Metamaterials based on effective media can be used to produce a number of unusual physical properties(for example,negative refraction and invisibility cloaking)because they can be tailored with effective medium parame...Metamaterials based on effective media can be used to produce a number of unusual physical properties(for example,negative refraction and invisibility cloaking)because they can be tailored with effective medium parameters that do not occur in nature.Recently,the use of coding metamaterials has been suggested for the control of electromagnetic waves through the design of coding sequences using digital elements‘0’and‘1,'which possess opposite phase responses.Here we propose the concept of an anisotropic coding metamaterial in which the coding behaviors in different directions are dependent on the polarization status of the electromagnetic waves.We experimentally demonstrate an ultrathin and flexible polarization-controlled anisotropic coding metasurface that functions in the terahertz regime using specially designed coding elements.By encoding the elements with elaborately designed coding sequences(both 1-bit and 2-bit sequences),the x-and y-polarized waves can be anomalously reflected or independently diffused in three dimensions.The simulated far-field scattering patterns and near-field distributions are presented to illustrate the dual-functional performance of the encoded metasurface,and the results are consistent with the measured results.We further demonstrate the ability of the anisotropic coding metasurfaces to generate a beam splitter and realize simultaneous anomalous reflections and polarization conversions,thus providing powerful control of differently polarized electromagnetic waves.The proposed method enables versatile beam behaviors under orthogonal polarizations using a single metasurface and has the potential for use in the development of interesting terahertz devices.展开更多
The terahertz region is a special region of the electromagnetic spectrum that incorporates the advantages of both microwaves and infrared light waves.In the past decade,metamaterials with effective medium parameters o...The terahertz region is a special region of the electromagnetic spectrum that incorporates the advantages of both microwaves and infrared light waves.In the past decade,metamaterials with effective medium parameters or gradient phases have been studied to control terahertz waves and realize functional devices.Here,we present a new approach to manipulate terahertz waves by using coding metasurfaces that are composed of digital coding elements.We propose a general coding unit based on a Minkowski closed-loop particle that is capable of generating 1-bit coding(with two phase states of 0 and 180°),2-bit coding(with four phase states of 0,90°,180°,and 270°),and multi-bit coding elements in the terahertz frequencies by using different geometric scales.We show that multi-bit coding metasurfaces have strong abilities to control terahertz waves by designing-specific coding sequences.As an application,we demonstrate a new scattering strategy of terahertz waves—broadband and wide-angle diffusion—using a 2-bit coding metasurface with a special coding design and verify it by both numerical simulations and experiments.The presented method opens a new route to reducing the scattering of terahertz waves.展开更多
BACKGROUND Systemic inflammation and nutrition status play an important role in cancer metastasis.The combined index of hemoglobin,albumin,lymphocyte,and platelet(HALP),consisting of haemoglobin,albumin,lymphocytes,an...BACKGROUND Systemic inflammation and nutrition status play an important role in cancer metastasis.The combined index of hemoglobin,albumin,lymphocyte,and platelet(HALP),consisting of haemoglobin,albumin,lymphocytes,and platelets,is considered as a novel marker to reflect both systemic inflammation and nutrition status.However,no studies have investigated the relationship between HALP and survival of patients with pancreatic cancer following radical resection.AIM To evaluate the prognostic value of preoperative HALP in pancreatic cancer patients.METHODS The preoperative serum levels of hemoglobin,albumin,lymphocyte counts,and platelet counts were routinely detected in 582 pancreatic adenocarcinoma patients who underwent radical resection.The relationship between postoperative survival and the preoperative level of HALP was investigated.RESULTS Low levels of HALP were significantly associated with lymph node metastasis(P=0.002),poor tumor differentiation(P=0.032),high TNM stage(P=0.008),female patients(P=0.005)and tumor location in the head of the pancreas(P<0.001).Low levels of HALP were associated with early recurrence[7.3 mo vs 16.3 mo,P<0.001 for recurrence-free survival(RFS)]and short survival[11.5 mo vs 23.6 mo,P<0.001 for overall survival(OS)]in patients with resected pancreatic adenocarcinoma.A low level of HALP was an independent risk factor for early recurrence and short survival irrespective of sex and tumor location.CONCLUSION Low levels of HALP may be a significant risk factor for RFS and OS in patients with resected pancreatic cancer.展开更多
Laser melting deposition with WC addition has been developed to fabricate high-strength CrMnFeCoNibased high-entropy alloys-based composites.By this technique,a microstructure of compact refined equiaxed grains can be...Laser melting deposition with WC addition has been developed to fabricate high-strength CrMnFeCoNibased high-entropy alloys-based composites.By this technique,a microstructure of compact refined equiaxed grains can be achieved,and the tensile strength can be remarkably improved.The sample with 5 wt%WC addition shows a promising mechanical performance with a tensile strength of 800 MPa and an elongation of 37%.The improvement in mechanical property may be attributed to the formation of Cr(23)C6 reinforcement precipitates,which could promote the heterogeneous nucleation of grains and hinder the propagation of slip bands.展开更多
Research on two-dimensional(2D) materials has been explosively increasing in last seventeen years in varying subjects including condensed matter physics, electronic engineering, materials science, and chemistry since ...Research on two-dimensional(2D) materials has been explosively increasing in last seventeen years in varying subjects including condensed matter physics, electronic engineering, materials science, and chemistry since the mechanical exfoliation of graphene in 2004. Starting from graphene, 2D materials now have become a big family with numerous members and diverse categories. The unique structural features and physicochemical properties of 2D materials make them one class of the most appealing candidates for a wide range of potential applications. In particular, we have seen some major breakthroughs made in the field of 2D materials in last five years not only in developing novel synthetic methods and exploring new structures/properties but also in identifying innovative applications and pushing forward commercialisation. In this review, we provide a critical summary on the recent progress made in the field of 2D materials with a particular focus on last five years. After a brief backgroundintroduction, we first discuss the major synthetic methods for 2D materials, including the mechanical exfoliation, liquid exfoliation, vapor phase deposition, and wet-chemical synthesis as well as phase engineering of 2D materials belonging to the field of phase engineering of nanomaterials(PEN). We then introduce the superconducting/optical/magnetic properties and chirality of 2D materials along with newly emerging magic angle 2D superlattices. Following that, the promising applications of 2D materials in electronics, optoelectronics, catalysis, energy storage, solar cells, biomedicine, sensors, environments, etc. are described sequentially. Thereafter, we present the theoretic calculations and simulations of 2D materials. Finally, after concluding the current progress, we provide some personal discussions on the existing challenges and future outlooks in this rapidly developing field.展开更多
AIM: To compare the short-term outcomes of patients who underwent proximal gastrectomy with jejunal interposition (PGJI) with those undergoing total gastrectomy with Roux-en-Y anastomosis (TGRY).
A biomimetic underwater vehicle propelled by two undulating long-fins is introduced in this paper. The concerned vehicle is propelled by two symmetrical undulating long-fins installed on both sides. Ten servo motors a...A biomimetic underwater vehicle propelled by two undulating long-fins is introduced in this paper. The concerned vehicle is propelled by two symmetrical undulating long-fins installed on both sides. Ten servo motors are employed to drive the long-fins and cosine wave function is employed for motor control. A real-time control system is designed for controlling the long-fins by adjusting its oscillating frequency and oscillating amplitude. An inertial measurement unit is installed to collect the accelerations and angular velocity. To obtain the relationship between oscillating frequency/amplitude and swimming performance, kinematic analysis and hydromechanic analysis are given. By dividing the long-fin into many small elements and computing the hydrodynamic force acting on each element, the instantaneous thrust generated by the long-fin is obtained. Then the average thrust of the long-fin is obtained by summing up the forces acted on the elements in one undulating period. Then swimming experiments are carried out to validate the vehicle design and kinematic analysis and hydromechanic analysis. And two swimming motion modes including marching and rotating locomotion are chosen. Finally, discussions between the swimming performance and the oscillating parameters are given.展开更多
The Circular Electron Positron Collider(CEPC)is a large scientific project initiated and hosted by China,fostered through extensive collaboration with international partners.The complex comprises four accelerators:a 3...The Circular Electron Positron Collider(CEPC)is a large scientific project initiated and hosted by China,fostered through extensive collaboration with international partners.The complex comprises four accelerators:a 30 GeV Linac,a 1.1 GeV Damping Ring,a Booster capable of achieving energies up to 180 GeV,and a Collider operating at varying energy modes(Z,W,H,and tt).The Linac and Damping Ring are situated on the surface,while the subterranean Booster and Collider are housed in a 100 km circumference underground tunnel,strategically accommodating future expansion with provisions for a potential Super Proton Proton Collider(SPPC).The CEPC primarily serves as a Higgs factory.In its baseline design with synchrotron radiation(SR)power of 30 MW per beam,it can achieve a luminosity of 5×10^(34)cm^(-2)s^(-1)per interaction point(IP),resulting in an integrated luminosity of 13 ab^(-1)for two IPs over a decade,producing 2.6 million Higgs bosons.Increasing the SR power to 50 MW per beam expands the CEPC's capability to generate 4.3 million Higgs bosons,facilitating precise measurements of Higgs coupling at sub-percent levels,exceeding the precision expected from the HL-LHC by an order of magnitude.This Technical Design Report(TDR)follows the Preliminary Conceptual Design Report(Pre-CDR,2015)and the Conceptual Design Report(CDR,2018),comprehensively detailing the machine's layout,performance metrics,physical design and analysis,technical systems design,R&D and prototyping efforts,and associated civil engineering aspects.Additionally,it includes a cost estimate and a preliminary construction timeline,establishing a framework for forthcoming engineering design phase and site selection procedures.Construction is anticipated to begin around 2027-2028,pending government approval,with an estimated duration of 8 years.The commencement of experiments and data collection could potentially be initiated in the mid-2030s.展开更多
Background A generally accepted guideline （＂41 rules＂） published by the International Consensus Group for Hematology Review （ICGHR） can not be suitable for all the laboratories because the facility type, laborat...Background A generally accepted guideline （＂41 rules＂） published by the International Consensus Group for Hematology Review （ICGHR） can not be suitable for all the laboratories because the facility type, laboratory requirements, sample volume, review rate, turn around time, instrument model and characters etc. are quite different from each other, which may cause a higher workload for microscopy review or lead to false or misleading results. Therefore, we decided to develop the personalized review criteria for 4 series of hematology analyzers in the same hospital, and describe all the implement procedures in detail. Methods The total 1770 blood samples were collected from Peking Union Medical College Hospital. Referring to the suggested criteria by international consensus group for hematology review （＂41 rules＂）, the personalized review criteria for 4 series of hematology analyzers including Siemens Advia 2120, Sysmex XE-2100, Sysmex XT-1800i and Sysmex XS-800i were established and validated by adjusting the rules in order to reduce the false positive rate and keep the false negative acceptable by clinical. Results Using the ＂41 rules＂, high review rates of 37.94%, 35.56%, 33.44% and 37.94% were got respectively in Siemens Advia 2120, Sysmex XE-2100, Sysmex XT-1800i and Sysmex XS-800i. Three false positive rules mainly were observed in all of 4 analyzers： white blood cell 〈3×10^9/L or 〉30×10^9/L, platelet 〈100×10^9/L or 〉1000×10^9/L and immature granulocyte. Specialized rules were observed in different series of analyzers, atypicaVvariant lymphs flag were found mainly in Sysmex XE-2100, Aniso-RBC were found mainly in Sysmex XT-1800i, flag of ＂immature granulocyte＂ mainly in Sysmex XS-800i, Micro-RBC, Macro-RBC and Aniso-RBC mainly in Siemens Advia 2120. Rules of immature granulocyte blast, and NRBC flag would be mainly triggered by hematology malignant tumor. We could not delete these rules due to the risk of false negative of serious disease, other rules were deleted or r展开更多
基金supported by the National Science Foundation of China(61571117,61522106,61138001,61302018 and 61401089)Natural Science Foundation of the Jiangsu Province(BK2012019)the 111 Project(111-2-05).
文摘Metamaterials based on effective media can be used to produce a number of unusual physical properties(for example,negative refraction and invisibility cloaking)because they can be tailored with effective medium parameters that do not occur in nature.Recently,the use of coding metamaterials has been suggested for the control of electromagnetic waves through the design of coding sequences using digital elements‘0’and‘1,'which possess opposite phase responses.Here we propose the concept of an anisotropic coding metamaterial in which the coding behaviors in different directions are dependent on the polarization status of the electromagnetic waves.We experimentally demonstrate an ultrathin and flexible polarization-controlled anisotropic coding metasurface that functions in the terahertz regime using specially designed coding elements.By encoding the elements with elaborately designed coding sequences(both 1-bit and 2-bit sequences),the x-and y-polarized waves can be anomalously reflected or independently diffused in three dimensions.The simulated far-field scattering patterns and near-field distributions are presented to illustrate the dual-functional performance of the encoded metasurface,and the results are consistent with the measured results.We further demonstrate the ability of the anisotropic coding metasurfaces to generate a beam splitter and realize simultaneous anomalous reflections and polarization conversions,thus providing powerful control of differently polarized electromagnetic waves.The proposed method enables versatile beam behaviors under orthogonal polarizations using a single metasurface and has the potential for use in the development of interesting terahertz devices.
基金This work was supported by the National High Tech Projects(2012AA030402 and 2011AA010202)the National Science Foundation of China(61138001,61171024,61171026,61371035 and 11227904)+2 种基金the 111 Project(111-2-05)the Natural Science Foundation of Jiangsu Province(BK2012019)and the 973 Program(2014CB339800).
文摘The terahertz region is a special region of the electromagnetic spectrum that incorporates the advantages of both microwaves and infrared light waves.In the past decade,metamaterials with effective medium parameters or gradient phases have been studied to control terahertz waves and realize functional devices.Here,we present a new approach to manipulate terahertz waves by using coding metasurfaces that are composed of digital coding elements.We propose a general coding unit based on a Minkowski closed-loop particle that is capable of generating 1-bit coding(with two phase states of 0 and 180°),2-bit coding(with four phase states of 0,90°,180°,and 270°),and multi-bit coding elements in the terahertz frequencies by using different geometric scales.We show that multi-bit coding metasurfaces have strong abilities to control terahertz waves by designing-specific coding sequences.As an application,we demonstrate a new scattering strategy of terahertz waves—broadband and wide-angle diffusion—using a 2-bit coding metasurface with a special coding design and verify it by both numerical simulations and experiments.The presented method opens a new route to reducing the scattering of terahertz waves.
基金Supported by the National Science Foundation for Distinguished Young Scholars of China,No.81625016the National Natural Science Foundation of Shanghai,No.19ZR1410800+2 种基金the National Natural Science Foundation of China,No.81872366,No.81871941,No.81827807,No.81802675,and No.81702341the Outstanding Academic Leader Program of the “Technological Innovation Action Plan” of the Shanghai Science and Technology Commission,No.18XD1401200the Young Talented Specialist Training Program of Shanghai
文摘BACKGROUND Systemic inflammation and nutrition status play an important role in cancer metastasis.The combined index of hemoglobin,albumin,lymphocyte,and platelet(HALP),consisting of haemoglobin,albumin,lymphocytes,and platelets,is considered as a novel marker to reflect both systemic inflammation and nutrition status.However,no studies have investigated the relationship between HALP and survival of patients with pancreatic cancer following radical resection.AIM To evaluate the prognostic value of preoperative HALP in pancreatic cancer patients.METHODS The preoperative serum levels of hemoglobin,albumin,lymphocyte counts,and platelet counts were routinely detected in 582 pancreatic adenocarcinoma patients who underwent radical resection.The relationship between postoperative survival and the preoperative level of HALP was investigated.RESULTS Low levels of HALP were significantly associated with lymph node metastasis(P=0.002),poor tumor differentiation(P=0.032),high TNM stage(P=0.008),female patients(P=0.005)and tumor location in the head of the pancreas(P<0.001).Low levels of HALP were associated with early recurrence[7.3 mo vs 16.3 mo,P<0.001 for recurrence-free survival(RFS)]and short survival[11.5 mo vs 23.6 mo,P<0.001 for overall survival(OS)]in patients with resected pancreatic adenocarcinoma.A low level of HALP was an independent risk factor for early recurrence and short survival irrespective of sex and tumor location.CONCLUSION Low levels of HALP may be a significant risk factor for RFS and OS in patients with resected pancreatic cancer.
基金supported financially by the Project supported by CAEP Foundation (No.CX2019020)the Science and Technology Plan Project of Sichuan (No.2018G20146)the Special Fund Project of Panzhihua (No.2017CY-G-21)
文摘Laser melting deposition with WC addition has been developed to fabricate high-strength CrMnFeCoNibased high-entropy alloys-based composites.By this technique,a microstructure of compact refined equiaxed grains can be achieved,and the tensile strength can be remarkably improved.The sample with 5 wt%WC addition shows a promising mechanical performance with a tensile strength of 800 MPa and an elongation of 37%.The improvement in mechanical property may be attributed to the formation of Cr(23)C6 reinforcement precipitates,which could promote the heterogeneous nucleation of grains and hinder the propagation of slip bands.
文摘Research on two-dimensional(2D) materials has been explosively increasing in last seventeen years in varying subjects including condensed matter physics, electronic engineering, materials science, and chemistry since the mechanical exfoliation of graphene in 2004. Starting from graphene, 2D materials now have become a big family with numerous members and diverse categories. The unique structural features and physicochemical properties of 2D materials make them one class of the most appealing candidates for a wide range of potential applications. In particular, we have seen some major breakthroughs made in the field of 2D materials in last five years not only in developing novel synthetic methods and exploring new structures/properties but also in identifying innovative applications and pushing forward commercialisation. In this review, we provide a critical summary on the recent progress made in the field of 2D materials with a particular focus on last five years. After a brief backgroundintroduction, we first discuss the major synthetic methods for 2D materials, including the mechanical exfoliation, liquid exfoliation, vapor phase deposition, and wet-chemical synthesis as well as phase engineering of 2D materials belonging to the field of phase engineering of nanomaterials(PEN). We then introduce the superconducting/optical/magnetic properties and chirality of 2D materials along with newly emerging magic angle 2D superlattices. Following that, the promising applications of 2D materials in electronics, optoelectronics, catalysis, energy storage, solar cells, biomedicine, sensors, environments, etc. are described sequentially. Thereafter, we present the theoretic calculations and simulations of 2D materials. Finally, after concluding the current progress, we provide some personal discussions on the existing challenges and future outlooks in this rapidly developing field.
文摘AIM: To compare the short-term outcomes of patients who underwent proximal gastrectomy with jejunal interposition (PGJI) with those undergoing total gastrectomy with Roux-en-Y anastomosis (TGRY).
基金Supported by National Natural Science Foundation of China(51175496,61233014,61005075)National High Technology Research and Development Program of China(863 Program)(2012AA041402)
文摘A biomimetic underwater vehicle propelled by two undulating long-fins is introduced in this paper. The concerned vehicle is propelled by two symmetrical undulating long-fins installed on both sides. Ten servo motors are employed to drive the long-fins and cosine wave function is employed for motor control. A real-time control system is designed for controlling the long-fins by adjusting its oscillating frequency and oscillating amplitude. An inertial measurement unit is installed to collect the accelerations and angular velocity. To obtain the relationship between oscillating frequency/amplitude and swimming performance, kinematic analysis and hydromechanic analysis are given. By dividing the long-fin into many small elements and computing the hydrodynamic force acting on each element, the instantaneous thrust generated by the long-fin is obtained. Then the average thrust of the long-fin is obtained by summing up the forces acted on the elements in one undulating period. Then swimming experiments are carried out to validate the vehicle design and kinematic analysis and hydromechanic analysis. And two swimming motion modes including marching and rotating locomotion are chosen. Finally, discussions between the swimming performance and the oscillating parameters are given.
基金support from diverse funding sources,including the National Key Program for S&T Research and Development of the Ministry of Science and Technology(MOST),Yifang Wang's Science Studio of the Ten Thousand Talents Project,the CAS Key Foreign Cooperation Grant,the National Natural Science Foundation of China(NSFC)Beijing Municipal Science&Technology Commission,the CAS Focused Science Grant,the IHEP Innovation Grant,the CAS Lead Special Training Programthe CAS Center for Excellence in Particle Physics,the CAS International Partnership Program,and the CAS/SAFEA International Partnership Program for Creative Research Teams.
文摘The Circular Electron Positron Collider(CEPC)is a large scientific project initiated and hosted by China,fostered through extensive collaboration with international partners.The complex comprises four accelerators:a 30 GeV Linac,a 1.1 GeV Damping Ring,a Booster capable of achieving energies up to 180 GeV,and a Collider operating at varying energy modes(Z,W,H,and tt).The Linac and Damping Ring are situated on the surface,while the subterranean Booster and Collider are housed in a 100 km circumference underground tunnel,strategically accommodating future expansion with provisions for a potential Super Proton Proton Collider(SPPC).The CEPC primarily serves as a Higgs factory.In its baseline design with synchrotron radiation(SR)power of 30 MW per beam,it can achieve a luminosity of 5×10^(34)cm^(-2)s^(-1)per interaction point(IP),resulting in an integrated luminosity of 13 ab^(-1)for two IPs over a decade,producing 2.6 million Higgs bosons.Increasing the SR power to 50 MW per beam expands the CEPC's capability to generate 4.3 million Higgs bosons,facilitating precise measurements of Higgs coupling at sub-percent levels,exceeding the precision expected from the HL-LHC by an order of magnitude.This Technical Design Report(TDR)follows the Preliminary Conceptual Design Report(Pre-CDR,2015)and the Conceptual Design Report(CDR,2018),comprehensively detailing the machine's layout,performance metrics,physical design and analysis,technical systems design,R&D and prototyping efforts,and associated civil engineering aspects.Additionally,it includes a cost estimate and a preliminary construction timeline,establishing a framework for forthcoming engineering design phase and site selection procedures.Construction is anticipated to begin around 2027-2028,pending government approval,with an estimated duration of 8 years.The commencement of experiments and data collection could potentially be initiated in the mid-2030s.
文摘Background A generally accepted guideline （＂41 rules＂） published by the International Consensus Group for Hematology Review （ICGHR） can not be suitable for all the laboratories because the facility type, laboratory requirements, sample volume, review rate, turn around time, instrument model and characters etc. are quite different from each other, which may cause a higher workload for microscopy review or lead to false or misleading results. Therefore, we decided to develop the personalized review criteria for 4 series of hematology analyzers in the same hospital, and describe all the implement procedures in detail. Methods The total 1770 blood samples were collected from Peking Union Medical College Hospital. Referring to the suggested criteria by international consensus group for hematology review （＂41 rules＂）, the personalized review criteria for 4 series of hematology analyzers including Siemens Advia 2120, Sysmex XE-2100, Sysmex XT-1800i and Sysmex XS-800i were established and validated by adjusting the rules in order to reduce the false positive rate and keep the false negative acceptable by clinical. Results Using the ＂41 rules＂, high review rates of 37.94%, 35.56%, 33.44% and 37.94% were got respectively in Siemens Advia 2120, Sysmex XE-2100, Sysmex XT-1800i and Sysmex XS-800i. Three false positive rules mainly were observed in all of 4 analyzers： white blood cell 〈3×10^9/L or 〉30×10^9/L, platelet 〈100×10^9/L or 〉1000×10^9/L and immature granulocyte. Specialized rules were observed in different series of analyzers, atypicaVvariant lymphs flag were found mainly in Sysmex XE-2100, Aniso-RBC were found mainly in Sysmex XT-1800i, flag of ＂immature granulocyte＂ mainly in Sysmex XS-800i, Micro-RBC, Macro-RBC and Aniso-RBC mainly in Siemens Advia 2120. Rules of immature granulocyte blast, and NRBC flag would be mainly triggered by hematology malignant tumor. We could not delete these rules due to the risk of false negative of serious disease, other rules were deleted or r
