The capital of Guinea, Conakry, faces a notable difficulty due to a water shortage, which is worsened by the rapid increase in population and urban development. The Guinean Water Company (SEG) faces challenges in supp...The capital of Guinea, Conakry, faces a notable difficulty due to a water shortage, which is worsened by the rapid increase in population and urban development. The Guinean Water Company (SEG) faces challenges in supplying water to the entire city due to its limited area of approximately 420 km<sup>2</sup> and a population of 2 million. Moreover, the population growth rate is anticipated to increase dramatically, exacerbating the difficulty of fulfilling future water requirements. As a result, this study employs data from the Knoema website and the Institute of National Statistics of Guinea (INS) to examine the water production and distribution process by the SEG. The study examines the challenges related to water scarcity in Conakry and suggests strategies to assist the city in managing the present circumstances and planning for the future. The primary objective is to get a long-lasting water supply and uphold water quality to advance public health.展开更多
Au/Ni/n-type 4H–SiC Schottky alpha particle detectors are fabricated and annealed at temperatures between 400℃ and 700℃ to investigate the effects of thermal stability of the Schottky contact on the structural and ...Au/Ni/n-type 4H–SiC Schottky alpha particle detectors are fabricated and annealed at temperatures between 400℃ and 700℃ to investigate the effects of thermal stability of the Schottky contact on the structural and electrical properties of the detectors. At the annealing temperature of 500?C, the two nickel silicides(i.e., Ni_(31)Si_(12) and Ni_2Si) are formed at the interface and result in the formation of an inhomogeneous Schottky barrier. By increasing the annealing temperature,the Ni_(31)Si_(12) transforms into the more stable Ni_2Si. The structural evolution of the Schottky contact directly affects the electrical properties and alpha particle energy resolutions of the detectors. A better energy resolution of 2.60% is obtained for 5.48-MeV alpha particles with the detector after being annealed at 600℃. As a result, the Au/Ni/n-type 4 H–SiC Schottky detector shows a good performance after thermal treatment at temperatures up to 700℃.展开更多
Complete high-resolution light curves of GRB 080319B observed by Swift present an opportunity for detailed temporal analysis of prompt optical emission. With a two-component distribution of initial Lorentz factors, we...Complete high-resolution light curves of GRB 080319B observed by Swift present an opportunity for detailed temporal analysis of prompt optical emission. With a two-component distribution of initial Lorentz factors, we simulate the dynamical process of shells being ejected from the central engine in the framework of the internal shock model. The emitted radiations are decomposed into different frequency ranges for a temporal correlation analysis between the light curves in different energy bands. The resulting prompt optical and gamma-ray emissions show similar temporal profiles, with both showing a superposition of a component with slow variability and a component with fast variability, except that the gamma-ray light curve is much more variable than its optical counterpart. The variability in the simulated light curves and the strong correlation with a time lag between the optical and gamma-ray emissions are in good agreement with observations of GRB 080319B. Our simulations suggest that the variations seen in the light curves stem from the temporal structure of the shells injected from the central engine of gamma-ray bursts. Future observations with high temporal resolution of prompt optical emission from GRBs, e.g., by UFFOPathfinder and SVOM-GWAC, will provide a useful tool for investigating the central engine activity.展开更多
A new developed external loop airlift slurry reactor, which was integrated with gas–liquid–solid three-phase mixing, mass transfer, and liquid–solid separation simultaneously, was deemed to be a promising slurry re...A new developed external loop airlift slurry reactor, which was integrated with gas–liquid–solid three-phase mixing, mass transfer, and liquid–solid separation simultaneously, was deemed to be a promising slurry reactor due to its prominent advantages such as achieving continuous separation of clear liquid from slurry and cyclic utilization of solid particles without any extra energy, energy-saving, and intrinsic safety design. The principal operating parameters, including gas separator volume, handling capacity, and superficial gas velocity, are systematically investigated here to promote the capabilities of mixing, mass transfer, and yield in the pilot external loop airlift slurry reactor. The influences of top clearance and throughput of the clear liquid on flow regime and gas holdup in the riser, liquid circulating velocity, and volumetric mass transfer coefficient with a typical high solid holdup and free of particles are examined experimentally. It was found that increasing the gas separator volume could promote the liquid circulating velocity by about 14.0% at most. Increasing the handling capacity of the clear liquid from 0.9 m3·h-1 to 3.0 m3·h-1 not only could increase the output without any adverse consequences, but also could enhance the liquid circulating velocity as much as 97.3%. Typical operating conditions investigated here can provide some necessary data and guidelines for this new external loop airlift slurry reactor to upgrade its performances.展开更多
BACKGROUND Well-differentiated liposarcoma is the second most common pathologic type of retroperitoneal sarcoma.It is characterized by a huge mass,but multiple organ invasions are common.Surgery is the only treatment ...BACKGROUND Well-differentiated liposarcoma is the second most common pathologic type of retroperitoneal sarcoma.It is characterized by a huge mass,but multiple organ invasions are common.Surgery is the only treatment option for potential cure.Hyper-accuracy three-dimensional(3D)reconstruction is widely used in robotic partly nephrectomy owing to its ability to visualize overlapping anatomy.CASE SUMMARY A 54-year-old man was admitted for progressive abdominal distension over the preceding 2 mo.Computed tomography revealed a 32 cm×21 cm×12 cm lipomatous mass.Hyper-accuracy 3D reconstruction was performed because of the complex relationship between the mass and nearby tissue.The patient underwent surgical resection,and the tumor did not recur for over 16 mo.CONCLUSION Hyper-accuracy 3D reconstruction is useful for operative planning owing to its intuitiveness and precise determination of anatomical structures in both tumors and nearby tissues.展开更多
Objective:To study the effect of Baiban Ointment on gene expression profile of vulvar lichen sclerosus before and after treatment,and to provide theoretical basis for the early diagnosis and clinical treatment of vulv...Objective:To study the effect of Baiban Ointment on gene expression profile of vulvar lichen sclerosus before and after treatment,and to provide theoretical basis for the early diagnosis and clinical treatment of vulvar lichen sclerosus.Methods:Nine patients with vulvar lichen sclerosus diagnosed pathologically were selected as the study object,and the Baiban ointment was applied locally for 3 months.Gene chip technology was used to detect the vulva skin tissue in the same area before and after treatment,and the peripheral normal skin was used as the normal control group to analyze the change of gene expression profile.FC and P values were used as research indicators,and the standard of differential expression was FC value≥1.5,P value<0.05.The differentially expressed genes were screened,and GO analysis and KEGG database gene pathway analysis were carried out.Results:Compared with the normal control group,there were 22 differentially expressed genes in Group A before treatment,of which 21 were up-regulated and 1 was down regulated;compared with Group B before treatment,there were 23 differentially expressed genes,all of which were up regulated.The differentially expressed genes related to Baiban ointment treatment included TBK1、STAT1、ITGAM、VCAN、PRKACB、PROM1、PLAT、SERPINA1.Go analysis showed that the up-regulated differential genes were mainly concentrated in the extracellular exosome,cytosol,extracellular space,Golgi apparatus and other cellular component,using the biological process such as positive regulation of cell metabolism,signal transduction regulation,cell adhesion,etc.,to play a role in protein binding,enzyme activity regulation and other molecular functions.KEGG signaling pathway showed that the differentially expressed genes were significantly enriched in Toll like receptor signaling pathway,Nod like receptor signaling pathway and Fc RI signaling pathway,all of which were up-regulated signaling pathways.Among them,Toll like receptor signaling pathway and Nod like receptor signaling pathway are most closely related to the disease.Conclusion:Baiban ointment may play a role in regulating metabolism,inflammation and immune response by regulating the expression of related genes,affecting the signal transduction such as Toll like receptor signal pathway.The pathway and the genes screened in this study will provide a direction for the future study of this disease.展开更多
Backgrounds: Surgical interventions especially minimally invasive treatments are recommended for symptomatic midline prostatic cysts. The endoscopic unroofing of cysts close to urethra is easy and simple, but it has l...Backgrounds: Surgical interventions especially minimally invasive treatments are recommended for symptomatic midline prostatic cysts. The endoscopic unroofing of cysts close to urethra is easy and simple, but it has little effect on the large cysts and cysts lying deeply, in contrast with the laparoscopic approach. Therefore, the selection of minimally invasive therapeutic approaches is important. The aim of this study is to describe our experience in the diagnosis and selection of minimally invasive treatment for midline prostatic cyst. Methods: 15 cases of midline prostatic cyst were studied.10 cases presented with prostatitis-like symptoms, 1 with dysuria and acute urinary retention, 3 with secondary infertility and the rest 1 with hemospermia. 6 patients presented with small cysts (≤2 cm × 2 cm) close to urethra and underwent transurethral unroofing. The other 9 patients with large cysts (>2 cm × 2 cm) or cysts lying closely behind the prostate received the laparoscopic excision. Results: The average duration of transurethral unroofing and laparoscopic excision was 39 mins and 118 mins respectively, whereas the average time of hospitalization was 2.7 days and 4.5 days respectively. After a follow-up of 21 months, all cases were treated successfully without complications and recurrence. Their prostatitis-like symptoms disappeared, and the three patients presented with secondary infertility achieved conception within one year after the operation. Conclusions: A midline prostatic cyst can present with chronic prostatitis-like symptoms and secondary infertility. It can be cured by minimally invasive treatments, but these procedures should be carefully selected according to the size and location of the cyst.展开更多
The hierarchical structure can significantly improve the diffusion efficiency of the catalyst and regulate the product distribution. Therefore, the preparation of hierarchical SAPO-34 molecular sieve has been a hot re...The hierarchical structure can significantly improve the diffusion efficiency of the catalyst and regulate the product distribution. Therefore, the preparation of hierarchical SAPO-34 molecular sieve has been a hot research topic. With Cetyltrimethyl Ammonium Bromide (CTAB) and Diethylamine (DEA) as templates, a two-step crystallization process was employed to synthesize hierarchical SAPO-34 molecular sieves. We found that the aging process is vital for the formation of pure phase SAPO-34. It was investigated the relationship of crystallinity trend and mesoporous content with the crystallization time. The results showed that the prolongation of crystallization time was beneficial to enhance the crystallinity of the molecular sieve, but unfavourable to the retention of mesoporous structure. The formation process of hierarchical SAPO-34 molecular sieve involved agglomeration, disintegration, crystallization, re-agglomeration and growth. The hierarchical SAPO-34 molecular sieve with a satisfactory crystallinity and considerable mesoporous structure could be obtained after 36 hours of crystallization. Moreover, the sample had the most suitable acid strength as well as acid amount. The catalytic activity was investigated by catalytic dimethyl ether (DME) to olefin (DTO) reaction. It revealed that the conversion of DME and the selectivity to olefins over the hierarchical SAPO-34 molecular sieve were significantly enhanced with comparison to that over microporous SAPO-34 molecular sieve. The amount of coke deposition of the hierarchical SAPO-34 molecular sieve (14.2%) was lower than that over the microporous molecular sieve (16.5%). Meanwhile, the propylene selectivity of hierarchical SAPO-34 was higher than that of microporous SAPO-34 in the whole reaction. In a word, the hierarchical SAPO-34 molecular sieve synthesized in this study showed a longer catalytic life, higher coke deposition resistance and higher propylene selectivity.展开更多
The magnesium matrix composites(MMCs) formed by introducing reinforcements to magnesium alloys overcome the limitations of the mechanical properties to a certain extent, presenting unique and excellent properties that...The magnesium matrix composites(MMCs) formed by introducing reinforcements to magnesium alloys overcome the limitations of the mechanical properties to a certain extent, presenting unique and excellent properties that any component does not have, such as high specific stiffness and specific strength, good dimensional stability, outstanding shock absorption performance, excellent electromagnetic shielding and hydrogen storage characteristics, etc. As an emerging manufacturing technology, additive manufacturing(AM) is based on the design of threedimensional(3D) data model to obtain 3D objects through layer-by-layer processing, which possesses the advantages of short manufacturing cycle, high material utilization rate, high degree of design freedom, excellent mechanical properties and the ability to fabricate complex structural components. Combining the high stiffness and high strength properties of MMCs and the technical advantages of AM forming complex structural parts with high performance, the prepared AM MMCs have huge potential advantages and broad application prospects in new high-tech industries such as automobile, aerospace, consumer electronics and biomedicine, etc. This paper reviews the research progress in the field of AM MMCs, mainly introduces the main AM technologies, including selective laser melting(SLM), electron beam selective melting(EBSM), laser engineered net shaping(LENS) and wire and arc additive manufacturing(WAAM). The formation mechanism and control methods of the typical defects including balling effect, porosity, poor fusion, loss of alloy elements and cracks produced during AM are discussed. The main challenges of AM MMCs are proposed from the aspects of composition design and the preparation of powder raw material. The relationship between the microstructure and mechanical properties, corrosion performance and biocompatibility of AM MMCs are elaborated in detail. The application potential of AM MMCs in various fields at present and in the future is introduced. Finally, the development direction and urgent problems to be solved in the AM MMCs are prospected.展开更多
文摘The capital of Guinea, Conakry, faces a notable difficulty due to a water shortage, which is worsened by the rapid increase in population and urban development. The Guinean Water Company (SEG) faces challenges in supplying water to the entire city due to its limited area of approximately 420 km<sup>2</sup> and a population of 2 million. Moreover, the population growth rate is anticipated to increase dramatically, exacerbating the difficulty of fulfilling future water requirements. As a result, this study employs data from the Knoema website and the Institute of National Statistics of Guinea (INS) to examine the water production and distribution process by the SEG. The study examines the challenges related to water scarcity in Conakry and suggests strategies to assist the city in managing the present circumstances and planning for the future. The primary objective is to get a long-lasting water supply and uphold water quality to advance public health.
基金Project supported by the National Natural Science Foundation of China(Grant Nos.11675198,61574026,and 11405017)the National Key Research and Development Program of China(Grant Nos.2016YFB0400600 and 2016YFB0400601)+1 种基金the Natural Science Foundation of Liaoning Province of China(Grant Nos.201602453 and 201602176)the China Postdoctoral Science Foundation(Grant No.2016M591434)
文摘Au/Ni/n-type 4H–SiC Schottky alpha particle detectors are fabricated and annealed at temperatures between 400℃ and 700℃ to investigate the effects of thermal stability of the Schottky contact on the structural and electrical properties of the detectors. At the annealing temperature of 500?C, the two nickel silicides(i.e., Ni_(31)Si_(12) and Ni_2Si) are formed at the interface and result in the formation of an inhomogeneous Schottky barrier. By increasing the annealing temperature,the Ni_(31)Si_(12) transforms into the more stable Ni_2Si. The structural evolution of the Schottky contact directly affects the electrical properties and alpha particle energy resolutions of the detectors. A better energy resolution of 2.60% is obtained for 5.48-MeV alpha particles with the detector after being annealed at 600℃. As a result, the Au/Ni/n-type 4 H–SiC Schottky detector shows a good performance after thermal treatment at temperatures up to 700℃.
基金Supported by the National Natural Science Foundation of China
文摘Complete high-resolution light curves of GRB 080319B observed by Swift present an opportunity for detailed temporal analysis of prompt optical emission. With a two-component distribution of initial Lorentz factors, we simulate the dynamical process of shells being ejected from the central engine in the framework of the internal shock model. The emitted radiations are decomposed into different frequency ranges for a temporal correlation analysis between the light curves in different energy bands. The resulting prompt optical and gamma-ray emissions show similar temporal profiles, with both showing a superposition of a component with slow variability and a component with fast variability, except that the gamma-ray light curve is much more variable than its optical counterpart. The variability in the simulated light curves and the strong correlation with a time lag between the optical and gamma-ray emissions are in good agreement with observations of GRB 080319B. Our simulations suggest that the variations seen in the light curves stem from the temporal structure of the shells injected from the central engine of gamma-ray bursts. Future observations with high temporal resolution of prompt optical emission from GRBs, e.g., by UFFOPathfinder and SVOM-GWAC, will provide a useful tool for investigating the central engine activity.
基金supported by the National Natural Science Foundation of China (Nos. 21808234,21878318)the DNL Cooperation Fund,CAS(DNL201902)+3 种基金“Transformational Technologies for Clean Energy and Demonstration”, Strategic Priority Research Program of the CAS(XDA21060400)QIBEBT and Dalian National Laboratory for Clean Energy of the CAS(QIBEBT ZZBS201803,QIBEBT I201907)CAS Key Technology Talent ProgramProject of CNPC-DICP Joint Research Center。
文摘A new developed external loop airlift slurry reactor, which was integrated with gas–liquid–solid three-phase mixing, mass transfer, and liquid–solid separation simultaneously, was deemed to be a promising slurry reactor due to its prominent advantages such as achieving continuous separation of clear liquid from slurry and cyclic utilization of solid particles without any extra energy, energy-saving, and intrinsic safety design. The principal operating parameters, including gas separator volume, handling capacity, and superficial gas velocity, are systematically investigated here to promote the capabilities of mixing, mass transfer, and yield in the pilot external loop airlift slurry reactor. The influences of top clearance and throughput of the clear liquid on flow regime and gas holdup in the riser, liquid circulating velocity, and volumetric mass transfer coefficient with a typical high solid holdup and free of particles are examined experimentally. It was found that increasing the gas separator volume could promote the liquid circulating velocity by about 14.0% at most. Increasing the handling capacity of the clear liquid from 0.9 m3·h-1 to 3.0 m3·h-1 not only could increase the output without any adverse consequences, but also could enhance the liquid circulating velocity as much as 97.3%. Typical operating conditions investigated here can provide some necessary data and guidelines for this new external loop airlift slurry reactor to upgrade its performances.
基金the National Natural Science Foundation of China,No.81272833.
文摘BACKGROUND Well-differentiated liposarcoma is the second most common pathologic type of retroperitoneal sarcoma.It is characterized by a huge mass,but multiple organ invasions are common.Surgery is the only treatment option for potential cure.Hyper-accuracy three-dimensional(3D)reconstruction is widely used in robotic partly nephrectomy owing to its ability to visualize overlapping anatomy.CASE SUMMARY A 54-year-old man was admitted for progressive abdominal distension over the preceding 2 mo.Computed tomography revealed a 32 cm×21 cm×12 cm lipomatous mass.Hyper-accuracy 3D reconstruction was performed because of the complex relationship between the mass and nearby tissue.The patient underwent surgical resection,and the tumor did not recur for over 16 mo.CONCLUSION Hyper-accuracy 3D reconstruction is useful for operative planning owing to its intuitiveness and precise determination of anatomical structures in both tumors and nearby tissues.
基金Harbin Science and technology plan project(NO.2016RAXJ060)
文摘Objective:To study the effect of Baiban Ointment on gene expression profile of vulvar lichen sclerosus before and after treatment,and to provide theoretical basis for the early diagnosis and clinical treatment of vulvar lichen sclerosus.Methods:Nine patients with vulvar lichen sclerosus diagnosed pathologically were selected as the study object,and the Baiban ointment was applied locally for 3 months.Gene chip technology was used to detect the vulva skin tissue in the same area before and after treatment,and the peripheral normal skin was used as the normal control group to analyze the change of gene expression profile.FC and P values were used as research indicators,and the standard of differential expression was FC value≥1.5,P value<0.05.The differentially expressed genes were screened,and GO analysis and KEGG database gene pathway analysis were carried out.Results:Compared with the normal control group,there were 22 differentially expressed genes in Group A before treatment,of which 21 were up-regulated and 1 was down regulated;compared with Group B before treatment,there were 23 differentially expressed genes,all of which were up regulated.The differentially expressed genes related to Baiban ointment treatment included TBK1、STAT1、ITGAM、VCAN、PRKACB、PROM1、PLAT、SERPINA1.Go analysis showed that the up-regulated differential genes were mainly concentrated in the extracellular exosome,cytosol,extracellular space,Golgi apparatus and other cellular component,using the biological process such as positive regulation of cell metabolism,signal transduction regulation,cell adhesion,etc.,to play a role in protein binding,enzyme activity regulation and other molecular functions.KEGG signaling pathway showed that the differentially expressed genes were significantly enriched in Toll like receptor signaling pathway,Nod like receptor signaling pathway and Fc RI signaling pathway,all of which were up-regulated signaling pathways.Among them,Toll like receptor signaling pathway and Nod like receptor signaling pathway are most closely related to the disease.Conclusion:Baiban ointment may play a role in regulating metabolism,inflammation and immune response by regulating the expression of related genes,affecting the signal transduction such as Toll like receptor signal pathway.The pathway and the genes screened in this study will provide a direction for the future study of this disease.
文摘Backgrounds: Surgical interventions especially minimally invasive treatments are recommended for symptomatic midline prostatic cysts. The endoscopic unroofing of cysts close to urethra is easy and simple, but it has little effect on the large cysts and cysts lying deeply, in contrast with the laparoscopic approach. Therefore, the selection of minimally invasive therapeutic approaches is important. The aim of this study is to describe our experience in the diagnosis and selection of minimally invasive treatment for midline prostatic cyst. Methods: 15 cases of midline prostatic cyst were studied.10 cases presented with prostatitis-like symptoms, 1 with dysuria and acute urinary retention, 3 with secondary infertility and the rest 1 with hemospermia. 6 patients presented with small cysts (≤2 cm × 2 cm) close to urethra and underwent transurethral unroofing. The other 9 patients with large cysts (>2 cm × 2 cm) or cysts lying closely behind the prostate received the laparoscopic excision. Results: The average duration of transurethral unroofing and laparoscopic excision was 39 mins and 118 mins respectively, whereas the average time of hospitalization was 2.7 days and 4.5 days respectively. After a follow-up of 21 months, all cases were treated successfully without complications and recurrence. Their prostatitis-like symptoms disappeared, and the three patients presented with secondary infertility achieved conception within one year after the operation. Conclusions: A midline prostatic cyst can present with chronic prostatitis-like symptoms and secondary infertility. It can be cured by minimally invasive treatments, but these procedures should be carefully selected according to the size and location of the cyst.
文摘The hierarchical structure can significantly improve the diffusion efficiency of the catalyst and regulate the product distribution. Therefore, the preparation of hierarchical SAPO-34 molecular sieve has been a hot research topic. With Cetyltrimethyl Ammonium Bromide (CTAB) and Diethylamine (DEA) as templates, a two-step crystallization process was employed to synthesize hierarchical SAPO-34 molecular sieves. We found that the aging process is vital for the formation of pure phase SAPO-34. It was investigated the relationship of crystallinity trend and mesoporous content with the crystallization time. The results showed that the prolongation of crystallization time was beneficial to enhance the crystallinity of the molecular sieve, but unfavourable to the retention of mesoporous structure. The formation process of hierarchical SAPO-34 molecular sieve involved agglomeration, disintegration, crystallization, re-agglomeration and growth. The hierarchical SAPO-34 molecular sieve with a satisfactory crystallinity and considerable mesoporous structure could be obtained after 36 hours of crystallization. Moreover, the sample had the most suitable acid strength as well as acid amount. The catalytic activity was investigated by catalytic dimethyl ether (DME) to olefin (DTO) reaction. It revealed that the conversion of DME and the selectivity to olefins over the hierarchical SAPO-34 molecular sieve were significantly enhanced with comparison to that over microporous SAPO-34 molecular sieve. The amount of coke deposition of the hierarchical SAPO-34 molecular sieve (14.2%) was lower than that over the microporous molecular sieve (16.5%). Meanwhile, the propylene selectivity of hierarchical SAPO-34 was higher than that of microporous SAPO-34 in the whole reaction. In a word, the hierarchical SAPO-34 molecular sieve synthesized in this study showed a longer catalytic life, higher coke deposition resistance and higher propylene selectivity.
基金financially supported by the Defense Industrial Technology Development Program (no.JCKY2021601B203)Ningbo Yongjiang Talent Project (no.YJ0222012)Ningbo Beilun District “Strong Port and Strong District Talent Introduction” Project (no.QG0222002)。
文摘The magnesium matrix composites(MMCs) formed by introducing reinforcements to magnesium alloys overcome the limitations of the mechanical properties to a certain extent, presenting unique and excellent properties that any component does not have, such as high specific stiffness and specific strength, good dimensional stability, outstanding shock absorption performance, excellent electromagnetic shielding and hydrogen storage characteristics, etc. As an emerging manufacturing technology, additive manufacturing(AM) is based on the design of threedimensional(3D) data model to obtain 3D objects through layer-by-layer processing, which possesses the advantages of short manufacturing cycle, high material utilization rate, high degree of design freedom, excellent mechanical properties and the ability to fabricate complex structural components. Combining the high stiffness and high strength properties of MMCs and the technical advantages of AM forming complex structural parts with high performance, the prepared AM MMCs have huge potential advantages and broad application prospects in new high-tech industries such as automobile, aerospace, consumer electronics and biomedicine, etc. This paper reviews the research progress in the field of AM MMCs, mainly introduces the main AM technologies, including selective laser melting(SLM), electron beam selective melting(EBSM), laser engineered net shaping(LENS) and wire and arc additive manufacturing(WAAM). The formation mechanism and control methods of the typical defects including balling effect, porosity, poor fusion, loss of alloy elements and cracks produced during AM are discussed. The main challenges of AM MMCs are proposed from the aspects of composition design and the preparation of powder raw material. The relationship between the microstructure and mechanical properties, corrosion performance and biocompatibility of AM MMCs are elaborated in detail. The application potential of AM MMCs in various fields at present and in the future is introduced. Finally, the development direction and urgent problems to be solved in the AM MMCs are prospected.
