This editorial contains comments on the article“Correlation between preoperative systemic immune inflammation index,nutritional risk index,and prognosis of radical resection of liver cancer”in a recent issue of the ...This editorial contains comments on the article“Correlation between preoperative systemic immune inflammation index,nutritional risk index,and prognosis of radical resection of liver cancer”in a recent issue of the World Journal of Gastrointestinal Surgery.It pointed out the actuality and importance of the article and focused primarily on the underlying mechanisms making the systemic immuneinflammation index(SII)and geriatric nutritional risk index(GNRI)prediction features valuable.There are few publications on both SII and GNRI together in hepatocellular carcinoma(HCC)and patient prognosis after radical surgery.Neutrophils release cytokines,chemokines,and enzymes,degrade extracellular matrix,reduce cell adhesion,and create conditions for tumor cell invasion.Neutrophils promote the adhesion of tumor cells to endothelial cells,through physical anchoring.That results in the migration of tumor cells.Pro-angiogenic factors from platelets enhance tumor angiogenesis to meet tumor cell supply needs.Platelets can form a protective film on the surface of tumor cells.This allows avoiding blood flow damage as well as immune system attack.It also induces the epithelial-mesenchymal transformation of tumor cells that is critical for invasiveness.High SII is also associated with macro-and microvascular invasion and increased numbers of circulating tumor cells.A high GNRI was associated with significantly better progression-free and overall survival.HCC patients are a very special population that requires increased attention.SII and GNRI have significant survival prediction value in both palliative treatment and radical surgery settings.The underlying mechanisms of their possible predictive properties lie in the field of essential cancer features.Those features provide tumor nutrition,growth,and distribution throughout the body,such as vascular invasion.On the other hand,they are tied to the possibility of patients to resist tumor progression and development of complications in both postoperative and cancer-related settings.The article is of considerable interest.It would be helpful to continue the study follow-up to 2 years and longer.External validation of the data is needed.展开更多
This editorial contains comments on the article“Systematic sequential therapy for ex vivo liver resection and autotransplantation:A case report and review of li-terature”in the recent issue of World Journal of Gastr...This editorial contains comments on the article“Systematic sequential therapy for ex vivo liver resection and autotransplantation:A case report and review of li-terature”in the recent issue of World Journal of Gastrointestinal Surgery.It points out the actuality and importance of the article and focuses primarily on the role and place of ex vivo liver resection and autotransplantation(ELRAT)and systemic therapy,underlying molecular mechanisms for targeted therapy in perihilar cho-langiocarcinoma(pCCA)management.pCCA is a tough malignancy with a high proportion of advanced disease at the time of diagnosis.The only curative option is radical surgery.Surgical excision and reconstruction become extremely com-plicated and not always could be performed even in localized disease.On the other hand,ELRAT takes its place among surgical options for carefully selected pCCA patients.In advanced disease,systemic therapy becomes a viable option to prolong survival.This editorial describes current possibilities in chemotherapy and reveals underlying mechanisms and projections in targeted therapy with ki-nase inhibitors and immunotherapy in both palliative and adjuvant settings.Fi-broblast grow factor and fibroblast grow factor receptor,human epidermal grow-th factor receptor 2,isocitrate dehydrogenase,and protein kinase cAMP activated catalytic subunit alpha(PRKACA)and beta(PRKACB)pathways have been ac-tively investigated in CCA in last years.Several agents were introduced and approved by the Food and Drug Administration.They all demonstrated mean-ingful activity in CCA patients with no global change in outcomes.That is why every successfully treated patient counts,especially those with advanced disease.In conclusion,pCCA is still hard to treat due to late diagnosis and extremely complicated surgical options.ELRAT also brings some hope,but it could be performed in very carefully selected patients.Advanced disease requires systemic anticancer treatment,which is supposed to be individualized according to the genetic and molecular features of cancer cells.Targeted therapy in combination with chemo-immunotherapy could be effective in susceptible patients.展开更多
The dynamics of a bilayer system filling a rectangular cuvette subjected to external heating is studied.The influence of two types of thermal exposure on the flow pattern and on the dynamic contact angle is analyzed.I...The dynamics of a bilayer system filling a rectangular cuvette subjected to external heating is studied.The influence of two types of thermal exposure on the flow pattern and on the dynamic contact angle is analyzed.In particular,the cases of local heating from below and distributed thermal load from the lateral walls are considered.The simulation is carried out within the frame of a two-sided evaporative convection model based on the Boussinesq approximation.A benzine–air system is considered as reference system.The variation in time of the contact angle is described for both heating modes.Under lateral heating,near-wall boundary layers emerge together with strong convection,whereas the local thermal load from the lower wall results in the formation of multicellular motion in the entire volume of the fluids and the appearance of transition regimes followed by a steady-state mode.The results of the present study can aid the design of equipment for thermal coating or drying and the development of methods for the formation of patterns with required structure and morphology.展开更多
The existing approaches for the design of tourist areas often lead to limited flexibility in project implementation.To realize a more flexible approach,in this study,we formulated a model for planning and designing to...The existing approaches for the design of tourist areas often lead to limited flexibility in project implementation.To realize a more flexible approach,in this study,we formulated a model for planning and designing tourist areas at the local level.Moreover,specific tools for analyzing tourist areas and ensuring sustainable development under changing conditions were developed.This study was conducted in two tourist regions,Biryuzovaya Katun tourist complex and Belokurikha destination(including Belokurikha City with Belokurikha 2 Gornaya tourist complex and surrounding areas),in the Altay Mountains.We employed the recreation opportunity spectrum and proposed a system-integrated programming approach for the design of tourist areas at the destination and site levels.The key of this approach was the collection and analysis of current spatial data,including the spatial distribution of attractions and visitor flows.We constructed heat maps using video recording and unmanned aerial vehicle(UAV)observation data.Moreover,we analyzed the video stream using an image-analyzing framework You Only Look Once(YOLO)v5 software.The heat map of visitor flows based on video recording data in the Andreevskaya Sloboda museum of Belokurikha 2 Gornaya tourist complex allowed us to highlight the most attractive sites in this area and classify them into one of three types:points of functional concentration,points of transitional concentration,and points of attractions.The heat maps in Biryuzovaya Katun tourist complex,created using UAV observation data,allowed us to determine the spatiotemporal patterns of visitor flows and tourists’preferences throughout the day within four time intervals:09:00-12:00,13:00-14:00,14:00-15:00,and 16:00-18:00(LST).The maximum visitor flow density occurred from 16:00 to 18:00 in the beach area of the artificial lake.A comparison between the visitor-concentrated sites and the current facilities provided insights into the demand for attractions and facilities and the lacking areas.Heat maps are useful in analyzing the land use at the site level,while zoning based on the recreation opportunity spectrum can be used to design tourist areas at the destination level.The proposed methods for analyzing the use of tourist areas contribute to the development of adaptive tourism design.展开更多
In this work,selective laser melting(SLM)process is used to prepare the AlNi6TiZr alloy.By analyzing the printing quality and mechanical properties of the printed specimens with different process parameters,the SLM fo...In this work,selective laser melting(SLM)process is used to prepare the AlNi6TiZr alloy.By analyzing the printing quality and mechanical properties of the printed specimens with different process parameters,the SLM forming window of AlNi6TiZr is obtained.The relative density of the sample printed with 270 W-1100 mm/s(laser energy density:82 J/mm3)reaches 99.7%,exhibiting excellent mechanical properties(yield strength(YS):421.7 MPa;ultimate tensile strength(UTS):480.4 MPa).After an aging treatment of 325 ℃-12 h,the YS and UTS of the sample increased to 494 MPa and 550.7 MPa,respectively.Adding Ni,Ti,and Zr components promoted the generation of multi-phase precipitates in the Al alloy and improved the synergistic strengthening effect of multi-phases.The hard-shell structure(HSS)formed by the Al_(3)Ni phase at the grain boundary significantly strengthened the grain boundary strength.The precipitated Al_(3)(Ti,Zr)phases at the grain boundaries prevent grain growth and dislocation movement.The Al_(3)Ni and Al_(3)(Ti,Zr)phases have good thermal stability that can still maintain excellent enhancement effects at high temperature.AlNi6TiZr alloy has great application prospects in medium and high-temperature environments.展开更多
The growing demand for donor organs requires measures to expand donor pool.Those include extended criteria donors, such as elderly people, steatotic livers,donation after cardiac death, etc. Static cold storage to red...The growing demand for donor organs requires measures to expand donor pool.Those include extended criteria donors, such as elderly people, steatotic livers,donation after cardiac death, etc. Static cold storage to reduce metabolic requirements developed by Collins in late 1960 s is the mainstay and the golden standard for donated organ protection. Hypothermic machine perfusion provides dynamic organ preservation at 4°C with protracted infusion of metabolic substrates to the graft during the ex vivo period. It has been used instead of static cold storage or after it as short perfusion in transplant center. Normothermic machine perfusion(NMP) delivers oxygen, and nutrition at physiological temperature mimicking regular environment in order to support cellular function. This would minimize effects of ischemia/reperfusion injury.Potentially, NMP may help to estimate graft functionality before implantation into a recipient. Clinical studies demonstrated at least its non-inferiority or better outcomes vs static cold storage. Regular grafts donated after brain death could be safely preserved with convenient static cold storage. Except for prolonged ischemia time where hypothermic machine perfusion started in transplant center could be estimated to provide possible positive reconditioning effect. Use of hypothermic machine perfusion in regular donation instead of static cold storage or in extended criteria donors requires further investigation. Multicenter randomized clinical trial supposed to be completed in December 2021. Extended criteria donors need additional measures for graft storage and assessment until its implantation. NMP is actively evaluating promising method for this purpose.Future studies are necessary for precise estimation and confirmation to issue clinical practice recommendations.展开更多
The aim of this investigation was to define the effectiveness of non-contact drying using ultrasonic vibrations. Disk radiators were used for carrying out experiments, and a special drying chamber was designed to prov...The aim of this investigation was to define the effectiveness of non-contact drying using ultrasonic vibrations. Disk radiators were used for carrying out experiments, and a special drying chamber was designed to provide resonant amplification of ultrasonic vibrations (from 130 to 150 dB). Drying of ginseng and other vegetables demonstrated that the application of ultrasonic vibrations reduced power inputs by 20% in comparison with convective drying. It also led to a decrease of 6% in final moisture content, if the duration of drying was constant. The level of intensification of ultrasonic drying was high (up to 50 g for 1 kg of drying material), which helped to lower the temperature of the drying agent and improve the quality of the dried products.展开更多
The selective laser melting(SLM)processed aluminum alloys have already aroused researchers’attention in aerospace,rail transport and petrochemical engineering due to the comprehensive advantages of low density,good c...The selective laser melting(SLM)processed aluminum alloys have already aroused researchers’attention in aerospace,rail transport and petrochemical engineering due to the comprehensive advantages of low density,good corrosion resistance and high mechanical performance.In this paper,an Al-14.1Mg-0.47Si-0.31Sc-0.17Zr alloy was fabricated via SLM.The characteristics of single track at different process parameters,and the influence of hatch spacing on densification,microstructural features and tensile properties of block specimens were systematically studied.The hatch spacing has an influence on the overlap ratio of single track,and further affects the internal forming quality of printed specimen.At a laser power of 160 W and scanning speed of 400 mm/s,the densification of block specimen increased first and then decreased with the increase of hatch spacing.The nearly full dense specimen(98.7%)with a tensile strength of 452 MPa was fabricated at a hatch spacing of 80μm.Typical characteristics of dimple and cleavage on the tensile fracture of the AlMgSiScZr alloy showed the mixed fracture of ductility and brittleness.展开更多
The paper proposes an experimental method of material inspection,which is based on digital processing of multi-frequency eddy current measurement data.The influences of various factors(conductivity,the gap between the...The paper proposes an experimental method of material inspection,which is based on digital processing of multi-frequency eddy current measurement data.The influences of various factors(conductivity,the gap between the sample surface and the sensor,the thickness of the sample) on the obtained hodographs are examined by taking the aluminum alloys for example,and the possibility of separation of various factors is analyzed.The results obtained are indicative of how much promise the proposed method offers for the inspection and testing of products made of aluminum alloys.展开更多
A critical revision of the collections of Brassicaceae in some Chinese （PE, XJA, XJBI, XJFA, XJNM, XJU） and foreign （LE, P） herbaria is made. One genus, Neurotropis （DC.） E K. Mey., and 11 species, Alyssum szara...A critical revision of the collections of Brassicaceae in some Chinese （PE, XJA, XJBI, XJFA, XJNM, XJU） and foreign （LE, P） herbaria is made. One genus, Neurotropis （DC.） E K. Mey., and 11 species, Alyssum szarabiacum Nyar., Barbarea stricta Andrz., Erysimum czernjajevii N. Busch, Erysimum kotuchovii D. German, Erysimum mongolicum D. German, Lepidium karelinianum Al-Shehbaz, Matthiola superba Conti, Neurotropis platycarpa （Fisch. ＆ Mey.） E K. Mey., Ptilotrichum dahuricum Peschkova, Sisymbrium subspinescens Bunge, and Smelowskia micrantha （Botsch. ＆ Vved.） Al-Shehbaz ＆ S. I. Warwick, are reported from China for the first time. Six species, Aphragmus involucratus （Bunge） O. E. Schulz, Dontostemonperennis C. A. Mey., Goldbachia torulosa DC., Lepidium amplexicaule Willd., Neotorularia brevipes （Kar. ＆ Kir.） Hedge ＆ J. Leonard, and Parrya stenocarpa Kar. ＆ Kir., are confirmed to occurr in China. Five species, Dontostemon integrifolius （L.） C. A. Mey., Draba zangbeiensis L. L. Lou, Lepidium alashanicum H. L. Yang, Sinapis arvensis L., and Strigosella brevipes （Bunge） Botsch., are reported as novelties for some provinces in China, and Strigosella hispida （Litv.） Botsch. occurs in Xinjiang, China. However, the occurrence of one genus, Pseudoarabidopsis Al-Shehbaz, O＇Kane ＆ Price, and four species, Draba huetii Boiss., Eutrema halophilum （C. A. Mey.） Al-Shehbaz ＆ S. I. Warwick, Galitzkya spathulata （Steph. ex Willd.） V. Bocz., and Pseudoarabidopsis toxophylla （Bieb.） Al-Shehbaz, O＇Kane ＆ Price, could not be confirmed in China. The occurrence of six species, Aphragmus bouffordii Al-Shehbaz, Barbarea orthoceras Ledeb., Lepidium latifolium L., Ptilotrichum canescens （DC.） C. A. Mey., Strigosella hispida （Litv.） Botsch., and Strigosella scorpioides （Bunge） Botsch., is not confirmed in certain provinces of China. All names follow the latest taxonomic treatment for relevant groups; detailed morphological descriptions of the newly recorded taxa are provided; and distinguishing characters from related species already known in China are discussed. Other comments are provided where needed.展开更多
The aim of this paper is to analyze fluctuation in nutritional value of Dactylis glomerata and Festuca pratensis varieties grown on mineral and organic soil. Moreover, the paper deals with analysis of their nutritiona...The aim of this paper is to analyze fluctuation in nutritional value of Dactylis glomerata and Festuca pratensis varieties grown on mineral and organic soil. Moreover, the paper deals with analysis of their nutritional value in terms of animal feeding. This paper has drawn on two field experiments set up and carried out between 2010 and 2013 by the Research Centre for Cultivar Testing in Slupia Wielka. The experiment was conducted in two experimental stations： one in the Research Centre for Cultivar Testing in Krzyzewo and the other in the Experimental Stations for Variety Testing in Uhinin, being a branch of the Research Centre for Cultivar Testing in Cicibor Duzy. The experiment was arranged and conducted according to COBORU guidelines. The experimental plots were sown with varieties of Dactylis glornerata： Niva, Tukan, Amila, Crown Royale and with varieties of Festuca pratensis： Limosa, Pasja, Anturka, Amelka （d. AND 1009）. In the experimental plots with the varieties of Dactylis glornerata the grass was harvested six times a year and chemical analysis of the biomass was done taking dry matter only from five cuts. The varieties of Festuca pratensis were harvested four times. The RFV （relative feed value） was determined using the Linn and Martin method. Linn and Martin＇s test proved that Festuca pratensis had better nutritional value than Dactylis glomerata. For Dactylis glomerata, no matter what the variety and location was, the relative feed value ranged from 125 to 151, which puts that grass species in II quality class, good enough to feed high production dairy cows and heirs selected for replacements. The analysis of the relative feed value proved that no matter from which cut, the biomass ofDactylis glornerata belonged in Ill quality class, （RFV between 103 and 124） and it can be used to feed good beef cattle, older heifers and, in small quantities, dairy cows.展开更多
The solution of Nekrasov’s integral equation is described. By means of this solution the wave kinetic, potential, and full mechanical energies are defined as functions of fluid depth and wavelength. The wave obeys th...The solution of Nekrasov’s integral equation is described. By means of this solution the wave kinetic, potential, and full mechanical energies are defined as functions of fluid depth and wavelength. The wave obeys the laws of mass and energy conservation. It is found that for any constant depth of fluid the wavelength is bounded from above by a value denoted as maximal wavelength. At maximal wavelength 1) the maximum slope of the free surface of the wave exceeds 38o and the value 45o is supposed attainable,2) the wave kinetic energy vanishes. The stability of a steady wave considered as a compound pendulum is analyzed.展开更多
Constitutive equations for melts and concentrated solutions of linear polymers are derived as consequences of dynamics of a separate macromolecule. The model is investigated for viscometric flows. It was shown that th...Constitutive equations for melts and concentrated solutions of linear polymers are derived as consequences of dynamics of a separate macromolecule. The model is investigated for viscometric flows. It was shown that the model gives a good description of non-linear effects of simple shear polymer flows: viscosity anomalies, first and second normal stresses, non-steady shear stresses.展开更多
The structural transformation in thin films of bimetals in the dependence on temperature and concentration of vacancies was investigated. The system Ni-Al structural transformation was realized by computer design acco...The structural transformation in thin films of bimetals in the dependence on temperature and concentration of vacancies was investigated. The system Ni-Al structural transformation was realized by computer design according to the mechanism of self-sustained high(temperature synthesis. Structural transformation is characterized by the presence of dislocations, clusters of point defects and germs of intermetallic phases near interphase boundaries.展开更多
The rapid growth of the global population has resulted in a continuous increase in cropland intensity and a shortening of the fallow period as part of the cropland rotation cycle.Yet,there is a lack of systematic know...The rapid growth of the global population has resulted in a continuous increase in cropland intensity and a shortening of the fallow period as part of the cropland rotation cycle.Yet,there is a lack of systematic knowledge on the extent of fallow lands,particularly in complex landscapes,such as the mountainous regions of China.To fill this knowledge gap,taking Yuanyang County(YYC),Yunnan Province,China,as a case study,we tested a method to identify the spatial-temporal distribution of fallow land by mapping cropland with Landsat data.The overall accuracy of land cover classification,including cropland,ranged between 90.1%and 95.8%from 1998 to 2019.The average accuracy of fallow plots was 75.7%from 2001 to 2019.The annual fallow rate varied between 8.3%and 54.3%,with an average of 20.7%.Kernel density estimated with the probability density function showed that fallow varied between 5 and 13 blocks per km2,gradually decreasing from the central area to the periphery.Increasing elevation,the low value of regional domestic products,and the increased distance to rural settlements were closely related to the higher proportions of fallow land.The approach presented here can be applied to map fallow land in other regions.展开更多
文摘This editorial contains comments on the article“Correlation between preoperative systemic immune inflammation index,nutritional risk index,and prognosis of radical resection of liver cancer”in a recent issue of the World Journal of Gastrointestinal Surgery.It pointed out the actuality and importance of the article and focused primarily on the underlying mechanisms making the systemic immuneinflammation index(SII)and geriatric nutritional risk index(GNRI)prediction features valuable.There are few publications on both SII and GNRI together in hepatocellular carcinoma(HCC)and patient prognosis after radical surgery.Neutrophils release cytokines,chemokines,and enzymes,degrade extracellular matrix,reduce cell adhesion,and create conditions for tumor cell invasion.Neutrophils promote the adhesion of tumor cells to endothelial cells,through physical anchoring.That results in the migration of tumor cells.Pro-angiogenic factors from platelets enhance tumor angiogenesis to meet tumor cell supply needs.Platelets can form a protective film on the surface of tumor cells.This allows avoiding blood flow damage as well as immune system attack.It also induces the epithelial-mesenchymal transformation of tumor cells that is critical for invasiveness.High SII is also associated with macro-and microvascular invasion and increased numbers of circulating tumor cells.A high GNRI was associated with significantly better progression-free and overall survival.HCC patients are a very special population that requires increased attention.SII and GNRI have significant survival prediction value in both palliative treatment and radical surgery settings.The underlying mechanisms of their possible predictive properties lie in the field of essential cancer features.Those features provide tumor nutrition,growth,and distribution throughout the body,such as vascular invasion.On the other hand,they are tied to the possibility of patients to resist tumor progression and development of complications in both postoperative and cancer-related settings.The article is of considerable interest.It would be helpful to continue the study follow-up to 2 years and longer.External validation of the data is needed.
文摘This editorial contains comments on the article“Systematic sequential therapy for ex vivo liver resection and autotransplantation:A case report and review of li-terature”in the recent issue of World Journal of Gastrointestinal Surgery.It points out the actuality and importance of the article and focuses primarily on the role and place of ex vivo liver resection and autotransplantation(ELRAT)and systemic therapy,underlying molecular mechanisms for targeted therapy in perihilar cho-langiocarcinoma(pCCA)management.pCCA is a tough malignancy with a high proportion of advanced disease at the time of diagnosis.The only curative option is radical surgery.Surgical excision and reconstruction become extremely com-plicated and not always could be performed even in localized disease.On the other hand,ELRAT takes its place among surgical options for carefully selected pCCA patients.In advanced disease,systemic therapy becomes a viable option to prolong survival.This editorial describes current possibilities in chemotherapy and reveals underlying mechanisms and projections in targeted therapy with ki-nase inhibitors and immunotherapy in both palliative and adjuvant settings.Fi-broblast grow factor and fibroblast grow factor receptor,human epidermal grow-th factor receptor 2,isocitrate dehydrogenase,and protein kinase cAMP activated catalytic subunit alpha(PRKACA)and beta(PRKACB)pathways have been ac-tively investigated in CCA in last years.Several agents were introduced and approved by the Food and Drug Administration.They all demonstrated mean-ingful activity in CCA patients with no global change in outcomes.That is why every successfully treated patient counts,especially those with advanced disease.In conclusion,pCCA is still hard to treat due to late diagnosis and extremely complicated surgical options.ELRAT also brings some hope,but it could be performed in very carefully selected patients.Advanced disease requires systemic anticancer treatment,which is supposed to be individualized according to the genetic and molecular features of cancer cells.Targeted therapy in combination with chemo-immunotherapy could be effective in susceptible patients.
文摘The dynamics of a bilayer system filling a rectangular cuvette subjected to external heating is studied.The influence of two types of thermal exposure on the flow pattern and on the dynamic contact angle is analyzed.In particular,the cases of local heating from below and distributed thermal load from the lateral walls are considered.The simulation is carried out within the frame of a two-sided evaporative convection model based on the Boussinesq approximation.A benzine–air system is considered as reference system.The variation in time of the contact angle is described for both heating modes.Under lateral heating,near-wall boundary layers emerge together with strong convection,whereas the local thermal load from the lower wall results in the formation of multicellular motion in the entire volume of the fluids and the appearance of transition regimes followed by a steady-state mode.The results of the present study can aid the design of equipment for thermal coating or drying and the development of methods for the formation of patterns with required structure and morphology.
文摘The existing approaches for the design of tourist areas often lead to limited flexibility in project implementation.To realize a more flexible approach,in this study,we formulated a model for planning and designing tourist areas at the local level.Moreover,specific tools for analyzing tourist areas and ensuring sustainable development under changing conditions were developed.This study was conducted in two tourist regions,Biryuzovaya Katun tourist complex and Belokurikha destination(including Belokurikha City with Belokurikha 2 Gornaya tourist complex and surrounding areas),in the Altay Mountains.We employed the recreation opportunity spectrum and proposed a system-integrated programming approach for the design of tourist areas at the destination and site levels.The key of this approach was the collection and analysis of current spatial data,including the spatial distribution of attractions and visitor flows.We constructed heat maps using video recording and unmanned aerial vehicle(UAV)observation data.Moreover,we analyzed the video stream using an image-analyzing framework You Only Look Once(YOLO)v5 software.The heat map of visitor flows based on video recording data in the Andreevskaya Sloboda museum of Belokurikha 2 Gornaya tourist complex allowed us to highlight the most attractive sites in this area and classify them into one of three types:points of functional concentration,points of transitional concentration,and points of attractions.The heat maps in Biryuzovaya Katun tourist complex,created using UAV observation data,allowed us to determine the spatiotemporal patterns of visitor flows and tourists’preferences throughout the day within four time intervals:09:00-12:00,13:00-14:00,14:00-15:00,and 16:00-18:00(LST).The maximum visitor flow density occurred from 16:00 to 18:00 in the beach area of the artificial lake.A comparison between the visitor-concentrated sites and the current facilities provided insights into the demand for attractions and facilities and the lacking areas.Heat maps are useful in analyzing the land use at the site level,while zoning based on the recreation opportunity spectrum can be used to design tourist areas at the destination level.The proposed methods for analyzing the use of tourist areas contribute to the development of adaptive tourism design.
基金Post Graduate Innovation Funding Project of Hebei Province(No.CXZZSS2023041)Hebei Natural Science Foundation of China(No.E2021203138)Special Project for Local Science and Technology Development Guided by the Central Government of Hebei Province(236Z1805G).
文摘In this work,selective laser melting(SLM)process is used to prepare the AlNi6TiZr alloy.By analyzing the printing quality and mechanical properties of the printed specimens with different process parameters,the SLM forming window of AlNi6TiZr is obtained.The relative density of the sample printed with 270 W-1100 mm/s(laser energy density:82 J/mm3)reaches 99.7%,exhibiting excellent mechanical properties(yield strength(YS):421.7 MPa;ultimate tensile strength(UTS):480.4 MPa).After an aging treatment of 325 ℃-12 h,the YS and UTS of the sample increased to 494 MPa and 550.7 MPa,respectively.Adding Ni,Ti,and Zr components promoted the generation of multi-phase precipitates in the Al alloy and improved the synergistic strengthening effect of multi-phases.The hard-shell structure(HSS)formed by the Al_(3)Ni phase at the grain boundary significantly strengthened the grain boundary strength.The precipitated Al_(3)(Ti,Zr)phases at the grain boundaries prevent grain growth and dislocation movement.The Al_(3)Ni and Al_(3)(Ti,Zr)phases have good thermal stability that can still maintain excellent enhancement effects at high temperature.AlNi6TiZr alloy has great application prospects in medium and high-temperature environments.
基金Supported by the National Natural Science Foundation of China, Grant Nos. 30411120111, 30270102, and Russian Foundation for Basic Research, Grant No. 03-04-39026-GFEN_a.
文摘报道了采自新疆阿尔泰山地区的1个中国新记录属假糖芥属Rhammatophyllum O. E. Schulz, 6个中国新记录种——渐尖岩蕨Woodsia acuminata (Fomin) Sipl.、短命繁缕Stellaria alsinoides Boiss. & Buhse、假糖芥Rh. erysimoides (Kar. & Kir.) Al-Shehbaz & O. Appel、克氏鹤虱Lappula krylovii Ovczinnikova, A. I. Pjak & A. L. Ebel、肝色柳穿鱼Linaria hepatica Bunge和佐氏新缬草Valerianella szovitsiana Fisch. & Mey.。
文摘The growing demand for donor organs requires measures to expand donor pool.Those include extended criteria donors, such as elderly people, steatotic livers,donation after cardiac death, etc. Static cold storage to reduce metabolic requirements developed by Collins in late 1960 s is the mainstay and the golden standard for donated organ protection. Hypothermic machine perfusion provides dynamic organ preservation at 4°C with protracted infusion of metabolic substrates to the graft during the ex vivo period. It has been used instead of static cold storage or after it as short perfusion in transplant center. Normothermic machine perfusion(NMP) delivers oxygen, and nutrition at physiological temperature mimicking regular environment in order to support cellular function. This would minimize effects of ischemia/reperfusion injury.Potentially, NMP may help to estimate graft functionality before implantation into a recipient. Clinical studies demonstrated at least its non-inferiority or better outcomes vs static cold storage. Regular grafts donated after brain death could be safely preserved with convenient static cold storage. Except for prolonged ischemia time where hypothermic machine perfusion started in transplant center could be estimated to provide possible positive reconditioning effect. Use of hypothermic machine perfusion in regular donation instead of static cold storage or in extended criteria donors requires further investigation. Multicenter randomized clinical trial supposed to be completed in December 2021. Extended criteria donors need additional measures for graft storage and assessment until its implantation. NMP is actively evaluating promising method for this purpose.Future studies are necessary for precise estimation and confirmation to issue clinical practice recommendations.
基金Project(No.P2518) supported by the Scientific and Research and Educational Staff of Innovative,Russia
文摘The aim of this investigation was to define the effectiveness of non-contact drying using ultrasonic vibrations. Disk radiators were used for carrying out experiments, and a special drying chamber was designed to provide resonant amplification of ultrasonic vibrations (from 130 to 150 dB). Drying of ginseng and other vegetables demonstrated that the application of ultrasonic vibrations reduced power inputs by 20% in comparison with convective drying. It also led to a decrease of 6% in final moisture content, if the duration of drying was constant. The level of intensification of ultrasonic drying was high (up to 50 g for 1 kg of drying material), which helped to lower the temperature of the drying agent and improve the quality of the dried products.
基金Project(51775481)supported by the National Natural Science Foundation of ChinaProject(E2019203418)supported by the Natural Science Foundation of Hebei Province,China。
文摘The selective laser melting(SLM)processed aluminum alloys have already aroused researchers’attention in aerospace,rail transport and petrochemical engineering due to the comprehensive advantages of low density,good corrosion resistance and high mechanical performance.In this paper,an Al-14.1Mg-0.47Si-0.31Sc-0.17Zr alloy was fabricated via SLM.The characteristics of single track at different process parameters,and the influence of hatch spacing on densification,microstructural features and tensile properties of block specimens were systematically studied.The hatch spacing has an influence on the overlap ratio of single track,and further affects the internal forming quality of printed specimen.At a laser power of 160 W and scanning speed of 400 mm/s,the densification of block specimen increased first and then decreased with the increase of hatch spacing.The nearly full dense specimen(98.7%)with a tensile strength of 452 MPa was fabricated at a hatch spacing of 80μm.Typical characteristics of dimple and cleavage on the tensile fracture of the AlMgSiScZr alloy showed the mixed fracture of ductility and brittleness.
基金supported by Program for Basic Scientific Research of the State Academies of Sciences for 2013e2020the RF Ministry of Education and Science (Contract No. 02.G25.31.0063)
文摘The paper proposes an experimental method of material inspection,which is based on digital processing of multi-frequency eddy current measurement data.The influences of various factors(conductivity,the gap between the sample surface and the sensor,the thickness of the sample) on the obtained hodographs are examined by taking the aluminum alloys for example,and the possibility of separation of various factors is analyzed.The results obtained are indicative of how much promise the proposed method offers for the inspection and testing of products made of aluminum alloys.
基金supported by the Russian Foundation for Basic Research (Grant Nos.03-04-39026 and 07-04-90839)the National Natural Science Foundation of China (Grant No. 30411120111)the National Geographic Foundation of USA (GrantNo. 8204-07)
文摘A critical revision of the collections of Brassicaceae in some Chinese （PE, XJA, XJBI, XJFA, XJNM, XJU） and foreign （LE, P） herbaria is made. One genus, Neurotropis （DC.） E K. Mey., and 11 species, Alyssum szarabiacum Nyar., Barbarea stricta Andrz., Erysimum czernjajevii N. Busch, Erysimum kotuchovii D. German, Erysimum mongolicum D. German, Lepidium karelinianum Al-Shehbaz, Matthiola superba Conti, Neurotropis platycarpa （Fisch. ＆ Mey.） E K. Mey., Ptilotrichum dahuricum Peschkova, Sisymbrium subspinescens Bunge, and Smelowskia micrantha （Botsch. ＆ Vved.） Al-Shehbaz ＆ S. I. Warwick, are reported from China for the first time. Six species, Aphragmus involucratus （Bunge） O. E. Schulz, Dontostemonperennis C. A. Mey., Goldbachia torulosa DC., Lepidium amplexicaule Willd., Neotorularia brevipes （Kar. ＆ Kir.） Hedge ＆ J. Leonard, and Parrya stenocarpa Kar. ＆ Kir., are confirmed to occurr in China. Five species, Dontostemon integrifolius （L.） C. A. Mey., Draba zangbeiensis L. L. Lou, Lepidium alashanicum H. L. Yang, Sinapis arvensis L., and Strigosella brevipes （Bunge） Botsch., are reported as novelties for some provinces in China, and Strigosella hispida （Litv.） Botsch. occurs in Xinjiang, China. However, the occurrence of one genus, Pseudoarabidopsis Al-Shehbaz, O＇Kane ＆ Price, and four species, Draba huetii Boiss., Eutrema halophilum （C. A. Mey.） Al-Shehbaz ＆ S. I. Warwick, Galitzkya spathulata （Steph. ex Willd.） V. Bocz., and Pseudoarabidopsis toxophylla （Bieb.） Al-Shehbaz, O＇Kane ＆ Price, could not be confirmed in China. The occurrence of six species, Aphragmus bouffordii Al-Shehbaz, Barbarea orthoceras Ledeb., Lepidium latifolium L., Ptilotrichum canescens （DC.） C. A. Mey., Strigosella hispida （Litv.） Botsch., and Strigosella scorpioides （Bunge） Botsch., is not confirmed in certain provinces of China. All names follow the latest taxonomic treatment for relevant groups; detailed morphological descriptions of the newly recorded taxa are provided; and distinguishing characters from related species already known in China are discussed. Other comments are provided where needed.
文摘The aim of this paper is to analyze fluctuation in nutritional value of Dactylis glomerata and Festuca pratensis varieties grown on mineral and organic soil. Moreover, the paper deals with analysis of their nutritional value in terms of animal feeding. This paper has drawn on two field experiments set up and carried out between 2010 and 2013 by the Research Centre for Cultivar Testing in Slupia Wielka. The experiment was conducted in two experimental stations： one in the Research Centre for Cultivar Testing in Krzyzewo and the other in the Experimental Stations for Variety Testing in Uhinin, being a branch of the Research Centre for Cultivar Testing in Cicibor Duzy. The experiment was arranged and conducted according to COBORU guidelines. The experimental plots were sown with varieties of Dactylis glornerata： Niva, Tukan, Amila, Crown Royale and with varieties of Festuca pratensis： Limosa, Pasja, Anturka, Amelka （d. AND 1009）. In the experimental plots with the varieties of Dactylis glornerata the grass was harvested six times a year and chemical analysis of the biomass was done taking dry matter only from five cuts. The varieties of Festuca pratensis were harvested four times. The RFV （relative feed value） was determined using the Linn and Martin method. Linn and Martin＇s test proved that Festuca pratensis had better nutritional value than Dactylis glomerata. For Dactylis glomerata, no matter what the variety and location was, the relative feed value ranged from 125 to 151, which puts that grass species in II quality class, good enough to feed high production dairy cows and heirs selected for replacements. The analysis of the relative feed value proved that no matter from which cut, the biomass ofDactylis glornerata belonged in Ill quality class, （RFV between 103 and 124） and it can be used to feed good beef cattle, older heifers and, in small quantities, dairy cows.
文摘The solution of Nekrasov’s integral equation is described. By means of this solution the wave kinetic, potential, and full mechanical energies are defined as functions of fluid depth and wavelength. The wave obeys the laws of mass and energy conservation. It is found that for any constant depth of fluid the wavelength is bounded from above by a value denoted as maximal wavelength. At maximal wavelength 1) the maximum slope of the free surface of the wave exceeds 38o and the value 45o is supposed attainable,2) the wave kinetic energy vanishes. The stability of a steady wave considered as a compound pendulum is analyzed.
文摘Constitutive equations for melts and concentrated solutions of linear polymers are derived as consequences of dynamics of a separate macromolecule. The model is investigated for viscometric flows. It was shown that the model gives a good description of non-linear effects of simple shear polymer flows: viscosity anomalies, first and second normal stresses, non-steady shear stresses.
文摘The structural transformation in thin films of bimetals in the dependence on temperature and concentration of vacancies was investigated. The system Ni-Al structural transformation was realized by computer design according to the mechanism of self-sustained high(temperature synthesis. Structural transformation is characterized by the presence of dislocations, clusters of point defects and germs of intermetallic phases near interphase boundaries.
基金supported by the National Natural Science Foundation of China[grant number 42071233]the Strategic Priority Research Program of Chinese Academy of Sciences[grant number XDA20040201]and the Second Tibetan Plateau Scientific Expedition and Research Program[grant number 2019QZKK0603].
文摘The rapid growth of the global population has resulted in a continuous increase in cropland intensity and a shortening of the fallow period as part of the cropland rotation cycle.Yet,there is a lack of systematic knowledge on the extent of fallow lands,particularly in complex landscapes,such as the mountainous regions of China.To fill this knowledge gap,taking Yuanyang County(YYC),Yunnan Province,China,as a case study,we tested a method to identify the spatial-temporal distribution of fallow land by mapping cropland with Landsat data.The overall accuracy of land cover classification,including cropland,ranged between 90.1%and 95.8%from 1998 to 2019.The average accuracy of fallow plots was 75.7%from 2001 to 2019.The annual fallow rate varied between 8.3%and 54.3%,with an average of 20.7%.Kernel density estimated with the probability density function showed that fallow varied between 5 and 13 blocks per km2,gradually decreasing from the central area to the periphery.Increasing elevation,the low value of regional domestic products,and the increased distance to rural settlements were closely related to the higher proportions of fallow land.The approach presented here can be applied to map fallow land in other regions.
