Objective:To evaluate the sensitivity pattern of bacterial pathogens in the intensive care unit(ICU) of a tertiary care of Falmawati Hospital Jakarta Indonesia.Methods:A cross sectional retrospective study of bacteria...Objective:To evaluate the sensitivity pattern of bacterial pathogens in the intensive care unit(ICU) of a tertiary care of Falmawati Hospital Jakarta Indonesia.Methods:A cross sectional retrospective study of bacterial pathogen was carried out on a total of 722 patients that were admitted to the ICU of Fatmawati Hospital Jakarta Indonesia during January 2009 to March 2010. All bacteria were identified by standard microbiologic methods,and(heir antibiotic susceptibility testing was performed using disk diffusion method.Results:Specimens were collected from 385 patients who were given antimicrobial treatment,of which 249(64.68%) were cultured positive and 136(35.32%) were negative.The most predominant isolate was Pseudomonas aeruginosa(P.aeruginosa)(26.5%) followed by Klebsiella pneumoniae(K.pneumoniae)(15.3%) and Staphylococcus epidermidis(14.9%).P.aeruginosa isolates showed high rate of resistance to cephalexin(95.3%),cefotaxime(64.1%),and ceftriaxone(60.9%).Amikacin was the most effective(84.4%) antibiotic against P.aeruginosa followed by imipenem(81.2%),and meropenem(75.0%).K.pneumoniae showed resistance to cephalexin(86.5%),ceftriaxone(75.7%),ceftazidime(73.0%),cefpirome(73.0%) and cefotaxime(67.9%),respectively.Conclusions:Most bacteria isolated from ICU of Fatmawati Hospital Jakarta Indonesia were resistant to the third generation of cephalosporins,and quinolone antibiotics.Regular surveillance of antibiotic susceptibility pallerns is very important for setting orders to guide the clinician in choosing empirical or directed therapy of infected patients.展开更多
Background: The prognostic values of staging parameters require continual re?assessment amid changes in diag?nostic and therapeutic methods. This study aimed to identify the prognostic factors and failure patterns of ...Background: The prognostic values of staging parameters require continual re?assessment amid changes in diag?nostic and therapeutic methods. This study aimed to identify the prognostic factors and failure patterns of non?meta?static nasopharyngeal carcinoma(NPC) in the intensity?modulated radiotherapy(IMRT) era.Methods: We reviewed the data from 749 patients with newly diagnosed, biopsy?proven, non?metastatic NPC in our cancer center(South China, an NPC endemic area) between January 2003 and December 2007. All patients under?went magnetic resonance imaging(MRI) before receiving IMRT. The actuarial survival rates were estimated using the Kaplan–Meier method, and survival curves were compared using the log?rank test. Multivariate analyses with the Cox proportional hazards model were used to test for the independent prognostic factors by backward eliminating insigniicant explanatory variables.Results: The 5?year occurrence rates of local failure, regional failure, locoregional failure, and distant failure were 5.4, 3.0, 7.4, and 17.4%, respectively. The 5?year survival rates were as follows: local relapse?free survival, 94.6%; nodal relapse?free survival, 97.0%; distant metastasis?free survival, 82.6%; disease?free survival, 75.1%; and overall survival, 82.0%. Multivariate Cox regression analysis revealed that orbit involvement was the only signiicant prognostic fac?tor for local failure(P = 0.011). Parapharyngeal tumor extension, retropharyngeal lymph node involvement, and the laterality, longest diameter, and Ho's location of the cervical lymph nodes were signiicant prognostic factors for both distant failure and disease failure(all P < 0.05). Intracranial extension had signiicant prognostic value for distant failure(P = 0.040).Conclusions: The key failure pattern for NPC was distant metastasis in the IMRT era. With changes in diagnostic and therapeutic technologies as well as treatment modalities, the signiicant prognostic parameters for local control have also been altered substantially.展开更多
BACKGROUND Ventilator-associated pneumonia(VAP)is defined as pneumonia that occurs two calendar days following endotracheal intubation or after that.It is the most common infection encountered among intubated patients...BACKGROUND Ventilator-associated pneumonia(VAP)is defined as pneumonia that occurs two calendar days following endotracheal intubation or after that.It is the most common infection encountered among intubated patients.VAP incidence showed wide variability between countries.AIM To define the VAP incidence in the intensive care unit(ICU)in the central gove-rnment hospital in Bahrain and review the risk factors and the predominant bacterial pathogens with their antimicrobial susceptibility pattern.METHODS The research was a prospective cross-sectional observational study over six months from November 2019 to June 2020.It included adult and adolescent patients(>14 years old)admitted to the ICU and required intubation and mechanical ventilation.VAP was diagnosed when it occurred after 48 h after endotracheal intubation using the clinical pulmonary infection score,which considers the clinical,laboratory,microbiological,and radiographic evidence.RESULTS The total number of adult patients admitted to the ICU who required intubation and mechanical ventilation during the study period was 155.Forty-six patients developed VAP during their ICU stay(29.7%).The calculated VAP rate was 22.14 events per 1000 ventilator days during the study period,with a mean age of 52 years±20.Most VAP cases had late-onset VAP with a mean number of ICU days before the development of VAP of 9.96±6.55.Gram-negative contributed to most VAP cases in our unit,with multidrug-resistant Acinetobacter being the most identified pathogen.CONCLUSION The reported VAP rate in our ICU was relatively high compared to the international benchmark,which should trigger a vital action plan for reinforcing the implementation of the VAP prevention bundle.展开更多
Speckle patterns are a fundamental tool in a variety of physical and optical applications. Here, we investigate a method of precisely tuning the intensity statistics of random speckle patterns into a desirable pattern...Speckle patterns are a fundamental tool in a variety of physical and optical applications. Here, we investigate a method of precisely tuning the intensity statistics of random speckle patterns into a desirable pattern that possesses the same spatial correlation length and similar statistics distribution. This tuning mechanism relies on the derivation of the transform function and transmission matrix, which achieves different contrasts while maintaining the same average value or energy level. The statistics properties of the generated speckle patterns are further investigated by analyzing the standard deviation under different fitting parameters. Precisely tuning the intensity statistics of random speckle patterns could be useful for both fundamental research and practical applications, such as microscopy, imaging, and optical manipulation.展开更多
<strong>Background: </strong><span style="font-family:;" "=""><span style="font-family:Verdana;">An intensive care unit (ICU) is a special unit of a hospital ...<strong>Background: </strong><span style="font-family:;" "=""><span style="font-family:Verdana;">An intensive care unit (ICU) is a special unit of a hospital that provides intensive treatment for patients with severe or life-threatening illnesses and injuries, which require constant care and close monitoring with life support equipment. The mortality rate is still very high in most ICUs especially in the developing countries due to late presentation of patients, unavailability of well trained staff and lack of life support equipment. There has not been any previous study on the mortality pattern in ICU of Alex Ekwueme Federal University Teaching Hospital Abakaliki (AEFUTHA). It is against this background that we embarked on this retrospective descriptive hospital based study of the mortality pattern in ICU of a Tertiary Hospital in Abakaliki, South-eastern Nigeria. </span><b><span style="font-family:Verdana;">Method: </span></b><span style="font-family:Verdana;">This is a retrospective descriptive hospital based study. The admission and discharge registers of the ICU ward were used to extract information on biodata, diagnosis, duration and outcome of all admissions from January to December 2019 (12</span></span><span style="font-family:Verdana;"> </span><span style="font-family:;" "=""><span style="font-family:Verdana;">months). </span><b><span style="font-family:Verdana;">Results: </span></b><span style="font-family:Verdana;">A total of 174 (male 113, female 71) patients were admitted over the 12</span></span><span style="font-family:Verdana;"> </span><span style="font-family:Verdana;">months period with mean age of 46.31</span><span style="font-family:Verdana;"> </span><span style="font-family:Verdana;">±</span><span style="font-family:Verdana;"> </span><span style="font-family:Verdana;">12.28</span><span style="font-family:Verdana;"> </span><span style="font-family:Verdana;">years. Seventy</span><span style="font-family:Verdana;">-</span><span style="font-family:;" "=""><span style="font-family:Verdana;">one (40.8%) of the patients died from predominantly stroke, acute abdomen, trauma, sepsis, renal failure, acute diabetic complications and cancer in descending order. Acute diabetic complications had 100% case fatality rate, followed by stroke (71%), renal failure (62.5%), cancer (60%), sepsis (55.5%), acute abdomen (34%) and trauma (23%). The mean duration of ICU admission was 4.2 days for the non-survivors and 6.3 days for survivors. </span><b><span style="font-family:Verdana;">Conclusion: </span></b><span style="font-family:Verdana;">The ICU mortality rate was high and constituted of mainly stroke, acute abdomen and trauma which are essentially preventable. Female sex, medical diagnosis and ICU admission duration of less than 6 days were associated with higher ICU mortality.</span></span>展开更多
Experimental validation of laser intensity is particularly important for the study of fundamental physics at extremely high intensities.However,reliable diagnosis of the focal spot and peak intensity faces huge challe...Experimental validation of laser intensity is particularly important for the study of fundamental physics at extremely high intensities.However,reliable diagnosis of the focal spot and peak intensity faces huge challenges.In this work,we demonstrate for the firs time that the coherent radiation farfiel patterns from laser–foil interactions can serve as an in situ,real-time,and easy-to-implement diagnostic for an ultraintense laser focus.The laser-driven electron sheets,curved by the spatially varying laser fiel and leaving the targets at nearly the speed of light,produce doughnut-shaped patterns depending on the shapes of the focal spot and the absolute laser intensities.Assisted by particle-in-cell simulations,we can achieve measurements of the intensity and the focal spot,and provide immediate feedback to optimize the focal spots for extremely high intensity.展开更多
Land use intensity quantifies the impacts of human activities on natural ecosystems, which have become the major driver of global environmental change, and thus it serves as an essential measurement for assessing land...Land use intensity quantifies the impacts of human activities on natural ecosystems, which have become the major driver of global environmental change, and thus it serves as an essential measurement for assessing land use sustainability. To date, land-change studies have mainly focused on changes in land cover and their effects on ecological processes, whereas land use intensity has not yet received the attention it deserves and for which spa- tially-explicit representation studies have only just begun. In this paper, according to the de- gree and reversibility of surface disturbance by human activities, there are four main classes of land use intensity： artificial land, semi-artificial land, semi-natural land, and natural land. These were further divided into 22 subclasses based on key indicators, such as human pop- ulation density and the cropping intensity. Land use intensity map of China at a 1-km spatial resolution was obtained based on satellite images and statistical data. The area proportions of artificial land, semi-artificial land, semi-natural land, and natural land were 0.71%, 19.36%, 58.93%, and 21%, respectively. Human and economic carrying capacity increased with the increase of land use intensity. Artificial land supports 24.58% and 35.62% of the total population and GDP, using only 0.71% of the total land, while semi-artificial land supported 58.24% and 49.61% of human population and GDP with 19.36% of China＇s total land area.展开更多
Based on remote sensing and GIS techniques, land use maps in 2000, 2005 and 2010 in China′s coastal zone were produced, and structural raster data of land use were further generated to calculate land use intensity co...Based on remote sensing and GIS techniques, land use maps in 2000, 2005 and 2010 in China′s coastal zone were produced, and structural raster data of land use were further generated to calculate land use intensity comprehensive index(LUICI) for analyzing land use spatial-temporal characteristics at 1 km scale. Results show that: 1) from the perspective of spatial patterns of landforms at a macro scale, there is a significant difference in land use intensity between the north and the south of China′s coastal zone. Hotspots of changes mainly concentrated in metropolitan areas, estuaries and coastal wetlands; 2) elevation is an important factor that controlling land use spatial patterns at local scale. Land use intensity is much higher within areas below the elevation of 400 m and it decreased significantly as the elevation increasing; 3) there is a significant land-ocean gradient for land use intensity, which is low in island and near-shore areas, but high in the regions that 4–30 km far away the coastline because of much intensive human activities; however, in recent decades land use intensity had been promoted significantly in low near-shore area due to extensive sea reclamations; 4) significant differences of land use intensity were also found among provincial administrative units. A rising trend of land use intensity was found in provincial-level administrative units from 2000 to 2010. To sum up, elevation, land-ocean gradient, socio-economic status and policy are all influencing factors to the spatial patterns and temporal variations of land use intensity in China′s coastal zone.展开更多
The spatial-temporal patterns of tropical cyclone(TC) intensity changes caused by the warm ocean mesoscale eddy(WOME) distribution are evaluated using two sets of idealized numerical experiments. The results show that...The spatial-temporal patterns of tropical cyclone(TC) intensity changes caused by the warm ocean mesoscale eddy(WOME) distribution are evaluated using two sets of idealized numerical experiments. The results show that the TC was intensified and weakened when a WOME was close to and far away from the TC center, respectively.The area where the WOME enhanced(weakened) TC intensity is called the inner(outer) area in this study.Amplitudes of the enhancement and weakening caused by the WOME in the inner and outer area decreased and increased over time, while the ranges of the inner and outer area diminished and expanded, respectively. The WOME in the inner area strengthened the secondary circulation of the TC, increased heat fluxes, strengthened the symmetry, and weakened the outer spiral rainband, which enhanced TC intensity. The effect was opposite if the WOME was in the outer area, and it weakened the TC intensity. The idealized simulation employed a stationary TC, and thus the results may only be applied to TCs with slow propagation. These findings can improve our understanding of the interactions between TC and the WOME and are helpful for improving TC intensity forecasting by considering the effect of the WOME in the outer areas.展开更多
The 21st century is referred to as a"century for cities"or"era for cities"and China hasalso speeded up its process of urbanization.It is veryimportant to choose a scientific urbanization patternto ...The 21st century is referred to as a"century for cities"or"era for cities"and China hasalso speeded up its process of urbanization.It is veryimportant to choose a scientific urbanization patternto exert the function of cities and realize our dreamfor China to become a powerful modernized country.It’s concluded from history since 1800 that the patternof the world urbanization has transformed from"extensive"to"intensive".However,it is still anextensive pattern in China,and there are manyproblems behind the splendid achievements,reflectedon the urbanization process of our country since1949.Today,sustainable development and theknowledge economy are the themes of the cities;itis inevitable to change our urbanization pattern.Based on the dialectic relationship of quality andquantity,the article points out that urbanizationshould not only focus on quantity but also on qualityin China.High quality and multiform urbanizationpattern is an inevitable choice of China,and thedevelopment of the region can also be exalted by theradiation of the cities.But what’s the real meaningof the new pattern?What’s its difference from thewestern countries’?The article discusses its contentaccording to the reality of China.展开更多
Although pruning is important to obtain highquality,large-diameter timber,the effects of pruning on nonstructural carbohydrates(NSC)in aboveground organs of many timber species are not well understood.Three intensitie...Although pruning is important to obtain highquality,large-diameter timber,the effects of pruning on nonstructural carbohydrates(NSC)in aboveground organs of many timber species are not well understood.Three intensities of pruning(none,moderate and severe)were tested on poplars(Populus alba×P.talassica)in the arid desert region of northwest China to compare the concentrations of soluble sugar(SS),starch(ST)and total nonstructural carbohydrate(TNC)in leaves,branches and trunks during the growing season.The concentration of NSC components after different pruning intensities varied similarly in seasonal patterns,increasing slowly at the beginning of the growing season,continuously declining in the middle,then gradually recovering by the end of the growing season.The monthly mean NSC concentration in poplar differed significantly among the three pruning intensities(p<0.05).The SS concentration in pruned trees was higher than in unpruned trees(p<0.05).For moderately pruned trees,the concentrations of ST and TNC in trunks and branches were higher than in unpruned and in severely pruned trees(p<0.05).Compared with no pruning,pruning changed the seasonal variation in NSC concentration.The orders of SS and TNC concentrations in aboveground organs were leaf>branch>trunk,while the order of ST concentration was trunk>leaf>branch,which was related to functional differences of plant organs.The annual average growth in height of unpruned,moderately pruned,and severely pruned poplars was 0.21±0.06,0.45±0.09 and 0.24±0.05 m,respectively,and the annual average growth in DBH were 0.92±0.04,1.27±0.06 and 1.02±0.05 cm,respectively.Our results demonstrate that moderate pruning may effectively increase the annual growth in tree height and DBH while avoiding damage caused by excessive pruning to the tree body.Therefore,moderate pruning may increase the NSC storage and improve the growth of timber species.展开更多
文摘Objective:To evaluate the sensitivity pattern of bacterial pathogens in the intensive care unit(ICU) of a tertiary care of Falmawati Hospital Jakarta Indonesia.Methods:A cross sectional retrospective study of bacterial pathogen was carried out on a total of 722 patients that were admitted to the ICU of Fatmawati Hospital Jakarta Indonesia during January 2009 to March 2010. All bacteria were identified by standard microbiologic methods,and(heir antibiotic susceptibility testing was performed using disk diffusion method.Results:Specimens were collected from 385 patients who were given antimicrobial treatment,of which 249(64.68%) were cultured positive and 136(35.32%) were negative.The most predominant isolate was Pseudomonas aeruginosa(P.aeruginosa)(26.5%) followed by Klebsiella pneumoniae(K.pneumoniae)(15.3%) and Staphylococcus epidermidis(14.9%).P.aeruginosa isolates showed high rate of resistance to cephalexin(95.3%),cefotaxime(64.1%),and ceftriaxone(60.9%).Amikacin was the most effective(84.4%) antibiotic against P.aeruginosa followed by imipenem(81.2%),and meropenem(75.0%).K.pneumoniae showed resistance to cephalexin(86.5%),ceftriaxone(75.7%),ceftazidime(73.0%),cefpirome(73.0%) and cefotaxime(67.9%),respectively.Conclusions:Most bacteria isolated from ICU of Fatmawati Hospital Jakarta Indonesia were resistant to the third generation of cephalosporins,and quinolone antibiotics.Regular surveillance of antibiotic susceptibility pallerns is very important for setting orders to guide the clinician in choosing empirical or directed therapy of infected patients.
基金supported by grants from the Key Laboratory Construction Project of Guangzhou City,China (121800085)the Health & Medical Collaborative Innovation Project of Guangzhou City,China (201400000001)+2 种基金the National Science & Technology Pillar Program during the Twelfth Five-year Plan Period (2014BAI09B10)the National Natural Science Foundation of China (81201746)the Planned Science and Technology Project of Guangdong Province,China (2013B020400004)
文摘Background: The prognostic values of staging parameters require continual re?assessment amid changes in diag?nostic and therapeutic methods. This study aimed to identify the prognostic factors and failure patterns of non?meta?static nasopharyngeal carcinoma(NPC) in the intensity?modulated radiotherapy(IMRT) era.Methods: We reviewed the data from 749 patients with newly diagnosed, biopsy?proven, non?metastatic NPC in our cancer center(South China, an NPC endemic area) between January 2003 and December 2007. All patients under?went magnetic resonance imaging(MRI) before receiving IMRT. The actuarial survival rates were estimated using the Kaplan–Meier method, and survival curves were compared using the log?rank test. Multivariate analyses with the Cox proportional hazards model were used to test for the independent prognostic factors by backward eliminating insigniicant explanatory variables.Results: The 5?year occurrence rates of local failure, regional failure, locoregional failure, and distant failure were 5.4, 3.0, 7.4, and 17.4%, respectively. The 5?year survival rates were as follows: local relapse?free survival, 94.6%; nodal relapse?free survival, 97.0%; distant metastasis?free survival, 82.6%; disease?free survival, 75.1%; and overall survival, 82.0%. Multivariate Cox regression analysis revealed that orbit involvement was the only signiicant prognostic fac?tor for local failure(P = 0.011). Parapharyngeal tumor extension, retropharyngeal lymph node involvement, and the laterality, longest diameter, and Ho's location of the cervical lymph nodes were signiicant prognostic factors for both distant failure and disease failure(all P < 0.05). Intracranial extension had signiicant prognostic value for distant failure(P = 0.040).Conclusions: The key failure pattern for NPC was distant metastasis in the IMRT era. With changes in diagnostic and therapeutic technologies as well as treatment modalities, the signiicant prognostic parameters for local control have also been altered substantially.
文摘BACKGROUND Ventilator-associated pneumonia(VAP)is defined as pneumonia that occurs two calendar days following endotracheal intubation or after that.It is the most common infection encountered among intubated patients.VAP incidence showed wide variability between countries.AIM To define the VAP incidence in the intensive care unit(ICU)in the central gove-rnment hospital in Bahrain and review the risk factors and the predominant bacterial pathogens with their antimicrobial susceptibility pattern.METHODS The research was a prospective cross-sectional observational study over six months from November 2019 to June 2020.It included adult and adolescent patients(>14 years old)admitted to the ICU and required intubation and mechanical ventilation.VAP was diagnosed when it occurred after 48 h after endotracheal intubation using the clinical pulmonary infection score,which considers the clinical,laboratory,microbiological,and radiographic evidence.RESULTS The total number of adult patients admitted to the ICU who required intubation and mechanical ventilation during the study period was 155.Forty-six patients developed VAP during their ICU stay(29.7%).The calculated VAP rate was 22.14 events per 1000 ventilator days during the study period,with a mean age of 52 years±20.Most VAP cases had late-onset VAP with a mean number of ICU days before the development of VAP of 9.96±6.55.Gram-negative contributed to most VAP cases in our unit,with multidrug-resistant Acinetobacter being the most identified pathogen.CONCLUSION The reported VAP rate in our ICU was relatively high compared to the international benchmark,which should trigger a vital action plan for reinforcing the implementation of the VAP prevention bundle.
基金Project supported by the National Natural Science Foundation of China(Grant No.61702347)the Natural Science Foundation of Hebei Province,China(Grant No.F2017210161)Education Department of Hebei Province,China(Grant No.QN2017132)
文摘Speckle patterns are a fundamental tool in a variety of physical and optical applications. Here, we investigate a method of precisely tuning the intensity statistics of random speckle patterns into a desirable pattern that possesses the same spatial correlation length and similar statistics distribution. This tuning mechanism relies on the derivation of the transform function and transmission matrix, which achieves different contrasts while maintaining the same average value or energy level. The statistics properties of the generated speckle patterns are further investigated by analyzing the standard deviation under different fitting parameters. Precisely tuning the intensity statistics of random speckle patterns could be useful for both fundamental research and practical applications, such as microscopy, imaging, and optical manipulation.
文摘<strong>Background: </strong><span style="font-family:;" "=""><span style="font-family:Verdana;">An intensive care unit (ICU) is a special unit of a hospital that provides intensive treatment for patients with severe or life-threatening illnesses and injuries, which require constant care and close monitoring with life support equipment. The mortality rate is still very high in most ICUs especially in the developing countries due to late presentation of patients, unavailability of well trained staff and lack of life support equipment. There has not been any previous study on the mortality pattern in ICU of Alex Ekwueme Federal University Teaching Hospital Abakaliki (AEFUTHA). It is against this background that we embarked on this retrospective descriptive hospital based study of the mortality pattern in ICU of a Tertiary Hospital in Abakaliki, South-eastern Nigeria. </span><b><span style="font-family:Verdana;">Method: </span></b><span style="font-family:Verdana;">This is a retrospective descriptive hospital based study. The admission and discharge registers of the ICU ward were used to extract information on biodata, diagnosis, duration and outcome of all admissions from January to December 2019 (12</span></span><span style="font-family:Verdana;"> </span><span style="font-family:;" "=""><span style="font-family:Verdana;">months). </span><b><span style="font-family:Verdana;">Results: </span></b><span style="font-family:Verdana;">A total of 174 (male 113, female 71) patients were admitted over the 12</span></span><span style="font-family:Verdana;"> </span><span style="font-family:Verdana;">months period with mean age of 46.31</span><span style="font-family:Verdana;"> </span><span style="font-family:Verdana;">±</span><span style="font-family:Verdana;"> </span><span style="font-family:Verdana;">12.28</span><span style="font-family:Verdana;"> </span><span style="font-family:Verdana;">years. Seventy</span><span style="font-family:Verdana;">-</span><span style="font-family:;" "=""><span style="font-family:Verdana;">one (40.8%) of the patients died from predominantly stroke, acute abdomen, trauma, sepsis, renal failure, acute diabetic complications and cancer in descending order. Acute diabetic complications had 100% case fatality rate, followed by stroke (71%), renal failure (62.5%), cancer (60%), sepsis (55.5%), acute abdomen (34%) and trauma (23%). The mean duration of ICU admission was 4.2 days for the non-survivors and 6.3 days for survivors. </span><b><span style="font-family:Verdana;">Conclusion: </span></b><span style="font-family:Verdana;">The ICU mortality rate was high and constituted of mainly stroke, acute abdomen and trauma which are essentially preventable. Female sex, medical diagnosis and ICU admission duration of less than 6 days were associated with higher ICU mortality.</span></span>
基金supported by the Guangdong High Level Innovation Research Institute(Grant No.2021B0909050006)the National Grand Instrument Project(Grant No.2019YFF01014402)+1 种基金the National Natural Science Foundation of China(Grant No.12205008)support from the National Science Fund for Distinguished Young Scholars(Grant No.12225501)。
文摘Experimental validation of laser intensity is particularly important for the study of fundamental physics at extremely high intensities.However,reliable diagnosis of the focal spot and peak intensity faces huge challenges.In this work,we demonstrate for the firs time that the coherent radiation farfiel patterns from laser–foil interactions can serve as an in situ,real-time,and easy-to-implement diagnostic for an ultraintense laser focus.The laser-driven electron sheets,curved by the spatially varying laser fiel and leaving the targets at nearly the speed of light,produce doughnut-shaped patterns depending on the shapes of the focal spot and the absolute laser intensities.Assisted by particle-in-cell simulations,we can achieve measurements of the intensity and the focal spot,and provide immediate feedback to optimize the focal spots for extremely high intensity.
基金National Key Research and Development Program of China,No.2016YFC0503500,No.2016YFC0503700
文摘Land use intensity quantifies the impacts of human activities on natural ecosystems, which have become the major driver of global environmental change, and thus it serves as an essential measurement for assessing land use sustainability. To date, land-change studies have mainly focused on changes in land cover and their effects on ecological processes, whereas land use intensity has not yet received the attention it deserves and for which spa- tially-explicit representation studies have only just begun. In this paper, according to the de- gree and reversibility of surface disturbance by human activities, there are four main classes of land use intensity： artificial land, semi-artificial land, semi-natural land, and natural land. These were further divided into 22 subclasses based on key indicators, such as human pop- ulation density and the cropping intensity. Land use intensity map of China at a 1-km spatial resolution was obtained based on satellite images and statistical data. The area proportions of artificial land, semi-artificial land, semi-natural land, and natural land were 0.71%, 19.36%, 58.93%, and 21%, respectively. Human and economic carrying capacity increased with the increase of land use intensity. Artificial land supports 24.58% and 35.62% of the total population and GDP, using only 0.71% of the total land, while semi-artificial land supported 58.24% and 49.61% of human population and GDP with 19.36% of China＇s total land area.
基金Under the auspices of Strategic Priority Research Program of Chinese Academy of Sciences(No.XDA05130703)Knowledge Innovation Program of Chinese Academy of Sciences(No.KZCX2-YW-224)2020-Planning Project of Yantai Institute of Coastal Zone Research of Chinese Academy of Sciences(No.Y254021031-6)
文摘Based on remote sensing and GIS techniques, land use maps in 2000, 2005 and 2010 in China′s coastal zone were produced, and structural raster data of land use were further generated to calculate land use intensity comprehensive index(LUICI) for analyzing land use spatial-temporal characteristics at 1 km scale. Results show that: 1) from the perspective of spatial patterns of landforms at a macro scale, there is a significant difference in land use intensity between the north and the south of China′s coastal zone. Hotspots of changes mainly concentrated in metropolitan areas, estuaries and coastal wetlands; 2) elevation is an important factor that controlling land use spatial patterns at local scale. Land use intensity is much higher within areas below the elevation of 400 m and it decreased significantly as the elevation increasing; 3) there is a significant land-ocean gradient for land use intensity, which is low in island and near-shore areas, but high in the regions that 4–30 km far away the coastline because of much intensive human activities; however, in recent decades land use intensity had been promoted significantly in low near-shore area due to extensive sea reclamations; 4) significant differences of land use intensity were also found among provincial administrative units. A rising trend of land use intensity was found in provincial-level administrative units from 2000 to 2010. To sum up, elevation, land-ocean gradient, socio-economic status and policy are all influencing factors to the spatial patterns and temporal variations of land use intensity in China′s coastal zone.
基金The National Natural Science Foundation of China under contract No.41706034the Basic Scientific Fund for National Public Research Institutes of China under contract No.2020Q05+7 种基金the Open Fund of the Key Laboratory of Ocean Circulation and WavesChinese Academy of Sciences under contract Nos KLOCW1803 and KLOCW1804the Open Fund of the Laboratory for Regional Oceanography and Numerical ModelingQingdao National Laboratory for Marine Science and Technology under contract No.2019A02the National Natural Science Foundation of China under contract Nos 91428206 and 41376038the National Science and Technology Major Project under contract No.2016ZX05057015the National Programme on Global Change and Air-Sea Interaction under contract Nos GASI-03-01-01-02 and GASI-IPOVAI-01-05the NSFC-Shandong Joint Fund for Marine Science Research Centers under contract No.U1606405。
文摘The spatial-temporal patterns of tropical cyclone(TC) intensity changes caused by the warm ocean mesoscale eddy(WOME) distribution are evaluated using two sets of idealized numerical experiments. The results show that the TC was intensified and weakened when a WOME was close to and far away from the TC center, respectively.The area where the WOME enhanced(weakened) TC intensity is called the inner(outer) area in this study.Amplitudes of the enhancement and weakening caused by the WOME in the inner and outer area decreased and increased over time, while the ranges of the inner and outer area diminished and expanded, respectively. The WOME in the inner area strengthened the secondary circulation of the TC, increased heat fluxes, strengthened the symmetry, and weakened the outer spiral rainband, which enhanced TC intensity. The effect was opposite if the WOME was in the outer area, and it weakened the TC intensity. The idealized simulation employed a stationary TC, and thus the results may only be applied to TCs with slow propagation. These findings can improve our understanding of the interactions between TC and the WOME and are helpful for improving TC intensity forecasting by considering the effect of the WOME in the outer areas.
基金part of our research program named as Urbanization o f Shandongfrom the angle of"Scientific Development"(No.04CFJ01)sponsored by Shandong Social Science Research Project.
文摘The 21st century is referred to as a"century for cities"or"era for cities"and China hasalso speeded up its process of urbanization.It is veryimportant to choose a scientific urbanization patternto exert the function of cities and realize our dreamfor China to become a powerful modernized country.It’s concluded from history since 1800 that the patternof the world urbanization has transformed from"extensive"to"intensive".However,it is still anextensive pattern in China,and there are manyproblems behind the splendid achievements,reflectedon the urbanization process of our country since1949.Today,sustainable development and theknowledge economy are the themes of the cities;itis inevitable to change our urbanization pattern.Based on the dialectic relationship of quality andquantity,the article points out that urbanizationshould not only focus on quantity but also on qualityin China.High quality and multiform urbanizationpattern is an inevitable choice of China,and thedevelopment of the region can also be exalted by theradiation of the cities.But what’s the real meaningof the new pattern?What’s its difference from thewestern countries’?The article discusses its contentaccording to the reality of China.
基金supported by Key Projects of Universities for Foreign Cultural and Educational Experts Employment Plan in 2018(T2018013)granted from Special Funds for Sustainable Development of Science and Technology Platform for Fundamental Research Business Expenses of Central Universities(2572018CP05).
文摘Although pruning is important to obtain highquality,large-diameter timber,the effects of pruning on nonstructural carbohydrates(NSC)in aboveground organs of many timber species are not well understood.Three intensities of pruning(none,moderate and severe)were tested on poplars(Populus alba×P.talassica)in the arid desert region of northwest China to compare the concentrations of soluble sugar(SS),starch(ST)and total nonstructural carbohydrate(TNC)in leaves,branches and trunks during the growing season.The concentration of NSC components after different pruning intensities varied similarly in seasonal patterns,increasing slowly at the beginning of the growing season,continuously declining in the middle,then gradually recovering by the end of the growing season.The monthly mean NSC concentration in poplar differed significantly among the three pruning intensities(p<0.05).The SS concentration in pruned trees was higher than in unpruned trees(p<0.05).For moderately pruned trees,the concentrations of ST and TNC in trunks and branches were higher than in unpruned and in severely pruned trees(p<0.05).Compared with no pruning,pruning changed the seasonal variation in NSC concentration.The orders of SS and TNC concentrations in aboveground organs were leaf>branch>trunk,while the order of ST concentration was trunk>leaf>branch,which was related to functional differences of plant organs.The annual average growth in height of unpruned,moderately pruned,and severely pruned poplars was 0.21±0.06,0.45±0.09 and 0.24±0.05 m,respectively,and the annual average growth in DBH were 0.92±0.04,1.27±0.06 and 1.02±0.05 cm,respectively.Our results demonstrate that moderate pruning may effectively increase the annual growth in tree height and DBH while avoiding damage caused by excessive pruning to the tree body.Therefore,moderate pruning may increase the NSC storage and improve the growth of timber species.
