Desertification creeps across the landscape like a silent thief,stealing life and leaving behind a barren wasteland.This year's World Environment Day theme,‘Land Restoration,desertification and drought resilience...Desertification creeps across the landscape like a silent thief,stealing life and leaving behind a barren wasteland.This year's World Environment Day theme,‘Land Restoration,desertification and drought resilience’,is a stark reminder of the pressing need to heal the wounds we've inflicted on our planet.展开更多
By establishing the concepts of fuzzy approaching set and fuzzy approaching functional mapping and making research on them, a new method for time series prediction is introduced.
We demonstrate a diode pumped Yb:LuVO4 laser that can be passively Q-switched by a Cr^(4+):YAG saturable absorber having an initial transmission as high as 99.3%.A maximum pulsed output power of 2.35 W is generat...We demonstrate a diode pumped Yb:LuVO4 laser that can be passively Q-switched by a Cr^(4+):YAG saturable absorber having an initial transmission as high as 99.3%.A maximum pulsed output power of 2.35 W is generated at a repetition rate of 285.7 kHz,approaching or very near the intrinsic upper limit imposed by the recovery time of the Cr^(4+):YAG saturable absorber,and the resulting pulse energy,duration and peak power are,respectively,8.2μJ,39.2ns and 0.209kW.展开更多
The year 1993 was the fifteenth of China’s reform and opening to the outside. Its economy sustained double digit growth for two years running. Last year, domestic GNP was RMB3,138 billion, a 13.4 percent increase com...The year 1993 was the fifteenth of China’s reform and opening to the outside. Its economy sustained double digit growth for two years running. Last year, domestic GNP was RMB3,138 billion, a 13.4 percent increase compared with the previous year’s 13.2 percent.展开更多
The use of finite element method leads to replacing the initial domain by an approaching domain. Under some appropriate assumptions, we prove that there exists a W1,+∞-diffeomorphism from the original domain to the a...The use of finite element method leads to replacing the initial domain by an approaching domain. Under some appropriate assumptions, we prove that there exists a W1,+∞-diffeomorphism from the original domain to the approaching domain.展开更多
China’s most important traditional festival,the Spring Festival,is approaching.Unlike religious festivals in Western countries,the Spring Festival is closely related to nature.By celebrating the arrival of spring,it ...China’s most important traditional festival,the Spring Festival,is approaching.Unlike religious festivals in Western countries,the Spring Festival is closely related to nature.By celebrating the arrival of spring,it embodies the idea of the renewal of all manifestations and the unity of nature and humans.At the same time,it is also a festival about family reunion,fully showing how much Chinese people cherish kinship,friendship,and familial harmony.This harmony between humans and nature,humans and society,and among humans themselves is the essence of the tradition of the Spring Festival,and is also a core cultural value pursued and cherished by the Chinese nation for thousands of years.Today,China’s internal affairs and diplomatic thoughts are permeated with the values of harmonious coexistence,and the Doctrine of the Mean is still the quintessential wisdom embraced by Chinese people who seek to achieve harmonious interpersonal relations with it.展开更多
There is no historical evidence of a connection between Chinese and African art, but today, artists from the two sides are making efforts to build just such a connection. On June 18, an art exhibition entitled Approac...There is no historical evidence of a connection between Chinese and African art, but today, artists from the two sides are making efforts to build just such a connection. On June 18, an art exhibition entitled Approaching Africa was held at Shenzhen University's art museum. The exhibition included more than 60 works by nine artists from Shenzhen's art institutes. The works were created by the artists during a tour of African countries including Benin, Kenya, Tanzania, Ethiopia and Zimbabwe.展开更多
Diana Vreeland,Editor in Chief of Vogue U.S.from 1962-71,once said,"Fashion is part of the daily air and it changes all the time,with all the events.You can even see the approaching of a revolution in clothes.You...Diana Vreeland,Editor in Chief of Vogue U.S.from 1962-71,once said,"Fashion is part of the daily air and it changes all the time,with all the events.You can even see the approaching of a revolution in clothes.You can see and feel everything in clothes."展开更多
1 It was a typical day and 18⁃year⁃old Lilly Baker was on her way to meet friends.She was approaching the railway intersection(交叉路口)when she noticed a frightening sight-an elderly woman confined to a wheelchair,tr...1 It was a typical day and 18⁃year⁃old Lilly Baker was on her way to meet friends.She was approaching the railway intersection(交叉路口)when she noticed a frightening sight-an elderly woman confined to a wheelchair,trapped on railroad tracks.Time was running out,and Lilly knew she had to act fast.展开更多
BACKGROUND Dislocation rates after hemiarthroplasty reportedly vary from 1%to 17%.This serious complication is associated with increased morbidity and mortality rates.Approaches to this surgery are still debated,with ...BACKGROUND Dislocation rates after hemiarthroplasty reportedly vary from 1%to 17%.This serious complication is associated with increased morbidity and mortality rates.Approaches to this surgery are still debated,with no consensus regarding the superiority of any single approach.AIM To compare early postoperative complications after implementing the direct anterior and posterior approaches(PL)for hip hemiarthroplasty after femoral neck fractures.METHODS This is a comparative,retrospective,single-center cohort study conducted at a university hospital.Between March 2008 and December 2018,273 patients(a total of 280 hips)underwent bipolar hemiarthroplasties(n=280)for displaced femoral neck fractures using either the PL(n=171)or the minimally invasive direct anterior approach(DAA)(n=109).The choice of approach was related to the surgeons’practices;the implant types were similar and unrelated to the approach.Dislocation rates and other complications were reviewed after a minimum followup of 6 mo.RESULTS Both treatment groups had similarly aged patients(mean age:82 years),sex ratios,patient body mass indexes,and patient comorbidities.Surgical data(surgery delay time,operative time,and blood loss volume)did not differ significantly between the groups.The 30 d mortality rate was higher in the PL group(9.9%)than in the DAA group(3.7%),but the difference was not statistically significant(P=0.052).Among the one-month survivors,a significantly higher rate of dislocation was observed in the PL group(14/154;9.1%)than in the DAA group(0/105;0%)(P=0.002).Of the 14 patients with dislocation,8 underwent revision surgery for recurrent instability(posterior group),and one of them had 2 additional procedures due to a deep infection.The rate of other complications(e.g.,perioperative and early postoperative periprosthetic fractures and infection-related complications)did not differ significantly between the groups.CONCLUSION These findings suggest that the DAA to bipolar hemiarthroplasty for patients with femoral neck fractures is associated with a lower dislocation rate(<1%)than the PL.展开更多
The expansion of a thick-walled hollow cylinder in soil is of non-self-similar nature that the stress/deformation paths are not the same for different soil material points.As a result,this problem cannot be solved by ...The expansion of a thick-walled hollow cylinder in soil is of non-self-similar nature that the stress/deformation paths are not the same for different soil material points.As a result,this problem cannot be solved by the common self-similar-based similarity techniques.This paper proposes a novel,exact solution for rigorous drained expansion analysis of a hollow cylinder of critical state soils.Considering stress-dependent elastic moduli of soils,new analytical stress and displacement solutions for the nonself-similar problem are developed taking the small strain assumption in the elastic zone.In the plastic zone,the cavity expansion response is formulated into a set of first-order partial differential equations(PDEs)with the combination use of Eulerian and Lagrangian descriptions,and a novel solution algorithm is developed to efficiently solve this complex boundary value problem.The solution is presented in a general form and thus can be useful for a wide range of soils.With the new solution,the non-self-similar nature induced by the finite outer boundary is clearly demonstrated and highlighted,which is found to be greatly different to the behaviour of cavity expansion in infinite soil mass.The present solution may serve as a benchmark for verifying the performance of advanced numerical techniques with critical state soil models and be used to capture the finite boundary effect for pressuremeter tests in small-sized calibration chambers.展开更多
A soil remediation method combining in situ reduction of Cr(VI) with approaching anodes electroki- netic (AAs-EK) remediation is proposed. EK experiments were conducted to compare the effect of approaching anodes ...A soil remediation method combining in situ reduction of Cr(VI) with approaching anodes electroki- netic (AAs-EK) remediation is proposed. EK experiments were conducted to compare the effect of approaching anodes (AAs) and fixed electrodes (FEs) with and without sodium bisulfite (NaHSO3) as a reducing agent. When NaHSO3 was added to the soil before EK treatment, 90.3% of the Cr(VI) was reduced to Cr(III). EK experiments showed that the adverse effect of contrasting migration of Cr(III) and Cr(VI) species, which limits the practical application of this technique, was eliminated in the presence of the reducing agent. Furthermore, Tessier fractionation analysis indicated that the reducing agent changed the distribution of the chemical forms of Cr. The AAs-EK method was shown to acidize the soil as the anode moved toward the cathode and this acid front pushed the "focusing" region toward the cathode. After remedia- tion, the pH of the soil was between 1.8 and 5.0 in AAs-EK experiments. The total Cr removal efficiency was 64.4% (except in the "focusing" region) when the reduction reaction was combined with AAs-EK method. We conclude that AAs-EK remediation in the presence of NaHSO3 is an appropriate method for Cr-contaminated soil.展开更多
BACKGROUND Total hip arthroplasty is as an effective intervention to relieve pain and improve hip function.Approaches of the hip have been exhaustively explored about pros and cons.The efficacy and the complications o...BACKGROUND Total hip arthroplasty is as an effective intervention to relieve pain and improve hip function.Approaches of the hip have been exhaustively explored about pros and cons.The efficacy and the complications of hip approaches remains inconclusive.This study conducted an umbrella review to systematically appraise previous meta-analysis(MAs)including conventional posterior approach(PA),and minimally invasive surgeries as the lateral approach(LA),direct anterior approach(DAA),2-incisions method,mini-lateral approach and the newest technique direct superior approach(DSA)or supercapsular percutaneouslyassisted total hip(SuperPath).AIM To compare the efficacy and complications of hip approaches that have been published in all MAs and randomized controlled trials(RCTs).METHODS MAs were identified from MEDLINE and Scopus from inception until 2023.RCTs were then updated from the latest MA to September 2023.This study included studies which compared hip approaches and reported at least one outcome such as Harris Hip Score(HHS),dislocation,intra-operative fracture,wound compliData were independently selected,extracted and assessed by two reviewers.Network MA and cluster rank and surface under the cumulative ranking curve(SUCRA)were estimated for treatment efficacy and safety.RESULTS Finally,twenty-eight MAs(40 RCTs),and 13 RCTs were retrieved.In total 47 RCTs were included for reanalysis.The results of corrected covered area showed high degree(13.80%).Among 47 RCTs,most of the studies were low risk of bias in part of random process and outcome reporting,while other domains were medium to high risk of bias.DAA significantly provided higher HHS at three months than PA[pooled unstandardized mean difference(USMD):3.49,95%confidence interval(CI):0.98,6.00 with SUCRA:85.9],followed by DSA/SuperPath(USMD:1.57,95%CI:-1.55,4.69 with SUCRA:57.6).All approaches had indifferent dislocation and intraoperative fracture rates.SUCRA comparing early functional outcome and composite complications(dislocation,intra-operative fracture,wound complication,and nerve injury)found DAA was the best approach followed by DSA/SuperPath.CONCLUSION DSA/SuperPath had better earlier functional outcome than PA,but still could not overcome the result of DAA.This technique might be the other preferred option with acceptable complications.展开更多
As a new technology used for the cleaning of chromium-contaminated soil, worldwide interest in ele- trokinetic (EK) remediation has grown considerably in recent times. However, owing to the fact that chromium exists...As a new technology used for the cleaning of chromium-contaminated soil, worldwide interest in ele- trokinetic (EK) remediation has grown considerably in recent times. However, owing to the fact that chromium exists as both cationic and anionic species in the soil, it is not an efficient method. This paper reports upon a study in which a process using approaching anodes (AAs) was used to enhance the removal efficiency of chromium by eletrokinetics. Two bench-scale experiments to remove chromium from contaminated soil were performed, one using a fixed anode (FA) and the other using AAs. In the AAs experiment, the anode moved toward the cathode by 7 cm every three days. After remediation, soil pH, total chromium, and fractionation of chromium in the soil were determined. The average removal efficiency of total chromium was 11.32% and 18.96% in the FA and AAs experiments, respectively. After remediation, acidic soil conditions throughout the soil were generated through the use of AAs, while 80% of the soil remained neutral or alkalic when using the FA approach. The acidic soil environment and high field intensity in the AAs experi- ment might have favored chromium desorption, dissolu- tion and dissociation from the soil, plus the mobility of chromium in the soil was also enhanced. The results demonstrate that AAs used in the process of EK remediation can enhance the efficiency of chromium removal from soil.展开更多
In this study, we focused on full-region cruise survey data, near-bottom continuous mooring observations and sea surface wind products from the western South Yellow Sea in winter; after ensuring the data reliability a...In this study, we focused on full-region cruise survey data, near-bottom continuous mooring observations and sea surface wind products from the western South Yellow Sea in winter; after ensuring the data reliability and accuracy, we processed and analyzed the data. Image resolution experiments were carried out to determine the lowest recognition resolutions for all image types, which represent the resolution characteristics of the data. The existence of a warm water tongue originating from the Yellow Sea Warm Current(YSWC) that approached waters offshore Qingdao was confirmed. For the first time, a high salinity water tongue, corresponding to the warm water tongue, was described and found to be more representative of the YSWC branch path. This warm tongue is a sign of the branch originating from the YSWC, which we defined as the Yellow Sea Warm Current Branch approaching waters offshore Qingdao(YSWC-QDB). The pattern of the warm and salty water tongues showed remarkable rear, branching middle, shrinking neck and expanding top regions. These patterns showed a temporal feature of the tongues, and were the result of multi-temporal branches in front of the YSWC main section as well as the YSWC-QDB crossing the southwestward path of the extension of the North Shandong Coastal Current flowing along the southeast coast of the Shandong Peninsula(NSCC-SESE). Analysis using mooring data at a sensitive and representative station also showed the existence of the YSWC-QDB. It is a probabilistic event that manifests as a northwestward flow that decreases gradually from the bottom to the surface in the early cold air transit stage and consistent in the whole water column profile in the later stage. It varies quasi-periodically with weather processes. It also transports some of the YSWC water stored in the entrance area of the Bohai and Yellow seas under winter wind conditions to the western South Yellow Sea as a compensatory current. This current, caused by northerly winds, especially northwest winds and obstruction of the NSCC-SESE, was present, and strong water reduction and compensation caused significant residual sea level oscillations. The compensatory current, if caused by strong northwest wind,began to appear when its direction was opposite to the wind direction. In addition, confirmation of the YSWC-QDB provides an oceanographic basis for the short cooling time and rapid warming in the Qingdao area in winter. This research provides a basis for further studies of the YSWC-QDB at high spatial and temporal resolutions using large sea surface datasets. For monsoon basin dynamics, this study can also be extended to the whole Bohai and Yellow seas and closed or semi-closed basins on the continental margin.展开更多
Noncoherent underwater acoustic communication channel in adverse conditions is modeled as a phase-random Rayleigh fading channel,and its capacity curve is derived.To approach the channel capacity curve,the concatenate...Noncoherent underwater acoustic communication channel in adverse conditions is modeled as a phase-random Rayleigh fading channel,and its capacity curve is derived.To approach the channel capacity curve,the concatenated code of the nonbinary LDPC code and the constant weight code is proposed for noncoherent communication which can late be iteratively decoded in the probability domain.Without information of channel amplitude or phase in the receiver,statistic parameters of the respective signal and noise bins were estimated based on the moment estimation method,the posterior probabilities of the constant weight code words were further calculated,and the nonbinary LDPC code was decoded with the nonbinary factor graph algorithm.It is verified by simulations that by utilizing the proposed concatenated code and its processing algorithm,gap to channel capacity curve is reduced by 3 dB when compared to the existing method.Underwater communication experiments were carried out in both deep ocean(vertical communication,5 km)and shallow lake(horizontal communication,near 3 km,delay spread larger than 50 ms),in which the signal frequency band was 6 kHz to10 kHz,and the data transmission rate Was 357 bps.The proposed scheme can work properly in both experiments with a signal-to-noise ratio threshold of 2 dB.The performance of the proposed algorithm Was well verified by the experiments.展开更多
文摘Desertification creeps across the landscape like a silent thief,stealing life and leaving behind a barren wasteland.This year's World Environment Day theme,‘Land Restoration,desertification and drought resilience’,is a stark reminder of the pressing need to heal the wounds we've inflicted on our planet.
文摘By establishing the concepts of fuzzy approaching set and fuzzy approaching functional mapping and making research on them, a new method for time series prediction is introduced.
基金Supported by the National Natural Science Foundation of China under Grant No 11574170
文摘We demonstrate a diode pumped Yb:LuVO4 laser that can be passively Q-switched by a Cr^(4+):YAG saturable absorber having an initial transmission as high as 99.3%.A maximum pulsed output power of 2.35 W is generated at a repetition rate of 285.7 kHz,approaching or very near the intrinsic upper limit imposed by the recovery time of the Cr^(4+):YAG saturable absorber,and the resulting pulse energy,duration and peak power are,respectively,8.2μJ,39.2ns and 0.209kW.
文摘The year 1993 was the fifteenth of China’s reform and opening to the outside. Its economy sustained double digit growth for two years running. Last year, domestic GNP was RMB3,138 billion, a 13.4 percent increase compared with the previous year’s 13.2 percent.
基金Partially supported by Professor Xu Yuesheng and his program "One hundred distinguished Young Scientists" Partially supported by "Programme Sino-Francais de Recherches Advancees(PRA).
文摘The use of finite element method leads to replacing the initial domain by an approaching domain. Under some appropriate assumptions, we prove that there exists a W1,+∞-diffeomorphism from the original domain to the approaching domain.
文摘China’s most important traditional festival,the Spring Festival,is approaching.Unlike religious festivals in Western countries,the Spring Festival is closely related to nature.By celebrating the arrival of spring,it embodies the idea of the renewal of all manifestations and the unity of nature and humans.At the same time,it is also a festival about family reunion,fully showing how much Chinese people cherish kinship,friendship,and familial harmony.This harmony between humans and nature,humans and society,and among humans themselves is the essence of the tradition of the Spring Festival,and is also a core cultural value pursued and cherished by the Chinese nation for thousands of years.Today,China’s internal affairs and diplomatic thoughts are permeated with the values of harmonious coexistence,and the Doctrine of the Mean is still the quintessential wisdom embraced by Chinese people who seek to achieve harmonious interpersonal relations with it.
文摘There is no historical evidence of a connection between Chinese and African art, but today, artists from the two sides are making efforts to build just such a connection. On June 18, an art exhibition entitled Approaching Africa was held at Shenzhen University's art museum. The exhibition included more than 60 works by nine artists from Shenzhen's art institutes. The works were created by the artists during a tour of African countries including Benin, Kenya, Tanzania, Ethiopia and Zimbabwe.
文摘Diana Vreeland,Editor in Chief of Vogue U.S.from 1962-71,once said,"Fashion is part of the daily air and it changes all the time,with all the events.You can even see the approaching of a revolution in clothes.You can see and feel everything in clothes."
文摘1 It was a typical day and 18⁃year⁃old Lilly Baker was on her way to meet friends.She was approaching the railway intersection(交叉路口)when she noticed a frightening sight-an elderly woman confined to a wheelchair,trapped on railroad tracks.Time was running out,and Lilly knew she had to act fast.
基金This study was reviewed and approved by the Ethics Committee of the HUB-Hospital Erasme.
文摘BACKGROUND Dislocation rates after hemiarthroplasty reportedly vary from 1%to 17%.This serious complication is associated with increased morbidity and mortality rates.Approaches to this surgery are still debated,with no consensus regarding the superiority of any single approach.AIM To compare early postoperative complications after implementing the direct anterior and posterior approaches(PL)for hip hemiarthroplasty after femoral neck fractures.METHODS This is a comparative,retrospective,single-center cohort study conducted at a university hospital.Between March 2008 and December 2018,273 patients(a total of 280 hips)underwent bipolar hemiarthroplasties(n=280)for displaced femoral neck fractures using either the PL(n=171)or the minimally invasive direct anterior approach(DAA)(n=109).The choice of approach was related to the surgeons’practices;the implant types were similar and unrelated to the approach.Dislocation rates and other complications were reviewed after a minimum followup of 6 mo.RESULTS Both treatment groups had similarly aged patients(mean age:82 years),sex ratios,patient body mass indexes,and patient comorbidities.Surgical data(surgery delay time,operative time,and blood loss volume)did not differ significantly between the groups.The 30 d mortality rate was higher in the PL group(9.9%)than in the DAA group(3.7%),but the difference was not statistically significant(P=0.052).Among the one-month survivors,a significantly higher rate of dislocation was observed in the PL group(14/154;9.1%)than in the DAA group(0/105;0%)(P=0.002).Of the 14 patients with dislocation,8 underwent revision surgery for recurrent instability(posterior group),and one of them had 2 additional procedures due to a deep infection.The rate of other complications(e.g.,perioperative and early postoperative periprosthetic fractures and infection-related complications)did not differ significantly between the groups.CONCLUSION These findings suggest that the DAA to bipolar hemiarthroplasty for patients with femoral neck fractures is associated with a lower dislocation rate(<1%)than the PL.
基金funding support from the National Key Research and Development Program of China(Grant No.2023YFB2604004)the National Natural Science Foundation of China(Grant No.52108374)the“Taishan”Scholar Program of Shandong Province,China(Grant No.tsqn201909016)。
文摘The expansion of a thick-walled hollow cylinder in soil is of non-self-similar nature that the stress/deformation paths are not the same for different soil material points.As a result,this problem cannot be solved by the common self-similar-based similarity techniques.This paper proposes a novel,exact solution for rigorous drained expansion analysis of a hollow cylinder of critical state soils.Considering stress-dependent elastic moduli of soils,new analytical stress and displacement solutions for the nonself-similar problem are developed taking the small strain assumption in the elastic zone.In the plastic zone,the cavity expansion response is formulated into a set of first-order partial differential equations(PDEs)with the combination use of Eulerian and Lagrangian descriptions,and a novel solution algorithm is developed to efficiently solve this complex boundary value problem.The solution is presented in a general form and thus can be useful for a wide range of soils.With the new solution,the non-self-similar nature induced by the finite outer boundary is clearly demonstrated and highlighted,which is found to be greatly different to the behaviour of cavity expansion in infinite soil mass.The present solution may serve as a benchmark for verifying the performance of advanced numerical techniques with critical state soil models and be used to capture the finite boundary effect for pressuremeter tests in small-sized calibration chambers.
文摘A soil remediation method combining in situ reduction of Cr(VI) with approaching anodes electroki- netic (AAs-EK) remediation is proposed. EK experiments were conducted to compare the effect of approaching anodes (AAs) and fixed electrodes (FEs) with and without sodium bisulfite (NaHSO3) as a reducing agent. When NaHSO3 was added to the soil before EK treatment, 90.3% of the Cr(VI) was reduced to Cr(III). EK experiments showed that the adverse effect of contrasting migration of Cr(III) and Cr(VI) species, which limits the practical application of this technique, was eliminated in the presence of the reducing agent. Furthermore, Tessier fractionation analysis indicated that the reducing agent changed the distribution of the chemical forms of Cr. The AAs-EK method was shown to acidize the soil as the anode moved toward the cathode and this acid front pushed the "focusing" region toward the cathode. After remedia- tion, the pH of the soil was between 1.8 and 5.0 in AAs-EK experiments. The total Cr removal efficiency was 64.4% (except in the "focusing" region) when the reduction reaction was combined with AAs-EK method. We conclude that AAs-EK remediation in the presence of NaHSO3 is an appropriate method for Cr-contaminated soil.
文摘BACKGROUND Total hip arthroplasty is as an effective intervention to relieve pain and improve hip function.Approaches of the hip have been exhaustively explored about pros and cons.The efficacy and the complications of hip approaches remains inconclusive.This study conducted an umbrella review to systematically appraise previous meta-analysis(MAs)including conventional posterior approach(PA),and minimally invasive surgeries as the lateral approach(LA),direct anterior approach(DAA),2-incisions method,mini-lateral approach and the newest technique direct superior approach(DSA)or supercapsular percutaneouslyassisted total hip(SuperPath).AIM To compare the efficacy and complications of hip approaches that have been published in all MAs and randomized controlled trials(RCTs).METHODS MAs were identified from MEDLINE and Scopus from inception until 2023.RCTs were then updated from the latest MA to September 2023.This study included studies which compared hip approaches and reported at least one outcome such as Harris Hip Score(HHS),dislocation,intra-operative fracture,wound compliData were independently selected,extracted and assessed by two reviewers.Network MA and cluster rank and surface under the cumulative ranking curve(SUCRA)were estimated for treatment efficacy and safety.RESULTS Finally,twenty-eight MAs(40 RCTs),and 13 RCTs were retrieved.In total 47 RCTs were included for reanalysis.The results of corrected covered area showed high degree(13.80%).Among 47 RCTs,most of the studies were low risk of bias in part of random process and outcome reporting,while other domains were medium to high risk of bias.DAA significantly provided higher HHS at three months than PA[pooled unstandardized mean difference(USMD):3.49,95%confidence interval(CI):0.98,6.00 with SUCRA:85.9],followed by DSA/SuperPath(USMD:1.57,95%CI:-1.55,4.69 with SUCRA:57.6).All approaches had indifferent dislocation and intraoperative fracture rates.SUCRA comparing early functional outcome and composite complications(dislocation,intra-operative fracture,wound complication,and nerve injury)found DAA was the best approach followed by DSA/SuperPath.CONCLUSION DSA/SuperPath had better earlier functional outcome than PA,but still could not overcome the result of DAA.This technique might be the other preferred option with acceptable complications.
文摘As a new technology used for the cleaning of chromium-contaminated soil, worldwide interest in ele- trokinetic (EK) remediation has grown considerably in recent times. However, owing to the fact that chromium exists as both cationic and anionic species in the soil, it is not an efficient method. This paper reports upon a study in which a process using approaching anodes (AAs) was used to enhance the removal efficiency of chromium by eletrokinetics. Two bench-scale experiments to remove chromium from contaminated soil were performed, one using a fixed anode (FA) and the other using AAs. In the AAs experiment, the anode moved toward the cathode by 7 cm every three days. After remediation, soil pH, total chromium, and fractionation of chromium in the soil were determined. The average removal efficiency of total chromium was 11.32% and 18.96% in the FA and AAs experiments, respectively. After remediation, acidic soil conditions throughout the soil were generated through the use of AAs, while 80% of the soil remained neutral or alkalic when using the FA approach. The acidic soil environment and high field intensity in the AAs experi- ment might have favored chromium desorption, dissolu- tion and dissociation from the soil, plus the mobility of chromium in the soil was also enhanced. The results demonstrate that AAs used in the process of EK remediation can enhance the efficiency of chromium removal from soil.
基金supported by the National Natural Science Foundation of China (Grant Nos. 41376038, 40406009 & 41806123)the National Science and Technology Major Project of the Ministry of Science and Technology of China (Grant No. 2016ZX05057015)+1 种基金the NSFC-Shandong Joint Fund for Marine Science Research Centers of China (Grant No. U1606405)the National Program on Global Change and Air-Sea Interaction of China (Grant Nos. GASI-IPOVAI-01-05 & GASI02-IND-STSsum)
文摘In this study, we focused on full-region cruise survey data, near-bottom continuous mooring observations and sea surface wind products from the western South Yellow Sea in winter; after ensuring the data reliability and accuracy, we processed and analyzed the data. Image resolution experiments were carried out to determine the lowest recognition resolutions for all image types, which represent the resolution characteristics of the data. The existence of a warm water tongue originating from the Yellow Sea Warm Current(YSWC) that approached waters offshore Qingdao was confirmed. For the first time, a high salinity water tongue, corresponding to the warm water tongue, was described and found to be more representative of the YSWC branch path. This warm tongue is a sign of the branch originating from the YSWC, which we defined as the Yellow Sea Warm Current Branch approaching waters offshore Qingdao(YSWC-QDB). The pattern of the warm and salty water tongues showed remarkable rear, branching middle, shrinking neck and expanding top regions. These patterns showed a temporal feature of the tongues, and were the result of multi-temporal branches in front of the YSWC main section as well as the YSWC-QDB crossing the southwestward path of the extension of the North Shandong Coastal Current flowing along the southeast coast of the Shandong Peninsula(NSCC-SESE). Analysis using mooring data at a sensitive and representative station also showed the existence of the YSWC-QDB. It is a probabilistic event that manifests as a northwestward flow that decreases gradually from the bottom to the surface in the early cold air transit stage and consistent in the whole water column profile in the later stage. It varies quasi-periodically with weather processes. It also transports some of the YSWC water stored in the entrance area of the Bohai and Yellow seas under winter wind conditions to the western South Yellow Sea as a compensatory current. This current, caused by northerly winds, especially northwest winds and obstruction of the NSCC-SESE, was present, and strong water reduction and compensation caused significant residual sea level oscillations. The compensatory current, if caused by strong northwest wind,began to appear when its direction was opposite to the wind direction. In addition, confirmation of the YSWC-QDB provides an oceanographic basis for the short cooling time and rapid warming in the Qingdao area in winter. This research provides a basis for further studies of the YSWC-QDB at high spatial and temporal resolutions using large sea surface datasets. For monsoon basin dynamics, this study can also be extended to the whole Bohai and Yellow seas and closed or semi-closed basins on the continental margin.
基金supported by the Chinese National 863 Projects(2002AA401004,2009AA093301,2009AA093601)
文摘Noncoherent underwater acoustic communication channel in adverse conditions is modeled as a phase-random Rayleigh fading channel,and its capacity curve is derived.To approach the channel capacity curve,the concatenated code of the nonbinary LDPC code and the constant weight code is proposed for noncoherent communication which can late be iteratively decoded in the probability domain.Without information of channel amplitude or phase in the receiver,statistic parameters of the respective signal and noise bins were estimated based on the moment estimation method,the posterior probabilities of the constant weight code words were further calculated,and the nonbinary LDPC code was decoded with the nonbinary factor graph algorithm.It is verified by simulations that by utilizing the proposed concatenated code and its processing algorithm,gap to channel capacity curve is reduced by 3 dB when compared to the existing method.Underwater communication experiments were carried out in both deep ocean(vertical communication,5 km)and shallow lake(horizontal communication,near 3 km,delay spread larger than 50 ms),in which the signal frequency band was 6 kHz to10 kHz,and the data transmission rate Was 357 bps.The proposed scheme can work properly in both experiments with a signal-to-noise ratio threshold of 2 dB.The performance of the proposed algorithm Was well verified by the experiments.