12%difenoconazole+fluxapyroxad SC(commercial name:Jiangong)was first released by BASF in China in 2016.It has been registered to control many diseases,including pear scab,apple Alternaria leaf spot,tomato early blight...12%difenoconazole+fluxapyroxad SC(commercial name:Jiangong)was first released by BASF in China in 2016.It has been registered to control many diseases,including pear scab,apple Alternaria leaf spot,tomato early blight,cucumber powdery mildew,etc.This study evaluated the bioactivity of Jiangong against Alternaria alternata and explored variations of phyllosphere microorganisms in both asymptomatic and tobacco brown spot leaves at different persistence periods(0,5,10,and 15 days post-fungicide application)using high-throughput sequencing technology.The results indicated that Jiangong effectively inhibited mycelial growth(average EC_(50) value of 0.51μg/mL),conidia germination(average EC_(50) value of 3.47μg/mL),and the carbon metabolism of A.alternata.Both asymptomatic and symptomatic leaves presented complex microbial communities.Higher fungal diversity was noted in asymptomatic leaves,while higher bacterial diversity was found in symptomatic leaves.After application,the diversity and abundance of microbial community structures in both types of leaves changed over time.Fungal microbiome communities showed greater sensitivity than bacterial groups,with the microbiome communities of asymptomatic leaves being more affected than those of symptomatic leaves.Fungal community diversity decreased for both symptomatic and asymptomatic leaves after 5 days of application,while the diversity of fungal community in symptomatic leaves showed an upward trend after 10 days of application.Meanwhile,bacterial community diversity increased in both symptomatic and asymptomatic leaves after 5 days of application but then declined in asymptomatic leaves after 15 days.The abundance of the dominant function group of phyllosphere bacteria(metabolism,genetic information processing,environmental information processing)was not affected by the application of Jiangong.However,the abundance of the dominant function group of phyllosphere fungi(animal pathogen-endophyte-wood saprotroph,endophyte-plant pathogen,plant pathogen-undefined saprotroph)was significantly affected by the application of Jiangong,and high variation was found in symptomatic leaves than that of asymptomatic leaves.The application of Jiangong-induced alterations in the community structure of the tobacco phyllosphere microbiome provides a basis for future tobacco brown spot control strategies based on phyllospheric microecology.展开更多
Objective: To investigate the association between the mutations in lipoprotein lipase gene and hypertriglyceridemia (HTG). Methods: The lipoprotein lipase (LPL) gene was screened for mutations in 386 Chinese sub...Objective: To investigate the association between the mutations in lipoprotein lipase gene and hypertriglyceridemia (HTG). Methods: The lipoprotein lipase (LPL) gene was screened for mutations in 386 Chinese subjects with (108 cases in the HTG group) or without HTG (278 cases in the control group), by single-strand conformation polymorphism (SSCP) analysis and DNA sequencing. Results: One novel silent mutation L103L, one missense mutation P207L, three splicing mutations Int3/3' -ass/C(-6)→T, and the common S447X polymorphism has been identified in the whole coding region and exon-intron junctions of the LPL gene were examined. Heterozygous P207L found in the HTG group was the first case reported in Asia and subsequently another P207L heterozygote was found in the proband's family, all of which suggested that P207L was one of the causes of familial combined hyperlipidemia, but was not so prevalent as that in French Canadian. Int3/3'-ass/C(-6)→T was found in both groups in the present study although it was regarded as a pathogenic variant to HTG earlier on. Moreover about the beneficial polymorphism S447X, there was also some supportive evidence that the levels of triglycerides (TG) in S447X carriers were significantly lower than noncarders in the subjects without HTG. Conclusions: The association between the LPL variants and HTG is quite complicated and versatile, genotyping of LPL in a larger-scale screening should be necessary and justifiable.展开更多
To screen the high efficient mixed culture and understand the bioleaching behaviors of mixed culture for low-grade copper sulfide ore bioleaching,ten mixed cultures were collected and screened from different acid mine...To screen the high efficient mixed culture and understand the bioleaching behaviors of mixed culture for low-grade copper sulfide ore bioleaching,ten mixed cultures were collected and screened from different acid mine drainages obtained from sulfide mines of China.The leaching rate was set as criterion to screen the mixed culture and the metagenomic approach.Community genome array(CGA) was used for analyzing the mixed culture microbial community shift during the bioleaching process.The results indicate that the mixed culture obtained from Yinshan(YS) lead-zinc mine in Dexing of Jiangxi province in China reaches the maximum copper extraction(68.89%) during the one bioleaching period of 24 d.CGA results show that YS culture contains nine kinds of bacteria which are belong to six divisions,and the microbial community structure is changing during the bioleaching process.This provides a good way to accelerate the bioleaching process and reveals the microbial community shift during the bioleaching process.展开更多
The increase of atmospheric CO 2 concentration is indisputable. In such condition, photosynthetic response of leaf is relatively well studied, while the comparison of that between single leaf and whole canopy is less...The increase of atmospheric CO 2 concentration is indisputable. In such condition, photosynthetic response of leaf is relatively well studied, while the comparison of that between single leaf and whole canopy is less emphasized. The stimulation of elevated CO 2 on canopy photosynthesis may be different from that on single leaf level. In this study, leaf and canopy photosynthesis of rice (Oryza sativa L.) were studied throughout the growing season. High CO 2 and temperature had a synergetic stimulation on single leaf photosynthetic rate until grain filling. Photosynthesis of leaf was stimulated by high CO 2, although the stimulation was decreased by higher temperature at grain filling stage. On the other hand, the simulation of elevated CO 2 on canopy photosynthesis leveled off with time. Stimulation at canopy level disappeared by grain filling stage in both temperature treatments. Green leaf area index was not significantly affected by CO 2 at maturity, but greater in plants grown at higher temperature. Leaf nitrogen content decreased with the increase of CO 2 concentration although it was not statistically significant at maturity. Canopy respiration rate increased at flowering stage indicating higher carbon loss. Shading effect caused by leaf development reached maximum at flowering stage. The CO 2 stimulation on photosynthesis was greater in single leaf than in canopy. Since enhanced CO 2 significantly increased biomass of rice stems and panicles, increase in canopy respiration caused diminishment of CO 2 stimulation in canopy net photosynthesis. Leaf nitrogen in the canopy level decreased with CO 2 concentration and may eventually hasten CO 2 stimulation on canopy photosynthesis. Early senescence of canopy leaves in high CO 2 is also a possible cause.展开更多
The Himalayan Griffon(Gyps himalayensis), occurring mainly in the Tibetan Plateau, is one of the scavengers of Old World vultures. As of now, knowledge about the Himalayan Griffon in China remains scarce. Estimates of...The Himalayan Griffon(Gyps himalayensis), occurring mainly in the Tibetan Plateau, is one of the scavengers of Old World vultures. As of now, knowledge about the Himalayan Griffon in China remains scarce. Estimates of its number, habitat, and conservation status were carried out in 2003, 2009 and 2102 in the Lhasa River Valley, where we paid particular attention to the population living at the Drigung Thel Monastery, Mzizhokunggar County. The resident species occupies alpine meadows in the daytime and roosts at the upper parts of cliffs at night between 4400–5000 m elevation. The number of individual birds of the Himalayan Griffon around the monastery was estimated as 230 in 2003, 250 in 2009 and 200 in 2012. This population is considered relatively stable, thanks to the current conservation measures by Buddhist monks and local people. Given the lack of any baseline information, it is difficult for us to recommend and provide any effective conservation measures.展开更多
Aim To research on a solid cemented carbide multi facet drill for drilling high strength steel. Methods Assimilating some features of multi facet drill edge structures, through systematic drilling experiments, a n...Aim To research on a solid cemented carbide multi facet drill for drilling high strength steel. Methods Assimilating some features of multi facet drill edge structures, through systematic drilling experiments, a new type of solid cemented carbide drill was developed and the drill geometry was optimized. Results With the new type drill,the drilling force decreases by 10%-20%, the drilling productivity (drilled holes per hour) increases by 2-3 times, and the drilling precision and surface finish increase by one level. Conclusion The new type drill possesses excellent drilling performance.展开更多
We assessed habitat preference and population status of the Sichuan Jay (Perisoreus internigrans),a poorly known Chinese endemic bird,at two sites (Zhuoni and Jiuzhaigou) in the Qinghai-Tibetan plateau between 2001 an...We assessed habitat preference and population status of the Sichuan Jay (Perisoreus internigrans),a poorly known Chinese endemic bird,at two sites (Zhuoni and Jiuzhaigou) in the Qinghai-Tibetan plateau between 2001 and 2004.Mean group size was 3.8 jays.Each group occupied a mean home range of 42.0 ha during the breeding season,and the mean internest distance was 2.7 km.These data indicated that the jays used less than ten percent of the available habitats and occurred at an overall density of only 0.6 jays per km2.Radio-tracked Sichuan Jays had a strong preference for mature montane coniferous forests and avoided areas dominated by shrubs,while the utilization of young conifers,grassland,and human residential habitat types did not differ significantly from the values expected from the home-range availabilities of these habitats generally.展开更多
Various migration methods have been proposed to image high-angle geological structures and media with strong lateral velocity variations; however, the problems of low precision and high computational cost remain unres...Various migration methods have been proposed to image high-angle geological structures and media with strong lateral velocity variations; however, the problems of low precision and high computational cost remain unresolved. To describe the seismic wave propagation in media with lateral velocity variations and to image high-angle structures, we propose the generalized screen propagator based on particle swarm optimization (PSO-GSP), for the precise fitting of the single-square-root operator. We use the 2D SEG/EAGE salt model to test the proposed PSO-GSP migration method to image the faults beneath the salt dome and compare the results to those of the conventional high-order generalized screen propagator (GSP) migration and split-step Fourier (SSF) migration. Moreover, we use 2D marine data from the South China Sea to show that the PSO-GSP migration can better image strong reflectors than conventional imaging methods.展开更多
[Objective] The aim was to study the dynamic variation of extinction coefficient of corn population, so as to improve the accuracy of assessment on net primary productivity (NPP) or yield. [Method] Based on the data...[Objective] The aim was to study the dynamic variation of extinction coefficient of corn population, so as to improve the accuracy of assessment on net primary productivity (NPP) or yield. [Method] Based on the data of photosynthetic active radiation and leaf area index during corn growing season (from May to September) in 2006, observed in Jinzhou observation station of corn farmland ecosystem, China Meteorological Administration, the dynamic variation of extinction coefficient of corn population was analyzed. [Result] There was a great daily variation in the extinction coefficient of corn population during growing season, and the maximum value appeared from 7:00 to 9:00 and from 15:00 to 17:00, while the minimum could be found around 12:00, but the amplitude of variation decreased in tasseling stage. On a large time scale (5 d), there was a parabolic relationship between extinction coefficient (K) and leaf area index (LAI), with determination coefficient R2 of 0.960 7. The simulation equation of extinction coefficient, based on the sun elevation angle or leaf area index, had poor accuracy at various time during growing season, so a new dynamic model of extinction coefficient was established, namely K=λ(0.784 8-0.001 6θ)(0.154 8LAI2-0.558 6LAI+0.654). [Conclusion] The effect of sun elevation angle and leaf area index on extinction coefficient during corn growing season was considered in the new dynamic model of extinction coefficient, and its simulated result was superior to that of single-factor model.展开更多
[Objective] This study was conducted to construct a super-high yield population of Japnica rice in cold regions of North China and to explore its characteristics. [Method] The super rice variety Longjing 21 was select...[Objective] This study was conducted to construct a super-high yield population of Japnica rice in cold regions of North China and to explore its characteristics. [Method] The super rice variety Longjing 21 was selected as the experimental material. Different row spacing(two levels), plant spacing(three levels) and seedling number per hill(three levels) were designed in field trials. Then, the growth stages,dry matter accumulation, leaf area, yield and yield components of these different treatments were measured. [Result] Rice yield had significantly negative correlation with plant spacing and row spacing, but no significant correlation with seedling number per hill. Rice yield was mainly affected by plant spacing, and less affected by seedling number per hill. The best recommended specifications for plant spacing of super rice variety Longjing 21 were 24 cm for row spacing, 12 cm for plant spacing and five seedlings per hill, and the expected yield was 10 473.0 kg/hm^2.The increased number of total spikelets(4.5×108hm2or more) in populations was the major reason for high yield. Super-high yield populations had fewer tillers at the early growth stage and achieved the expected number of productive tillers at critical leaf-age(June 25), and tiller number peaked at jointing stage(July 6) and was about 1.2 times of the expected number. The percentage of productive tillers in total tillers of super-high yield population was more than 85% at heading stage. At middle growth stage(from jointing to heading stage), the dry matter accumulation, leaf area index(LAI) at heading stage, effective leaf area, spikelet number of population,spikelet number per leaf area unit(cm2), and culm-sheath weight per stem of super-high yield population were significantly higher than those of other populations.At late growth stage(from heading to maturity stage), the leaf area decreasing rate of super-high yield population was significantly smaller than that of other populations. At late growth stage(from heading to maturity stage), the leaf area decreasing rate, crop growth rate, net assimilation rate, biomass accumulation, number of filled grains per leaf area unit(cm^2) and grain weight per leaf area unit(cm^2) of high-yield population were significantly higher than those of other populations. Output and translocation of dry matter(weight per stem and sheath and total filling rate at maturity) from heading to milky stage of super-high yield population were significantly higher than those of other populations. [Conclusion] The characteristics of superhigh yield rice in cold region of North China are enriching the amount of actual filling of sink through improving photosynthetic efficiency from heading to maturity stage on the basis of enough panicle numbers.展开更多
The problems associated with vibrations of viaducts and low-frequency structural noise radiation caused by train excitation continue to increase in importance.A new floating-slab track vibration isolator-non-obstructi...The problems associated with vibrations of viaducts and low-frequency structural noise radiation caused by train excitation continue to increase in importance.A new floating-slab track vibration isolator-non-obstructive particle damping-phononic crystal vibration isolator is proposed herein,which uses the particle damping vibration absorption technology and bandgap vibration control theory.The vibration reduction performance of the NOPD-PCVI was analyzed from the perspective of vibration control.The paper explores the structure-borne noise reduction performance of the NOPD-PCVIs installed on different bridge structures under varying service conditions encountered in practical engineering applications.The load transferred to the bridge is obtained from a coupled train-FST-bridge analytical model considering the different structural parameters of bridges.The vibration responses are obtained using the finite element method,while the structural noise radiation is simulated using the frequency-domain boundary element method.Using the particle swarm optimization algorithm,the parameters of the NOPD-PCVI are optimized so that its frequency bandgap matches the dominant bridge structural noise frequency range.The noise reduction performance of the NOPD-PCVIs is compared to the steel-spring isolation under different service conditions.展开更多
Co-infection with hepatitis C virus and humanimmunodeficiency virus is common in certainpopulations. Among HCV(+) persons, 10 % are alsoHIV (+), and among HIV (+) persons, 25 % are alsoHCV(+). Many studies have shown ...Co-infection with hepatitis C virus and humanimmunodeficiency virus is common in certainpopulations. Among HCV(+) persons, 10 % are alsoHIV (+), and among HIV (+) persons, 25 % are alsoHCV(+). Many studies have shown that in intravenousdrug users, co-infection prevalence can be as high as90-95 %. There is increasing evidence supporting theconcept that people infected with HIV have a muchmore rapid course of their hepatitis C infection.Treatment of co-infection is often challenging becausehighly active anti-retroviral therapy (HAART) therapyis frequently hepatotoxic, especially in the presence ofHCV. The purpose of this review is to describe theeffects that HIV has on hepatitis C, the effects thathepatitis C has on HIV, and the treatment options inthis challenging population.展开更多
In this paper,the author study the spectrum of high rank differential operators T (n) (t) of C 0 Semigroup T(t) ,given an approach to construct the spectral set opetator T (n) (t) ,and discussed the relat...In this paper,the author study the spectrum of high rank differential operators T (n) (t) of C 0 Semigroup T(t) ,given an approach to construct the spectral set opetator T (n) (t) ,and discussed the relation between the spectral points of both T (n) (t) and infinitesimal generator A of T(t) .展开更多
Recently, the Clarkson and Kruskal direct method has been modified to find new similarity reductions (conditional similarity reductions) of nonlinear systems and the results obtained by the modified direct method cann...Recently, the Clarkson and Kruskal direct method has been modified to find new similarity reductions (conditional similarity reductions) of nonlinear systems and the results obtained by the modified direct method cannot be obtained by the current classical and/or non-classical Lie group approach. In this paper, we show that the conditional similarity reductions of the Jimbo-Miwa equation can be reobtained by adding an additional constraint equation to the original model to form a conditional equation system first and then solving the model system by means of the classical Lie group approach.展开更多
AIM: To increase attendance tor colonoscopy among nonadherent high-risk individuals for colorectal cancer (CRC) screening in China. METHODS: During the first 12 mo without intervention, only 428 of the 2398 high-r...AIM: To increase attendance tor colonoscopy among nonadherent high-risk individuals for colorectal cancer (CRC) screening in China. METHODS: During the first 12 mo without intervention, only 428 of the 2398 high-risk subjects attended a scheduled colonoscopy examination. The 1970 subjects who did not attend for CRC screening were enrolled in the present study. Prior barrier investigation was performed to ascertain the reasons for nonadherence. A barrier-focused intervention program was then established and implemented among eligible nonadherent subjects by telephone interviews and on-site consultations. The completion rates of colonoscopy during the first 12 mo without intervention and the second 12 mo with intervention were compared. Variations in the effect of the intervention on some high-risk factors and barrier characteristics were analyzed using logistic regression. RESULTS: 540 subjects who were not eligible were excluded from the study. The colonoscopy attendance rate was 23.04% (428/1858) during the first 12 mo without intervention, and 37.69% (539/1430) during the second 12 mo with intervention (P 〈 0.001). Logistic regression analysis showed that the intervention was more effective among subjects with only objective barriers (OR: 34.590, 95% CI: 23.204-51.563) or subjects with some specific highrisk characteristics: first-degree relatives diagnosed with CRC (OR: 1.778, 95% CI: 1.010-3.131), personal history of intestinal polyps (OR: 3.815, 95% CI: 1.994-7.300) and positive result for immunochemical fecal occult blood testing (OR: 2.718, 95% CI: 1.479-4.996). CONCLUSION: The barrier-focused telephone or on- site consultation intervention appears to be a feasible means to improve colonoscopy attendance among nonadherent high-risk subjects for CRC screening in China.展开更多
A systematic approach was adopted to investigate the nutrient limiting factors in gray-brown purple soils and yellow soils derived from limestone in Chongqing, China, to study balanced fertilization for corn, sweet po...A systematic approach was adopted to investigate the nutrient limiting factors in gray-brown purple soils and yellow soils derived from limestone in Chongqing, China, to study balanced fertilization for corn, sweet potato and wheat in rotation. The results showed that N, P and K were deficient in both soils, Cu, Mn, S andZn in the gray-brown purple soils and Ca, Mg, Mo and Zn for the yellow soils. Balanced fertilizer application increased yields of corn, sweet potato and wheat by 28.4%, 28.7% and 4.4%, respectively, as compared to the local farmers' practice. The systematic approach can be considered as one of the most efficient and reliable methods in fertility study.展开更多
The effects of nitrogen, phosphorus and potassium application level, seed rate and transplanting density on the growth and development of rice plants were studied to find out nutrient status in high-yielding rice plan...The effects of nitrogen, phosphorus and potassium application level, seed rate and transplanting density on the growth and development of rice plants were studied to find out nutrient status in high-yielding rice plants and to increase grain yield by adequate fertilization. There was an equilibrium relationship among nutrient elements for high-yielding rice plant populations. The equilibrium index of nutrient amount, content and distribution in high-yielding rice plants should be generally greater than-2 but less than 2. The optimum nutritive proportion of nitrogen: phosphorus: potassium assimilated by the plants was about 10: 2: 9 at the ripening stage. But the content and the proportion varied with the growth stages. Therefore, the nutrient in rice plant populations should be in a dynamic equilibrium, so as to achieve high yield.展开更多
Pancreatic cancer is difficult to diagnose at an early stage and is associated with a very poor survival.Ten percent of pancreatic cancers result from genetic susceptibility and/or familial aggregation.Individuals fro...Pancreatic cancer is difficult to diagnose at an early stage and is associated with a very poor survival.Ten percent of pancreatic cancers result from genetic susceptibility and/or familial aggregation.Individuals from families with multiple affected first-degree relatives and those with a known cancer-causing genetic mutation have been shown to be at much higher risk of developing pancreatic cancer.Recent efforts have focused on detecting disease at an earlier stage to improve survival in these high-risk groups.This article reviews high-risk groups,screening methods,and current screening programs and their results.展开更多
基金Supported by China National Tobacco Corporation[No.110202101048(LS-08)]Hundred’Level Innovative Talent Foundation of Guizhou Province(No.GCC[2022]028-1,GCC[2023]108)+2 种基金Guizhou Science Technology Foundation(No.ZK[2021]Key036)the National Natural Science Foundation of China(No.32160522)Guizhou Province Applied Technology Research and Development Funding Post-subsidy Project and Guizhou Tobacco Company(No.2020XM03,2020XM22,2024XM06).
文摘12%difenoconazole+fluxapyroxad SC(commercial name:Jiangong)was first released by BASF in China in 2016.It has been registered to control many diseases,including pear scab,apple Alternaria leaf spot,tomato early blight,cucumber powdery mildew,etc.This study evaluated the bioactivity of Jiangong against Alternaria alternata and explored variations of phyllosphere microorganisms in both asymptomatic and tobacco brown spot leaves at different persistence periods(0,5,10,and 15 days post-fungicide application)using high-throughput sequencing technology.The results indicated that Jiangong effectively inhibited mycelial growth(average EC_(50) value of 0.51μg/mL),conidia germination(average EC_(50) value of 3.47μg/mL),and the carbon metabolism of A.alternata.Both asymptomatic and symptomatic leaves presented complex microbial communities.Higher fungal diversity was noted in asymptomatic leaves,while higher bacterial diversity was found in symptomatic leaves.After application,the diversity and abundance of microbial community structures in both types of leaves changed over time.Fungal microbiome communities showed greater sensitivity than bacterial groups,with the microbiome communities of asymptomatic leaves being more affected than those of symptomatic leaves.Fungal community diversity decreased for both symptomatic and asymptomatic leaves after 5 days of application,while the diversity of fungal community in symptomatic leaves showed an upward trend after 10 days of application.Meanwhile,bacterial community diversity increased in both symptomatic and asymptomatic leaves after 5 days of application but then declined in asymptomatic leaves after 15 days.The abundance of the dominant function group of phyllosphere bacteria(metabolism,genetic information processing,environmental information processing)was not affected by the application of Jiangong.However,the abundance of the dominant function group of phyllosphere fungi(animal pathogen-endophyte-wood saprotroph,endophyte-plant pathogen,plant pathogen-undefined saprotroph)was significantly affected by the application of Jiangong,and high variation was found in symptomatic leaves than that of asymptomatic leaves.The application of Jiangong-induced alterations in the community structure of the tobacco phyllosphere microbiome provides a basis for future tobacco brown spot control strategies based on phyllospheric microecology.
基金This work was supported by the Grant from Tianjin Municipal Natural Science Foundations (No. 033607311).
文摘Objective: To investigate the association between the mutations in lipoprotein lipase gene and hypertriglyceridemia (HTG). Methods: The lipoprotein lipase (LPL) gene was screened for mutations in 386 Chinese subjects with (108 cases in the HTG group) or without HTG (278 cases in the control group), by single-strand conformation polymorphism (SSCP) analysis and DNA sequencing. Results: One novel silent mutation L103L, one missense mutation P207L, three splicing mutations Int3/3' -ass/C(-6)→T, and the common S447X polymorphism has been identified in the whole coding region and exon-intron junctions of the LPL gene were examined. Heterozygous P207L found in the HTG group was the first case reported in Asia and subsequently another P207L heterozygote was found in the proband's family, all of which suggested that P207L was one of the causes of familial combined hyperlipidemia, but was not so prevalent as that in French Canadian. Int3/3'-ass/C(-6)→T was found in both groups in the present study although it was regarded as a pathogenic variant to HTG earlier on. Moreover about the beneficial polymorphism S447X, there was also some supportive evidence that the levels of triglycerides (TG) in S447X carriers were significantly lower than noncarders in the subjects without HTG. Conclusions: The association between the LPL variants and HTG is quite complicated and versatile, genotyping of LPL in a larger-scale screening should be necessary and justifiable.
基金Project(50774102)supported by the National Natural Science Foundation of ChinaProject(2004CB619204)supported by the National Basic Research Program of China
文摘To screen the high efficient mixed culture and understand the bioleaching behaviors of mixed culture for low-grade copper sulfide ore bioleaching,ten mixed cultures were collected and screened from different acid mine drainages obtained from sulfide mines of China.The leaching rate was set as criterion to screen the mixed culture and the metagenomic approach.Community genome array(CGA) was used for analyzing the mixed culture microbial community shift during the bioleaching process.The results indicate that the mixed culture obtained from Yinshan(YS) lead-zinc mine in Dexing of Jiangxi province in China reaches the maximum copper extraction(68.89%) during the one bioleaching period of 24 d.CGA results show that YS culture contains nine kinds of bacteria which are belong to six divisions,and the microbial community structure is changing during the bioleaching process.This provides a good way to accelerate the bioleaching process and reveals the microbial community shift during the bioleaching process.
文摘The increase of atmospheric CO 2 concentration is indisputable. In such condition, photosynthetic response of leaf is relatively well studied, while the comparison of that between single leaf and whole canopy is less emphasized. The stimulation of elevated CO 2 on canopy photosynthesis may be different from that on single leaf level. In this study, leaf and canopy photosynthesis of rice (Oryza sativa L.) were studied throughout the growing season. High CO 2 and temperature had a synergetic stimulation on single leaf photosynthetic rate until grain filling. Photosynthesis of leaf was stimulated by high CO 2, although the stimulation was decreased by higher temperature at grain filling stage. On the other hand, the simulation of elevated CO 2 on canopy photosynthesis leveled off with time. Stimulation at canopy level disappeared by grain filling stage in both temperature treatments. Green leaf area index was not significantly affected by CO 2 at maturity, but greater in plants grown at higher temperature. Leaf nitrogen content decreased with the increase of CO 2 concentration although it was not statistically significant at maturity. Canopy respiration rate increased at flowering stage indicating higher carbon loss. Shading effect caused by leaf development reached maximum at flowering stage. The CO 2 stimulation on photosynthesis was greater in single leaf than in canopy. Since enhanced CO 2 significantly increased biomass of rice stems and panicles, increase in canopy respiration caused diminishment of CO 2 stimulation in canopy net photosynthesis. Leaf nitrogen in the canopy level decreased with CO 2 concentration and may eventually hasten CO 2 stimulation on canopy photosynthesis. Early senescence of canopy leaves in high CO 2 is also a possible cause.
基金the State Forestry Administration in providing financial support for this study
文摘The Himalayan Griffon(Gyps himalayensis), occurring mainly in the Tibetan Plateau, is one of the scavengers of Old World vultures. As of now, knowledge about the Himalayan Griffon in China remains scarce. Estimates of its number, habitat, and conservation status were carried out in 2003, 2009 and 2102 in the Lhasa River Valley, where we paid particular attention to the population living at the Drigung Thel Monastery, Mzizhokunggar County. The resident species occupies alpine meadows in the daytime and roosts at the upper parts of cliffs at night between 4400–5000 m elevation. The number of individual birds of the Himalayan Griffon around the monastery was estimated as 230 in 2003, 250 in 2009 and 200 in 2012. This population is considered relatively stable, thanks to the current conservation measures by Buddhist monks and local people. Given the lack of any baseline information, it is difficult for us to recommend and provide any effective conservation measures.
文摘Aim To research on a solid cemented carbide multi facet drill for drilling high strength steel. Methods Assimilating some features of multi facet drill edge structures, through systematic drilling experiments, a new type of solid cemented carbide drill was developed and the drill geometry was optimized. Results With the new type drill,the drilling force decreases by 10%-20%, the drilling productivity (drilled holes per hour) increases by 2-3 times, and the drilling precision and surface finish increase by one level. Conclusion The new type drill possesses excellent drilling performance.
基金supported by grants of the National Natural Science Foundation of China(30270202,39870103)Chinese Academy of Sciences(kscx2-yw-z-1021)
文摘We assessed habitat preference and population status of the Sichuan Jay (Perisoreus internigrans),a poorly known Chinese endemic bird,at two sites (Zhuoni and Jiuzhaigou) in the Qinghai-Tibetan plateau between 2001 and 2004.Mean group size was 3.8 jays.Each group occupied a mean home range of 42.0 ha during the breeding season,and the mean internest distance was 2.7 km.These data indicated that the jays used less than ten percent of the available habitats and occurred at an overall density of only 0.6 jays per km2.Radio-tracked Sichuan Jays had a strong preference for mature montane coniferous forests and avoided areas dominated by shrubs,while the utilization of young conifers,grassland,and human residential habitat types did not differ significantly from the values expected from the home-range availabilities of these habitats generally.
基金supported by the 863 Program of China(No.2013AA064201)National Science and Technology Major Project(No.2016ZX05003-003)
文摘Various migration methods have been proposed to image high-angle geological structures and media with strong lateral velocity variations; however, the problems of low precision and high computational cost remain unresolved. To describe the seismic wave propagation in media with lateral velocity variations and to image high-angle structures, we propose the generalized screen propagator based on particle swarm optimization (PSO-GSP), for the precise fitting of the single-square-root operator. We use the 2D SEG/EAGE salt model to test the proposed PSO-GSP migration method to image the faults beneath the salt dome and compare the results to those of the conventional high-order generalized screen propagator (GSP) migration and split-step Fourier (SSF) migration. Moreover, we use 2D marine data from the South China Sea to show that the PSO-GSP migration can better image strong reflectors than conventional imaging methods.
基金Supported by Major Project of Chinese National Programs for Fundamental Research and Development(2006CB400502)National Natural Science Funds for Distinguished Young Scholar(40625015)~~
文摘[Objective] The aim was to study the dynamic variation of extinction coefficient of corn population, so as to improve the accuracy of assessment on net primary productivity (NPP) or yield. [Method] Based on the data of photosynthetic active radiation and leaf area index during corn growing season (from May to September) in 2006, observed in Jinzhou observation station of corn farmland ecosystem, China Meteorological Administration, the dynamic variation of extinction coefficient of corn population was analyzed. [Result] There was a great daily variation in the extinction coefficient of corn population during growing season, and the maximum value appeared from 7:00 to 9:00 and from 15:00 to 17:00, while the minimum could be found around 12:00, but the amplitude of variation decreased in tasseling stage. On a large time scale (5 d), there was a parabolic relationship between extinction coefficient (K) and leaf area index (LAI), with determination coefficient R2 of 0.960 7. The simulation equation of extinction coefficient, based on the sun elevation angle or leaf area index, had poor accuracy at various time during growing season, so a new dynamic model of extinction coefficient was established, namely K=λ(0.784 8-0.001 6θ)(0.154 8LAI2-0.558 6LAI+0.654). [Conclusion] The effect of sun elevation angle and leaf area index on extinction coefficient during corn growing season was considered in the new dynamic model of extinction coefficient, and its simulated result was superior to that of single-factor model.
基金Supported by National Key Technology Research and Development Program of China(2011BAD16B11-02YJ01,2012BAD04B01-02)Key Science and Technology Program of Heilongjiang Province+2 种基金China(GA13B101)Heilongjiang Postdoctoral Sustentation Fund(LBH-Z10038)the Funds of Heilongjiang Academy of Agricultural Sciences for Distinguished Young Scholars(2014)~~
文摘[Objective] This study was conducted to construct a super-high yield population of Japnica rice in cold regions of North China and to explore its characteristics. [Method] The super rice variety Longjing 21 was selected as the experimental material. Different row spacing(two levels), plant spacing(three levels) and seedling number per hill(three levels) were designed in field trials. Then, the growth stages,dry matter accumulation, leaf area, yield and yield components of these different treatments were measured. [Result] Rice yield had significantly negative correlation with plant spacing and row spacing, but no significant correlation with seedling number per hill. Rice yield was mainly affected by plant spacing, and less affected by seedling number per hill. The best recommended specifications for plant spacing of super rice variety Longjing 21 were 24 cm for row spacing, 12 cm for plant spacing and five seedlings per hill, and the expected yield was 10 473.0 kg/hm^2.The increased number of total spikelets(4.5×108hm2or more) in populations was the major reason for high yield. Super-high yield populations had fewer tillers at the early growth stage and achieved the expected number of productive tillers at critical leaf-age(June 25), and tiller number peaked at jointing stage(July 6) and was about 1.2 times of the expected number. The percentage of productive tillers in total tillers of super-high yield population was more than 85% at heading stage. At middle growth stage(from jointing to heading stage), the dry matter accumulation, leaf area index(LAI) at heading stage, effective leaf area, spikelet number of population,spikelet number per leaf area unit(cm2), and culm-sheath weight per stem of super-high yield population were significantly higher than those of other populations.At late growth stage(from heading to maturity stage), the leaf area decreasing rate of super-high yield population was significantly smaller than that of other populations. At late growth stage(from heading to maturity stage), the leaf area decreasing rate, crop growth rate, net assimilation rate, biomass accumulation, number of filled grains per leaf area unit(cm^2) and grain weight per leaf area unit(cm^2) of high-yield population were significantly higher than those of other populations. Output and translocation of dry matter(weight per stem and sheath and total filling rate at maturity) from heading to milky stage of super-high yield population were significantly higher than those of other populations. [Conclusion] The characteristics of superhigh yield rice in cold region of North China are enriching the amount of actual filling of sink through improving photosynthetic efficiency from heading to maturity stage on the basis of enough panicle numbers.
基金Project(51978585)supported by the National Natural Science Foundation,ChinaProject(2022YFB2603404)supported by the National Key Research and Development Program,China+1 种基金Project(U1734207)supported by the High-speed Rail Joint Fund Key Projects of Basic Research,ChinaProject(2023NSFSC1975)supported by the Sichuan Nature and Science Foundation Innovation Research Group Project,China。
文摘The problems associated with vibrations of viaducts and low-frequency structural noise radiation caused by train excitation continue to increase in importance.A new floating-slab track vibration isolator-non-obstructive particle damping-phononic crystal vibration isolator is proposed herein,which uses the particle damping vibration absorption technology and bandgap vibration control theory.The vibration reduction performance of the NOPD-PCVI was analyzed from the perspective of vibration control.The paper explores the structure-borne noise reduction performance of the NOPD-PCVIs installed on different bridge structures under varying service conditions encountered in practical engineering applications.The load transferred to the bridge is obtained from a coupled train-FST-bridge analytical model considering the different structural parameters of bridges.The vibration responses are obtained using the finite element method,while the structural noise radiation is simulated using the frequency-domain boundary element method.Using the particle swarm optimization algorithm,the parameters of the NOPD-PCVI are optimized so that its frequency bandgap matches the dominant bridge structural noise frequency range.The noise reduction performance of the NOPD-PCVIs is compared to the steel-spring isolation under different service conditions.
文摘Co-infection with hepatitis C virus and humanimmunodeficiency virus is common in certainpopulations. Among HCV(+) persons, 10 % are alsoHIV (+), and among HIV (+) persons, 25 % are alsoHCV(+). Many studies have shown that in intravenousdrug users, co-infection prevalence can be as high as90-95 %. There is increasing evidence supporting theconcept that people infected with HIV have a muchmore rapid course of their hepatitis C infection.Treatment of co-infection is often challenging becausehighly active anti-retroviral therapy (HAART) therapyis frequently hepatotoxic, especially in the presence ofHCV. The purpose of this review is to describe theeffects that HIV has on hepatitis C, the effects thathepatitis C has on HIV, and the treatment options inthis challenging population.
文摘In this paper,the author study the spectrum of high rank differential operators T (n) (t) of C 0 Semigroup T(t) ,given an approach to construct the spectral set opetator T (n) (t) ,and discussed the relation between the spectral points of both T (n) (t) and infinitesimal generator A of T(t) .
基金国家杰出青年科学基金,the Research Fund for the Doctoral Program of Higher Education of China
文摘Recently, the Clarkson and Kruskal direct method has been modified to find new similarity reductions (conditional similarity reductions) of nonlinear systems and the results obtained by the modified direct method cannot be obtained by the current classical and/or non-classical Lie group approach. In this paper, we show that the conditional similarity reductions of the Jimbo-Miwa equation can be reobtained by adding an additional constraint equation to the original model to form a conditional equation system first and then solving the model system by means of the classical Lie group approach.
基金Supported by 11th 5-year Key Program for Science and Technology Development of China,No.2006BAI02A08
文摘AIM: To increase attendance tor colonoscopy among nonadherent high-risk individuals for colorectal cancer (CRC) screening in China. METHODS: During the first 12 mo without intervention, only 428 of the 2398 high-risk subjects attended a scheduled colonoscopy examination. The 1970 subjects who did not attend for CRC screening were enrolled in the present study. Prior barrier investigation was performed to ascertain the reasons for nonadherence. A barrier-focused intervention program was then established and implemented among eligible nonadherent subjects by telephone interviews and on-site consultations. The completion rates of colonoscopy during the first 12 mo without intervention and the second 12 mo with intervention were compared. Variations in the effect of the intervention on some high-risk factors and barrier characteristics were analyzed using logistic regression. RESULTS: 540 subjects who were not eligible were excluded from the study. The colonoscopy attendance rate was 23.04% (428/1858) during the first 12 mo without intervention, and 37.69% (539/1430) during the second 12 mo with intervention (P 〈 0.001). Logistic regression analysis showed that the intervention was more effective among subjects with only objective barriers (OR: 34.590, 95% CI: 23.204-51.563) or subjects with some specific highrisk characteristics: first-degree relatives diagnosed with CRC (OR: 1.778, 95% CI: 1.010-3.131), personal history of intestinal polyps (OR: 3.815, 95% CI: 1.994-7.300) and positive result for immunochemical fecal occult blood testing (OR: 2.718, 95% CI: 1.479-4.996). CONCLUSION: The barrier-focused telephone or on- site consultation intervention appears to be a feasible means to improve colonoscopy attendance among nonadherent high-risk subjects for CRC screening in China.
文摘A systematic approach was adopted to investigate the nutrient limiting factors in gray-brown purple soils and yellow soils derived from limestone in Chongqing, China, to study balanced fertilization for corn, sweet potato and wheat in rotation. The results showed that N, P and K were deficient in both soils, Cu, Mn, S andZn in the gray-brown purple soils and Ca, Mg, Mo and Zn for the yellow soils. Balanced fertilizer application increased yields of corn, sweet potato and wheat by 28.4%, 28.7% and 4.4%, respectively, as compared to the local farmers' practice. The systematic approach can be considered as one of the most efficient and reliable methods in fertility study.
文摘The effects of nitrogen, phosphorus and potassium application level, seed rate and transplanting density on the growth and development of rice plants were studied to find out nutrient status in high-yielding rice plants and to increase grain yield by adequate fertilization. There was an equilibrium relationship among nutrient elements for high-yielding rice plant populations. The equilibrium index of nutrient amount, content and distribution in high-yielding rice plants should be generally greater than-2 but less than 2. The optimum nutritive proportion of nitrogen: phosphorus: potassium assimilated by the plants was about 10: 2: 9 at the ripening stage. But the content and the proportion varied with the growth stages. Therefore, the nutrient in rice plant populations should be in a dynamic equilibrium, so as to achieve high yield.
文摘Pancreatic cancer is difficult to diagnose at an early stage and is associated with a very poor survival.Ten percent of pancreatic cancers result from genetic susceptibility and/or familial aggregation.Individuals from families with multiple affected first-degree relatives and those with a known cancer-causing genetic mutation have been shown to be at much higher risk of developing pancreatic cancer.Recent efforts have focused on detecting disease at an earlier stage to improve survival in these high-risk groups.This article reviews high-risk groups,screening methods,and current screening programs and their results.