期刊文献+
共找到2,000篇文章
< 1 2 100 >
每页显示 20 50 100
ONECUT2高表达介导胃癌复发患者5-FU化疗耐药
1
作者 朱海峰 陈述 +1 位作者 龙卫国 王旭 《江苏大学学报(医学版)》 CAS 2024年第1期19-24,共6页
目的:探究One cut结构域家族成员2(ONECUT2)是否可以作为对5-FU耐药的胃癌复发患者的治疗靶点。方法:利用癌症基因组图谱(TCGA)数据库分析ONECUT2基因在胃癌患者及胃癌复发患者的表达情况。利用基因集富集分析(GSEA)评估TCGA数据库中ONE... 目的:探究One cut结构域家族成员2(ONECUT2)是否可以作为对5-FU耐药的胃癌复发患者的治疗靶点。方法:利用癌症基因组图谱(TCGA)数据库分析ONECUT2基因在胃癌患者及胃癌复发患者的表达情况。利用基因集富集分析(GSEA)评估TCGA数据库中ONECUT2表达量与药物代谢相关生物学过程的相关性。利用CCK-8细胞毒性实验评估胃癌细胞敲低或过表达ONECUT2对5-FU的耐药情况。分析30例胃癌术后复发患者ONECUT2表达量与5-FU治疗效果的相关性。结果:TCGA数据库分析显示,在经受过化疗且复发的胃癌患者中,ONECUT2高表达的患者无病间隔期(disease-free interval,DFI)更短。GSEA分析结果表明,ONECUT2高表达与异生药物代谢通路呈正相关,这提示可能与胃癌患者的耐药相关。体外实验中,敲低ONECUT2降低胃癌细胞对5-FU的半数抑制浓度(IC_(50))值;反之,过表达ONECUT2增加细胞对5-FU的IC_(50)值。30例胃癌复发患者对5-FU的药物敏感性与ONECUT2表达量相关。结论:胃癌复发患者的ONECUT2表达量更高,ONECUT2高表达与胃癌复发患者的5-FU耐药相关,可能是潜在的治疗靶点。 展开更多
关键词 One cut结构域家族成员2 胃癌复发 5-FU耐药 GSEA 细胞毒性 半数抑制浓度
下载PDF
Heavy Smokers Who Cut Back Still Take in More Toxins than Light Smokers
2
作者 张卫红 《科技英语学习》 2007年第1期26-28,共3页
对于老烟枪们来说,只要减少所吸香烟的数量是否就能相应减少有毒物质的摄入,从而减轻对人体的危害呢?研究人员的最新成果发现,并非如此。烟瘾很大的人,即使减少了吸烟数量,他们的身体仍会通过增加抽吸香烟(或其烟雾)的频率等方式尽量摄... 对于老烟枪们来说,只要减少所吸香烟的数量是否就能相应减少有毒物质的摄入,从而减轻对人体的危害呢?研究人员的最新成果发现,并非如此。烟瘾很大的人,即使减少了吸烟数量,他们的身体仍会通过增加抽吸香烟(或其烟雾)的频率等方式尽量摄入能够满足他们身体曾经需要的量。看来戒烟必须彻底。 展开更多
关键词 Heavy Smokers Who cut back Still Take in More Toxins than Light Smokers
原文传递
Instability mechanism of mining roadway passing through fault at different angles in kilometre-deep mine and control measures of roof cutting and NPR cables 被引量:2
3
作者 SUN Xiaoming WANG Jian +6 位作者 ZHAO Wenchao MING Jiang ZHANG Yong LI Zhihu MIAO Chengyu GUO Zhibiao HE Manchao 《Journal of Mountain Science》 SCIE CSCD 2024年第1期236-251,共16页
The angle α between the fault strike and the axial direction of the roadway produces different damage characteristics. In this paper, the research methodology includes theoretical analyses, numerical simulations and ... The angle α between the fault strike and the axial direction of the roadway produces different damage characteristics. In this paper, the research methodology includes theoretical analyses, numerical simulations and field experiments in the context of the Daqiang coal mine located in Shenyang, China. The stability control countermeasure of "pre-splitting cutting roof + NPR anchor cable"(PSCR-NPR) is simultaneously proposed. According to the different deformation characteristics of the roadway, the faults are innovatively classified into three types, with α of type I being 0°-30°, α of type II being 30°-60°, and α of type III being 60°-90°. The full-cycle stress evolution paths during mining roadway traverses across different types of faults are investigated by numerical simulation. Different pinch angles α lead to high stress concentration areas at different locations in the surrounding rock. The non-uniform stress field formed in the shallow surrounding rock is an important reason for the instability of the roadway. The pre-cracked cut top shifted the high stress region to the deep rock mass and formed a low stress region in the shallow rock mass. The high prestressing NPR anchor cable transforms the non-uniform stress field of the shallow surrounding rock into a uniform stress field. PSCR-NPR is applied in the fault-through roadway of Daqiang mine. The low stress area of the surrounding rock was enlarged by 3-7 times, and the cumulative convergence was reduced by 45%-50%. It provides a reference for the stability control of the deep fault-through mining roadway. 展开更多
关键词 Kilometre-deep mine Fault Mining roadway Failure mechanism Pre-splitting cutting roof High pre-stress NPR anchor cable
下载PDF
Cuttings transport: Back reaming analysis based on a coupled layering-sliding mesh method via CFD
4
作者 Na Zhu Shi-Dong Ding +2 位作者 Xiao-Lei Shi Wen-Jun Huang De-Li Gao 《Petroleum Science》 SCIE EI CAS CSCD 2023年第6期3673-3686,共14页
Inadequate hole cleaning is one of the main reasons for inefficient operations in extended-reach drilling.The mechanism of cuttings transport under the back reaming operation,which is frequently adopted to remove the ... Inadequate hole cleaning is one of the main reasons for inefficient operations in extended-reach drilling.The mechanism of cuttings transport under the back reaming operation,which is frequently adopted to remove the cuttings,has been investigated in this study.To this end,a coupled layering-sliding mesh method with the Eulerian-Granular approach has been established innovatively.The dynamic layering method has been employed to simulate the axial motion of the pipe,whereas the sliding mesh method has been used to simulate the pipe rotation.The back reaming operation of a connector-furnished pipe has been simulated,and the sensitive parameter analysis has been conducted.The results thus obtained demonstrate that the increase in the initial bed height,inclination,and the diameter and length of the connector causes a significant increase in the cuttings concentration.In addition,the cuttings concentration is observed to decrease significantly with the pipe rotation speed.Furthermore,two main factors contribute towards the cuttings accumulation around the connector,namely,the difference in the cross-sectional area and the pushing effect of the connector—like a“bulldozer”.The“bulldozer”effect of the connector dominates when the tripping velocity is significant compared to the velocity of the cuttings.Conversely,the effect of the difference in the cross-sectional area becomes the leading factor for cuttings accumulation.The“bulldozer”effect of the connector causes a more severe impact on hole cleaning.In both cases,increasing the tripping velocity only mildly affects the cuttings concentration.It is therefore suggested that the tripping velocity should be slower than that of the sand during the back reaming operation.Furthermore,increased fluid velocity might lead to a higher accumulated cuttings concentration around the connector when the cuttings bed has not entirely passed through the connector.A significant flow rate can be safely applied after the cuttings have passed through the connector furnished with a large diameter,such as the bottom hole assembly.This exploration serves as an essential guide to predicting and controlling tight spots while back reaming. 展开更多
关键词 Drill cuttings transport back reaming Layering-sliding mesh Hole cleaning CONNECTOR
下载PDF
Prediction of SMILE surgical cutting formula based on back propagation neural network
5
作者 Dong-Qing Yuan Fu-Nan Tang +5 位作者 Chun-Hua Yang Hui Zhang Ying Wang Wei-Wei Zhang Liu-Wei Gu Qing-Huai Liu 《International Journal of Ophthalmology(English edition)》 SCIE CAS 2023年第9期1424-1430,共7页
AIM:To predict cutting formula of small incision lenticule extraction(SMILE)surgery and assist clinicians in identifying candidates by deep learning of back propagation(BP)neural network.METHODS:A prediction program w... AIM:To predict cutting formula of small incision lenticule extraction(SMILE)surgery and assist clinicians in identifying candidates by deep learning of back propagation(BP)neural network.METHODS:A prediction program was developed by a BP neural network.There were 13188 pieces of data selected as training validation.Another 840 eye samples from 425 patients were recruited for reverse verification of training results.Precision of prediction by BP neural network and lenticule thickness error between machine learning and the actual lenticule thickness in the patient data were measured.RESULTS:After training 2313 epochs,the predictive SMILE cutting formula BP neural network models performed best.The values of mean squared error and gradient are 0.248 and 4.23,respectively.The scatterplot with linear regression analysis showed that the regression coefficient in all samples is 0.99994.The final error accuracy of the BP neural network is-0.003791±0.4221102μm.CONCLUSION:With the help of the BP neural network,the program can calculate the lenticule thickness and residual stromal thickness of SMILE surgery accurately.Combined with corneal parameters and refraction of patients,the program can intelligently and conveniently integrate medical information to identify candidates for SMILE surgery. 展开更多
关键词 small incision lenticule extraction back propagation neural network deep learning cutting formula PREDICTION
下载PDF
Hole cleaning evaluation and installation spacing optimization of cuttings bed remover in extended-reach drilling
6
作者 Shuo Peng Wen-Jun Huang De-Li Gao 《Petroleum Science》 SCIE EI CAS CSCD 2024年第3期2005-2022,共18页
In extended-reach or long-horizontal drilling,cuttings usually deposit at the bottom of the annulus.Once cuttings accumulate to a certain thickness,complex problems such as excessive torque and drag,tubing buckling,an... In extended-reach or long-horizontal drilling,cuttings usually deposit at the bottom of the annulus.Once cuttings accumulate to a certain thickness,complex problems such as excessive torque and drag,tubing buckling,and pipe stuck probably occur,which results in a lot of non-productive time and remedial operations.Cuttings bed remover can efficiently destroy deposited cuttings in time through hydraulic and mechanical stirring effects.This paper aims to build a method for hole cleaning evaluation and installation spacing optimization of cuttings bed remover to improve the wellbore cleaning effect.Firstly,a Computational Fluid Dynamics approach with Eulerian—Eulerian multiphase model was utilized to investigate the mechanism of cuttings transportation,and a new type of cuttings bed remover was designed.Next,an evaluation method of hole cleaning effect of remover was established.After that,the effects of several drilling parameters on hole cleaning including flow rate of drilling fluid,rotational speed of drillpipe,rate of penetration,wellbore size,rheological property of drilling fluid,and remover eccentricity on the performance of cuttings bed remover were investigated.The results demonstrate that the new type of remover with streamline blade performs better than conventional removers.The efficiency of hole cleaning is greatly improved by increasing the rotational speed of drillpipe,flow rate of drilling fluid,remover eccentricity,and 6 rpm Fann dial reading for drilling fluid.While higher rate of penetration and large wellbore size result in worse hole cleaning.These findings can serve as an important guide for the structure optimization design of cuttings bed remover and installation spacing of removers. 展开更多
关键词 Extended-reach drlling Drilling hydraulics cuttings transport Hole cleaning cuttings bed remover
下载PDF
Unraveling engineering disturbance effects on deformation in red-bed mudstone railway cuttings:incorporating crack-facilitated moisture diffusion
7
作者 HUANG Kang DAI Zhangjun +3 位作者 YAN Chengzeng YAO Junkai CHI Zecheng CHEN Shanxiong 《Journal of Mountain Science》 SCIE CSCD 2024年第5期1663-1682,共20页
Red-bed mudstone, prevalent in southwest China, poses a formidable challenge due to its hydrophilic clay minerals, resulting in expansion, deformation, and cracking upon exposure to moisture. This study addresses upli... Red-bed mudstone, prevalent in southwest China, poses a formidable challenge due to its hydrophilic clay minerals, resulting in expansion, deformation, and cracking upon exposure to moisture. This study addresses uplift deformation disasters in high-speed railways by employing a moisture diffusion-deformation-fracture coupling model based on the finite-discrete element method(FDEM). The model integrates the influence of cracks on moisture diffusion. The investigation into various excavation depths reveals a direct correlation between depth and the formation of tensile cracks at the bottom of the railway cutting. These cracks expedite moisture migration, significantly impacting the temporal and spatial evolution of the moisture field. Additionally, crack expansion dominates hygroscopic deformation, with the lateral coordinate of the crack zone determining peak vertical displacement. Furthermore, key factors influencing deformation in railway cuttings, including the swelling factor and initial moisture content at the bottom of the cutting, are explored. The number of tensile and shear cracks increases with greater excavation depth, particularly concerning shear cracks. Higher swelling factors and initial moisture contents result in an increased total number of cracks, predominantly shear cracks. Numerical calculations provide valuable insights, offering a scientific foundation and directional guidance for the precise prevention, control, prediction, and comprehensive treatment of mudstone-related issues in high-speed railways. 展开更多
关键词 Red-bed mudstone Railway cutting FDEM Moisture diffusion DEFORMATION CRACK
下载PDF
Assessing cutter-rock interaction during TBM tunnelling in granite:Large-scale standing rotary cutting tests and 3D DEM simulations
8
作者 Xin Huang Miaoyuan Tang +4 位作者 Shuaifeng Wang Yixin Zhai Qianwei Zhuang Chi Zhang Qinghua Lei 《Journal of Rock Mechanics and Geotechnical Engineering》 SCIE CSCD 2024年第9期3595-3615,共21页
The widespread utilisation of tunnel boring machines(TBMs)in underground construction engineering requires a detailed investigation of the cutter-rock interaction.In this paper,we conduct a series of largescale standi... The widespread utilisation of tunnel boring machines(TBMs)in underground construction engineering requires a detailed investigation of the cutter-rock interaction.In this paper,we conduct a series of largescale standing rotary cutting tests on granite in conjunction with high-fidelity numerical simulations based on a particle-type discrete element method(DEM)to explore the effects of key cutting parameters on the TBM cutter performance and the distribution of cutter-rock contact stresses.The assessment results of cutter performance obtained from the cutting tests and numerical simulations reveal similar dependencies on the key cutting parameters.More specifically,the normal and rolling forces exhibit a positive correlation with penetration but are slightly influenced by the cutting radius.In contrast,the side force decreases as the cutting radius increases.Additionally,the side force shows a positive relationship with the penetration for smaller cutting radii but tends to become negative as the cutting radius increases.The cutter's relative effectiveness in rock breaking is significantly impacted by the penetration but shows little dependency on the cutting radius.Consequently,an optimal penetration is identified,leading to a low boreability index and specific energy.A combined Hertz-Weibull function is developed to fit the cutter-rock contact stress distribution obtained in DEM simulations,whereby an improved CSM(Colorado School of Mines)model is proposed by replacing the original monotonic cutting force distribution with this combined Hertz-Weibull model.The proposed model outperforms the original CSM model as demonstrated by a comparison of the estimated cutting forces with those from the tests/simulations.The findings from this work that advance our understanding of TBM cutter performance have important implications for improving the efficiency and reliability of TBM tunnelling in granite. 展开更多
关键词 Large-scale standing rotary cutting test Discrete element method(DEM)simulation cutter-rock interaction Improved CSM(Colorado School of Mines) model cutting force
下载PDF
Precipitates Generation Mechanism and Surface Quality Improvement for Aluminum Alloy 6061 in Diamond Cutting
9
作者 王海龙 DENG Wenping 王素娟 《Journal of Wuhan University of Technology(Materials Science)》 SCIE EI CAS CSCD 2024年第1期150-159,共10页
To improve the surface quality for aluminum alloy 6061(Al6061) in ultra-precision machining, we investigated the factors affecting the surface finish in single point diamond turning(SPDT)by studying influence of the p... To improve the surface quality for aluminum alloy 6061(Al6061) in ultra-precision machining, we investigated the factors affecting the surface finish in single point diamond turning(SPDT)by studying influence of the precipitates generation of Al6061 on surface integrity and surface roughness.Based on the Johnson-Mehl-Avrami solid phase transformation kinetics equation, theoretical and experimental studies were conducted to build the relationship between the aging condition and the type, size and number of the precipitates for Al6061. Diamond cutting experiments were conducted to machine Al6061 samples under different aging conditions. The experimental results show that, the protruding on the chip surface is mainly Mg_(2)Si and the scratches on the machined surface mostly come from the iron-containing phase(α-, β-AlFeSi).Moreover, the generated Mg_(2)Si and α-, β-AlFeSi affect the surface integrity and the diamond turned surface roughness. Especially, the achieved surface roughness in SPDT is consistent with the variation of the number of AlFeSi and Mg_(2)Si with the medium size(more than 1 μm and less than 2 μm) in Al6061. 展开更多
关键词 Al6061 PRECIPITATES aging treatment diamond cutting surface roughness
下载PDF
Failure mechanism of directional roof cutting and design method optimization
10
作者 HOU Shilin YANG Jun +5 位作者 WANG Yajun CHEN Kuikui ZHANG Jun HE Manchao YANG Gang CHEN Gonghua 《Journal of Mountain Science》 SCIE CSCD 2024年第11期3898-3912,共15页
Directional roof cutting(DRC)is one of the key techniques in non-pillar coal mining with self-formed entries(NCMSE)mining method.Due to the inability to accurately measure the expansion coefficient of the goaf rock ma... Directional roof cutting(DRC)is one of the key techniques in non-pillar coal mining with self-formed entries(NCMSE)mining method.Due to the inability to accurately measure the expansion coefficient of the goaf rock mass,the implementation of this technology often encounters design challenges,leading to suboptimal results and increased costs.This paper establishes a structural analysis model of the goaf working face roof,revealing the failure mechanism of DRC,and clarifies the positive role of DRC in improving the stress of the roadway surrounding rock and reducing the subsidence of the roof through numerical simulation experiments.On this basis,the paper further analyses the roadway pressure and roof settlement under different DRC design heights,and ultimately proposes an optimized design method for the DRC height.The results indicate that the implementation of DRC can significantly optimize the stress environment of the working face roadway surrounding rock.At the same time,during the application of DRC,three scenarios may arise:insufficient,reasonable,and excessive DRC height.Insufficient height will significantly reduce the effectiveness of the technology,while excessive height has little impact on the implementation effect but will greatly increase construction costs and difficulty.Engineering verification shows that the optimized DRC design method proposed in this paper reduces the peak stress of the protective coal pillar in the roadway by 27.2%and the central subsidence of the roof by 41.8%,demonstrating excellent application results.This method provides technical support for the further promotion of NCMSE mining method. 展开更多
关键词 Directional roof cutting Roof structure Failure mechanism Numerical simulation Optimized design method Engineering verification
下载PDF
Concurrent Two-Scale Topology Optimization of Thermoelastic Structures Using a M-VCUT Level Set Based Model of Microstructures
11
作者 Jin Zhou Minjie Shao +1 位作者 Ye Tian Qi Xia 《Computer Modeling in Engineering & Sciences》 SCIE EI 2024年第11期1327-1345,共19页
By analyzing the results of compliance minimization of thermoelastic structures,we observed that microstructures play an important role in this optimization problem.Then,we propose to use a multiple variable cutting(M... By analyzing the results of compliance minimization of thermoelastic structures,we observed that microstructures play an important role in this optimization problem.Then,we propose to use a multiple variable cutting(M-VCUT)level set-based model of microstructures to solve the concurrent two-scale topology optimization of thermoelastic structures.A microstructure is obtained by combining multiple virtual microstructures that are derived respectively from multiple microstructure prototypes,thus giving more diversity of microstructure and more flexibility in design optimization.The effective mechanical properties of microstructures are computed in an off-line phase by using the homogenization method,and then a mapping relationship between the design variables and the effective properties is established,which gives a data-driven model of microstructure.In the online phase,the data-driven model is used in the finite element analysis to improve the computational efficiency.The compliance minimization problem is considered,and the results of numerical examples prove that the proposed method is effective. 展开更多
关键词 Two-scale structure topology optimization multiple variable cutting level set DATA-DRIVEN radial basis function thermoelastic structure
下载PDF
Ground response and failure mechanism of gob-side entry by roof cutting with hard main roof
12
作者 ZHU Heng-zhong XU Lei WEN Zhi-jie 《Journal of Central South University》 SCIE EI CAS CSCD 2024年第7期2488-2512,共25页
This study is the result of long-term efforts of the authors’team to assess ground response of gob-side entry by roof cutting(GSERC)with hard main roof,aiming at scientific control for GSERC deformation.A comprehensi... This study is the result of long-term efforts of the authors’team to assess ground response of gob-side entry by roof cutting(GSERC)with hard main roof,aiming at scientific control for GSERC deformation.A comprehensive field measurement program was conducted to determine entry deformation,roof fracture zone,and anchor bolt(cable)loading.The results indicate that GSERC deformation presents asymmetric characteristics.The maximum convergence near roof cutting side is 458 mm during the primary use process and 1120 mm during the secondary reuse process.The entry deformation is closely associated with the primary development stage,primary use stage,and secondary reuse stage.The key block movement of roof cutting structure,a complex stress environment,and a mismatch in the supporting design scheme are the failure mechanism of GSERC.A controlling ideology for mining states,including regional and stage divisions,was proposed.Both dynamic and permanent support schemes have been implemented in the field.Engineering practice results indicate that the new support scheme can efficiently ensure long-term entry safety and could be a reliable approach for other engineering practices. 展开更多
关键词 gob-side entry by roof cutting ground response failure mechanism following mining states control hard main roof
下载PDF
Yield and Nutritive Values of Semi- and Non-Fall Dormant Alfalfa Cultivars under Late-Cutting Schedule in California’s Central Valley
13
作者 Sultan Begna Dan Putnam +2 位作者 Dong Wang Khaled Bali Longxi Yu 《American Journal of Plant Sciences》 CAS 2024年第10期858-876,共19页
California is one of the major alfalfa (Medicago sativa L) forage-producing states in the U.S, but its production area has decreased significantly in the last couple of decades. Selection of cultivars with high yield ... California is one of the major alfalfa (Medicago sativa L) forage-producing states in the U.S, but its production area has decreased significantly in the last couple of decades. Selection of cultivars with high yield and nutritive value under late-cutting schedule strategy may help identify cultivars that growers can use to maximize yield while maintaining area for sustainable alfalfa production, but there is little information on this strategy. A field study was conducted to determine cumulative dry matter (DM) and nutritive values of 20 semi- and non-fall dormant (FD) ratings (FD 7 and FD 8 - 10, respectively) cultivars under 35-day cut in California’s Central Valley in 2020-2022. Seasonal cumulative DM yields ranged from 6.8 in 2020 to 37.0 Mg·ha−1 in 2021. Four FD 8 - 9 cultivars were the highest yielding with 3-yrs avg. DM greater than the lowest yielding lines by 46%. FD 7 cultivar “715RR” produced the highest crude protein (CP: 240 g·Kg−1) while FD 8 cultivar “HVX840RR” resulted in the highest neutral detergent fiber digestibility (NDFD: 484 g·Kg−1, 7% greater than the top yielding cultivars) but with DM yield intermediate. Yields and NDFD correlated positively but weakly indicating some semi- and non-FD cultivars performing similarly. These results suggest that selecting high yielding cultivars under 35-day cutting schedule strategy can be used as a tool to help growers to maximize yield while achieving good quality forages for sustainable alfalfa production in California’s Central Valley. 展开更多
关键词 ALFALFA Maximizing Yield Nutritive Value CULTIVAR cutting Schedule Production Area California
下载PDF
Experimental investigation on using CO_(2)/H_(2)O emulsion with high water cut in enhanced oil recovery
14
作者 Xi-Dao Wu Peng Xiao +2 位作者 Bei Liu Guang-Jin Chen Jian-Hua Pang 《Petroleum Science》 SCIE EI CAS CSCD 2024年第2期974-986,共13页
CO_(2) emulsions used for EOR have received a lot of interest because of its good performance on CO_(2)mobility reduction.However,most of them have been focusing on the high quality CO_(2) emulsion(high CO_(2) fractio... CO_(2) emulsions used for EOR have received a lot of interest because of its good performance on CO_(2)mobility reduction.However,most of them have been focusing on the high quality CO_(2) emulsion(high CO_(2) fraction),while CO_(2) emulsion with high water cut has been rarely researched.In this paper,we carried out a comprehensive experimental study of using high water cut CO_(2)/H_(2)O emulsion for enhancing oil recovery.Firstly,a nonionic surfactant,alkyl glycosides(APG),was selected to stabilize CO_(2)/H_(2)O emulsion,and the corresponding morphology and stability were evaluated with a transparent PVT cell.Subsequently,plugging capacity and apparent viscosity of CO_(2)/H_(2)O emulsion were measured systematically by a sand pack displacement apparatus connected with a 1.95-m long capillary tube.Furthermore,a high water cut(40 vol%) CO_(2)/H_(2)O emulsion was selected for flooding experiments in a long sand pack and a core sample,and the oil recovery,the rate of oil recovery,and the pressure gradients were analyzed.The results indicated that APG had a good performance on emulsifying and stabilizing CO_(2) emulsion.An inversion from H_(2)O/CO_(2) emulsion to CO_(2)/H_(2)O emulsion with the increase in water cut was confirmed.CO_(2)/H_(2)O emulsions with lower water cuts presented higher apparent viscosity,while the optimal plugging capacity of CO_(2)/H_(2)O emulsion occurred at a certain water cut.Eventually,the displacement using CO_(2)/H_(2)O emulsion provided 18.98% and 13.36% additional oil recovery than that using pure CO_(2) in long sand pack and core tests,respectively.This work may provide guidelines for EOR using CO_(2) emulsions with high water cut. 展开更多
关键词 CO_(2)/H_(2)O emulsion High water cut CO_(2) mobility control Enhanced oil recovery
下载PDF
Endoscopic radial incision and cutting method for adult congenital duodenal webs:A case report
15
作者 Hyun Deok Shin 《World Journal of Clinical Cases》 SCIE 2024年第18期3622-3628,共7页
BACKGROUND Congenital duodenal webs are rare in adults and can lead to various symptoms such as nausea,vomiting,and postprandial fullness.The treatment for this disease is mostly surgical.Endoscopic treatment techniqu... BACKGROUND Congenital duodenal webs are rare in adults and can lead to various symptoms such as nausea,vomiting,and postprandial fullness.The treatment for this disease is mostly surgical.Endoscopic treatment techniques have been developed and attempted for this disease.Endoscopic radial incision and cutting(RIC)techniques are reportedly very effective in benign anastomotic stricture.This case report highlights the effectiveness and safety of endoscopic RIC as a minimally invasive treatment for adult congenital duodenal webs.CASE SUMMARY A 23-year-old female patient with indigestion was referred to a tertiary hospital.The patient complained of postprandial fullness in the epigastric region.Previous physical examinations or blood tests indicated no abnormalities.Computed tomography revealed an eccentric broad-based delayed-enhancing mass-like lesion in the second portion of the duodenum.Endoscopy showed an enlarged gastric cavity and a significantly dilated duodenal bulb;a very small hole was observed in the distal part of the second portion,and scope passage was not possible.Gastrografin upper gastrointestinal series was performed,revealing an intraduodenal barium contrast-filled sac with a curvilinear narrow radiolucent rim,a typical"windsock"sign.Endoscopic RIC was performed on the duodenal web.The patient recovered uneventfully.Follow-up endoscopy showed a patent duodenal lumen without any residual stenosis.The patient reported complete resolution of symptoms at the 18-month follow-up.CONCLUSION Endoscopic RIC may be an effective treatment for congenital duodenal webs in adults. 展开更多
关键词 Congenital duodenal web Endoscopic treatment Radial incision and cutting method Surgery Case report
下载PDF
Effects of Different Seasons on Cutting Propagation of Five Citrus Rootstocks
16
作者 Liying GUO Yun CHEN +5 位作者 Meiling LI Yilin CHEN Wenwen HUANG Yuanmeng YU Guochan HUANG Qianhua JI 《Asian Agricultural Research》 2024年第11期29-35,43,共8页
[Objectives]To explore the cutting propagation mode of citrus rootstock,improve the survival rooting rate of citrus rootstock,and provide theoretical guidance and technical reference for the rooting research of diffic... [Objectives]To explore the cutting propagation mode of citrus rootstock,improve the survival rooting rate of citrus rootstock,and provide theoretical guidance and technical reference for the rooting research of difficult-to-root plants such as citrus.[Methods]Five citrus rootstocks Citrus tangerina Tanaka‘Hongju’,Citrus haniana Hort‘Suanju’,Citrus limonia Osbeck‘Hongningmeng’,Citrus sinensis×Poncirus trifoliata‘Zhicheng’and Poncirus trifoliate(L)Raf.‘Zhike’were used as experimental materials to select the suitable cutting substrate for citrus rootstocks by measuring the physical properties of the substrate.Cutting was carried out in spring,summer,autumn and winter respectively.After cutting,the morphological changes of cuttings were observed regularly,and the callus rate,germination rate and rooting rate of cuttings were recorded.[Results]The best substrate for citrus rootstock cutting was peat soil,vermiculite and fine river sand(2:1:1).The callus of citrus rootstock in different cutting seasons began to appear in 10-22 d,and the callus rate reached 55%-100%.In terms of budding,the budding time was the earliest in summer and autumn,and slightly later in spring and winter;the germination rate of C.limonia Osbeck‘Hongningmeng’was the highest,and the germination rate of C.sinensis×P.trifoliata‘Zhicheng’and P.trifoliate(L)Raf.‘Zhike’was lower;in terms of rooting,C.limonia Osbeck‘Hongningmeng’had the earliest rooting time and the highest rooting rate and could reach 100%in all seasons;the rooting rate of C.tangerina Tanaka‘Hongju’was 50%-80%;the rooting rate of C.haniana Hort‘Suanju’was 60%-80%;C.sinensis×P.trifoliata‘Zhicheng’and P.trifoliate(L)Raf.‘Zhike’showed the earliest rooting time and the highest rooting rate in summer,and the latest rooting time and the lowest rooting rate in winter,which were only 14.5%.Therefore,different citrus rootstock varieties should choose the appropriate cutting time according to their own characteristics.[Conclusions]The results of this study can provide a scientific basis for a large number of cutting propagation of different citrus rootstocks,and have practical guiding significance for large-scale planting. 展开更多
关键词 CITRUS cutting propagation Rooting rate VARIETIES
下载PDF
Cutting Propagation Technique of Pennisetum purpureum Schum
17
作者 Yuanbin HU Jing ZHANG +2 位作者 Yanan LIU Xiaoyu LIANG Yang JI 《Plant Diseases and Pests》 2024年第2期27-31,共5页
[Objectives]The paper was to study the cutting propagation technique of Pennisetum purpureum Schum and to provide a technical reference for establishing an efficient cutting propagation method.[Methods]Six treatments ... [Objectives]The paper was to study the cutting propagation technique of Pennisetum purpureum Schum and to provide a technical reference for establishing an efficient cutting propagation method.[Methods]Six treatments were set up using P.purpureum cv.Guiminyin and P.purpureum cv.Guimu-1 as test materials,including 1-node oblique insertion,1-node oblique insertion+rooting powder,1-node transverse burial,2-node oblique insertion,2-node oblique insertion+rooting powder and 2-node transverse burial.The following indices were observed and determined for P.purpureum cuttings:emergence rate,rooting rate,root number,longest root length,fresh root weight,plant height,number of tillers,number of leaves,and fresh stem and leaf weight.[Results]In the 2-node cutting+rooting powder treatment,Guiminyin and Guimu-1 exhibited the highest survival rate,root growth indices,and stem and leaf growth indices,with the emergence rates of 94.29%and 90.26%,respectively.The 2-node cutting treatment followed closely behind,while the 1-node cutting treatment had the lowest indices.Under the same treatment,Guimuyin exhibited higher mean values for plant height,number of leaves,fresh stem and leaf weight,longest root length,and fresh root weight compared to Guimu-1.However,it had lower mean number of tillers,and emergence rate and rooting rate of the 1-node cutting treatment compared to Guimu-1.[Conclusions]The P.purpureum cuttings thrived in the 2-node cutting+rooting powder treatment,and the overall cutting effect of Guiminyin was superior to that of Guimu-1. 展开更多
关键词 Pennisetum purpureum Schum cutTING PROPAGATION Emergence rate
下载PDF
Application of Fuyang Paper Cutting Art in Cultural and Creative Design from the Perspective of Rural Revitalization
18
作者 KANG Wenwen 《Journal of Landscape Research》 2024年第3期59-62,共4页
The application significance of Fuyang paper cutting art in cultural and creative design from the perspective of rural revitalization was discussed,and the implementation principles and specific practices of applying ... The application significance of Fuyang paper cutting art in cultural and creative design from the perspective of rural revitalization was discussed,and the implementation principles and specific practices of applying the elements and techniques of Fuyang traditional paper cutting art in cultural and creative products with local features were analyzed to provide reference for rural revitalization and development of cultural industry. 展开更多
关键词 Rural revitalization Fuyang paper cutting Cultural and creative design
下载PDF
Cutting-edge Technological Innovation Outcome Displayed at 2024 Beijing Science and Technology Week
19
作者 Zhang Yida 《China's Foreign Trade》 2024年第3期47-49,共3页
The 2024 National Science and Technology Week and Beijing Science and Technology Week opened in Shougang Park in Shijingshan District from May 25 to June 1.Under the theme of“Carrying forward the spirit of scientists... The 2024 National Science and Technology Week and Beijing Science and Technology Week opened in Shougang Park in Shijingshan District from May 25 to June 1.Under the theme of“Carrying forward the spirit of scientists and inspiring societal innovation,”this event focused on the new-generation IT technology,medical health,energy and technology,modern agriculture and intelligent manufacturing industries. 展开更多
关键词 DISTRICT cutTING opened
下载PDF
Research on the Resistance of Cutting Mechanism of Mining Longitudinal Roadheader
20
作者 Mengjiao NIU Yong ZHAO Yongliang YUAN 《Mechanical Engineering Science》 2024年第1期8-12,共5页
In order to accurately obtain the dynamic characteristics of the cutting mechanism of the mining longitudinal roadheader,combined with the working principle of the mining longitudinal roadheader,the theoretical analys... In order to accurately obtain the dynamic characteristics of the cutting mechanism of the mining longitudinal roadheader,combined with the working principle of the mining longitudinal roadheader,the theoretical analysis and derivation are carried out in detail.By using ADAMS to simulate,the resistance curve and torque curve of the cutting mechanism in different directions are obtained.The results show that ADAMS can effectively predict the excavation resistance and torque of the cutting mechanism of mining longitudinal roadheader,which has certain reference value for future optimization design. 展开更多
关键词 longitudinal roadheader cutting mechanism dynamic characteristics DYNAMICS
下载PDF
上一页 1 2 100 下一页 到第
使用帮助 返回顶部