A facile one-step method was developed for the fabrication of hierarchical ZnO film on substrate. Neither seed nor catalyst layer is necessary for the growth of hierarchical ZnO film. Three kinds of nucleation process...A facile one-step method was developed for the fabrication of hierarchical ZnO film on substrate. Neither seed nor catalyst layer is necessary for the growth of hierarchical ZnO film. Three kinds of nucleation process were found, and the influences of growth time, growth electrolyte, growth temperature on the morphology of ZnO film were evaluated. Hierarchical ZnO film can absorb more than 97% of incident photons with wavelength shorter than 380 nm. Such hierarchical ZnO film would be a promising scaffold for photoelectrochemical application.展开更多
Accelerating the development of agricultural cold chain logistics is of great significance to improve the competitiveness of agricultural products,increase rural incomes and ensure food security. The present situation...Accelerating the development of agricultural cold chain logistics is of great significance to improve the competitiveness of agricultural products,increase rural incomes and ensure food security. The present situation and main problems of agricultural cold chain logistics in Heilongjiang Province were analyzed from five aspects,such as the scale of construction,infrastructure,status quo of cold chain logistics technology,cold chain logistics enterprises and development environment,and proposed that Heilongjiang Province should focus on the development of poultry,fruit and vegetable,aquatic products,and processed food cold chain,then the strategic implementation measures for above areas were put forward.展开更多
Molybdenum phosphide (MoP) flakes were synthesized by the reduction of hexaammonium heptamolybdate tetrahydrate and ammonium dihydrogen phosphate. The flakes are porous and constructed by MoP nanoparticles with ca. 10...Molybdenum phosphide (MoP) flakes were synthesized by the reduction of hexaammonium heptamolybdate tetrahydrate and ammonium dihydrogen phosphate. The flakes are porous and constructed by MoP nanoparticles with ca. 100 nm diameters. The lateral size of flakes ranges from less than 1 μm to larger than 5 μm, and the thickness of MoP fakes is ca. 200 nm. The mixture of MoP flakes and carbon black exhibits effective catalytic activity in the hydrogen evolution reaction. The optimal overpotential required for 20 mA·cm﹣2 current density is 155 mV in acidic solution and 184 mV in basic solution. The mixture can work stably in long-term hydrogen generation in both acidic and basic solution. The faradaic yield of mixture in hydrogen evolution reaction is nearly 100% in both acidic and basic solution. The Mo and P species in MoP flakes are found to have small positive and negative charge, respectively. The catalytic activity of MoP flakes is likely to be correlated with this charged nature.展开更多
Conventional mechanical machining of a composite material comprising an aluminum matrix reinforced with a high volume fraction of SiC particles(hereinafter referred to as an SiCp/Al composite)faces problems such as ra...Conventional mechanical machining of a composite material comprising an aluminum matrix reinforced with a high volume fraction of SiC particles(hereinafter referred to as an SiCp/Al composite)faces problems such as rapid tool wear,high specific cutting force,and poor surface integrity.Instead,a promising method for solving these problems is laser-induced oxidation-assisted milling(LOAM):under laser irradiation,the local workpiece material reacts with oxygen,thus forming loose and porous oxides that are easily removed.In the present work,the oxidation mechanism of SiCp/Al irradiated by a nanosecond pulsed laser is studied to better understand the laser-induced oxidation behavior and control the characteristics of the oxides,with laser irradiation experiments performed on a 65%SiCp/Al composite with various laser parameters and auxiliary gases(oxygen,nitrogen,and argon).With increasing laser pulse energy density,both the ablated groove depth and the width of the heat-affected zone increase.When oxygen is used as the auxiliary gas,an oxide layer composed of SiO_(2)and Al2O3 forms,and CO_(2)is produced and escapes from the material,thereby forming pores in the oxides.However,when nitrogen or argon is used as the auxiliary gas,a recast layer is produced that is relatively difficult to remove.Under laser irradiation,the sputtered material reacts with oxygen to form oxides on both sides of the ablated groove,and as the laser scanning path advances,the produced oxides accumulate to form an oxide layer.LOAM and conventional milling are compared using the same milling parameters,and LOAM is found to be better for reduced milling force and tool wear and improved machined surface quality.展开更多
We investigate the single-pulse emission variations of two pulsars,PSRs J0211+4235 and J0553+4111,observed with the Five-hundred-meter Aperture Spherical radio Telescope at the 1.25 GHz central frequency.The observati...We investigate the single-pulse emission variations of two pulsars,PSRs J0211+4235 and J0553+4111,observed with the Five-hundred-meter Aperture Spherical radio Telescope at the 1.25 GHz central frequency.The observation sessions span from 2020 December to 2021 July,with 21 and 22 observations for them respectively.The integrated pulse profile of PSR J0211+4235 shows that there is a weak pulse component following the main component,and PSR J0553+4111 displays a bimodal profile with a bridge component in the middle.PSR J0211+4235 presents significant nulling phenomenon with nulling duration lasting from 2 to 115 pulses and burst duration lasting from 2 to 113 pulses.The NF of each observation is determined to be 45%-55%.No emission greater than threeσis found in the mean integrated profile of all nulling pulses.In most cases,the pulse energy changes abruptly during the transition from null to burst,while in the transition from burst to null there are two trends:abrupt and gradual.We find that the nulling phenomenon of PSR J0211+4235 is periodic by the Fourier transform of the null and burst state.In addition,the single-pulse modulation characteristics of these two pulsars are investigated,and the distributions of modulation index,LRFS and 2DFS are analyzed with PSRSALSA.The left peak of PSR J0553+4111 has intensity modulation.Finally,the polarization properties of these two pulsars are obtained through polarization calibration,and their characteristics are analyzed.The possible physical mechanisms of these phenomena are discussed.展开更多
Using principle and method of the system dynamics,this paper takes a qualitative analysis on the inventory of supply chain of supermarket-oriented agricultural products,and compares with the supply chain of wholesale-...Using principle and method of the system dynamics,this paper takes a qualitative analysis on the inventory of supply chain of supermarket-oriented agricultural products,and compares with the supply chain of wholesale-oriented agricultural products. Two inventory models are established for these two different modes of supply chain. Through simulation of two models in the case of random demand and quantitative analysis of results,it is found that the inventory of supply chain of supermarket-oriented agricultural products has smaller fluctuation than that of wholesaler-oriented agricultural products. Besides,both the inventory level and bullwhip effect of above chain are lowered.展开更多
Molecular marker techniques have been widely applied in the fields of genetic diversity analysis,germplasm resources identification,molecular fingerprint and genetic linkage map construction,QTL mapping and molecular ...Molecular marker techniques have been widely applied in the fields of genetic diversity analysis,germplasm resources identification,molecular fingerprint and genetic linkage map construction,QTL mapping and molecular assisted breeding.On the basis of stating the concept of molecular marker techniques based on single primer amplification reactions,this study focused on the sorting and induction of single-primer molecular marker techniques,and expounded their derivative development.Finally,the application prospect and future expectation of single-primer molecular marker techniques were described in detail.The purpose of this study was to clarify the types of molecular marker techniques based on single primer amplification reactions,so that researchers can quickly and conveniently select molecular marker techniques according to their own specific scientific research conditions.展开更多
[Objectives]To establish a non-toxic and efficient method for extracting DNA and total RNA from peanuts and laying a solid foundation for the molecular biology study of peanuts.[Methods]Based on the principle and meth...[Objectives]To establish a non-toxic and efficient method for extracting DNA and total RNA from peanuts and laying a solid foundation for the molecular biology study of peanuts.[Methods]Based on the principle and method of purifying nucleic acids by silica gel adsorption at high salt and low pH condition,a non-toxic and efficient method to extract peanut DNA and total RNA using cetyltrimethyl ammonium bromide(CTAB)extraction solution was designed.The quality and purity of nucleic acids were detected by agarose gel electrophoresis and nucleic acids protein analyzer,respectively.The quality of DNA was further verified by enzyme digestion and PCR amplification using molecular marker techniques.The quality of total RNA was further verified by reverse transcription(RT)-PCR of actin gene and cDNA-SCoT gene differential display technique.[Results]The agarose gel electrophoresis test showed that the peanut DNA extracted by a low-toxic and effective method is free of contamination and degradation.Through the detection by the nucleic acid protein analyzer,the DNA concentration,yield,A260/A280 and A260/A230 of 5 peanut varieties were 419.6-498.2 ng/μL,20.98-24.91μg/g,1.89-1.96 and 2.03-2.28,respectively.The DNA was of high quality and can be completely digested by EcoRI restriction enzymes,and also can be used for SCoT and SRAP molecular marker technology analysis.The RNA extracted from different tissues of peanuts showed no visible DNA bands by non-denaturing agarose gel electrophoresis.The separated 28S bands were brighter than 18S.The ratio of A260/A280 and A260/A230 showed that the RNA quality was good and can be used for reverse transcription,RT-PCR of actin gene and amplification of cDNA-SCoT gene differential display technique.[Conclusions]This experiment established a low-toxic and effective method for extracting DNA and total RNA from peanuts.Compared with traditional methods,this method is more time-saving and cheaper than commercial kits.The most important point is that this method does not use toxic reagents such as phenol,chloroform and isopropanol.Thus,it is expected to be widely applied in molecular biology research.展开更多
The herbal textual research of Inulae Flos was carried out from the aspects of name,origin,habit and distribution,nature and flavor,meridian,efficacy and indications by referring to ancient Chinese herbal books and di...The herbal textual research of Inulae Flos was carried out from the aspects of name,origin,habit and distribution,nature and flavor,meridian,efficacy and indications by referring to ancient Chinese herbal books and different editions of Pharmacopoeia of People’s Republic of China.After textual research,Inulae Flos has been named as"Inulae Flos"since Shennong Bencaojing(Shennong’s Herbal Classic).Its original plant is Inula japonica Thunb.or I.britannica L.,which is easy to multiply and widely distributed.Inulae Flos is used medically with clean and dry capitulum,and there is also honey-burning method.The description of Inulae Flos in Pharmacopoeia of People’s Republic of China,such as nature and flavor,meridian,efficacy and indications,is generally consistent with the records in traditional herbal books.展开更多
Cobalt sulfide (Co<sub>9</sub>S<sub>8</sub>) nanotubes were found to be an electrocatalyst for the hydrogen evolution reaction under alkaline condition. An electrode comprising of Co<sub>...Cobalt sulfide (Co<sub>9</sub>S<sub>8</sub>) nanotubes were found to be an electrocatalyst for the hydrogen evolution reaction under alkaline condition. An electrode comprising of Co<sub>9</sub>S<sub>8</sub> nanotubes on a glass carbon electrode (GCE) (mass loading: 0.855 mg·cm<sup>-2</sup>) produced a cathodic current density of 20 mA·cm<sup>-2</sup> at an overpotential of 320 mV. The Co<sub>9</sub>S<sub>8</sub>/GCE electrode was stable over 20,000 s during potentiostatic electrolysis. Minor degradation of reduction current after 4000 cyclic voltammetric sweeps suggests the long-term viability under operating conditions. The faradaic efficiency of Co<sub>9</sub>S<sub>8</sub> nanotubes is nearly 100% during the electrolysis of water.展开更多
The lightweight design of hydraulic quadruped robots,especially the lightweight design of the leg joint Hydraulic Drive Unit(HDU),can improve the robot's response speed,motion speed,endurance,and load capacity.How...The lightweight design of hydraulic quadruped robots,especially the lightweight design of the leg joint Hydraulic Drive Unit(HDU),can improve the robot's response speed,motion speed,endurance,and load capacity.However,the lightweight design of HDU is a huge challenge due to the need for structural strength.This paper is inspired by the geometric shape of fish bones and biomimetic reinforcing ribs on the surface of the HDU shell are designed to increase its strength and reduce its weight.First,a HDU shell with biomimetic fish bone reinforcing ribs structure is proposed.Then,the MATLAB toolbox and ANSYS finite element analysis module are used to optimize the parameters of the biomimetic reinforcing ribs structure and the overall layout of the shell.Finally,the HDU shell is manufactured using additive manufacturing technology,and a performance testing platform is built to conduct dynamic and static performance tests on the designed HDU.The experimental results show that the HDU with biomimetic fish bone reinforcing ribs has excellent dynamic performance and better static performance than the prototype model,and the weight of the shell is reduced by 20%compared to the prototype model.This work has broad application prospects in the lightweight and high-strength design of closed-pressure vessel components.展开更多
Axially coordinated metal-porphyrin-functionalized multi-walled carbon nanotube (MWCNT) nanohybrids were prepared via two different synthetic approaches (a one-pot 1,3-dipolar cycloaddition reaction and a stepwise ...Axially coordinated metal-porphyrin-functionalized multi-walled carbon nanotube (MWCNT) nanohybrids were prepared via two different synthetic approaches (a one-pot 1,3-dipolar cycloaddition reaction and a stepwise approach that involved 1,3-dipolar cycloaddition followed by nucleophilic substitution), and characterized through spectroscopic techniques. Attachment of the tin porphyrins to the surface of the MWCNTs significantly improves their solubility and ease of processing. These axially coordinated (5,10,15,20-tetraphenylporphyrinato)tin(Ⅳ) (SnTPP)- MWCNTs exhibit significant fluorescence quenching. The third-order nonlinear optical properties of the resultant nanohybrids were studied by using the Z-scan technique at 532 nm with both nanosecond and picosecond laser pulses. The results show that the nanohybrids exhibit significant reverse saturable absorption or saturable absorption when nanosecond or picosecond pulses, respectively, are employed. Improvement in the nanosecond regime nonlinear absorption is observed on proceeding to the nanohybrids and is ascribed to a combination of the outstanding properties of MWCNTs and the chemically attached metal-porphyrins.展开更多
Stent placement is an effective palliation therapy for malignant colorectal obstruction.However,recurrent obstruction is a common severe complication caused by tumor ingrowth into the stent lumen.Conventional covered ...Stent placement is an effective palliation therapy for malignant colorectal obstruction.However,recurrent obstruction is a common severe complication caused by tumor ingrowth into the stent lumen.Conventional covered stents play a part in preventing the tumor from growing inward but at the expense of significantly increasing the risk of stent migration.Therefore,there is an urgent demand to develop stents with sustained antitumor and antimigration abilities.Herein,we propose a facile method for fabricating multifunctional bioinspired colorectal stents using 3D printing technology.Inspired by high-adhesion biological structures(gecko feet,tree frog toe pads,and octopus suckers)in nature,different types of bioinspired colorectal stents are designed to reduce migration.After functionalization with graphene oxide(GO),bioinspired colorectal stents show excellent and controllable photothermal performance,which is validated by effective ablation of colon cancer cells in vitro and tumors in vivo.Besides,the bioinspired colorectal stents demonstrate the feasibility of transanal placement and opening of the obstructed colon.More importantly,the facile manufacturing process of multifunctional bioinspired colorectal stents is appealing for mass production,Hence,the developed multifunctional bioinspired colorectal stents exhibit a highly promising potential in clinical applications.展开更多
Electron-donating porphyrins(Por),electron-accepting phthalocyanines(Pcs),and reduced graphene oxide(RGO)were integrated into a multicomponent nanoconjugate(Por-RGO-Pc).The donor-π-acceptor nanoconjugate Por-RGO-Pc w...Electron-donating porphyrins(Por),electron-accepting phthalocyanines(Pcs),and reduced graphene oxide(RGO)were integrated into a multicomponent nanoconjugate(Por-RGO-Pc).The donor-π-acceptor nanoconjugate Por-RGO-Pc was characterized using Fourier transform infrared spectroscopy(FTIR),transmission electron microscopy(TEM),scanning electron microscopy(SEM),atomic force microscopy(AFM),and ultraviolet-visible(UV-Vis)spectroscopy.Photoinduced cascading electron/charge transfer from Por to RGO and from RGO to Pc was established from fluorescence,electrochemical,and femtosecond transient absorption(fs-TA)spectroscopy studies.The increased distance between the electron donors and acceptors of the Por-RGO-Pc nanoconjugate compared to the parent materials and the intermediate RGO-Pc results in longlived charge separation,and an enhancement in nonlinear optical(NLO)absorption(a large NLO coefficient of about 827.44 cm/GW)towards nanosecond laser irradiation at 532 nm.展开更多
Edge-functionalization of graphene is emerging as a powerful chemical method for the construction ofπ-delocalized highlyplanar graphene nanoconjugates that are not accessible through surface-supported syntheses.Herei...Edge-functionalization of graphene is emerging as a powerful chemical method for the construction ofπ-delocalized highlyplanar graphene nanoconjugates that are not accessible through surface-supported syntheses.Herein,a graphene-porphyrin nanoconjugate via a robust pyrazine(pz)linkage has been obtained by condensing 2,3-diamino-5,10,15,20-tetraphenylporphyrin(DA-TPP)with ortho-quinone(o-quinone)moieties at edge sites of graphene oxide(GO).The as-prepared GO-pz-TPP exhibits an intense absorption extending from 375 to 900 nm and a high quenching yield(98%)of fluorescence,indicating a strong electronic coupling effect between GO and TPP units.GO-pz-TPP displays strong nonlinear optical(NLO)absorption and giant NLO coefficients with 800 and 1,030 nm fs laser,in sharp contrast to traditional graphene-porphyrin nanohybrids only NLO-active towards ns laser.Such a dramatic NLO performance towards femtosecond pulsed laser has not been achieved in any carbonchromophores nanohybridized materials to date.This work validates theπ-extended edge-functionalization strategy as a means to tune the NLO properties of graphene,thereby providing a new paradigm for the assembly of versatile optoelectronic materials.展开更多
Functional materials displaying large ultrafast third-order optical nonlinearities across a wide spectral region and broad temporal domain are required for all-optical signal processing.Particularly desirable is nonli...Functional materials displaying large ultrafast third-order optical nonlinearities across a wide spectral region and broad temporal domain are required for all-optical signal processing.Particularly desirable is nonlinear optical(NLO)activity at near-infrared(NIR)wavelengths with femtosecond pulses.Herein the first triply-fused porphyrin dimer(TFP)-functionalized single-walled carbon nanotube(SWCNT)nanohybrid was successfully constructed by covalently grafting TFPs onto SWCNT.The results of Z-scan techniques demonstrate that the newly obtained TFP-SWCNT nanohybrid was found with a strong NLO performance under both nanosecond and femtosecond irradiation.In the nanosecond regime,an enhancement in optical limiting(OL)of the TFP-SWCNT nanohybrid is seen at 532 nm when compared with the performance of porphyrin monomer-functionalized SWCNT nanohybrid Por-SWCNT.Under femtosecond irradiation,the TFP-SWCNT nanohybrid exhibits a particularly strong OL effect with a giant two-photon absorption(TPA)cross section value(ca.15,500 GM)at 800 nm pulses that mainly stems from intense TPA of TFP,in sharp contrast to the Por-SWCNT nanohybrid which exhibits only saturable absorption under identical irradiation.These results demonstrate that the newly-developed TFP-SWCNT nanohybrid is a very promising OL candidate for practical applications across wide spectral and temporal domains,and that covalently functionalizing carbon-based materials with triply-fused chromophores may be a useful approach to engineering adaptable photonic devices with broad-ranging NLO activity.展开更多
文摘A facile one-step method was developed for the fabrication of hierarchical ZnO film on substrate. Neither seed nor catalyst layer is necessary for the growth of hierarchical ZnO film. Three kinds of nucleation process were found, and the influences of growth time, growth electrolyte, growth temperature on the morphology of ZnO film were evaluated. Hierarchical ZnO film can absorb more than 97% of incident photons with wavelength shorter than 380 nm. Such hierarchical ZnO film would be a promising scaffold for photoelectrochemical application.
基金国家重点研发计划-中国和意大利政府间合作项目(2018YFE0118100)国家自然科学基金(22025206,21721004,21991090,22002159,22088102,21833009)+4 种基金辽宁省“兴辽英才计划”项目(XLYC2002012,XLYC1802126)中国科学院洁净能源创新研究院-榆林学院联合基金(YLU-DNL Fund 2021019)中国科学院科研仪器设备研制项目(YJKYYQ20190003)大连市科技创新基金(2019J12GX031)大连化物所创新研究基金(DICP I202009).
基金Supported by the Soft Science Project of Science and Technology Program of Heilongjiang Province in 2012 (GC12D112)Humanities and Social Science Program of Department of Education of Heilongjiang Province in 2013 (12532075)Humanities and Social Science Foundation of the Ministry of Education (10YJA630070)
文摘Accelerating the development of agricultural cold chain logistics is of great significance to improve the competitiveness of agricultural products,increase rural incomes and ensure food security. The present situation and main problems of agricultural cold chain logistics in Heilongjiang Province were analyzed from five aspects,such as the scale of construction,infrastructure,status quo of cold chain logistics technology,cold chain logistics enterprises and development environment,and proposed that Heilongjiang Province should focus on the development of poultry,fruit and vegetable,aquatic products,and processed food cold chain,then the strategic implementation measures for above areas were put forward.
文摘Molybdenum phosphide (MoP) flakes were synthesized by the reduction of hexaammonium heptamolybdate tetrahydrate and ammonium dihydrogen phosphate. The flakes are porous and constructed by MoP nanoparticles with ca. 100 nm diameters. The lateral size of flakes ranges from less than 1 μm to larger than 5 μm, and the thickness of MoP fakes is ca. 200 nm. The mixture of MoP flakes and carbon black exhibits effective catalytic activity in the hydrogen evolution reaction. The optimal overpotential required for 20 mA·cm﹣2 current density is 155 mV in acidic solution and 184 mV in basic solution. The mixture can work stably in long-term hydrogen generation in both acidic and basic solution. The faradaic yield of mixture in hydrogen evolution reaction is nearly 100% in both acidic and basic solution. The Mo and P species in MoP flakes are found to have small positive and negative charge, respectively. The catalytic activity of MoP flakes is likely to be correlated with this charged nature.
基金supported by the Fundamental Research Funds for the Central Universities(Grant No.NT2021020)。
文摘Conventional mechanical machining of a composite material comprising an aluminum matrix reinforced with a high volume fraction of SiC particles(hereinafter referred to as an SiCp/Al composite)faces problems such as rapid tool wear,high specific cutting force,and poor surface integrity.Instead,a promising method for solving these problems is laser-induced oxidation-assisted milling(LOAM):under laser irradiation,the local workpiece material reacts with oxygen,thus forming loose and porous oxides that are easily removed.In the present work,the oxidation mechanism of SiCp/Al irradiated by a nanosecond pulsed laser is studied to better understand the laser-induced oxidation behavior and control the characteristics of the oxides,with laser irradiation experiments performed on a 65%SiCp/Al composite with various laser parameters and auxiliary gases(oxygen,nitrogen,and argon).With increasing laser pulse energy density,both the ablated groove depth and the width of the heat-affected zone increase.When oxygen is used as the auxiliary gas,an oxide layer composed of SiO_(2)and Al2O3 forms,and CO_(2)is produced and escapes from the material,thereby forming pores in the oxides.However,when nitrogen or argon is used as the auxiliary gas,a recast layer is produced that is relatively difficult to remove.Under laser irradiation,the sputtered material reacts with oxygen to form oxides on both sides of the ablated groove,and as the laser scanning path advances,the produced oxides accumulate to form an oxide layer.LOAM and conventional milling are compared using the same milling parameters,and LOAM is found to be better for reduced milling force and tool wear and improved machined surface quality.
基金supported by National Key Research and Development Program of China(2022YFC2205203)the Major Science and Technology Program of Xinjiang Uygur Autonomous Region(No.2022A03013-1)+3 种基金the National Natural Science Foundation of China(NSFC,Grant Nos.U1838109,12041304)supported by the 2021 project Xinjiang Uygur autonomous region of China for Tianshan elitesthe Youth Innovation Promotion Association of CAS under No.2023069support from the Natural Science Foundation of Shanghai(Grant No.20ZR1467600)。
文摘We investigate the single-pulse emission variations of two pulsars,PSRs J0211+4235 and J0553+4111,observed with the Five-hundred-meter Aperture Spherical radio Telescope at the 1.25 GHz central frequency.The observation sessions span from 2020 December to 2021 July,with 21 and 22 observations for them respectively.The integrated pulse profile of PSR J0211+4235 shows that there is a weak pulse component following the main component,and PSR J0553+4111 displays a bimodal profile with a bridge component in the middle.PSR J0211+4235 presents significant nulling phenomenon with nulling duration lasting from 2 to 115 pulses and burst duration lasting from 2 to 113 pulses.The NF of each observation is determined to be 45%-55%.No emission greater than threeσis found in the mean integrated profile of all nulling pulses.In most cases,the pulse energy changes abruptly during the transition from null to burst,while in the transition from burst to null there are two trends:abrupt and gradual.We find that the nulling phenomenon of PSR J0211+4235 is periodic by the Fourier transform of the null and burst state.In addition,the single-pulse modulation characteristics of these two pulsars are investigated,and the distributions of modulation index,LRFS and 2DFS are analyzed with PSRSALSA.The left peak of PSR J0553+4111 has intensity modulation.Finally,the polarization properties of these two pulsars are obtained through polarization calibration,and their characteristics are analyzed.The possible physical mechanisms of these phenomena are discussed.
基金Supported by 2010 Humanities and Social Science Research Fund of Ministry of Education (10YJA630070)
文摘Using principle and method of the system dynamics,this paper takes a qualitative analysis on the inventory of supply chain of supermarket-oriented agricultural products,and compares with the supply chain of wholesale-oriented agricultural products. Two inventory models are established for these two different modes of supply chain. Through simulation of two models in the case of random demand and quantitative analysis of results,it is found that the inventory of supply chain of supermarket-oriented agricultural products has smaller fluctuation than that of wholesaler-oriented agricultural products. Besides,both the inventory level and bullwhip effect of above chain are lowered.
基金the National Natural Science Foundation of China(31960409,31960416)Guangxi Natural Science Foundation Program(2018GXNSFDA281027,2018GXNSFDA294004,2020GXNSFAA297081)Guangxi Academy of Agricultural Sciences Fund Project(GNK2017JZ13,GNK2018YM06,GNK31960409).
文摘Molecular marker techniques have been widely applied in the fields of genetic diversity analysis,germplasm resources identification,molecular fingerprint and genetic linkage map construction,QTL mapping and molecular assisted breeding.On the basis of stating the concept of molecular marker techniques based on single primer amplification reactions,this study focused on the sorting and induction of single-primer molecular marker techniques,and expounded their derivative development.Finally,the application prospect and future expectation of single-primer molecular marker techniques were described in detail.The purpose of this study was to clarify the types of molecular marker techniques based on single primer amplification reactions,so that researchers can quickly and conveniently select molecular marker techniques according to their own specific scientific research conditions.
基金Projects of National Natural Science Foundation of China(3166042831960409+2 种基金31960416)Projects of Guangxi Natural Science Foundation of China(2018GXNSFDA281027,2018GXNSFDA294004,2017GXNSFAA198032)Science and Technology Development Fund Project of Guangxi Academy of Agricultural Sciences(Gui Nong Ke 2018YM06,Gui Nong Ke 2017JZ13,31960409,Gui Nong Ke 2018YT12).
文摘[Objectives]To establish a non-toxic and efficient method for extracting DNA and total RNA from peanuts and laying a solid foundation for the molecular biology study of peanuts.[Methods]Based on the principle and method of purifying nucleic acids by silica gel adsorption at high salt and low pH condition,a non-toxic and efficient method to extract peanut DNA and total RNA using cetyltrimethyl ammonium bromide(CTAB)extraction solution was designed.The quality and purity of nucleic acids were detected by agarose gel electrophoresis and nucleic acids protein analyzer,respectively.The quality of DNA was further verified by enzyme digestion and PCR amplification using molecular marker techniques.The quality of total RNA was further verified by reverse transcription(RT)-PCR of actin gene and cDNA-SCoT gene differential display technique.[Results]The agarose gel electrophoresis test showed that the peanut DNA extracted by a low-toxic and effective method is free of contamination and degradation.Through the detection by the nucleic acid protein analyzer,the DNA concentration,yield,A260/A280 and A260/A230 of 5 peanut varieties were 419.6-498.2 ng/μL,20.98-24.91μg/g,1.89-1.96 and 2.03-2.28,respectively.The DNA was of high quality and can be completely digested by EcoRI restriction enzymes,and also can be used for SCoT and SRAP molecular marker technology analysis.The RNA extracted from different tissues of peanuts showed no visible DNA bands by non-denaturing agarose gel electrophoresis.The separated 28S bands were brighter than 18S.The ratio of A260/A280 and A260/A230 showed that the RNA quality was good and can be used for reverse transcription,RT-PCR of actin gene and amplification of cDNA-SCoT gene differential display technique.[Conclusions]This experiment established a low-toxic and effective method for extracting DNA and total RNA from peanuts.Compared with traditional methods,this method is more time-saving and cheaper than commercial kits.The most important point is that this method does not use toxic reagents such as phenol,chloroform and isopropanol.Thus,it is expected to be widely applied in molecular biology research.
文摘The herbal textual research of Inulae Flos was carried out from the aspects of name,origin,habit and distribution,nature and flavor,meridian,efficacy and indications by referring to ancient Chinese herbal books and different editions of Pharmacopoeia of People’s Republic of China.After textual research,Inulae Flos has been named as"Inulae Flos"since Shennong Bencaojing(Shennong’s Herbal Classic).Its original plant is Inula japonica Thunb.or I.britannica L.,which is easy to multiply and widely distributed.Inulae Flos is used medically with clean and dry capitulum,and there is also honey-burning method.The description of Inulae Flos in Pharmacopoeia of People’s Republic of China,such as nature and flavor,meridian,efficacy and indications,is generally consistent with the records in traditional herbal books.
文摘Cobalt sulfide (Co<sub>9</sub>S<sub>8</sub>) nanotubes were found to be an electrocatalyst for the hydrogen evolution reaction under alkaline condition. An electrode comprising of Co<sub>9</sub>S<sub>8</sub> nanotubes on a glass carbon electrode (GCE) (mass loading: 0.855 mg·cm<sup>-2</sup>) produced a cathodic current density of 20 mA·cm<sup>-2</sup> at an overpotential of 320 mV. The Co<sub>9</sub>S<sub>8</sub>/GCE electrode was stable over 20,000 s during potentiostatic electrolysis. Minor degradation of reduction current after 4000 cyclic voltammetric sweeps suggests the long-term viability under operating conditions. The faradaic efficiency of Co<sub>9</sub>S<sub>8</sub> nanotubes is nearly 100% during the electrolysis of water.
文摘The lightweight design of hydraulic quadruped robots,especially the lightweight design of the leg joint Hydraulic Drive Unit(HDU),can improve the robot's response speed,motion speed,endurance,and load capacity.However,the lightweight design of HDU is a huge challenge due to the need for structural strength.This paper is inspired by the geometric shape of fish bones and biomimetic reinforcing ribs on the surface of the HDU shell are designed to increase its strength and reduce its weight.First,a HDU shell with biomimetic fish bone reinforcing ribs structure is proposed.Then,the MATLAB toolbox and ANSYS finite element analysis module are used to optimize the parameters of the biomimetic reinforcing ribs structure and the overall layout of the shell.Finally,the HDU shell is manufactured using additive manufacturing technology,and a performance testing platform is built to conduct dynamic and static performance tests on the designed HDU.The experimental results show that the HDU with biomimetic fish bone reinforcing ribs has excellent dynamic performance and better static performance than the prototype model,and the weight of the shell is reduced by 20%compared to the prototype model.This work has broad application prospects in the lightweight and high-strength design of closed-pressure vessel components.
基金Financial support from the National Natural Science Foundation of China (Nos. 51432006, 50925207, and 51172100), the Ministry of Science and Technology of China for the International Science Linkages Program (No. 2011DFG52970), the Ministry of Education of China for the Changjiang Innovation Research Team (No. IRT14R23), the Ministry of Education and the State Administration of Foreign Experts Affairs for the 111 Project (No. B13025), 100 Talents Program of CAS, and Jiangsu Innovation Research Team are gratefully acknowledged. M. G. H., M. P. C., and C. Z. thank the Australian Research Council (ARC) for support.
文摘Axially coordinated metal-porphyrin-functionalized multi-walled carbon nanotube (MWCNT) nanohybrids were prepared via two different synthetic approaches (a one-pot 1,3-dipolar cycloaddition reaction and a stepwise approach that involved 1,3-dipolar cycloaddition followed by nucleophilic substitution), and characterized through spectroscopic techniques. Attachment of the tin porphyrins to the surface of the MWCNTs significantly improves their solubility and ease of processing. These axially coordinated (5,10,15,20-tetraphenylporphyrinato)tin(Ⅳ) (SnTPP)- MWCNTs exhibit significant fluorescence quenching. The third-order nonlinear optical properties of the resultant nanohybrids were studied by using the Z-scan technique at 532 nm with both nanosecond and picosecond laser pulses. The results show that the nanohybrids exhibit significant reverse saturable absorption or saturable absorption when nanosecond or picosecond pulses, respectively, are employed. Improvement in the nanosecond regime nonlinear absorption is observed on proceeding to the nanohybrids and is ascribed to a combination of the outstanding properties of MWCNTs and the chemically attached metal-porphyrins.
基金This work was supported by the Heilongjiang Touyan Innovation Team Program.The authors gratefully acknowledge the financial support provided by the National Natural Science Foundation of China(Grant Nos.12072094 and 12172106)This work was also supported by the Fundamental Research Funds for the Central Universities(0-1 Original exploration plan,Nos.IR2021106 and IR2021232).
文摘Stent placement is an effective palliation therapy for malignant colorectal obstruction.However,recurrent obstruction is a common severe complication caused by tumor ingrowth into the stent lumen.Conventional covered stents play a part in preventing the tumor from growing inward but at the expense of significantly increasing the risk of stent migration.Therefore,there is an urgent demand to develop stents with sustained antitumor and antimigration abilities.Herein,we propose a facile method for fabricating multifunctional bioinspired colorectal stents using 3D printing technology.Inspired by high-adhesion biological structures(gecko feet,tree frog toe pads,and octopus suckers)in nature,different types of bioinspired colorectal stents are designed to reduce migration.After functionalization with graphene oxide(GO),bioinspired colorectal stents show excellent and controllable photothermal performance,which is validated by effective ablation of colon cancer cells in vitro and tumors in vivo.Besides,the bioinspired colorectal stents demonstrate the feasibility of transanal placement and opening of the obstructed colon.More importantly,the facile manufacturing process of multifunctional bioinspired colorectal stents is appealing for mass production,Hence,the developed multifunctional bioinspired colorectal stents exhibit a highly promising potential in clinical applications.
基金Financial support from the National Natural Science Foundation of China(No.51432006)the Ministry of Science and Technology of China for the International Science Linkages Program(No.2011DFG52970)+2 种基金the Ministry of Education of China for the Changjiang Innovation Research Team(No.IRT14R23)the Ministry of Education and the State Administration of Foreign Experts Affairs for the 111 Project(No.B13025)the Innovation Program of Shanghai Municipal Education Commission are gratefully acknowledged.M.G.H thanks the Australian Research Council(No.DP170100411)for support.
文摘Electron-donating porphyrins(Por),electron-accepting phthalocyanines(Pcs),and reduced graphene oxide(RGO)were integrated into a multicomponent nanoconjugate(Por-RGO-Pc).The donor-π-acceptor nanoconjugate Por-RGO-Pc was characterized using Fourier transform infrared spectroscopy(FTIR),transmission electron microscopy(TEM),scanning electron microscopy(SEM),atomic force microscopy(AFM),and ultraviolet-visible(UV-Vis)spectroscopy.Photoinduced cascading electron/charge transfer from Por to RGO and from RGO to Pc was established from fluorescence,electrochemical,and femtosecond transient absorption(fs-TA)spectroscopy studies.The increased distance between the electron donors and acceptors of the Por-RGO-Pc nanoconjugate compared to the parent materials and the intermediate RGO-Pc results in longlived charge separation,and an enhancement in nonlinear optical(NLO)absorption(a large NLO coefficient of about 827.44 cm/GW)towards nanosecond laser irradiation at 532 nm.
基金the National Natural Science Foundation of China(No.51432006)the Ministry of Science and Technology of China for the International Science Linkages Program(No.2011DFG52970)+2 种基金the Ministry of Education of China for the Changjiang Innovation Research Team(No.IRT14R23)the Ministry of Education and the State Administration of Foreign Experts Affairs for the 111 Project(No.B13025)the Innovation Program of Shanghai Municipal Education Commission are gratefully acknowledged.M.G.H thanks the Australian Research Council(No.DP170100411)for support.
文摘Edge-functionalization of graphene is emerging as a powerful chemical method for the construction ofπ-delocalized highlyplanar graphene nanoconjugates that are not accessible through surface-supported syntheses.Herein,a graphene-porphyrin nanoconjugate via a robust pyrazine(pz)linkage has been obtained by condensing 2,3-diamino-5,10,15,20-tetraphenylporphyrin(DA-TPP)with ortho-quinone(o-quinone)moieties at edge sites of graphene oxide(GO).The as-prepared GO-pz-TPP exhibits an intense absorption extending from 375 to 900 nm and a high quenching yield(98%)of fluorescence,indicating a strong electronic coupling effect between GO and TPP units.GO-pz-TPP displays strong nonlinear optical(NLO)absorption and giant NLO coefficients with 800 and 1,030 nm fs laser,in sharp contrast to traditional graphene-porphyrin nanohybrids only NLO-active towards ns laser.Such a dramatic NLO performance towards femtosecond pulsed laser has not been achieved in any carbonchromophores nanohybridized materials to date.This work validates theπ-extended edge-functionalization strategy as a means to tune the NLO properties of graphene,thereby providing a new paradigm for the assembly of versatile optoelectronic materials.
基金support from the National Natural Science Foundation of China(No.51432006)the Ministry of Science and Technology of China for the International Science Linkages Program(No.2011DFG52970)+2 种基金the Ministry of Education of China for the Changjiang Innovation Research Team(No.IRT14R23)the Ministry of Education and the State Administration of Foreign Experts Affairs for the 111 Project(No.B13025)the Innovation Program of Shanghai Municipal Education Commission.M.G.H thanks the Australian Research Council(No.DP 170100411)for support.
文摘Functional materials displaying large ultrafast third-order optical nonlinearities across a wide spectral region and broad temporal domain are required for all-optical signal processing.Particularly desirable is nonlinear optical(NLO)activity at near-infrared(NIR)wavelengths with femtosecond pulses.Herein the first triply-fused porphyrin dimer(TFP)-functionalized single-walled carbon nanotube(SWCNT)nanohybrid was successfully constructed by covalently grafting TFPs onto SWCNT.The results of Z-scan techniques demonstrate that the newly obtained TFP-SWCNT nanohybrid was found with a strong NLO performance under both nanosecond and femtosecond irradiation.In the nanosecond regime,an enhancement in optical limiting(OL)of the TFP-SWCNT nanohybrid is seen at 532 nm when compared with the performance of porphyrin monomer-functionalized SWCNT nanohybrid Por-SWCNT.Under femtosecond irradiation,the TFP-SWCNT nanohybrid exhibits a particularly strong OL effect with a giant two-photon absorption(TPA)cross section value(ca.15,500 GM)at 800 nm pulses that mainly stems from intense TPA of TFP,in sharp contrast to the Por-SWCNT nanohybrid which exhibits only saturable absorption under identical irradiation.These results demonstrate that the newly-developed TFP-SWCNT nanohybrid is a very promising OL candidate for practical applications across wide spectral and temporal domains,and that covalently functionalizing carbon-based materials with triply-fused chromophores may be a useful approach to engineering adaptable photonic devices with broad-ranging NLO activity.