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Experimental and theoretical study of coupled influence of flow velocity increment and particle size on particle retention and release in porous media

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Water Science and Engineering 2017年第3期10卷 236-245页

作者： xing-xin chen Qi-peng Cai Zhong-han Wu School of Transportation Southeast University School of Civil Engineering Huaqiao University School of Civil Engineering Beijing Jiaotong University

Experimental and theoretical studies were carried out to investigate the coupled influence of flow velocity increment and particle size on the retention and release of particles in porous media. Particle release was examined through measurement of changes in effluent particle concentrations, and particle retention was assessed through measurement of the final spatial distribution of particles remaining in the soil columns after the experiments. Particle release curves were simulated using a convection-dispersion model that includes the instantaneous release of the line source. Fitted model parameters were used to gain insights into the mechanisms that control particle retention and release. When the flow velocity increment was 0.0435 cm/s, the peak concentration of particles decreased with increasing flow velocity until the latter approached a critical level, beyond which the particle concentration increased. Particle wedging and fouling were considered the primary mechanisms that controlled particle retention and release beyond the critical particle velocity. In experiments with large flow velocity increments, small particles exhibited lower particle mass fraction than large particles as particle wedging and fouling increased with particle size. The range of longitudinal dispersivity decreased with an increasing particle size and flow velocity increment. Moreover, the mean particle velocity increased with the mean interstitial fluid velocity. The mean particle velocity profile was highly sensitive to the particle size at low velocity increments. In general,particle release rates increased with both flow velocity and velocity increment. The mass of the released particles provides further evidence that particle wedging and fouling are the major factors that control particle release in sand columns.

关键词： Particle Porous media Retention Release Hydrodynamic force

E-PRedictor: an approach for early prediction of pull request acceptance

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Science China(Information Sciences) 2025年

作者： Kexing chen Lingfeng BAO xing HU xin XIA Xiaohu YANG State Key Laboratory of Blockchain and Data Security Zhejiang University Software Engineering Application Technology Lab

A pull request (PR) is an event in Git where a contributor asks project maintainers to review code he/she wants to merge into a project. The PR mechanism greatly improves the efficiency of distributed software development in the opensource community. Nevertheless, the massive number of PRs in an open-source software (OSS) project increases the workload of developers. To reduce the burden on developers, many previous studies have investigated factors that affect the chance of PRs getting accepted and built prediction models based on these factors. However, most prediction models are built on the data after PRs are submitted for a while (e.g., comments on PRs), making them not useful in practice. Because integrators still need to spend a large amount of effort on inspecting PRs. In this study, we propose an approach named E-PRedictor (earlier PR predictor) to predict whether a PR will be merged when it is created. E-PRedictor combines three dimensions of manual statistic features (i.e., contributor profile, specific pull request, and project profile) and deep semantic features generated by BERT models based on the description and code changes of PRs. To evaluate the performance of E-PRedictor, we collect475192 PRs from 49 popular open-source projects on GitHub. The experiment results show that our proposed approach can effectively predict whether a PR will be merged or not. E-PRedictor outperforms the baseline models (e.g., Random Forest and VDCNN) built on manual features significantly. In terms of F1@Merge, F1@Reject, and AUC (area under the receiver operating characteristic curve), the performance of E-PRedictor is 90.1%, 60.5%, and 85.4%, respectively.

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Boron shielding design for neutron and gamma detectors of a pulsed neutron tool

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Nuclear Science and Techniques 2025年第1期36卷 115-126页

作者： xin-Yang Wang Jun-Yan chen Qiong Zhang University of Electronic Science and Technology of China Chengdu 611731China

Shielding materials are critical for downhole pulsed neutron tool design because they directly influence the accuracy of formation measurements.A well-designed shield configuration ensures that the response of the tool is maximally representative of the formation without being affected by the tool and borehole *** study investigated the effects of boron-containing materials on neutron and gamma detectors based on a newly designed logging-while-drilling tool that is currently undergoing *** the boron content increased,the ability to absorb thermal neutrons increased *** simulation,it was proven that boron carbide(B_(4)C)can be used as an effective boron shielding material for thermal neutrons,and is therefore employed in this *** shield against thermal neutrons migrating from the mud pipes,the optimal shielding thicknesses for the near-and far-neutron detectors were determined to be 5 and 4 *** a porosity of 25 p.u.,near-neutron sensitivity exhibited a 5.6%***,to shield the capture gamma generated by thermal neutrons once they enter the tool from the mud pipe and formation,internal and external shields for the gamma detector were *** results show that the internal shield requires a boron content of 75%,whereas the external shield has a thickness of 14.2 mm thickness and a boron content of 25%to minimize the tool effect.

关键词： Nuclear well logging Pulsed neutron tool Boron shielding

Pharmacokinetics and the bystander effect in CD：：UPRT/5-FC bi-gene therapy of glioma

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Chinese Medical Journal 2009年第11期122卷 1267-1272页

作者： SHI De-zhi HU Wei-xing LI Li-xin chen Gong WEI Dong GU Pei-yuan Department of Neurosurgery First Affiliated Hospital of Nanjing Medical University Nanjing Jiangsu 210029 China

Background Cytosine deaminase （CD） converts 5-fluorocytosine （5-FC） to 5-fluorouracil （5-FU） in CD/5-FC gene therapy, 5-FU will be mostly converted into nontoxic 13-alanine without uracil phosphoribosyltransferase （UPRT）. UPRT catalyzes the conversion of 5-FU to 5-fluorouridine monophosphate, which directly kills CD：：UPRT-expressing cells and surrounding cells via the bystander effect. But the pharmacokinetics and the bystander effect of CD：：UPRT/5-FC has not been verified in vivo and in vitro. Before the CD：：UPRT/5-FC bi-gene therapy system is used in clinical trial, it is essential to monitor the transgene expression and function in vivo. Thus, we developed a preclinical tumor model to investigate the feasibility of using ^19F-magnetic resonance spectroscopy （^19F-MRS） and optical imaging to measure non-invasive CD and UPRT expression and its bystander effect. Methods C6 and C6-CD：：UPRT cells were cultured with 5-FC. The medium, cells and their mixture were analyzed by ^19F-MRS. Rats with intracranial xenografted encephalic C6-CD：：UPRT glioma were injected intraperitoneally with 5-FC and their ^19F-MRS spectra recorded. Then the pharmacokinetics of 5-FC was proved. Mixtures of C6 and C6-CD：：UPRT cells at different ratios were cultured with 5-FC and the cytotoxic efficacy and survival rate of cells recorded. To determine the mechanism of the bystander effect, the culture media from cell comprising 25% and 75% C6-CD：：UPRT cells were examined by ^19F-MRS. A comparative study of mean was performed using analysis of variance （ANOVA）. Results ^19F-MRS on samples from C6-CD：：UPRT cells cultured with 5-FC showed three broad resonance signals corresponding to 5-FC, 5-FU and fluorinated nucleotides （F-Nuctd）. For the C6 mixture, only the 5-FC peak was detected. In vivo serial ^19F-MRS spectra showed a strong 5-FC peak and a weak 5-FU peak at 20 minutes after 5-FC injection. The 5-FU concentration reached a maximum at about 50 minutes. The F-Nuctd signal appeared after about

关键词： glioma cytosine deaminase uracil phosphoribosyltransferase pharmacokinetics magnetic resonance spectroscopy bystander effect

Grounded-source short offset transient electromagnetic method:Theory and applications in deep mineral exploration

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Science China Earth Sciences 2025年第2期68卷 626-638页

作者： Guoqiang XUE xin WU Weiying chen Nannan ZHOU Key Laboratory of Mineral Resources Institute of Geology and GeophysicsChinese Academy of SciencesBeijing 100029China College of Earth and Planetary Sciences University of Chinese Academy of SciencesBeijing 100049China

The Transient Electromagnetic(TEM)method is a critical geophysical technique for subsurface exploration of metal ore bodies,primarily utilizing either loop or grounded *** Long Offset Transient Electromagnetic(LOTEM)method employs a grounded-source transmitter,relying on a far-source observation mode and plane wave approximation for ***,LOTEM's far-source configuration weakens signal strength,and the plane wave approximation reduces precision,limiting effective detection depth to approximately 1000 m with a comprehensive error of about 15%.Recently,we have developed the grounded-source Short Offset Transient Electromagnetic(SOTEM)method,achieving greater detection depth and accuracy within the 500–2000 m depth range,a crucial interval for mineral resource *** study explores the theoretical framework,instrumentation,data processing,and field applications of *** on a point charge element model,SOTEM accurately computes surface wave effects in EM field calculations,optimized for near-source ***-power,high-resolution,wide-bandwidth exploration equipment and an advanced three-dimensional hybrid inversion technique were also developed to enhance the method's *** of SOTEM to the deep exploration of the Zhou'an Ni-Cu-PGE deposit in Henan Province yielded high-resolution imaging of conductivity structures to about 2.5 km *** results,consistent with existing drill data,delineated mineralized ore bodies from surrounding formations,identified zones of mineralization potential,and suggested extensive resource prospects in the region.

关键词： Far-source observation Plane wave model approximation Grounded-source short-offset transient electromagnetic method Wide-bandwidth exploration equipment Three-dimensional hybrid inversion

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Post-tunable salt gel electrolytes toward flexible supercapacitor switches

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Journal of Energy Chemistry 2025年第1期100卷 114-124页

作者： Hui Wang Shuang chen Xuming Liu Qin Zhang xin Liu Polymeric and Soft Materials Laboratory School of Chemistry and Life Science and Advanced Institute of Materials ScienceChangchun University of TechnologyChangchun 130012JilinChina Polymeric and Soft Materials Laboratory School of Chemical Engineering and Advanced Institute of Materials ScienceChangchun University of TechnologyChangchun 130012JilinChina

Convertible hydrogel supercapacitors have emerged as promising energy storage devices in switches,diodes,and ***,inherent weaknesses in ionic conductivity,mechanical properties,and water retention of hydrogel electrolytes seriously hinder their *** by the hardness conversion of sea cucumber skin,a conductivity and mechanics dual-tunable salt gel electrolyte is successfully *** salt gel presents a reversible switching of conductors-insulators and a mechanical regulation between softness and hardness via the dissolution-crystallization transition of sodium acetate trihydrate(SAT).Meanwhile,the salt gels spontaneously grow a layer of“armor”through saturated phase-change salt crystals effectively reducing water evaporation of hydrogel ***,this phase-change soft-rigid conversion strategy will expand the capabilities of gel-based flexible supercapacitors(area capacitance:258.6 mF cm^(-2)),and the capacitance retention rate could still reach 86.9%after 3000 cycles at high ***,the salt gel supercapacitor is potentially used in over-heat alarm *** is anticipated that the strategy of conductivity and mechanics of dual-tunable salt gel would provide a new perspective on the development of energy storage devices,wearable electronics,and flexible robots.

关键词： Supercapacitors Salt gels Reversible phase transition Post-tuning Conductivity switching

Exploring the potential of extrachromosomal DNA as a novel oncogenic driver

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Science China(Life Sciences) 2025年第1期68卷 144-157页

作者： Huanbo Zhu Longtao Huangfu Junbing chen Jiafu Ji Xiaofang xing Key Laboratory of Carcinogenesis and Translational Research(Ministry of Education/Beijing) Division of Gastrointestinal Cancer Translational Research LaboratoryPeking University Cancer Hospital&InstituteBeijing 100142China Department of Gastrointestinal Cancer Center Peking University Cancer Hospital&InstituteBeijing 100142China Department of Liver Surgery&Transplantation Liver Cancer InstituteZhongshan HospitalFudan UniversityKey Laboratory of Carcinogenesis and Cancer InvasionMinistry of EducationShanghai200032China State Key Laboratory of Holistic Integrative Management of Gastrointestinal Cancers Beijing Key Laboratory of Carcinogenesis and Translational ResearchDivision of Gastrointestinal Cancer Translational Research LaboratoryPeking University Cancer Hospital&InstituteBeijing 100142China

Extrachromosomal DNA(ecDNA)is a form of circular DNA mostly found in tumor *** the typical chromosomal DNA,ecDNA is circular,self-replicating,and carries complete or partial gene *** ecDNA occurrence remains a rare event in cancer,recent studies have shown that oncogene amplification on ecDNA is widespread throughout many types of cancer,implying that ecDNA plays a central role in accelerating tumor *** has also been associated with increased tumor mutation burden,chromosomal instability,and even tumor microenvironment *** may be crucial in influencing tumor heterogeneity,drug sensitivity,oncogenic senescence,and tumor immunogenicity,leading to a worsening prognosis for tumor *** this way,several clinical trials have been conducted to investigate the importance of ecDNA in clinical *** this review,we summarize the biogenesis,characteristics,and current research methods of ecDNA,discuss the vital role of ecDNA-caused tumor heterogeneity in cancers,and highlight the potential role of ecDNA in cancer therapy.

关键词： extrachromosomal DNA cancer therapy tumor heterogeneity drug resistance tumor evolution

Advancements and challenges in esophageal carcinoma prognostic models:A comprehensive review and future directions

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World Journal of Gastrointestinal Oncology 2025年第2期17卷 311-314页

作者： Jia chen Qi-Chang xing Department of Clinical Pharmacy Xiangtan Central HospitalXiangtan 411100Hunan ProvinceChina The Affiliated Hospital Hunan UniversityChangsha 410082Hunan ProvinceChina

In this article,we comment on the article published by Yu et *** employing LASSO regression and Cox proportional hazard models,the article identified nine significant variables affecting survival,including body mass index,Karnofsky performance status,and tumor-node-metastasis *** firmly concur with Yu et al regarding the vital significance of clinical prediction models(CPMs),including logistic regression and Cox regression for assessment in esophageal carcinoma(EC).However,the nomogram's limitations and the complexities of integrating genetic factors pose *** integration of immunological data with advanced statistics offers new research ***-throughput sequencing and big data,facilitated by machine learning,have revolutionized cancer research but require substantial computational *** future of CPMs in EC depends on leveraging these technologies to improve predictive accuracy and clinical application,addressing the need for larger datasets,patientreported outcomes,and regular updates for clinical relevance.

关键词： Predictive model Machine learning Esophageal carcinoma Survival rate Factors

Unraveling the therapeutic potential of Calculus Bovis in liver cancer:A novel step for targeted cancer treatment

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World Journal of Gastroenterology 2025年第3期31卷 127-129页

作者： xing-Yu chen Xiang Lan Department of Hepatobiliary Surgery The First Affiliated Hospital of Chongqing Medical UniversityChongqing 400016China

Hepatocellular carcinoma is one of the leading causes of cancer-related deaths globally,and effective treatments are urgently *** present study aimed to investigate the inhibitory effect of Calculus Bovis(CB)on liver cancer and the underlying *** inhibited M2 tumor-associated macrophage polarization and modulated the Wnt/β-catenin signaling pathway,thereby suppressing the proliferation of liver cancer *** inhibitory effect on liver cancer growth was confirmed by both in vivo and in vitro experiments(detailed by Huang et al).The present study provides a theoretical basis for the application of CB for the treatment of liver cancer,providing new avenues for liver cancer treatment.

关键词： Calculus Bovis Liver cancer M2 tumor-associated macrophage polarization Wnt/β-catenin Pathway Tumor microenvironment