[Objective]The aim was to study on the characteristics of soil organic carbon and nitrogen in rubber (Hevea brasiliensis Muell-Arg) plantations at different age stages in the western region of Hainan Island,so as to...[Objective]The aim was to study on the characteristics of soil organic carbon and nitrogen in rubber (Hevea brasiliensis Muell-Arg) plantations at different age stages in the western region of Hainan Island,so as to evaluate the ecological benefits of rubber plantations and provide basic data for studying the effect of tropical land utilization/cover change on the global carbon and nitrogen cycle. [Method]The situs was in Danzhou city,western region of Hainan Island,and the samples were four kinds of rubber plantations soil at different ages and one kind of control check (pepper,Piper nigrum L.) soil. In this research,four quadrats were set up in each sample,and the size of each was 20 cm×20 cm. Four specimens were gathered from four layers of 0-15,15-30,30-45,45-60,and the average of them was the last analysis result of each sample. Soil density was measured by cutting ring method,soil containing and hygroscopic water was detected by oven drying method,soil organic carbon (SOC) was measured by low temperature heated outside potassium dichromate oxidation-colorimetry method,and soil total nitrogen (STN) was detected by semimicro Kjeldahl method. [Result]SOC contents of different layers in rubber plantations soil at different age stages (including the CK pepper soil,the same as below) varied little,and the content of SOC in surface layer (0-15 cm) was higher,while the underlayer (45-60 cm) was lower than the average value; there was significant difference in SOC content among different kinds of soil,and the content was of 6.03-7.78 g/kg,tapping young trees (7 years) CK pepper mature age trees (30 years) prophase of young trees (2 years) tapping trees (16 years); there was no significant difference in SOC storage among different kinds of soil,and the storage was of 61.33-74.29 t/hm2,mature age trees (30 years) tapping young trees (7 years) prophase of young trees (2 years) CK pepper tapping trees (16 years); there was significant difference in STN content among rubber plantations soil at different age stages,the content was of 410.86-664.14 mg/kg2,CK pepper tapping young trees (7 years) prophase of young trees (2 years) mature age trees (30 years) tapping trees (16 years),and STN content of tapping trees (16 years) soil was extremely lowest; there was significant difference in C/N ratio among different kinds of soil,the ratio was of 10.94-14.47,and the ratio of tapping trees (16 years) mature age trees (30 years) tapping young trees (7 years) CK pepper prophase of young trees (2 years). [Conclusion]There wasn't unhealthy effect of rubber trees planted in tropical area on the content and storage of SOC,the content of STN and the ratio of C/N. there was no significant difference between rubber plantations and CK pepper soil,and the effects of rubber plantation on soil carbon-nitrogen was similar to that of other tropical crops (such as pepper).展开更多
There are many factors in the occurrence of diabetes,which can result in insufficient insulin secretion and insulin receptor resistance.Including pituitary tumors,can also lead to the occurrence of diabetes,if the pri...There are many factors in the occurrence of diabetes,which can result in insufficient insulin secretion and insulin receptor resistance.Including pituitary tumors,can also lead to the occurrence of diabetes,if the primary disease can not be well controlled in time,such secondary diabetes control is more difficult.In the process of clinical diagnosis and treatment,these factors need to be taken into account,timely detection and treatment of primary diseases,so as to reduce the possibility of clinical missed diagnosis.展开更多
Examining age-specific heterogeneity of susceptibility to cardiovascular disease is also essential in individuals without prediabetes to determine its relative size and direction compared to those with prediabetes.Of ...Examining age-specific heterogeneity of susceptibility to cardiovascular disease is also essential in individuals without prediabetes to determine its relative size and direction compared to those with prediabetes.Of particular interest,age-specific heterogeneity in genetic susceptibility may exhibit opposite directions depending on the presence or absence of prediabetes.展开更多
The shear strength deterioration of bedding planes between different rock types induced by cyclic loading is vital to reasonably evaluate the stability of soft and hard interbedded bedding rock slopes under earthquake...The shear strength deterioration of bedding planes between different rock types induced by cyclic loading is vital to reasonably evaluate the stability of soft and hard interbedded bedding rock slopes under earthquake;however,rare work has been devoted to this subject due to lack of attention.In this study,experimental investigations on shear strength weakening of discontinuities with different joint wall material(DDJM)under cyclic loading were conducted by taking the interface between siltstone and mudstone in the Shaba slope of Yunnan Province,China as research objects.A total of 99 pairs of similar material samples of DDJM(81 pairs)and discontinuities with identical joint wall material(DIJM)(18 pairs)were fabricated by inserting plates,engraved with typical surface morphology obtained by performing three-dimensional laser scanning on natural DDJMs sampled from field,into mold boxes.Cyclic shear tests were conducted on these samples to study their shear strength changes with the cyclic number considering the effects of normal stress,joint surface morphology,shear displacement amplitude and shear rate.The results indicate that the shear stress vs.shear displacement curves under each shear cycle and the peak shear strength vs.cyclic number curves of the studied DDJMs are between those of DIJMs with siltstone and mudstone,while closer to those of DIJMs with mudstone.The peak shear strengths of DDJMs exhibit an initial rapid decline followed by a gradual decrease with the cyclic number and the decrease rate varies from 6%to 55.9%for samples with varied surface morphology under different testing conditions.The normal stress,joint surface morphology,shear displacement amplitude and shear rate collectively influence the shear strength deterioration of DDJM under cyclic shear loading,with the degree of influence being greater for larger normal stress,rougher surface morphology,larger shear displacement amplitude and faster shear rate.展开更多
To understand the engine main bearings' working condition is important in order to improve the performance of engine. However, thermal effects and thermal effect deformations of engine main bearings are rarely consid...To understand the engine main bearings' working condition is important in order to improve the performance of engine. However, thermal effects and thermal effect deformations of engine main bearings are rarely considered simultaneously in most studies. A typical finite element model is selected and the effect of thermoelastohydrodynamic(TEHD) reaction on engine main bearings is investigated. The calculated method of main bearing's thermal hydrodynamic reaction and journal misalignment effect is finite difference method, and its deformation reaction is calculated by using finite element method. The oil film pressure is solved numerically with Reynolds boundary conditions when various bearing characteristics are calculated. The whole model considers a temperature-pressure-viscosity relationship for the lubricant, surface roughness effect, and also an angular misalignment between the journal and the bearing. Numerical simulations of operation of a typical I6 diesel engine main bearing is conducted and importance of several contributing factors in mixed lubrication is discussed. The performance characteristics of journal misaligned main bearings under elastohydrodynamic(EHD) and TEHD loads of an I6 diesel engine are received, and then the journal center orbit movement, minimum oil film thickness and maximum oil film pressure of main bearings are estimated over a wide range of engine operation. The model is verified through the comparison with other present models. The TEHD performance of engine main bearings with various effects under the influences of journal misalignment is revealed, this is helpful to understand EHD and TEHD effect of misaligned engine main bearings.展开更多
The deep-water area of the northern South China Sea, which has active and complicated tectonics, is rich in natural gas and gas hydrate. While the tectonic characteristics is different obviously between the east and t...The deep-water area of the northern South China Sea, which has active and complicated tectonics, is rich in natural gas and gas hydrate. While the tectonic characteristics is different obviously between the east and the west because of the special tectonic position and tectonic evolution process. In terms of submarine geomorphology, the eastern shelf-slope structure in Pearl River Mouth Basin is characterized by having wide sub-basins and narrow intervening highs, whereas the western (Qiongdongnan Basin) structure is characterized by narrow sub- basins and wide uplift. As to the structural features, the deep-water sags in the east are all structurally half- grabens, controlled by a series of south-dipping normal faults. While the west sags are mainly characterised by graben structures with faulting in both the south and north. With regards to the tectonic evolution, the east began neotectonic activity when the post-rifting stage had completed at the end of the Middle Miocene. In the Baiyun Sag, tectonic activity became strong and was characterised by rapid subsidence and obvious faulting. Whereas in the west, neotectonic activity began at the end of the Late Miocene with rapid deposition and weak fault activity.展开更多
China bears a large burden of global maternal mortality, and the largest burden of maternal deaths in China is in poor western provinces. This study aimed to investigate the trends in maternal mortality and its associ...China bears a large burden of global maternal mortality, and the largest burden of maternal deaths in China is in poor western provinces. This study aimed to investigate the trends in maternal mortality and its associated factors in Guizhou province of western China between 1996 and 2009, and examine differences between minority and non-minority counties. A population-based, longitudinal, retrospective study was performed in a poor western province of China with a considerably large ethnic minority population. All 86 counties/districts of Guizhou were included with population at county, township and village level. Maternal mortality data were collected from routine reporting database of Guizhou Provincial Health Bureau. Trend and comparative analyses and multivariate linear regression analyses were performed using SPSS 17.0. Maternal mortality ratio(MMR) and its change over time, differences between ethnic groups were analyzed. A declining trend in maternal mortality and rising trend in hospital delivery in Guizhou was observed; ethnic differences between two ethnic groups persisted. The reduction in maternal mortality between 1996 and 2009 was related with increased gross domestic product, decreased male illiteracy rate, and increased hospital delivery rate. We found the declining trends in maternal mortality in Guizhou with persisting ethnic differences. The declining trends are related with economic development, hospital delivery and male illiteracy. Effective health education on maternal health is urgently needed for the minority groups, and basic education for the new generation should be enhanced to eradicate the illiteracy.展开更多
This paper describes systematic measurement of fiber migration and distribution pattern of twist at different radial positions of rotor spun yarn mixed tracer fiber by Hi-Scope Video Microscope System. The positions o...This paper describes systematic measurement of fiber migration and distribution pattern of twist at different radial positions of rotor spun yarn mixed tracer fiber by Hi-Scope Video Microscope System. The positions of tracer fibers were measured in three dimensions accurately, and the migration index and the twist distribution at different radial positions of rotor yarn were calculated and analyzed. This research result serves to provide useful references for further study on the structural mechanics of rotor spun yarn.展开更多
Carbon Nano-Tube Field Effect Transistors(CNTFETs) are being widely studied as possible successors to silicon MOSFETs.Using current mode has many advantages such as performing sum operation by means of a simple wired ...Carbon Nano-Tube Field Effect Transistors(CNTFETs) are being widely studied as possible successors to silicon MOSFETs.Using current mode has many advantages such as performing sum operation by means of a simple wired connection.Also,direction of the current can be used to exhibit the sign of digits.It is expected that the advantages of current mode approaches will become even more important with increased speed requirements and decreased supply voltage.In this paper,we present five new circuit designs for differential absolute value in current mode logic which have been simulated by CNTFET model.The considered base current for this model is 2 μA and supply voltage is 0.9 V.In all of our designs we used N-type CNTFET current mirrors which operate as truncated difference circuits.The operation of Differential Absolute Value circuit calculates the difference between two input currents and our circuit designs are operate in 8 logic levels.展开更多
Characteristic finite difference fractional step schemes are put forward. The electric potential equation is described by a seven-point finite difference scheme, and the electron and hole concentration equations are t...Characteristic finite difference fractional step schemes are put forward. The electric potential equation is described by a seven-point finite difference scheme, and the electron and hole concentration equations are treated by a kind of characteristic finite difference fractional step methods. The temperature equation is described by a fractional step method. Thick and thin grids are made use of to form a complete set. Piecewise threefold quadratic interpolation, symmetrical extension, calculus of variations, commutativity of operator product, decomposition of high order difference operators and prior estimates are also made use of. Optimal order estimates in l2 norm are derived to determine the error of the approximate solution. The well-known problem is thorongley and completely solred.展开更多
It is still a great challenge to effectively optimize the electronic structure of photocatalysts for the sustainable and efficient conversion of solar energy to H2 energy.To resolve this issue,we report on the optimiz...It is still a great challenge to effectively optimize the electronic structure of photocatalysts for the sustainable and efficient conversion of solar energy to H2 energy.To resolve this issue,we report on the optimization of the electronic structure of hollow-concave carbon nitride(C3N4)by deviating the sp2-hybridized structure of its tri-s-triazine component from the two-dimensional plane.The embedded CuInS2 into C3N4(CuInS2@C3N4)demonstrates an increased light-capturing capability and the promoted directional transfer of the charge carrier.Research results reveal that the hollow structure with an apparent potential difference between the concave and convex C3N4 drives the directional transfer of the photoinduced electrons from the Cu 2p orbital of CuInS2 to the N 1s orbital of C3N4 with the S-scheme principle.The H2 evolution efficiency over CuInS2@C3N4 is up to 373μmol?h^-1 g^-1 under visible irradiation,which is 1.57 and 1.35 times higher than those over the bulk g-C3N4 with 1 wt%Pt(238μmol?h^-1 g^-1)and g-C3N4 with 3 wt%Pd(276μmol?h^-1 g^-1),respectively.This suggests that the apparent potential difference of the hollow C3N4 results in an efficient reaction between the photogenerated electrons and H2O.This work supplies a new strategy for enhancing the sustainable solar conversion performance of carbon nitride,which can also be suitable for other semiconductors.展开更多
Objective Prenatal phthalate exposure has been associated with placental inflammatory factors and infant allergic rhinitis(AR).However,the results are inconclusive.We designed a population-based cohort study to examin...Objective Prenatal phthalate exposure has been associated with placental inflammatory factors and infant allergic rhinitis(AR).However,the results are inconclusive.We designed a population-based cohort study to examine the effects of placental inflammatory biomarkers on the sex-dependent associations between maternal phthalate exposure and infant AR.Methods A total of 2,348 pregnant women from Ma’anshan,Anhui Province,China,who were screened before antenatal visits and met the inclusion criteria,were included in the present study.We assessed AR in their offspring aged 36 months with a questionnaire.Quantitative PCR was performed to measure placental inflammatory factor m RNAs.The independent samples t-test and multivariable logistic regression were used to determine the associations between infant AR and maternal phthalates.Results Childhood AR may be related to education and family monthly income(P = 0.01).The phthalate metabolites,mono(2-ethylhexyl) phthalate(MEHP),mono(2-ethyl-5-hydroxyl) phthalate(MEHHP),in pregnant women were associated with a significantly increased risk for infant AR in males[P < 0.05;odds ratio(OR):1.285;95% confidence interval(CI):1.037-1.591,and OR:1.232,95% CI:1.008-1.507,respectively],but not females.Additionally,irritably-increased expression levels of HO-1 and IL-4 were associated with AR in male infants(OR:1.175;95% CI:1.038-1.329 and OR:1.181;95% CI:1.056-1.322,respectively).The association between maternal urinary MEHHP and placental HO-1 was marginally significant according to mediation analysis.Conclusion The associations of maternal MEHHP and MEOHP levels with fetal AR in males were significant.Placental HO-1 was a fractional mediator in the associations between MEHHP and AR.Thus,the placenta should be further investigated as a potential mediator of maternal exposure-induced disease risk in children.展开更多
A modified alternating direction implicit algorithm is proposed to solve the full-vectorial finite-difference beam propagation method formulation based on H fields. The cross-coupling terms are neglected in the first ...A modified alternating direction implicit algorithm is proposed to solve the full-vectorial finite-difference beam propagation method formulation based on H fields. The cross-coupling terms are neglected in the first sub-step, but evaluated and doubly used in the second sub-step. The order of two sub-steps is reversed for each transverse magnetic field component so that the cross-coupling terms are always expressed in implicit form, thus the calculation is very efficient and stable. Moreover, an improved six-point finite-difference scheme with high accuracy independent of specific structures of waveguide is also constructed to approximate the cross-coupling terms along the transverse directions. The imaginary-distance procedure is used to assess the validity and utility of the present method. The field patterns and the normalized propagation constants of the fundamental mode for a buried rectangular waveguide and a rib waveguide are presented. Solutions are in excellent agreement with the benchmark results from the modal transverse resonance method.展开更多
The minimal clinically important difference(MCID)represents a pivotal metric in bridging the gap between statistical significance and clinical relevance,addressing the direct impact of medical interventions from the p...The minimal clinically important difference(MCID)represents a pivotal metric in bridging the gap between statistical significance and clinical relevance,addressing the direct impact of medical interventions from the patient's perspective.This comprehensive review analyzes the evolution,applications,and challenges of MCID across medical specialties,emphasizing its necessity in ensuring that clinical outcomes not only demonstrate statistical significance but also offer genuine clinical utility that aligns with patient expectations and needs.We discuss the evolution of MCID since its inception in the 1980s,its current applications across various medical specialties,and the methodologies used in its calculation,highlighting both anchor-based and distribution-based approaches.Furthermore,the paper delves into the challenges associated with the application of MCID,such as methodological variability and the interpretation difficulties that arise in clinical settings.Recommendations for the future include standardizing MCID calculation methods,enhancing patient involvement in setting MCID thresholds,and extending research to incorporate diverse global perspectives.These steps are critical to refining the role of MCID in patient-centered healthcare,addressing existing gaps in methodology and interpretation,and ensuring that medical interventions lead to significant,patient-perceived improvements.展开更多
To clarify the determinant factors and inter-group differences of Chinese urban residents' edible vegetable oil consuming behavior is very important for us to understand their consumption features of edible vegeta...To clarify the determinant factors and inter-group differences of Chinese urban residents' edible vegetable oil consuming behavior is very important for us to understand their consumption features of edible vegetable oil,so as to guide their consuming behavior and improve China's vegetable oil industry security.In this article,urban residents of China's three traditional vegetable oil main production areas have been chosen as study objects,and multiple linear regression and one-way ANOVA have been used to do empirical analysis on the determinant factors and inter-group differences of their edible vegetable oil consuming behavior.The results indicate that the edible vegetable oil consuming behavior of urban residents from China's three traditional vegetable oil main production areas show a trend of diversification;" publicity measures"," preference evaluation"," personal characteristics" and " family characteristics" remarkably affect urban residents' edible vegetable oil consuming behavior and show obvious provincial characteristics.In addition,urban residents from different groups show differences in terms of " publicity measures" and " preference evaluation".展开更多
The coordinated development between touristization and urbanization is the key to optimizing regional industrial structure and building a long-term dynamic mechanism for urbanization. Based on constructing the measure...The coordinated development between touristization and urbanization is the key to optimizing regional industrial structure and building a long-term dynamic mechanism for urbanization. Based on constructing the measurement index system of touristization and urbanization level, the evaluation model on the coupled and coordinated degree is used in this paper to measure the inter-provincial pattern of the coupled and coordinated relationship between touristization and urbanization in 31 provinces and autonomous regions in China. The results show that the coupled and coordinated relationship between touristization and urbanization is significantly different in different regions, which presents a gradient decline pattern of the highest in the east, the lower in the middle and the lowest in the west. In the future, measures should be taken to promote the coordinated development between touristization and urbanization in accordance with the regional differences and actual development needs.展开更多
Ecosystem Services(ES)are common-pool resources that can be valued by people’s willingness to pay(WTP).In contrast to place-based WTP research at the community-level,the stakeholders tend to be geographically diverse...Ecosystem Services(ES)are common-pool resources that can be valued by people’s willingness to pay(WTP).In contrast to place-based WTP research at the community-level,the stakeholders tend to be geographically diverse,and the benefits are not spatially apparent on the national level.Aiming to find the geographical diversity of the WTP for ES at the large scale,this study implemented an online survey of more than 25,000 samples to detect the WTP of Chinese people for water conservation,soil retention,carbon fixation,pollution decomposition,biodiversity conservation,and aesthetic existence of the Tibetan Plateau.The results showed the top limit of payments was 1,080.95 CNY/year/capita on average,and people would like to pay 172.40 CNY/year/capita for water conservation,which is the highest among the six ES.The percent of people“Aged 16–35”,“Government agency staff”and“Know WTP”influenced payments at provincial level.On an individual level,people’s knowledge and attitudes directly drove the payment amounts,as well as their ecosystem management decisions.Consequently,geographical diversity of the payment for ES exists in China,and in contrast to the objective social structure and spatial accessibility of ES,people’s knowledge and attitudes were the main driving forces of this geographical diversity.These findings suggest that a bottom-up adaptive governance approach is encouraged for managing common pool resources in developing countries.展开更多
Objective To explore the differences in three different registration methods of cone beam computed tomography(CBCT)-guided down-regulated intense radiation therapy for lung cancer as well as the effects of tumor locat...Objective To explore the differences in three different registration methods of cone beam computed tomography(CBCT)-guided down-regulated intense radiation therapy for lung cancer as well as the effects of tumor location,treatment mode,and tumor size on registration.Methods This retrospective analysis included 80 lung cancer patients undergoing radiotherapy in our hospital from November 2017 to October 2019 and compared automatic bone registration,automatic grayscale(t+r)registration,and automatic grayscale(t)positioning error on the X-,Y-,and Z-axes under three types of registration methods.The patients were also grouped according to tumor position,treatment mode,and tumor size to compare positioning errors.Results On the X-,Y-,and Z-axes,automatic grayscale(t+r)and automatic grayscale(t)registration showed a better trend.Analysis of the different treatment modes showed differences in the three registration methods;however,these were not statistically significant.Analysis according to tumor sizes showed significant differences between the three registration methods(P<0.05).Analysis according to tumor positions showed differences in the X-and Y-axes that were not significant(P>0.05),while the autopsy registration in the Z-axis showed the largest difference in the mediastinal and hilar lymph nodes(P<0.05).Conclusion The treatment mode was not the main factor affecting registration error in lung cancer.Three registration methods are available for tumors in the upper and lower lungs measuring<3 cm;among these,automatic gray registration is recommended,while any gray registration method is recommended for tumors located in the mediastinal hilar site measuring<3 cm and in the upper and lower lungs≥3 cm.展开更多
An idea on interfacial equilibrium-potential differences () which are generated for the extraction of univalent metal picrate (MPic) and divalent ones (MPic2) by crown ethers (L) into high-polar diluents was improved....An idea on interfacial equilibrium-potential differences () which are generated for the extraction of univalent metal picrate (MPic) and divalent ones (MPic2) by crown ethers (L) into high-polar diluents was improved. These potentials were clarified with some experimental extraction-data reported before on the M = Ag(I), Ca(II), Sr(II) and Ba(II) extraction with 18-crown-6 ether (18C6) and benzo-18C6 into 1,2-dichloroethane (DCE) and nitrobenzene (NB). Consequently, it was demonstrated that the? values from the extraction-experimentally obtained logKD,Pic ones are in agreement with or close to those calculated from charge balance equations in many cases, where the symbol, KD,Pic, denotes an individual distribution constant of Pic﹣ into the DCE or NB phase. Also, it was experimentally shown that extraction constants based on the overall extraction equilibria do not virtually contain the? terms in their functional expressions.展开更多
Both Jane Austen and Eileen Chang are popular female writers.However they endowed their heroines with differentfates:Elizabeth in Pride and Prejudice earns a happily-ever-after with her Mr.Right,while Gu Manlu in Eigh...Both Jane Austen and Eileen Chang are popular female writers.However they endowed their heroines with differentfates:Elizabeth in Pride and Prejudice earns a happily-ever-after with her Mr.Right,while Gu Manlu in Eighteen Springs has toembrace death long before her time.They are destined due to their different family backgrounds and different characters which aredepicted in the novels.展开更多
基金Supported by the Project of the Basic Research Operation Cost of State Level Research Institutes "Long-term Location Investigation of Basic Data for Rubber Production " ( XJSYWFZX-2008-14 and XJSYWFZX-2007-2)the Project Natural Sciences Fund of Hainan Province (807045)~~
文摘[Objective]The aim was to study on the characteristics of soil organic carbon and nitrogen in rubber (Hevea brasiliensis Muell-Arg) plantations at different age stages in the western region of Hainan Island,so as to evaluate the ecological benefits of rubber plantations and provide basic data for studying the effect of tropical land utilization/cover change on the global carbon and nitrogen cycle. [Method]The situs was in Danzhou city,western region of Hainan Island,and the samples were four kinds of rubber plantations soil at different ages and one kind of control check (pepper,Piper nigrum L.) soil. In this research,four quadrats were set up in each sample,and the size of each was 20 cm×20 cm. Four specimens were gathered from four layers of 0-15,15-30,30-45,45-60,and the average of them was the last analysis result of each sample. Soil density was measured by cutting ring method,soil containing and hygroscopic water was detected by oven drying method,soil organic carbon (SOC) was measured by low temperature heated outside potassium dichromate oxidation-colorimetry method,and soil total nitrogen (STN) was detected by semimicro Kjeldahl method. [Result]SOC contents of different layers in rubber plantations soil at different age stages (including the CK pepper soil,the same as below) varied little,and the content of SOC in surface layer (0-15 cm) was higher,while the underlayer (45-60 cm) was lower than the average value; there was significant difference in SOC content among different kinds of soil,and the content was of 6.03-7.78 g/kg,tapping young trees (7 years) CK pepper mature age trees (30 years) prophase of young trees (2 years) tapping trees (16 years); there was no significant difference in SOC storage among different kinds of soil,and the storage was of 61.33-74.29 t/hm2,mature age trees (30 years) tapping young trees (7 years) prophase of young trees (2 years) CK pepper tapping trees (16 years); there was significant difference in STN content among rubber plantations soil at different age stages,the content was of 410.86-664.14 mg/kg2,CK pepper tapping young trees (7 years) prophase of young trees (2 years) mature age trees (30 years) tapping trees (16 years),and STN content of tapping trees (16 years) soil was extremely lowest; there was significant difference in C/N ratio among different kinds of soil,the ratio was of 10.94-14.47,and the ratio of tapping trees (16 years) mature age trees (30 years) tapping young trees (7 years) CK pepper prophase of young trees (2 years). [Conclusion]There wasn't unhealthy effect of rubber trees planted in tropical area on the content and storage of SOC,the content of STN and the ratio of C/N. there was no significant difference between rubber plantations and CK pepper soil,and the effects of rubber plantation on soil carbon-nitrogen was similar to that of other tropical crops (such as pepper).
基金Supported by Traditional Chinese medicine science and technology project in Jiangsu province,No.YB2015113the Science and Technology Program of Nantong Health Committee,No.MA2019003,and No.MA2019003+1 种基金Science and Technology Program of Nantong City,No.Key003,and No.JCZ2022040Kangda College of Nanjing Medical University,No.KD2022KYJJZD019,No.KD2021JYYJYB025,and No.KD2022KYJJZD022。
文摘There are many factors in the occurrence of diabetes,which can result in insufficient insulin secretion and insulin receptor resistance.Including pituitary tumors,can also lead to the occurrence of diabetes,if the primary disease can not be well controlled in time,such secondary diabetes control is more difficult.In the process of clinical diagnosis and treatment,these factors need to be taken into account,timely detection and treatment of primary diseases,so as to reduce the possibility of clinical missed diagnosis.
基金Supported by National Research Foundation of Korea,No.2018R1A2B6004867.
文摘Examining age-specific heterogeneity of susceptibility to cardiovascular disease is also essential in individuals without prediabetes to determine its relative size and direction compared to those with prediabetes.Of particular interest,age-specific heterogeneity in genetic susceptibility may exhibit opposite directions depending on the presence or absence of prediabetes.
基金supported by the National Natural Science Foundation of China(Grant Nos.42377182,52079133 and 41931295).
文摘The shear strength deterioration of bedding planes between different rock types induced by cyclic loading is vital to reasonably evaluate the stability of soft and hard interbedded bedding rock slopes under earthquake;however,rare work has been devoted to this subject due to lack of attention.In this study,experimental investigations on shear strength weakening of discontinuities with different joint wall material(DDJM)under cyclic loading were conducted by taking the interface between siltstone and mudstone in the Shaba slope of Yunnan Province,China as research objects.A total of 99 pairs of similar material samples of DDJM(81 pairs)and discontinuities with identical joint wall material(DIJM)(18 pairs)were fabricated by inserting plates,engraved with typical surface morphology obtained by performing three-dimensional laser scanning on natural DDJMs sampled from field,into mold boxes.Cyclic shear tests were conducted on these samples to study their shear strength changes with the cyclic number considering the effects of normal stress,joint surface morphology,shear displacement amplitude and shear rate.The results indicate that the shear stress vs.shear displacement curves under each shear cycle and the peak shear strength vs.cyclic number curves of the studied DDJMs are between those of DIJMs with siltstone and mudstone,while closer to those of DIJMs with mudstone.The peak shear strengths of DDJMs exhibit an initial rapid decline followed by a gradual decrease with the cyclic number and the decrease rate varies from 6%to 55.9%for samples with varied surface morphology under different testing conditions.The normal stress,joint surface morphology,shear displacement amplitude and shear rate collectively influence the shear strength deterioration of DDJM under cyclic shear loading,with the degree of influence being greater for larger normal stress,rougher surface morphology,larger shear displacement amplitude and faster shear rate.
基金Supported by National Science and Technology Support Program of China:Vibration and Noise Reduction Technology Research and Application of Bulldozers and Other Earth Moving Machinery(Grant No.2015BAF07B04)
文摘To understand the engine main bearings' working condition is important in order to improve the performance of engine. However, thermal effects and thermal effect deformations of engine main bearings are rarely considered simultaneously in most studies. A typical finite element model is selected and the effect of thermoelastohydrodynamic(TEHD) reaction on engine main bearings is investigated. The calculated method of main bearing's thermal hydrodynamic reaction and journal misalignment effect is finite difference method, and its deformation reaction is calculated by using finite element method. The oil film pressure is solved numerically with Reynolds boundary conditions when various bearing characteristics are calculated. The whole model considers a temperature-pressure-viscosity relationship for the lubricant, surface roughness effect, and also an angular misalignment between the journal and the bearing. Numerical simulations of operation of a typical I6 diesel engine main bearing is conducted and importance of several contributing factors in mixed lubrication is discussed. The performance characteristics of journal misaligned main bearings under elastohydrodynamic(EHD) and TEHD loads of an I6 diesel engine are received, and then the journal center orbit movement, minimum oil film thickness and maximum oil film pressure of main bearings are estimated over a wide range of engine operation. The model is verified through the comparison with other present models. The TEHD performance of engine main bearings with various effects under the influences of journal misalignment is revealed, this is helpful to understand EHD and TEHD effect of misaligned engine main bearings.
基金The National Basic Research Program(973 Program)of China under contract No.2009CB219401Science and Technology Program of Guangzhou under contract No.201505041038084+2 种基金the Open Fund of State Key Laboratory of Oil and Gas Reservoir Geology and Exploitation(Southwest Petroleum University)under contract No.PLN1401the Key Laboratory of Gas Hydrate,Ministry of Land and Resources under contract No.SHW(2014)-DX-01the State Key Laboratory Breeding Base of Nuclear Resources and Environment,East China Institute of Technology under contract No.NRE1302
文摘The deep-water area of the northern South China Sea, which has active and complicated tectonics, is rich in natural gas and gas hydrate. While the tectonic characteristics is different obviously between the east and the west because of the special tectonic position and tectonic evolution process. In terms of submarine geomorphology, the eastern shelf-slope structure in Pearl River Mouth Basin is characterized by having wide sub-basins and narrow intervening highs, whereas the western (Qiongdongnan Basin) structure is characterized by narrow sub- basins and wide uplift. As to the structural features, the deep-water sags in the east are all structurally half- grabens, controlled by a series of south-dipping normal faults. While the west sags are mainly characterised by graben structures with faulting in both the south and north. With regards to the tectonic evolution, the east began neotectonic activity when the post-rifting stage had completed at the end of the Middle Miocene. In the Baiyun Sag, tectonic activity became strong and was characterised by rapid subsidence and obvious faulting. Whereas in the west, neotectonic activity began at the end of the Late Miocene with rapid deposition and weak fault activity.
基金supported by a grant from the University of Oslo of Norway for the research collaboration between National Center for Women and Children’s Health of Chinese Center for Disease Control and Prevention and Faculty of Medicine of University of Oslo
文摘China bears a large burden of global maternal mortality, and the largest burden of maternal deaths in China is in poor western provinces. This study aimed to investigate the trends in maternal mortality and its associated factors in Guizhou province of western China between 1996 and 2009, and examine differences between minority and non-minority counties. A population-based, longitudinal, retrospective study was performed in a poor western province of China with a considerably large ethnic minority population. All 86 counties/districts of Guizhou were included with population at county, township and village level. Maternal mortality data were collected from routine reporting database of Guizhou Provincial Health Bureau. Trend and comparative analyses and multivariate linear regression analyses were performed using SPSS 17.0. Maternal mortality ratio(MMR) and its change over time, differences between ethnic groups were analyzed. A declining trend in maternal mortality and rising trend in hospital delivery in Guizhou was observed; ethnic differences between two ethnic groups persisted. The reduction in maternal mortality between 1996 and 2009 was related with increased gross domestic product, decreased male illiteracy rate, and increased hospital delivery rate. We found the declining trends in maternal mortality in Guizhou with persisting ethnic differences. The declining trends are related with economic development, hospital delivery and male illiteracy. Effective health education on maternal health is urgently needed for the minority groups, and basic education for the new generation should be enhanced to eradicate the illiteracy.
文摘This paper describes systematic measurement of fiber migration and distribution pattern of twist at different radial positions of rotor spun yarn mixed tracer fiber by Hi-Scope Video Microscope System. The positions of tracer fibers were measured in three dimensions accurately, and the migration index and the twist distribution at different radial positions of rotor yarn were calculated and analyzed. This research result serves to provide useful references for further study on the structural mechanics of rotor spun yarn.
文摘Carbon Nano-Tube Field Effect Transistors(CNTFETs) are being widely studied as possible successors to silicon MOSFETs.Using current mode has many advantages such as performing sum operation by means of a simple wired connection.Also,direction of the current can be used to exhibit the sign of digits.It is expected that the advantages of current mode approaches will become even more important with increased speed requirements and decreased supply voltage.In this paper,we present five new circuit designs for differential absolute value in current mode logic which have been simulated by CNTFET model.The considered base current for this model is 2 μA and supply voltage is 0.9 V.In all of our designs we used N-type CNTFET current mirrors which operate as truncated difference circuits.The operation of Differential Absolute Value circuit calculates the difference between two input currents and our circuit designs are operate in 8 logic levels.
基金This work is supported by the Major State Basic Research Program of China (19990328), the National Tackling Key Problem Program, the National Science Foundation of China (10271066 and 0372052), and the Doctorate Foundation of the Ministry of Education of China (20030422047).
文摘Characteristic finite difference fractional step schemes are put forward. The electric potential equation is described by a seven-point finite difference scheme, and the electron and hole concentration equations are treated by a kind of characteristic finite difference fractional step methods. The temperature equation is described by a fractional step method. Thick and thin grids are made use of to form a complete set. Piecewise threefold quadratic interpolation, symmetrical extension, calculus of variations, commutativity of operator product, decomposition of high order difference operators and prior estimates are also made use of. Optimal order estimates in l2 norm are derived to determine the error of the approximate solution. The well-known problem is thorongley and completely solred.
基金Study was supported by the National Natural Science Foundation of China(21871155)the K.C.Wong Magna Fund in Ningbo University,Fan 3315 PlanYongjiang Scholar Plan~~
文摘It is still a great challenge to effectively optimize the electronic structure of photocatalysts for the sustainable and efficient conversion of solar energy to H2 energy.To resolve this issue,we report on the optimization of the electronic structure of hollow-concave carbon nitride(C3N4)by deviating the sp2-hybridized structure of its tri-s-triazine component from the two-dimensional plane.The embedded CuInS2 into C3N4(CuInS2@C3N4)demonstrates an increased light-capturing capability and the promoted directional transfer of the charge carrier.Research results reveal that the hollow structure with an apparent potential difference between the concave and convex C3N4 drives the directional transfer of the photoinduced electrons from the Cu 2p orbital of CuInS2 to the N 1s orbital of C3N4 with the S-scheme principle.The H2 evolution efficiency over CuInS2@C3N4 is up to 373μmol?h^-1 g^-1 under visible irradiation,which is 1.57 and 1.35 times higher than those over the bulk g-C3N4 with 1 wt%Pt(238μmol?h^-1 g^-1)and g-C3N4 with 3 wt%Pd(276μmol?h^-1 g^-1),respectively.This suggests that the apparent potential difference of the hollow C3N4 results in an efficient reaction between the photogenerated electrons and H2O.This work supplies a new strategy for enhancing the sustainable solar conversion performance of carbon nitride,which can also be suitable for other semiconductors.
基金supported by the National Natural Science Foundation of China [82073566 and 82073578]the Program for Excellent Young Talents in College and University of Anhui Province [gxyq2019014]+1 种基金the Clinical Scientific Research Project of Anhui Medical University [2020xkj161]the Anhui Medical University Clinical Pharmacology and Pharmacology Co-construction Project (2020)
文摘Objective Prenatal phthalate exposure has been associated with placental inflammatory factors and infant allergic rhinitis(AR).However,the results are inconclusive.We designed a population-based cohort study to examine the effects of placental inflammatory biomarkers on the sex-dependent associations between maternal phthalate exposure and infant AR.Methods A total of 2,348 pregnant women from Ma’anshan,Anhui Province,China,who were screened before antenatal visits and met the inclusion criteria,were included in the present study.We assessed AR in their offspring aged 36 months with a questionnaire.Quantitative PCR was performed to measure placental inflammatory factor m RNAs.The independent samples t-test and multivariable logistic regression were used to determine the associations between infant AR and maternal phthalates.Results Childhood AR may be related to education and family monthly income(P = 0.01).The phthalate metabolites,mono(2-ethylhexyl) phthalate(MEHP),mono(2-ethyl-5-hydroxyl) phthalate(MEHHP),in pregnant women were associated with a significantly increased risk for infant AR in males[P < 0.05;odds ratio(OR):1.285;95% confidence interval(CI):1.037-1.591,and OR:1.232,95% CI:1.008-1.507,respectively],but not females.Additionally,irritably-increased expression levels of HO-1 and IL-4 were associated with AR in male infants(OR:1.175;95% CI:1.038-1.329 and OR:1.181;95% CI:1.056-1.322,respectively).The association between maternal urinary MEHHP and placental HO-1 was marginally significant according to mediation analysis.Conclusion The associations of maternal MEHHP and MEOHP levels with fetal AR in males were significant.Placental HO-1 was a fractional mediator in the associations between MEHHP and AR.Thus,the placenta should be further investigated as a potential mediator of maternal exposure-induced disease risk in children.
文摘A modified alternating direction implicit algorithm is proposed to solve the full-vectorial finite-difference beam propagation method formulation based on H fields. The cross-coupling terms are neglected in the first sub-step, but evaluated and doubly used in the second sub-step. The order of two sub-steps is reversed for each transverse magnetic field component so that the cross-coupling terms are always expressed in implicit form, thus the calculation is very efficient and stable. Moreover, an improved six-point finite-difference scheme with high accuracy independent of specific structures of waveguide is also constructed to approximate the cross-coupling terms along the transverse directions. The imaginary-distance procedure is used to assess the validity and utility of the present method. The field patterns and the normalized propagation constants of the fundamental mode for a buried rectangular waveguide and a rib waveguide are presented. Solutions are in excellent agreement with the benchmark results from the modal transverse resonance method.
文摘The minimal clinically important difference(MCID)represents a pivotal metric in bridging the gap between statistical significance and clinical relevance,addressing the direct impact of medical interventions from the patient's perspective.This comprehensive review analyzes the evolution,applications,and challenges of MCID across medical specialties,emphasizing its necessity in ensuring that clinical outcomes not only demonstrate statistical significance but also offer genuine clinical utility that aligns with patient expectations and needs.We discuss the evolution of MCID since its inception in the 1980s,its current applications across various medical specialties,and the methodologies used in its calculation,highlighting both anchor-based and distribution-based approaches.Furthermore,the paper delves into the challenges associated with the application of MCID,such as methodological variability and the interpretation difficulties that arise in clinical settings.Recommendations for the future include standardizing MCID calculation methods,enhancing patient involvement in setting MCID thresholds,and extending research to incorporate diverse global perspectives.These steps are critical to refining the role of MCID in patient-centered healthcare,addressing existing gaps in methodology and interpretation,and ensuring that medical interventions lead to significant,patient-perceived improvements.
基金Supported by Special Construction Funds for National Rape Industry Technology System(CARS-13)Key Consulting Project of the Chinese Academy of Engineering(4005-35013019)
文摘To clarify the determinant factors and inter-group differences of Chinese urban residents' edible vegetable oil consuming behavior is very important for us to understand their consumption features of edible vegetable oil,so as to guide their consuming behavior and improve China's vegetable oil industry security.In this article,urban residents of China's three traditional vegetable oil main production areas have been chosen as study objects,and multiple linear regression and one-way ANOVA have been used to do empirical analysis on the determinant factors and inter-group differences of their edible vegetable oil consuming behavior.The results indicate that the edible vegetable oil consuming behavior of urban residents from China's three traditional vegetable oil main production areas show a trend of diversification;" publicity measures"," preference evaluation"," personal characteristics" and " family characteristics" remarkably affect urban residents' edible vegetable oil consuming behavior and show obvious provincial characteristics.In addition,urban residents from different groups show differences in terms of " publicity measures" and " preference evaluation".
基金supported by the National Natural Science Foundation of China(Grant No.41471131)the Training Program for 100 Young Academic Leaders of Nankai University
文摘The coordinated development between touristization and urbanization is the key to optimizing regional industrial structure and building a long-term dynamic mechanism for urbanization. Based on constructing the measurement index system of touristization and urbanization level, the evaluation model on the coupled and coordinated degree is used in this paper to measure the inter-provincial pattern of the coupled and coordinated relationship between touristization and urbanization in 31 provinces and autonomous regions in China. The results show that the coupled and coordinated relationship between touristization and urbanization is significantly different in different regions, which presents a gradient decline pattern of the highest in the east, the lower in the middle and the lowest in the west. In the future, measures should be taken to promote the coordinated development between touristization and urbanization in accordance with the regional differences and actual development needs.
基金supported by the Strategic Prior-ity Research Program of Chinese Academy of Sciences(Grant No.XDA20020402)the Second Tibetan Plateau Scientific Expedition and Research Program(Grant No.2019QZKK0405)+1 种基金the National Natu-ral Science Foundation of China(Grant No.41861134038)and the Fundamental Research Funds for the Central Universities of China.
文摘Ecosystem Services(ES)are common-pool resources that can be valued by people’s willingness to pay(WTP).In contrast to place-based WTP research at the community-level,the stakeholders tend to be geographically diverse,and the benefits are not spatially apparent on the national level.Aiming to find the geographical diversity of the WTP for ES at the large scale,this study implemented an online survey of more than 25,000 samples to detect the WTP of Chinese people for water conservation,soil retention,carbon fixation,pollution decomposition,biodiversity conservation,and aesthetic existence of the Tibetan Plateau.The results showed the top limit of payments was 1,080.95 CNY/year/capita on average,and people would like to pay 172.40 CNY/year/capita for water conservation,which is the highest among the six ES.The percent of people“Aged 16–35”,“Government agency staff”and“Know WTP”influenced payments at provincial level.On an individual level,people’s knowledge and attitudes directly drove the payment amounts,as well as their ecosystem management decisions.Consequently,geographical diversity of the payment for ES exists in China,and in contrast to the objective social structure and spatial accessibility of ES,people’s knowledge and attitudes were the main driving forces of this geographical diversity.These findings suggest that a bottom-up adaptive governance approach is encouraged for managing common pool resources in developing countries.
基金Supported by grants from the Nanchong City School Cooperation Project(No.18SXHZ0542)Hubei Chen Xiaoping Science and Technology Development Foundation Project(No.CXPJJH11900002-037)Sichuan Medical Research Youth Innovation Project(No.Q18031).
文摘Objective To explore the differences in three different registration methods of cone beam computed tomography(CBCT)-guided down-regulated intense radiation therapy for lung cancer as well as the effects of tumor location,treatment mode,and tumor size on registration.Methods This retrospective analysis included 80 lung cancer patients undergoing radiotherapy in our hospital from November 2017 to October 2019 and compared automatic bone registration,automatic grayscale(t+r)registration,and automatic grayscale(t)positioning error on the X-,Y-,and Z-axes under three types of registration methods.The patients were also grouped according to tumor position,treatment mode,and tumor size to compare positioning errors.Results On the X-,Y-,and Z-axes,automatic grayscale(t+r)and automatic grayscale(t)registration showed a better trend.Analysis of the different treatment modes showed differences in the three registration methods;however,these were not statistically significant.Analysis according to tumor sizes showed significant differences between the three registration methods(P<0.05).Analysis according to tumor positions showed differences in the X-and Y-axes that were not significant(P>0.05),while the autopsy registration in the Z-axis showed the largest difference in the mediastinal and hilar lymph nodes(P<0.05).Conclusion The treatment mode was not the main factor affecting registration error in lung cancer.Three registration methods are available for tumors in the upper and lower lungs measuring<3 cm;among these,automatic gray registration is recommended,while any gray registration method is recommended for tumors located in the mediastinal hilar site measuring<3 cm and in the upper and lower lungs≥3 cm.
文摘An idea on interfacial equilibrium-potential differences () which are generated for the extraction of univalent metal picrate (MPic) and divalent ones (MPic2) by crown ethers (L) into high-polar diluents was improved. These potentials were clarified with some experimental extraction-data reported before on the M = Ag(I), Ca(II), Sr(II) and Ba(II) extraction with 18-crown-6 ether (18C6) and benzo-18C6 into 1,2-dichloroethane (DCE) and nitrobenzene (NB). Consequently, it was demonstrated that the? values from the extraction-experimentally obtained logKD,Pic ones are in agreement with or close to those calculated from charge balance equations in many cases, where the symbol, KD,Pic, denotes an individual distribution constant of Pic﹣ into the DCE or NB phase. Also, it was experimentally shown that extraction constants based on the overall extraction equilibria do not virtually contain the? terms in their functional expressions.
文摘Both Jane Austen and Eileen Chang are popular female writers.However they endowed their heroines with differentfates:Elizabeth in Pride and Prejudice earns a happily-ever-after with her Mr.Right,while Gu Manlu in Eighteen Springs has toembrace death long before her time.They are destined due to their different family backgrounds and different characters which aredepicted in the novels.