Due to the acceleration of urbanization,the municipal waste(MW)problem has transformed into a global challenge for urb-an sustainability.To elucidate historical trends,current focal points,and future directions in MW ...Due to the acceleration of urbanization,the municipal waste(MW)problem has transformed into a global challenge for urb-an sustainability.To elucidate historical trends,current focal points,and future directions in MW research,we conducted a bibliometric analysis and employed knowledge graph visualization to scrutinize a total of 34212 articles,which were published between 1991 and 2021 in the Web of Science(WoS)core database.The results indicated that current major research themes encompass waste classifica-tion and recycling,waste management and public behavior,waste disposal methods and technologies,as well as environmental impact and evaluation.There has been a shift in the research focus from the environmental impacts of waste incineration to sustainable manage-ment related issues.A comparison of research from six typical countries revealed the differences in research priorities and techniques advantages.Scholars from the USA and Britain initiated MW research earlier than other countries and investigated management issues in depth,such as public behavior and willingness to pay.Meanwhile,Japanese,German,and Swedish scholars conducted extensive studies on advanced waste treatment technologies,such as disposal and recycling,risk assessment,and waste-to-energy techniques.Chinese scholars placed particular emphasis on end-of-pipe treatments and their associated environmental impacts.Hotspots and poten-tial future frontiers were identified by burst detection analysis.Keywords with high value of burst index(BI)worldwide are food waste and circular economy.Chinese scholars have put great efforts on waste environmental impact and its recycling technologies,while we’re expecting to further investigating vulnerable population.Furthermore,this study contributes to bridging the regional gap of scientific research among different countries and fostering international collaboration.展开更多
There is great controversy regarding the origin and source of natural gas in the Lower Triassic Feix-ianguan Formation in the Eastern Sichuan Basin.This seriously restricts the study of natural gas dy-namics in the Fe...There is great controversy regarding the origin and source of natural gas in the Lower Triassic Feix-ianguan Formation in the Eastern Sichuan Basin.This seriously restricts the study of natural gas dy-namics in the Feixianguan Formation and thus hampers natural gas exploration in the region,so further study is urgently required.Using experimental tests of natural gas composition,stable isotopes,and noble gas isotopes with gas chromatography(GC)and mass spectrometry(MS)studies of source rock and reservoir asphalt saturated hydrocarbons,the natural gas geochemical characteristics,the genetic identification and a gas-source comparison of the Feixianguan Formation were studied.Then,con-strained by the thermal history,the histories of gas generation and expulsion were restored by basin simulation technology.Finally,a gas accumulation model was established for the Feixianguan Formation.The results showed that(1)the H_(2)S-rich and H2S-poor gas reservoirs of the Feixianguan Formation are distributed on the east and west sides of the Kaijiang-Liangping trough in the Eastern Sichuan Basin,respectively.The carbon and hydrogen isotope compositions of the natural gas in the gas reservoirs are generally heavy and have typical characteristics of high-maturity dry gas reservoirs.(2)The natural gas of the Feixianguan Formation is organic thermogenic gas,which is mainly oil-type gas generated by the secondary cracking of crude oil.The gas-generating parent material is mainly type II kerogen.(3)The natural gas of the Feixianguan Formation in the Eastern Sichuan Basin was mainly generated by argil-laceous source rocks of the Upper Permian Longtan Formation.(4)Natural gas accumulation occurred as follows:the paleo-structure heights were filled with crude oil in the Early Jurassic,and paleo-oil res-ervoirs were formed in the Feixianguan Formation;during the Middle-Late Jurassic,the paleo-oil res-ervoirs were cracked when the reservoir temperatures rose above 160 C,and paleo-gas reservoirs were formed.Since the end of the Late Jurassic,the paleo-gas reservoirs have been adjusted and reformed to form the present-day natural gas reservoirs.These results provide a basis for studying natural gas accumulation dynamics of the Feixianguan Formation in the Eastern Sichuan Basin.展开更多
The current and dominant theory about the origin of modern humans is the out-of-Africa hypothesis, which asserts that populations of Homo sapiens left Africa 100,000 years ago and replaced indigenous populations of hu...The current and dominant theory about the origin of modern humans is the out-of-Africa hypothesis, which asserts that populations of Homo sapiens left Africa 100,000 years ago and replaced indigenous populations of humans in Eurasia. Many scholars equated the out-of-Africa dispersal of humans with paleoenvironmental changes. However, until now, few have paid special attention to the faunal data and whether or not faunal patterns are supportive of the popular theory. Recent comparative study of the Chinese fauna shows that the communication of faunas between Africa and East Asia could have occurred during the Neogene, but it was very limited during the Pleistocene. In the Chinese Quaternary fauna, only 16% of the genera are also present in the sub-Saharan African fauna. There is also no element among the dominant taxa of the Chinese Quaternary fauna which can be related to the African fauna. There is no reliable proof for the existence of Hippopotamus and Giraffa, as well as Panthera leo, during the Quaternary in China. Two controversial taxa are Acinonyx and Crocuta, about which there is still argument concerning their species identification in Eurasia. It is possible that both of the genera have co-specific taxa in Africa and Eurasia. Although the two genera are confined to Africa today, they did have a long evolutionary history in China. For the Out of Africa hypothesis for Homo sapiens, the implications of the limited faunal interchanges between China and Africa are not completely clear yet.展开更多
1 Introduction Dolomite[Ca Mg(CO3)2],a common mineral in carbonate rocks,can be found in various geological settings from Precambrian to modern age,and is widely reported in almost all sedimentary and digenetic
How to determine accurately the association states of solutes in aqueous systems is of fundamental importance in a variety of chemical, physical, and biological processes, We apply four widely used criteria to analyze...How to determine accurately the association states of solutes in aqueous systems is of fundamental importance in a variety of chemical, physical, and biological processes, We apply four widely used criteria to analyze the dynamic association processes of solutes, e.g., amphiphilic molecules, and to find the inappropriate selections of representative sites on solutes in these criteria may bring about appreciable influence on the estimation of dynamic association behaviors such as unrealistic packing radii and even misleading packing structures. It would be better to select dynamically representative sites on solute molecules based on the characteristic of solute associations. Our detailed discussions give a guide on how to determine an appropriate criterion to accurately analyze the association behaviors of solute molecules in aqueous solutions.展开更多
Inductive energy storage systems (IES)require opening switches which are technically much more difficult to realize than closing switches. Institute of Advanced Technology ( IAT ) puts forward a meat grinder with ...Inductive energy storage systems (IES)require opening switches which are technically much more difficult to realize than closing switches. Institute of Advanced Technology ( IAT ) puts forward a meat grinder with an inductive pulse power topology called slow transfer of energy through capacitive hybrid (STRETCH). In this topology, an integrated gate-commutated thyristor (IGCT) is capable of breaking the charging currents on the order of 4 kA, and it may encounter difficulties in expanding to higher energy systems. German-French Institute of Saint Louis (ISL) has developed a high-power opening switch based on standard high-power thyristors by using their so-called inverse current commutation with semiconductor devices (ICCOS) countercurrent commutation principle. Two topologies of the STRETCH meat grinder with ICCOS are analyzed. And they are compared based on the voltage across the main switch, the current multiplication factor and other aspects by u- sing Matlab simulations. The advantages and disadvantages of the two topologies are shown through the comparisons. Therefore a more suitable topology can be chosen for realistic applications accord- ing to their performances.展开更多
In this paper, we first discuss the methods of comparing two special absolutely convergentsine series, sinnx and sinnx. We state the theorem in.one dimensional case as follows; Theorem. Let be convergent series with n...In this paper, we first discuss the methods of comparing two special absolutely convergentsine series, sinnx and sinnx. We state the theorem in.one dimensional case as follows; Theorem. Let be convergent series with nonnegative terms. SupposeThen for all x∈[0,π]If, in addition, then展开更多
A“simplified”figure was proposed in 2011 to summarize the results of controlled trials that evaluate different treatments aimed at the same disease condition.The original criteria for classifying individual binary c...A“simplified”figure was proposed in 2011 to summarize the results of controlled trials that evaluate different treatments aimed at the same disease condition.The original criteria for classifying individual binary comparisons included superiority,inferiority and no significance difference;hence,they did not differentiate between no proof of difference vs proof of no difference.We updated the criteria employed in the original“simplified”figure in order to include this differentiation.A revised version of the simplified figure is proposed and described herein.An example of application is also presented.The example is focused on first-line treatments for paroxysmal atrial fibrillation.Three treatments(medical therapy,cryoballoon ablation,radiofrequency ablation)are compared with one another through direct and indirect comparisons.展开更多
Objective:An increasing number of studies indicate that autophagy plays an important role in the pathogenesis of spinal cord injury,and that regulating autophagy can enhance recovery from spinal cord injury.However,th...Objective:An increasing number of studies indicate that autophagy plays an important role in the pathogenesis of spinal cord injury,and that regulating autophagy can enhance recovery from spinal cord injury.However,the effect of regulating autophagy and whether autophagy is detrimental or beneficial after spinal cord injury remain unclear.Therefore,in this study we evaluated the effects of autophagy regulation on spinal cord injury in rats by direct and indirect comparison,in an effort to provide a basis for further research.Data source:Relevant literature published from inception to February 1,2018 were included by searching Wanfang,CNKI,Web of Science,MEDLINE(OvidSP),PubMed and Google Scholar in English and Chinese.The keywords included"autophagy","spinal cord injury",and"rat".Data selection:The literature included in vivo experimental studies on autophagy regulation in the treatment of spinal cord injury(including intervention pre-and post-spinal cord injury).Meta-analyses were conducted at different time points to compare the therapeutic effects of promoting or inhibiting autophagy,and subgroup analyses were also conducted.Outcome measure:Basso,Beattie,and Bresnahan scores.Results:Of the 622 studies,33 studies of median quality were included in the analyses.Basso,Beattie,and Bresnahan scores were higher at 1 day(MD=1.80,95%CI:0.81-2.79,P=0.0004),3 days(MD=0.92,95%CI:0.72-1.13,P<0.00001),1 week(MD=2.39,95%CI:1.85-2.92,P<0.00001),2 weeks(MD=3.26,95%CI:2.40-4.13,P<0.00001),3 weeks(MD=3.13,95%CI:2.51-3.75,P<0.00001)and 4 weeks(MD=3.18,95%CI:2.43-3.92,P<0.00001)after spinal cord injury with upregulation of autophagy compared with the control group(drug solvent control,such as saline group).Basso,Beattie,and Bresnahan scores were higher at 1 day(MD=6.48,95%CI:5.83-7.13,P<0.00001),2 weeks(MD=2.43,95%CI:0.79-4.07,P=0.004),3 weeks(MD=2.96,95%CI:0.09-5.84,P=0.04)and 4 weeks(MD=4.41,95%CI:1.08-7.75,P=0.01)after spinal cord injury with downregulation of autophagy compared with the control group.Indirect comparison of upregulation and downregulation of autophagy showed no differences in Basso,Beattie,and Bresnahan scores at 1 day(MD=-4.68,95%CI:-5.840 to-3.496,P=0.94644),3 days(MD=-0.28,95%CI:-2.231-1.671,P=0.99448),1 week(MD=1.83,95%CI:0.0076-3.584,P=0.94588),2 weeks(MD=0.81,95%CI:-0.850-2.470,P=0.93055),3 weeks(MD=0.17,95%Cl:-2.771-3.111,P=0.99546)or 4 weeks(MD=-1.23,95%Cl:-4.647-2.187,P=0.98264)compared with the control group.Conclusion:Regulation of autophagy improves neurological function,whether it is upregulated or downregulated.There was no difference between upregulation and downregulation of autophagy in the treatment of spinal cord injury.The variability in results among the studies may be associated with differences in research methods,the lack of clearly defined autophagy characteristics after spinal cord injury,and the limited autophagy monitoring techniques.Thus,methods should be standardized,and the dynamic regulation of autophagy should be examined in future studies.展开更多
Atmospheric CO_(2)is one of key parameters to estimate air-sea CO_(2)flux.The Orbiting Carbon Observatory-2(OCO-2)satellite has observed the column-averaged dry-air mole fractions of global atmospheric carbon dioxide(...Atmospheric CO_(2)is one of key parameters to estimate air-sea CO_(2)flux.The Orbiting Carbon Observatory-2(OCO-2)satellite has observed the column-averaged dry-air mole fractions of global atmospheric carbon dioxide(XCO_(2))since 2014.In this study,the OCO-2 XCO_(2)products were compared between in-situ data from the Total Carbon Column Network(TCCON)and Global Monitoring Division(GMD),and modeling data from CarbonTracker2019 over global ocean and land.Results showed that the OCO-2 XCO_(2)data are consistent with the TCCON and GMD in situ XCO_(2)data,with mean absolute biases of 0.25×10^(-6)and 0.67×10^(-6),respectively.Moreover,the OCO-2 XCO_(2)data are also consistent with the CarbonTracker2019 modeling XCO_(2)data,with mean absolute biases of 0.78×10^(-6)over ocean and 1.02×10^(-6)over land.The results indicated the high accuracy of the OCO-2 XCO_(2)product over global ocean which could be applied to estimate the air-sea CO_(2)flux.展开更多
The paper gives a brief description about the current main forest fire danger rating systems in the world, which in- clude forest fire danger rating system used in Canada, USA, Australia, and other countries. It show...The paper gives a brief description about the current main forest fire danger rating systems in the world, which in- clude forest fire danger rating system used in Canada, USA, Australia, and other countries. It shows the composition, structure and development of the main fire danger rating systems. The limitations of those systems are also discussed. Through a comparison of the three main forest fire danger rating systems the paper describes their differences on development, fuel complex descriptions, inputs and outputs, and their applications and finds that the technologies of the Canadian forest fire danger rating system can be adopted for China to develop a national forest fire danger rating system. Two steps are needed to develop our own national forest fire danger rating system. Firstly, we apply the CFFDRS directly. Then some studies should be done to calibrate the FDRS to local weather and fuel characteristics.展开更多
The Chinese Zhongshan Station in Antarctica and the stations in Svalbard (Auroral station at Longyearbyen and NP station at Ny lesund) are closely magnetic conjugate. All of them are equipped similar measurement inst...The Chinese Zhongshan Station in Antarctica and the stations in Svalbard (Auroral station at Longyearbyen and NP station at Ny lesund) are closely magnetic conjugate. All of them are equipped similar measurement instruments dealing with upper atmospheric physics. Therefore, there is a good reason to conduct a cooperative research program between China and Norway to do the inter hemispheric comparisons of geospace environment in the polar regions. It will make significant contribution to further understanding of the coupled magnetosphere ionsphere system. The scientific aims of the cooperative project are: to experimentally verify the modeled complicated conjugate relationship between Zhongshan Station in the Antarctic and Svalbard in the Arctic. To derive knowledge from the conjugate characteristics of auroral formations, ionospheric features and space plasma waves in the polar regions, which in turn will lead to better understanding of the solar wind magnetosphere ionosphere coupling processes. The proposed research contents, research methods and experimental techniques are discussed, and the manners of the cooperative research are suggested in the paper.展开更多
Alxa,located at the junction of the North China plate and the Tarim plate,is characterized by complicated geological conditions and obvious climate changes.Unique geological and geographic conditions formed a variety ...Alxa,located at the junction of the North China plate and the Tarim plate,is characterized by complicated geological conditions and obvious climate changes.Unique geological and geographic conditions formed a variety of landscapes in Alxa, including desert landscape,Gobi landscape,wind -erosion landform,canyon landform,etc.This paper compares and evaluates the scientific interests展开更多
Comparisons of particle’s thermal behavior between Fe base alloy and boron carbide in plasma transferred arc (PTA) space was made based on theoretical evaluation results in this article. It was found that most of t...Comparisons of particle’s thermal behavior between Fe base alloy and boron carbide in plasma transferred arc (PTA) space was made based on theoretical evaluation results in this article. It was found that most of the Fe base particles would be fully melted while they transporting through the central plasma field with 200 A surfacing currents. And the particles with a diameter less than 0.5×10 -4 m might be fully evaporated. However, for the boron carbide (B 4C) particles, only the one with a diameter less than 0.5×10 -4 m could be melted in the same PTA space. Most of B 4C particles are only preheated at its solid state when they were fed through the central field of PTA plasma when the surfacing current is equal to or less than 200 A . When the arc current was smaller than100 A , only the particles smaller than 0.5×10 -4 m could be melted in the PTA space for the Fe base alloy. Almost none of the discussed B 4C particles could be melted in the 100 A PTA space.展开更多
We apply the Colour Family Drawing Test, as a development of the traditional black and white test, for cross-cultural comparison. The participants, aged 7 - 10 years, both genders, were examined individually. Each sub...We apply the Colour Family Drawing Test, as a development of the traditional black and white test, for cross-cultural comparison. The participants, aged 7 - 10 years, both genders, were examined individually. Each subject sat at a single table with a white rectangular card of standard size, 24 well-sharpened colour pencils, a black pencil, an eraser and other appropriate tools. S/he received this verbal instruction: “Draw your family”. The procedure was firstly applied to 120 participants attending primary schools of Rome (Biasi, Bonaiuto and Levin, 2014). The families were evaluated through a semi-structural interview conducted with the children’s teachers and divided into: Harmonious versus Very Conflictual Families. The drawings made by children of Harmonious Families consistently used “Reassuring and Playful Colours” (Pink, Orange, Sky Blue, Light Green, Light Yellow, other pastel colours);and were larger, tidier and more proportioned to respect the opposite group. Children belonging to Conflictual Families used mostly “Alarming and Serious Colours” (Grey, Black, Dark Bleu, Violet, Olive Green) and their drawings were less extended, more often disordered and had typical deformations such as figures too thin. A second investigation examined 120 participants belonging to Asian immigrant families residing in Italy. A third investigation examined 120 participants belonging to Russian families of Moscow. Both last two investigations obtained very similar results on the use of colours, and gave a confirmation of the relevance of the Colour Family Drawing Test.展开更多
Acupuncture therapy had established in China and it distributed among Asian countries and developed in each country as traditional medicine. In this project we compared the procedures and effects of traditional acupun...Acupuncture therapy had established in China and it distributed among Asian countries and developed in each country as traditional medicine. In this project we compared the procedures and effects of traditional acupuncture therapies in China, Korea and Japan by using 10 healthy young male volunteers with written informed consent. Total white cell counts, leukocyte subsets and noradrenalin contents were used as outcomes. Three well trained traditional acupuncture therapists were chosen and they treated the same subjects at random order with intervals of at least two months. Each acupuncturist made his diagnosis and points selection for potentiate vital conditions. Clearly different procedures and point selections were used among three traditional acupuncture therapies on the same subject and the obtained changes of outcome measures also differed. Although variations of data were quite large, these results clearly demonstrated that acupuncture therapies have developed among three countries in unique manner.展开更多
Land use/cover change is an important parameter in the climate and ecological simulations. Although they had been widely used in the community, SAGE dataset and HYDE dataset, the two representative global historical l...Land use/cover change is an important parameter in the climate and ecological simulations. Although they had been widely used in the community, SAGE dataset and HYDE dataset, the two representative global historical land use datasets, were little assessed about their accuracies in regional scale. Here, we carried out some assessments for the traditional cultivated region of China (TCRC) over last 300 years, by comparing SAGE2010 and HYDE (v3.1) with Chinese Historical Cropland Dataset (CHCD). The comparisons were performed at three spatial scales: entire study area, provincial area and 60 km by 60 km grid cell. The results show that (1) the cropland area from SAGE2010 was much more than that from CHCD moreover, the growth at a rate of 0.51% from 1700 to 1950 and -0.34% after 1950 were also inconsistent with that from CHCD. (2) HYDE dataset (v3.1) was closer to CHCD dataset than SAGE dataset on entire study area. However, the large biases could be detected at provincial scale and 60 km by 60 km grid cell scale. The percent of grid cells having biases greater than 70% (〈-70% or 〉70%) and 90% (〈-90% or 〉90%) accounted for 56%-63% and 40%-45% of the total grid cells respectively while those having biases range from -10% to 10% and from -30% to 30% account for only 5%-6% and 17% of the total grid cells respectively. (3) Using local historical archives to reconstruct historical dataset with high accuracy would be a valu- able way to improve the accuracy of climate and ecological simulation.展开更多
One-class support vector machines (one-class SVMs) are powerful tools that are widely used in many applications. This paper describes a semi-supervised one-class SVM that uses supervision in terms of relative compar...One-class support vector machines (one-class SVMs) are powerful tools that are widely used in many applications. This paper describes a semi-supervised one-class SVM that uses supervision in terms of relative comparisons. The analysis uses a hypersphere version of one-class SVMs with a penalty term appended to the objective function. The method simultaneously finds the minimum sphere in the feature space that encloses most of the target points and considers the relative comparisons. The result is a standard convex quadratic programming problem, which can be solved by adapting standard methods for SVM training, i.e., sequential minimal optimization. This one-class SVM can be applied to semi-supervised clustering and multi-classification problems. Tests show that this method achieves higher accuracy and better generalization performance than previous SVMs.展开更多
基金Under the auspices of the General Program of National Natural Science Foundation of China(No.42271112)General Research Project of Beijing Municipal Commission of Education Science(No.KM202011417008)。
文摘Due to the acceleration of urbanization,the municipal waste(MW)problem has transformed into a global challenge for urb-an sustainability.To elucidate historical trends,current focal points,and future directions in MW research,we conducted a bibliometric analysis and employed knowledge graph visualization to scrutinize a total of 34212 articles,which were published between 1991 and 2021 in the Web of Science(WoS)core database.The results indicated that current major research themes encompass waste classifica-tion and recycling,waste management and public behavior,waste disposal methods and technologies,as well as environmental impact and evaluation.There has been a shift in the research focus from the environmental impacts of waste incineration to sustainable manage-ment related issues.A comparison of research from six typical countries revealed the differences in research priorities and techniques advantages.Scholars from the USA and Britain initiated MW research earlier than other countries and investigated management issues in depth,such as public behavior and willingness to pay.Meanwhile,Japanese,German,and Swedish scholars conducted extensive studies on advanced waste treatment technologies,such as disposal and recycling,risk assessment,and waste-to-energy techniques.Chinese scholars placed particular emphasis on end-of-pipe treatments and their associated environmental impacts.Hotspots and poten-tial future frontiers were identified by burst detection analysis.Keywords with high value of burst index(BI)worldwide are food waste and circular economy.Chinese scholars have put great efforts on waste environmental impact and its recycling technologies,while we’re expecting to further investigating vulnerable population.Furthermore,this study contributes to bridging the regional gap of scientific research among different countries and fostering international collaboration.
基金supported by the National Natural Science Foundation of China(Grant No.41972109)the Chengdu University of Technology Postgraduate Innovative Cultivation Program(CDUT2022BJCX004).
文摘There is great controversy regarding the origin and source of natural gas in the Lower Triassic Feix-ianguan Formation in the Eastern Sichuan Basin.This seriously restricts the study of natural gas dy-namics in the Feixianguan Formation and thus hampers natural gas exploration in the region,so further study is urgently required.Using experimental tests of natural gas composition,stable isotopes,and noble gas isotopes with gas chromatography(GC)and mass spectrometry(MS)studies of source rock and reservoir asphalt saturated hydrocarbons,the natural gas geochemical characteristics,the genetic identification and a gas-source comparison of the Feixianguan Formation were studied.Then,con-strained by the thermal history,the histories of gas generation and expulsion were restored by basin simulation technology.Finally,a gas accumulation model was established for the Feixianguan Formation.The results showed that(1)the H_(2)S-rich and H2S-poor gas reservoirs of the Feixianguan Formation are distributed on the east and west sides of the Kaijiang-Liangping trough in the Eastern Sichuan Basin,respectively.The carbon and hydrogen isotope compositions of the natural gas in the gas reservoirs are generally heavy and have typical characteristics of high-maturity dry gas reservoirs.(2)The natural gas of the Feixianguan Formation is organic thermogenic gas,which is mainly oil-type gas generated by the secondary cracking of crude oil.The gas-generating parent material is mainly type II kerogen.(3)The natural gas of the Feixianguan Formation in the Eastern Sichuan Basin was mainly generated by argil-laceous source rocks of the Upper Permian Longtan Formation.(4)Natural gas accumulation occurred as follows:the paleo-structure heights were filled with crude oil in the Early Jurassic,and paleo-oil res-ervoirs were formed in the Feixianguan Formation;during the Middle-Late Jurassic,the paleo-oil res-ervoirs were cracked when the reservoir temperatures rose above 160 C,and paleo-gas reservoirs were formed.Since the end of the Late Jurassic,the paleo-gas reservoirs have been adjusted and reformed to form the present-day natural gas reservoirs.These results provide a basis for studying natural gas accumulation dynamics of the Feixianguan Formation in the Eastern Sichuan Basin.
基金supported by the International Cooperation Program of MST of China(2009DFB20580)the Major Basic Research Project of MST of China(Grant No: 2006CB806400)+1 种基金Special Basic Research Project(Grant No:2007FY110200)of MST of Chinathe IVPP Project(Grant No:KA209508)
文摘The current and dominant theory about the origin of modern humans is the out-of-Africa hypothesis, which asserts that populations of Homo sapiens left Africa 100,000 years ago and replaced indigenous populations of humans in Eurasia. Many scholars equated the out-of-Africa dispersal of humans with paleoenvironmental changes. However, until now, few have paid special attention to the faunal data and whether or not faunal patterns are supportive of the popular theory. Recent comparative study of the Chinese fauna shows that the communication of faunas between Africa and East Asia could have occurred during the Neogene, but it was very limited during the Pleistocene. In the Chinese Quaternary fauna, only 16% of the genera are also present in the sub-Saharan African fauna. There is also no element among the dominant taxa of the Chinese Quaternary fauna which can be related to the African fauna. There is no reliable proof for the existence of Hippopotamus and Giraffa, as well as Panthera leo, during the Quaternary in China. Two controversial taxa are Acinonyx and Crocuta, about which there is still argument concerning their species identification in Eurasia. It is possible that both of the genera have co-specific taxa in Africa and Eurasia. Although the two genera are confined to Africa today, they did have a long evolutionary history in China. For the Out of Africa hypothesis for Homo sapiens, the implications of the limited faunal interchanges between China and Africa are not completely clear yet.
基金financially supported by Natural Science Foundation of China (NSFC, No. 41272115)
文摘1 Introduction Dolomite[Ca Mg(CO3)2],a common mineral in carbonate rocks,can be found in various geological settings from Precambrian to modern age,and is widely reported in almost all sedimentary and digenetic
基金Supported by the National Science Fund for Outstanding Young Scholars under Grant No 11422542the Key Research Program of Chinese Academy of Sciences under Grant No KJZD-EW-M03,KIPCAS+1 种基金the Shanghai Supercomputer Center of Chinathe High Performance Computing Center of Shanghai University
文摘How to determine accurately the association states of solutes in aqueous systems is of fundamental importance in a variety of chemical, physical, and biological processes, We apply four widely used criteria to analyze the dynamic association processes of solutes, e.g., amphiphilic molecules, and to find the inappropriate selections of representative sites on solutes in these criteria may bring about appreciable influence on the estimation of dynamic association behaviors such as unrealistic packing radii and even misleading packing structures. It would be better to select dynamically representative sites on solute molecules based on the characteristic of solute associations. Our detailed discussions give a guide on how to determine an appropriate criterion to accurately analyze the association behaviors of solute molecules in aqueous solutions.
文摘Inductive energy storage systems (IES)require opening switches which are technically much more difficult to realize than closing switches. Institute of Advanced Technology ( IAT ) puts forward a meat grinder with an inductive pulse power topology called slow transfer of energy through capacitive hybrid (STRETCH). In this topology, an integrated gate-commutated thyristor (IGCT) is capable of breaking the charging currents on the order of 4 kA, and it may encounter difficulties in expanding to higher energy systems. German-French Institute of Saint Louis (ISL) has developed a high-power opening switch based on standard high-power thyristors by using their so-called inverse current commutation with semiconductor devices (ICCOS) countercurrent commutation principle. Two topologies of the STRETCH meat grinder with ICCOS are analyzed. And they are compared based on the voltage across the main switch, the current multiplication factor and other aspects by u- sing Matlab simulations. The advantages and disadvantages of the two topologies are shown through the comparisons. Therefore a more suitable topology can be chosen for realistic applications accord- ing to their performances.
文摘In this paper, we first discuss the methods of comparing two special absolutely convergentsine series, sinnx and sinnx. We state the theorem in.one dimensional case as follows; Theorem. Let be convergent series with nonnegative terms. SupposeThen for all x∈[0,π]If, in addition, then
文摘A“simplified”figure was proposed in 2011 to summarize the results of controlled trials that evaluate different treatments aimed at the same disease condition.The original criteria for classifying individual binary comparisons included superiority,inferiority and no significance difference;hence,they did not differentiate between no proof of difference vs proof of no difference.We updated the criteria employed in the original“simplified”figure in order to include this differentiation.A revised version of the simplified figure is proposed and described herein.An example of application is also presented.The example is focused on first-line treatments for paroxysmal atrial fibrillation.Three treatments(medical therapy,cryoballoon ablation,radiofrequency ablation)are compared with one another through direct and indirect comparisons.
基金supported by the Beijing Excellent Talent Training Foundation of China,No.2017000021469G215(to DZhang)the Natural Science Foundation of Capital Medical University of China,No.PYZ2018081(to DZhang)the Youth Science Foundation of Beijing Tiantan Hospital of China,No.2016-YQN-14(to DZhang)
文摘Objective:An increasing number of studies indicate that autophagy plays an important role in the pathogenesis of spinal cord injury,and that regulating autophagy can enhance recovery from spinal cord injury.However,the effect of regulating autophagy and whether autophagy is detrimental or beneficial after spinal cord injury remain unclear.Therefore,in this study we evaluated the effects of autophagy regulation on spinal cord injury in rats by direct and indirect comparison,in an effort to provide a basis for further research.Data source:Relevant literature published from inception to February 1,2018 were included by searching Wanfang,CNKI,Web of Science,MEDLINE(OvidSP),PubMed and Google Scholar in English and Chinese.The keywords included"autophagy","spinal cord injury",and"rat".Data selection:The literature included in vivo experimental studies on autophagy regulation in the treatment of spinal cord injury(including intervention pre-and post-spinal cord injury).Meta-analyses were conducted at different time points to compare the therapeutic effects of promoting or inhibiting autophagy,and subgroup analyses were also conducted.Outcome measure:Basso,Beattie,and Bresnahan scores.Results:Of the 622 studies,33 studies of median quality were included in the analyses.Basso,Beattie,and Bresnahan scores were higher at 1 day(MD=1.80,95%CI:0.81-2.79,P=0.0004),3 days(MD=0.92,95%CI:0.72-1.13,P<0.00001),1 week(MD=2.39,95%CI:1.85-2.92,P<0.00001),2 weeks(MD=3.26,95%CI:2.40-4.13,P<0.00001),3 weeks(MD=3.13,95%CI:2.51-3.75,P<0.00001)and 4 weeks(MD=3.18,95%CI:2.43-3.92,P<0.00001)after spinal cord injury with upregulation of autophagy compared with the control group(drug solvent control,such as saline group).Basso,Beattie,and Bresnahan scores were higher at 1 day(MD=6.48,95%CI:5.83-7.13,P<0.00001),2 weeks(MD=2.43,95%CI:0.79-4.07,P=0.004),3 weeks(MD=2.96,95%CI:0.09-5.84,P=0.04)and 4 weeks(MD=4.41,95%CI:1.08-7.75,P=0.01)after spinal cord injury with downregulation of autophagy compared with the control group.Indirect comparison of upregulation and downregulation of autophagy showed no differences in Basso,Beattie,and Bresnahan scores at 1 day(MD=-4.68,95%CI:-5.840 to-3.496,P=0.94644),3 days(MD=-0.28,95%CI:-2.231-1.671,P=0.99448),1 week(MD=1.83,95%CI:0.0076-3.584,P=0.94588),2 weeks(MD=0.81,95%CI:-0.850-2.470,P=0.93055),3 weeks(MD=0.17,95%Cl:-2.771-3.111,P=0.99546)or 4 weeks(MD=-1.23,95%Cl:-4.647-2.187,P=0.98264)compared with the control group.Conclusion:Regulation of autophagy improves neurological function,whether it is upregulated or downregulated.There was no difference between upregulation and downregulation of autophagy in the treatment of spinal cord injury.The variability in results among the studies may be associated with differences in research methods,the lack of clearly defined autophagy characteristics after spinal cord injury,and the limited autophagy monitoring techniques.Thus,methods should be standardized,and the dynamic regulation of autophagy should be examined in future studies.
基金The National Key Research and Development Programme of China under contract No.2017YFA0603004the Fund of Southern Marine Science and Engineering Guangdong Laboratory(Zhanjiang)(Zhanjiang Bay Laboratory)under contract No.ZJW-2019-08+1 种基金the National Natural Science Foundation of China under contract Nos 41825014,41676172 and 41676170the Global Change and Air-Sea Interaction Project of China under contract Nos GASI-02-SCS-YGST2-01,GASI-02-PACYGST2-01 and GASI-02-IND-YGST2-01。
文摘Atmospheric CO_(2)is one of key parameters to estimate air-sea CO_(2)flux.The Orbiting Carbon Observatory-2(OCO-2)satellite has observed the column-averaged dry-air mole fractions of global atmospheric carbon dioxide(XCO_(2))since 2014.In this study,the OCO-2 XCO_(2)products were compared between in-situ data from the Total Carbon Column Network(TCCON)and Global Monitoring Division(GMD),and modeling data from CarbonTracker2019 over global ocean and land.Results showed that the OCO-2 XCO_(2)data are consistent with the TCCON and GMD in situ XCO_(2)data,with mean absolute biases of 0.25×10^(-6)and 0.67×10^(-6),respectively.Moreover,the OCO-2 XCO_(2)data are also consistent with the CarbonTracker2019 modeling XCO_(2)data,with mean absolute biases of 0.78×10^(-6)over ocean and 1.02×10^(-6)over land.The results indicated the high accuracy of the OCO-2 XCO_(2)product over global ocean which could be applied to estimate the air-sea CO_(2)flux.
基金Supported by the Beijing Fund of Natural Science (Grant No. 6042025),China NKBRSF Project (Grant No. 2001CB409600) and the fund of Forest Protection Laboratory,State Forestry Administration
文摘The paper gives a brief description about the current main forest fire danger rating systems in the world, which in- clude forest fire danger rating system used in Canada, USA, Australia, and other countries. It shows the composition, structure and development of the main fire danger rating systems. The limitations of those systems are also discussed. Through a comparison of the three main forest fire danger rating systems the paper describes their differences on development, fuel complex descriptions, inputs and outputs, and their applications and finds that the technologies of the Canadian forest fire danger rating system can be adopted for China to develop a national forest fire danger rating system. Two steps are needed to develop our own national forest fire danger rating system. Firstly, we apply the CFFDRS directly. Then some studies should be done to calibrate the FDRS to local weather and fuel characteristics.
文摘The Chinese Zhongshan Station in Antarctica and the stations in Svalbard (Auroral station at Longyearbyen and NP station at Ny lesund) are closely magnetic conjugate. All of them are equipped similar measurement instruments dealing with upper atmospheric physics. Therefore, there is a good reason to conduct a cooperative research program between China and Norway to do the inter hemispheric comparisons of geospace environment in the polar regions. It will make significant contribution to further understanding of the coupled magnetosphere ionsphere system. The scientific aims of the cooperative project are: to experimentally verify the modeled complicated conjugate relationship between Zhongshan Station in the Antarctic and Svalbard in the Arctic. To derive knowledge from the conjugate characteristics of auroral formations, ionospheric features and space plasma waves in the polar regions, which in turn will lead to better understanding of the solar wind magnetosphere ionosphere coupling processes. The proposed research contents, research methods and experimental techniques are discussed, and the manners of the cooperative research are suggested in the paper.
文摘Alxa,located at the junction of the North China plate and the Tarim plate,is characterized by complicated geological conditions and obvious climate changes.Unique geological and geographic conditions formed a variety of landscapes in Alxa, including desert landscape,Gobi landscape,wind -erosion landform,canyon landform,etc.This paper compares and evaluates the scientific interests
文摘Comparisons of particle’s thermal behavior between Fe base alloy and boron carbide in plasma transferred arc (PTA) space was made based on theoretical evaluation results in this article. It was found that most of the Fe base particles would be fully melted while they transporting through the central plasma field with 200 A surfacing currents. And the particles with a diameter less than 0.5×10 -4 m might be fully evaporated. However, for the boron carbide (B 4C) particles, only the one with a diameter less than 0.5×10 -4 m could be melted in the same PTA space. Most of B 4C particles are only preheated at its solid state when they were fed through the central field of PTA plasma when the surfacing current is equal to or less than 200 A . When the arc current was smaller than100 A , only the particles smaller than 0.5×10 -4 m could be melted in the PTA space for the Fe base alloy. Almost none of the discussed B 4C particles could be melted in the 100 A PTA space.
文摘We apply the Colour Family Drawing Test, as a development of the traditional black and white test, for cross-cultural comparison. The participants, aged 7 - 10 years, both genders, were examined individually. Each subject sat at a single table with a white rectangular card of standard size, 24 well-sharpened colour pencils, a black pencil, an eraser and other appropriate tools. S/he received this verbal instruction: “Draw your family”. The procedure was firstly applied to 120 participants attending primary schools of Rome (Biasi, Bonaiuto and Levin, 2014). The families were evaluated through a semi-structural interview conducted with the children’s teachers and divided into: Harmonious versus Very Conflictual Families. The drawings made by children of Harmonious Families consistently used “Reassuring and Playful Colours” (Pink, Orange, Sky Blue, Light Green, Light Yellow, other pastel colours);and were larger, tidier and more proportioned to respect the opposite group. Children belonging to Conflictual Families used mostly “Alarming and Serious Colours” (Grey, Black, Dark Bleu, Violet, Olive Green) and their drawings were less extended, more often disordered and had typical deformations such as figures too thin. A second investigation examined 120 participants belonging to Asian immigrant families residing in Italy. A third investigation examined 120 participants belonging to Russian families of Moscow. Both last two investigations obtained very similar results on the use of colours, and gave a confirmation of the relevance of the Colour Family Drawing Test.
文摘Acupuncture therapy had established in China and it distributed among Asian countries and developed in each country as traditional medicine. In this project we compared the procedures and effects of traditional acupuncture therapies in China, Korea and Japan by using 10 healthy young male volunteers with written informed consent. Total white cell counts, leukocyte subsets and noradrenalin contents were used as outcomes. Three well trained traditional acupuncture therapists were chosen and they treated the same subjects at random order with intervals of at least two months. Each acupuncturist made his diagnosis and points selection for potentiate vital conditions. Clearly different procedures and point selections were used among three traditional acupuncture therapies on the same subject and the obtained changes of outcome measures also differed. Although variations of data were quite large, these results clearly demonstrated that acupuncture therapies have developed among three countries in unique manner.
基金China Global Change Research Program, No.2010CB950901 National Natural Science Foundation of China, No.41271227 No.41001122
文摘Land use/cover change is an important parameter in the climate and ecological simulations. Although they had been widely used in the community, SAGE dataset and HYDE dataset, the two representative global historical land use datasets, were little assessed about their accuracies in regional scale. Here, we carried out some assessments for the traditional cultivated region of China (TCRC) over last 300 years, by comparing SAGE2010 and HYDE (v3.1) with Chinese Historical Cropland Dataset (CHCD). The comparisons were performed at three spatial scales: entire study area, provincial area and 60 km by 60 km grid cell. The results show that (1) the cropland area from SAGE2010 was much more than that from CHCD moreover, the growth at a rate of 0.51% from 1700 to 1950 and -0.34% after 1950 were also inconsistent with that from CHCD. (2) HYDE dataset (v3.1) was closer to CHCD dataset than SAGE dataset on entire study area. However, the large biases could be detected at provincial scale and 60 km by 60 km grid cell scale. The percent of grid cells having biases greater than 70% (〈-70% or 〉70%) and 90% (〈-90% or 〉90%) accounted for 56%-63% and 40%-45% of the total grid cells respectively while those having biases range from -10% to 10% and from -30% to 30% account for only 5%-6% and 17% of the total grid cells respectively. (3) Using local historical archives to reconstruct historical dataset with high accuracy would be a valu- able way to improve the accuracy of climate and ecological simulation.
基金Supported by the National Natural Science Foundation of China(No. 60872070)
文摘One-class support vector machines (one-class SVMs) are powerful tools that are widely used in many applications. This paper describes a semi-supervised one-class SVM that uses supervision in terms of relative comparisons. The analysis uses a hypersphere version of one-class SVMs with a penalty term appended to the objective function. The method simultaneously finds the minimum sphere in the feature space that encloses most of the target points and considers the relative comparisons. The result is a standard convex quadratic programming problem, which can be solved by adapting standard methods for SVM training, i.e., sequential minimal optimization. This one-class SVM can be applied to semi-supervised clustering and multi-classification problems. Tests show that this method achieves higher accuracy and better generalization performance than previous SVMs.