The Antarctic ice sheet is the largest block of ice on Earth, a tiny change of its ice sheet will have a significant impact on sea level change, so it plays an important role in global climate change. The Gravity Reco...The Antarctic ice sheet is the largest block of ice on Earth, a tiny change of its ice sheet will have a significant impact on sea level change, so it plays an important role in global climate change. The Gravity Recovery and Climate Experiment （GRACE） mission, launched in 2002, provides an alternative method to monitor the Antarctic ice mass variation. The latest Release Level 05 （ RL05 ） version of GRACE time-variable gravity （TVG） data, derived from GRACE observations with improved quality and time-span over 10 years, were released by three GRACE data centers （CSR, JPL and GFZ） in April 2012, which gives us a chance to re-estimate the ice mass change over Antarctic more accurately. In this paper, we examine ice mass changes in regional scale, including Antarctic Peninsula （AP, West Antarctica）, Amundsen Sea Embayment （ASE, West Antarctica）, Lambert-Amery System （LAS, East Antarctica） and 27 drainage basins based on three data sets. The AP mass change rates are -12.03±0.74 Gt/a （CSR, 2004-2012）, -13.92±2.33 Gt/a （JPL, 2004 -2012） , -12.28±0.76 Gt/a （GFZ, 2005-2012） , with an acceleration of -1.50±0.25 Gt/a^2, -1.54±0.26 Gt/a^2, -0. 46±0.28 Gt/a^2 respectively, the ASE mass change rates are -89.22±1.93 Gt/a, -86.28± 2.20 Gt/a, -83.67±1.76 Gt/a with an acceleration of -10. 03±0. 65 Gt/a^2, -8.74±0. 74 Gt/a^2 and -5.69 ±0.68 Gt/a^2, and the LAS mass ehange rates are -4.31±1.95 Gt/a, -7.29±2. 84 Gt/a, 1.20±1.35 Gt/a with an acceleration of -0. 18±0.62 Gt/a^2, 3.55±0.95 Gt/a^2 and 0.97±0.49 Gt/a^2. The mass change rates derived from the three RL05 data are very close to each other both in AP and ASE with the uncertainties much smaller than the change rates, and mass losses are significantly accelerated since 2007 in AP and 2006 in ASE, respectively. However, the mass change rates are significantly different in LAS, negative rate from CSR and JPL data, but positive rate from GFZ data, the uncertainties are even larger than the correspondent change rates. With regard to the 27 drainage basins, seven basins （basin 3-9） located in the east Antarctica show positive mass change rates, and the rest twenty basins are characterized by negative mass change rates during the time span of the three RL05 data.展开更多
Using mass and chemical changes, behavior of some elements have been evaluated in the study area, Yamaghan Occurrence. The techniques using immobile elements can precisely identify altered volcanic rock precursors and...Using mass and chemical changes, behavior of some elements have been evaluated in the study area, Yamaghan Occurrence. The techniques using immobile elements can precisely identify altered volcanic rock precursors and measure material changes. The rocks of the study area were affected by hydrothermal alteration. Testing of some compatible incompatible and compatible compatible immobile pairs indicates that Al 2O 3 is the most immobile component in the study area. It means that during the three main stages of hydrothermal alteration (phyllic, intermediate argillic and propylitic) aluminum was the most immobile and titanium was slightly immobile. Increases in mass mostly result from mineralization, silicification or carbonatization as voids and other open space fillings and may have replaced the part of glassy matrix. Mass addition has diluted the immobile elements at constant rates. Mass loss is commonly due to leaching of Si, Ca and Na 2O during chloritization and sericitization. The mass loss is recognized by increased proportions of inert minerals such as chlorite and sericite. Mineralographic studies in the study area shows the existence of a supergene zone. Calcocite and covellite are considered enriched minerals. Considering this evidence and mass change results, the enrichment of copper in the circulating fluid is suspected with occasional sulfide precipitation.展开更多
This study examined the mass change of the Antarctic ice sheet(AIS) based on ICESat and CryoSat-2 observations. We estimated the AIS exhibited mass losses of-101±15 Gt·aduring the ICESat period(Sept–Nov 200...This study examined the mass change of the Antarctic ice sheet(AIS) based on ICESat and CryoSat-2 observations. We estimated the AIS exhibited mass losses of-101±15 Gt·aduring the ICESat period(Sept–Nov 2003 to Sept–Oct 2009) and-186±55 Gt·aduring the CryoSat-2 period(Jan 2011 to Dec 2015). Mass losses occurred mainly in the sectors of the Amundsen and Bellingshausen seas. Benefitting from the 30-d subcycle of CryoSat-2, we obtained monthly estimates of mass evolution. Considerable annual variations were observed in the mass evolution sequences and the climatological monthly mass evolution. Seasonal mass evolutions in the sectors of the Bellingshausen and Amundsen seas were found most representative of the annual variation. The geographical distribution characteristics of interannual AIS mass evolution were revealed by the annual average mass evolution sequences. During Jan 2011 to Dec 2015, the ice sheets in the sectors of the Bellingshausen and Amundsen seas, and the Totten Glacier, experienced increasingly rapid areal mass loss. An area of mass gain with a moderate rate of increase was found between Dronning Maud Land and Enderby Land. Rapid mass accumulation has occurred in a limited area of the Kamb Ice Stream.展开更多
North China is a key region for studying geophysical progress. In this study, ground-based and Gravity Recovery and Climate Experiment（GRACE） gravity data from 2009 to 2013 are used to calculate the gravity change r...North China is a key region for studying geophysical progress. In this study, ground-based and Gravity Recovery and Climate Experiment（GRACE） gravity data from 2009 to 2013 are used to calculate the gravity change rate（GCR） using the polynomial fitting method. In general, the study area was divided into the Shanxi rift, Jing-Jin-Ji（Beijing-Tianjin-Hebei Province）, and Bohai Bay Basin（BBB） regions. Results of the distribution of the GCR determined from ground-based gravimetry show that the GCR appears to be ＂negativepositive-negative＂ from west to east, which indicates that different geophysical mechanisms are involved in the tectonic activities of these regions. However, GRACE solutions are conducted over a larger spatial scale and are able to show a difference between southern and northern areas and a mass redistribution of land water storage.展开更多
Multiproxy investigations have been performed on Core 08P23 collected from the Chukchi Plateau, the western Arctic Ocean, during the Third Chinese National Arctic Expedition. The core was dated back to Ma-rine Isotope...Multiproxy investigations have been performed on Core 08P23 collected from the Chukchi Plateau, the western Arctic Ocean, during the Third Chinese National Arctic Expedition. The core was dated back to Ma-rine Isotope Stage （MIS） 3 by a combination of Accelerator Mass Spectrometric （AMS） carbon-14 dating and regional core correlation. A total of five prominent ice-rafted detritus （IRD） events were recognized in MIS 2 and MIS 3. The IRD sources in MIS 3 are originated from vast carbonate rock outcrops of the Canadian Arctic Archipelago and clastic quartz in MIS 2 may have a Eurasian origin. Mostδ18O andδ13C values of Neogloboquadrina pachyderma （sinistral） （Nps） in Core 08P23 are lighter than the average values of surface sediments. The lighterδ18O andδ13C values of Nps in the two brown layers in MIS 1 and MIS 3 were resulted from meltwater events; and those in the gray layers in MIS 3 were caused by the enhanced sea ice formation. Theδ18O values varied inversely withδ13C in MIS 2 indicate that the study area was covered by thick sea ice or ice sheet with low temperature and little meltwater, which prevented the biological productivity and sea-atmosphere exchange, as well as water mass ventilation. The covaried light values ofδ18O andδ13C in MIS 1 and MIS 3 were resulted from meltwater and/or brine injection.展开更多
The Gravity Recovery and Climate Experiment(GRACE)is the most important gravity satellite to date in human history.Since its launch in 2002,GRACE time-varying gravity has had an unprecedented impact on earth science a...The Gravity Recovery and Climate Experiment(GRACE)is the most important gravity satellite to date in human history.Since its launch in 2002,GRACE time-varying gravity has had an unprecedented impact on earth science and has generated revolutionary changes.Because of natural phenomena such as climate warming,glacial melting,sea level rise,and earthquakes,earth science research has become an increasingly popular discipline in recent years.This article summarizes the importance of GRACE time-varying gravity,its application to geoscience,and its development.We analyzed the historical development and current status of GRACE time-varying gravity as well as research hotspots by searching the literature in the core collection databases of the China National Knowledge Infrastructure and the Web of Science over the past 20 years.The CiteSpace and VOSviewer software packages were applied with reference to the principle of literature metrology.Our investigation and analysis of characteristic indexes,such as the numbers of publications,co-occurrence of keywords,and co-citation of documents,uncovered the wide application and promotion of gravity satellites,especially GRACE time-varying gravity,in earth science.The results showed that the number of publications addressing GRACE data and time-varying gravity theory is increasing annually and that the USA,China,and Germany are the main producers.The Chinese Academy of Sciences,the National Aeronautics and Space Administration of the United States,and the Helmholtz Association of German Research Centres rank among the top three institutions in the world in terms of producing the most publications on this topic.We found that GRACE time-varying gravity plays unique roles in measuring changes in terrestrial water storage changes,ice and snow melting and sea level changes,and(co)seismic gravity changes,as well as in promoting other disciplines.展开更多
The prognostic role of body composition indexes,and specifically sarcopenia,has recently been explored in different cancer types.However,conflicting results have been reported.Heterogeneity in cancer type,cancer stage...The prognostic role of body composition indexes,and specifically sarcopenia,has recently been explored in different cancer types.However,conflicting results have been reported.Heterogeneity in cancer type,cancer stage or oncological treatments,as well as different methodology and definition of sarcopenia,could be accounted for different conclusions retrieved from literature.When focusing on colorectal cancer,it clearly appears that colon and rectal cancers are often treated as a single entity though they have different behaviors and treatments.Particularly,patients with advanced rectal cancer represent a peculiar group of patients that according to current guidelines are treated with neoadjuvant chemotherapy and radiotherapy followed by radical surgery.This review was restricted to a homogeneous group of patients with advanced lower rectal cancer and the aim of exploring whether there is a correlation between skeletal muscle depletion and prognosis.Literature was searched for articles related to patients with advanced rectal cancer undergoing neoadjuvant chemo-radiotherapy(NCRT)followed by radical surgery,in whom muscle mass and/or change in muscle mass during neoadjuvant treatment were measured.Eight full-text articles were selected and included in the present review.The main findings of our review were:(1)The majority of the studies defined sarcopenia as muscle mass alone over muscle strength or physical performance;(2)There was a great deal of heterogeneity in the definition and measures of sarcopenia,in the definition of cut-off values,and in the method to measure change in muscle mass;(3)There was not full agreement on the association between sarcopenia at baseline and/or after chemoradiotherapy and prognosis,and only few studies found a significance in the multivariate analysis;and(4)It seems that a loss in skeletal muscle mass during NCRT is associated with the worst outcomes in terms of disease-free survival.In conclusion,analysis of muscle mass might provide prognostic information on patients with rectal cancer,however more robust evidence is needed to define the role of muscle depletion and/or muscle change during neoadjuvant treatments,related to this specific group of patients.If a prognostic role would be confirmed by future studies,the role of preoperative intervention aimed at modifying muscle mass could be explored in order to improve outcomes.展开更多
In this paper we present a series of monthly gravity field solutions from Gravity Recovery and Climate Experiment（GRACE） range measurements using modified short arc approach,in which the ambiguity of range measureme...In this paper we present a series of monthly gravity field solutions from Gravity Recovery and Climate Experiment（GRACE） range measurements using modified short arc approach,in which the ambiguity of range measurements is eliminated via differentiating two adjacent range measurements.The data used for developing our monthly gravity field model are same as Tongji-GRACEOl model except that the range measurements are used to replace the range rate measurements,and our model is truncated to degree and order 60,spanning Jan.2004 to Dec.2010 also same as Tongji-GRACE01 model.Based on the comparison results of the C_（2,0）,C_（2,1）,S_（2,1）,and C_（15,15）,S_（15,15）,time series and the global mass change signals as well as the mass change time series in Amazon area of our model with those of Tongji-GRACE01 model,we can conclude that our monthly gravity field model is comparable with Tongji-GRACE01 monthly model.展开更多
Total sea level variations（SLVs） are caused by two major components：steric variations due to thermal expansion of seawater,and mass-induced variations due to mass exchange between ocean and land.In this study,the g...Total sea level variations（SLVs） are caused by two major components：steric variations due to thermal expansion of seawater,and mass-induced variations due to mass exchange between ocean and land.In this study,the global SLV and its steric and mass components were estimated by satellite altimetry,Argo float data and the Gravity Recovery and Climate Experiment（GRACE） data over 2005-2014.Space gravimetry observations from GRACE suggested that two-thirds of the global mean sea level rise rate observed by altimetry（i.e.,3.1 ± 0.3 mm/a from 2005 to 2014） could be explained by an increase in ocean mass.Furthermore,the global mean sea level was observed to drop significantly during the2010/2011 La Nina event,which may be attributed to the decline of ocean mass and steric SLV.Since early 2011,the global mean sea level began to rise rapidly,which was attributed to an increase in ocean mass.The findings in this study suggested that the global mean sea-level budget was closed from 2005 to 2014 based on altimetry,GRACE,and Argo data.展开更多
A physical phenomenon can be duplicated similarly to different phenomenon. Based on these facts, the application of physics phenomenon model towards the economic cases that occurred in Indonesia will be discussed. Phy...A physical phenomenon can be duplicated similarly to different phenomenon. Based on these facts, the application of physics phenomenon model towards the economic cases that occurred in Indonesia will be discussed. Physical phenomenon to be discussed is the loaded oscillation spring, while the economic case is the dynamics of the Rupiah against foreign currencies, namely U.S. Dollars. Symptoms of the analyzed oscillations involve vibration load on the spring, with the mass load changes against time; for free oscillation, damped oscillation, forced oscillation, as well as forced damped oscillation. Oscillation is modeled into a non homogenous second order differential equation, which results in a solution of the deviation function of time in the form of logarithmic harmonic function. Obtained solutions of physical phenomenon model are matched with the dynamics of the exchange rate data for both steady state, as well as to the condition shortly after the surge （crash）. Models are quite satisfactory, especially when being associated with the occurrence of momentary interruption followed by a relaxation mechanism, both for amplitude and period.展开更多
To accurately evaluate the Antarctic Ice Sheet(AIS)mass change rate and its spatiotemporal characteristics,we derive the AIS mass change series from April 2002 to December 2023 using an improved point-mass model appro...To accurately evaluate the Antarctic Ice Sheet(AIS)mass change rate and its spatiotemporal characteristics,we derive the AIS mass change series from April 2002 to December 2023 using an improved point-mass model approach with datadriven regularization matrices and iteratively determined multiple regularization parameters.Then,we analyze the spatiotemporal characteristics of the mass change rate over the AIS,focusing on four glacier basins in the Wilkes Land-Queen Mary Land(WL-QML)region of the East AIS(EAIS),namely the Denman,Moscow,Totten,and Vincennes Bay glacier basins.The results indicate that the AIS contribution to GMSL(global mean sea level)rise peaked at 5.99±0.43 mm in February 2020,followed by a mass gain period lasting over three years,ultimately resulting in a total GMSL contribution of 5.10±0.52 mm by the end of 2023.Moreover,the AIS experienced substantial mass loss during the 2011–2020 period,with a rate of 142.06±56.12Gt a-1,mainly due to intensified mass loss in the West AIS and the WL-QML region of the EAIS.Further analysis shows that the mass loss rate of the four glacier basins in the WL-QML region during the 2011–2020 period increased by 47.64±8.14 Gt a-1compared with the 2002–2010 period,with expanded areas of mass loss spreading inland.Notably,the Vincennes Bay and Denman glacier basins transitioned from mass balance and accumulation to intense mass loss,respectively.An in-depth investigation reveals that the increased ice discharge and decreased SMB(surface mass balance)contribute 27.47%and 72.53%,respectively,to the intensified mass loss of the four glacier basins.Overall,the study presents the mass change characteristics of the AIS over the past 22 years,highlights the instability of four important glacier basins in the EAIS,and provides valuable scientific insights for related polar research.展开更多
Floating MPs is a transboundary pollutant.Its transboundary nature and dynamics warrant deep know-how,not only on its transport and fate properties but also on understanding its mass change,which is a priority that ne...Floating MPs is a transboundary pollutant.Its transboundary nature and dynamics warrant deep know-how,not only on its transport and fate properties but also on understanding its mass change,which is a priority that needs relative addition for scientific dataset.This study highlights gravimetric analysis,another relevant technique to assess the accretion rate of pollutants,chemical risk and pollution load index on microplastics in the coastal waters of Limbe-Idenau,Cameroon.Sea-water samples were fished in five offshore distances in three distinct depth points in five purposive beaches on line transects.9 samples/beach with 45/season amounting to 90 bottled water samples and each collected sample were stored in 1 L glass bottle for further analysis.Systematic sample filtration,content weighing and reweighing after oven drying,and plastic mass calculation were done,aided by 4X magnification for plastic characterisation.178 MPs particles were identified with five unique particle weighs of 0.0000 g(150/0.0015 g),0.001 g(20/0.02 g),0.002 g(1/0.002 g),0.003 g(5/0.015 g)and 0.011 g(2/0.022 g)weighing 0.605 g.The most frequently observed plastic was the 0.0000 g weighed particle with physical appearance of RWPP>IWPP>OWPP in all the sampled seawater.In terms of weighs MPs analysis,the dominant beach,offshore distance,size ranged,abundance/season and physical outlook parameters in particle/number were recorded as follows:LBD 1(29.2%),5 m offshore distance(59.6%),1-1.5 m size ranged(55%)with mean size detection limits of 0.2 cm and dry season(77.5%).Lastly,the plastic physical outlook revealed that old weathered plastic particle,OWPP(51.1%)was dominant with large plastic mass loss experienced more during the rainy season.0.011 g weight plastic showed the highest average mass loss/particle(17.2%).Evidence from this study has reaffirmed that mass gained by certain weightless plastic indicates their long-time existence,knowledge of distance from sourced and fragmenting capacity within the marine environment.Both CF(2.71)and PLI(1.47)show a level II risk factor meanwhile the RQ value indicates a low rate potential of risk of degrees of injuries or damages to both marine organisms and beach users which requires urgent environmental management and pollution control strategies.展开更多
基金mainly sponsored by National key Basic Research Program of China(973 Program:2012CB957703)Natural Science Foundation of China(41274035)
文摘The Antarctic ice sheet is the largest block of ice on Earth, a tiny change of its ice sheet will have a significant impact on sea level change, so it plays an important role in global climate change. The Gravity Recovery and Climate Experiment （GRACE） mission, launched in 2002, provides an alternative method to monitor the Antarctic ice mass variation. The latest Release Level 05 （ RL05 ） version of GRACE time-variable gravity （TVG） data, derived from GRACE observations with improved quality and time-span over 10 years, were released by three GRACE data centers （CSR, JPL and GFZ） in April 2012, which gives us a chance to re-estimate the ice mass change over Antarctic more accurately. In this paper, we examine ice mass changes in regional scale, including Antarctic Peninsula （AP, West Antarctica）, Amundsen Sea Embayment （ASE, West Antarctica）, Lambert-Amery System （LAS, East Antarctica） and 27 drainage basins based on three data sets. The AP mass change rates are -12.03±0.74 Gt/a （CSR, 2004-2012）, -13.92±2.33 Gt/a （JPL, 2004 -2012） , -12.28±0.76 Gt/a （GFZ, 2005-2012） , with an acceleration of -1.50±0.25 Gt/a^2, -1.54±0.26 Gt/a^2, -0. 46±0.28 Gt/a^2 respectively, the ASE mass change rates are -89.22±1.93 Gt/a, -86.28± 2.20 Gt/a, -83.67±1.76 Gt/a with an acceleration of -10. 03±0. 65 Gt/a^2, -8.74±0. 74 Gt/a^2 and -5.69 ±0.68 Gt/a^2, and the LAS mass ehange rates are -4.31±1.95 Gt/a, -7.29±2. 84 Gt/a, 1.20±1.35 Gt/a with an acceleration of -0. 18±0.62 Gt/a^2, 3.55±0.95 Gt/a^2 and 0.97±0.49 Gt/a^2. The mass change rates derived from the three RL05 data are very close to each other both in AP and ASE with the uncertainties much smaller than the change rates, and mass losses are significantly accelerated since 2007 in AP and 2006 in ASE, respectively. However, the mass change rates are significantly different in LAS, negative rate from CSR and JPL data, but positive rate from GFZ data, the uncertainties are even larger than the correspondent change rates. With regard to the 27 drainage basins, seven basins （basin 3-9） located in the east Antarctica show positive mass change rates, and the rest twenty basins are characterized by negative mass change rates during the time span of the three RL05 data.
文摘Using mass and chemical changes, behavior of some elements have been evaluated in the study area, Yamaghan Occurrence. The techniques using immobile elements can precisely identify altered volcanic rock precursors and measure material changes. The rocks of the study area were affected by hydrothermal alteration. Testing of some compatible incompatible and compatible compatible immobile pairs indicates that Al 2O 3 is the most immobile component in the study area. It means that during the three main stages of hydrothermal alteration (phyllic, intermediate argillic and propylitic) aluminum was the most immobile and titanium was slightly immobile. Increases in mass mostly result from mineralization, silicification or carbonatization as voids and other open space fillings and may have replaced the part of glassy matrix. Mass addition has diluted the immobile elements at constant rates. Mass loss is commonly due to leaching of Si, Ca and Na 2O during chloritization and sericitization. The mass loss is recognized by increased proportions of inert minerals such as chlorite and sericite. Mineralographic studies in the study area shows the existence of a supergene zone. Calcocite and covellite are considered enriched minerals. Considering this evidence and mass change results, the enrichment of copper in the circulating fluid is suspected with occasional sulfide precipitation.
基金funded by the Key Program of National Natural Science Foundation of China (Grant no. 41531069)the Chinese Polar Environment Comprehensive Investigation and Assessment Programs (Grant no. CHINARE2016-02-02)
文摘This study examined the mass change of the Antarctic ice sheet(AIS) based on ICESat and CryoSat-2 observations. We estimated the AIS exhibited mass losses of-101±15 Gt·aduring the ICESat period(Sept–Nov 2003 to Sept–Oct 2009) and-186±55 Gt·aduring the CryoSat-2 period(Jan 2011 to Dec 2015). Mass losses occurred mainly in the sectors of the Amundsen and Bellingshausen seas. Benefitting from the 30-d subcycle of CryoSat-2, we obtained monthly estimates of mass evolution. Considerable annual variations were observed in the mass evolution sequences and the climatological monthly mass evolution. Seasonal mass evolutions in the sectors of the Bellingshausen and Amundsen seas were found most representative of the annual variation. The geographical distribution characteristics of interannual AIS mass evolution were revealed by the annual average mass evolution sequences. During Jan 2011 to Dec 2015, the ice sheets in the sectors of the Bellingshausen and Amundsen seas, and the Totten Glacier, experienced increasingly rapid areal mass loss. An area of mass gain with a moderate rate of increase was found between Dronning Maud Land and Enderby Land. Rapid mass accumulation has occurred in a limited area of the Kamb Ice Stream.
基金supported by the National Natural Science Foundation of China(41304060)the national key basic research and development plan(2013CB733304)
文摘North China is a key region for studying geophysical progress. In this study, ground-based and Gravity Recovery and Climate Experiment（GRACE） gravity data from 2009 to 2013 are used to calculate the gravity change rate（GCR） using the polynomial fitting method. In general, the study area was divided into the Shanxi rift, Jing-Jin-Ji（Beijing-Tianjin-Hebei Province）, and Bohai Bay Basin（BBB） regions. Results of the distribution of the GCR determined from ground-based gravimetry show that the GCR appears to be ＂negativepositive-negative＂ from west to east, which indicates that different geophysical mechanisms are involved in the tectonic activities of these regions. However, GRACE solutions are conducted over a larger spatial scale and are able to show a difference between southern and northern areas and a mass redistribution of land water storage.
基金The National Natural Science Foundation of China under contract Nos 41030859,41211120173,CHINARE2015-03-02 and IC201105the Geological Investigation Project of China Geological Survey Nos 12120113006200 and 1212011120044
文摘Multiproxy investigations have been performed on Core 08P23 collected from the Chukchi Plateau, the western Arctic Ocean, during the Third Chinese National Arctic Expedition. The core was dated back to Ma-rine Isotope Stage （MIS） 3 by a combination of Accelerator Mass Spectrometric （AMS） carbon-14 dating and regional core correlation. A total of five prominent ice-rafted detritus （IRD） events were recognized in MIS 2 and MIS 3. The IRD sources in MIS 3 are originated from vast carbonate rock outcrops of the Canadian Arctic Archipelago and clastic quartz in MIS 2 may have a Eurasian origin. Mostδ18O andδ13C values of Neogloboquadrina pachyderma （sinistral） （Nps） in Core 08P23 are lighter than the average values of surface sediments. The lighterδ18O andδ13C values of Nps in the two brown layers in MIS 1 and MIS 3 were resulted from meltwater events; and those in the gray layers in MIS 3 were caused by the enhanced sea ice formation. Theδ18O values varied inversely withδ13C in MIS 2 indicate that the study area was covered by thick sea ice or ice sheet with low temperature and little meltwater, which prevented the biological productivity and sea-atmosphere exchange, as well as water mass ventilation. The covaried light values ofδ18O andδ13C in MIS 1 and MIS 3 were resulted from meltwater and/or brine injection.
基金supported by the National Natural Science Foundation of China(Grant Nos.42174097,41974093,and 41774088).
文摘The Gravity Recovery and Climate Experiment(GRACE)is the most important gravity satellite to date in human history.Since its launch in 2002,GRACE time-varying gravity has had an unprecedented impact on earth science and has generated revolutionary changes.Because of natural phenomena such as climate warming,glacial melting,sea level rise,and earthquakes,earth science research has become an increasingly popular discipline in recent years.This article summarizes the importance of GRACE time-varying gravity,its application to geoscience,and its development.We analyzed the historical development and current status of GRACE time-varying gravity as well as research hotspots by searching the literature in the core collection databases of the China National Knowledge Infrastructure and the Web of Science over the past 20 years.The CiteSpace and VOSviewer software packages were applied with reference to the principle of literature metrology.Our investigation and analysis of characteristic indexes,such as the numbers of publications,co-occurrence of keywords,and co-citation of documents,uncovered the wide application and promotion of gravity satellites,especially GRACE time-varying gravity,in earth science.The results showed that the number of publications addressing GRACE data and time-varying gravity theory is increasing annually and that the USA,China,and Germany are the main producers.The Chinese Academy of Sciences,the National Aeronautics and Space Administration of the United States,and the Helmholtz Association of German Research Centres rank among the top three institutions in the world in terms of producing the most publications on this topic.We found that GRACE time-varying gravity plays unique roles in measuring changes in terrestrial water storage changes,ice and snow melting and sea level changes,and(co)seismic gravity changes,as well as in promoting other disciplines.
文摘The prognostic role of body composition indexes,and specifically sarcopenia,has recently been explored in different cancer types.However,conflicting results have been reported.Heterogeneity in cancer type,cancer stage or oncological treatments,as well as different methodology and definition of sarcopenia,could be accounted for different conclusions retrieved from literature.When focusing on colorectal cancer,it clearly appears that colon and rectal cancers are often treated as a single entity though they have different behaviors and treatments.Particularly,patients with advanced rectal cancer represent a peculiar group of patients that according to current guidelines are treated with neoadjuvant chemotherapy and radiotherapy followed by radical surgery.This review was restricted to a homogeneous group of patients with advanced lower rectal cancer and the aim of exploring whether there is a correlation between skeletal muscle depletion and prognosis.Literature was searched for articles related to patients with advanced rectal cancer undergoing neoadjuvant chemo-radiotherapy(NCRT)followed by radical surgery,in whom muscle mass and/or change in muscle mass during neoadjuvant treatment were measured.Eight full-text articles were selected and included in the present review.The main findings of our review were:(1)The majority of the studies defined sarcopenia as muscle mass alone over muscle strength or physical performance;(2)There was a great deal of heterogeneity in the definition and measures of sarcopenia,in the definition of cut-off values,and in the method to measure change in muscle mass;(3)There was not full agreement on the association between sarcopenia at baseline and/or after chemoradiotherapy and prognosis,and only few studies found a significance in the multivariate analysis;and(4)It seems that a loss in skeletal muscle mass during NCRT is associated with the worst outcomes in terms of disease-free survival.In conclusion,analysis of muscle mass might provide prognostic information on patients with rectal cancer,however more robust evidence is needed to define the role of muscle depletion and/or muscle change during neoadjuvant treatments,related to this specific group of patients.If a prognostic role would be confirmed by future studies,the role of preoperative intervention aimed at modifying muscle mass could be explored in order to improve outcomes.
基金sponsored by National Natural Science Foundation of China(41474017)National Key Basic Research Program of China(973 Program+3 种基金2012CB957703)sponsored by National Natural Science Foundation of China(41274035)State Key Laboratory of Geodesy and Earth's Dynamics(SKLGED2013-3-2-Z,SKLGED2014-1-3-E)State Key Laboratory of Geo-Information Engineering(SKLGIE2014-M-1-2)
文摘In this paper we present a series of monthly gravity field solutions from Gravity Recovery and Climate Experiment（GRACE） range measurements using modified short arc approach,in which the ambiguity of range measurements is eliminated via differentiating two adjacent range measurements.The data used for developing our monthly gravity field model are same as Tongji-GRACEOl model except that the range measurements are used to replace the range rate measurements,and our model is truncated to degree and order 60,spanning Jan.2004 to Dec.2010 also same as Tongji-GRACE01 model.Based on the comparison results of the C_（2,0）,C_（2,1）,S_（2,1）,and C_（15,15）,S_（15,15）,time series and the global mass change signals as well as the mass change time series in Amazon area of our model with those of Tongji-GRACE01 model,we can conclude that our monthly gravity field model is comparable with Tongji-GRACE01 monthly model.
基金supported by the National Key Basic Research Program of China(973 program,2012CB957703 and2013CB733305)the National Natural Science Foundation of China(41431070,41174066 and 41321063)
文摘Total sea level variations（SLVs） are caused by two major components：steric variations due to thermal expansion of seawater,and mass-induced variations due to mass exchange between ocean and land.In this study,the global SLV and its steric and mass components were estimated by satellite altimetry,Argo float data and the Gravity Recovery and Climate Experiment（GRACE） data over 2005-2014.Space gravimetry observations from GRACE suggested that two-thirds of the global mean sea level rise rate observed by altimetry（i.e.,3.1 ± 0.3 mm/a from 2005 to 2014） could be explained by an increase in ocean mass.Furthermore,the global mean sea level was observed to drop significantly during the2010/2011 La Nina event,which may be attributed to the decline of ocean mass and steric SLV.Since early 2011,the global mean sea level began to rise rapidly,which was attributed to an increase in ocean mass.The findings in this study suggested that the global mean sea-level budget was closed from 2005 to 2014 based on altimetry,GRACE,and Argo data.
文摘A physical phenomenon can be duplicated similarly to different phenomenon. Based on these facts, the application of physics phenomenon model towards the economic cases that occurred in Indonesia will be discussed. Physical phenomenon to be discussed is the loaded oscillation spring, while the economic case is the dynamics of the Rupiah against foreign currencies, namely U.S. Dollars. Symptoms of the analyzed oscillations involve vibration load on the spring, with the mass load changes against time; for free oscillation, damped oscillation, forced oscillation, as well as forced damped oscillation. Oscillation is modeled into a non homogenous second order differential equation, which results in a solution of the deviation function of time in the form of logarithmic harmonic function. Obtained solutions of physical phenomenon model are matched with the dynamics of the exchange rate data for both steady state, as well as to the condition shortly after the surge （crash）. Models are quite satisfactory, especially when being associated with the occurrence of momentary interruption followed by a relaxation mechanism, both for amplitude and period.
基金supported by the National Natural Science Foundation of China(Grant Nos.42394131&42274005)。
文摘To accurately evaluate the Antarctic Ice Sheet(AIS)mass change rate and its spatiotemporal characteristics,we derive the AIS mass change series from April 2002 to December 2023 using an improved point-mass model approach with datadriven regularization matrices and iteratively determined multiple regularization parameters.Then,we analyze the spatiotemporal characteristics of the mass change rate over the AIS,focusing on four glacier basins in the Wilkes Land-Queen Mary Land(WL-QML)region of the East AIS(EAIS),namely the Denman,Moscow,Totten,and Vincennes Bay glacier basins.The results indicate that the AIS contribution to GMSL(global mean sea level)rise peaked at 5.99±0.43 mm in February 2020,followed by a mass gain period lasting over three years,ultimately resulting in a total GMSL contribution of 5.10±0.52 mm by the end of 2023.Moreover,the AIS experienced substantial mass loss during the 2011–2020 period,with a rate of 142.06±56.12Gt a-1,mainly due to intensified mass loss in the West AIS and the WL-QML region of the EAIS.Further analysis shows that the mass loss rate of the four glacier basins in the WL-QML region during the 2011–2020 period increased by 47.64±8.14 Gt a-1compared with the 2002–2010 period,with expanded areas of mass loss spreading inland.Notably,the Vincennes Bay and Denman glacier basins transitioned from mass balance and accumulation to intense mass loss,respectively.An in-depth investigation reveals that the increased ice discharge and decreased SMB(surface mass balance)contribute 27.47%and 72.53%,respectively,to the intensified mass loss of the four glacier basins.Overall,the study presents the mass change characteristics of the AIS over the past 22 years,highlights the instability of four important glacier basins in the EAIS,and provides valuable scientific insights for related polar research.
文摘Floating MPs is a transboundary pollutant.Its transboundary nature and dynamics warrant deep know-how,not only on its transport and fate properties but also on understanding its mass change,which is a priority that needs relative addition for scientific dataset.This study highlights gravimetric analysis,another relevant technique to assess the accretion rate of pollutants,chemical risk and pollution load index on microplastics in the coastal waters of Limbe-Idenau,Cameroon.Sea-water samples were fished in five offshore distances in three distinct depth points in five purposive beaches on line transects.9 samples/beach with 45/season amounting to 90 bottled water samples and each collected sample were stored in 1 L glass bottle for further analysis.Systematic sample filtration,content weighing and reweighing after oven drying,and plastic mass calculation were done,aided by 4X magnification for plastic characterisation.178 MPs particles were identified with five unique particle weighs of 0.0000 g(150/0.0015 g),0.001 g(20/0.02 g),0.002 g(1/0.002 g),0.003 g(5/0.015 g)and 0.011 g(2/0.022 g)weighing 0.605 g.The most frequently observed plastic was the 0.0000 g weighed particle with physical appearance of RWPP>IWPP>OWPP in all the sampled seawater.In terms of weighs MPs analysis,the dominant beach,offshore distance,size ranged,abundance/season and physical outlook parameters in particle/number were recorded as follows:LBD 1(29.2%),5 m offshore distance(59.6%),1-1.5 m size ranged(55%)with mean size detection limits of 0.2 cm and dry season(77.5%).Lastly,the plastic physical outlook revealed that old weathered plastic particle,OWPP(51.1%)was dominant with large plastic mass loss experienced more during the rainy season.0.011 g weight plastic showed the highest average mass loss/particle(17.2%).Evidence from this study has reaffirmed that mass gained by certain weightless plastic indicates their long-time existence,knowledge of distance from sourced and fragmenting capacity within the marine environment.Both CF(2.71)and PLI(1.47)show a level II risk factor meanwhile the RQ value indicates a low rate potential of risk of degrees of injuries or damages to both marine organisms and beach users which requires urgent environmental management and pollution control strategies.
