This study analyzed the impact of the local dry and rainy seasons on diurnal temperature range (DTR), for each major climatic zone of Nigeria namely the tropical monsoon, tropical savannah and semi-arid, using meteoro...This study analyzed the impact of the local dry and rainy seasons on diurnal temperature range (DTR), for each major climatic zone of Nigeria namely the tropical monsoon, tropical savannah and semi-arid, using meteorological data from thirteen observation stations for the period 1981 to 2021. DTR was computed from the difference of minimum temperature from maximum temperature and yearly and forty one years’ monthly averages of DTR and rainfall were computed and plotted in different graphs. The overall results from each climatic zone showed that DTR fluctuates with the seasons and there is an inverse relationship between DTR and rainfall whereby the value of DTR decreases as the rainy season approaches but increases as the rainy season departs ushering in the dry season or conversely DTR increases as the dry season approaches and decreases as the dry season departs ushering-in the rainy season. Secondly, the average yearly patterns of rainfall and DTR are roughly and oppositely shaped parabolas where the peak value of rainfall is diametrically opposite to the trough value of DTR and the least or nil volume of rainfall corresponds to the highest value of DTR. Thirdly, due to the yearly seasonal cycle of dry and rainy seasons in Nigeria coupled with the inverse relationship between DTR and Rainfall, the seasonal plot of DTR and rainfall is also cyclic in pattern with DTR cycle lagging 180 degrees with the rainfall cycle and the intersection of the two cycles represents the departure of one season and onset of another season while each half-cycle represents either the dry or rainy season. Fourthly, the dependence of DTR on any season at hand in Nigeria makes DTR season-forcing. This fourth result is underpinned by a result that showed that the 1981 and 2021 patterns of DTR and 1981 and 2021 patterns of rainfall when compared were similar, the differences were in the volume of rainfall which was due to climate change that has taken place over the four decades and which also impacted DTR since DTR varies inversely with rainfall. Finally and notwithstanding the common grounds of the results stated above, the result further showed that each climatic zone of Nigeria reacts differently to the local and global climate changes leading to the magnitude of DTR and the volume of rainfall being different across climatic zones, with rainfall volume and duration decreasing towards the arid North from the Coastal South while contrariwise DTR increases towards the arid North from the Coastal South.展开更多
[ Objective] The research aimed to study seasonal dynamics of the soil moisture in Yuanmou Dry-Hot Valley of Yunnan. [ Method] We investigated soil moisture in rainy season in Yuanmou Dry-Hot Valley. By combining comp...[ Objective] The research aimed to study seasonal dynamics of the soil moisture in Yuanmou Dry-Hot Valley of Yunnan. [ Method] We investigated soil moisture in rainy season in Yuanmou Dry-Hot Valley. By combining completed research about soil moisture in dry season, data in rainy and dry seasons were contrasted to study seasonal dynamics of the soil moisture in the zone. [ Resultl Soil moisture in rainy season increased with the depth of soil, but would decrease within 1.0 m below the root layer. The soil moisture of grassland was higher than that of the woodland, while soil moisture of the savanna was higher than that of the woodland but lower than that of the grassland. In addition, compared with soil mois- ture in dry season, it is clear that to avoid forming permanent soil desiccation, based on soil and hydrology conditions in Yuanmou, it is better to plant grass not tree in Yuanmou when we do something about ecological restoration. [ Condusion] The research had certain guidance significance for planting agricultural and economic crops and carrying out ecological restoration in Yuanmou Dry-Hot Valley.展开更多
The chemical compositions of the head space,essential oil and absolute of jasmin flowers in different farming seasons during the blossom period in Fuzhou were reported in this paper.
[Objectives] To observe the clinical therapeutic efficacy of local hot-wet compress therapy of digestion ointment prescription on the patients with moderate and severe mastalgia. [Methods] Firstly,60 patients with mas...[Objectives] To observe the clinical therapeutic efficacy of local hot-wet compress therapy of digestion ointment prescription on the patients with moderate and severe mastalgia. [Methods] Firstly,60 patients with mastalgia were selected,and divided into the experimental group and control group( 30 cases for each group). The control group was treated with acupuncture at distal point,and the experimental group was treated with TCM local hot-wet compress therapy combined with acupuncture at distal point. Then,the clinical therapeutic efficacy of two groups was compared. [Results]The experimental group was superior to the control group in relieving the breast pain,improving emotional integral,reducing breast lumps,improving lump texture,and improving TCM syndrome integral( P < 0. 05). [Conclusions]The digestion ointment prescription local hot-wet compress therapy has a significant therapeutic effect on treatment of mastalgia and can significantly improve the breast pain symptom of patients.展开更多
The different drought phases observed during the 1970-2010 period have underlined important weaknesses of West African agricultural systems. The droughts resulted in important decreases in crop production, triggering ...The different drought phases observed during the 1970-2010 period have underlined important weaknesses of West African agricultural systems. The droughts resulted in important decreases in crop production, triggering a significant deficit in food availability. Many studies have identified changes in rain events seasonal patterns as the key drivers of agricultural production failure during these drought phases. In this study, seven agriculturally-relevant intra-seasonal rainfall characteristics (i.e., annual rainfall amount, onset and cessation of the rainy season, dry spells, extreme rain events, hot spells, and strong winds) and associated constraints to crop growth are described for the main cereals (maize, millet, and sorghum) in southwestern Burkina Faso. These characteristics are calculated or determined using daily climate data from a local network of 16 weather stations spanning the 1970-2013 period. A computation of the intensity and the occurrence of these phenomena during the rainy seasons helped to draw the rainy seasons’ nomenclature. Findings suggest that the rainy seasons during the drought phases are characterized by low annual rainfall amount, late onset, early cessation and more frequent long dry spells (>7 days). Furthermore, the long dry spells mostly occurred during the most sensitive phases of crop development: germination at the beginning of the rainy season and flowering at the end of the rainy season. Also, the intensity and the probability of occurrence of the other extreme events (hot spells and strong winds) during rainy seasons are very high in the establishment phase. Thus, adaptation strategies to mitigate these unfavorable climate conditions include a selection of short-cycle crop varieties combined with supplementary irrigation systems during long dry spells.展开更多
In the present paper, a total of 109 asthma patients were randomly divided into treatment group (red hot needle, n=62) and control group (conventional acupuncture, n=47). The treatment was conducted beginning from the...In the present paper, a total of 109 asthma patients were randomly divided into treatment group (red hot needle, n=62) and control group (conventional acupuncture, n=47). The treatment was conducted beginning from the first day of the first 10 day period of the Dog Days. After successive two years’ treatment, results showed that of the 62 and 47 cases in treatment and control groups, 16 and 7 were cured basically, 37 and 16 had remarkable improvement, 8 and 12 were ameliorated, 1 and 10 failed in the treatment, with the effective rate being 98.4% and 78.7% respectively, displaying that the therapeutic effect of treatment group was significantly superior to that of control group (P<0.01).展开更多
Survival, growth and immune response of the scallop, Chlamys farreri, cultured in lantern nets at five different depths (2, 5, 10, 15, and 20 m below the sea surface) were studied in Haizhou Bay during the hot season ...Survival, growth and immune response of the scallop, Chlamys farreri, cultured in lantern nets at five different depths (2, 5, 10, 15, and 20 m below the sea surface) were studied in Haizhou Bay during the hot season (summer and autumn) of 2007. Survival and growth rates were quantified bimonthly. Immune activities in hemolymph (superoxide dismutase (SOD) and acid phosphatase (ACP)) were measured to evaluate the health of scallops at the end of the study. Environmental parameters at the five depths were also monitored during the experiment. Mortalities mainly occurred during summer. Survival of scallops suspended at 15 m (78.0%) and 20 m (86.7%) was significantly higher than at 2 m (62.9%), 5 m (60.8%) or 10 m (66.8%) at the end of the study. Mean shell height grew significantly faster at 10 m (205.0 μm/d) and 20 m (236.9 μm/d) than at 2, 5 or 15 m in summer (July 9 to September 1); however, shell growth rate at 20 m was significantly lower than at the other four depths in autumn (September 2 to November 6). In contrast to summer, scallops at 5 m grew faster (262.9 μm/d) during autumn. The growth of soft tissue at different depths showed a similar trend to the shell. Growth rates of shell height and soft tissue were faster in autumn than in summer, with the exception of shell height at 20 m. SOD activity of scallops increased with depth, and ACP activity was significantly higher at 15 and 20 m than at other depths, which suggests that scallops were healthier near the bottom. Factors explaining the depth-related mortality and growth of scallops are also discussed. We conclude that the mass mortality of scallop, C. farreri, during summer can be prevented by moving the culture area to deeper water and yield can be maximized by suspending the scallops in deep water during summer and then transferring them to shallow water in autumn.展开更多
In this study, meteorological factors and snowmelt rate at an open site on sunny slope(OPS) and beneath forest canopy openness on shady slope(BFC) were measured using an automatic weather station and snow lysimeter du...In this study, meteorological factors and snowmelt rate at an open site on sunny slope(OPS) and beneath forest canopy openness on shady slope(BFC) were measured using an automatic weather station and snow lysimeter during the snowmelt period in 2009, 2010 and 2013. The energy budget over snow surface was calculated according to these meteorological datasets. The analysis results indicated that the net shortwave radiation(K) and sensible heat flux(H) were energy sources, and the latent heat flux(LVE) was energy sinks of snow surfaces at all sites. The net longwave radiation(L) was energy sink at OPS and 80% BFC, but energy source at 20% BFC. The gain of K, H, and the loss of LVE at BFC were obviously lower than those at OPS. The L was the maximum difference of energy budget between snow surface at BFC and OPS. In warm and wet years, the most important factor of the energy budget variation at OPS was air humidity and the second mostimportant factor was air temperature. However, the ground surface temperature on the sunny slope was the most important factor for L and energy budget at BFC. With the increases in forest canopy openness and the slope of adjacent terrains, the influences of ground surface temperature on the sunny slope on L and the energy budget over snow surface at BFC increased, especially when the snow cover on the sunny slope melts completely.展开更多
Extreme high temperatures occur frequently over the densely populated Yangtze River basin(YRB)in China during summer,significantly impacting the local economic development and ecological system.However,accurate predic...Extreme high temperatures occur frequently over the densely populated Yangtze River basin(YRB)in China during summer,significantly impacting the local economic development and ecological system.However,accurate prediction of extreme high-temperature days in this region remains a challenge.Unfortunately,the Climate Forecast System Version 2(CFSv2)exhibits poor performance in this regard.Thus,based on the interannual increment approach,we develop a hybrid seasonal prediction model over the YRB(HM_(YRB))to improve the prediction of extreme high-temperature days in summer.The HM_(YRB)relies on the following four predictors:the observed preceding April-May snowmelt in north western Europe;the snow depth in March over the central Siberian Plateau;the CFSv2-forecasted concurrent summer sea surface temperatures around the Maritime Continent;and the 200-hPa geopotential height over the Tibetan Plateau.The HM_(YRB)indicates good capabilities in predicting the interannual variability and trend of extreme high-temperature days,with a markable correlation coefficient of 0.58 and a percentage of the same sign(PSS)of 76% during 1983-2015 in the one-year-out cross-validation.Additionally,the HM_(YRB) maintains high PSS skill(86%)and robustness in the independent prediction period(2016-2022).Furthermore,the HM_(YRB) shows a good performance for years with high occurrence of extreme high-temperature days,with a hit ratio of 40%.These predictors used in HM_(YRB)are beneficial in terms of the prediction skill for the average daily maximum temperature in summer over the YRB,albeit with biases existing in the magnitude.Our study provides promising insights into the prediction of 2022-like hot extremes over the YRB in China.展开更多
Uses of the Buys-Ballot table for choice of appropriate transformation (using the Bartlett technique), assessment of trend and seasonal components and choice of model for time series decomposition are discussed in thi...Uses of the Buys-Ballot table for choice of appropriate transformation (using the Bartlett technique), assessment of trend and seasonal components and choice of model for time series decomposition are discussed in this paper. Uses discussed are illustrated with numerical examples when trend curve is linear, quadratic and exponential.展开更多
Sewage introduction into rivers has altered the physical and chemical properties of waters and also the microbial metabolism. This study aimed to evaluate the Escherichia coli and nutrient concentrations in the Maratu...Sewage introduction into rivers has altered the physical and chemical properties of waters and also the microbial metabolism. This study aimed to evaluate the Escherichia coli and nutrient concentrations in the Maratuãand Crumaú rivers (Santos Estuary, Brazil) during two periods with distinct magnitudes of freshwater runoff, verifying possible relation of abiotic changes with the microbial metabolism. Water sampling was performed in October/2012 (dry season) and January/2013 (rainy season) at two points in the Crumaú river (upstream and downstream zone) and one in the Maratuãriver (downstream zone). The water subsamples were obtained for E. coli and nutrient analyses while the velocity of water flow, water level, temperature, salinity, and dissolved oxygen were measured in situ. The E. coli concentrations were under the detection limit in the Maratuãdownstream during the dry season reaching a maximum value (1.47 × 10<sup>4</sup> CFU/100mL) in the Crumaú upstream during the rainy season. E. coli presented strong positive correlation with nutrients (ammoniacal-N and phosphate), evidencing the sewage source in the Crumaú upstream shown by this association. In both periods, the low oxygen saturation (100 μmol·L<sup>-1</sup>) indicated considerable predominance of heterotrophic metabolism in the Crumaú upstream. The low dissolved oxygen values in Crumaú River are corroborated to show a low self-depuration capacity in the rainy period due to maintenance of high nutrient and E. coli at two points in the Crumaú river (upstream and downstream zone) and one in the Maratuãriver (downstream zone). Besides, these results evidenced that the tendency of the metabolism changed from autotrophic to heterotrophic under high river flow events at this studied estuarine sector located at Santos estuarine complex.展开更多
Since the outbreak of the COVID-19,China's economy has been hit hard.Because of the pandemic,the overall employment situation this year is particularly grim,especially for fresh graduates.The demand of enterprises...Since the outbreak of the COVID-19,China's economy has been hit hard.Because of the pandemic,the overall employment situation this year is particularly grim,especially for fresh graduates.The demand of enterprises for graduates has decreased by 22%compared with the previous year in the same period.展开更多
[Objective] The aim was to analyze changing characters of four seasons in Jiyang, providing references for farming and disaster prevention in the area. [Methed] Changing characters of initial time and lasting periods ...[Objective] The aim was to analyze changing characters of four seasons in Jiyang, providing references for farming and disaster prevention in the area. [Methed] Changing characters of initial time and lasting periods of four seasons in Jiyang for 30 years were analyzed from meteorological standpoint with weather information from 1981 to 2010 observed in surface meteorological observation in Jiyang. [Result] Recent 30 years, initial time of spring and winter in Jiyang were earlier than before, especially for spring. In contrast, initial time of summer and autumn were later, especially for autumn. In addition, periods of spring and winter declined and the latter changed more significantly. Meanwhile, periods of summer and autumn extended and rate of linear trend for summer period was 0.042 hou/year. [Conclusion] The research indicated that lasting days of summer extended significantly and of spring and winter shortened under the background of global warming.展开更多
In this paper, a class of chemostat systems with simulate seasons Environment in the following form =(1+be(t)-s)Q+x(msa+s-k) =x(msa+s-k)-Qxis discussed. It is abstained that the system has not periodic solution when b...In this paper, a class of chemostat systems with simulate seasons Environment in the following form =(1+be(t)-s)Q+x(msa+s-k) =x(msa+s-k)-Qxis discussed. It is abstained that the system has not periodic solution when b=0; if b≠0 and b1 then system has 2 π periodic solution of system. globally asymptotically stable as mQ<μ *-1 and is unstable as mQ>μ *-1 and there exists at last one minimal 2 π periodic solution (s(t),x(t)) with \{x(t)>0,\}0<s(t)<s *(t).展开更多
Carbohydrate represents an important part of the soil labile organic carbon pool. Water soluble carbohydrate drives the C cycle in forest soil by affecting microbial activity and hot water extractable car- bohydrate i...Carbohydrate represents an important part of the soil labile organic carbon pool. Water soluble carbohydrate drives the C cycle in forest soil by affecting microbial activity and hot water extractable car- bohydrate is thought related to soil carbon sequestration due to the asso- ciation with soil aggregation. In a temperate forest region of northeast China, Changbai Mountain, we investigated the abundance, spatial dis- tribution, and seasonal dynamics of cool and hot-water extractable car- bohydrate in soils under mixed broad-leaved Korean pine forest. The concentrations of cool-water extractable carbohydrate (CWECH) in three soil layers (0-5, 5-10, 10-20 cm) ranged from 4.1 to 193.3 g.kg-1 dry soil, decreasing rapidly with soil depth. On an annual average, the CWECH concentrations in soils at depths of 5-10 and 10-20 cm were 54.2% and 24.0%, respectively, of that in the 0-5 cm soil layer. CWECH showed distinct seasonal dynamics with the highest concentrations in early spring, lowest in summer, and increasing concentrations in autumn. Hot-water extractable carbohydrate (HWECH) concentrations in three soil layers ranged from 121.4 to 2026.2 g.kgq dry soil, which were about one order of magnitude higher than CWECH. The abundance of HWECH was even more profile-dependent than CWECH, and decreased more rapidly with soil depth. On an annual average, the HWECH concentration in soils 10-20 cm deep was about one order of magnitude lower than that in the top 0-5 cm soil. The seasonality of HWECH roughly tracked that of CWECH but with seasonal fluctuations of smaller amplitude. The car- bohydrate concentrations in cool/hot water extracts of soil were positively correlated with UV254 and UV2s0 of the same solution, which has implications for predicting the leaching loss of water soluble organic carbon.展开更多
To better understand the seasonal characteristics of urban organic aerosol(OA)in the North China Plain(NCP),PM2.5 samples in the urban atmosphere of Liaocheng were collected and analyzed.The molecular distribution of ...To better understand the seasonal characteristics of urban organic aerosol(OA)in the North China Plain(NCP),PM2.5 samples in the urban atmosphere of Liaocheng were collected and analyzed.The molecular distribution of the organic markers in the urban atmosphere of Liaocheng reveals that n-alkanes(39.3%)was the most abundant species all year round,followed by saccharides(28.2%),phthalic acids(Ph,20.8%),biogenic secondary organic aerosol(BSOA)tracers(9.4%),and polycyclic aromatic hydrocarbon(PAHs,2.3%).PM2.5,organic carbon(OC),elemental carbon(EC),and primary organic markers exhibit the highest concentrations in winter,due largely to the increased biomass burning and coal combustion for house heating in local and surrounding regions.However,the concentration and relative abundance of BSOA are significantly higher in summer than other seasons,induced by the more favorable meteoro-logical conditions that would promote the emissions of biogenic volatile organic compounds(BVOCs)and the secondary production of BSOA.The ratios of OC/EC and 3-methyl-1,2,3-butanetricarboxylic acid to cis-pinic acid plus cis-pinonic acid(MBTCA/(PA+PNA)are higher in the warm seasons than those in the cold seasons,indicating that the oxidation of OA is sensitive to air temperature.Compared to 2017,the concentration level of PAHs during wintertime decreased by 40.8%,confirming that the stringent regulation of coal burning is effective.The highest concentration of high molecular weight(HMW)n-alkanes and three anhydrosugars in winter,and the close correlation of levoglucosan with HMW n-al-kanes suggests that the impact of biomass burning was more significant in winter.The same seasonal characteristic of the ratios of high-/low-NO_(x) products with NO_(x) and the strong correlation of high-/low-NO_(x) products with levoglucosan indicate that the formation of isoprene SOA(SOA1)tracers was signif-icantly influenced by anthropogenic emissions.The molecular compositions,the distributions of fire spots,backward trajectories of air masses,and correlation analysis suggest that air pollution events in spring were primarily resulted from biomass burning and secondary oxidation,while pollution events in winter were largely driven by the increased combustion sources,and promoted aqueous secondary formation.Our results suggest that the reduction of biomass and coal combustion should be taken into account to improve the urban air quality in the NCP.展开更多
The economy is recovering in most parts of the world, which marks its entering into a post-crisis era. The financial crisis breaking out in the new century gave a heavy blow on the world's employment. As the unemp...The economy is recovering in most parts of the world, which marks its entering into a post-crisis era. The financial crisis breaking out in the new century gave a heavy blow on the world's employment. As the unemployment rate was setting a new record in America, which made Obama's approval ratings plummeting, Chinese textile graduates will make their own career decisions.展开更多
文摘This study analyzed the impact of the local dry and rainy seasons on diurnal temperature range (DTR), for each major climatic zone of Nigeria namely the tropical monsoon, tropical savannah and semi-arid, using meteorological data from thirteen observation stations for the period 1981 to 2021. DTR was computed from the difference of minimum temperature from maximum temperature and yearly and forty one years’ monthly averages of DTR and rainfall were computed and plotted in different graphs. The overall results from each climatic zone showed that DTR fluctuates with the seasons and there is an inverse relationship between DTR and rainfall whereby the value of DTR decreases as the rainy season approaches but increases as the rainy season departs ushering in the dry season or conversely DTR increases as the dry season approaches and decreases as the dry season departs ushering-in the rainy season. Secondly, the average yearly patterns of rainfall and DTR are roughly and oppositely shaped parabolas where the peak value of rainfall is diametrically opposite to the trough value of DTR and the least or nil volume of rainfall corresponds to the highest value of DTR. Thirdly, due to the yearly seasonal cycle of dry and rainy seasons in Nigeria coupled with the inverse relationship between DTR and Rainfall, the seasonal plot of DTR and rainfall is also cyclic in pattern with DTR cycle lagging 180 degrees with the rainfall cycle and the intersection of the two cycles represents the departure of one season and onset of another season while each half-cycle represents either the dry or rainy season. Fourthly, the dependence of DTR on any season at hand in Nigeria makes DTR season-forcing. This fourth result is underpinned by a result that showed that the 1981 and 2021 patterns of DTR and 1981 and 2021 patterns of rainfall when compared were similar, the differences were in the volume of rainfall which was due to climate change that has taken place over the four decades and which also impacted DTR since DTR varies inversely with rainfall. Finally and notwithstanding the common grounds of the results stated above, the result further showed that each climatic zone of Nigeria reacts differently to the local and global climate changes leading to the magnitude of DTR and the volume of rainfall being different across climatic zones, with rainfall volume and duration decreasing towards the arid North from the Coastal South while contrariwise DTR increases towards the arid North from the Coastal South.
基金Supported by National Natural Science Fund Project, China(30860053,31260111)Key Project of the Basic Research in Yunnan Province,China (2009CC003)
文摘[ Objective] The research aimed to study seasonal dynamics of the soil moisture in Yuanmou Dry-Hot Valley of Yunnan. [ Method] We investigated soil moisture in rainy season in Yuanmou Dry-Hot Valley. By combining completed research about soil moisture in dry season, data in rainy and dry seasons were contrasted to study seasonal dynamics of the soil moisture in the zone. [ Resultl Soil moisture in rainy season increased with the depth of soil, but would decrease within 1.0 m below the root layer. The soil moisture of grassland was higher than that of the woodland, while soil moisture of the savanna was higher than that of the woodland but lower than that of the grassland. In addition, compared with soil mois- ture in dry season, it is clear that to avoid forming permanent soil desiccation, based on soil and hydrology conditions in Yuanmou, it is better to plant grass not tree in Yuanmou when we do something about ecological restoration. [ Condusion] The research had certain guidance significance for planting agricultural and economic crops and carrying out ecological restoration in Yuanmou Dry-Hot Valley.
文摘The chemical compositions of the head space,essential oil and absolute of jasmin flowers in different farming seasons during the blossom period in Fuzhou were reported in this paper.
基金Supported by Basic Scientific Research Project of Beijing University of Chinese Medicine(2015-JYB-XS166)Project of National Natural Science Foundation(3157397)+2 种基金Project of Beijing Natural Science Foundation(7162082)Beijing TCM Science and Technology Development Fund Project(JJ2015-13)Beijing Municipal Health System High-level Health Technology Talents Training Program(2015-3-113)
文摘[Objectives] To observe the clinical therapeutic efficacy of local hot-wet compress therapy of digestion ointment prescription on the patients with moderate and severe mastalgia. [Methods] Firstly,60 patients with mastalgia were selected,and divided into the experimental group and control group( 30 cases for each group). The control group was treated with acupuncture at distal point,and the experimental group was treated with TCM local hot-wet compress therapy combined with acupuncture at distal point. Then,the clinical therapeutic efficacy of two groups was compared. [Results]The experimental group was superior to the control group in relieving the breast pain,improving emotional integral,reducing breast lumps,improving lump texture,and improving TCM syndrome integral( P < 0. 05). [Conclusions]The digestion ointment prescription local hot-wet compress therapy has a significant therapeutic effect on treatment of mastalgia and can significantly improve the breast pain symptom of patients.
文摘The different drought phases observed during the 1970-2010 period have underlined important weaknesses of West African agricultural systems. The droughts resulted in important decreases in crop production, triggering a significant deficit in food availability. Many studies have identified changes in rain events seasonal patterns as the key drivers of agricultural production failure during these drought phases. In this study, seven agriculturally-relevant intra-seasonal rainfall characteristics (i.e., annual rainfall amount, onset and cessation of the rainy season, dry spells, extreme rain events, hot spells, and strong winds) and associated constraints to crop growth are described for the main cereals (maize, millet, and sorghum) in southwestern Burkina Faso. These characteristics are calculated or determined using daily climate data from a local network of 16 weather stations spanning the 1970-2013 period. A computation of the intensity and the occurrence of these phenomena during the rainy seasons helped to draw the rainy seasons’ nomenclature. Findings suggest that the rainy seasons during the drought phases are characterized by low annual rainfall amount, late onset, early cessation and more frequent long dry spells (>7 days). Furthermore, the long dry spells mostly occurred during the most sensitive phases of crop development: germination at the beginning of the rainy season and flowering at the end of the rainy season. Also, the intensity and the probability of occurrence of the other extreme events (hot spells and strong winds) during rainy seasons are very high in the establishment phase. Thus, adaptation strategies to mitigate these unfavorable climate conditions include a selection of short-cycle crop varieties combined with supplementary irrigation systems during long dry spells.
文摘In the present paper, a total of 109 asthma patients were randomly divided into treatment group (red hot needle, n=62) and control group (conventional acupuncture, n=47). The treatment was conducted beginning from the first day of the first 10 day period of the Dog Days. After successive two years’ treatment, results showed that of the 62 and 47 cases in treatment and control groups, 16 and 7 were cured basically, 37 and 16 had remarkable improvement, 8 and 12 were ameliorated, 1 and 10 failed in the treatment, with the effective rate being 98.4% and 78.7% respectively, displaying that the therapeutic effect of treatment group was significantly superior to that of control group (P<0.01).
基金Supported by the National Key Technology R&D Program (No. 2006BAD09A02)the High Technology Research and Development Program of China (863 Program) (Nos. 2006AA100304, 2006AA100307)the Knowledge Innovation Program of Chinese Academy of Sciences (No. KZCX2-YW-Q07-03)
文摘Survival, growth and immune response of the scallop, Chlamys farreri, cultured in lantern nets at five different depths (2, 5, 10, 15, and 20 m below the sea surface) were studied in Haizhou Bay during the hot season (summer and autumn) of 2007. Survival and growth rates were quantified bimonthly. Immune activities in hemolymph (superoxide dismutase (SOD) and acid phosphatase (ACP)) were measured to evaluate the health of scallops at the end of the study. Environmental parameters at the five depths were also monitored during the experiment. Mortalities mainly occurred during summer. Survival of scallops suspended at 15 m (78.0%) and 20 m (86.7%) was significantly higher than at 2 m (62.9%), 5 m (60.8%) or 10 m (66.8%) at the end of the study. Mean shell height grew significantly faster at 10 m (205.0 μm/d) and 20 m (236.9 μm/d) than at 2, 5 or 15 m in summer (July 9 to September 1); however, shell growth rate at 20 m was significantly lower than at the other four depths in autumn (September 2 to November 6). In contrast to summer, scallops at 5 m grew faster (262.9 μm/d) during autumn. The growth of soft tissue at different depths showed a similar trend to the shell. Growth rates of shell height and soft tissue were faster in autumn than in summer, with the exception of shell height at 20 m. SOD activity of scallops increased with depth, and ACP activity was significantly higher at 15 and 20 m than at other depths, which suggests that scallops were healthier near the bottom. Factors explaining the depth-related mortality and growth of scallops are also discussed. We conclude that the mass mortality of scallop, C. farreri, during summer can be prevented by moving the culture area to deeper water and yield can be maximized by suspending the scallops in deep water during summer and then transferring them to shallow water in autumn.
基金funded by the National Natural Science Foundation of China (41271098, 41171066)the National Key Technology Research and Development Program of the Ministry of Science and Technology of China (2012BAC23B01)
文摘In this study, meteorological factors and snowmelt rate at an open site on sunny slope(OPS) and beneath forest canopy openness on shady slope(BFC) were measured using an automatic weather station and snow lysimeter during the snowmelt period in 2009, 2010 and 2013. The energy budget over snow surface was calculated according to these meteorological datasets. The analysis results indicated that the net shortwave radiation(K) and sensible heat flux(H) were energy sources, and the latent heat flux(LVE) was energy sinks of snow surfaces at all sites. The net longwave radiation(L) was energy sink at OPS and 80% BFC, but energy source at 20% BFC. The gain of K, H, and the loss of LVE at BFC were obviously lower than those at OPS. The L was the maximum difference of energy budget between snow surface at BFC and OPS. In warm and wet years, the most important factor of the energy budget variation at OPS was air humidity and the second mostimportant factor was air temperature. However, the ground surface temperature on the sunny slope was the most important factor for L and energy budget at BFC. With the increases in forest canopy openness and the slope of adjacent terrains, the influences of ground surface temperature on the sunny slope on L and the energy budget over snow surface at BFC increased, especially when the snow cover on the sunny slope melts completely.
基金supported by the National Key R&D Program of China(Grant No.2022YFF0801604)。
文摘Extreme high temperatures occur frequently over the densely populated Yangtze River basin(YRB)in China during summer,significantly impacting the local economic development and ecological system.However,accurate prediction of extreme high-temperature days in this region remains a challenge.Unfortunately,the Climate Forecast System Version 2(CFSv2)exhibits poor performance in this regard.Thus,based on the interannual increment approach,we develop a hybrid seasonal prediction model over the YRB(HM_(YRB))to improve the prediction of extreme high-temperature days in summer.The HM_(YRB)relies on the following four predictors:the observed preceding April-May snowmelt in north western Europe;the snow depth in March over the central Siberian Plateau;the CFSv2-forecasted concurrent summer sea surface temperatures around the Maritime Continent;and the 200-hPa geopotential height over the Tibetan Plateau.The HM_(YRB)indicates good capabilities in predicting the interannual variability and trend of extreme high-temperature days,with a markable correlation coefficient of 0.58 and a percentage of the same sign(PSS)of 76% during 1983-2015 in the one-year-out cross-validation.Additionally,the HM_(YRB) maintains high PSS skill(86%)and robustness in the independent prediction period(2016-2022).Furthermore,the HM_(YRB) shows a good performance for years with high occurrence of extreme high-temperature days,with a hit ratio of 40%.These predictors used in HM_(YRB)are beneficial in terms of the prediction skill for the average daily maximum temperature in summer over the YRB,albeit with biases existing in the magnitude.Our study provides promising insights into the prediction of 2022-like hot extremes over the YRB in China.
文摘Uses of the Buys-Ballot table for choice of appropriate transformation (using the Bartlett technique), assessment of trend and seasonal components and choice of model for time series decomposition are discussed in this paper. Uses discussed are illustrated with numerical examples when trend curve is linear, quadratic and exponential.
文摘Sewage introduction into rivers has altered the physical and chemical properties of waters and also the microbial metabolism. This study aimed to evaluate the Escherichia coli and nutrient concentrations in the Maratuãand Crumaú rivers (Santos Estuary, Brazil) during two periods with distinct magnitudes of freshwater runoff, verifying possible relation of abiotic changes with the microbial metabolism. Water sampling was performed in October/2012 (dry season) and January/2013 (rainy season) at two points in the Crumaú river (upstream and downstream zone) and one in the Maratuãriver (downstream zone). The water subsamples were obtained for E. coli and nutrient analyses while the velocity of water flow, water level, temperature, salinity, and dissolved oxygen were measured in situ. The E. coli concentrations were under the detection limit in the Maratuãdownstream during the dry season reaching a maximum value (1.47 × 10<sup>4</sup> CFU/100mL) in the Crumaú upstream during the rainy season. E. coli presented strong positive correlation with nutrients (ammoniacal-N and phosphate), evidencing the sewage source in the Crumaú upstream shown by this association. In both periods, the low oxygen saturation (100 μmol·L<sup>-1</sup>) indicated considerable predominance of heterotrophic metabolism in the Crumaú upstream. The low dissolved oxygen values in Crumaú River are corroborated to show a low self-depuration capacity in the rainy period due to maintenance of high nutrient and E. coli at two points in the Crumaú river (upstream and downstream zone) and one in the Maratuãriver (downstream zone). Besides, these results evidenced that the tendency of the metabolism changed from autotrophic to heterotrophic under high river flow events at this studied estuarine sector located at Santos estuarine complex.
文摘Since the outbreak of the COVID-19,China's economy has been hit hard.Because of the pandemic,the overall employment situation this year is particularly grim,especially for fresh graduates.The demand of enterprises for graduates has decreased by 22%compared with the previous year in the same period.
基金Supported by Research Project for Season Change in Jinan Region~~
文摘[Objective] The aim was to analyze changing characters of four seasons in Jiyang, providing references for farming and disaster prevention in the area. [Methed] Changing characters of initial time and lasting periods of four seasons in Jiyang for 30 years were analyzed from meteorological standpoint with weather information from 1981 to 2010 observed in surface meteorological observation in Jiyang. [Result] Recent 30 years, initial time of spring and winter in Jiyang were earlier than before, especially for spring. In contrast, initial time of summer and autumn were later, especially for autumn. In addition, periods of spring and winter declined and the latter changed more significantly. Meanwhile, periods of summer and autumn extended and rate of linear trend for summer period was 0.042 hou/year. [Conclusion] The research indicated that lasting days of summer extended significantly and of spring and winter shortened under the background of global warming.
文摘In this paper, a class of chemostat systems with simulate seasons Environment in the following form =(1+be(t)-s)Q+x(msa+s-k) =x(msa+s-k)-Qxis discussed. It is abstained that the system has not periodic solution when b=0; if b≠0 and b1 then system has 2 π periodic solution of system. globally asymptotically stable as mQ<μ *-1 and is unstable as mQ>μ *-1 and there exists at last one minimal 2 π periodic solution (s(t),x(t)) with \{x(t)>0,\}0<s(t)<s *(t).
基金supported by made possible through National Key Basic Research Foundation, China (grants 2011CB403202)the National Natural Science Foundation of China (40930107)Program for Changjiang Scholars and Innovative Research Team in University (IRT1054)
文摘Carbohydrate represents an important part of the soil labile organic carbon pool. Water soluble carbohydrate drives the C cycle in forest soil by affecting microbial activity and hot water extractable car- bohydrate is thought related to soil carbon sequestration due to the asso- ciation with soil aggregation. In a temperate forest region of northeast China, Changbai Mountain, we investigated the abundance, spatial dis- tribution, and seasonal dynamics of cool and hot-water extractable car- bohydrate in soils under mixed broad-leaved Korean pine forest. The concentrations of cool-water extractable carbohydrate (CWECH) in three soil layers (0-5, 5-10, 10-20 cm) ranged from 4.1 to 193.3 g.kg-1 dry soil, decreasing rapidly with soil depth. On an annual average, the CWECH concentrations in soils at depths of 5-10 and 10-20 cm were 54.2% and 24.0%, respectively, of that in the 0-5 cm soil layer. CWECH showed distinct seasonal dynamics with the highest concentrations in early spring, lowest in summer, and increasing concentrations in autumn. Hot-water extractable carbohydrate (HWECH) concentrations in three soil layers ranged from 121.4 to 2026.2 g.kgq dry soil, which were about one order of magnitude higher than CWECH. The abundance of HWECH was even more profile-dependent than CWECH, and decreased more rapidly with soil depth. On an annual average, the HWECH concentration in soils 10-20 cm deep was about one order of magnitude lower than that in the top 0-5 cm soil. The seasonality of HWECH roughly tracked that of CWECH but with seasonal fluctuations of smaller amplitude. The car- bohydrate concentrations in cool/hot water extracts of soil were positively correlated with UV254 and UV2s0 of the same solution, which has implications for predicting the leaching loss of water soluble organic carbon.
基金supported by the National Natural Science Foundation of China(Grant No.42177083)the Natural Science Foundation of Shandong Province(Grant No.ZR2020MD113)the Open Funds of State Key Laboratory of Loess and Quaternary Geology,Institute of Earth Environment,Chinese Academy of Sciences(Grant No.SKLLOG 2020).
文摘To better understand the seasonal characteristics of urban organic aerosol(OA)in the North China Plain(NCP),PM2.5 samples in the urban atmosphere of Liaocheng were collected and analyzed.The molecular distribution of the organic markers in the urban atmosphere of Liaocheng reveals that n-alkanes(39.3%)was the most abundant species all year round,followed by saccharides(28.2%),phthalic acids(Ph,20.8%),biogenic secondary organic aerosol(BSOA)tracers(9.4%),and polycyclic aromatic hydrocarbon(PAHs,2.3%).PM2.5,organic carbon(OC),elemental carbon(EC),and primary organic markers exhibit the highest concentrations in winter,due largely to the increased biomass burning and coal combustion for house heating in local and surrounding regions.However,the concentration and relative abundance of BSOA are significantly higher in summer than other seasons,induced by the more favorable meteoro-logical conditions that would promote the emissions of biogenic volatile organic compounds(BVOCs)and the secondary production of BSOA.The ratios of OC/EC and 3-methyl-1,2,3-butanetricarboxylic acid to cis-pinic acid plus cis-pinonic acid(MBTCA/(PA+PNA)are higher in the warm seasons than those in the cold seasons,indicating that the oxidation of OA is sensitive to air temperature.Compared to 2017,the concentration level of PAHs during wintertime decreased by 40.8%,confirming that the stringent regulation of coal burning is effective.The highest concentration of high molecular weight(HMW)n-alkanes and three anhydrosugars in winter,and the close correlation of levoglucosan with HMW n-al-kanes suggests that the impact of biomass burning was more significant in winter.The same seasonal characteristic of the ratios of high-/low-NO_(x) products with NO_(x) and the strong correlation of high-/low-NO_(x) products with levoglucosan indicate that the formation of isoprene SOA(SOA1)tracers was signif-icantly influenced by anthropogenic emissions.The molecular compositions,the distributions of fire spots,backward trajectories of air masses,and correlation analysis suggest that air pollution events in spring were primarily resulted from biomass burning and secondary oxidation,while pollution events in winter were largely driven by the increased combustion sources,and promoted aqueous secondary formation.Our results suggest that the reduction of biomass and coal combustion should be taken into account to improve the urban air quality in the NCP.
文摘The economy is recovering in most parts of the world, which marks its entering into a post-crisis era. The financial crisis breaking out in the new century gave a heavy blow on the world's employment. As the unemployment rate was setting a new record in America, which made Obama's approval ratings plummeting, Chinese textile graduates will make their own career decisions.