The traditional teaching methods of one-way cultivation of students can no longer meet the requirements of talent cultivation at this stage.The issue of how to promote students from passive acceptance to the independe...The traditional teaching methods of one-way cultivation of students can no longer meet the requirements of talent cultivation at this stage.The issue of how to promote students from passive acceptance to the independent cognitive understanding stage(i.e.deep learning)has become the focus of geography teaching.Therefore,under the guidance of deep learning theory,this paper takes the“landforms”knowledge unit of the Humanistic Education Edition as an example,improves the classroom teaching means through the unit teaching mode,reconstructs the“landforms”teaching unit,and explores the specific teaching of high school geography unit based on deep learning.This study provides a good example and guidelines for high school geography teaching and learning.展开更多
Background Dairy cows’lactation performance is the outcome of the crosstalk between ruminal microbial metabo-lism and host metabolism.However,it is still unclear to what extent the rumen microbiome and its metabolite...Background Dairy cows’lactation performance is the outcome of the crosstalk between ruminal microbial metabo-lism and host metabolism.However,it is still unclear to what extent the rumen microbiome and its metabolites,as well as the host metabolism,contribute to regulating the milk protein yield(MPY).Methods The rumen fluid,serum and milk of 12 Holstein cows with the same diet(45%coarseness ratio),parity(2–3 fetuses)and lactation days(120–150 d)were used for the microbiome and metabolome analysis.Rumen metabolism(rumen metabolome)and host metabolism(blood and milk metabolome)were connected using a weighted gene co-expression network(WGCNA)and the structural equation model(SEM)analyses.Results Two different ruminal enterotypes,with abundant Prevotella and Ruminococcus,were identified as type1 and type2.Of these,a higher MPY was found in cows with ruminal type2.Interestingly,[Ruminococcus]gauvreauii group and norank_f_Ruminococcaceae(the differential bacteria)were the hub genera of the network.In addition,differential ruminal,serum and milk metabolome between enterotypes were identified,where the cows with type2 had higher L-tyrosine of rumen,ornithine and L-tryptophan of serum,and tetrahydroneopterin,palmitoyl-L-carnitine,S-lactoylglutathione of milk,which could provide more energy and substrate for MPY.Further,based on the identi-fied modules of ruminal microbiome,as well as ruminal serum and milk metabolome using WGCNA,the SEM analysis indicated that the key ruminal microbial module1,which contains the hub genera of the network([Ruminococcus]gauvreauii group and norank_f_Ruminococcaceae)and high abundance of bacteria(Prevotella and Ruminococcus),could regulate the MPY by module7 of rumen,module2 of blood,and module7 of milk,which contained L-tyrosine and L-tryptophan.Therefore,in order to more clearly reveal the process of rumen bacterial regulation of MPY,we established the path of SEM based on the L-tyrosine,L-tryptophan and related components.The SEM based on the metabolites suggested that[Ruminococcus]gauvreauii group could inhibit the energy supply of serum tryptophan to MPY by milk S-lactoylglutathione,which could enhance pyruvate metabolism.Norank_f_Ruminococcaceae could increase the ruminal L-tyrosine,which could provide the substrate for MPY.Conclusion Our results indicated that the represented enterotype genera of Prevotella and Ruminococcus,and the hub genera of[Ruminococcus]gauvreauii group and norank_f_Ruminococcaceae could regulate milk protein synthesis by affecting the ruminal L-tyrosine and L-tryptophan.Moreover,the combined analysis of enterotype,WGCNA and SEM could be used to connect rumen microbial metabolism with host metabolism,which provides a fundamental understanding of the crosstalk between host and microorganisms in regulating the synthesis of milk composition.展开更多
The activation of soil-fixed phosphorus is a long-term concern in soil science. In order to enhance the activation effect to soil-fixed phosphorus in red soil, different modified zeolite, through physical, chemical me...The activation of soil-fixed phosphorus is a long-term concern in soil science. In order to enhance the activation effect to soil-fixed phosphorus in red soil, different modified zeolite, through physical, chemical method and the associated both physics and chemistry, was used in this paper. The results showed as following: 1) the activated ability to soil-fixed phosphorus in red soil for modified zeolite was higher than the common one signally. Order of the ability for all kinds of modification zeolite in absolute activation amount and activation rate was: Modified in high temperature ammonium saturated zeolite > Ammonium saturated zeolite > Modified in high temperature zeolite > Common zeolite. 2) The increasing rate of modified phosphorus in high temperature ammonium saturated zeolite and ammonium saturated zeolite had a decline trend with time postponed while that for modified phosphorus in high temperature zeolite and routine zeolite was rising gradually with time postponed. For ammonium saturated zeolite, the increasing rate of phosphorus in low available phosphorus content red soil was significantly faster than that in red soil with the higher content of available phosphorus. 3) The activation rate for the same modified zeolite showed difference in different phosphorus level soil. The order is: SP<sub>high</sub> > SP<sub>medium</sub> > SP<sub>low</sub>.展开更多
Compound Formula Rehmannia has been shown to be clinically effective in treating Parkinson＇s disease and levodopa-induced dyskinesia; however, the mechanisms remain unclear. In this study, we established a model of P...Compound Formula Rehmannia has been shown to be clinically effective in treating Parkinson＇s disease and levodopa-induced dyskinesia; however, the mechanisms remain unclear. In this study, we established a model of Parkinson＇s disease dyskinesia in rats, and treated these animals with Compound Formula Rehmannia. Compound Formula Rehmannia inhibited the increase in mRNA expression of N-methyl-D-aspartate receptor subunits 1 and 2 and excitatory amino acid neurotransmitter genes, and it inhibited the reduction in expression of γ-aminobutyric acid receptor B1, an inhibitory amino acid neurotransmitter gene, in the corpus striatum. In addition, Compound Formula Rehmannia alleviated dyskinesia symptoms in the Parkinson＇s disease rats. These experimental findings indicate that Compound Formula Rehmannia alleviates levodopa-induced dyskinesia in Parkinson＇s disease by modulating neurotransmitter signaling in the corpus striatum.展开更多
Three types of carbon nano-onions（CNOs） including Ni@CNOs.Fe3C@CNOs and Fe0.64Ni0.36@CNOs nanoparticles have been synthesized by catalytic decomposition of methane at 850 ℃ using nickel,iron and iron-nickel alloy c...Three types of carbon nano-onions（CNOs） including Ni@CNOs.Fe3C@CNOs and Fe0.64Ni0.36@CNOs nanoparticles have been synthesized by catalytic decomposition of methane at 850 ℃ using nickel,iron and iron-nickel alloy catalysts.Comparative and systematic studies have been carried out on the morphology,structural characteristics and graphitic crystallinity of these CNOs products.Furthermore,the electrochemical hydrogen storage properties of three types of CNOs have been investigated.Measurements show that the Ni@CNOs have the highest discharge capacity of 387.2 mAh/g,coiTesponding to a hydrogen storage of 1.42%.This comparison study shows the advantages of each catalyst in the growth of CNOs.enabling the controllable synthesis and tuning the properties of CNOs by mediating different metals and their alloy for using in the fuel cell system.展开更多
The effects of hurricane forward speed(V)and approach angle(θ)on storm surge are important and a systematic investigation covering possible and continuous ranges of these parameters has not been done before.Here we p...The effects of hurricane forward speed(V)and approach angle(θ)on storm surge are important and a systematic investigation covering possible and continuous ranges of these parameters has not been done before.Here we present such a study with a numerical experiment using the Finite Volume Community Ocean Model(FVCOM).The hurricane track is simplified as a straight line,such that V andθfully define the motion of the hurricane.The maximum surge is contributed by both free waves and a forced storm surge wave moving with the hurricane.Among the free waves,Kelvin-type waves can only propagate in the down-coast direction.Simulations show that those waves can only have a significant positive storm surge when the hurricane velocity has a down-coast component.The optimal values of V andθthat maximize the storm surge in an idealized semi-circular ocean basin are functions of the bathymetry.For a constant bathymetry,the maximum surge occurs when the hurricane approaches the coast from the normal direction when the free wave generation is minimal;for a stepped bathymetry,the maximum surge occurs at a certain acute approach angle which maximizes the duration of persistent wind forcing;a step-like bathymetry with a sloped shelf is similar to the stepped bathymetry,with the added possibility of landfall resonance when the free and forced waves are moving at about the same velocity.For other cases,the storm surge is smaller,given other parameters(hurricane size,maximum wind speed,etc.)unchanged.展开更多
In recent years,the occurrence of rice Chilo suppressalis( Walker) in Longyou County of Zhejiang Province has increased year by year and has become aggravated. This poses a great threat to the safety of rice productio...In recent years,the occurrence of rice Chilo suppressalis( Walker) in Longyou County of Zhejiang Province has increased year by year and has become aggravated. This poses a great threat to the safety of rice production. In order to curb the recurrence momentum of rice C. suppressalis,according to the dynamic monitoring and field system survey of rice C. suppressalis in Longyou County since 2015,the causes of the annual increase of rice C. suppressalis in recent years were analyzed,and the recurrence area of C. suppressalis was introduced,and finally some prevention and control measures were put forward.展开更多
To investigate the adverse reactions and efficacy of docetaxel combined with lobaplatin in adjuvant chemotherapy for triple-negative breast cancer in elderly patients.A total of 96 elderly triple-negative breast cance...To investigate the adverse reactions and efficacy of docetaxel combined with lobaplatin in adjuvant chemotherapy for triple-negative breast cancer in elderly patients.A total of 96 elderly triple-negative breast cancer patients admitted to our hospital from January 2008 to December 2011 were randomly divided into two groups.A group of 56 patients received docetaxel 75 mg·m^(-2),intravenous drip,d1;lobaplatin 30 mg·m^(-2),intravenous drip,d1;21 days repeat,a total of 6 cycles.A group of 40 patients received chemotherapy for 6 cycles with an anthracycline-containing(TEC)regimen.Comparison of adverse reactions and 5-year diseasefree survival in both groups.The incidence of thrombocytopenia was significantly higher in 56 patients with TL regimen than those with TCE-containing anthracyclines(P=0.005).But the incidence of cardiotoxicity was 32.5%in the TEC group.And the difference was statistically significant(P=0.008).The 5-year disease-free survival rate was 73.2%in the TL group and 67.5%in the TEC group.There was no statistical difference.Docetaxel combined with lobaplatin in the treatment of elderly triple-negative breast cancer has no significant difference in efficacy compared with traditional anthracycline-containing drugs,but it can avoid the cardiotoxicity caused by anthracyclines.It’s a new option for elderly TNBC adjuvant chemotherapy,suggesting to expand the sample content for further research.展开更多
This paper aims to analyze the data of different crime types in the London area for the past three years. The data is from data.police.uk provided by City of London Police. The R language and ARIMA model were applied ...This paper aims to analyze the data of different crime types in the London area for the past three years. The data is from data.police.uk provided by City of London Police. The R language and ARIMA model were applied to forecast different crime types in London. Seven sets of stable non-white sequences were obtained by preprocessing the original data, stationary test, and non-stationary sequence differential processing. The time series analysis method was used to realize the ARIMA model modelling. After comparison, the prediction was performed with the optimal ARIMA model. In terms of anti-social behaviour (i1), public order (i9), robbery (i10), shoplifting (i11), theft from the person (i12), the predicted results show a small fluctuation. And it shows a large fluctuation trend in bicycle theft (i2), but the overall number is lower than the previous months. Violence and sexual offences (i14) show a downtrend.展开更多
In this article, we used the self-excitation and self-inductance characteristics of polyvinylidene fluoride(PVDF) piezoelectric materials, combined with the powerful signal processing and calculation analysis capabili...In this article, we used the self-excitation and self-inductance characteristics of polyvinylidene fluoride(PVDF) piezoelectric materials, combined with the powerful signal processing and calculation analysis capabilities of integrated circuits, for the first time to explore a set of microcantilever sensor "readout system" without additional driver(self-driving) and can realize self-sensing external signal(self-sensing).It was successfully applied to the unlabeled detection of avian influenza virus(AIV) H9N_(2). The specific force of the antigen-antibody complexes on the surface of the microcantilever leads to the change of the stress of the cantilever, which drives the constructed detection device, and does not require an additional excitation source to drive it, that is, the self-driving part. At the same time, due to the movement of piezoelectric charges in the film caused by the positive piezoelectric effect of the PVDF film, self-inductive charges are generated on the surface of the sensor dielectric. The charge signal is converted into a voltage signal, and the sensing part is completed, that is, self-sensing. The immunosensor has a linear range of100-1000 ng/m L with a detection limit of 2.9 ng/m L. The method will also open up a new avenue for the detection of other analytes based on antigen-antibody responses.展开更多
Herein, carbon nano-onions （CNOs） with different structures have been investigated as precursors for the synthesis of graphene quantum dots （GQDs）. It was found that hollow CNOs yield GQDs with a uniform size dist...Herein, carbon nano-onions （CNOs） with different structures have been investigated as precursors for the synthesis of graphene quantum dots （GQDs）. It was found that hollow CNOs yield GQDs with a uniform size distribution, whereas metal encapsulation in the CNO structure is disadvantageous for the same. Furthermore, the hollow CNOs are also advantageous for the synthesis of GQDs with a yellow-green hybrid luminescence and long-ranged excitation wavelength （λex）-independent photoluminescent （PL） behavior, in which the λex upper limit was 480 nm. These features enable safe sensing and cell tracking applications with a longer excitation wavelength in the visible light region. The potential applications of the synthesized GQDs as fluorescent sensing probes for detecting Cu（II） ions and non-toxic cell imaging under visible light excitation have been demonstrated. This means that sensing and bioimaging can be accomplished in the natural environment with no need for UV excitation. This work provides a reference to researchers in tailoring CNO structures in terms of their inner space to synthesize GQDs with the desired luminescence behavior.展开更多
In the development of wearable energy devices,polypyrrole (PPy) is considered as a promising electrode material owing to its high capacitance and good mechanical flexibility.Herein,we report a PPy-based hybrid structu...In the development of wearable energy devices,polypyrrole (PPy) is considered as a promising electrode material owing to its high capacitance and good mechanical flexibility.Herein,we report a PPy-based hybrid structure consisting of vertical PPy nanotube arrays and carbon nano-onions (CNOs) grown on textile for wearable supercapacitors.In this hybrid nanostructure,the vertical PPy nanotubes provide straight and superhighways for electron and ion transport,boosting the energy storage;while the CNOs mainly act as a conductivity retainer for the underlayered PPy film during stretching.A facile template-degrading method is developed for the large-area growth of the PPy-based hybrid nanostructures on the textile through one-step polymerization process.The fabricated stretchable supercapacitor exhibits superior energy storage capacitance with the specific capacitance of 64 F·g^-1.Also,it presents the high capacitance retention of 99% at a strain of 50% after 500 stretching cycles.Furthermore,we demonstrate that the textile-based stretchable supercapacitor device can provide a stable energy storage performance in different wearable situations for practical applications.The use of the PPy-based hybrid nanostructures as the supercapacitor electrode offers a novel structure design and a promising opportunity for wearable power supply in real applications.展开更多
The anti-bird-strike performance of a lattice-material-infilled curved plate is investigated herein.Since automatically filling the curved structure by classical lattice material filling methods will cause a large num...The anti-bird-strike performance of a lattice-material-infilled curved plate is investigated herein.Since automatically filling the curved structure by classical lattice material filling methods will cause a large number of manufacturing defects,a space-dependent lattice material filling method for the curved plate is firstly proposed in this paper Next,using a face-centered cubic lattice,a lattice-material-infilled test piece with a hollow ratio of 40.8%is built.The test pieces are manufactured via additive manufacturing using titanium alloy.In bird-strike experimental tests,the test pieces are crashed against gelatin birds at an impact velocity of 200 m/s.Dynamic strain gauges are used to record the crash history and the results are discussed.Furthermore,a numerical analysis to simulate the bird-strike experiment is performed.The results from the experimental tests and numerical simulation agree well.This work shows that the lattice-material-infilled curved plate yields promising bird-strike resistance.Therefore,lattice-infilled materials are feasible for protecting aerospace components against bird-strike as well as for reducing the component weight.展开更多
We demonstrate the synthesis of a novel self-anchored catalyst structure containing a Fe-Ni alloy nanosheet generated by phase separation for the substrate-free synthesis of carbon nanostructures. Fast Fourier transfo...We demonstrate the synthesis of a novel self-anchored catalyst structure containing a Fe-Ni alloy nanosheet generated by phase separation for the substrate-free synthesis of carbon nanostructures. Fast Fourier transform analysis was carried out in order to investigate both the phase and structural evolution of the alloy nanosheet during reduction and chemical vapor deposition （CVD） growth. y-Fe-Ni （Feo.64Nio.36） and a-Fe-Ni （kamacite） phases were formed and separated on the NiFe204 nanosheet catalyst precursor during H2 reduction, forming selfanchored mono-dispersed y-Fe-Ni nanocrystals on a a-Fe-Ni matrix. The Fe-Ni alloy nanosheet serves both as a catalyst for growing metal-encapsulated carbon nano-onions （CNOs）, and as a support for anchoring these preformed nano- particles, yielding mono-dispersed catalyst nanoparticles with no requirement of additional substrates for the CVD growth. This synthesis is capable of mitigating the coalescence and Ostwald ripening without the assistance of an additional substrate. This structure allows for the growth of uniform-sized CNOs despite the aggregation, crumbling, and stacking of the alloy sheet. This study provides a promising design for novel catalyst structures by phase separation towards the substrate-free synthesis of carbon nanostructures in large scale. Finally, the ferromagnetic Feo.64Ni0.36@#CNOs particles demonstrate their application in both magnetic storage and water purification, as a non-toxic water treatment material.展开更多
While the Coronavirus Disease 2019(COVID-19)pandemic continues to threaten public health and safety,every state has strategically reopened the business in the United States.It is urgent to evaluate the effect of reope...While the Coronavirus Disease 2019(COVID-19)pandemic continues to threaten public health and safety,every state has strategically reopened the business in the United States.It is urgent to evaluate the effect of reopening policies on the COVID-19 pandemic to help with the decision-making on the control measures and medical resource allocations.In this study,a novel SEIR model was developed to evaluate the effect of reopening policies based on the real-world reported COVID-19 data in Texas.The earlier reported data before the reopening were used to develop the SEIR model;data after the reopening were used for evaluation.The simulation results show that if continuing the“stay-at-home order”without reopening the business,the COVID-19 pandemic could end in December 2020 in Texas.On the other hand,the pandemic could be controlled similarly as the case of noreopening only if the contact rate was low and additional high magnitude of control measures could be implemented.If the control measures are only slightly enhanced after reopening,it could flatten the curve of the COVID-19 epidemic with reduced numbers of infections and deaths,but it might make the epidemic last longer.Based on the reported data up to July 2020 in Texas,the real-world epidemic pattern is between the cases of the low and high magnitude of control measures with a medium risk of contact rate after reopening.In this case,the pandemic might last until summer 2021 to February 2022 with a total of 4-10 million infected cases and 20,080e58,604 deaths.展开更多
文摘The traditional teaching methods of one-way cultivation of students can no longer meet the requirements of talent cultivation at this stage.The issue of how to promote students from passive acceptance to the independent cognitive understanding stage(i.e.deep learning)has become the focus of geography teaching.Therefore,under the guidance of deep learning theory,this paper takes the“landforms”knowledge unit of the Humanistic Education Edition as an example,improves the classroom teaching means through the unit teaching mode,reconstructs the“landforms”teaching unit,and explores the specific teaching of high school geography unit based on deep learning.This study provides a good example and guidelines for high school geography teaching and learning.
基金the National Natural Science Foundation of China(32272829,32072761,31902184)Shaanxi Provincial Science and Technology Association Young Talents Lifting Program Project(20220203).
文摘Background Dairy cows’lactation performance is the outcome of the crosstalk between ruminal microbial metabo-lism and host metabolism.However,it is still unclear to what extent the rumen microbiome and its metabolites,as well as the host metabolism,contribute to regulating the milk protein yield(MPY).Methods The rumen fluid,serum and milk of 12 Holstein cows with the same diet(45%coarseness ratio),parity(2–3 fetuses)and lactation days(120–150 d)were used for the microbiome and metabolome analysis.Rumen metabolism(rumen metabolome)and host metabolism(blood and milk metabolome)were connected using a weighted gene co-expression network(WGCNA)and the structural equation model(SEM)analyses.Results Two different ruminal enterotypes,with abundant Prevotella and Ruminococcus,were identified as type1 and type2.Of these,a higher MPY was found in cows with ruminal type2.Interestingly,[Ruminococcus]gauvreauii group and norank_f_Ruminococcaceae(the differential bacteria)were the hub genera of the network.In addition,differential ruminal,serum and milk metabolome between enterotypes were identified,where the cows with type2 had higher L-tyrosine of rumen,ornithine and L-tryptophan of serum,and tetrahydroneopterin,palmitoyl-L-carnitine,S-lactoylglutathione of milk,which could provide more energy and substrate for MPY.Further,based on the identi-fied modules of ruminal microbiome,as well as ruminal serum and milk metabolome using WGCNA,the SEM analysis indicated that the key ruminal microbial module1,which contains the hub genera of the network([Ruminococcus]gauvreauii group and norank_f_Ruminococcaceae)and high abundance of bacteria(Prevotella and Ruminococcus),could regulate the MPY by module7 of rumen,module2 of blood,and module7 of milk,which contained L-tyrosine and L-tryptophan.Therefore,in order to more clearly reveal the process of rumen bacterial regulation of MPY,we established the path of SEM based on the L-tyrosine,L-tryptophan and related components.The SEM based on the metabolites suggested that[Ruminococcus]gauvreauii group could inhibit the energy supply of serum tryptophan to MPY by milk S-lactoylglutathione,which could enhance pyruvate metabolism.Norank_f_Ruminococcaceae could increase the ruminal L-tyrosine,which could provide the substrate for MPY.Conclusion Our results indicated that the represented enterotype genera of Prevotella and Ruminococcus,and the hub genera of[Ruminococcus]gauvreauii group and norank_f_Ruminococcaceae could regulate milk protein synthesis by affecting the ruminal L-tyrosine and L-tryptophan.Moreover,the combined analysis of enterotype,WGCNA and SEM could be used to connect rumen microbial metabolism with host metabolism,which provides a fundamental understanding of the crosstalk between host and microorganisms in regulating the synthesis of milk composition.
文摘The activation of soil-fixed phosphorus is a long-term concern in soil science. In order to enhance the activation effect to soil-fixed phosphorus in red soil, different modified zeolite, through physical, chemical method and the associated both physics and chemistry, was used in this paper. The results showed as following: 1) the activated ability to soil-fixed phosphorus in red soil for modified zeolite was higher than the common one signally. Order of the ability for all kinds of modification zeolite in absolute activation amount and activation rate was: Modified in high temperature ammonium saturated zeolite > Ammonium saturated zeolite > Modified in high temperature zeolite > Common zeolite. 2) The increasing rate of modified phosphorus in high temperature ammonium saturated zeolite and ammonium saturated zeolite had a decline trend with time postponed while that for modified phosphorus in high temperature zeolite and routine zeolite was rising gradually with time postponed. For ammonium saturated zeolite, the increasing rate of phosphorus in low available phosphorus content red soil was significantly faster than that in red soil with the higher content of available phosphorus. 3) The activation rate for the same modified zeolite showed difference in different phosphorus level soil. The order is: SP<sub>high</sub> > SP<sub>medium</sub> > SP<sub>low</sub>.
基金supported by the National Natural Science Foundation of China,No.30672684,30973722Science and Technology Support Traditional Chinese Drug Research and Development Project of Shanghai,No.F50102+1 种基金Traditional Chinese Medicine Research Fund of Shanghai Municipal Health Bureau,No.2012J009AAnnual Research Budget of Shanghai University of Traditional Chinese Medicine in 2013,No.2013JW25
文摘Compound Formula Rehmannia has been shown to be clinically effective in treating Parkinson＇s disease and levodopa-induced dyskinesia; however, the mechanisms remain unclear. In this study, we established a model of Parkinson＇s disease dyskinesia in rats, and treated these animals with Compound Formula Rehmannia. Compound Formula Rehmannia inhibited the increase in mRNA expression of N-methyl-D-aspartate receptor subunits 1 and 2 and excitatory amino acid neurotransmitter genes, and it inhibited the reduction in expression of γ-aminobutyric acid receptor B1, an inhibitory amino acid neurotransmitter gene, in the corpus striatum. In addition, Compound Formula Rehmannia alleviated dyskinesia symptoms in the Parkinson＇s disease rats. These experimental findings indicate that Compound Formula Rehmannia alleviates levodopa-induced dyskinesia in Parkinson＇s disease by modulating neurotransmitter signaling in the corpus striatum.
基金supported by the National Natural Science Foundation of China(51272173,51002188)the National Basic Research Program of China(2010CB934703)Tianjin Municipal Science and Technology Commission(12ZCZDGX00800)
文摘Three types of carbon nano-onions（CNOs） including Ni@CNOs.Fe3C@CNOs and Fe0.64Ni0.36@CNOs nanoparticles have been synthesized by catalytic decomposition of methane at 850 ℃ using nickel,iron and iron-nickel alloy catalysts.Comparative and systematic studies have been carried out on the morphology,structural characteristics and graphitic crystallinity of these CNOs products.Furthermore,the electrochemical hydrogen storage properties of three types of CNOs have been investigated.Measurements show that the Ni@CNOs have the highest discharge capacity of 387.2 mAh/g,coiTesponding to a hydrogen storage of 1.42%.This comparison study shows the advantages of each catalyst in the growth of CNOs.enabling the controllable synthesis and tuning the properties of CNOs by mediating different metals and their alloy for using in the fuel cell system.
基金The National Key R&D Project under contract No.2017YFC1404201
文摘The effects of hurricane forward speed(V)and approach angle(θ)on storm surge are important and a systematic investigation covering possible and continuous ranges of these parameters has not been done before.Here we present such a study with a numerical experiment using the Finite Volume Community Ocean Model(FVCOM).The hurricane track is simplified as a straight line,such that V andθfully define the motion of the hurricane.The maximum surge is contributed by both free waves and a forced storm surge wave moving with the hurricane.Among the free waves,Kelvin-type waves can only propagate in the down-coast direction.Simulations show that those waves can only have a significant positive storm surge when the hurricane velocity has a down-coast component.The optimal values of V andθthat maximize the storm surge in an idealized semi-circular ocean basin are functions of the bathymetry.For a constant bathymetry,the maximum surge occurs when the hurricane approaches the coast from the normal direction when the free wave generation is minimal;for a stepped bathymetry,the maximum surge occurs at a certain acute approach angle which maximizes the duration of persistent wind forcing;a step-like bathymetry with a sloped shelf is similar to the stepped bathymetry,with the added possibility of landfall resonance when the free and forced waves are moving at about the same velocity.For other cases,the storm surge is smaller,given other parameters(hurricane size,maximum wind speed,etc.)unchanged.
文摘In recent years,the occurrence of rice Chilo suppressalis( Walker) in Longyou County of Zhejiang Province has increased year by year and has become aggravated. This poses a great threat to the safety of rice production. In order to curb the recurrence momentum of rice C. suppressalis,according to the dynamic monitoring and field system survey of rice C. suppressalis in Longyou County since 2015,the causes of the annual increase of rice C. suppressalis in recent years were analyzed,and the recurrence area of C. suppressalis was introduced,and finally some prevention and control measures were put forward.
基金Natural Science Fund of Xinjiang Uygur Autonomous Region(2017D01C407)。
文摘To investigate the adverse reactions and efficacy of docetaxel combined with lobaplatin in adjuvant chemotherapy for triple-negative breast cancer in elderly patients.A total of 96 elderly triple-negative breast cancer patients admitted to our hospital from January 2008 to December 2011 were randomly divided into two groups.A group of 56 patients received docetaxel 75 mg·m^(-2),intravenous drip,d1;lobaplatin 30 mg·m^(-2),intravenous drip,d1;21 days repeat,a total of 6 cycles.A group of 40 patients received chemotherapy for 6 cycles with an anthracycline-containing(TEC)regimen.Comparison of adverse reactions and 5-year diseasefree survival in both groups.The incidence of thrombocytopenia was significantly higher in 56 patients with TL regimen than those with TCE-containing anthracyclines(P=0.005).But the incidence of cardiotoxicity was 32.5%in the TEC group.And the difference was statistically significant(P=0.008).The 5-year disease-free survival rate was 73.2%in the TL group and 67.5%in the TEC group.There was no statistical difference.Docetaxel combined with lobaplatin in the treatment of elderly triple-negative breast cancer has no significant difference in efficacy compared with traditional anthracycline-containing drugs,but it can avoid the cardiotoxicity caused by anthracyclines.It’s a new option for elderly TNBC adjuvant chemotherapy,suggesting to expand the sample content for further research.
文摘This paper aims to analyze the data of different crime types in the London area for the past three years. The data is from data.police.uk provided by City of London Police. The R language and ARIMA model were applied to forecast different crime types in London. Seven sets of stable non-white sequences were obtained by preprocessing the original data, stationary test, and non-stationary sequence differential processing. The time series analysis method was used to realize the ARIMA model modelling. After comparison, the prediction was performed with the optimal ARIMA model. In terms of anti-social behaviour (i1), public order (i9), robbery (i10), shoplifting (i11), theft from the person (i12), the predicted results show a small fluctuation. And it shows a large fluctuation trend in bicycle theft (i2), but the overall number is lower than the previous months. Violence and sexual offences (i14) show a downtrend.
基金the financial support from National Natural Science Foundation of China (No. 22102141)the Priority Academic Program Development of Jiangsu Higher Education Institutions (PAPD)+2 种基金Nature Science Foundation of Jiangsu Province No.BK20190905Project for Science and Technology of Yangzhou(No. YZ2020067)the open funds of the Ministry of Education Key Lab for Avian Preventive Medicine (No. YF202020)。
文摘In this article, we used the self-excitation and self-inductance characteristics of polyvinylidene fluoride(PVDF) piezoelectric materials, combined with the powerful signal processing and calculation analysis capabilities of integrated circuits, for the first time to explore a set of microcantilever sensor "readout system" without additional driver(self-driving) and can realize self-sensing external signal(self-sensing).It was successfully applied to the unlabeled detection of avian influenza virus(AIV) H9N_(2). The specific force of the antigen-antibody complexes on the surface of the microcantilever leads to the change of the stress of the cantilever, which drives the constructed detection device, and does not require an additional excitation source to drive it, that is, the self-driving part. At the same time, due to the movement of piezoelectric charges in the film caused by the positive piezoelectric effect of the PVDF film, self-inductive charges are generated on the surface of the sensor dielectric. The charge signal is converted into a voltage signal, and the sensing part is completed, that is, self-sensing. The immunosensor has a linear range of100-1000 ng/m L with a detection limit of 2.9 ng/m L. The method will also open up a new avenue for the detection of other analytes based on antigen-antibody responses.
文摘Herein, carbon nano-onions （CNOs） with different structures have been investigated as precursors for the synthesis of graphene quantum dots （GQDs）. It was found that hollow CNOs yield GQDs with a uniform size distribution, whereas metal encapsulation in the CNO structure is disadvantageous for the same. Furthermore, the hollow CNOs are also advantageous for the synthesis of GQDs with a yellow-green hybrid luminescence and long-ranged excitation wavelength （λex）-independent photoluminescent （PL） behavior, in which the λex upper limit was 480 nm. These features enable safe sensing and cell tracking applications with a longer excitation wavelength in the visible light region. The potential applications of the synthesized GQDs as fluorescent sensing probes for detecting Cu（II） ions and non-toxic cell imaging under visible light excitation have been demonstrated. This means that sensing and bioimaging can be accomplished in the natural environment with no need for UV excitation. This work provides a reference to researchers in tailoring CNO structures in terms of their inner space to synthesize GQDs with the desired luminescence behavior.
基金the National Natural Science Foundation of China (No.51702233)the Natural Science Foundation of Tianjin City (No.16JCYBJC41000)support by Tianjin Key Subject for Materials Physics and Chemistry.
文摘In the development of wearable energy devices,polypyrrole (PPy) is considered as a promising electrode material owing to its high capacitance and good mechanical flexibility.Herein,we report a PPy-based hybrid structure consisting of vertical PPy nanotube arrays and carbon nano-onions (CNOs) grown on textile for wearable supercapacitors.In this hybrid nanostructure,the vertical PPy nanotubes provide straight and superhighways for electron and ion transport,boosting the energy storage;while the CNOs mainly act as a conductivity retainer for the underlayered PPy film during stretching.A facile template-degrading method is developed for the large-area growth of the PPy-based hybrid nanostructures on the textile through one-step polymerization process.The fabricated stretchable supercapacitor exhibits superior energy storage capacitance with the specific capacitance of 64 F·g^-1.Also,it presents the high capacitance retention of 99% at a strain of 50% after 500 stretching cycles.Furthermore,we demonstrate that the textile-based stretchable supercapacitor device can provide a stable energy storage performance in different wearable situations for practical applications.The use of the PPy-based hybrid nanostructures as the supercapacitor electrode offers a novel structure design and a promising opportunity for wearable power supply in real applications.
基金provided by National Key R&D Program of China(2018YFB1106400)National Natural Science Foundation of China(11672057,11702052,U1906233)+1 种基金Aeronautical Science Foundation of China(2018ZB63002)China Postdoctoral Science Foundation(2018M640251,2019T120201)。
文摘The anti-bird-strike performance of a lattice-material-infilled curved plate is investigated herein.Since automatically filling the curved structure by classical lattice material filling methods will cause a large number of manufacturing defects,a space-dependent lattice material filling method for the curved plate is firstly proposed in this paper Next,using a face-centered cubic lattice,a lattice-material-infilled test piece with a hollow ratio of 40.8%is built.The test pieces are manufactured via additive manufacturing using titanium alloy.In bird-strike experimental tests,the test pieces are crashed against gelatin birds at an impact velocity of 200 m/s.Dynamic strain gauges are used to record the crash history and the results are discussed.Furthermore,a numerical analysis to simulate the bird-strike experiment is performed.The results from the experimental tests and numerical simulation agree well.This work shows that the lattice-material-infilled curved plate yields promising bird-strike resistance.Therefore,lattice-infilled materials are feasible for protecting aerospace components against bird-strike as well as for reducing the component weight.
基金The authors acknowledge the finance support by the National Natural Science Foundation of China （Nos. 51531004 and 51272173） and Foundation for SinoEuro Cooperative Project from Chinese Ministry of Science and Technology （No. SQ2013ZOA100006）. The authors also acknowledge helpful discussion with Dr. Jiancan Yu in Nanyang Technological University in Singapore.
文摘We demonstrate the synthesis of a novel self-anchored catalyst structure containing a Fe-Ni alloy nanosheet generated by phase separation for the substrate-free synthesis of carbon nanostructures. Fast Fourier transform analysis was carried out in order to investigate both the phase and structural evolution of the alloy nanosheet during reduction and chemical vapor deposition （CVD） growth. y-Fe-Ni （Feo.64Nio.36） and a-Fe-Ni （kamacite） phases were formed and separated on the NiFe204 nanosheet catalyst precursor during H2 reduction, forming selfanchored mono-dispersed y-Fe-Ni nanocrystals on a a-Fe-Ni matrix. The Fe-Ni alloy nanosheet serves both as a catalyst for growing metal-encapsulated carbon nano-onions （CNOs）, and as a support for anchoring these preformed nano- particles, yielding mono-dispersed catalyst nanoparticles with no requirement of additional substrates for the CVD growth. This synthesis is capable of mitigating the coalescence and Ostwald ripening without the assistance of an additional substrate. This structure allows for the growth of uniform-sized CNOs despite the aggregation, crumbling, and stacking of the alloy sheet. This study provides a promising design for novel catalyst structures by phase separation towards the substrate-free synthesis of carbon nanostructures in large scale. Finally, the ferromagnetic Feo.64Ni0.36@#CNOs particles demonstrate their application in both magnetic storage and water purification, as a non-toxic water treatment material.
基金This project is partially supported by NIH grant R01 AI087135 and the Center for Big Data in Health Sciences(CBD-HS)at School of Public Health,The University of Texas Health Science Center at Houston,UTHealth.
文摘While the Coronavirus Disease 2019(COVID-19)pandemic continues to threaten public health and safety,every state has strategically reopened the business in the United States.It is urgent to evaluate the effect of reopening policies on the COVID-19 pandemic to help with the decision-making on the control measures and medical resource allocations.In this study,a novel SEIR model was developed to evaluate the effect of reopening policies based on the real-world reported COVID-19 data in Texas.The earlier reported data before the reopening were used to develop the SEIR model;data after the reopening were used for evaluation.The simulation results show that if continuing the“stay-at-home order”without reopening the business,the COVID-19 pandemic could end in December 2020 in Texas.On the other hand,the pandemic could be controlled similarly as the case of noreopening only if the contact rate was low and additional high magnitude of control measures could be implemented.If the control measures are only slightly enhanced after reopening,it could flatten the curve of the COVID-19 epidemic with reduced numbers of infections and deaths,but it might make the epidemic last longer.Based on the reported data up to July 2020 in Texas,the real-world epidemic pattern is between the cases of the low and high magnitude of control measures with a medium risk of contact rate after reopening.In this case,the pandemic might last until summer 2021 to February 2022 with a total of 4-10 million infected cases and 20,080e58,604 deaths.
