Objective To observe the value of artificial intelligence(AI)models based on non-contrast chest CT for measuring bone mineral density(BMD).Methods Totally 380 subjects who underwent both non-contrast chest CT and quan...Objective To observe the value of artificial intelligence(AI)models based on non-contrast chest CT for measuring bone mineral density(BMD).Methods Totally 380 subjects who underwent both non-contrast chest CT and quantitative CT(QCT)BMD examination were retrospectively enrolled and divided into training set(n=304)and test set(n=76)at a ratio of 8∶2.The mean BMD of L1—L3 vertebrae were measured based on QCT.Spongy bones of T5—T10 vertebrae were segmented as ROI,radiomics(Rad)features were extracted,and machine learning(ML),Rad and deep learning(DL)models were constructed for classification of osteoporosis(OP)and evaluating BMD,respectively.Receiver operating characteristic curves were drawn,and area under the curves(AUC)were calculated to evaluate the efficacy of each model for classification of OP.Bland-Altman analysis and Pearson correlation analysis were performed to explore the consistency and correlation of each model with QCT for measuring BMD.Results Among ML and Rad models,ML Bagging-OP and Rad Bagging-OP had the best performances for classification of OP.In test set,AUC of ML Bagging-OP,Rad Bagging-OP and DL OP for classification of OP was 0.943,0.944 and 0.947,respectively,with no significant difference(all P>0.05).BMD obtained with all the above models had good consistency with those measured with QCT(most of the differences were within the range of Ax-G±1.96 s),which were highly positively correlated(r=0.910—0.974,all P<0.001).Conclusion AI models based on non-contrast chest CT had high efficacy for classification of OP,and good consistency of BMD measurements were found between AI models and QCT.展开更多
The gas_well system permanently installed in the soil was adopted for studying the dynamic relationship between CO 2 profiles and seedling root growth of Pinus sylvestris var. sylvestriformis (Takenouchi) Che...The gas_well system permanently installed in the soil was adopted for studying the dynamic relationship between CO 2 profiles and seedling root growth of Pinus sylvestris var. sylvestriformis (Takenouchi) Cheng et C. D. Chu. The study was conducted in the Open Research Station of Changbai Mountain Forest Ecological System, The Chinese Academy of Sciences from 1999 to 2001. Four treatments were arranged in the rectangular open_top chambers (OTCs): ambient CO 2+no_seedling, 700 μmol/mol CO 2+no_seedling, ambient CO 2 +seedlings, 700 μmol/mol CO 2+seedlings. By collecting and analyzing soil gas synchronously, it was found that the dynamics of CO 2 profiles were related to the biological activity of seedlings. There were more roots distributed in the top soil and the boundary layer across soil and sand, which made more contributions to the CO 2 profiles due to respiration root. Compared with the ambient CO 2, elevated CO 2 led to the peak of CO 2 concentration distribution shifted from soil surface layer to the boundary layer as seasonally growing of seedling roots. It is suggested the gas_well system is an inexpensive, non_destructive and relatively sensitive method for study of soil CO 2 concentration profiles.展开更多
[Objective] This study was aimed to review the controlling experience of pine wilt disease in the past 25 years, explore the theories and methods of controlling pine wilt disease, and improve the scientific level of c...[Objective] This study was aimed to review the controlling experience of pine wilt disease in the past 25 years, explore the theories and methods of controlling pine wilt disease, and improve the scientific level of controlling techniques and the protection capacity of healthy pine trees. [Method] Eleven items of effects were used to refine the theory of clearing dead pine trees affected by pine wilt disease, namely, ＂1 priority＂, ＂2 objections＂, ＂3 principles＂, ＂4 measures＂, and ＂5 manage- ments＂. On the basis of comprehensive control and complete removal of the infect- ed pine trees, a variety of comprehensive and efficient controlling methods were developed to carry out targeted chemical ecology trapping, bionic pesticide killing and releasing natural enemies of Sclerodermus guani, Dastarcus helophoroides. High ef- ficient emamectin benzoate immune injection was developed to inject the healthy pine trees for prevention, so as to extinguish the pine wilt disease. [Result] The pine wilt disease dropped from the peak of 3.5 million dead trees with an infecting area of 28 273 hectares in 1999 to 0.068 million with an area of 4 333 hectares in 2012 gradually, reducing by 98.06% in number and 84.84% in area, respectively. On the basis of removal, Dastarcus helophoroides was also released, which could make the number of dead pines decrease more significantly than the control, and af- ter releasing for 5 consecutive years, the dead pine trees dropped to 0.511 plant/hm2 in 2012, with a mortality rate of 0.022 7%, which achieved the control effect, reaching extremely significant level. ＂Forest land removal＋infected trees isolation＋natural enemy release＂ could extinguish the pine wilt disease. The test of isolating 24 heaps of infected pine trees showed that there were 9 heaps of pine trees extinguished the pine wilt disease, which controlled the occurrence of pine wilt disease for 100%, accounting for 37.5% of the total, in which the number of those isolated using iron netting and nylon net were 4 for each, accounting for 88.9%, and there was one heap using polypropylene net, accounting for 11.1%. The invention of em- amectin benzoate immune injection laid the foundation for extinguishing pine wilt disease. The follow checking of the effects of emamectin benzoate immune injection on pine wilt disease found that the number of dead trees caused by pine wilt dis- ease decreased significantly after injecting, and became very small in October of the next year, and the disease was completely extinguished in the third year. [Conclusionl Pine wilt disease could be controlled and extinguished with positive control by using ＂comprehensive cleaning＋industrialized removal＂, ＂comprehensive cleaning＋ natural enemy release＂, ＂comprehensive cleaning＋infected trees isolation＋natural ene- my release＂ and ＂comprehensive cleaning＋emamectin benzoate immune＂.展开更多
Meshfree method offers high accuracy and computational capability and constructs the shape function without relying on predefined elements. We comparatively analyze the global weak form meshfree methods, such as eleme...Meshfree method offers high accuracy and computational capability and constructs the shape function without relying on predefined elements. We comparatively analyze the global weak form meshfree methods, such as element-free Galerkin method （EFGM）, the point interpolation method （PIM）, and the radial point interpolation method （RPIM）. Taking two dimensional Poisson equation as an example, we discuss the support-domain dimensionless size, the field nodes, and background element settings with respect to their effect on calculation accuracy of the meshfree method. RPIM and EFGM are applied to controlled- source two-dimensional electromagnetic modeling with fixed shape parameters. The accuracy of boundary conditions imposed directly and by a penalty function are discussed in the case of forward modeling of two-dimensional magnetotellurics in a homogeneous medium model. The coupling algorithm of EFG-PIM and EFG-RPIM are generated by integrating the PIM or RPIM and EFGM. The results of the numerical modeling suggest the following. First, the proposed meshfree method and corresponding coupled methods are well-suited for electromagnetic numerical modeling. The accuracy of the algorithm is the highest when the support-domain dimensionless size is 1.0 and the distribution of field nodes is consistent with the nodes of background elements. Second, the accuracy of PIM and RPIM are lower than that of EFGM for the Poisson equation but higher than EFGM for the homogeneous medium MT response. Third, RPIM overcomes the matrix inversion problem of PIM and has a wider selection of support-domain dimensionless sizes as compared to RPIM.展开更多
Bursaphelenchus rainulfi isolated from dead pine trees in Zbejiang, China, is described and illustrated. It also provided some molecular characters of the Chinese population, including the PCR-RFLP and sequences of IT...Bursaphelenchus rainulfi isolated from dead pine trees in Zbejiang, China, is described and illustrated. It also provided some molecular characters of the Chinese population, including the PCR-RFLP and sequences of ITS region and D2-D3 expansion region of the large subunit （LSU） rRNA gene. Both the morphological characters and ITS-RFLP patterns match with the original description. The phylogenetic trees based on the 13 sequences of D2-D3 expansion region of the LSU rRNA gene and ITS region of Bursaphelenchus species were constructed, respectively, with the results showing the similar clades. The phylogenetic relationship based on the molecular data is similar to that with morphological characters. This is the first report of the species on pine wood in eastern China.展开更多
Thermally activated pinecone(TAP) was used for the adsorption of dimethyl trisulfide(DMTS)from aqueous solutions,which was proved to be the main odorous in algae-caused black bloom.The effects of adsorbent dosage,adso...Thermally activated pinecone(TAP) was used for the adsorption of dimethyl trisulfide(DMTS)from aqueous solutions,which was proved to be the main odorous in algae-caused black bloom.The effects of adsorbent dosage,adsorbate concentration and contact time on DMTS biosorption were studied.The TAP produced at 600℃ exhibited a relatively high surface area(519.69 m^2/g) and excellent adsorption capacity.The results show that the adsorption of DMTS was initially fast and that the equilibrium time was6 h.Higher initial DMTS concentrations led to lower removal percentages but higher adsorption capacity.The removal percentage of DMTS increased and the adsorption capacity of TAP decreased with an increase in adsorbent dosage.The adsorption process conforms well to a pseudo-second-order kinetics model.The adsorption of DMTS is more appropriately described by the Freundlich isotherm(R^2=0.996 1) than by the Langmuir isotherm(R^2=0.916 9).The results demonstrate that TAP could be an attractive low-cost adsorbent for removing DMTS from water.展开更多
Slack-Decode Simultaneously and Redundantly Threaded （SD-SRT） is proposed for detecting transient faults in processors. SD-SRT boosts the previously proposed SRT performance via definitely eliminating redundant inst...Slack-Decode Simultaneously and Redundantly Threaded （SD-SRT） is proposed for detecting transient faults in processors. SD-SRT boosts the previously proposed SRT performance via definitely eliminating redundant instructiou fetches. First, the fetch stage is moved out of the Spheres of Replication （SoR）, and a unified instruction-fetch-queue （IFQ） is exploited by both the leading and trailing threads. Second, a scheme called slack-decode cooperates with the unified IFQ to harmonize proceeding of the two threads. The simulations show that SD-SRT outperforms original SRT in terms of IPC by 15%, and decreases I-cache access by 42%. Meanwhile, SD-SRT leads to a lessened size and complexity for hardware structures such as load-value-queue and store-buffer.展开更多
文摘Objective To observe the value of artificial intelligence(AI)models based on non-contrast chest CT for measuring bone mineral density(BMD).Methods Totally 380 subjects who underwent both non-contrast chest CT and quantitative CT(QCT)BMD examination were retrospectively enrolled and divided into training set(n=304)and test set(n=76)at a ratio of 8∶2.The mean BMD of L1—L3 vertebrae were measured based on QCT.Spongy bones of T5—T10 vertebrae were segmented as ROI,radiomics(Rad)features were extracted,and machine learning(ML),Rad and deep learning(DL)models were constructed for classification of osteoporosis(OP)and evaluating BMD,respectively.Receiver operating characteristic curves were drawn,and area under the curves(AUC)were calculated to evaluate the efficacy of each model for classification of OP.Bland-Altman analysis and Pearson correlation analysis were performed to explore the consistency and correlation of each model with QCT for measuring BMD.Results Among ML and Rad models,ML Bagging-OP and Rad Bagging-OP had the best performances for classification of OP.In test set,AUC of ML Bagging-OP,Rad Bagging-OP and DL OP for classification of OP was 0.943,0.944 and 0.947,respectively,with no significant difference(all P>0.05).BMD obtained with all the above models had good consistency with those measured with QCT(most of the differences were within the range of Ax-G±1.96 s),which were highly positively correlated(r=0.910—0.974,all P<0.001).Conclusion AI models based on non-contrast chest CT had high efficacy for classification of OP,and good consistency of BMD measurements were found between AI models and QCT.
文摘The gas_well system permanently installed in the soil was adopted for studying the dynamic relationship between CO 2 profiles and seedling root growth of Pinus sylvestris var. sylvestriformis (Takenouchi) Cheng et C. D. Chu. The study was conducted in the Open Research Station of Changbai Mountain Forest Ecological System, The Chinese Academy of Sciences from 1999 to 2001. Four treatments were arranged in the rectangular open_top chambers (OTCs): ambient CO 2+no_seedling, 700 μmol/mol CO 2+no_seedling, ambient CO 2 +seedlings, 700 μmol/mol CO 2+seedlings. By collecting and analyzing soil gas synchronously, it was found that the dynamics of CO 2 profiles were related to the biological activity of seedlings. There were more roots distributed in the top soil and the boundary layer across soil and sand, which made more contributions to the CO 2 profiles due to respiration root. Compared with the ambient CO 2, elevated CO 2 led to the peak of CO 2 concentration distribution shifted from soil surface layer to the boundary layer as seasonally growing of seedling roots. It is suggested the gas_well system is an inexpensive, non_destructive and relatively sensitive method for study of soil CO 2 concentration profiles.
基金Supported by the Scientific Research Project of National Level of YANG Zhongqi of Chinese Academy of Forestry(2012AA101503)~~
文摘[Objective] This study was aimed to review the controlling experience of pine wilt disease in the past 25 years, explore the theories and methods of controlling pine wilt disease, and improve the scientific level of controlling techniques and the protection capacity of healthy pine trees. [Method] Eleven items of effects were used to refine the theory of clearing dead pine trees affected by pine wilt disease, namely, ＂1 priority＂, ＂2 objections＂, ＂3 principles＂, ＂4 measures＂, and ＂5 manage- ments＂. On the basis of comprehensive control and complete removal of the infect- ed pine trees, a variety of comprehensive and efficient controlling methods were developed to carry out targeted chemical ecology trapping, bionic pesticide killing and releasing natural enemies of Sclerodermus guani, Dastarcus helophoroides. High ef- ficient emamectin benzoate immune injection was developed to inject the healthy pine trees for prevention, so as to extinguish the pine wilt disease. [Result] The pine wilt disease dropped from the peak of 3.5 million dead trees with an infecting area of 28 273 hectares in 1999 to 0.068 million with an area of 4 333 hectares in 2012 gradually, reducing by 98.06% in number and 84.84% in area, respectively. On the basis of removal, Dastarcus helophoroides was also released, which could make the number of dead pines decrease more significantly than the control, and af- ter releasing for 5 consecutive years, the dead pine trees dropped to 0.511 plant/hm2 in 2012, with a mortality rate of 0.022 7%, which achieved the control effect, reaching extremely significant level. ＂Forest land removal＋infected trees isolation＋natural enemy release＂ could extinguish the pine wilt disease. The test of isolating 24 heaps of infected pine trees showed that there were 9 heaps of pine trees extinguished the pine wilt disease, which controlled the occurrence of pine wilt disease for 100%, accounting for 37.5% of the total, in which the number of those isolated using iron netting and nylon net were 4 for each, accounting for 88.9%, and there was one heap using polypropylene net, accounting for 11.1%. The invention of em- amectin benzoate immune injection laid the foundation for extinguishing pine wilt disease. The follow checking of the effects of emamectin benzoate immune injection on pine wilt disease found that the number of dead trees caused by pine wilt dis- ease decreased significantly after injecting, and became very small in October of the next year, and the disease was completely extinguished in the third year. [Conclusionl Pine wilt disease could be controlled and extinguished with positive control by using ＂comprehensive cleaning＋industrialized removal＂, ＂comprehensive cleaning＋ natural enemy release＂, ＂comprehensive cleaning＋infected trees isolation＋natural ene- my release＂ and ＂comprehensive cleaning＋emamectin benzoate immune＂.
基金supported by the National Nature Science Foundation of China(Grant No.40874055)the Natural Science Foundation of the Hunan Province,China(Grant No.14JJ2012)
文摘Meshfree method offers high accuracy and computational capability and constructs the shape function without relying on predefined elements. We comparatively analyze the global weak form meshfree methods, such as element-free Galerkin method （EFGM）, the point interpolation method （PIM）, and the radial point interpolation method （RPIM）. Taking two dimensional Poisson equation as an example, we discuss the support-domain dimensionless size, the field nodes, and background element settings with respect to their effect on calculation accuracy of the meshfree method. RPIM and EFGM are applied to controlled- source two-dimensional electromagnetic modeling with fixed shape parameters. The accuracy of boundary conditions imposed directly and by a penalty function are discussed in the case of forward modeling of two-dimensional magnetotellurics in a homogeneous medium model. The coupling algorithm of EFG-PIM and EFG-RPIM are generated by integrating the PIM or RPIM and EFGM. The results of the numerical modeling suggest the following. First, the proposed meshfree method and corresponding coupled methods are well-suited for electromagnetic numerical modeling. The accuracy of the algorithm is the highest when the support-domain dimensionless size is 1.0 and the distribution of field nodes is consistent with the nodes of background elements. Second, the accuracy of PIM and RPIM are lower than that of EFGM for the Poisson equation but higher than EFGM for the homogeneous medium MT response. Third, RPIM overcomes the matrix inversion problem of PIM and has a wider selection of support-domain dimensionless sizes as compared to RPIM.
基金Project (No.2002C34003) supported by the Science and Technology Department of Zhejiang Province,China
文摘Bursaphelenchus rainulfi isolated from dead pine trees in Zbejiang, China, is described and illustrated. It also provided some molecular characters of the Chinese population, including the PCR-RFLP and sequences of ITS region and D2-D3 expansion region of the large subunit （LSU） rRNA gene. Both the morphological characters and ITS-RFLP patterns match with the original description. The phylogenetic trees based on the 13 sequences of D2-D3 expansion region of the LSU rRNA gene and ITS region of Bursaphelenchus species were constructed, respectively, with the results showing the similar clades. The phylogenetic relationship based on the molecular data is similar to that with morphological characters. This is the first report of the species on pine wood in eastern China.
基金Supported by the Taihu Special Project of Water Pollution Control,Jiangsu Province(No.TH2013214)the National Water Pollution Control and Management Technology Major Project(No.2012ZX07103-005)+1 种基金the Industry-Academia Cooperation Innovation Fund Project of Jiangsu Province(No.BY2011165)the Open Foundation of State Key Laboratory of Lake Science and Environment,CAS(No.2014SKL005)
文摘Thermally activated pinecone(TAP) was used for the adsorption of dimethyl trisulfide(DMTS)from aqueous solutions,which was proved to be the main odorous in algae-caused black bloom.The effects of adsorbent dosage,adsorbate concentration and contact time on DMTS biosorption were studied.The TAP produced at 600℃ exhibited a relatively high surface area(519.69 m^2/g) and excellent adsorption capacity.The results show that the adsorption of DMTS was initially fast and that the equilibrium time was6 h.Higher initial DMTS concentrations led to lower removal percentages but higher adsorption capacity.The removal percentage of DMTS increased and the adsorption capacity of TAP decreased with an increase in adsorbent dosage.The adsorption process conforms well to a pseudo-second-order kinetics model.The adsorption of DMTS is more appropriately described by the Freundlich isotherm(R^2=0.996 1) than by the Langmuir isotherm(R^2=0.916 9).The results demonstrate that TAP could be an attractive low-cost adsorbent for removing DMTS from water.
文摘Slack-Decode Simultaneously and Redundantly Threaded （SD-SRT） is proposed for detecting transient faults in processors. SD-SRT boosts the previously proposed SRT performance via definitely eliminating redundant instructiou fetches. First, the fetch stage is moved out of the Spheres of Replication （SoR）, and a unified instruction-fetch-queue （IFQ） is exploited by both the leading and trailing threads. Second, a scheme called slack-decode cooperates with the unified IFQ to harmonize proceeding of the two threads. The simulations show that SD-SRT outperforms original SRT in terms of IPC by 15%, and decreases I-cache access by 42%. Meanwhile, SD-SRT leads to a lessened size and complexity for hardware structures such as load-value-queue and store-buffer.
