检索结果-南通市图书馆

Chemical modification of barite for improving the performance of weighting materials for water-based drilling fluids

引用

Petroleum Science 2024年第1期21卷 551-566页

作者： Li-Li Yang Ze-Yu Liu shi-bo Wang Xian-Bo he guan-Cheng Jiang Jie Zhang MOE Key Laboratory of Petroleum Engineering State Key Laboratory of Petroleum Resources and ProspectingChina University of Petroleum(Beijing)Changping DistrictBeijing102249China MOE Key CNPC Drilling Research Institute Changping DistrictBeijing102206China

With increasing drilling depth and large dosage of weighting materials,drilling fluids with high solid content are characterized by poor stability,high viscosity,large water loss,and thick mud cake,easier leading to reservoir damage and wellbore instability.In this paper,micronized barite(MB)was modified(mMB)by grafting with hydrophilic polymer onto the surface through the free radical polymerization to displace conventional API barite partly.The suspension stability of water-based drilling fluids(WBDFs)weighted with API barite:mMB=2:1 in 600 g was significantly enhanced compared with that with API barite/WBDFs,exhibiting the static sag factor within 0.54 and the whole stability index of 2.The viscosity and yield point reached the minimum,with a reduction of more than 40%compared with API barite only at the same density.Through multi-stage filling and dense accumulation of weighting materials and clays,filtration loss was decreased,mud cake quality was improved,and simultaneously it had great reservoir protection performance,and the permeability recovery rate reached 87%.In addition,it also effectively improved the lubricity of WBDFs.The sticking coefficient of mud cake was reduced by 53.4%,and the friction coefficient was 0.2603.Therefore,mMB can serve as a versatile additive to control the density,rheology,filtration,and stability of WBDFs weighted with API barite,thus regulating comprehensive performance and achieving reservoir protection capacity.This work opened up a new path for the productive drilling of extremely deep and intricate wells by providing an efficient method for managing the performance of high-density WBDFs.

关键词： Drilling fluids Weighting materials Filtration control Reservoir protection Stability property

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

Review on synergistic damage effect of irradiation and corrosion on reactor structural alloys

引用

Nuclear Science and Techniques 2024年第3期35卷 109-141页

作者： Hui Liu guan-Hong Lei he-Fei Huang Shanghai Institute of Applied Physics Chinese Academy of SciencesShanghai 201800China School of Nuclear Science and Technology University of Chinese Academy of SciencesBeijing 100049China

The synergistic damage effect of irradiation and corrosion of reactor structural materials has been a prominent research focus.This paper provides a comprehensive review of the synergistic effects on the third-and fourth-generation fission nuclear energy structural materials used in pressurized water reactors and molten salt reactors.The competitive mechanisms of multiple influencing factors,such as the irradiation dose,corrosion type,and environmental temperature,are summarized in this paper.Conceptual approaches are proposed to alleviate the synergistic damage caused by irradiation and corrosion,thereby promoting in-depth research in the future and solving this key challenge for the structural materials used in reactors.

关键词： Irradiation and corrosion Synergistic effect Austenitic stainless steels Nickel-based alloys Reactors

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

Circulating RNA ZFR promotes hepatocellular carcinoma cell proliferation and epithelial-mesenchymal transition process through miR-624-3p/WEE1 axis

引用

hepatobiliary & Pancreatic Diseases International 2024年第1期23卷 52-63页

作者： Li Zhang Sai he Hao guan Yao Zhao Di Zhang Department of General Surgery the Second Affiliated Hospital of Xi’an Jiaotong UniversityXi’an 710004China Department of Breast Cancer Shaanxi Provincial Cancer HospitalXi’an 710000China

Background:hepatocellular carcinoma(HCC),the most common type of primary liver cancer,is the fourth leading cause of cancer-related deaths worldwide.Previous evidence shows that the expression of circulating RNA ZFR(circZFR)is upregulated in HCC tissues.However,the molecular mechanism of circZFR in HCC is unclear.Methods:Quantitative reverse transcriptase polymerase chain reaction(qRT-PCR)was employed to detect the expression of circZFR,microRNA-624-3p(miR-624-3p)and WEE1 in HCC tissues and cells.RNase R assay and actinomycin D treatment assay were used to analyze the characteristics of circZFR.For functional analysis,the capacities of colony formation,cell proliferation,cell apoptosis,migration and invasion were assessed by colony formation assay,5-ethynyl-2-deoxyuridine(EdU)assay,flow cytometry assay and transwell assay.Western blot was used to examine the protein levels of WEE1 and epithelial-mesenchymal transition(EMT)-related proteins.The interactions between miR-624-3p and circZFR or WEE1 were validated by dual-luciferase reporter assay and RNA immunoprecipitation(RIP)assay.Xenograft models were established to determine the role of circZFR in vivo.Results:circZFR and WEE1 were upregulated,while miR-624-3p expression was reduced in HCC tissues and cells.circZFR could sponge miR-624-3p,and WEE1 was a downstream gene of miR-624-3p.Knockdown of circZFR significantly reduced the malignant behaviors of HCC and that co-transfection with miR624-3p inhibitor restored this change.Overexpression of WEE1 abolished the inhibitory effect of miR624-3p mimic on HCC cells.Mechanistically,circZFR acted as a competitive endogenous RNA(ceRNA)to regulate WEE1 expression by targeting miR-624-3p.Furthermore,in vivo studies have illustrated that circZFR knockdown inhibited tumor growth.Conclusions:circZFR knockdown reduced HCC cell proliferation,migration and invasion and promoted apoptosis by regulating the miR-624-3p/WEE1 axis,suggesting that the circZFR/miR-624-3p/WEE1 axis might be a potential target for HCC treatment.

关键词： hepatocellular carcinoma circZFR miR-624-3p WEE1 Liver cancer

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

Biochanin A attenuates spinal cord injury in rats during early stages by inhibiting oxidative stress and inflammasome activation

引用

Neural Regeneration Research 2024年第9期19卷 2050-2056页

作者： Xigong Li Jing Fu Ming guan Haifei shi Wenming Pan Xianfeng Lou Department of Orthopedics The First Affiliated Hospital of Zhejiang UniversityHangzhouZhejiang ProvinceChina Department of Stomatology Xixi HospitalHangzhouZhejiang ProvinceChina Department of Orthopedics and Spine Surgerythe Affiliated Hospital of Xuzhou Medical Schoolthe Second People’s Hospital of ChangshuChangshuJiangsu ProvinceChina

Previous studies have shown that Biochanin A,a flavonoid compound with estrogenic effects,can serve as a neuroprotective agent in the context of cerebral ischemia/reperfusion injury;howeve r,its effect on spinal cord injury is still unclea r. In this study,a rat model of spinal cord injury was established using the heavy o bject impact method,and the rats were then treated with Biochanin A(40 mg/kg) via intrape ritoneal injection for 14 consecutive days.The res ults showed that Biochanin A effectively alleviated spinal cord neuronal injury and spinal co rd tissue injury,reduced inflammation and oxidative stress in spinal cord neuro ns,and reduced apoptosis and pyroptosis.In addition,Biochanin A inhibited the expression of inflammasome-related proteins(ASC,NLRP3,and GSDMD)and the Toll-like receptor 4/nuclear factor-κB pathway,activated the Nrf2/heme oxygenase 1 signaling pathway,and increased the expression of the autophagy markers LC3 Ⅱ,Beclin-1,and P62.Moreove r,the therapeutic effects of Biochanin A on early post-s pinal cord injury were similar to those of methylprednisolone.These findings suggest that Biochanin A protected neurons in the injured spinal cord through the Toll-like receptor 4/nuclear factor κB and Nrf2/heme oxygenase 1 signaling pathways.These findings suggest that Biochanin A can alleviate post-spinal cord injury at an early stage.

关键词： apoptosis autophagy Biochanin A heme oxygenase 1 inflammation Nrf2 protein nuclear factor kappa-B oxidative stress spinal cord injury Toll-like receptor 4

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

Multiscale analysis-based peridynamic simulation of fracture in porous media

引用

Frontiers of Structural and Civil Engineering 2024年第1期18卷 1-13页

作者： Zihao YANG Shangkun SheN Xiaofei guan Xindang he Junzhi CUI School of Mathematics and Statistics Northwestern Polytechnical UniversityXi’an 710072China School of Mathematical Sciences Tongji UniversityShanghai 200092China School of Mechanics Civil Engineering and ArchitectureNorthwestern Polytechnical UniversityXi’an 710072China LSEC ICMSECAcademy of Mathematics and Systems ScienceCASBeijing 100190China

The simulation of fracture in large-scale structures made of porous media remains a challenging task.Current techniques either assume a homogeneous model,disregarding the microstructure characteristics,or adopt a micro-mechanical model,which incurs an intractable computational cost due to its complex stochastic geometry and physical properties,as well as its nonlinear and multiscale features.In this study,we propose a multiscale analysis-based dual-variable-horizon peridynamics(PD)model to efficiently simulate macroscopic structural fracture.The influence of microstructures in porous media on macroscopic structural failure is represented by two PD parameters:the equivalent critical stretch and micro-modulus.The equivalent critical stretch is calculated using the microscale PD model,while the equivalent micro-modulus is obtained through the homogenization method and energy density equivalence between classical continuum mechanics and PD models.Numerical examples of porous media with various microstructures demonstrate the validity,accuracy,and efficiency of the proposed method.

关键词： porous media multiscale variable-horizon peridynamic equivalent critical stretch equivalent micro-modulus

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

Flotation separation of scheelite from calcite using luteolin as a novel depressant

引用

International Journal of Minerals,Metallurgy and Materials 2024年第3期31卷 462-472页

作者： Xiaokang Li Ying Zhang Haiyang he Yu Wu Danyu Wu Zhenhao guan Faculty of Land and Resources Engineering Kunming University of Science and TechnologyKunming 650093China State Key Laboratory of Clean Utilization of Complex Non-Ferrous Metal Resources Kunming University of Science and TechnologyKunming 650093China

This paper proposes luteolin(LUT)as a novel depressant for the flotation-based separation of scheelite and calcite in a sodium oleate(NaOL)system.The suitability of LUT as a calcite depressant is confirmed through micro-flotation testing.At pH=9,with LUT concentration of 50 mg·L^(-1) and NaOL concentration of 50 mg·L^(-1),scheelite recovery reaches 80.3%.Calcite,on the other hand,exhibits a recovery rate of 17.6%,indicating a significant difference in floatability between the two minerals.Subsequently,the surface modifica-tions of scheelite and calcite following LUT treatment are characterized using adsorption capacity testing,Zeta potential analysis,Fourier transform infrared spectroscopy(FT-IR),X-ray photoelectron spectroscopy(XPS),and atomic force microscopy(AFM).The study in-vestigates the selective depressant mechanism of LUT on calcite.Adsorption capacity testing and Zeta potential analysis demonstrate sub-stantial absorption of LUT on the surface of calcite,impeding the further adsorption of sodium oleate,while its impact on scheelite is min-imal.FT-IR and XPS analyses reveal the selective adsorption of LUT onto the surface of calcite,forming strong chemisorption bonds between the hydroxyl group and calcium ions present.AFM directly illustrates the distinct adsorption densities of LUT on the two miner-al types.Consequently,LUT can effectively serve as a depressant for calcite,enabling the successful separation of scheelite and calcite.

关键词： scheelite calcite luteolin flotation depressant separation

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

Safety and effectiveness of butorphanol in epidural labor analgesia:A protocol for a systematic review and meta-analysis

引用

World Journal of Clinical Cases 2024年第8期12卷 1416-1421页

作者： guan-Cheng Tang Man he Zhen-Zhao Huang Yan Cheng Department of Anesthesiology Yongkang Hospital of Traditional Chinese MedicineJinhua 321301Zhejiang ProvinceChina Department of Gynecology and Obstetrics Yongkang Hospital of Traditional Chinese MedicineJinhua 321301Zhejiang ProvinceChina Department of Anesthesiology Hangzhou United Liger Sixth Medical Beauty HospitalHangzhou 311215Zhejiang ProvinceChina Department of Ultrasound Hangzhou Women’s HospitalHangzhou 310008Zhejiang ProvinceChina

BACKGROUND Epidural analgesia is the most effective analgesic method during labor.Butorphanol administered epidurally has been shown to be a successful analgesic method during labor.However,no comprehensive study has examined the safety and efficacy of using butorphanol as an epidural analgesic during labor.AIM To assess butorphanol's safety and efficacy for epidural labor analgesia.METHODS The PubMed,Cochrane Library,EMBASE,Web of Science,China National Knowledge Infrastructure,and Google Scholar databases will be searched from inception.Other types of literature,such as conference abstracts and references to pertinent reviews,will also be reviewed.We will include randomized controlled trials comparing butorphanol with other opioids combined with local anesthetics for epidural analgesia during labor.There will be no language restrictions.The primary outcomes will include the visual analog scale score for the first stage of labor,fetal effects,and Apgar score.Two independent reviewers will evaluate the full texts,extract data,and assess the risk of bias.Publication bias will be evaluated using Egger's or Begg's tests as well as visual analysis of a funnel plot,and heterogeneity will be evaluated using the Cochran Q test,P values,and I2 values.Meta-analysis,subgroup analysis,and sensitivity analysis will be performed using RevMan software version 5.4.This protocol was developed in accordance with the Preferred Reporting Items for Systematic Reviews and Meta-Analyses(PRISMA)Protocols statement,and the PRISMA statement will be used for the systematic review.RESULTS This study provides reliable information regarding the safety and efficacy of using butorphanol as an epidural analgesic during labor.CONCLUSION To support clinical practice and development,this study provides evidence-based findings regarding the safety and efficacy of using butorphanol as an epidural analgesic during labor.

关键词： Epidural analgesia during labor Butorphanol Safety Protocol Meta-analysis

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

Accurate Shortwave Radiation Simulation with a Two-Layer Aerosol Model in Xinjiang Region

引用

Journal of Meteorological Research 2024年第1期38卷 69-87页

作者： guan HUANG Yonghang CheN Qiong LIU Pengtao WANG Qianshan he Qing he Shuai LI Weiling SHAO Ting FAN School of Tourism&Research Institute of Human Geography Xi’an International Studies UniversityXi’an 710128 Center for Silk Road and Eurasian Civilization Studies Xi’an International Studies UniversityXi’an 710128 College of Environmental Science and Engineering Donghua UniversityShanghai 201620 Shanghai Meteorological Service Shanghai 200030 Shanghai Key Laboratory of Meteorology and health Shanghai 200030 Taklimakan Desert Meteorology Field Experiment Station of China Meteorological Administration Institute of Desert MeteorologyUrumqi 830002 Xinjiang Climate Centre Xinjiang Meteorological ServiceUrumqi 830002

To harness the rich solar energy resources in Xinjiang Region of Northwest China,this study tries to address the issue of lack of downward surface shortwave radiation(DSSR)observations and the need to improve the accuracy of satellite retrieval and numerical simulation of DSSR under varied sky and meteorological conditions.(1)A two-layer aerosol model specific to Xinjiang was developed to capture the vertical distributions of aerosols based on multiple data sources including lidar,GPS sounding,ground meteorological observations,and profiles from the ECMWF reanalysis version 5(ERA5)data.The results show that the ERA5/PBLH(planetary boundary layer height)and ERA5/ALH(aerosol layer height)could be used to establish the two-layer aerosol model and characterize the vertical distribution of aerosols in Xinjiang Region.(2)Using the Santa Barbara Discrete Atmospheric Radiative Transfer(SBDART)model,a localized inverse model of clear-sky DSSR was established.After parameter adjustment and using the optimal combination of input parameters for DSSR simulation together with the two-layer aerosol model,the model-simulated DSSR(DSSRSBD)under clear-sky conditions improved significantly compared to the initial results,with all fitting indices greatly improved.(3)In addition,the study demonstrated that the impact of the two-layer aerosol model on DSSR was more pronounced under dust conditions than clear-sky conditions.(4)Using the localized clear-sky DSSR inversion model and its required parameters,simulations were also conducted to capture the spatiotemporal distribution of DSSR under clear-sky conditions in Xinjiang from 2017 to 2019.The annual average DSSR_(SBD)under clear-sky conditions in Xinjiang during 2017–2019 was 606.78 W m^(-2),while DSSR from CERES(DSSR_(CER))under the same conditions was generally higher(703.95 W m^(-2)).(5)It is found that satellite remote sensing products experienced data loss in high-altitude snow areas,where numerical simulation technology could serve as a valuable complement.

关键词： downward surface shortwave radiation(DSSR) aerosol vertical distribution Clouds and the Earth’s Radiant Energy System(CERES) Santa Barbara Discrete Atmospheric Radiative Transfer(SBDART) Xinjiang

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

Subtropical forest macro-decomposers rapidly transfer litter carbon and nitrogen into soil mineral-associated organic matter

引用

Forest Ecosystems 2024年第2期11卷 131-139页

作者： Guoxiang Niu Tao Liu Zhen Zhao Xuebing Zhang Huiling guan Xiaoxiang he Xiankai Lu National Engineering Laboratory for Applied Technology of Forestry and Ecology in South China Central South University of Forestry and TechnologyChangsha410004China Lushan Botanical Garden Chinese Academy of SciencesJiujiang332900China Key Laboratory of Vegetation Restoration and Management of Degraded Ecosystems South China Botanical GardenChinese Academy of SciencesGuangzhou510650China Section of Microbial Ecology Department of BiologyLund UniversityLund22362Sweden Lutou National Station for Scientific Observation and Research of Forest Ecosystem in Hunan Province Yueyang414000China

Background:Forest soils in tropical and subtropical areas store a significant amount of carbon.Recent framework to assess soil organic matter(SOM)dynamics under evolving global conditions suggest that dividing bulk SOM into particulate and mineral-associated organic matter(POM vs.MAOM)is a promising method for identifying how SOM contributes to reducing global warming.Soil macrofauna,earthworms,and millipedes have been found to play an important role in facilitating SOM processes.However,how these two co-existing macrofaunae impac the litter decomposition process and directly impact the formation of POM and MAOM remains unclear.Methods:here,we set up a microcosm experiment,which consisted of 20 microcosms with four treatments earthworm and litter addition(E),millipedes and litter addition(M),earthworm,millipedes,and litter addition(E+M),and control(only litter addition)in five replicates.The soil and litter were sterilized prior to beginning the incubation experiment to remove any existing microbes.After incubating the samples for 42 days,the litte properties(mass,C,and N contents),soil physicochemical properties,as well as the C and N contents,and POM and MAOM^(13)C abundance in the 0–5 and 5–10 cm soil layers were measured.Finally,the relative influences o soil physicochemical and microbial properties on the distribution of C and N in the soil fractions were analyzed Results:The litter mass,C,and N associated with all four treatments significantly decreased after incubation especially under treatment E+M(litter mass:-58.8%,litter C:-57.0%,litter N:-75.1%,respectively),while earthworm biomass significantly decreased under treatment E.Earthworm or millipede addition alone showed no significant effects on the organic carbon(OC)and total nitrogen(TN)content in the POM fraction,but join addition of both significantly increased OC and TN regardless of soil depth.Importantly,all three macrofauna treatments increased the OC and TN content and decreased the^(13)C abundance in the MAOM fraction.More than65%of the total v

关键词： Tropical and subtropical forest Soil organic matter fractions Earthworm Millipedes Litter decomposition

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

The size effect and analogous boundary states in a circular non-hermitian chain

引用

Communications in Theoretical Physics 2024年第2期76卷 157-165页

作者： Xin-Yu Ma Yi-Han guan Qiao-Nan Li Ai-Lei he Lu Qi School of Physical Science and Technology Yangzhou UniversityYangzhou 225002China

We investigate the size effect and boundary states based on a circular non-hermitian chain under the nonreciprocal intra-cell coupling and inter-cell coupling regimes.We find that the circular non-hermitian chain exhibits an even–odd effect on the unit cell corresponding to a large chain,which is different from the open non-hermitian chain only exhibiting the same effect for a small chain.Moreover,we find that the originally localized bulk states become totally extended via designing the boundary coupling strength appropriately.The extended bulk states reveal the fact of the disappearance of the non-hermitian skin effect.In particular,we show that the circular non-hermitian chain also possesses the analogous edge states under some parameter regimes,which is pretty counterintuitive since the circular chain usually cannot define a boundary.Our investigations supply the different non-hermitian phenomena in a circular non-hermitian chain.

关键词： boundary states non-hermitian chain topological state

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：