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Measurement of the Level of Knowledge of the Sands Used in Constructions in Togo
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作者 Ezoba Nayo Kossi Bollanigni Amey +1 位作者 Essé MawuléEdorh Komla Assogba Kassegne 《Journal of Minerals and Materials Characterization and Engineering》 2024年第4期225-235,共11页
Faced with the proliferation of quarries extracting silty sand and river sand used in the building and public works sector in Togo, recognition of the granular properties of these materials remains a major challenge f... Faced with the proliferation of quarries extracting silty sand and river sand used in the building and public works sector in Togo, recognition of the granular properties of these materials remains a major challenge for builders. This study aims to take stock of the use of sand in construction in Togo. One hundred and eighteen (118) sand quarries in operation, including thirty-eight (38) silty sand quarries and eighty (80) river sand quarries, were identified following surveys carried out among stakeholders involved in the chain of construction on 40% of the national territory. It appears from these surveys that river sands (59.43% to 84.68%) are prioritized over silty sands (15.32% to 40.57%). Three (3) main reasons are behind the choice of sand type;namely, proximity (28%), cleanliness (25%), good appearance (25%). These three (03) reasons partly explain the strong dependence of users on the sands located in their vicinity as well as the related expenses. Thus, making data available on the characteristics of sand, the materials most used in construction in Togo, would contribute to improving the housing conditions of the Togolese population. . 展开更多
关键词 SANDS TOGO Reasons for use Construction
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Study of the Evolution of Properties of Concrete Containing Used Tire Aggregates
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作者 Mamery Adama Serifou Ouaga Jean Bruce Nataniel Gboga +1 位作者 Bleh Raoul Ulrich Kouassi Edjikémé Emeruwa 《Geomaterials》 2024年第4期49-58,共10页
Concrete is generally composed of cement, water, gravel, and sand. However, some research focuses on substituting aggregates with waste materials. In this study, used tires are used as a substitute for gravel. Charact... Concrete is generally composed of cement, water, gravel, and sand. However, some research focuses on substituting aggregates with waste materials. In this study, used tires are used as a substitute for gravel. Characteristics such as tensile strength, compressive strength, and porosity were monitored at 7, 14, and 28 days of maturation. The results show that aggregates made from used tires are suitable for concrete production and can replace natural gravel. Regarding the formed concrete, low substitution rates lead to improved concrete properties, but only at an early age. A reaction between the cement and rubber could be the underlying cause. Additionally, the products of this reaction may mitigate the evolution of the compressive strength of the concrete over time. 展开更多
关键词 CONCRETE used Tire POROSITY Mechanical Strength
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Septic shock due to cytomegalovirus colitis associated with rituximab use:A case report
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作者 Siddharth Patel Jordan Jay +2 位作者 Prutha Pathak Mc Anto Antony Mrudula Thiriveedi 《World Journal of Virology》 2025年第1期118-123,共6页
BACKGROUND Cytomegalovirus(CMV)infections can cause significant morbidity and mortality in immunocompromised individuals.CMV targets dysfunctional lymphocytes.Chronic rituximab(RTX)therapy can cause B-lymphocyte dysfu... BACKGROUND Cytomegalovirus(CMV)infections can cause significant morbidity and mortality in immunocompromised individuals.CMV targets dysfunctional lymphocytes.Chronic rituximab(RTX)therapy can cause B-lymphocyte dysfunction,increasing CMV risk.Rarely,CMV infections present with critical illness such as septic shock.CASE SUMMARY A 64-year-old African American woman presented with generalized weakness and non-bloody watery diarrhea of 4-6 weeks duration.She did not have nausea,vomiting or,abdominal pain.She had been on monthly RTX infusions for neuromyelitis optica.She was admitted for septic shock due to pancolitis.Blood investigations suggested pancytopenia and serology detected significantly elevated CMV DNA.Valganciclovir treatment led to disease resolution.CONCLUSION This case illustrates an extremely rare case of CMV colitis associated with RTX use presenting with septic shock.High suspicion for rare opportunistic infections is imperative in individuals with long-term RTX use. 展开更多
关键词 Cytomegalovirus colitis Rituximab use Immunocompromised status Septic shock PANCYTOPENIA Case report
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The Association between Problematic Internet Use,Resilience,and Fatigue in First-Year Medical College Students in China:A Moderated Mediation Model
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作者 Xiumei Chen Xiaobing Lu +6 位作者 Yufu Ning Lifeng Wang Jeffrey H.Gamble Xianhe Chen Xingyong Jiang I-Hua Chen Peijin Lin 《International Journal of Mental Health Promotion》 2025年第1期51-63,共13页
Background:Resilience is crucial for medical college students to thrive in the highly stressful environment of medical education.However,the prevalence of problematic internet use(PIU)in this population may negatively... Background:Resilience is crucial for medical college students to thrive in the highly stressful environment of medical education.However,the prevalence of problematic internet use(PIU)in this population may negatively impact their resilience.This study investigated the influence of problematic online gaming(PG)and problematic social media use(PSMU)on the resilience of medical college students in China.Methods:A sample of 5075 first-year medical college students from four Chinese universities was studied.PG served as the independent variable,resilience as the dependent variable,fatigue as the mediator,and PSMU as the moderator.Structural equation modeling was conducted using LISREL 8.80.Additionally,a moderated mediation model was evaluated using the jAMM module in jamovi 2.6.13.Results:The study’s findings revealed significant negative correlations between resilience and the variables of PG,PSMU,and fatigue.Fatigue mediated the relationship between PG and resilience(B=−0.04,95%CI=[−0.05,−0.03]).PSMU moderated the direct relationship between PG and resilience with the interaction term PG×PSMU significant(B=−0.004,t=−6.501,p<0.001)and the first stage(PG→fatigue)of the mediation with PG×PSMU significant(B=0.055,t=8.351,p<0.001).The detrimental effects of PG on resilience were more pronounced among individuals with lower levels of PSMU.Conclusion:This study concluded that addressing PIU,particularly PG,is essential for fostering resilience in medical college students.While PSMU itself is maladaptive,the underlying social media engagement may serve a protective role through social support in mitigating the adverse effects of PG on resilience. 展开更多
关键词 Problematic internet use problematic online gaming problematic social media use FATIGUE RESILIENCE structural equation modeling conditional mediation
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Survey and Recommendations for Land Use of Agricultural Machinery Service Organization Facilities in Guizhou Province
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作者 Xingyuan QI Chunbo LIU +2 位作者 Zhifei JIN Yingfen WANG Shuyun LIN 《Asian Agricultural Research》 2025年第1期14-17,共4页
With the advancement of agricultural modernization, agricultural machinery service organizations, as an important part of the rural operating entities, show an increasing trend year by year, and need new facilities la... With the advancement of agricultural modernization, agricultural machinery service organizations, as an important part of the rural operating entities, show an increasing trend year by year, and need new facilities land in the process of development and growth. Based on the written survey of 597 agricultural machinery service organizations in Guizhou Province, the demand and demand gap of various facilities land use in agricultural machinery service organizations were analyzed and compared. In addition, based on the field survey and policy background, the main practices and experiences of agricultural machinery service organizations in Guizhou Province in the approval and use of facility land were sorted out, and the problems and causes of large gap in facility agricultural land, lack of standards and difficulty in policy implementation were analyzed. Finally, it recommended that the site selection of agricultural machinery service organization facilities needs to be standardized, the land demand needs to be coordinated, the land scale needs to be scientifically demonstrated, and financial support should be sought to promote Guizhou agricultural machinery service organization to become bigger, better and stronger. 展开更多
关键词 Agricultural machinery service organization Facility land use Current situation survey Agricultural mechanization Guizhou Province
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Data-Driven Method for Predicting Remaining Useful Life of Bearings Based on Multi-Layer Perception Neural Network and Bidirectional Long Short-Term Memory Network
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作者 Yongfeng Tai Xingyu Yan +3 位作者 Xiangyi Geng Lin Mu Mingshun Jiang Faye Zhang 《Structural Durability & Health Monitoring》 2025年第2期365-383,共19页
The remaining useful life prediction of rolling bearing is vital in safety and reliability guarantee.In engineering scenarios,only a small amount of bearing performance degradation data can be obtained through acceler... The remaining useful life prediction of rolling bearing is vital in safety and reliability guarantee.In engineering scenarios,only a small amount of bearing performance degradation data can be obtained through accelerated life testing.In the absence of lifetime data,the hidden long-term correlation between performance degradation data is challenging to mine effectively,which is the main factor that restricts the prediction precision and engineering application of the residual life prediction method.To address this problem,a novel method based on the multi-layer perception neural network and bidirectional long short-term memory network is proposed.Firstly,a nonlinear health indicator(HI)calculation method based on kernel principal component analysis(KPCA)and exponential weighted moving average(EWMA)is designed.Then,using the raw vibration data and HI,a multi-layer perceptron(MLP)neural network is trained to further calculate the HI of the online bearing in real time.Furthermore,The bidirectional long short-term memory model(BiLSTM)optimized by particle swarm optimization(PSO)is used to mine the time series features of HI and predict the remaining service life.Performance verification experiments and comparative experiments are carried out on the XJTU-SY bearing open dataset.The research results indicate that this method has an excellent ability to predict future HI and remaining life. 展开更多
关键词 Remaining useful life prediction rolling bearing health indicator construction multilayer perceptron bidirectional long short-term memory network
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Research hotspot and trend of plant water use in karst: Based on a bibliometric analysis from 1984 to 2022
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作者 De-gen Zhu Jing Ning +5 位作者 Hui Yang Jun-bing Pu Jian-hua Cao Meng-xia Zhou Mitja Prelovsek Natasa Ravbar 《China Geology》 2025年第1期214-229,共16页
Research on the ecohydrological processes of terrestrial plants is a frontier field comprising ecology,hydrology and global change research,yielding the key theoretical foundations of ecohydrology.In karst areas,due t... Research on the ecohydrological processes of terrestrial plants is a frontier field comprising ecology,hydrology and global change research,yielding the key theoretical foundations of ecohydrology.In karst areas,due to its unique geological background,the karst landscape is strongly developed,with high bedrock exposure,high permeability,fragmented soils,shallow soils,and high spatial heterogeneity,resulting in very limited water storage for plant uptake and growth in rock fissures and shallow soils.Therefore,water conditions are an important ecological factor influencing plant growth.To comprehensively understand the current progress and development trends in plant water use research focusing on karst areas,this paper uses the VOSviewer software to analyze the literature on plant water use in karst areas between 1984 and 2022.The results showed that:(1)Research on plant water use in karst areas has developed rapidly worldwide,and the number of relevant studies in the literature have increased year by year,which together means that it is attracting more and more attention.(2)The investigation of plant water sources,geological background of karst areas,seasonal arid tropical climates,the relationship betweenδ13C values and plant water use efficiency,karst plant water use in karst savannas and subtropical areas,and ecosystems under climate change yields the knowledge base in this field.(3)Most studies in this area focus on the division of water sources of plants in karst areas,the methods of studying the water use sources of plants,and the water use strategies and efficiency of plants.(4)Future research will focus on how plant water use in karst areas is influenced by Earth’s critical zones,climate change,and ecohydrological separation.These studies will provide a key scientific basis for guiding ecological restoration and promoting sustainable development in karst areas. 展开更多
关键词 Terrestrial plants Plant water use Karst area Climate change ECOHYDROLOGY BIBLIOMETRICS Ecological restoration Sustainable development Environmental restoration engineering Web of Science
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Light Use Efficiency Model Based on Chlorophyll Content Better Captures Seasonal Gross Primary Production Dynamics of Deciduous Broadleaf Forests
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作者 YANG Rongjuan LIU Ronggao +3 位作者 LIU Yang CHEN Jingming XU Mingzhu HE Jiaying 《Chinese Geographical Science》 2025年第1期55-72,共18页
Gross primary production(GPP)is a crucial indicator representing the absorption of atmospheric CO_(2) by vegetation.At present,the estimation of GPP by remote sensing is mainly based on leaf-related vegetation indexes... Gross primary production(GPP)is a crucial indicator representing the absorption of atmospheric CO_(2) by vegetation.At present,the estimation of GPP by remote sensing is mainly based on leaf-related vegetation indexes and leaf-related biophysical para-meter leaf area index(LAI),which are not completely synchronized in seasonality with GPP.In this study,we proposed chlorophyll content-based light use efficiency model(CC-LUE)to improve GPP estimates,as chlorophyll is the direct site of photosynthesis,and only the light absorbed by chlorophyll is used in the photosynthetic process.The CC-LUE model is constructed by establishing a linear correlation between satellite-derived canopy chlorophyll content(Chlcanopy)and FPAR.This method was calibrated and validated utiliz-ing 7-d averaged in-situ GPP data from 14 eddy covariance flux towers covering deciduous broadleaf forest ecosystems across five dif-ferent climate zones.Results showed a relatively robust seasonal consistency between Chlcanopy with GPP in deciduous broadleaf forests under different climatic conditions.The CC-LUE model explained 88% of the in-situ GPP seasonality for all validation site-year and 56.0% of in-situ GPP variations through the growing season,outperforming the three widely used LUE models(MODIS-GPP algorithm,Vegetation Photosynthesis Model(VPM),and the eddy covariance-light use efficiency model(EC-LUE)).Additionally,the CC-LUE model(RMSE=0.50 g C/(m^(2)·d))significantly improved the underestimation of GPP during the growing season in semi-arid region,re-markably decreasing the root mean square error of averaged growing season GPP simulation and in-situ GPP by 75.4%,73.4%,and 37.5%,compared with MOD17(RMSE=2.03 g C/(m^(2)·d)),VPM(RMSE=1.88 g C/(m^(2)·d)),and EC-LUE(RMSE=0.80 g C/(m^(2)·d))model.The chlorophyll-based method proved superior in capturing the seasonal variations of GPP in forest ecosystems,thereby provid-ing the possibility of a more precise depiction of forest seasonal carbon uptake. 展开更多
关键词 canopy chlorophyll content(Chlcanopy) photosynthesis gross primary production(GPP) light use efficiency(LUE)model seasonal dynamics deciduous broadleaf forest(DBF)
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Land use/cover change and ecological network in Gansu Province,China during 2000-2020 and their simulations in 2050
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作者 MA Xinshu XIN Cunlin +6 位作者 CHEN Ning XIN Shunjie CHEN Hongxiang ZHANG Bo KANG Ligang WANG Yu JIAO Jirong 《Journal of Arid Land》 2025年第1期43-57,共15页
Land use/cover change(LUCC)constitutes the spatial and temporal patterns of ecological security,and the construction of ecological networks is an effective way to ensure ecological security.Exploring the spatial and t... Land use/cover change(LUCC)constitutes the spatial and temporal patterns of ecological security,and the construction of ecological networks is an effective way to ensure ecological security.Exploring the spatial and temporal change characteristics of ecological network and analyzing the integrated relationship between LUCC and ecological security are crucial for ensuring regional ecological security.Gansu is one of the provinces with fragile ecological environment in China,and rapid changes in land use patterns in recent decades have threatened ecological security.Therefore,taking Gansu Province as the study area,this study simulated its land use pattern in 2050 using patch-generating land use simulation(PLUS)model based on the LUCC trend from 2000 to 2020 and integrated the LUCC into morphological spatial pattern analysis(MSPA)to identify ecological sources and extract the ecological corridors to construct ecological network using circuit theory.The results revealed that,according to the prediction results in 2050,the areas of cultivated land,forest land,grassland,water body,construction land,and unused land would be 63,447.52,39,510.80,148,115.18,4605.21,8368.89,and 161,752.40 km^(2),respectively.The number of ecological sources in Gansu Province would increase to 80,with a total area of 99,927.18 km^(2).The number of ecological corridors would increase to 191,with an estimated total length of 6120.66 km.Both ecological sources and ecological corridors showed a sparse distribution in the northwest and dense distribution in the southeast of the province at the spatial scale.The number of ecological pinch points would reach 312 and the total area would expect to increase to 842.84 km^(2),with the most pronounced increase in the Longdong region.Compared with 2020,the number and area of ecological barriers in 2050 would decrease significantly by 63 and 370.71 km^(2),respectively.In general,based on the prediction results,the connectivity of ecological network of Gansu Province would increase in 2050.To achieve the predicted ecological network in 2050,emphasis should be placed on the protection of cultivated land and ecological land,the establishment of ecological sources in desert areas,the reinforcement of the protection for existing ecological sources,and the construction of ecological corridors to enhance the stability of ecological network.This study provides valuable theoretical support and references for the future construction of ecological networks and regional land resource management decision-making. 展开更多
关键词 patch-generating land use simulation(PLUS)model morphological spatial pattern analysis(MSPA) circuit theory ecological source ecological resistance surface ecological corridor ecological pinch point
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Study on Rational Fertilization Scheme for Mulberry(Morus alba Linn) Used for Tea 被引量:1
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作者 殷浩 王丽 +4 位作者 佟万红 黄盖群 危玲 郑继川 刘刚 《Agricultural Science & Technology》 CAS 2016年第11期2546-2550,2559,共6页
[Objective] This study was conducted to investigate effects of application amounts of N, P and K and their ratio on tea quality components in mulberry leaves. [Method] Effects of sole application and combined applicat... [Objective] This study was conducted to investigate effects of application amounts of N, P and K and their ratio on tea quality components in mulberry leaves. [Method] Effects of sole application and combined application of N, P and K on the yield and tea quality components of spring mulberry leaves were studied by 3-factor 3-level experiment, based on previous experiments. [Result] Combined ap- plication of 3 of N, P and K was better than sole application and combined appli- cation of 2 from them. Insufficient or excessive fertilization both significantly reduced yield of mulberry leaves and contents of tea quality components, such as 1-de- oxynojimycin (DNJ), flavonoids, tea polyphenols and amino acids. With the yield of spring mulberry leaves as a target, it is advised to apply N, P and K at rates of 240, 150 and 60 kg/hm^2 , respectively. [Conclusion] This study provides reference and theoretical basis for the establishment of raw material base of high-quality mul- berry tea. 展开更多
关键词 NPK Mulberry used for tea YIELD Tea quality
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Effects of Used Battery on Key Enzyme Activity during the Germination of Wheat Seeds
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作者 张恒 许兆棠 +2 位作者 李帅庆 韩玉良 陈智 《Agricultural Science & Technology》 CAS 2013年第1期135-137,143,共4页
[Objective] This study aimed to explore the effects of used battery lixivium on wheat germination. [Method] The wheat seeds were treated with used battery lix- ivium at different concentrations to detect the change of... [Objective] This study aimed to explore the effects of used battery lixivium on wheat germination. [Method] The wheat seeds were treated with used battery lix- ivium at different concentrations to detect the change of activities of amylase, pro- tease, pyruvate dehydrogenase (PDH) and polyphenol oxidase (PPO) during the ger- mination period. [Result] The results showed that the used battery affected enzyme activity. With the increase of concentration of used battery lixivium, trends of the changes of amylase and protease activities were not different. The activities were en- hanced at low concentrations of lixivium, while were inhibited at high concentrations. The tends of changes of pyruvate dehydrogenase (PDH) and polyphenol oxidase (PPO) activities were not consistent with that of either amylase or protease, which showed continuous downward trends with the increasing concentration of used battery lixivium. [Conclusion] This study is of great practical significance for understanding the effects of used battery lixivium on the germination of wheat seeds. 展开更多
关键词 used battery lixivium Germination of wheat seeds Activities of amylase protease pyruvate dehydrogenase(PDH) and polyphenol oxidase(PPO)
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would和used to表示“过去常常”用法小议
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作者 鲁红霞 《中小学英语教学与研究》 2005年第6期62-62,共1页
would表示过去的习惯、习性、倾向等,相当于used to(过去常常)。例如:
关键词 WOULD used to” 用法 中学 英语
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would与used to
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作者 蒋建平 《中学英语园地(高三版)》 2002年第5期17-18,共2页
would与used to都可用来表示过去经常发生的动作,常常可以互相换用。例如:
关键词 WOULD used to” 高中 英语 词语辨析
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Used一词的用法辨析
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作者 冉明志 《攀枝花学院学报》 2003年第3期56-56,共1页
关键词 used 英语词汇 用法 语法 不及物动词 过去分词
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There used to…的反意疑问部分是什么?
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作者 常建清 《英语知识》 2003年第12期42-42,共1页
[问][415]《全国成人高考统考全真模拟试卷英语》(新世界出版社p.56)有一道试题: There used to be a coffer shop next to your house,______? A.wasn’t there B.didn’t there C.wasn’t it D.didn't it 答案为A。请问这个答案对... [问][415]《全国成人高考统考全真模拟试卷英语》(新世界出版社p.56)有一道试题: There used to be a coffer shop next to your house,______? A.wasn’t there B.didn’t there C.wasn’t it D.didn't it 答案为A。请问这个答案对吗? [答]《牛津高阶英汉双解词典》指出。 展开更多
关键词 “There used to…” 成人高考 全国统一考试 英语 模拟试题 选择题 反意疑问句 用法 试题分析
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Dry reusing and wet reclaiming of used sodium silicate sand 被引量:4
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作者 Zitian FAN Naiyu HUANG +1 位作者 Huafang WANG Xuanpu DONG 《China Foundry》 SCIE CAS 2005年第1期38-43,共6页
Based on the characteristics of used sodium silicate sand and the different use requirements for recycled sand, "dry reusing and wet reclaiming of used sodium silicate sand" is considered as the most suitabl... Based on the characteristics of used sodium silicate sand and the different use requirements for recycled sand, "dry reusing and wet reclaiming of used sodium silicate sand" is considered as the most suitable technique for the used sand. When the recycled sand is used as support sand, the used sand is only reused by dry process including breaking, screening, dust-removal, etc., and it is not necessary that the used sand is reclaimed with strongly rubbing and scraping method, but when the recycled sand is used as facing sand (or single sand), the used sand must be reclaimed by wet method for higher removal rate of the residual binders. The characteristics and the properties of the dry reused sand are compared with the wet reclaimed sand after combining the different use requirements of support sand and facing sand (or single sand), and above the most adaptive scheme has also been validated. 展开更多
关键词 used SODIUM SILICATE SAND DRY reusing WET reclaiming
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Design,delivery and efficacy testing of therapeutic nucleic acids used to inhibit hepatitis C virus gene expression in vitro and in vivo 被引量:9
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作者 Wolfgang H.Caselmann Matthias Serwe +3 位作者 Thomas Lehmann János Ludwig Brian S.Sproat Joachim W.Engels 《World Journal of Gastroenterology》 SCIE CAS CSCD 2000年第5期626-629,共4页
Despite major achievements in the treatment ofchronic hepatitis C with the combination ofinterferons and the nucleoside analog ribavirin themajority of patients with chronic hepatitis C virus(HCV) infection cannot be ... Despite major achievements in the treatment ofchronic hepatitis C with the combination ofinterferons and the nucleoside analog ribavirin themajority of patients with chronic hepatitis C virus(HCV) infection cannot be treated effectively.Toimprove this response rate we used antisensetechnologies to inhibit HCV translation as possibleadditional option for experimental treatment.Antisense oligodeoxynucleotides(ODN) are 展开更多
关键词 hepatitis C-like viruses/therapy gene expression in VITRO in vivo nucleic acids/therapeutic use CYTOMEGALOVIRUS
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CELLULOSE MEMBRANE USED AS STATIONARY PHASE OF MEMBRANE AFFINITY CHROMATOGRAPHY 被引量:2
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作者 Wei GUO Zhen Hua SHANG Yi Nian YU and Liang Mo ZHOU (Dalian Institute of Chemical Physics, Chinese, Academy of Sciences P.O. Box 100, Datian 116012) 《Chinese Chemical Letters》 SCIE CAS CSCD 1994年第10期869-872,共4页
Cellulose membrane was used as Stahonary phase Of affinity chromeqraphy. A  ̄ for theprepeboon Of microPOre cellulose membone born cellulose balm is describ6d. Terne dyeS,Cibacron BIne F3GA and cave Red KZBP were immo... Cellulose membrane was used as Stahonary phase Of affinity chromeqraphy. A  ̄ for theprepeboon Of microPOre cellulose membone born cellulose balm is describ6d. Terne dyeS,Cibacron BIne F3GA and cave Red KZBP were immobilbe as amnty figeds. UP tO IO0 mgCibacron BIne F3G^ can be coupled ontO 1 g merebrane mainx. A membene cadridge cocainingblue affinty membranes was also Prepared. The flux of the cadridge was much superior to that Ofcolumn PaCked ed agarose as sepadsn odium. On this cable, the Chromatography ofhuman seam albumin was performed. 展开更多
关键词 AS STATIONARY used MEMBRANE OF AFFINITY CELLULOSE
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Feature of flow stress of aluminum sheet used for can during hot compression 被引量:4
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作者 傅高升 钱匡武 +1 位作者 陈文哲 康积行 《中国有色金属学会会刊:英文版》 CSCD 2000年第5期671-674,共4页
The flow stress feature of aluminum sheet used for pressure can during plastic deformation at elevated temperature was studied by isothermal compression test using Gleeble 1 500 dynamic materials testing machine. The ... The flow stress feature of aluminum sheet used for pressure can during plastic deformation at elevated temperature was studied by isothermal compression test using Gleeble 1 500 dynamic materials testing machine. The experimental results show that the steady state deformation is remarkable when the material is deformed in the temperature range of 350~500 ℃ at strain rates within the range of 10 -2 ~10.0 s -1 . The material is sensitive to positive strain rate. A hyperbolic sine relationship is found to correlate well the flow stress with the strain rate, and an Arrhenius relationship with the temperature. Semi empirical constitutive equations of the flow stress are derived from all experimental data for tested material during plastic deformation at elevated temperature by polyelement linear regression analysis. [ 展开更多
关键词 aluminum SHEET used for CAN high temperature PLASTIC deformation compression flow stress
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Wet reclamation of sodium silicate used sand and biological treatment of its wastewater by Nitzschia palea 被引量:5
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作者 Wang Huafang Fan Zitian +2 位作者 Yu Shaoqiang Liu Fuchu Li Xuejie 《China Foundry》 SCIE CAS 2012年第1期34-38,共5页
The massive amount of sodium silicate in the used sand was a pollution source, especially in the waste water from the wet reclamation of used sand. A new process of wet reclamation by biologically treating the waste w... The massive amount of sodium silicate in the used sand was a pollution source, especially in the waste water from the wet reclamation of used sand. A new process of wet reclamation by biologically treating the waste water produced during the wet reclamation process of used sand was studied in the paper. In the work, the precultivation of N. palea was performed firstly, and three different scrubbing solutions: (1) tap water, (2) modified medium for N. palea, and (3) filtrate of the broth treated by N. palea for 15 days, were used. The results of the primary investigation show that a de-skinning ratio of 90% is obtained when using the scrubbing solution containing modified medium for N. palea at the ratio 1:2 of sand and scrubbing solution, and the maximal concentrations of Na^+ and SiO3^2- are 1.49 g.L-1 and 0.51 g.L-1, respectively. The results of the optimal biomass, pH value decrease and Na^+ and SiO32 consumption indicate the optimal incubation conditions are at the irradiance of 5,000 lux and 25 ℃. Using the filtrate of the broth treated by N. palea for 15 days as the scrubbing solution directly, a de-skinning ratio of 93% is the highest compared to the results of the tap water and the modified medium for N. palea. In the biological process using N. palea, less water is used and little wastewater is produced, which is advantageous to the purpose of green manufacturing and environmental protection. 展开更多
关键词 sodium silicate used sand biological reclamation method N.palea
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