained.Then after a comprehensive analysis of data transmission and a job life cycle model,a novel proactive file transmission and job management mechanism is devised to enhance the software architecture,and the command line programs are wrapped into web services in such a way that they can efficiently transmit files,supply instant status feedback and automatically manage the jobs.Experiments show that the proposed approach achieves higher performance with less memory usage compared to the related work, and the usability is also improved.This work has already been put into use in a production system of scientific computing and the data processing efficiency of the system is greatly improved.展开更多
In specific condition, when wrapping angle of cold rolling strip covering surface of shape detecting roll dynamically changes, online radial compression of the shape detecting roll is changed too, and it seriously aff...In specific condition, when wrapping angle of cold rolling strip covering surface of shape detecting roll dynamically changes, online radial compression of the shape detecting roll is changed too, and it seriously affects online shape detecting precision of cold strip. Based on the latest intelligent shape meter developed by Yanshan University, using PSO-BP neural network and actual working condition datum, the cold strip online dynamic wrapping angle compensation model is established, and successfully applied in 1250 mm 6-high cold mill, remarkable results are achieved. The error between calculated values and measured values of total tensions is within 3 %展开更多
Objective： After pancreaticoduodenectomy （PD）, the postoperative gastroduodenal artery stump （GDAS） hemorrhage is one of the most serious complications. The purpose of this study is to determine whether wrapping ...Objective： After pancreaticoduodenectomy （PD）, the postoperative gastroduodenal artery stump （GDAS） hemorrhage is one of the most serious complications. The purpose of this study is to determine whether wrapping the GDAS during PD could decrease the postoperative GDAS hemorrhage incidence. Methods： A retrospective review involving 280 patients who underwent PD from 2005 to 2012 was performed. Wrapping the GDAS during PD was defined as ＂Wrapping the GDAS using the teres hepatis ligamentum during PD＂. A total of 140 patients accepted the ＂wrapping＂ procedure （wrapping group）. The other 140 patients didn＇t apply the procedure （non-wrapping group）. Age, sex, preoperative data, estimated intraoperative blood loss, postoperative complications, pathologic parameters and hospitalization time were compared between two groups. ResultsI There were no significant differences in patient characteristics between two groups. After wrapping, the incidence of postoperative GDAS bleeding decreased significantly （1/140 vs. 9/140, P=0.01）. The rates of the other complications （such as intra-abdominal infection pancreatic fistula, billiary fistula, gastrointestinal bleeding, et aL） showed no significant differences. Conclusions： Wrapping the GDAS during PD significantly reduced the postoperative GDAS hemorrhage incidence. And the ＂wrapping＂ had no obvious influence on other complications.展开更多
AIM: To retrospectively compare postoperative outcomes after primary enucleation and placement of a hydroxyapatite(HA) implant without wrapping, wrapped with auricular cartilage or donor sclera. METHODS: Medical recor...AIM: To retrospectively compare postoperative outcomes after primary enucleation and placement of a hydroxyapatite(HA) implant without wrapping, wrapped with auricular cartilage or donor sclera. METHODS: Medical records of patients presented as intraocular tumor or severe ocular injury were identified from the electronic medical record system. Cases underwent enucleation and HA orbital implantation were enrolled in this study and were divided into 3 groups according to the wrapping material of HA implant. Cases with autogenous cartilage caps were enrolled in group A(n=11), with donor sclera caps in group B(n=12), and without any wrapping material in group C(n=9). Follow-ups were set at 1, 2 wk, 1, 3, 6, and 12 mo after surgery.RESULTS: Altogether 32 cases finished the followup and were enrolled in this study. Three cases(27.27%) in group A, 4 cases(33.33%) in group B, and 4 cases(44.44%) in group C developed one complication each after surgery. In group A, no HA exposure occurred, but conjunctival inclusion cyst occurred in one and severe conjunctive chemosis in two cases. In group B, one HA exposure occurred, conjunctive inclusion cysts occurred in one, severe conjunctive chemosis occurred in one, and conjunctival granuloma occurred in one case. In group C, one HA exposure occurred, severe conjunctive chemosis occurred in two cases, and conjunctival granuloma occurred in one case. The case of exposure of none-wrapped implant was noted in the first 6 mo after placement of the orbital implant. The case of exposure of donor sclerawrapped implant was noted at the 12 mo after placement of the orbital implant. Both exposure cases were treated successfully with conservative treatment.CONCLUSION: With low incidence of implant exposure and mild complications, auricular cartilage can be a good choice of alternative wrapping material of orbit implant with satisfied outcome.展开更多
A novel multi-baseline phase unwrapping algorithm based on the unscented particle filter for interferometric synthetic aperture radar （INSAR） technology application is proposed. The proposed method is not constraine...A novel multi-baseline phase unwrapping algorithm based on the unscented particle filter for interferometric synthetic aperture radar （INSAR） technology application is proposed. The proposed method is not constrained by the nonlinearity of the problem and is independent of noise statistics, and performs noise eliminating and phase unwrapping at the same time by combining with an unscented particle filter with a path-following strategy and an omni-directional local phase slope estimator. Results obtained from multi-baseline synthetic data and single-baseline real data show the performance of the proposed method.展开更多
Currently,data security mainly relies on password(PW)or system channel key(SKCH)to encrypt data before they are sent,no matter whether in broadband networks,the 5th generation(5G)mobile communications,satellite commun...Currently,data security mainly relies on password(PW)or system channel key(SKCH)to encrypt data before they are sent,no matter whether in broadband networks,the 5th generation(5G)mobile communications,satellite communications,and so on.In these environments,a fixed password or channel key(e.g.,PW/SKCH)is often adopted to encrypt different data,resulting in security risks since thisPW/SKCH may be solved after hackers collect a huge amount of encrypted data.Actually,the most popularly used security mechanism Advanced Encryption Standard(AES)has its own problems,e.g.,several rounds have been solved.On the other hand,if data protected by the same PW/SKCH at different time points can derive different data encryption parameters,the system’s security level will be then greatly enhanced.Therefore,in this study,a security scheme,named Wrapping Encryption Based on Double Randomness Mechanism(WEBDR),is proposed by integrating a password key(or a system channel key)and an Initialization Vector(IV)to generate an Initial Encryption Key(IEK).Also,an Accumulated Shifting Substitution(ASS)function and a three-dimensional encryption method are adopted to produce a set of keys.Two randomness encryption mechanisms are developed.The first generates system sub-keys and calculates the length of the first pseudo-random numbers by employing IEK for providing subsequent encryption/decryption.The second produces a random encryption key and a sequence of internal feedback codes and computes the length of the second pseudo-random numbers for encrypting delivered messages.A wrapped mechanism is further utilized to pack a ciphertext file so that a wrapped ciphertext file,rather than the ciphertext,will be produced and then transmitted to its destination.The findings are as follows.Our theoretic analyses and simulations demonstrate that the security of the WEBDR in cloud communication has achieved its practical security.Also,AES requires 176 times exclusive OR(XOR)operations for both encryption and decryption,while the WEBDR consumes only 3 operations.That is why the WEBDR is 6.7∼7.09 times faster than the AES,thus more suitable for replacing the AES to protect data transmitted between a cloud system and its users.展开更多
Specific to problems of the existing round bale wrapping machine in China,such as small application scope and failing to satisfy the wrapping demands of round bales of different specifications,a tumbler-type round bal...Specific to problems of the existing round bale wrapping machine in China,such as small application scope and failing to satisfy the wrapping demands of round bales of different specifications,a tumbler-type round bale wrapping machine based on wrapping silage with stretch film was designed.By theoretical analysis and preliminary experiments of the corresponding wrapping process,revolving speed of tumbler,speed ratio between tumbler and carrier rollers,and pre-load force of stretch film were determined as experimental factors,while wrapping time and consumption of stretch film per unit mass of round bale were determined as evaluation indexes.Furthermore,quadratic regression orthogonal rotational combination experimental design was adopted to carry out the wrapping experiment.The regression models were set up,and influencing rules of experimental factors on evaluation indexes were also analyzed.The optimal parameter combination scheme was revolving speed of tumbler of 31-32 r/min,speed ratio between tumbler and carrier rollers of 2.6,and pre-load force of stretch film of 20-22 N.Under such a circumstance,the corresponding wrapping time required was 37.7-38.9 s and consumption of stretch film per unit mass of round bale was 3.21-3.46 kg/t.The predicted values and the measured values of evaluation indexes basically coincided with each other and the relative error fell below 5%,which indicated that both the optimized regression models acquired through the wrapping experiment and the relevant parameter optimization results were reliable.To guarantee the quality of rice straw silage,the round bale should be wrapped by no less than five layers of stretch films through the utilization of the tumbler-type round bale wrapping machine.The study results could be used as references for research and development of the round bale wrapping machine.展开更多
Axonal regeneration following surgical nerve repair is slow and often incomplete,resulting in poor functional recovery which sometimes contributes to lifelong disability.Currently,there are no FDA-approved therapies a...Axonal regeneration following surgical nerve repair is slow and often incomplete,resulting in poor functional recovery which sometimes contributes to lifelong disability.Currently,there are no FDA-approved therapies available to promote nerve regeneration.Tacrolimus accelerates axonal regeneration,but systemic side effects presently outweigh its potential benefits for peripheral nerve surgery.The authors describe herein a biodegradable polyurethane-based drug delivery system for the sustained local release of tacrolimus at the nerve repair site,with suitable properties for scalable production and clinical application,aiming to promote nerve regeneration and functional recovery with minimal systemic drug exposure.Tacrolimus is encapsulated into co-axially electrospun polycarbonate-urethane nanofibers to generate an implantable nerve wrap that releases therapeutic doses of bioactive tacrolimus over 31 days.Size and drug loading are adjustable for applications in small and large caliber nerves,and the wrap degrades within 120 days into biocompatible byproducts.Tacrolimus released from the nerve wrap promotes axon elongation in vitro and accelerates nerve regeneration and functional recovery in preclinical nerve repair models while off-target systemic drug exposure is reduced by 80%compared with systemic delivery.Given its surgical suitability and preclinical efficacy and safety,this system may provide a readily translatable approach to support axonal regeneration and recovery in patients undergoing nerve surgery.展开更多
Cu with and without La addition was prepared and the effect of a trace amount of La on the arc erosion behaviors and oxidation resistance of Cu alloys was investigated. The results indicate that CuLa alloy exhibits su...Cu with and without La addition was prepared and the effect of a trace amount of La on the arc erosion behaviors and oxidation resistance of Cu alloys was investigated. The results indicate that CuLa alloy exhibits superior oxidation resistance and arc erosion resistance. The contact resistance and temperature rise were obviously improved. The oxidation resistance of CuLa alloy mainly is due to the interface wrapping of La2O3 particles and CuLa alloy phase on Cu atoms. Thermodynamic calculation indicated that La2O3 could form preferentially in the CuLa alloy, which was beneficial for the protection of the Cu substrate. According to kinetics analysis, the activation energy of CuLa alloy was higher than that of pure Cu, indicating the better oxidation resistance of CuLa alloys.展开更多
Graphene-metal based materials have been utilized in lithium-sulfur(Li–S)batteries owing to their integrated functionalities thus far.However,their synthesis has predominantly relied on wet-chemistry routes,which lim...Graphene-metal based materials have been utilized in lithium-sulfur(Li–S)batteries owing to their integrated functionalities thus far.However,their synthesis has predominantly relied on wet-chemistry routes,which limited their practical activity in Li–S reaction systems.In this study,we introduce a chemical vapor deposition(CVD)-triggered dry-chemistry approach for the preparation of graphene-cobalt(Co)based catalysts.The versatile CVD technique provides a dry and controllable reaction environment,effectively pledging the compact and clean catalytic interfaces between graphene and Co-based components.Additionally,programmed reactions introduce defects such as vacancies and nitrogen heteroatoms into the catalysts.Notably,the graphene layer number and Co valence state can be delicately manipulated by altering the CVD reaction temperature.Specifically,few-layer graphene wrapped Co/Co_(3)O_(4)(FGr-Co/Co_(3)O_(4))prepared at 450 ℃ shows higher catalytic activity than the multi-layer graphene wrapped Co/CoO(MGr-Co/CoO)synthesized at 550 ℃,attributed to its comprehensive control of clean interface,valence distribution range and defects.Leveraging these advantages,the battery with FGr-Co/Co_(3)O_(4)shows favorable working stability with a degradation rate of only 0.08%over 500 cycles at 1.0 C.Furthermore,under an elevated sulfur loading of 6.1 mg cm^(–2),the battery harvests a remarkable areal capacity of 5.9 mA h cm^(–2)along with stable cyclic operation.展开更多
文摘Composites derived from metal-organic frameworks(MOFs)show promise as catalysts for the photocat-alytic reduction of CO_(2).However,their potential is hindered by constraints such as limited light absorp-tion and sluggish electron transfer and separation,impacting the overall efficiency of the photocatalytic process.In this study,TiO_(2)nanocrystals,modified with Ptx+,underwent laser etching were encapsulated within the traditional MOF-ZIF-8 framework.This enhanced the adsorption capabilities for CO_(2)reactants and solar light,while also facilitating directed electron transfer and the separation of photogenerated charges.The finely-tuned catalyst demonstrates impressive CH_(4) selectivity at 9.5%,with yields of 250.24μmol g^(-1)h^(-1)for CO and 25.43μmol g^(-1)h^(-1)for CH_(4),utilizing water as a hole trap and H^(+)source.This study demonstrates the viability of achieving characteristics related to the separation of photogen-erated charges in TiO_(2)nanocrystals through laser etching and MOF composite catalysts.It offers novel perspectives for designing MOF-based catalysts with enhanced performance in artificial photosynthesis.
基金The National Natural Science Foundation of China(No.60573117)the National Basic Research Program of China(973 Program)(No.2007CB310805)
文摘A web service wrapping approach for command line programs,which are commonly used in scientific computing,is proposed.First,software architecture for a basic web service wrapper implementation is given and the functions of the main components are explained.Then after a comprehensive analysis of data transmission and a job life cycle model,a novel proactive file transmission and job management mechanism is devised to enhance the software architecture,and the command line programs are wrapped into web services in such a way that they can efficiently transmit files,supply instant status feedback and automatically manage the jobs.Experiments show that the proposed approach achieves higher performance with less memory usage compared to the related work, and the usability is also improved.This work has already been put into use in a production system of scientific computing and the data processing efficiency of the system is greatly improved.
基金Item Sponsored by National Science and Technology Support Plan of China(2007BAF02B10)Natural Science Foundation of Hebei Province of China(E2011203004)
文摘In specific condition, when wrapping angle of cold rolling strip covering surface of shape detecting roll dynamically changes, online radial compression of the shape detecting roll is changed too, and it seriously affects online shape detecting precision of cold strip. Based on the latest intelligent shape meter developed by Yanshan University, using PSO-BP neural network and actual working condition datum, the cold strip online dynamic wrapping angle compensation model is established, and successfully applied in 1250 mm 6-high cold mill, remarkable results are achieved. The error between calculated values and measured values of total tensions is within 3 %
基金funded by A new round of the Shanghai Health System outstanding young talent training plan (XYQ2011030)
文摘Objective： After pancreaticoduodenectomy （PD）, the postoperative gastroduodenal artery stump （GDAS） hemorrhage is one of the most serious complications. The purpose of this study is to determine whether wrapping the GDAS during PD could decrease the postoperative GDAS hemorrhage incidence. Methods： A retrospective review involving 280 patients who underwent PD from 2005 to 2012 was performed. Wrapping the GDAS during PD was defined as ＂Wrapping the GDAS using the teres hepatis ligamentum during PD＂. A total of 140 patients accepted the ＂wrapping＂ procedure （wrapping group）. The other 140 patients didn＇t apply the procedure （non-wrapping group）. Age, sex, preoperative data, estimated intraoperative blood loss, postoperative complications, pathologic parameters and hospitalization time were compared between two groups. ResultsI There were no significant differences in patient characteristics between two groups. After wrapping, the incidence of postoperative GDAS bleeding decreased significantly （1/140 vs. 9/140, P=0.01）. The rates of the other complications （such as intra-abdominal infection pancreatic fistula, billiary fistula, gastrointestinal bleeding, et aL） showed no significant differences. Conclusions： Wrapping the GDAS during PD significantly reduced the postoperative GDAS hemorrhage incidence. And the ＂wrapping＂ had no obvious influence on other complications.
文摘AIM: To retrospectively compare postoperative outcomes after primary enucleation and placement of a hydroxyapatite(HA) implant without wrapping, wrapped with auricular cartilage or donor sclera. METHODS: Medical records of patients presented as intraocular tumor or severe ocular injury were identified from the electronic medical record system. Cases underwent enucleation and HA orbital implantation were enrolled in this study and were divided into 3 groups according to the wrapping material of HA implant. Cases with autogenous cartilage caps were enrolled in group A(n=11), with donor sclera caps in group B(n=12), and without any wrapping material in group C(n=9). Follow-ups were set at 1, 2 wk, 1, 3, 6, and 12 mo after surgery.RESULTS: Altogether 32 cases finished the followup and were enrolled in this study. Three cases(27.27%) in group A, 4 cases(33.33%) in group B, and 4 cases(44.44%) in group C developed one complication each after surgery. In group A, no HA exposure occurred, but conjunctival inclusion cyst occurred in one and severe conjunctive chemosis in two cases. In group B, one HA exposure occurred, conjunctive inclusion cysts occurred in one, severe conjunctive chemosis occurred in one, and conjunctival granuloma occurred in one case. In group C, one HA exposure occurred, severe conjunctive chemosis occurred in two cases, and conjunctival granuloma occurred in one case. The case of exposure of none-wrapped implant was noted in the first 6 mo after placement of the orbital implant. The case of exposure of donor sclerawrapped implant was noted at the 12 mo after placement of the orbital implant. Both exposure cases were treated successfully with conservative treatment.CONCLUSION: With low incidence of implant exposure and mild complications, auricular cartilage can be a good choice of alternative wrapping material of orbit implant with satisfied outcome.
基金supported by the National Natural Science Foundation of China(41201479)the Scientific Research Project of Guilin University of Electronic Technology(UF11015Y)
文摘A novel multi-baseline phase unwrapping algorithm based on the unscented particle filter for interferometric synthetic aperture radar （INSAR） technology application is proposed. The proposed method is not constrained by the nonlinearity of the problem and is independent of noise statistics, and performs noise eliminating and phase unwrapping at the same time by combining with an unscented particle filter with a path-following strategy and an omni-directional local phase slope estimator. Results obtained from multi-baseline synthetic data and single-baseline real data show the performance of the proposed method.
基金supported in part by Ministry of Science and Technology(MOST),Taiwan under the Grant MOST 109-2221-E-029-017-MY2.
文摘Currently,data security mainly relies on password(PW)or system channel key(SKCH)to encrypt data before they are sent,no matter whether in broadband networks,the 5th generation(5G)mobile communications,satellite communications,and so on.In these environments,a fixed password or channel key(e.g.,PW/SKCH)is often adopted to encrypt different data,resulting in security risks since thisPW/SKCH may be solved after hackers collect a huge amount of encrypted data.Actually,the most popularly used security mechanism Advanced Encryption Standard(AES)has its own problems,e.g.,several rounds have been solved.On the other hand,if data protected by the same PW/SKCH at different time points can derive different data encryption parameters,the system’s security level will be then greatly enhanced.Therefore,in this study,a security scheme,named Wrapping Encryption Based on Double Randomness Mechanism(WEBDR),is proposed by integrating a password key(or a system channel key)and an Initialization Vector(IV)to generate an Initial Encryption Key(IEK).Also,an Accumulated Shifting Substitution(ASS)function and a three-dimensional encryption method are adopted to produce a set of keys.Two randomness encryption mechanisms are developed.The first generates system sub-keys and calculates the length of the first pseudo-random numbers by employing IEK for providing subsequent encryption/decryption.The second produces a random encryption key and a sequence of internal feedback codes and computes the length of the second pseudo-random numbers for encrypting delivered messages.A wrapped mechanism is further utilized to pack a ciphertext file so that a wrapped ciphertext file,rather than the ciphertext,will be produced and then transmitted to its destination.The findings are as follows.Our theoretic analyses and simulations demonstrate that the security of the WEBDR in cloud communication has achieved its practical security.Also,AES requires 176 times exclusive OR(XOR)operations for both encryption and decryption,while the WEBDR consumes only 3 operations.That is why the WEBDR is 6.7∼7.09 times faster than the AES,thus more suitable for replacing the AES to protect data transmitted between a cloud system and its users.
基金The authors acknowledge that this work was financially supported by the National Natural Science Foundation of China(Grant No.51405076)the 13th Five Years Key Programs for Science and Technology Development of China(Grant No.2016YFD0701300).
文摘Specific to problems of the existing round bale wrapping machine in China,such as small application scope and failing to satisfy the wrapping demands of round bales of different specifications,a tumbler-type round bale wrapping machine based on wrapping silage with stretch film was designed.By theoretical analysis and preliminary experiments of the corresponding wrapping process,revolving speed of tumbler,speed ratio between tumbler and carrier rollers,and pre-load force of stretch film were determined as experimental factors,while wrapping time and consumption of stretch film per unit mass of round bale were determined as evaluation indexes.Furthermore,quadratic regression orthogonal rotational combination experimental design was adopted to carry out the wrapping experiment.The regression models were set up,and influencing rules of experimental factors on evaluation indexes were also analyzed.The optimal parameter combination scheme was revolving speed of tumbler of 31-32 r/min,speed ratio between tumbler and carrier rollers of 2.6,and pre-load force of stretch film of 20-22 N.Under such a circumstance,the corresponding wrapping time required was 37.7-38.9 s and consumption of stretch film per unit mass of round bale was 3.21-3.46 kg/t.The predicted values and the measured values of evaluation indexes basically coincided with each other and the relative error fell below 5%,which indicated that both the optimized regression models acquired through the wrapping experiment and the relevant parameter optimization results were reliable.To guarantee the quality of rice straw silage,the round bale should be wrapped by no less than five layers of stretch films through the utilization of the tumbler-type round bale wrapping machine.The study results could be used as references for research and development of the round bale wrapping machine.
基金supported by the German Research Foundation(DA 2255/1-1to SCD)+4 种基金a SickKids Research Training Competition(RESTRACOMP)Graduate Scholarship(to KJWS)an Ontario Graduate Scholarship(to KJWS)a grant from Natural Sciences and Engineering Research Council of Canada(NSERC)(to KJWS)a Kickstarter grant from the Institute of Biomedical Engineering(BME)at the University of Toronto(to KJWS)the Abe Frank Fund from the Riley’s Children Foundation(GHB)。
文摘Axonal regeneration following surgical nerve repair is slow and often incomplete,resulting in poor functional recovery which sometimes contributes to lifelong disability.Currently,there are no FDA-approved therapies available to promote nerve regeneration.Tacrolimus accelerates axonal regeneration,but systemic side effects presently outweigh its potential benefits for peripheral nerve surgery.The authors describe herein a biodegradable polyurethane-based drug delivery system for the sustained local release of tacrolimus at the nerve repair site,with suitable properties for scalable production and clinical application,aiming to promote nerve regeneration and functional recovery with minimal systemic drug exposure.Tacrolimus is encapsulated into co-axially electrospun polycarbonate-urethane nanofibers to generate an implantable nerve wrap that releases therapeutic doses of bioactive tacrolimus over 31 days.Size and drug loading are adjustable for applications in small and large caliber nerves,and the wrap degrades within 120 days into biocompatible byproducts.Tacrolimus released from the nerve wrap promotes axon elongation in vitro and accelerates nerve regeneration and functional recovery in preclinical nerve repair models while off-target systemic drug exposure is reduced by 80%compared with systemic delivery.Given its surgical suitability and preclinical efficacy and safety,this system may provide a readily translatable approach to support axonal regeneration and recovery in patients undergoing nerve surgery.
基金Project(51171146)supported by the National Natural Science Foundation of China
文摘Cu with and without La addition was prepared and the effect of a trace amount of La on the arc erosion behaviors and oxidation resistance of Cu alloys was investigated. The results indicate that CuLa alloy exhibits superior oxidation resistance and arc erosion resistance. The contact resistance and temperature rise were obviously improved. The oxidation resistance of CuLa alloy mainly is due to the interface wrapping of La2O3 particles and CuLa alloy phase on Cu atoms. Thermodynamic calculation indicated that La2O3 could form preferentially in the CuLa alloy, which was beneficial for the protection of the Cu substrate. According to kinetics analysis, the activation energy of CuLa alloy was higher than that of pure Cu, indicating the better oxidation resistance of CuLa alloys.
基金support of the National Natural Science Foundation of China(Grant No.52172239,52202038,and 52402247)the Innovative Funds Plan of Henan University of Technology(Grant No.2020ZKCJ07)the Natural Science Foundation of Shandong Province(Grant No.ZR2022QE081)。
文摘Graphene-metal based materials have been utilized in lithium-sulfur(Li–S)batteries owing to their integrated functionalities thus far.However,their synthesis has predominantly relied on wet-chemistry routes,which limited their practical activity in Li–S reaction systems.In this study,we introduce a chemical vapor deposition(CVD)-triggered dry-chemistry approach for the preparation of graphene-cobalt(Co)based catalysts.The versatile CVD technique provides a dry and controllable reaction environment,effectively pledging the compact and clean catalytic interfaces between graphene and Co-based components.Additionally,programmed reactions introduce defects such as vacancies and nitrogen heteroatoms into the catalysts.Notably,the graphene layer number and Co valence state can be delicately manipulated by altering the CVD reaction temperature.Specifically,few-layer graphene wrapped Co/Co_(3)O_(4)(FGr-Co/Co_(3)O_(4))prepared at 450 ℃ shows higher catalytic activity than the multi-layer graphene wrapped Co/CoO(MGr-Co/CoO)synthesized at 550 ℃,attributed to its comprehensive control of clean interface,valence distribution range and defects.Leveraging these advantages,the battery with FGr-Co/Co_(3)O_(4)shows favorable working stability with a degradation rate of only 0.08%over 500 cycles at 1.0 C.Furthermore,under an elevated sulfur loading of 6.1 mg cm^(–2),the battery harvests a remarkable areal capacity of 5.9 mA h cm^(–2)along with stable cyclic operation.
