检索结果-南通市图书馆

Recovery of yttrium from deep-sea mud

Journal of Rare Earths 2018年第8期36卷 863-872页

作者： Kuifang Zhang Zhiqiang Liu Changyong Sun Hongyang Cao Kechao Zhu Wei Zhu Wei Li Guangdong Province Key Laboratory of Rare Earth development and Application Guangdong Province Research Institute of Rare Metals Cuangzhou 510650 China Guangzhou Marine Geological Survey Guangzhou 510075 China

Deep-sea mud rich in rare earth yttrium has received lots of attention from the international community as a new resource for Y. A novel process, which mainly includes acid leaching, solvent extraction, and oxalic acid precipitation-roasting, is proposed for recovery of Y from deep-sea mud. A series of experiments were conducted to inspect the impacts of various factors during the process and the optimum conditions were determined. The results show that the Y of deep-sea mud totally exists in apatite minerals which can be decomposed by hydrochloric acid and sulfuric acid solution. The highest leaching efficiency of Y is 94.53% using hydrochloric acid and 84.38% using sulfuric acid under the conditions of H^＋concentration 2.0 mol/L, leaching time 60 min, liquid-solid ratio 4：1 and room temperature 25 ℃（only in case of sulfuric acid, when using hydrochloric acid, the leaching temperature should be 60 ℃）. Because of the much lower leaching temperature, sulfuric acid leaching is preferred. The counter current extraction and stripping tests were simulated by a cascade centrifugal extraction tank device. Using 10 vol% P204,15 vol% TBP and 75 vol% sulfonated kerosene as extractant, 98.79% Y^3＋ and 42.60% Fe^3＋ are extracted from sulfuric acid leaching liquor（adjusted to pH = 2.0） after seven-stage counter current extraction with O/A ratio of 1：1 at room temperature, while other metals ions such as Al^3＋, Ca^2＋, Mg^2＋and Mn^2＋ are almost not extracted. The Y^3＋ in loaded organic can be selectively stripped using 50 g/L sulfuric acid solution and the stripping efficiency reaches 99.86% after seven-stage counter current stripping with O/A ratio of 10：1 at room temperature, while only 2.26% co-extracted Fe^3＋ is stripped. The Y^3＋ of loaded strip liquor can be precipitated by oxalic acid to further separate Y^3＋ and Fe^3＋. The precipitation efficiency of Y^3＋ in loaded strip liquor can be 98.56% while Fe^3＋ is not precipitated under the conditions of oxalic acid solution conce

关键词： Yttrium Recovery Deep-sea mud Acid leaching Solvent extraction Oxalic acid precipitation-roasting

来源：

维普期刊数据库

同方期刊数据库评论

在线全文

学校读者我要写书评

暂无评论

Improvement of the prediction performance of a soft sensor model based on support vector regression for production of ultra-low sulfur diesel

引用

Petroleum Science 2015年第1期12卷 177-188页

作者： Saeid Shokri Mohammad Taghi Sadeghi Mahdi Ahmadi Marvast Shankar Narasimhan Department of Chemical Engineering Iran University of Science and Technology (IUST) Process and Equipment Technology development Division Research Institute of Petroleum Industry (RIPI) Department of Chemical Engineering

A novel data-driven, soft sensor based on support vector regression （SVR） integrated with a data compression technique was developed to predict the product quality for the hydrodesulfurization （HDS） process. A wide range of experimental data was taken from a HDS setup to train and test the SVR model. Hyper-parameter tuning is one of the main challenges to improve predictive accuracy of the SVR model. Therefore, a hybrid approach using a combination of genetic algorithm （GA） and sequential quadratic programming （SQP） methods （GA-SQP） was developed. Performance of different optimization algorithms including GA-SQP, GA, pattern search （PS）, and grid search （GS） indicated that the best average absolute relative error （AARE）, squared correlation coefficient （R2）, and computation time （CT）（AARE = 0.0745, R2 = 0.997 and CT = 56 s） was accomplished by the hybrid algorithm. Moreover, to reduce the CT and improve the accuracy of the SVR model, the vector quantization （VQ） technique was used. The results also showed that the VQ technique can decrease the training time and improve prediction performance of the SVR model. The proposed method can provide a robust, soft sensor in a wide range of sulfur contents with good accuracy.

关键词： Soft sensor Support vector regression Hybrid optimization method Vector quantization Petroleum refinery Hydrodesulfurization process Gas oil

来源：

维普期刊数据库

同方期刊数据库评论

在线全文

学校读者我要写书评

暂无评论

ACQ到CIE转化:水合作用诱导的姜黄素晶体发光及可调热致变色用于体内药物追踪（英文）

引用

Science China Materials 2024年第11期67卷 3561-3569页

作者：申欢石鹏刘二刚方月飞许史杰龚俊波黄永焯 Zhongshan Institute for Drug Discovery Shanghai Institute of Materia MedicaChinese Academy of Sciences Shanghai Institute of Materia Medica Chinese Academy of Sciences School of Chemical Engineering and Technology Tianjin University SINOPEC research Institute of Petroleum Processing Co. Ltd. College of Chemical Engineering and Materials Science Tianjin University of Science and Technology NMPA Key Laboratory for Quality research and Evaluation of Pharmaceutical Excipients

目前固态材料在受刺激时能够切换发光性质仍然是一个挑战,特别是对于有机材料而言.晶体中的水分子极大地影响有机晶体的吸收光谱,但是否可以系统地通过水分子调控有机发光材料的发射光谱尚不清楚.在本研究中,我们成功地制备了姜黄素一... 详细信息

目前固态材料在受刺激时能够切换发光性质仍然是一个挑战,特别是对于有机材料而言.晶体中的水分子极大地影响有机晶体的吸收光谱,但是否可以系统地通过水分子调控有机发光材料的发射光谱尚不清楚.在本研究中,我们成功地制备了姜黄素一水合物(X型),它是一种结晶诱导发光(CIE)的通道型水合物,在608 nm处发出橙色荧光,与传统的聚集诱导荧光猝灭(ACQ)形式有所不同.经过热处理后,姜黄素水合物释放出水分子,形成了新的无水合物(Ⅳ型),其发出黄绿色荧光,且最佳发射波长为575 nm.该方法可用于追踪皮下或肌肉注射后姜黄素晶体的吸收.水合物介导的单晶到单晶转变(SCSC)及其相关的发光转变是可逆的,并且对温度敏感,可为合成和设计基于聚集诱导发射(AIE)的智能发光装置提供一种环保的途径,也可用于检测空气湿度或示踪药物吸收.

关键词： curcumin crystallization-induced emission channel-type hydrate single-crystal-to-single-crystal transition reversible luminescence

来源：

同方期刊数据库评论

在线全文

同方期刊数据库

学校读者我要写书评

暂无评论

Evaluation and advancement of the integrated circular economy model of farming and stock raising

引用

Chinese Journal of Population,Resources and Environment 2020年第4期18卷 350-360页

作者： Qingsong Wang Mingqiang Liu Yuzhou Tang Xueliang Yuan Qiao Ma research Center for Sustainable development School of Energy and Power EngineeringShandong UniversityJinan250061China

The integrated circular economy model of farming and stock raising(ICEMFSR)has attracted increased attention as an effective model for solving the current irrational allocation of agricultural resources and realizing the agricultural value-added industrial *** study uses emergy analysis to comprehensively examine and evaluate the economic benefits,environmental pressures,and sustainable development levels of ICEMFSR in Shucheng County,*** results show that the ICEMFSR possesses the value of popularization with optimally allocated resources in the studied region,in which the emergy yield ratio(EYR),emergy loading ratio(ELR),and emergy sustainable index(ESI)in this model accounted for 3.59,1.25,and 2.89,*** result indicates a leading position in the national agricultural ***,this study constructs a new model based on the coupling of emergy evaluation and multi-objective linear programming to study ***,the EYR,ELR,and ESI respectively varied by +24.23%,10.40%,and +38.06%after replanning of *** variation implies a significant improvement in the sustainable development level of the *** addition,the optimized scenario design for key substances is proposed based on traceability and the reduce-reuse-recycle principle,including biogasification of crop straw and enhancement of crop scientific planting capacity.

关键词： Circular economy model Emergy evaluation Multi-objective linear programming Optimization suggestions

来源：

维普期刊数据库

同方期刊数据库评论

在线全文

学校读者我要写书评

暂无评论

Influence of hydrogen fugacity on thermal transformation of sedimentary organic matter:Implications for hydrocarbon generation in the ultra-depth

引用

Science China Earth Sciences 2022年第11期65卷 2188-2201页

作者： Jia WU Fujia JI Yuan WANG Bernhard M.KROOSS Kun HE Xiao JIN Qingyong LUO Yanan YANG Ningning ZHONG State Key Laboratory of Petroleum Resources and Prospecting China University of Petroleum(Beijing)Beijing 102249China College of Geoscience China University of Petroleum(Beijing)Beijing 102249China K&A Petrophysics Consulting Juelich 52428Germany PetroChina research Institute of Petroleum Exploration&development Beijing 100083China development and research Center National Geological Archives of ChinaChina Geological SurveyBeijing 100037China

Hydrocarbon generation from sedimentary organic matter(SOM)with an original net C oxidation state(OS,-1–-2)is a disproportionation reaction involving the transfer of internal(“organic”)hydrogen and producing oxidized C(up to OS=+4)and reduced C(down to OS=-4).The contribution of extrinsic(“inorganic”)hydrogen could lead to an increase of hydrocarbon yields,but mechanisms and potential sources are still unclear,although it is supported by some experimental *** this study,we have analyzed quantitatively the effect of increasing hydrogen fugacity on the hydrocarbon generation behavior of the Cambro-Ordovician Alum shale at 350℃and 40 *** fugacity in the experimental system was controlled by the magnetite-hematite(MH)*** experimental data confirm that a more reducing environment will increase overall hydrocarbon yields and depress CO_(2) *** elevated hydrogen fugacity was found to correlate with an increase in δ^(13)C isotopic composition of methane and a decrease of δ^(13)C values in CO_(2),ethane and *** demonstrates that elevated hydrogen fugacity constrained by water-rock reaction in sedimentary basins can enhance hydrocarbon generation by“hydrocracking”.This mechanism of hydrocarbon generation by organic-inorganic interactions might be ubiquitous in the deeper sections of sedimentary basins(approximately 4–10 km).Thus,it will extend the connotation of the current theory on petroleum *** level of hydrogen fugacity,constrained by water-rock reactions,increases with depth and may thus activate over-maturity sedimentary organic matter to produce more *** end of hydrocarbon generation will thus move to a greater depth than predicted by the traditional *** will be correlated to the capacity of the buffer system,which should,in consequence,be taken into account in petroleum exploration,similar to the hydrogen index(HI)of *** extension of the fundamental theory will help to enlarge the area of petro

关键词： Hydrous pyrolysis Thermal decomposition Magnetite-hematite redox buffer Hydrocarbon generation Organic-inorganic interaction

来源：

维普期刊数据库

同方期刊数据库评论

在线全文

学校读者我要写书评

暂无评论

Association between microRNA-21, microRNA-150, and micro- RNA-451 expression and clinical outcome of patients with acute lymphoblastic leukemia

引用

Frontiers in Biology 2017年第1期12卷 63-70页

作者： Ali Amin Asnafi Elahe Khodadi Neda Golchin Arash Alghasi Yousef Tavakolifar Najmaldin Saki Health research Institute Research Center of Thalassemia and Hemoglobinopathy Ahvaz Jundishapur University of Medical Sciences Ahvaz Iran Golestan hospital clinical research development unit Ahvaz Jundishapur University of Medical Sciences Ahvaz Iran

BACKGROUND： Acute lymphoblastic leukemia （ALL） occurs owing to the defective maturation, increased proliferation, and lack of differentiation of lymphoid cells. Evaluation of the expression levels of microRNAs （miRNAs） could help in the prognosis and improve the clinical outcome of ALL patients. Given the role of miR-21, miR-150, and miR-451 as oncogenes and tumor suppressors in lymphocytes, this study explored the relation between the expression levels of these miRNAs and the clinical outcomes of ALL patients. METHODS： cDNA synthesis and RT-PCR were performed for peripheral blood samples from 41 patients with ALL, as well as for U937 and Jurkat cell lines to examine the expression of miR-451, miR-150, and miR-21 after miRNA purification. We also performed an epidemiological analysis in which Mann-Whitney and Chi-square tests were used to investigate the relationship between the expression of miRNAs and other clinical and laboratory data. Binary logistic regression models were used to estimate the odds ratio in univariate and multivariate analyses for clinical outcomes. RESULTS： miR-21 and miR-150 expression was found to be decreased, while miR-451 expression showed no difference compared to the control group. There was a significant relationship between miR-451 expression and hemoglobin （Hb） levels, as well as between miR-150 expression and clinical outcomes of ALL patients. CONCLUSION： Increased expression of miR-451 decreased the Hb levels; reduced expression of miR-150 was associated with increased relapse rate in patients. Age, increased WBC, and decreased Hb levels were associated with increased relapse rates in ALL patients. Therefore, miR-150 could be used as a biomarker to determine the clinical outcome of ALL patients.

关键词： acute lymphoblastic leukemia miRNA clinical outcome

来源：

维普期刊数据库评论

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

Health implication among occupational exposed workers in a chromium alloy factory, Thailand

引用

Journal of Environmental Sciences 2004年第2期16卷 181-186页

作者： S. Muttamara Shing Tet Leong research Lab Supervisor Urban Environmental Engineering and Management Program School of EnvironmentResources and DevelopmentAsian Institute of Technology G.P.O. Box 4Klong LuangResearch Lab SupervisorUrban Environmental Engineering and Management Program School of EnvironmentResources and DevelopmentAsian Institute of Technology G.P.O. Box 4Klong Luang Pathumthani 12120 ThailandPathumthani 12120 Thailand

This study was conducted to assess the occupational exposure and its health impact on the chromium alloy workers. Environmental and biological monitoring, noise and audiometry measurements were done to evaluate the exposure levels in the factory. A total of 112 non-smoking workers were monitored from July 2001 to August 2002 The results showed that most of the chromium and lead exposures in the factory were below the ACGIH-TWA of 50 μg/m 3 for chromium(Ⅵ) and OSHA-PEL of 50 μg/m 3 for lead. The highest chromium(7 25±0 16 μg/m 3) and lead(14 50±0 29 μg/m 3) concentrations were measured in the vibro room. The results indicated that elevated concentrations of chromium and lead were found in both blood and urine samples especially in those areas which were characterized by poor ventilation. The metal contents in blood and urine samples were significantly correlated with airborne metal concentrations in the factory. The result demonstrated that blood and urinary levels among workers were associated with increasing age and duration of exposure. The background noise level of the factory ranged from 67 6 to 89 2 dBA and was frequently higher than the threshold limit value for noise(90 dBA). According to the audiometric test, the exposed workers showed signs of noise-induced hearing loss. Noise at work continued to be an important factor to hearing loss among exposed workers. In our statistical analysis, a significant hearing loss was established on age effect and year of exposure among the workforce.

关键词： chromium and lead exposure electroplating environmental and biological monitoring audiometry measurement

来源：

维普期刊数据库

同方期刊数据库评论

在线全文

学校读者我要写书评

暂无评论

Preparation and characterization of ceramic materials with low thermal conductivity and high strength using high-calcium fly ash

引用

International Journal of Minerals,Metallurgy and Materials 2022年第8期29卷 1635-1645页

作者： Mana Rodchom Panida Wimuktiwan Kanit Soongprasit Duangduen Atong Supawan Vichaphund Ceramics and Construction Materials research Group National Metal and Materials Technology Center(MTEC)National Science and Technology Development Agency(NSTDA)Khlong NuengKhlong LuangPathumthani 12120Thailand

High calcium-fly ash(HCFA)collected from the Mae Moh electricity generating plant in Thailand was utilized as a raw material for ceramic *** main compositions of HCFA characterized by X-ray fluorescence mainly consisted of 28.55wt%SiO_(2),16.06wt%Al_(2)O_(3),23.40wt%CaO,and 17.03wt%Fe_(2)O_(3).Due to high proportion of calcareous and ferruginous contents,HCFA was used for replacing the potash feldspar in amounts of 10wt%-40wt%.The influence of substituting high-calcium fly ash(0-40wt%)and sintering temperatures(1000-1200℃)on physical,mechanical,and thermal properties of ceramic-based materials was *** results showed that the in-corporation of HCFA in appropriate amounts could enhance the densification and the strength as well as reduce the thermal conductivity of ceramic *** proportion of calcareous and ferruginous constituents in fly ash promoted the vitrification behavior of ceramic *** a result,the densification was enhanced by liquid phase formation at optimum fly ash content and sintering *** addition,these components also facilitated a more abundant mullite formation and consequently improved flexural strength of the ceramic *** op-timum ceramic properties were achieved with adding fly ash content between 10wt%-30wt%sintered at 1150-1200℃.At 1200℃,the max-imum flexural strength of ceramic-FA samples with adding fly ash 10wt%-30wt%(PSW-FA(10)-(30))was obtained in the range of 92.25-94.71 MPa when the water absorption reached almost zero(0.03%).In terms of thermal insulation materials,the increase in fly ash addi-tion had a positively effect on the thermal conductivity,due to the higher levels of porosity created by gas evolving from the inorganic decom-position reactions inside the ceramic-FA *** addition of 20wt%-40wt%high-calcium fly ash in ceramic samples sintered at 1150℃reduced the thermal conductivity to 14.78%-49.25%,while maintaining acceptable flexural strength values(~45.67-87.62 MPa).

关键词： ceramic materials high-calcium fly ash strength thermal conductivity

来源：

维普期刊数据库

同方期刊数据库评论

在线全文

学校读者我要写书评

暂无评论

Cone-beam computed tomography noise reduction method based on U-Net with convolutional block attention module in proton therapy

引用

Nuclear Science and Techniques 2024年第7期35卷 89-100页

作者： Xing-Yue Ruan Xiu-Fang Li Meng-Ya Guo Mei Chen Ming Lv Rui Li Zhi-Ling Chen Shanghai Institute of Applied Physics Chinese Academy of SciencesShanghai201800China University of Chinese Academy of Sciences Beijing100049China Shanghai Advanced research Institute Chinese Academy of SciencesShanghai201210China Department of Radiation Oncology Ruijin HospitalShanghai Jiao Tong University School of MedicineShanghai200025China Shanghai Key Laboratory of Proton therapy Shanghai201801China

Cone-beam computed tomography(CBCT) is mostly used for position verification during the treatment process. However,severe image artifacts in CBCT hinder its direct use in dose calculation and adaptive radiation therapy re-planning for proton therapy. In this study, an improved U-Net neural network named CBAM-U-Net was proposed for CBCT noise reduction in proton therapy, which is a CBCT denoised U-Net network with convolutional block attention modules. The datasets contained 20 groups of head and neck images. The CT images were registered to CBCT images as ground truth. The original CBCT denoised U-Net network, sCTU-Net, was trained for model performance comparison. The synthetic CT(SCT) images generated by CBAM-U-Net and the original sCTU-Net are called CBAM-SCT and U-Net-SCT images, respectively. The HU accuracies of the CT, CBCT, and SCT images were compared using four metrics: mean absolute error(MAE), root mean square error(RMSE), peak signal-to-noise ratio(PSNR), and structure similarity index measure(SSIM). The mean values of the MAE, RMSE, PSNR, and SSIM of CBAM-SCT images were 23.80 HU, 64.63 HU, 52.27 dB, and 0.9919, respectively,which were superior to those of the U-Net-SCT images. To evaluate dosimetric accuracy, the range accuracy was compared for a single-energy proton beam. The γ-index pass rates of a 4 cm × 4 cm scanned field and simple plan were calculated to compare the effects of the noise reduction capabilities of the original U-Net and CBAM-U-Net on the dose calculation results. CBAM-U-Net reduced noise more effectively than sCTU-Net, particularly in high-density tissues. We proposed a CBAM-U-Net model for CBCT noise reduction in proton therapy. Owing to the excellent noise reduction capabilities of CBAM-U-Net, the proposed model provided relatively explicit information regarding patient tissues. Moreover, it maybe be used in dose calculation and adaptive treatment planning in the future.

关键词： Proton therapy Cone-beam CT CBAM-U-Net γ-index

来源：

维普期刊数据库

同方期刊数据库评论

在线全文

学校读者我要写书评

暂无评论

Evolution and influencing factors of the transnational investment network of China–Africa international cooperation parks

引用

Journal of Geographical Sciences 2022年第11期32卷 2205-2228页

作者： ZHAO Shengbo WANG Xingping LI Kailun LI Yingcheng School of Architecture Southeast UniversityNanjing 210096China Center for International Collaboration and research on development and Planning of Sustainable Industrial Parks Southeast UniversityNanjing 210096China

Based on development data relating to China–Africa International Cooperation Parks(CAICPs)from 2003 to 2018,this study examined the transnational investment network of CAICPs using the social network analysis *** number of CAICPs is *** and apparel,agricultural and food processing,trade logistics and management,building materials and construction,and electrical machinery and equipment manufacturing are the leading industries chosen by most *** parks have promoted the economic and social development of African countries,driving the urbanization of the regions in which the parks are located,and they have also benefited *** network of CAICPs involves China,African countries,and third-party *** network is becoming increasingly complex and has an increasingly high ***,the key node countries and provincial units remain relatively stable despite changes in the network *** center of gravity of the network has shown noticeable deviations and regression,and inter-provincial investment cooperation has also been ***–Africa cooperation drives the evolution of the *** China,the investment of enterprises in Africa is affected by domestic policy,economic pursuit,and investment *** Africa,the development of CAICPs is driven by development policies and achievements,and it is influenced by African countries’business environments.

关键词： China Africa industrial park investment network

来源：

维普期刊数据库

同方期刊数据库评论

在线全文

学校读者我要写书评

暂无评论

欢迎您,

建议与咨询留下您的常用邮箱和电话号码，以便我们向您反馈解决方案和替代方法

时间限定

文献类型

馆藏选择

核心期刊

语言

文献类型

帮助

文字说明：

检索规则说明：

检索范例：

分类表

所选分类

限定检索结果

文献类型

馆藏范围

日期分布

学科分类号

主题

机构

作者

语言

在线全文

在线全文

在线全文

在线全文

在线全文

在线全文

在线全文

在线全文

在线全文

在线全文

请选择保存的检索档案：

请选择收藏分类：

通借通还

欢迎您,

建议与咨询 留下您的常用邮箱和电话号码，以便我们向您反馈解决方案和替代方法

时间限定

文献类型

馆藏选择

核心期刊

语言

文献类型

帮助

文字说明：

检索规则说明：

检索范例：

分类表

所选分类

限定检索结果

文献类型

馆藏范围

日期分布

学科分类号

主题

机构

作者

语言

在线全文

在线全文

在线全文

在线全文

在线全文

在线全文

在线全文

在线全文

在线全文

在线全文

请选择保存的检索档案： 新增检索档案 确定 取消

请选择收藏分类： 新增自定义分类 确定 取消

通借通还

建议与咨询留下您的常用邮箱和电话号码，以便我们向您反馈解决方案和替代方法

请选择保存的检索档案：

请选择收藏分类：