Acute myocardial infarction(AMI)is a leading cause of death and disability worldwide and consists of two distinct cardiac pathologies:ST-elevation myocardial infarction(STEMI)and non-ST-elevation myocardial infarction...Acute myocardial infarction(AMI)is a leading cause of death and disability worldwide and consists of two distinct cardiac pathologies:ST-elevation myocardial infarction(STEMI)and non-ST-elevation myocardial infarction(NSTEMI).[1]In China,AMI is widely recognized as a predominant cause of mortality in both urban and rural demographics,based on the 2022 Report on Cardiovascular Health and Diseases in China;moreover,its mortality rate has been reported to be rising,with a recurrence rate of 2.5%within one year.展开更多
Background: Early research describing the concept of intensity-modulated conformal radiotherapy (IMRT) was based on 7 to 9 beams to reach an adequate level of modulation. Nevertheless, its implementation demands signi...Background: Early research describing the concept of intensity-modulated conformal radiotherapy (IMRT) was based on 7 to 9 beams to reach an adequate level of modulation. Nevertheless, its implementation demands significant resources. Our objective was to compare the compliance and homogeneity of target dose distribution between simplified IMRT and 3D-CRT in patients with cervical cancer and to assess the clinical value of simplified IMRT. Materials and Methods: From 2016 to 2017, 17 patients with stage IIB - IIIC cervical cancer were treated with external beam radiotherapy using simplified IMRT (12 cases) or 3DCRT (05 cases) and brachytherapy. Prior to radiotherapy, CT scans were conducted to delineate the target volume. The clinical target volume (CTV) included the uterus, primary tumor, supravaginal portion of the cervix, paracervical tissue, common iliac, internal and external iliac lymph nodes, obturator, and pre sacral lymph nodes, and the surrounding tissues. If the lower vagina was involved, the target volume included the whole vagina. The planning target volume (PTV) included the CTV with 1 cm anteriorly and 0.5 cm in all other directions. The PTV received 95% of 45 Gy (1.8 Gy/25 fraction). Dose-volume histogram, conformity index, homogeneity index, and treatment time per fraction were compared. Results: The 3D-CRT plan was more homogeneous than the simplified IMRT plan, while the simplified IMRT plan was more conformal. The volume of small bowels that received high-dose radiation significantly increased with simplified IMRT compared to 3D-CRT. Treatment time per fraction was 6 and 13 minutes for 3D-CRT and simplified IMRT, respectively. Conclusion: The simplified IMRT treatment plan is technically and dosimetrically acceptable and an alternative to the classic 3D-CRT plan for cervical cancer. It provides better dose distribution than 3D-CRT. However, the 3D-CRT treatment plan significantly reduced the overall treatment time per fraction.展开更多
Aiming at high cost and low efficiency of conventional branch bending method in the modern intensive planting and labor-saving cultivation mode of young pear trees,this paper provides a new branch bending method with ...Aiming at high cost and low efficiency of conventional branch bending method in the modern intensive planting and labor-saving cultivation mode of young pear trees,this paper provides a new branch bending method with wide source of raw materials,cheap price and simple operation,which is also suitable for the management of low-age branches in the process of high grafting and upgrading of traditional big trees.展开更多
This paper investigates the hydrodynamic characteristics of floating truncated cylinders undergoing horizontal and vertical motions due to earthquake excitations in the finite water depth.The governing equation of the...This paper investigates the hydrodynamic characteristics of floating truncated cylinders undergoing horizontal and vertical motions due to earthquake excitations in the finite water depth.The governing equation of the hydrodynamic pressure acting on the cylinder is derived based on the radiation theory with the inviscid and incompressible assumptions.The governing equation is solved by using the method of separating variables and analytical solutions are obtained by assigning reasonable boundary conditions.The analytical result is validated by a numerical model using the exact artificial boundary simulation of the infinite water.The main variation and distribution characteristics of the hydrodynamic pressure acting on the side and bottom of the cylinder are analyzed for different combinations of wide-height and immersion ratios.The added mass coefficient of the cylinder is calculated by integrating the hydrodynamic pressure and simplified formulas are proposed for engineering applications.The calculation results show that the simplified formulas are in good agreement with the analytical solutions.展开更多
Toppling failure of rock mass/soil slope is an important geological and environmental problem.Clarifying its failure mechanism under different conditions has great significance in engineering.The toppling failure of a...Toppling failure of rock mass/soil slope is an important geological and environmental problem.Clarifying its failure mechanism under different conditions has great significance in engineering.The toppling failure of a cutting slope occurred in a hydropower station in Kyushu,Japan illustrates that the joint characteristic played a significant role in the occurrence of rock slope tipping failure.Thus,in order to consider the mechanical properties of jointed rock mass and the influence of geometric conditions,a simplified analytical approach based on the limit equilibrium method for modeling the flexural toppling of cut rock slopes is proposed to consider the influence of the mechanical properties and geometry condition of jointed rock mass.The theoretical solution is compared with the numerical solution taking Kyushu Hydropower Station in Japan as one case,and it is found that the theoretical solution obtained by the simplified analysis method is consistent with the numerical analytical solution,thus verifying the accuracy of the simplified method.Meanwhile,the Goodman-Bray approach conventionally used in engineering practice is improved according to the analytical results.The results show that the allowable slope angle may be obtained by the improved Goodman-Bray approach considering the joint spacing,the joint frictional angle and the tensile strength of rock mass together.展开更多
Natural product elansolid A belongs to one type of polyketide macrolactone with promising antibiotic activity.Pre-viously,the first total synthesis of elansolid A in 28 longest linear sequence(LLS)and 41 steps in tota...Natural product elansolid A belongs to one type of polyketide macrolactone with promising antibiotic activity.Pre-viously,the first total synthesis of elansolid A in 28 longest linear sequence(LLS)and 41 steps in total has been achieved.Herein,the simplified analog of elansolid A,featured with a cyclohexyl-fused 19-memebered macrolactone,was proposed,and its asymmetric total synthesis based on a convergent strategy and key reactions exemplified by desymmetric alcoholysis of anhydride,Pd-catalyzed Stille coupling,Suzuki-Miyaura coupling as well as Mukaiyama macrolactonization was finished.展开更多
In order to compensate the dispersion accumulated in a single mode fiber(SMF)for higher communication capacity,a simplified dispersion-compensation microstructure fiber(DC-MSF)with seven cores is proposed in this pape...In order to compensate the dispersion accumulated in a single mode fiber(SMF)for higher communication capacity,a simplified dispersion-compensation microstructure fiber(DC-MSF)with seven cores is proposed in this paper.The fiber’s cladding is made of pure silica without air holes,and its outer cores are composed of six germanium up-doped cylinders,which has the advantage of simple structure.The finite element method(FEM)and beam propagation method(BPM)are used to study the properties of the fiber,and the relationship between the structural parameters of the fiber and the dispersion,as well as the phase matching wavelength,is obtained.By optimizing the structural parameters of the fiber,the dispersion of the fiber can reach-5291.47 ps·nm^(-1)·km^(-1) at 1550 nm,and the coupling loss to the conventional single-mode fiber is only 0.137 d B.Compared with the conventional dispersion-compensation fiber,the fiber has lots of advantages,such as single mode transmission,easy to fabricate and low coupling loss with traditional SMF,etc.展开更多
Composts are recognised as an important source of nutrients for crops. The study aims to valorise agricultural by-products by composts made from broiler (A), laying hen (B) and bovine (C) manures in soilless tomato cu...Composts are recognised as an important source of nutrients for crops. The study aims to valorise agricultural by-products by composts made from broiler (A), laying hen (B) and bovine (C) manures in soilless tomato cultivation. Treatments consisted of these three composts and controls consisting of coconut fibres fed with a nutrient solution. The system is a randomised Fisher block with three replications. Each elementary plot consisted of nine tomato plants. Chemical parameters of the substrates and agronomic parameters of the plants were recorded from 14 to 49 days after transplanting (DAT). The pH stabilised at around 6.2 after varying from 7.1 to 8.0 in the composts. The high electrical conductivity (5.9 - 6.01 dS/m) was less than 1 dS/m at 49 DAT. Agromorphological parameters were close to the controls. Fruit necrosis was higher in the compost-based substrates (13.75% - 32.22%) than in the controls (<2%). Healthy fruit yields from the composts (38.7 - 48.7 t/ha) were high, although lower than those from the controls (49.9 - 57.4 t/ha). Fruit harvested from these substrates had a longer average shelf life (38.23 days) than the controls (28.5 days). This study showed that composts have fertilising properties for soilless tomato cultivation, in particular that of laying hen manure (48.33 t/ha). These composts could provide an alternative to the use of chemical fertilisers in soilless tomato cultivation.展开更多
According to the design specifications,the construction of extended piles involves traversing the tunnel’s upper region and extending to the underlying rock layer.To address this challenge,a subterranean transfer str...According to the design specifications,the construction of extended piles involves traversing the tunnel’s upper region and extending to the underlying rock layer.To address this challenge,a subterranean transfer structure spanning multiple subway tunnels was proposed.Deliberating on the function of piles in the transfer structure as springs with axial and bending stiffness,and taking into account the force balance and deformation coordination conditions of beams and plates within the transfer structure,we established a simplified mechanical model that incorporates soil stratification by combining it with the Winkler elastic foundation beam model.The resolved established simplifiedmechanicalmodel employed finite difference technology and the Newton-Simpsonmethod,elucidating the mechanical mechanism of the transfer structure.The research findings suggest that the load carried by the upper structural columns can be transferred to the pile foundation beneath the beams through the transfer structure,subsequently reaching the deep soil layer and ensuring minimal impact on adjacent tunnels.The established simplified analysis method can be used for stress analysis of the transfer structure,concurrently considering soil stratification,pile foundation behavior,and plate action.The pile length,pile section size,and beam section size within the transfer structure should account for the characteristics of the upper load,ensuring an even distribution of the beam bending moment.展开更多
The authors constructed a simplified model of spring wheat (Triticum aestivum L.) carbon assimilation and dry matter accumulation (DMA) process which consisted of two independent variables, day length (L) and total...The authors constructed a simplified model of spring wheat (Triticum aestivum L.) carbon assimilation and dry matter accumulation (DMA) process which consisted of two independent variables, day length (L) and total daily radiation (TDR). Leaf water potential (Ψ) was incorporated into the simplified growth model based on the assumption that both light use efficiency (α) and CO 2 conductance of assimilation (g c) were depressed by water limitation. Finally,Ψ was estimated from a regression equation in which the independent variables were relative soil water content in the upper 80 cm (θ R,80 ), ambient temperature (T a), vapor pressure deficit (VPD), the cumulative leaf water potential below thresholds of -1.5 MPa (Ψ c,1.5 ). Some applications in research program of field experiment of atmosphere_land surface processes in Heihe River region were tested. The simulated data agreed well with the data observed at Linze oasis in 1989 for various levels of water supply and at Zhangye oasis in 1992 in the field. The analysis and simulation using the model demonstrated that the simplified growth model could describe very well the DMA process of spring wheat with and without water limitation in the region of HEIFE (Heihe field experiment).展开更多
According to the severe drop in the planting area of cotton in recent years, cotton variety Yinshan 8 was intercropped with onions and watermelon by using efficient and simplified interplanting cultivation techniques,...According to the severe drop in the planting area of cotton in recent years, cotton variety Yinshan 8 was intercropped with onions and watermelon by using efficient and simplified interplanting cultivation techniques, such as large-scale and intensive planting, mechanized intertillage, integrated management of water and fertilizer, etc. The application of the techniques could reduce production cost, improve the comprehensive benefit of cotton planting, increase farmers＇ income, and promote the sustainable development of rural economy.展开更多
[Objective] The aim was to select simplified high-yielding cultivation technology of rice. [Method] The research explored three methods of farmland prepara- tion, transplanting, and fertilization including shallow rot...[Objective] The aim was to select simplified high-yielding cultivation technology of rice. [Method] The research explored three methods of farmland prepara- tion, transplanting, and fertilization including shallow rotary tillage and deep ploughing, mechanical transplanting and hand transplanting, controlled-release fertilizer and quantitative fertilization in order to investigate effects of different treatment groups on rice characteristics, economic characteristics, as well as labor saving, yield increasing and profit improving. [Result] Rice increased by 596.4-809.55 kg/hm2, labor saving reached 120-135 per hm2, and profit improved in the range from 5 521.39 to 8 727.48 yuan/hm2 in the treatment groups by combinations of shallow rotary tillage, mechanical transplanting, and controlled-release fertilizer, of shallow rotary tillage, mechanical transplanting, and quantitative fertilization, and of deep ploughing, mechanical transplanting, and controlled release fertilizer. [Conclusion] The three models are of promising prospects in production.展开更多
In view of the problems of completely depending on rain, low and unstable yield and complicated planting of dry land foxtail millet, the light simplified cultivation techniques of wide row and double ridge with filmin...In view of the problems of completely depending on rain, low and unstable yield and complicated planting of dry land foxtail millet, the light simplified cultivation techniques of wide row and double ridge with filming, fertilizing and sowing on one for foxtail millet was formed through the integration of plastic film mulching technology and mechanized production technology by Institute of Millet crops of Hebei Academy of Agriculture and Forestry Sciences, and the techniques were introduced from the key technologies of pre-sowing preparation, sowing, supporting equipment, field management, harvesting, plastic film recycling.展开更多
In order to solve the problem that dry-land foxtail millet production completely relies on rainwater with the characteristics of low instable yield, manual thinning and weeding, high labor intensity, and labor and tim...In order to solve the problem that dry-land foxtail millet production completely relies on rainwater with the characteristics of low instable yield, manual thinning and weeding, high labor intensity, and labor and time saving, Millet Research Institute of Hebei Academy of Agriculture and Forestry Sciences integrated furrow sowing beside plastic film covering micro-ridges, simplified cultivation and mechanized production, forming the simplified foxtail millet cultivation technique adopting furrow sowing beside plastic film covering micro-ridges. This study introduced the technique points of the simplified foxtail millet cultivation technique adopting furrow sowing beside plastic film covering micro-ridges, including preparation before sowing,sowing, attached agricultural machines, field management, harvest and residual film recovery.展开更多
The prosperous post buckling load capacity of web plates of box girders can be used.In this article,the post buckling behaviour of web plates of box girders under different loading conditions is theoretically analyz...The prosperous post buckling load capacity of web plates of box girders can be used.In this article,the post buckling behaviour of web plates of box girders under different loading conditions is theoretically analyzed and on the basis of domestic and overseas design codes of steel structures,the corresponding simplified analysis methods are put forward for the engineering design or code revision.It is proved that the simplified methods are safe,efficient and practicable through the comparison between several results.展开更多
Scale effect of ISWs loads on Floating Production Storage and Offloading(FPSO) is studied in this paper. The application conditions of KdV, eKdV and MCC ISWs theories are used in the numerical method. The depthaverage...Scale effect of ISWs loads on Floating Production Storage and Offloading(FPSO) is studied in this paper. The application conditions of KdV, eKdV and MCC ISWs theories are used in the numerical method. The depthaveraged velocities induced by ISWs are used for the velocity-inlet boundary. Three scale ratio numerical models λ=1, 20 and 300 were selected, which the scale ratio is the size ratio of numerical models to the experimental model.The comparisons between the numerical and former experimental results are performed to verify the feasibility of numerical method. The comparisons between the numerical and simplified theoretical results are performed to discuss the applicability of the simplified theoretical model summarized from the load experiments. Firstly, the numerical results of λ=1 numerical model showed a good agreement with former experimental and simplified theoretical results. It is feasible to simulate the ISWs loads on FPSO by the numerical method. Secondly, the comparisons between the results of three scale ratio numerical models and experimental results indicated that the scale ratios have more significant influence on the experimental horizontal forces than the vertical forces. The scale effect of horizontal forces mainly results from the different viscosity effects associated with the model’s dimension.Finally, through the comparisons between the numerical and simplified theoretical results for three scale ratio models, the simplified theoretical model of the pressure difference and friction forces exerted by ISWs on FPSO is applied for large-scale or full-scale FPSO.展开更多
In recent years, precast segmental concrete bridge columns became prevalent because of the benefits of accelerated construction, low environmental impact, high quality and low life cycle costs. The lack of a detailed ...In recent years, precast segmental concrete bridge columns became prevalent because of the benefits of accelerated construction, low environmental impact, high quality and low life cycle costs. The lack of a detailed configuration and appropriate design procedure to ensure a comparable performance with monolithic construction has impeded this structural system from being widely used in areas of high seismicity. In this study, precast segmental bridge column cyclic loading tests were conducted to investigate the performance of unbonded post-tensioned segmental bridge columns. One monolithic and two precast segmental columns were tested. The preeast segmental column exhibited minor damage and small residual displacement after the maximum 7% cyclic drift; energy dissipation （ED） can be enhanced byadding ED bars. The experimental results were modeled by a simplified pushover method （SPOM）, as well as a fiber model （FIBM） finite element method. Forty-five cases of columns with different aspect ratios, axial load ratios and ED bar ratios were analyzed with the SPOM and FIBM, respectively. Using these parametric results, a simplified design method was suggested by regressive analysis. Satisfactory correlation was found between the experimental results and the simplified design method for preeast segmental columns with different design parameters.展开更多
A simple control structure in servo system is occasionally needed for simple industrial application which precise and high control performance is not exessively important so that the cost production can be reduced eff...A simple control structure in servo system is occasionally needed for simple industrial application which precise and high control performance is not exessively important so that the cost production can be reduced efficiently. Simplified vector control, which has simple control structure, is utilized as the permanent magnet synchronous motor control algorithm and genetic algorithm is used to tune three PI controllers used in simplified vector control. The control performance is obtained from simulation and investigated to verify the feasibility of the algorithm to be applied in the real application. Simulation results show that the speed and torque responses of the system in both continuous time and discrete time can achieve good performances. Furthermore, simplified vector control combined with genetic algorithm has a similar perfofmance with conventional field oriented control algorithm and possible to be realized into the real simple application in the future.展开更多
AIM To simplify the diagnostic criteria for superficial esophageal squamous cell carcinoma(SESCC) on Narrow Band Imaging combined with magnifying endoscopy(NBI-ME).METHODS This study was based on the post-hoc analysis...AIM To simplify the diagnostic criteria for superficial esophageal squamous cell carcinoma(SESCC) on Narrow Band Imaging combined with magnifying endoscopy(NBI-ME).METHODS This study was based on the post-hoc analysis of a randomized controlled trial. We performed NBI-ME for 147 patients with present or a history of squamous cell carcinoma in the head and neck, or esophagus between January 2009 and June 2011. Two expert endoscopistsdetected 89 lesions that were suspicious for SESCC lesions, which had been prospectively evaluated for the following 6 NBI-ME findings in real time: "intervascular background coloration"; "proliferation of intrapapillary capillary loops(IPCL)"; and "dilation", "tortuosity", "change in caliber", and "various shapes(VS)" of IPCLs(i.e., Inoue's tetrad criteria). The histologic examination of specimens was defined as the gold standard for diagnosis. A stepwise logistic regression analysis was used to identify candidates for the simplified criteria from among the 6 NBI-ME findings for diagnosing SESCCs. We evaluated diagnostic performance of the simplified criteria compared with that of Inoue's criteria.RESULTS Fifty-four lesions(65%) were histologically diagnosed as SESCCs and the others as low-grade intraepithelial neoplasia or inflammation. In the univariate analysis, proliferation, tortuosity, change in caliber, and VS were significantly associated with SESCC(P < 0.01). The combination of VS and proliferation was statistically extracted from the 6 NBI-ME findings by using the stepwise logistic regression model. We defined the combination of VS and proliferation as simplified dyad criteria for SESCC. The areas under the curve of the simplified dyad criteria and Inoue's tetrad criteria were 0.70 and 0.73, respectively. No significant difference was shown between them. The sensitivity, specificity, and accuracy of diagnosis for SESCC were 77.8%, 57.1%, 69.7% and 51.9%, 80.0%, 62.9% for the simplified dyad criteria and Inoue's tetrad criteria, respectively.CONCLUSION The combination of proliferation and VS may serve as simplified criteria for the diagnosis of SESCC using NBIME.展开更多
基金supported by the Natural Science Foundation of Shandong Province(ZR2021QH096,ZR2020MH024)the National Natural Science Foundation of China(82300354,882070345)+2 种基金the Academic Promotion Program of Shandong First Medical University(2019QL012)the Shandong Taishan Scholarship(to SHY)fund of Tianjin Zhongxin Pharmaceutical Group Co.,Ltd。
文摘Acute myocardial infarction(AMI)is a leading cause of death and disability worldwide and consists of two distinct cardiac pathologies:ST-elevation myocardial infarction(STEMI)and non-ST-elevation myocardial infarction(NSTEMI).[1]In China,AMI is widely recognized as a predominant cause of mortality in both urban and rural demographics,based on the 2022 Report on Cardiovascular Health and Diseases in China;moreover,its mortality rate has been reported to be rising,with a recurrence rate of 2.5%within one year.
文摘Background: Early research describing the concept of intensity-modulated conformal radiotherapy (IMRT) was based on 7 to 9 beams to reach an adequate level of modulation. Nevertheless, its implementation demands significant resources. Our objective was to compare the compliance and homogeneity of target dose distribution between simplified IMRT and 3D-CRT in patients with cervical cancer and to assess the clinical value of simplified IMRT. Materials and Methods: From 2016 to 2017, 17 patients with stage IIB - IIIC cervical cancer were treated with external beam radiotherapy using simplified IMRT (12 cases) or 3DCRT (05 cases) and brachytherapy. Prior to radiotherapy, CT scans were conducted to delineate the target volume. The clinical target volume (CTV) included the uterus, primary tumor, supravaginal portion of the cervix, paracervical tissue, common iliac, internal and external iliac lymph nodes, obturator, and pre sacral lymph nodes, and the surrounding tissues. If the lower vagina was involved, the target volume included the whole vagina. The planning target volume (PTV) included the CTV with 1 cm anteriorly and 0.5 cm in all other directions. The PTV received 95% of 45 Gy (1.8 Gy/25 fraction). Dose-volume histogram, conformity index, homogeneity index, and treatment time per fraction were compared. Results: The 3D-CRT plan was more homogeneous than the simplified IMRT plan, while the simplified IMRT plan was more conformal. The volume of small bowels that received high-dose radiation significantly increased with simplified IMRT compared to 3D-CRT. Treatment time per fraction was 6 and 13 minutes for 3D-CRT and simplified IMRT, respectively. Conclusion: The simplified IMRT treatment plan is technically and dosimetrically acceptable and an alternative to the classic 3D-CRT plan for cervical cancer. It provides better dose distribution than 3D-CRT. However, the 3D-CRT treatment plan significantly reduced the overall treatment time per fraction.
基金Technology Innovation Special Project of Hebei Academy of Agriculture and Forestry Sciences(2022KJCXZX-CGS-7,2023KJCXZX-CGS-11)Key Research and Development Program of Hebei Province(21326308D-1-2)+1 种基金Hebei Agriculture Research System(HBCT2024170406)China Agricultural(Pear)Research System(CARS-28-27).
文摘Aiming at high cost and low efficiency of conventional branch bending method in the modern intensive planting and labor-saving cultivation mode of young pear trees,this paper provides a new branch bending method with wide source of raw materials,cheap price and simple operation,which is also suitable for the management of low-age branches in the process of high grafting and upgrading of traditional big trees.
基金financially supported by the National Natural Science Foundation of China(Grant Nos.52078010 and 52101321)the National Key Research and Development Program of China(Grant No.2022YFC3004300).
文摘This paper investigates the hydrodynamic characteristics of floating truncated cylinders undergoing horizontal and vertical motions due to earthquake excitations in the finite water depth.The governing equation of the hydrodynamic pressure acting on the cylinder is derived based on the radiation theory with the inviscid and incompressible assumptions.The governing equation is solved by using the method of separating variables and analytical solutions are obtained by assigning reasonable boundary conditions.The analytical result is validated by a numerical model using the exact artificial boundary simulation of the infinite water.The main variation and distribution characteristics of the hydrodynamic pressure acting on the side and bottom of the cylinder are analyzed for different combinations of wide-height and immersion ratios.The added mass coefficient of the cylinder is calculated by integrating the hydrodynamic pressure and simplified formulas are proposed for engineering applications.The calculation results show that the simplified formulas are in good agreement with the analytical solutions.
基金Project(52109132)supported by the National Natural Science Foundation of ChinaProject(ZR2020QE270)supported by the Natural Science Foundation of Shandong Province,China+1 种基金Project(JMDPC202204)supported by State Key Laboratory of Strata Intelligent Control,Green Mining Co-founded by Shandong Province and the Ministry of Science and TechnologyShandong University of Science and Technology,China。
文摘Toppling failure of rock mass/soil slope is an important geological and environmental problem.Clarifying its failure mechanism under different conditions has great significance in engineering.The toppling failure of a cutting slope occurred in a hydropower station in Kyushu,Japan illustrates that the joint characteristic played a significant role in the occurrence of rock slope tipping failure.Thus,in order to consider the mechanical properties of jointed rock mass and the influence of geometric conditions,a simplified analytical approach based on the limit equilibrium method for modeling the flexural toppling of cut rock slopes is proposed to consider the influence of the mechanical properties and geometry condition of jointed rock mass.The theoretical solution is compared with the numerical solution taking Kyushu Hydropower Station in Japan as one case,and it is found that the theoretical solution obtained by the simplified analysis method is consistent with the numerical analytical solution,thus verifying the accuracy of the simplified method.Meanwhile,the Goodman-Bray approach conventionally used in engineering practice is improved according to the analytical results.The results show that the allowable slope angle may be obtained by the improved Goodman-Bray approach considering the joint spacing,the joint frictional angle and the tensile strength of rock mass together.
基金Project supported by the High-Level Talent Program of Yunnan Province(No.Y93D321261)the Regional Development Program for Young Scholars,Chinese Academy of Sciences(CAS)(No.E323521311)the Science and Technology Department of Yunan Province(Nos.202305AH34005,202401AS070096)。
文摘Natural product elansolid A belongs to one type of polyketide macrolactone with promising antibiotic activity.Pre-viously,the first total synthesis of elansolid A in 28 longest linear sequence(LLS)and 41 steps in total has been achieved.Herein,the simplified analog of elansolid A,featured with a cyclohexyl-fused 19-memebered macrolactone,was proposed,and its asymmetric total synthesis based on a convergent strategy and key reactions exemplified by desymmetric alcoholysis of anhydride,Pd-catalyzed Stille coupling,Suzuki-Miyaura coupling as well as Mukaiyama macrolactonization was finished.
基金supported by the Natural Science Foundation of Hebei Province(No.F2021203002)the Science and Technology Project of Hebei Education Department(No.ZD2021409)+2 种基金the Research Projects of Talent Project Training Funds of Hebei Province(No.C20221067)the Talent Project of Tangshan City(No.A202110009)the Science and Technology Project of Tangshan City(No.22130216G)。
文摘In order to compensate the dispersion accumulated in a single mode fiber(SMF)for higher communication capacity,a simplified dispersion-compensation microstructure fiber(DC-MSF)with seven cores is proposed in this paper.The fiber’s cladding is made of pure silica without air holes,and its outer cores are composed of six germanium up-doped cylinders,which has the advantage of simple structure.The finite element method(FEM)and beam propagation method(BPM)are used to study the properties of the fiber,and the relationship between the structural parameters of the fiber and the dispersion,as well as the phase matching wavelength,is obtained.By optimizing the structural parameters of the fiber,the dispersion of the fiber can reach-5291.47 ps·nm^(-1)·km^(-1) at 1550 nm,and the coupling loss to the conventional single-mode fiber is only 0.137 d B.Compared with the conventional dispersion-compensation fiber,the fiber has lots of advantages,such as single mode transmission,easy to fabricate and low coupling loss with traditional SMF,etc.
文摘Composts are recognised as an important source of nutrients for crops. The study aims to valorise agricultural by-products by composts made from broiler (A), laying hen (B) and bovine (C) manures in soilless tomato cultivation. Treatments consisted of these three composts and controls consisting of coconut fibres fed with a nutrient solution. The system is a randomised Fisher block with three replications. Each elementary plot consisted of nine tomato plants. Chemical parameters of the substrates and agronomic parameters of the plants were recorded from 14 to 49 days after transplanting (DAT). The pH stabilised at around 6.2 after varying from 7.1 to 8.0 in the composts. The high electrical conductivity (5.9 - 6.01 dS/m) was less than 1 dS/m at 49 DAT. Agromorphological parameters were close to the controls. Fruit necrosis was higher in the compost-based substrates (13.75% - 32.22%) than in the controls (<2%). Healthy fruit yields from the composts (38.7 - 48.7 t/ha) were high, although lower than those from the controls (49.9 - 57.4 t/ha). Fruit harvested from these substrates had a longer average shelf life (38.23 days) than the controls (28.5 days). This study showed that composts have fertilising properties for soilless tomato cultivation, in particular that of laying hen manure (48.33 t/ha). These composts could provide an alternative to the use of chemical fertilisers in soilless tomato cultivation.
基金supported by the Construction and Scientific Research Project of the Zhejiang Provincial Department of Housing and Urban-Rural Development(No.2021K126,Granted byM.J.,Long,URL:https://jst.zj.gov.cn/)the ScientificResearch Project of ChinaConstruction 4th Engineering Bureau(No.CSCEC4B-2022-KTA-10,Granted by Z.C.,Bai,URL:https://4 bur.cscec.com/)+2 种基金the Scientific Research Project of China Construction 4th Engineering Bureau(No.CSCEC4B-2023-KTA-10,Granted by D.J.,Geng,URL:https://4bur.cscec.com/)the Natural Science Foundation of Hubei Province(No.2022CFD055,Granted by N.,Dai,URL:https://kjt.hubei.gov.cn/)the National Key Research and Development Program of China under Grant No.2022YFC3803002.
文摘According to the design specifications,the construction of extended piles involves traversing the tunnel’s upper region and extending to the underlying rock layer.To address this challenge,a subterranean transfer structure spanning multiple subway tunnels was proposed.Deliberating on the function of piles in the transfer structure as springs with axial and bending stiffness,and taking into account the force balance and deformation coordination conditions of beams and plates within the transfer structure,we established a simplified mechanical model that incorporates soil stratification by combining it with the Winkler elastic foundation beam model.The resolved established simplifiedmechanicalmodel employed finite difference technology and the Newton-Simpsonmethod,elucidating the mechanical mechanism of the transfer structure.The research findings suggest that the load carried by the upper structural columns can be transferred to the pile foundation beneath the beams through the transfer structure,subsequently reaching the deep soil layer and ensuring minimal impact on adjacent tunnels.The established simplified analysis method can be used for stress analysis of the transfer structure,concurrently considering soil stratification,pile foundation behavior,and plate action.The pile length,pile section size,and beam section size within the transfer structure should account for the characteristics of the upper load,ensuring an even distribution of the beam bending moment.
文摘The authors constructed a simplified model of spring wheat (Triticum aestivum L.) carbon assimilation and dry matter accumulation (DMA) process which consisted of two independent variables, day length (L) and total daily radiation (TDR). Leaf water potential (Ψ) was incorporated into the simplified growth model based on the assumption that both light use efficiency (α) and CO 2 conductance of assimilation (g c) were depressed by water limitation. Finally,Ψ was estimated from a regression equation in which the independent variables were relative soil water content in the upper 80 cm (θ R,80 ), ambient temperature (T a), vapor pressure deficit (VPD), the cumulative leaf water potential below thresholds of -1.5 MPa (Ψ c,1.5 ). Some applications in research program of field experiment of atmosphere_land surface processes in Heihe River region were tested. The simulated data agreed well with the data observed at Linze oasis in 1989 for various levels of water supply and at Zhangye oasis in 1992 in the field. The analysis and simulation using the model demonstrated that the simplified growth model could describe very well the DMA process of spring wheat with and without water limitation in the region of HEIFE (Heihe field experiment).
文摘According to the severe drop in the planting area of cotton in recent years, cotton variety Yinshan 8 was intercropped with onions and watermelon by using efficient and simplified interplanting cultivation techniques, such as large-scale and intensive planting, mechanized intertillage, integrated management of water and fertilizer, etc. The application of the techniques could reduce production cost, improve the comprehensive benefit of cotton planting, increase farmers＇ income, and promote the sustainable development of rural economy.
文摘[Objective] The aim was to select simplified high-yielding cultivation technology of rice. [Method] The research explored three methods of farmland prepara- tion, transplanting, and fertilization including shallow rotary tillage and deep ploughing, mechanical transplanting and hand transplanting, controlled-release fertilizer and quantitative fertilization in order to investigate effects of different treatment groups on rice characteristics, economic characteristics, as well as labor saving, yield increasing and profit improving. [Result] Rice increased by 596.4-809.55 kg/hm2, labor saving reached 120-135 per hm2, and profit improved in the range from 5 521.39 to 8 727.48 yuan/hm2 in the treatment groups by combinations of shallow rotary tillage, mechanical transplanting, and controlled-release fertilizer, of shallow rotary tillage, mechanical transplanting, and quantitative fertilization, and of deep ploughing, mechanical transplanting, and controlled release fertilizer. [Conclusion] The three models are of promising prospects in production.
基金Supported by the National Key Technology R&D Program(2014BAD07B01-02)the Science and Technology Demonstration Project of Bohai Granary in Hebei Provincethe Special Fund for Agro-scientific Research in Public Interest(201303133-1-6)~~
文摘In view of the problems of completely depending on rain, low and unstable yield and complicated planting of dry land foxtail millet, the light simplified cultivation techniques of wide row and double ridge with filming, fertilizing and sowing on one for foxtail millet was formed through the integration of plastic film mulching technology and mechanized production technology by Institute of Millet crops of Hebei Academy of Agriculture and Forestry Sciences, and the techniques were introduced from the key technologies of pre-sowing preparation, sowing, supporting equipment, field management, harvesting, plastic film recycling.
基金Supported by the National Key Technology Research and Development Program(2014BAD07B01-02)Science and Technology Demonstration Project of Bohai Granary in Hebei ProvinceSpecial Fund of Agro-scientific Research in Public Interest(201303133-1-6)~~
文摘In order to solve the problem that dry-land foxtail millet production completely relies on rainwater with the characteristics of low instable yield, manual thinning and weeding, high labor intensity, and labor and time saving, Millet Research Institute of Hebei Academy of Agriculture and Forestry Sciences integrated furrow sowing beside plastic film covering micro-ridges, simplified cultivation and mechanized production, forming the simplified foxtail millet cultivation technique adopting furrow sowing beside plastic film covering micro-ridges. This study introduced the technique points of the simplified foxtail millet cultivation technique adopting furrow sowing beside plastic film covering micro-ridges, including preparation before sowing,sowing, attached agricultural machines, field management, harvest and residual film recovery.
基金Supported by Ministry of Metallurgical Industry of China
文摘The prosperous post buckling load capacity of web plates of box girders can be used.In this article,the post buckling behaviour of web plates of box girders under different loading conditions is theoretically analyzed and on the basis of domestic and overseas design codes of steel structures,the corresponding simplified analysis methods are put forward for the engineering design or code revision.It is proved that the simplified methods are safe,efficient and practicable through the comparison between several results.
基金financially supported by the National Natural Science Foundation of China(Grant No.11372184)the National Basic Research Program of China(973 Program,Grant Nos.2015CB251203-3 and 2013CB036103)
文摘Scale effect of ISWs loads on Floating Production Storage and Offloading(FPSO) is studied in this paper. The application conditions of KdV, eKdV and MCC ISWs theories are used in the numerical method. The depthaveraged velocities induced by ISWs are used for the velocity-inlet boundary. Three scale ratio numerical models λ=1, 20 and 300 were selected, which the scale ratio is the size ratio of numerical models to the experimental model.The comparisons between the numerical and former experimental results are performed to verify the feasibility of numerical method. The comparisons between the numerical and simplified theoretical results are performed to discuss the applicability of the simplified theoretical model summarized from the load experiments. Firstly, the numerical results of λ=1 numerical model showed a good agreement with former experimental and simplified theoretical results. It is feasible to simulate the ISWs loads on FPSO by the numerical method. Secondly, the comparisons between the results of three scale ratio numerical models and experimental results indicated that the scale ratios have more significant influence on the experimental horizontal forces than the vertical forces. The scale effect of horizontal forces mainly results from the different viscosity effects associated with the model’s dimension.Finally, through the comparisons between the numerical and simplified theoretical results for three scale ratio models, the simplified theoretical model of the pressure difference and friction forces exerted by ISWs on FPSO is applied for large-scale or full-scale FPSO.
基金National Natural Science Foundation of China under Grants Nos.51208268 and 51178429K.C.Wong Magna Fund in Ningbo University+1 种基金Transportation Science and Technology Project of Ningbo City under Grant No.201507Natural Science Foundation of Ningbo City under Grant No.2015A610293
文摘In recent years, precast segmental concrete bridge columns became prevalent because of the benefits of accelerated construction, low environmental impact, high quality and low life cycle costs. The lack of a detailed configuration and appropriate design procedure to ensure a comparable performance with monolithic construction has impeded this structural system from being widely used in areas of high seismicity. In this study, precast segmental bridge column cyclic loading tests were conducted to investigate the performance of unbonded post-tensioned segmental bridge columns. One monolithic and two precast segmental columns were tested. The preeast segmental column exhibited minor damage and small residual displacement after the maximum 7% cyclic drift; energy dissipation （ED） can be enhanced byadding ED bars. The experimental results were modeled by a simplified pushover method （SPOM）, as well as a fiber model （FIBM） finite element method. Forty-five cases of columns with different aspect ratios, axial load ratios and ED bar ratios were analyzed with the SPOM and FIBM, respectively. Using these parametric results, a simplified design method was suggested by regressive analysis. Satisfactory correlation was found between the experimental results and the simplified design method for preeast segmental columns with different design parameters.
文摘A simple control structure in servo system is occasionally needed for simple industrial application which precise and high control performance is not exessively important so that the cost production can be reduced efficiently. Simplified vector control, which has simple control structure, is utilized as the permanent magnet synchronous motor control algorithm and genetic algorithm is used to tune three PI controllers used in simplified vector control. The control performance is obtained from simulation and investigated to verify the feasibility of the algorithm to be applied in the real application. Simulation results show that the speed and torque responses of the system in both continuous time and discrete time can achieve good performances. Furthermore, simplified vector control combined with genetic algorithm has a similar perfofmance with conventional field oriented control algorithm and possible to be realized into the real simple application in the future.
文摘AIM To simplify the diagnostic criteria for superficial esophageal squamous cell carcinoma(SESCC) on Narrow Band Imaging combined with magnifying endoscopy(NBI-ME).METHODS This study was based on the post-hoc analysis of a randomized controlled trial. We performed NBI-ME for 147 patients with present or a history of squamous cell carcinoma in the head and neck, or esophagus between January 2009 and June 2011. Two expert endoscopistsdetected 89 lesions that were suspicious for SESCC lesions, which had been prospectively evaluated for the following 6 NBI-ME findings in real time: "intervascular background coloration"; "proliferation of intrapapillary capillary loops(IPCL)"; and "dilation", "tortuosity", "change in caliber", and "various shapes(VS)" of IPCLs(i.e., Inoue's tetrad criteria). The histologic examination of specimens was defined as the gold standard for diagnosis. A stepwise logistic regression analysis was used to identify candidates for the simplified criteria from among the 6 NBI-ME findings for diagnosing SESCCs. We evaluated diagnostic performance of the simplified criteria compared with that of Inoue's criteria.RESULTS Fifty-four lesions(65%) were histologically diagnosed as SESCCs and the others as low-grade intraepithelial neoplasia or inflammation. In the univariate analysis, proliferation, tortuosity, change in caliber, and VS were significantly associated with SESCC(P < 0.01). The combination of VS and proliferation was statistically extracted from the 6 NBI-ME findings by using the stepwise logistic regression model. We defined the combination of VS and proliferation as simplified dyad criteria for SESCC. The areas under the curve of the simplified dyad criteria and Inoue's tetrad criteria were 0.70 and 0.73, respectively. No significant difference was shown between them. The sensitivity, specificity, and accuracy of diagnosis for SESCC were 77.8%, 57.1%, 69.7% and 51.9%, 80.0%, 62.9% for the simplified dyad criteria and Inoue's tetrad criteria, respectively.CONCLUSION The combination of proliferation and VS may serve as simplified criteria for the diagnosis of SESCC using NBIME.
