The pig-on-litter system is characterized by reduced environmental pollution and high-quality pork. It has won the support of the government and the acceptance of market. It is urgent to develop the supporting facilit...The pig-on-litter system is characterized by reduced environmental pollution and high-quality pork. It has won the support of the government and the acceptance of market. It is urgent to develop the supporting facilities and products to promote the comprehensive promotion of this technology. Based on the climatic and hydro- logical conditions in Jiangsu Province, we designed the removable deep-litter breed- ing shed. Its construction costs were lower than that of ordinary water-flushed pig- gery. In addition, this breeding system would not consolidate the land. The indoor ventilation and heat-conservation performances also met the requirements by pig-on- litter system. The removable shed can be promoted as an important supporting technology for the deep-litter breeding model in the eastern China.展开更多
A new simplified removable ground test-bed was designed for testing a certainturbofan engine. The facilities are 5.5 m long, 1.5 m wide, 2.2 m high and not more than 4. 5 t ofits empty weight. There are four rubber wh...A new simplified removable ground test-bed was designed for testing a certainturbofan engine. The facilities are 5.5 m long, 1.5 m wide, 2.2 m high and not more than 4. 5 t ofits empty weight. There are four rubber wheels that could be towed. There is an independentelectrical measurement and control system to test the rotational speed of rotors, the gas pressureof the compressor, the exhaust gas temperature, etc. Cooperated with the oil truck and the electricpower supply truck, the turbofan engine could be preserved on the ground and started to the idlingregime. While running, the parameter of the engine could be recorded, disposed and displayed. Inaddition, the facilities were successfully applied to the plateau experiment in order to researchhow the atmosphere pressure affects the start of engines. Some data are given in the paper.展开更多
Anti-ram bollard systems, which are installed around buildings and infrastructure, can prevent unauthorized vehicles from entering, maintain distance from vehicle-borne improvised explosive devices （VBIED） and reduc...Anti-ram bollard systems, which are installed around buildings and infrastructure, can prevent unauthorized vehicles from entering, maintain distance from vehicle-borne improvised explosive devices （VBIED） and reduce the corresponding damage. Compared with a fixed bollard system, a removable bollard system provides more flexibility as it can be removed when needed. This paper first proposes a new type of K4-rated removable anti-ram bollard system. To simulate the collision of a vehicle hitting the bollard system, a finite element model was then built and verified through comparison of numerical simulation results and existing experimental results. Based on the orthogonal design method, the factors influencing the safety and economy of this proposed system were examined and sorted according to their importance. An optimal design scheme was then produced. Finally, to validate the effectiveness of the proposed design scheme, four dynamic impact tests, including two front impact tests and two side impact tests, have been conducted according to BSI Specifications. The residual rotation angles of the specimen are smaller than 30~ and satisfy the requirements of the BSI Specification.展开更多
In this paper we consider a nondivergent elliptic equation of second order whose leading coefficients are from some weight space. The sufficient condition of removability of a compact with respect to this equation in ...In this paper we consider a nondivergent elliptic equation of second order whose leading coefficients are from some weight space. The sufficient condition of removability of a compact with respect to this equation in the weight space of Holder functions was found.展开更多
Removable partial dentures (RPDs) (conventional and implant-supported) treatment is considered a viable option to replace missing teeth as inexpensively as possible, but it has limitations. Objectives: This study repo...Removable partial dentures (RPDs) (conventional and implant-supported) treatment is considered a viable option to replace missing teeth as inexpensively as possible, but it has limitations. Objectives: This study reports the effect of gender and location (maxilla vs. mandible) on the clinical performance of removable partial dentures (RPDs). Materials and Methods: A total of 100 Patients who had RPDs delivered between 1990-1995 were evaluated. A 4-point scoring system was used to assess seventeen criteria. These criteria include acceptance, stability, support, retention, adaptation, occlusion, integrity, and design of the pros-theses, rest and rest seat preparation, occlusal wear, esthetics, phonetics, tissue condition, mobility of abutments, gingival and plaque indices. The data were analyzed using Kruskal-Wallis and Mann-Whitney U non-parametric statistical tests. Results: The results showed that acceptance of RPDs was rated the lowest. Other reasons for failure were poor retention, lack of integrity of the prostheses and inadequate adaptation. Retention and design of major connectors attributed to Mandibular RPD failure. Success rate of 75% was observed in male compared with 67.2% for female. Maxillary RPDs showed a higher success rate (78%) compared with the mandibular (70.1%). No significant statistical difference in Alpha scores between female and male patients and between maxillary and mandibular RPDs (p < 0.05). Conclusions: The clinical performance of RPDs showed a higher success rate in male patients compared to female patients and the maxillary RPDs showed a higher success rate compared to mandibular.展开更多
The aim of this study was to evaluate whether partial removable denture use indeed leads to improved oral health related quality of life and masticatory function. Materials and Methods: Partially edentulous patients p...The aim of this study was to evaluate whether partial removable denture use indeed leads to improved oral health related quality of life and masticatory function. Materials and Methods: Partially edentulous patients presenting for removable denture treatment at the Prosthodontics Service in the Hospital Affiliated to Kinshasa University (Democratic Republic of Congo) were assessed for enrolment in this study. After applying exclusion criteria, 378 patients were included in the study, and randomly assigned into 2 groups. Oral health related quality of life (OHIP-23) and mastication time (MaT), number of chewing cycles (MaC), mastication frequency (MaF), and the sizes of the peanut fragments (FraS) were compared in both groups. Statistical significance was set at p < 0.05. Results: The average MaC, MaT, MaF, and FraS were 119 (± SD 53.70), 86.75 (±SD 35.35), 1.38 (±SD 0.25), and 3.3 (±SD 3.25) for the denture group and 77.9 (±SD 23.9), 60.2 (±SD 17.91), 1.29 (±SD 0.15), and 1.5 (±SD 0.7) for the non-denture group, respectively. Conclusion: The overall oral health related quality of life was best in the non-denture than denture.展开更多
Objective: The goal of the removable partial denture is to restore impaired esthetics and masticatory function by replacing missing teeth. The aim of this study was to establish a possible correla-tion between removab...Objective: The goal of the removable partial denture is to restore impaired esthetics and masticatory function by replacing missing teeth. The aim of this study was to establish a possible correla-tion between removable partial denture in acrylic resin use after 5 years and dental diseases. Materials and Methods: Partially edentulous patients presenting for removable denture treatment at the Prosthodontics service of the Affiliated Hospital of Kinshasa University, Democratic Republic of Congo were assessed in this study. Patients were randomly assigned into 2 groups: Denture and non-denture group. Caries and periodontal diseases were compared between both groups. Statistical significance was set at p < 0.05. Results: The average age in the denture and non-denture-group was 53.15 (±SD 22.05) and 31.59 (±SD 11.98) years. Out of 160 teeth were decayed, both 110 teeth (68.75%) in the denture-group and 50 teeth (31.25%) in the non-denture group. The DMFT index calculated at start time of the study was 0.2 for both groups, after five years was 7.1 for the denture-group and 2.6 for the non-denture-group. The plaque index in the denture-group had an index of 1 and that of non-denture-group was 0.5. Conclusion: The relationship has been found between patients’ wearers a RPD and dental diseases.展开更多
A novel kind of fully bio-based PSAs we re obtained through the curing reaction between two components derived from the plant oils:carboxyl-terminated polyricinoleate(PRA) fro m the castor oil and epoxidized soybean o...A novel kind of fully bio-based PSAs we re obtained through the curing reaction between two components derived from the plant oils:carboxyl-terminated polyricinoleate(PRA) fro m the castor oil and epoxidized soybean oil(ESO).The get content,glass transition temperature(Tg),rheological behavior,tensile strength,creep resistance and 180° peel strength of the PSAs were feasibly tailored by adjusting the component ratio of ESO to PRA.At low cross-linking level,the PSAs behaved like a viscous liquid and did not possess enough cohesiveness to sustain the mechanical stress during peeling,The PSAs cross-linked at or near the optimal stoichiometric conditions displayed an adhesive(interfacial) failure between the substrate and the adhesive layer,which were associated with the lowest adhesion levels.The PSAs with the dosage amount of ESO ranging from 10.20 wt% were tacky and flexible,which exhibited 1800 peel strength ranging from 0.4~2.3 N/cm;and could be easily removed without any residues on the adherend.The process for the preparation of the fully bio-based PSAs was environmentally friendly without using any orga nic solve nt or other toxic chemical,herein showing the great potential as sustainable materials.展开更多
Comprehensive Summary The strategy of removable glycosylation modification was used to overcome the low-efficiency problem encountered in the chemical synthesis of the mirror-image D-version of the immunoglobulin(Ig)-...Comprehensive Summary The strategy of removable glycosylation modification was used to overcome the low-efficiency problem encountered in the chemical synthesis of the mirror-image D-version of the immunoglobulin(Ig)-like domain of tropomyosin receptor kinase A(DlgCTrkA),a protein molecule needed for mirror-image screening of D-peptide ligands targeting this cell membrane receptor.It was found that O-linked-β-N-acetyl-D-glucosamine(O-GlcNAc)modification at^(D)Ser^(312),or^(D)Ser^(320)can significantly improve the efficiency of DlgCTrkA synthesis and folding,while O-GlcNAc modification at^(D)Ser^(330)showed barely any improvement.This study provides a new example demonstrating the power of the removable glycosylation modification strategy in the chemical synthesis and folding of difficult-to-obtain proteins.It also presents evidence that removable glycosylation modification at different sites would significantly affect the efficiency of protein folding promoted by this strategy.展开更多
Carvalho, Lucchesi and Murty proved that any 1-extendable graph G different from K2 and C2n has at least A（G） edge-disjoint removable ears, and any brick G distinct from K4 and C6 has at least A（G） - 2 removable e...Carvalho, Lucchesi and Murty proved that any 1-extendable graph G different from K2 and C2n has at least A（G） edge-disjoint removable ears, and any brick G distinct from K4 and C6 has at least A（G） - 2 removable edges, where A（G） denotes the maximum degree of G. In this paper, we improve the lower bounds for numbers of removable ears and removable edges of 1-extendable graphs. It is proved that any 1-extendable graph G different from K2 and C2n has at least x′（G） edge-disjoint removable ears, and any brick G distinct from Ka and Ce has at least x′（G） - 2 removable edges, where x′（G） denotes the edge-chromatic number of G. Key words 1-extendable graphs, removable ear, removable edge.展开更多
Rational design and simple synthesis of one-dimensional nanofibers with high specific surface areas and hierarchically porous structures are still challenging. In the present work, a novel strategy utilizing a thermal...Rational design and simple synthesis of one-dimensional nanofibers with high specific surface areas and hierarchically porous structures are still challenging. In the present work, a novel strategy utilizing a thermally removable template was developed to synthesize hierarchically porous N-doped carbon nanofibers （HP-NCNFs） through the use of simple electrospinning technology coupled with subsequent pyrolysis. During the pyrolysis process, ZnO nanoparticles can be formed in situ and act as a thermally removable template due to their decomposition and sublimation under high-temperature conditions. The resulting HP-NCNFs have lengths of up to hundreds of micrometers with an average diameter of 300 nm and possess a hierarchically porous structure throughout. Such unique structures endow HP-NCNFs with a high specific surface area of up to 829.5 m2-g 1, which is 2.6 times higher than that （323.2 m2.g 1） of conventional N-doped carbon nanofibers （NCNFs）. Compared with conventional NCNFs, the HP-NCNF catalyst exhibited greatly enhanced catalytic performance and improved kinetics for the oxygen reduction reaction （ORR） in alkaline media. Moreover, the HP-NCNFs even showed better stability and stronger methanol crossover effect tolerance than the commerdal Pt-C catalyst. The optimized ORR performance can be attributed to the synergetic contribution of continuous and three-dimensional （3D） cross-linked structures, graphene-like structure on the edge of the HP- NCNFs, high specific surface area, and a hierarchically porous structure.展开更多
A Caccioppoli type estimate is established for a class of second order PDEs of divergence type, and its removable singularities of Hausdorff dimension greater than zero is obtained.
The remarkable ability of titanium alloys to preserve their superior physical and chemical characteristics when subjected to extreme conditions significantly enhances their importance in the aerospace,military,and med...The remarkable ability of titanium alloys to preserve their superior physical and chemical characteristics when subjected to extreme conditions significantly enhances their importance in the aerospace,military,and medical sectors.However,conventional machining of titanium alloys leads to elevated tool wear,development of surface defects,and reduced machining efficiency due to their low heat conductivity,and chemical affinity.These issues can be somewhat counteracted by integrating ultrasonic vibration in the conventional machining of titanium alloys and also enhance sustainability.This review article offers a holistic evaluation of the influence of ultrasonic vibration-assisted milling and turning on cutting forces,temperature,tool wear,and surface integrity,encompassing surface morphology,surface roughness,surface residual stress,surface hardness,and surface tribological properties during titanium alloys machining.Furthermore,it investigates the sustainability aspect that has not been previously examined.Studies on the performance of ultrasonic-assisted cutting revealed several advantages,including decreased cutting forces and cutting temperature,improved tool life,and a better-machined surface during machining.Consequently,the sustainability factor is improved due to minimized energy consumption and residual waste.In conclusion,the key challenges and future prospects in the ultrasonic-assisted cutting of titanium alloys are also discussed.This review article provides beneficial knowledge for manufactur-ers and researchers regarding ultrasonic vibration-assisted cutting of titanium alloy and will play an important role in achieving sustainability in the industry.展开更多
This paper investigates the propagation of computer viruses and establishes a novel propagation model. In contrast to the existing models,this model can directly indicate the impact of removable media and external com...This paper investigates the propagation of computer viruses and establishes a novel propagation model. In contrast to the existing models,this model can directly indicate the impact of removable media and external computers on the propagation of computer virus. The stability results of equilibrium point are derived by Hurwitz criterion and Bendixson Dulac criterion. The effectiveness of the proposed results is shown by numerical simulation. In order to show the superiority of the proposed model,some comparisons with the existing models are presented. The acceptable threshold and the reasonable strategies for suppressing the propagation of computer virus are also suggested,respectively.展开更多
Nitrogen removal from domestic sewage is usually limited by insufficient carbon source and electron donor.An economical solid carbon source was developed by composition of polyvinyl alcohol,sodium alginate,and corncob...Nitrogen removal from domestic sewage is usually limited by insufficient carbon source and electron donor.An economical solid carbon source was developed by composition of polyvinyl alcohol,sodium alginate,and corncob,which was utilized as external carbon source in the anaerobic anoxic oxic(AAO)-biofilter for the treatment of low carbon-to-nitrogen ratio domestic sewage,and the nitrogen removal was remarkably improved from 63.2%to 96.5%.Furthermore,the effluent chemical oxygen demand maintained at 35 mg/L or even lower,and the total nitrogenwas reduced to less than 2mg/L.Metagenomic analysis demonstrated that the microbial communities responsible for potential denitrification and organic matter degradation in both AAO and the biofilter reactors were mainly composed of Proteobacteria and Bacteroides,respectively.The solid carbon source addition resulted in relatively high abundance of functional enzymes responsible for NO_(3)^(−)-N to NO_(2)^(−)-N con-version in both AAO and the biofilter reactors,thus enabled stable reaction.The carbon source addition during glycolysis primarily led to the increase of genes associated with the metabolic conversion of fructose 1.6P2 to glycerol-3P The reactor maintained high abun-dance of genes related to the tricarboxylic acid cycle,and then guaranteed efficient carbon metabolism.The results indicate that the composite carbon source is feasible for denitri-fication enhancement of AAO-biofilter,which contribute to the theoretical foundation for practical nitrogen removal application.展开更多
Current research primarily focuses on emerging organic pollutants,with limited attention to emerging inorganic pollutants (EIPs).However,due to advances in detection technology and the escalating environmental and hea...Current research primarily focuses on emerging organic pollutants,with limited attention to emerging inorganic pollutants (EIPs).However,due to advances in detection technology and the escalating environmental and health challenges posed by pollution,there is a growing interest in treating waters contaminated with EIPs.This paper explores biochar characteristics and modification methods,encompassing physical,chemical,and biological approaches for adsorbing EIPs.It offers a comprehensive review of research advancements in employing biochar for EIPs remediation in water,outlines the adsorption mechanisms of EIPs by biochar,and presents an environmental and economic analysis.It can be concluded that using biochar for the adsorption of EIPs in wastewater exhibits promising potential.Nonetheless,it is noteworthy that certain EIPs like Au(III),Rh(III),Ir(III),Ru(III),Os(III),Sc(III),and Y(III),have not been extensively investigated regarding their adsorption onto biochar.This comprehensive review will catalyze further inquiry into the biochar-based adsorption of EIPs,addressing current research deficiencies and advancing the practical implementation of biochar as a potent substrate for EIP removal from wastewater streams.展开更多
Owing to the complexity of multicomponent gases,developing multifunctional catalysts for synergistic removal of benzene and toluene remains challenging.The spinel MMn_(2)O_(4)(M=Co,Ni,or Cu)catalysts were successfully...Owing to the complexity of multicomponent gases,developing multifunctional catalysts for synergistic removal of benzene and toluene remains challenging.The spinel MMn_(2)O_(4)(M=Co,Ni,or Cu)catalysts were successfully synthesized via the sol–gel method and tested for their catalytic performance for simultaneous degradation of benzene and toluene.The CuMn_(2)O_(4)sample exhibited the best catalytic performance,the conversion of benzene reached 100%at 350℃,and toluene conversion reached 100%at 250℃.XRD,N_(2)adsorption-desorption,HRTEM-EDS,ED-XRF,Raman spectroscopy,H_(2)-TPR,NH_(3)-TPD,O_(2)-TPD and XPS were used to characterize the physical and chemical properties of MMn_(2)O_(4)catalysts.The excellent redox properties,high concentration of surface Mn4+,and adsorption of oxygen species over the CuMn_(2)O_(4)sample facilitated the simultaneous and efficient removal of benzene and toluene.Additionally,in situ DRIFTS illustrated the intermediate species and reaction mechanism for the synergetic catalytic oxidation of benzene and toluene.Notably,as an effective catalytic material,spinel oxide exhibited excellent synergistic degradation performance for benzene and toluene,providing some insight for the development of efficient multicomponent VOC catalysts.展开更多
The rapidly growing demand for lithium iron phosphate(LiFePO_(4))as the cathode material of lithium-ion batteries(LIBs)has aggravated the scarcity of phosphorus(P)reserves on Earth.This study introduces an environment...The rapidly growing demand for lithium iron phosphate(LiFePO_(4))as the cathode material of lithium-ion batteries(LIBs)has aggravated the scarcity of phosphorus(P)reserves on Earth.This study introduces an environmentally friendly and economical method of P recovery from municipal wastewater,providing the P source for LiFePO_(4) cathodes.The novel approach utilizes the sludge of Fe-coagulant-based chemical P removal(CPR)in wastewater treatment.After a sintering treatment with acid washing,the CPR sludge,enriched with P and Fe,transforms into purified P-Fe oxides(Fe2.1P1.0O5.6).These oxides can substitute up to 35%of the FePO_(4) reagent as precursor,producing a carbon-coated LiFePO_(4)(LiFePO_(4)/C)cathode with a specific discharge capacity of 114.9 mA·h·g^(-1)at current density of 17 mA·g^(-1)),and cycle stability of 99.2%after 100 cycles.The enhanced cycle performance of the as-prepared LiFePO_(4)/C cathode may be attributed to the incorporations of impurities(such as Ca^(2+)and Na^(+))from sludge,with improved stability of crystal structure.Unlike conventional P-fertilizers,this P recovery technology converts 100%of P in CPR sludge into the production of value-added LiFePO_(4)/C cathodes.The recovered P from municipal wastewater can meet up to 35%of the P demand in the Chinese LIBs industry,offering a cost-effective solution for addressing the pressing challenges of P scarcity.展开更多
Wigner-Ville distribution(WVD)is widely used in the field of signal processing due to its excellent time-frequency(TF)concentration.However,WVD is severely limited by the cross-term when working with multicomponent si...Wigner-Ville distribution(WVD)is widely used in the field of signal processing due to its excellent time-frequency(TF)concentration.However,WVD is severely limited by the cross-term when working with multicomponent signals.In this paper,we analyze the property differences between auto-term and cross-term in the one-dimensional sequence and the two-dimensional plane and approximate entropy and Rényi entropy are employed to describe them,respectively.Based on this information,we propose a new method to achieve adaptive cross-term removal by combining seeded region growing.Compared to other methods,the new method can achieve cross-term removal without decreasing the TF concentration of the auto-term.Simulation and experimental data processing results show that the method is adaptive and is not constrained by the type or distribution of signals.And it performs well in low signal-to-noise ratio environments.展开更多
An abrasive water jet(AWJ)is commonly used to develop deep geothermal resources,such as drilling in hot dry rock(HDR).The influence of rock mineral properties,such as mineral types,mineral contents,and grain size,on t...An abrasive water jet(AWJ)is commonly used to develop deep geothermal resources,such as drilling in hot dry rock(HDR).The influence of rock mineral properties,such as mineral types,mineral contents,and grain size,on the formation of perforation by AWJ is unclear yet.In this study,we investigate AWJ impacts on three types of granite samples with different mineral fractions using a polarizing microscope and scanning electron microscope(SEM).The results show that when the grain size is doubled,the perforation depth increases by 16.22%under the same type of structure and properties.In general,fractures are more likely to be created at the position of rough surfaces caused by abrasive impact,and the form of fractures is determined by the mineral type.In addition,microstructure analysis shows that transgranular fractures typically pass through large feldspar particles and quartz removal occurs along mineral boundaries.The longitudinal extension of perforation depends mainly on the strong kinetic energy of the jet,while the lateral extension is controlled by the backflow.The results contribute to a better understanding of the process involved in the breaking of hard rock by abrasive jets during deep geothermal drilling.展开更多
基金Supported by Jiangsu Agricultural Science and Technology Innovation Fund(CX(12)5013)~~
文摘The pig-on-litter system is characterized by reduced environmental pollution and high-quality pork. It has won the support of the government and the acceptance of market. It is urgent to develop the supporting facilities and products to promote the comprehensive promotion of this technology. Based on the climatic and hydro- logical conditions in Jiangsu Province, we designed the removable deep-litter breed- ing shed. Its construction costs were lower than that of ordinary water-flushed pig- gery. In addition, this breeding system would not consolidate the land. The indoor ventilation and heat-conservation performances also met the requirements by pig-on- litter system. The removable shed can be promoted as an important supporting technology for the deep-litter breeding model in the eastern China.
文摘A new simplified removable ground test-bed was designed for testing a certainturbofan engine. The facilities are 5.5 m long, 1.5 m wide, 2.2 m high and not more than 4. 5 t ofits empty weight. There are four rubber wheels that could be towed. There is an independentelectrical measurement and control system to test the rotational speed of rotors, the gas pressureof the compressor, the exhaust gas temperature, etc. Cooperated with the oil truck and the electricpower supply truck, the turbofan engine could be preserved on the ground and started to the idlingregime. While running, the parameter of the engine could be recorded, disposed and displayed. Inaddition, the facilities were successfully applied to the plateau experiment in order to researchhow the atmosphere pressure affects the start of engines. Some data are given in the paper.
文摘Anti-ram bollard systems, which are installed around buildings and infrastructure, can prevent unauthorized vehicles from entering, maintain distance from vehicle-borne improvised explosive devices （VBIED） and reduce the corresponding damage. Compared with a fixed bollard system, a removable bollard system provides more flexibility as it can be removed when needed. This paper first proposes a new type of K4-rated removable anti-ram bollard system. To simulate the collision of a vehicle hitting the bollard system, a finite element model was then built and verified through comparison of numerical simulation results and existing experimental results. Based on the orthogonal design method, the factors influencing the safety and economy of this proposed system were examined and sorted according to their importance. An optimal design scheme was then produced. Finally, to validate the effectiveness of the proposed design scheme, four dynamic impact tests, including two front impact tests and two side impact tests, have been conducted according to BSI Specifications. The residual rotation angles of the specimen are smaller than 30~ and satisfy the requirements of the BSI Specification.
文摘In this paper we consider a nondivergent elliptic equation of second order whose leading coefficients are from some weight space. The sufficient condition of removability of a compact with respect to this equation in the weight space of Holder functions was found.
文摘Removable partial dentures (RPDs) (conventional and implant-supported) treatment is considered a viable option to replace missing teeth as inexpensively as possible, but it has limitations. Objectives: This study reports the effect of gender and location (maxilla vs. mandible) on the clinical performance of removable partial dentures (RPDs). Materials and Methods: A total of 100 Patients who had RPDs delivered between 1990-1995 were evaluated. A 4-point scoring system was used to assess seventeen criteria. These criteria include acceptance, stability, support, retention, adaptation, occlusion, integrity, and design of the pros-theses, rest and rest seat preparation, occlusal wear, esthetics, phonetics, tissue condition, mobility of abutments, gingival and plaque indices. The data were analyzed using Kruskal-Wallis and Mann-Whitney U non-parametric statistical tests. Results: The results showed that acceptance of RPDs was rated the lowest. Other reasons for failure were poor retention, lack of integrity of the prostheses and inadequate adaptation. Retention and design of major connectors attributed to Mandibular RPD failure. Success rate of 75% was observed in male compared with 67.2% for female. Maxillary RPDs showed a higher success rate (78%) compared with the mandibular (70.1%). No significant statistical difference in Alpha scores between female and male patients and between maxillary and mandibular RPDs (p < 0.05). Conclusions: The clinical performance of RPDs showed a higher success rate in male patients compared to female patients and the maxillary RPDs showed a higher success rate compared to mandibular.
文摘The aim of this study was to evaluate whether partial removable denture use indeed leads to improved oral health related quality of life and masticatory function. Materials and Methods: Partially edentulous patients presenting for removable denture treatment at the Prosthodontics Service in the Hospital Affiliated to Kinshasa University (Democratic Republic of Congo) were assessed for enrolment in this study. After applying exclusion criteria, 378 patients were included in the study, and randomly assigned into 2 groups. Oral health related quality of life (OHIP-23) and mastication time (MaT), number of chewing cycles (MaC), mastication frequency (MaF), and the sizes of the peanut fragments (FraS) were compared in both groups. Statistical significance was set at p < 0.05. Results: The average MaC, MaT, MaF, and FraS were 119 (± SD 53.70), 86.75 (±SD 35.35), 1.38 (±SD 0.25), and 3.3 (±SD 3.25) for the denture group and 77.9 (±SD 23.9), 60.2 (±SD 17.91), 1.29 (±SD 0.15), and 1.5 (±SD 0.7) for the non-denture group, respectively. Conclusion: The overall oral health related quality of life was best in the non-denture than denture.
文摘Objective: The goal of the removable partial denture is to restore impaired esthetics and masticatory function by replacing missing teeth. The aim of this study was to establish a possible correla-tion between removable partial denture in acrylic resin use after 5 years and dental diseases. Materials and Methods: Partially edentulous patients presenting for removable denture treatment at the Prosthodontics service of the Affiliated Hospital of Kinshasa University, Democratic Republic of Congo were assessed in this study. Patients were randomly assigned into 2 groups: Denture and non-denture group. Caries and periodontal diseases were compared between both groups. Statistical significance was set at p < 0.05. Results: The average age in the denture and non-denture-group was 53.15 (±SD 22.05) and 31.59 (±SD 11.98) years. Out of 160 teeth were decayed, both 110 teeth (68.75%) in the denture-group and 50 teeth (31.25%) in the non-denture group. The DMFT index calculated at start time of the study was 0.2 for both groups, after five years was 7.1 for the denture-group and 2.6 for the non-denture-group. The plaque index in the denture-group had an index of 1 and that of non-denture-group was 0.5. Conclusion: The relationship has been found between patients’ wearers a RPD and dental diseases.
基金Financial supports by the National Natural Science Foundation of China (Nos.51761135132 and 51822304) are sincerely acknowledged。
文摘A novel kind of fully bio-based PSAs we re obtained through the curing reaction between two components derived from the plant oils:carboxyl-terminated polyricinoleate(PRA) fro m the castor oil and epoxidized soybean oil(ESO).The get content,glass transition temperature(Tg),rheological behavior,tensile strength,creep resistance and 180° peel strength of the PSAs were feasibly tailored by adjusting the component ratio of ESO to PRA.At low cross-linking level,the PSAs behaved like a viscous liquid and did not possess enough cohesiveness to sustain the mechanical stress during peeling,The PSAs cross-linked at or near the optimal stoichiometric conditions displayed an adhesive(interfacial) failure between the substrate and the adhesive layer,which were associated with the lowest adhesion levels.The PSAs with the dosage amount of ESO ranging from 10.20 wt% were tacky and flexible,which exhibited 1800 peel strength ranging from 0.4~2.3 N/cm;and could be easily removed without any residues on the adherend.The process for the preparation of the fully bio-based PSAs was environmentally friendly without using any orga nic solve nt or other toxic chemical,herein showing the great potential as sustainable materials.
基金supported by the National Natural Science Foundation of China(Nos.22227810,22277020,22307061)China Postdoctoral Science Foundation(No.2022M721801)the Beijing Life Science Academy(No.2023000cc0130).
文摘Comprehensive Summary The strategy of removable glycosylation modification was used to overcome the low-efficiency problem encountered in the chemical synthesis of the mirror-image D-version of the immunoglobulin(Ig)-like domain of tropomyosin receptor kinase A(DlgCTrkA),a protein molecule needed for mirror-image screening of D-peptide ligands targeting this cell membrane receptor.It was found that O-linked-β-N-acetyl-D-glucosamine(O-GlcNAc)modification at^(D)Ser^(312),or^(D)Ser^(320)can significantly improve the efficiency of DlgCTrkA synthesis and folding,while O-GlcNAc modification at^(D)Ser^(330)showed barely any improvement.This study provides a new example demonstrating the power of the removable glycosylation modification strategy in the chemical synthesis and folding of difficult-to-obtain proteins.It also presents evidence that removable glycosylation modification at different sites would significantly affect the efficiency of protein folding promoted by this strategy.
基金supported by the National Science Foundation of China under Grant No.10831001the Fujian Provincial Department of Education under Grant No.JA08223
文摘Carvalho, Lucchesi and Murty proved that any 1-extendable graph G different from K2 and C2n has at least A（G） edge-disjoint removable ears, and any brick G distinct from K4 and C6 has at least A（G） - 2 removable edges, where A（G） denotes the maximum degree of G. In this paper, we improve the lower bounds for numbers of removable ears and removable edges of 1-extendable graphs. It is proved that any 1-extendable graph G different from K2 and C2n has at least x′（G） edge-disjoint removable ears, and any brick G distinct from Ka and Ce has at least x′（G） - 2 removable edges, where x′（G） denotes the edge-chromatic number of G. Key words 1-extendable graphs, removable ear, removable edge.
基金This work was financially supported by the National Natural Science Foundation of China （Nos. 21471016 and 21271023） and the 111 Project （No. B07012）.
文摘Rational design and simple synthesis of one-dimensional nanofibers with high specific surface areas and hierarchically porous structures are still challenging. In the present work, a novel strategy utilizing a thermally removable template was developed to synthesize hierarchically porous N-doped carbon nanofibers （HP-NCNFs） through the use of simple electrospinning technology coupled with subsequent pyrolysis. During the pyrolysis process, ZnO nanoparticles can be formed in situ and act as a thermally removable template due to their decomposition and sublimation under high-temperature conditions. The resulting HP-NCNFs have lengths of up to hundreds of micrometers with an average diameter of 300 nm and possess a hierarchically porous structure throughout. Such unique structures endow HP-NCNFs with a high specific surface area of up to 829.5 m2-g 1, which is 2.6 times higher than that （323.2 m2.g 1） of conventional N-doped carbon nanofibers （NCNFs）. Compared with conventional NCNFs, the HP-NCNF catalyst exhibited greatly enhanced catalytic performance and improved kinetics for the oxygen reduction reaction （ORR） in alkaline media. Moreover, the HP-NCNFs even showed better stability and stronger methanol crossover effect tolerance than the commerdal Pt-C catalyst. The optimized ORR performance can be attributed to the synergetic contribution of continuous and three-dimensional （3D） cross-linked structures, graphene-like structure on the edge of the HP- NCNFs, high specific surface area, and a hierarchically porous structure.
基金Supported by National Natural Science Foundation (No.49805005)partially by Research Foundation of Northern Jiaotong University (2002SM061)
文摘A Caccioppoli type estimate is established for a class of second order PDEs of divergence type, and its removable singularities of Hausdorff dimension greater than zero is obtained.
基金financially supported by the National Natural Science Foundation of China(Nos.92160301,92060203,52175415 and 52205475)the Science Center for Gas Turbine Project(No.P2023-B-IV-003-001)+1 种基金the Natural Science Foundation of Jiangsu Province(No.BK20210295)the Huaqiao University Engineering Research Center of Brittle Materials Machining(MOE,2023IME-001)。
文摘The remarkable ability of titanium alloys to preserve their superior physical and chemical characteristics when subjected to extreme conditions significantly enhances their importance in the aerospace,military,and medical sectors.However,conventional machining of titanium alloys leads to elevated tool wear,development of surface defects,and reduced machining efficiency due to their low heat conductivity,and chemical affinity.These issues can be somewhat counteracted by integrating ultrasonic vibration in the conventional machining of titanium alloys and also enhance sustainability.This review article offers a holistic evaluation of the influence of ultrasonic vibration-assisted milling and turning on cutting forces,temperature,tool wear,and surface integrity,encompassing surface morphology,surface roughness,surface residual stress,surface hardness,and surface tribological properties during titanium alloys machining.Furthermore,it investigates the sustainability aspect that has not been previously examined.Studies on the performance of ultrasonic-assisted cutting revealed several advantages,including decreased cutting forces and cutting temperature,improved tool life,and a better-machined surface during machining.Consequently,the sustainability factor is improved due to minimized energy consumption and residual waste.In conclusion,the key challenges and future prospects in the ultrasonic-assisted cutting of titanium alloys are also discussed.This review article provides beneficial knowledge for manufactur-ers and researchers regarding ultrasonic vibration-assisted cutting of titanium alloy and will play an important role in achieving sustainability in the industry.
基金supported by the National Natural Science Foundation of China ( 61503052, 61503050, 61603065, 61573075)Scientific and Technological Research Program of Chongqing Municipal Education Commission ( KJQN201801120, KJQN201801104,KJ17092060 )+1 种基金China Postdoctoral Science Foundation ( 2017M612911 )Chongqing Science and Technology Commission Technology Innovation and Application Demonstration Project ( cstc2018jscx-msybX0049)
文摘This paper investigates the propagation of computer viruses and establishes a novel propagation model. In contrast to the existing models,this model can directly indicate the impact of removable media and external computers on the propagation of computer virus. The stability results of equilibrium point are derived by Hurwitz criterion and Bendixson Dulac criterion. The effectiveness of the proposed results is shown by numerical simulation. In order to show the superiority of the proposed model,some comparisons with the existing models are presented. The acceptable threshold and the reasonable strategies for suppressing the propagation of computer virus are also suggested,respectively.
基金supported by the Special Funds for Chengde national innovation demonstration area construction of science and technology special project sustainable development agenda(No.202104F001)the National Basic Research Program of China(No.2019YFC0408602).
文摘Nitrogen removal from domestic sewage is usually limited by insufficient carbon source and electron donor.An economical solid carbon source was developed by composition of polyvinyl alcohol,sodium alginate,and corncob,which was utilized as external carbon source in the anaerobic anoxic oxic(AAO)-biofilter for the treatment of low carbon-to-nitrogen ratio domestic sewage,and the nitrogen removal was remarkably improved from 63.2%to 96.5%.Furthermore,the effluent chemical oxygen demand maintained at 35 mg/L or even lower,and the total nitrogenwas reduced to less than 2mg/L.Metagenomic analysis demonstrated that the microbial communities responsible for potential denitrification and organic matter degradation in both AAO and the biofilter reactors were mainly composed of Proteobacteria and Bacteroides,respectively.The solid carbon source addition resulted in relatively high abundance of functional enzymes responsible for NO_(3)^(−)-N to NO_(2)^(−)-N con-version in both AAO and the biofilter reactors,thus enabled stable reaction.The carbon source addition during glycolysis primarily led to the increase of genes associated with the metabolic conversion of fructose 1.6P2 to glycerol-3P The reactor maintained high abun-dance of genes related to the tricarboxylic acid cycle,and then guaranteed efficient carbon metabolism.The results indicate that the composite carbon source is feasible for denitri-fication enhancement of AAO-biofilter,which contribute to the theoretical foundation for practical nitrogen removal application.
基金support from the earmarked fund for XJARS(No.XJARS-06)the Bingtuan Science and Technology Program(Nos.2021DB019,2022CB001-01)+1 种基金the National Natural Science Foundation of China(No.42275014)the Guangdong Foundation for Program of Science and Technology Research,China(No.2023B1212060044)。
文摘Current research primarily focuses on emerging organic pollutants,with limited attention to emerging inorganic pollutants (EIPs).However,due to advances in detection technology and the escalating environmental and health challenges posed by pollution,there is a growing interest in treating waters contaminated with EIPs.This paper explores biochar characteristics and modification methods,encompassing physical,chemical,and biological approaches for adsorbing EIPs.It offers a comprehensive review of research advancements in employing biochar for EIPs remediation in water,outlines the adsorption mechanisms of EIPs by biochar,and presents an environmental and economic analysis.It can be concluded that using biochar for the adsorption of EIPs in wastewater exhibits promising potential.Nonetheless,it is noteworthy that certain EIPs like Au(III),Rh(III),Ir(III),Ru(III),Os(III),Sc(III),and Y(III),have not been extensively investigated regarding their adsorption onto biochar.This comprehensive review will catalyze further inquiry into the biochar-based adsorption of EIPs,addressing current research deficiencies and advancing the practical implementation of biochar as a potent substrate for EIP removal from wastewater streams.
基金supported by the National Natural Science Foundation of China(Nos.22206146,22006079,and U21A20524)the Fundamental Research Funds for the Central Universities,the Youth Innovation Promotion Association of Chinese Academy of Sciences,the Fundamental Research Program of Shanxi Province(No.202103021223280)+1 种基金the Special Fund for Science and Technology Innovation Teams of Shanxi Province(No.202204051002026)the Natural Science Foundation of Shandong Province(No.ZR2021QB133).
文摘Owing to the complexity of multicomponent gases,developing multifunctional catalysts for synergistic removal of benzene and toluene remains challenging.The spinel MMn_(2)O_(4)(M=Co,Ni,or Cu)catalysts were successfully synthesized via the sol–gel method and tested for their catalytic performance for simultaneous degradation of benzene and toluene.The CuMn_(2)O_(4)sample exhibited the best catalytic performance,the conversion of benzene reached 100%at 350℃,and toluene conversion reached 100%at 250℃.XRD,N_(2)adsorption-desorption,HRTEM-EDS,ED-XRF,Raman spectroscopy,H_(2)-TPR,NH_(3)-TPD,O_(2)-TPD and XPS were used to characterize the physical and chemical properties of MMn_(2)O_(4)catalysts.The excellent redox properties,high concentration of surface Mn4+,and adsorption of oxygen species over the CuMn_(2)O_(4)sample facilitated the simultaneous and efficient removal of benzene and toluene.Additionally,in situ DRIFTS illustrated the intermediate species and reaction mechanism for the synergetic catalytic oxidation of benzene and toluene.Notably,as an effective catalytic material,spinel oxide exhibited excellent synergistic degradation performance for benzene and toluene,providing some insight for the development of efficient multicomponent VOC catalysts.
基金supported by the National Natural Science Foundation of China(52100093,52270128,and 52261135627)the Guangdong Basic and Applied Basic Research Foundation(2023A1515011734 and 2021B1515120068)+2 种基金the Municipal Science and Technology Innovation Council of the Shen-zhen Government(KCXFZ20211020163556020 and SGDX20230116092359002)the Research Grants Council(17210219)the Innovation and Technology Fund(ITS/242/20FP)of the Hong Kong SAR Government。
文摘The rapidly growing demand for lithium iron phosphate(LiFePO_(4))as the cathode material of lithium-ion batteries(LIBs)has aggravated the scarcity of phosphorus(P)reserves on Earth.This study introduces an environmentally friendly and economical method of P recovery from municipal wastewater,providing the P source for LiFePO_(4) cathodes.The novel approach utilizes the sludge of Fe-coagulant-based chemical P removal(CPR)in wastewater treatment.After a sintering treatment with acid washing,the CPR sludge,enriched with P and Fe,transforms into purified P-Fe oxides(Fe2.1P1.0O5.6).These oxides can substitute up to 35%of the FePO_(4) reagent as precursor,producing a carbon-coated LiFePO_(4)(LiFePO_(4)/C)cathode with a specific discharge capacity of 114.9 mA·h·g^(-1)at current density of 17 mA·g^(-1)),and cycle stability of 99.2%after 100 cycles.The enhanced cycle performance of the as-prepared LiFePO_(4)/C cathode may be attributed to the incorporations of impurities(such as Ca^(2+)and Na^(+))from sludge,with improved stability of crystal structure.Unlike conventional P-fertilizers,this P recovery technology converts 100%of P in CPR sludge into the production of value-added LiFePO_(4)/C cathodes.The recovered P from municipal wastewater can meet up to 35%of the P demand in the Chinese LIBs industry,offering a cost-effective solution for addressing the pressing challenges of P scarcity.
基金Supported by the National Natural Science Foundation of China(62201171).
文摘Wigner-Ville distribution(WVD)is widely used in the field of signal processing due to its excellent time-frequency(TF)concentration.However,WVD is severely limited by the cross-term when working with multicomponent signals.In this paper,we analyze the property differences between auto-term and cross-term in the one-dimensional sequence and the two-dimensional plane and approximate entropy and Rényi entropy are employed to describe them,respectively.Based on this information,we propose a new method to achieve adaptive cross-term removal by combining seeded region growing.Compared to other methods,the new method can achieve cross-term removal without decreasing the TF concentration of the auto-term.Simulation and experimental data processing results show that the method is adaptive and is not constrained by the type or distribution of signals.And it performs well in low signal-to-noise ratio environments.
基金supported by the Postdoctoral Fellowship Program of CPSF(Grant No.GZC20233326)the Chongqing Science Fund for Distinguished Young Scholars(Grant No.CSTB2022NSCQJQX0028)the National Natural Science Foundation of China(Grant Nos.U23A20597,52274112).
文摘An abrasive water jet(AWJ)is commonly used to develop deep geothermal resources,such as drilling in hot dry rock(HDR).The influence of rock mineral properties,such as mineral types,mineral contents,and grain size,on the formation of perforation by AWJ is unclear yet.In this study,we investigate AWJ impacts on three types of granite samples with different mineral fractions using a polarizing microscope and scanning electron microscope(SEM).The results show that when the grain size is doubled,the perforation depth increases by 16.22%under the same type of structure and properties.In general,fractures are more likely to be created at the position of rough surfaces caused by abrasive impact,and the form of fractures is determined by the mineral type.In addition,microstructure analysis shows that transgranular fractures typically pass through large feldspar particles and quartz removal occurs along mineral boundaries.The longitudinal extension of perforation depends mainly on the strong kinetic energy of the jet,while the lateral extension is controlled by the backflow.The results contribute to a better understanding of the process involved in the breaking of hard rock by abrasive jets during deep geothermal drilling.
