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海藻酸钠/四硼酸钠水溶液的流变性能
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作者 朱雷 程敏 +2 位作者 李晓俊 程春祖 徐纪刚 《高分子材料科学与工程》 北大核心 2025年第5期104-112,共9页
在海藻酸钠(SA)/四硼酸钠(STB)水溶液中,STB会影响SA分子间及分子内化学键的形成,进而改变其溶液的流变响应。为探究SA/STB溶液的流变性与可纺性变化规律,研究了STB浓度、体系温度、SA单元组成等因素对溶液流变行为的影响。结果表明,SA... 在海藻酸钠(SA)/四硼酸钠(STB)水溶液中,STB会影响SA分子间及分子内化学键的形成,进而改变其溶液的流变响应。为探究SA/STB溶液的流变性与可纺性变化规律,研究了STB浓度、体系温度、SA单元组成等因素对溶液流变行为的影响。结果表明,SA与STB发生了共价交联,SA/STB溶液为假塑性流体。表观黏度、结构黏度指数、黏流活化能和动态模量随温度升高而减小,随STB浓度增大而增大,非牛顿指数则相反。高M/G比值的SA/STB溶液可纺性较好、对温度更敏感,升温和提高剪切速率可改善低M/G比值溶液的流动性,加工成型时可按实际情况选择合适的交联剂浓度和温度条件。 展开更多
关键词 海藻酸钠 温度 M/G比值 四硼酸钠浓度 稳态流变 动态流变
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Synergistic solvation and interphase design via a steric-electronic additive for ultra-long cycling lithium metal batteries
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作者 min cheng Xu Zhou +1 位作者 Yuhang Liang Yuanhui Zheng 《Journal of Energy Chemistry》 2025年第9期759-768,I0020,共11页
The electrochemical instability of traditional ether-based electrolytes poses a challenge for their use in high-voltage lithium metal batteries.Herein,a synergetic optimization strategy was proposed by introducing an ... The electrochemical instability of traditional ether-based electrolytes poses a challenge for their use in high-voltage lithium metal batteries.Herein,a synergetic optimization strategy was proposed by introducing an additive with a strong electron-withdrawing group and significant steric hindrance-isosorbide dinitrate(ISDN),reconstructing the solvation structure and solid electrolyte interphase(SEI),enabling highly stable and efficient lithium metal batteries.We found that ISDN can strengthen the interaction between Li^(+)and the anions of lithium salts and weaken the interaction between Li^(+)and the solvent in the solvation structure.It promotes the formation of a LiF-rich and LiN_(x)O_(y)-rich SEI layer,enhancing the uniformity and compactness of Li deposition and inhibiting solvent decomposition,which effectively expands the electrochemical window to 4.8 V.The optimized Li‖Li cells offer stable cycling over 1000 h with an overpotential of only 57.7 mV at 1 mA cm^(-2).Significantly,Li‖3.7 mA h LiFePO_(4)cells retain 108.3%of initial capacity after 546 cycles at a rate of 3 C.Under high-loading conditions(Li‖4.9 mA h LiNi_(0.8)Co_(0.1)Mn_(0.1)O_(2)full cells)and a cutoff voltage of 4.5 V,the ISDN-containing electrolyte enables stable cycling for 140 cycles.This study leverages steric hindrance and electron-withdrawing effect to synergistically reconstruct the Li^(+)solvation structure and promote stable SEI formation,establishing a novel electrolyte paradigm for high-energy lithium metal batteries. 展开更多
关键词 Electrolyte additives Steric-electronic synergy Dual-function optimization Solvation structure Solid electrolyte interphase Lithium metal anodes
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Rational design and synthesis of upconversion luminescence-based optomagnetic multifunctional nanorattles for drug delivery
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作者 Xuhua Liang Yanyan Zhao +1 位作者 min cheng Fei Zhang 《Chinese Journal of Chemical Engineering》 SCIE EI CAS CSCD 2021年第10期286-293,共8页
Optomagnetic multifunctional composite based on upconversion luminescence nanomaterial is regarded as a promising strategy for bioimaging,disease diagnosis and targeted delivery of drugs.To explore a mesoporous nanost... Optomagnetic multifunctional composite based on upconversion luminescence nanomaterial is regarded as a promising strategy for bioimaging,disease diagnosis and targeted delivery of drugs.To explore a mesoporous nanostructure with excellent water dispersibility and high drug-loading capacity,a novel nanorattle-structured Fe3O4@SiO2@NaYF4:Yb,Er magnetic upconversion nanorattle(MUCNR)was successfully designed by using Fe3O4 as core and NaYF4:Yb,Er nanocrystals as shell.The microstructures and crystal phase of the as-prepared MUCNRs were evaluated by transmission electron microscopy,Xray powder diffraction and N2 adsorption/desorption isotherms.The Kirkendall effect was adapted to explain the formation mechanism of the MUCNRs.The loading content and encapsulation efficiency of doxorubicin hydrochloride(DOX)could reach as high as 18.2%and 60.7%,respectively.Moreover,the DOX loading MUCNR(DOX-MUCNR)system showed excellent sustained drug release and strong p Hdependent performance,which was conducive to drug release at the slightly acidic microenvironment of tumor.Microcalorimetry was used to quantify the interactions between the carrier structure and drug release rate directly.The heat release rates in the heat-flow diagrams are basically consistent with the DOX release rate,thereby showing that microcalorimetry assay not only provides a unique thermodynamic explanation for the structure–activity relationship of Fe3O4@SiO2@NaYF4:Yb,Er MUCNRs but also provides powerful guidance to avoid the blind selection or design of drug carriers.Therefore,our work firmly provided a comprehensive perspective for using Fe3O4@SiO2@NaYF4:Yb,Er MUCNRs as a remarkable magnetic targeted drug carrier. 展开更多
关键词 Optomagnetic nanocomposite Nanorattle Upconversion luminescence Iron oxide Drug delivery
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重要小分子的光解离和光电离微观动力学
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作者 程敏 张丽娟 +2 位作者 徐西玲 高蕻 郑卫军 《化学进展》 CSCD 北大核心 2024年第12期1830-1848,共19页
小分子光解离和光电离的微观反应机理研究,是分子反应动力学研究领域的核心和焦点之一,具有重要的理论意义和应用价值。它不仅可揭示分子与光相互作用的物理化学本质,还有助于从量子层次认识化学反应并最终调控化学反应过程。本文系统... 小分子光解离和光电离的微观反应机理研究,是分子反应动力学研究领域的核心和焦点之一,具有重要的理论意义和应用价值。它不仅可揭示分子与光相互作用的物理化学本质,还有助于从量子层次认识化学反应并最终调控化学反应过程。本文系统回顾了朱起鹤院士团队多年来在该领域取得的研究成果。他们利用自主研制的多台分子光解碎片平动能谱仪,通过测量光解碎片的平动能分布和空间角分布,深入研究了一系列卤代烃在A带的光解动力学特性,揭示了其光解规律和微观反应机理。利用自行搭建的共振增强多光子电离和质量解析阈值电离光谱仪,结合量子化学计算,他们系统研究了一系列苯衍生物在不同电子态的几何构型、振动光谱、跃迁能和电离能等,总结了多卤素效应、取代基效应、构象异构效应等对分子性质及其光谱的影响规律,为揭示分子激发态、离子态的特性提供了重要信息。这些研究不仅深化了对化学反应微观机理的理解,还为大气化学、环境化学、生物化学和材料科学等领域的实际应用提供了重要的理论依据。 展开更多
关键词 光解离 光电离 卤代烃 苯衍生物
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Intervention control of aerobic exercise in maintaining quality of life and pulmonary hypertension in hemodialysis patients 被引量:1
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作者 Dan-Dan Wang min cheng Chun-Ying Chen 《World Journal of Clinical Cases》 SCIE 2024年第20期4217-4229,共13页
BACKGROUND Pulmonary hypertension is a serious complication in the treatment of maintenance hemodialysis patients,which seriously affects the quality of life of patients and threatens their life safety.Prevention,trea... BACKGROUND Pulmonary hypertension is a serious complication in the treatment of maintenance hemodialysis patients,which seriously affects the quality of life of patients and threatens their life safety.Prevention,treatment and improvement of pulmonary hypertension are of great significance to improve the quality of life of patients.AIM To investigate the intervention and control of pedal-powered bicycle in maintaining quality of life and pulmonary hypertension in hemodialysis patients.METHODS 73 patients with maintenance hemadialysis combined with pulmonary arterial hypertension at a hemodialysis center in a certain hospital from May 2021 to May 2022 are selected.Patients are divided into two groups,37 cases in the control group(group C)and 36 cases in the intervention group(group I).Patients are divided into two groups,group C is treated with oral administration of betaglandin sodium combined with routine nursing care.Based on group C,group I conducts power cycling exercises.RESULTS After treatment,group I patients had higher muscle strength,36-Item Short Form Health Survey scores,and Kidney Disease Targets Areas scores;The 6-minute walk distance test index level was higher and the Borg score was lower;The group I had lower systolic blood pressure,greater vital capacity,higher positive emotion,lower systolic pulmonary artery pressure index level,higher arterial partial oxygen pressure level,lower pulmonary vascular resistance index level,and higher blood oxygen saturation level[158.91±11.89 vs 152.56±12.81,1795.01±603.18 vs 1907.20±574.15,24.00(22.00,29.00)vs 24.00(22.00,28.00),P<0.001].CONCLUSION Aerobic exercise combined with Western medicine treatment can effectively improve patients'pulmonary hypertension,alleviate their negative emotions,and enable them to achieve a higher level of quality of life. 展开更多
关键词 Aerobic exercise HEMODIALYSIS Pulmonary arterial hypertension Cycle ergometer Quality of life
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Intramolecular Hydrogen Bond Improved Durability and Kinetics for Zinc‑Organic Batteries
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作者 Tianjiang Sun Jun Pan +5 位作者 Weijia Zhang Xiaodi Jiang min cheng Zhengtai Zha Hong Jin Fan Zhanliang Tao 《Nano-Micro Letters》 SCIE EI CSCD 2024年第3期138-148,共11页
Organic compounds have the advantages of green sustainability and high designability,but their high solubility leads to poor durability of zinc-organic batteries.Herein,a high-performance quinone-based polymer(H-PNADB... Organic compounds have the advantages of green sustainability and high designability,but their high solubility leads to poor durability of zinc-organic batteries.Herein,a high-performance quinone-based polymer(H-PNADBQ)material is designed by introducing an intramolecular hydrogen bonding(HB)strategy.The intramolecular HB(C=O⋯N-H)is formed in the reaction of 1,4-benzoquinone and 1,5-naphthalene diamine,which efficiently reduces the H-PNADBQ solubility and enhances its charge transfer in theory.In situ ultraviolet-visible analysis further reveals the insolubility of H-PNADBQ during the electrochemical cycles,enabling high durability at different current densities.Specifically,the H-PNADBQ electrode with high loading(10 mg cm^(-2))performs a long cycling life at 125 mA g^(-1)(>290 cycles).The H-PNADBQ also shows high rate capability(137.1 mAh g^(−1)at 25 A g^(−1))due to significantly improved kinetics inducted by intramolecular HB.This work provides an efficient approach toward insoluble organic electrode materials. 展开更多
关键词 Zn-organic batteries H-PNADBQ polymer Intramolecular hydrogen bond Reduced solubility Improvedπ-conjugated level
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^(14)N_(2)和^(15)N_(2)在解离通道N(^(2)D_(5/2,3/2))+N(^(2)D_(5/2,3/2))阈值以上光解离产物精细结构分支比N(^(2)D_(5/2))/N(^(2)D_(3/2))的测量
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作者 芦丽亚 蒋攀 +1 位作者 程敏 高蕻 《Chinese Journal of Chemical Physics》 SCIE EI CAS CSCD 2024年第2期264-270,I0102,I0103,共9页
精确测量解离产物的自旋-轨道耦合精细结构分支比对于进一步了解小分子的光解动力学具有十分重要的意义。本文利用真空紫外泵浦-真空紫外探测时间切片离子速度成像装置,测量了^(14)N_(2)的c4′1∑_(u)^(+)(v′=6)态和b′1∑_(u)^(+)(v′... 精确测量解离产物的自旋-轨道耦合精细结构分支比对于进一步了解小分子的光解动力学具有十分重要的意义。本文利用真空紫外泵浦-真空紫外探测时间切片离子速度成像装置,测量了^(14)N_(2)的c4′1∑_(u)^(+)(v′=6)态和b′1∑_(u)^(+)(v′=21)态以及^(15)N_(2)的b′∑_(u)^(0)(=20)态和b′1∑_(u)^(+)(v′=20)态和b′1∑_(u)^(+)(v′=21)解离至通道N(2D_(5/2,3/2))+N(2D_(5/2.3/2))产物精细结构分支比N(2D_(5/2))/N(2D_(3/2)).实验结果表明,产物精细结构分支比N(2D_(5/2))/N(2D_(3/2))与^(14)N_(2)或^(15)N_(2)所在的转动能级无关而与其电子态和振动能级的性质有关。^(14)N_(2)的c4′1∑_(u)^(+)(v′=6)态和^(15)N_(2)的b′1∑_(u)^(+)(v′=20)态均接近解离通道N(2D_(5/2,3/2))+N(2D_(5/2,3/2))的阈值,产物精细结构分支比N(2D_(5/2))/N(2D_(3/2))数值均为-1.35;而^(14)N_(2)和^(15)N_(2)的b′∑_(u)^(+)(v′=21)态均远高于解离通道N(2D_(5/2,3/2))+N(2D_(5/2,3/2))的阈值,产物精细结构分支比N(2D_(5/2))/N(2D_(3/2))数值均为-1.00.本文猜测氮气在接近解离通道值时是一个遵循统计规律的解离过程,而在远高于解离通道阈值时是一个非绝热过程,这可能是本实验中观测到的产物精细结构分支比振动依赖现象的原因.要定量解释本实验的测量结果,需要在该解离通道阈值附近的氮气高精度势能曲线及其相互作用信息。 展开更多
关键词 精细结构分支比 真空紫外光 氮气分子 光解离动力学 科里奥利作用
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Sorbitol-Electrolyte-Additive Based Reversible Zinc Electrochemistry
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作者 Qiong Sun Hai-Hui Du +5 位作者 Tian-Jjiang Sun Dian-Tao Li min cheng Jing Liang Hai-Xia Li Zhan-Liang Tao 《电化学(中英文)》 CAS 北大核心 2024年第7期28-37,共10页
The unstable zinc(Zn)/electrolyte interfaces formed by undesired dendrites and parasitic side reactions greatly hinder the development of aqueous zinc ion batteries.Herein,the hydroxy-rich sorbitol was used as an addi... The unstable zinc(Zn)/electrolyte interfaces formed by undesired dendrites and parasitic side reactions greatly hinder the development of aqueous zinc ion batteries.Herein,the hydroxy-rich sorbitol was used as an additive to reshape the solvation structure and modulate the interface chemistry.The strong interactions among sorbitol and both water molecules and Zn electrode can reduce the free water activity,optimize the solvation shell of water and Zn^(2+)ions,and regulate the formation of local water(H_(2)O)-poor environment on the surface of Zn electrode,which effectively inhibit the decomposition of water molecules,and thus,achieve the thermodynamically stable and highly reversible Zn electrochemistry.As a result,the assembled Zn/Zn symmetric cells with the sorbitol additive realized an excellent cycling life of 2000 h at 1 mA·cm^(-2)and 1 mAh·cm^(-2),and over 250 h at 5 mA.cm^(-2)and 5 mAh.cm^(-2).Moreover,the Zn/Cu asymmetric cells with the sorbitol additive achieved a high Coulombic efficiency of 99.6%,obtaining a better performance than that with a pure 2 mol-L^(-1)ZnSO_(4)electrolyte.And the constructed Zn/poly1,5-naphthalenediamine(PNDA)batteries could be stably discharged for 2300 cycles at 1 A g^(-1)with an excellent capacity retention rate.This result indicates that the addition of 1 mol-L^(-1)non-toxic sorbitol into a conventional ZnSO_(4)electrolyte can successfully protect the Zn anode interface by improving the electrochemical properties of Zn reversible deposition/decomposition,which greatly promotes its cycle performance,providing a new approach in future development of high performance aqueous Zn ion batteries. 展开更多
关键词 Aqueous zinc ion batteries DENDRITE Sorbitol additive Solvation regulation Interface modulation
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Correlation between cerebral neurotransmitters levels by proton magnetic resonance spectroscopy and HbA1c in patients with type 2 diabetes
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作者 Xiang-Yu Gao Chen-Xia Zhou +5 位作者 Hong-Mei Li min cheng Da Chen Zi-Yi Li Bo Feng Jun Song 《World Journal of Diabetes》 SCIE 2024年第6期1263-1271,共9页
BACKGROUND Cognitive dysfunction is the main manifestation of central neuropathy.Although cognitive impairments tend to be overlooked in patients with diabetes mellitus(DM),there is a growing body of evidence linking ... BACKGROUND Cognitive dysfunction is the main manifestation of central neuropathy.Although cognitive impairments tend to be overlooked in patients with diabetes mellitus(DM),there is a growing body of evidence linking DM to cognitive dysfunction.Hyperglycemia is closely related to neurological abnormalities,while often disregarded in clinical practice.Changes in cerebral neurotransmitter levels are associated with a variety of neurological abnormalities and may be closely related to blood glucose control in patients with type 2 DM(T2DM).AIM To evaluate the concentrations of cerebral neurotransmitters in T2DM patients exhibiting different hemoglobin A1c(HbA1c)levels.METHODS A total of 130 T2DM patients were enrolled at the Department of Endocrinology of Shanghai East Hospital.The participants were divided into four groups according to their HbA1c levels using the interquartile method,namely Q1(<7.875%),Q2(7.875%-9.050%),Q3(9.050%-11.200%)and Q4(≥11.200%).Clinical data were collected and measured,including age,height,weight,neck/waist/hip circumferences,blood pressure,comorbidities,duration of DM,and biochemical indicators.Meanwhile,neurotransmitters in the left hippocampus and left brainstem area were detected by proton magnetic resonance spectroscopy.RESULTS The HbA1c level was significantly associated with urinary microalbumin(mALB),triglyceride,low-density lipoprotein cholesterol(LDL-C),homeostasis model assessment of insulin resistance(HOMA-IR),and beta cell function(HOMA-β),N-acetylaspartate/creatine(NAA/Cr),and NAA/choline(NAA/Cho).Spearman correlation analysis showed that mALB,LDL-C,HOMA-IR and NAA/Cr in the left brainstem area were positively correlated with the level of HbA1c(P<0.05),whereas HOMA-βwas negatively correlated with the HbA1c level(P<0.05).Ordered multiple logistic regression analysis showed that NAA/Cho[Odds ratio(OR):1.608,95%confidence interval(95%CI):1.004-2.578,P<0.05],LDL-C(OR:1.627,95%CI:1.119-2.370,P<0.05),and HOMA-IR(OR:1.107,95%CI:1.031-1.188,P<0.01)were independent predictors of poor glycemic control.CONCLUSION The cerebral neurotransmitter concentrations in the left brainstem area in patients with T2DM are closely related to glycemic control,which may be the basis for the changes in cognitive function in diabetic patients. 展开更多
关键词 Type 2 diabetes mellitus Hemoglobin A1c Proton magnetic resonance spectroscopy NEUROTRANSMITTERS Central neuropathy
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Analysis of the impacts of reactant molecular beam velocity spreads on product velocity resolution in crossed beam experiments
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作者 Yufan Ding min cheng Hong Gao 《Chinese Journal of Chemical Physics》 CSCD 2024年第6期814-822,I0042,I0043,共11页
Owing to its convenience and accuracy in providing detailed information about quantum state populations and angular distributions of reaction products,the velocity map imaging technique has been extensively employed i... Owing to its convenience and accuracy in providing detailed information about quantum state populations and angular distributions of reaction products,the velocity map imaging technique has been extensively employed in crossed beam experiments for product detection.In crossed beam experiments,the two reactant beams always exhibit certain spreads in both magnitude and direction of the velocity,which will blur the scattered product images and lower the resolution of product detection.To systematically investigate the influence of reactant velocity spreads on the resolution of product detection in crossed beam experiments,a general model based on velocity vector analysis is constructed and presented here.The impacts of spreads of the magnitude and direction of the reactant velocities on the image resolution under three typical experimental conditions are analyzed,and ways for improving the resolution are briefly discussed.Guided by the above analysis,a fine adjustment of the Ar^(+)ion beam was performed,and the product image resolution for the charge transfer reaction Ar^(+)(^(2)P_(3/2))+N_(2)is effectively improved,particularly in the backward scattering region,which provides more accurate information on the reaction dynamics. 展开更多
关键词 Crossed molecular beam Molecular beam Velocity-map imaging Monte Carlo simulation Product velocity resolution
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用户特征聚类和ICSA-SVR台区负荷预测 被引量:5
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作者 滕永兴 杨霖 +2 位作者 钟睿君 闵诚 李祺 《中国测试》 CAS 北大核心 2022年第7期107-113,共7页
为提高配电网负荷预测精度,提出一种将模糊C均值(FCM)聚类与改进乌鸦搜索算法(ICSA)优化支持向量回归机(SVR)相结合的低压台区负荷预测模型。利用FCM算法对台区用户用电特征进行提取和聚类,消除用电行为特性差异对预测精度的影响,并构建... 为提高配电网负荷预测精度,提出一种将模糊C均值(FCM)聚类与改进乌鸦搜索算法(ICSA)优化支持向量回归机(SVR)相结合的低压台区负荷预测模型。利用FCM算法对台区用户用电特征进行提取和聚类,消除用电行为特性差异对预测精度的影响,并构建ICSA-SVR模型,对各类用户的用电负荷进行回归预测,进而叠加得到台区负荷预测结果。结果显示,台区内不同类型用户之间的用电特性差异较大,可分冬季单峰型、夏季单峰型和冬夏双峰型三类,各台区负荷呈现不同的季节性波动;该方法能够明显提升台区负荷预测精度,预测结果可对电力生产运营提供指导。 展开更多
关键词 低压台区 负荷预测 特征聚类 乌鸦搜索算法 支持向量回归
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基于多目标改进免疫算法和GIS的养老机构空间配置优化研究——以上海市虹口区为例 被引量:22
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作者 程敏 崔晓 《地理科学》 CSSCI CSCD 北大核心 2018年第12期2049-2057,共9页
综合考虑政府、居民、投资者3方需求,构建带约束多目标的养老机构配置优化模型,基于改进免疫算法和GIS技术,对上海市虹口区养老机构的配置优化问题进行研究,分析研究区现有养老机构在空间分布和规模配置上的合理性,提出优化配置方案。... 综合考虑政府、居民、投资者3方需求,构建带约束多目标的养老机构配置优化模型,基于改进免疫算法和GIS技术,对上海市虹口区养老机构的配置优化问题进行研究,分析研究区现有养老机构在空间分布和规模配置上的合理性,提出优化配置方案。研究表明:研究区现有养老机构数量缺口较大、部分养老机构偏离最佳区位、规模与需求存在较大差距;3所位于江湾镇街道的养老机构在现有区位运行欠合理;为充分满足居民养老需求,需在虹口区南部地区增设15所养老机构;通过与一般免疫算法、遗传算法、粒子群算法、模拟退火算法得到的优化结果对比可知,改进免疫算法在此优化问题中的求解效率分别提高45%,38.89%,21.43%,46.34%,求解精度分别提高1.61%,2.73%,5.80%,6.91%。 展开更多
关键词 养老机构 配置优化 改进免疫算法 GIS 多目标
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CO_(2)/N_(2)二元气体对甲烷在煤中吸附影响的分子模拟研究 被引量:10
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作者 孙致学 闵成 +3 位作者 张婉露 蒋永平 于雪峰 崔彬 《煤田地质与勘探》 CAS CSCD 北大核心 2022年第3期127-136,共10页
二元气驱技术(CO_(2)/N_(2)-ECBM)已成为煤层气增产的重要手段,明确CO_(2)/N_(2)在煤层中的竞争吸附规律以及对煤层物性的影响具有重大意义。利用分子模拟软件Materials Studio建立延川南煤层气实际区块温度、压力条件下的煤分子模型。... 二元气驱技术(CO_(2)/N_(2)-ECBM)已成为煤层气增产的重要手段,明确CO_(2)/N_(2)在煤层中的竞争吸附规律以及对煤层物性的影响具有重大意义。利用分子模拟软件Materials Studio建立延川南煤层气实际区块温度、压力条件下的煤分子模型。基于巨正则蒙特卡洛(GCMC)方法研究CO_(2)/N_(2)交替驱替煤层气技术中各注入阶段对CH_(4)吸附的影响,明确CO_(2)、N_(2)对煤层孔渗物性的影响规律。结果表明:在CO_(2)注入阶段,煤层中甲烷迅速解吸;煤中气体吸附总量上升,煤基质膨胀效应增强,导致煤的孔隙体积降低。而转N_(2)注入后,由于N_(2)分压作用使得CH_(4)、CO_(2)吸附量呈现出不同程度的降低;当ωN_(2)/ωCO_(2)≤0.6时煤分子中气体总吸附量迅速降低,而当N_(2)饱和吸附后气体总吸附量保持稳定。煤层孔渗物性随着气体吸附总量呈现出迅速增大后趋于平缓的趋势。此外,ωN_(2)/ωCO_(2)>0.6后N_(2)吸附率迅速降低,这会使得产出气中CH_(4)纯度较低,导致后期提纯成本大大增加。因此,当ωN_(2)/ωCO_(2)=0.6左右时,CH_(4)解吸量为最大值,煤孔隙率较高,最有利于煤层气的开发。 展开更多
关键词 CO_(2)/N_(2)竞争吸附 分子模拟 煤层气 孔隙率 渗透率 延川南区块
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CaO-PAM在鲕状赤铁矿浮选废水处理中的混凝作用 被引量:3
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作者 张汉泉 姬志杰 +1 位作者 闵程 余洪 《矿产保护与利用》 2021年第1期73-78,共6页
鄂西高磷鲕状赤铁矿采用细磨-反浮选工艺可有效提铁降杂,实现铁的回收利用。但该工艺产生的废水浊度高,成分复杂,浮选废水回用困难。本研究对该反浮选废水进行了研究,发现废水pH值为9.6,散射浊度为95780 NTU,悬浮物浓度为1272 mg/L。采... 鄂西高磷鲕状赤铁矿采用细磨-反浮选工艺可有效提铁降杂,实现铁的回收利用。但该工艺产生的废水浊度高,成分复杂,浮选废水回用困难。本研究对该反浮选废水进行了研究,发现废水pH值为9.6,散射浊度为95780 NTU,悬浮物浓度为1272 mg/L。采用氧化钙(CaO)与聚丙烯酰胺(PAM)联用混凝沉淀法处理该废水,用量分别为350 mg/L和20 mg/L时,搅拌速率80 r/min搅拌10 min,处理后废水浊度降至19.9 NTU,出水率为80%~90%。通过Zeta电位和扫描电镜研究发现,CaO-PAM的加入,降低了悬浮微细粒间的静电斥力,发生了双电层吸附,通过架桥作用使微细粒发生了絮凝沉淀,从而降低了废水浊度及金属离子含量,满足了废水循环使用的要求,降低了废水外排造成的资源浪费和环境污染危害。 展开更多
关键词 鲕状赤铁矿 反浮选废水 聚丙烯酰胺 混凝沉淀法
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缺氧相关长链非编码RNA作为肝癌预后预测标志物的潜在价值 被引量:3
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作者 程敏 张静 +1 位作者 曹鹏博 周钢桥 《遗传》 CAS CSCD 北大核心 2022年第2期153-167,I0002-I0007,共21页
肝细胞癌(hepatocellular carcinoma,简称肝癌)是一种常见的恶性肿瘤。缺氧是肝癌等实体肿瘤的一个重要特征,同时也是诱导肿瘤恶性进展的重要因素。然而,肝癌缺氧相关的长链非编码RNA(long non-coding RNA,lncRNA)的鉴定及其在临床生存... 肝细胞癌(hepatocellular carcinoma,简称肝癌)是一种常见的恶性肿瘤。缺氧是肝癌等实体肿瘤的一个重要特征,同时也是诱导肿瘤恶性进展的重要因素。然而,肝癌缺氧相关的长链非编码RNA(long non-coding RNA,lncRNA)的鉴定及其在临床生存预后等方面的价值仍未得到系统的研究。本研究旨在通过肝癌转录组的整合分析鉴定肝癌缺氧相关的lncRNA,并评估其在肝癌预后中的价值。基于癌症基因组图谱(The Cancer Genome Atlas,TCGA)计划的肝癌转录组数据的整合分析,初步鉴定到233个缺氧相关的候选lncRNA。进一步筛选具有预后价值的候选者,基于其中12个缺氧相关lncRNA(AC012676.1、PRR7-AS1、AC020915.2、AC008622.2、AC026401.3、MAPKAPK5-AS1、MYG1-AS1、AC015908.3、AC009275.1、MIR210HG、CYTOR和SNHG3)建立了肝癌预后风险模型。Cox比例风险回归分析显示,基于该模型计算的缺氧风险评分作为肝癌患者新的独立预后预测指标,优于传统的临床病理因素。基因集富集分析显示,缺氧风险评分反映了细胞增殖相关通路的活化和脂代谢过程的失活。综上所述,本研究构建了一个基于缺氧相关lncRNA的风险评分模型,可以作为肝癌患者预后预测的候选指标,并初步提示了这些缺氧相关的lncRNA在肝癌防治中的重要作用。 展开更多
关键词 肝细胞癌 缺氧 长链非编码RNA 预后模型
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Effects of repetitive transcranial magnetic stimulation on cognitive function and cholinergic activity in the rat hippocampus after vascular dementia 被引量:37
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作者 Xiao-Qiao Zhang Li Li +2 位作者 Jiang-Tao Huo min cheng Lin-Hong Li 《Neural Regeneration Research》 SCIE CAS CSCD 2018年第8期1384-1389,共6页
Repetitive transcranial magnetic stimulation (rTMS) is a non-invasive treatment that can enhance the recovery of neurological function after stroke. Whether it can similarly promote the recovery of cognitive functio... Repetitive transcranial magnetic stimulation (rTMS) is a non-invasive treatment that can enhance the recovery of neurological function after stroke. Whether it can similarly promote the recovery of cognitive function after vascular dementia remains unknown, In this study, a rat model for vascular dementia was established by the two-vessel occlusion method. Two days after injury, 30 pulses of rTMS were ad- ministered to each cerebral hemisphere at a frequency of 0.5 Hz and a magnetic field intensity of 1,33 T. The Morris water maze test was used to evaluate learning and memory function. The Karnovsky-Roots method was performed to determine the density of cholinergic neurons in the hippocampal CA1 region. Immunohistochemical staining was used to determine the number of brain-derived neurotroph- ic factor (BDNF)-immunoreactive cells in the hippocampal CA1 region, rTMS treatment for 30 days significantly improved learning and memory function, increased acetylcholinesterase and choline acetyltransferase activity, increased the density of cholinergic neurons, and increased the number of BDNF-immunoreactive cells. These results indicate that rTMS can ameliorate learning and memory deficiencies in rats with vascular dementia, The mechanism through which this occurs might be related to the promotion of BDNF expression and subsequent restoration of cholinergic system activity in hippocampal CA 1 region. 展开更多
关键词 nerve regeneration cholinergic system neurotrophic factor hippocampal CA1 region learning and memory function repetitivetranscranial magnetic stimulation vascular dementia neural regeneration
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Stability of Cu-Mn bimetal catalysts based on different zeolites for NO_x removal from diesel engine exhaust 被引量:13
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作者 Shuang Zhao Liming Huang +3 位作者 Boqiong Jiang min cheng Jiawei Zhang Yijing Hu 《Chinese Journal of Catalysis》 SCIE EI CAS CSCD 北大核心 2018年第4期800-809,共10页
Cu–Mn bimetal catalysts were prepared to remove nitrogen oxides(NOx)from diesel engine exhaust at low temperatures.At a Cu/Mn ratio of 3:2,the NOx conversions at 200°C reached 65%and 90%on Cu–Mn/ZSM‐5 and Cu–... Cu–Mn bimetal catalysts were prepared to remove nitrogen oxides(NOx)from diesel engine exhaust at low temperatures.At a Cu/Mn ratio of 3:2,the NOx conversions at 200°C reached 65%and 90%on Cu–Mn/ZSM‐5 and Cu–Mn/SAPO‐34,respectively.After a hydrothermal treatment and reaction in the presence of C3H6,the activity of Cu–Mn/SAPO‐34 was more stable than that of Cu–Mn/ZSM‐5.No obvious variations in the crystal structure or dealumination were observed,whereas the physical structure was best maintained in Cu–Mn/SAPO‐34.The atomic concentration of Cu on the surface of Cu–Mn/SAPO‐34 was quite stable,and the consumption of octahedrally coordinated Cu2+could be recovered.Conversely,the proportion of octahedrally coordinated Cu2+on the surface of Cu–Mn/ZSM‐5 significantly decreased.Therefore,besides the structure,the redox cycle between Cu+and octahedrally coordinated Cu2+played an important role in the stability of the catalysts. 展开更多
关键词 Cu-Mn/SAPO-34 Cu-Mn/ZSM-5 Diesel engine exhaust Hydrothermal stability Resistance to hydrocarbons
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Valve-based compensation for controllability improvement of the energy-saving electrohydraulic flow matching system 被引量:10
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作者 min cheng Bing XU +1 位作者 Jun-hui ZHANG Ru-qi OING2 《Journal of Zhejiang University-Science A(Applied Physics & Engineering)》 SCIE EI CAS CSCD 2017年第6期430-442,共13页
The energy-saving electrohydraulic flow matching (EFM) system opens up an opportunity to minimize valve losses by fully opening the control valves, but the controllability is lost under overrunning load conditions. ... The energy-saving electrohydraulic flow matching (EFM) system opens up an opportunity to minimize valve losses by fully opening the control valves, but the controllability is lost under overrunning load conditions. To address this issue, this paper proposes a valve-based compensator to improve the controllability of the energy-saving EFM system. The valve-based compensator consists of a static compensator and a differential dynamic compensator based on load conditions. The energy effi- ciency, the stability performance, and the damping characteristic are analyzed under different control parameters. A parameter selection method is used to improve the efficiency, ensure the stability performance, and obtain good dynamic behavior. A test rig with a 2-t hydraulic excavator is built, and experimental tests are carried out to validate the proposed valve-based compensator. The experimental results indicate that the controllability of the EFM system is improved, and the characteristic of high energy efficiency is obtained by the proposed compensator. 展开更多
关键词 Compensation control Energy efficient Flow matching Mobile machinery
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Effect of thermal induced porosity on high-cycle fatigue and very high-cycle fatigue behaviors of hot-isostatic-pressed Ti-6Al-4V powder components 被引量:5
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作者 min cheng Zhengguan Lu +4 位作者 Jie Wu Ruipeng Guo Junwei Qiao Lei Xu Rui Yang 《Journal of Materials Science & Technology》 SCIE EI CAS CSCD 2022年第3期177-185,共9页
The present work reports the effect of thermal induced porosity(TIP)on the high-cycle fatigue(HCF)and very high-cycle fatigue(VHCF)behaviors of hot-isostatic-pressed(HIPed)Ti-6Al-4V alloy from gasatomized powder.The r... The present work reports the effect of thermal induced porosity(TIP)on the high-cycle fatigue(HCF)and very high-cycle fatigue(VHCF)behaviors of hot-isostatic-pressed(HIPed)Ti-6Al-4V alloy from gasatomized powder.The results show that the residual pores in the as-HIPed powder compacts present no obvious effect on the HCF life.The regrowth of the residual pores can be observed after solution heat treatment.The pore location ranks the most harmful for the fatigue life compared with the other initiating defects.The maximum stress intensity factors were calculated.The plastic zone size of fine granular area(FGA)is much less than the characteristic size of the microstructure,and the crucial size of the internal pores in this study is about 40μm.The failure types of fatigue specimens in the VHCF regime were classified,and the competition of different failure types was described based on the modified Poisson distribution. 展开更多
关键词 Titanium alloy Hot isostatic pressing Fatigue life Crack initiation type POROSITY
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Mesenchymal stem cells and mesenchymal stem cell-derived extracellular vesicles:Potential roles in rheumatic diseases 被引量:3
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作者 Jing-Han Yang Feng-Xia Liu +3 位作者 Jing-Hua Wang min cheng Shu-Feng Wang Dong-Hua Xu 《World Journal of Stem Cells》 SCIE CAS 2020年第7期688-705,共18页
BACKGROUND Mesenchymal stem cells(MSCs)have been widely investigated in rheumatic disease due to their immunomodulatory and regenerative properties.Recently,mounting studies have implicated the therapeutic potency of ... BACKGROUND Mesenchymal stem cells(MSCs)have been widely investigated in rheumatic disease due to their immunomodulatory and regenerative properties.Recently,mounting studies have implicated the therapeutic potency of MSCs mostly due to the bioactive factors they produce.Extracellular vesicles(EVs)derived from MSCs have been identified as a promising cell-free therapy due to low immunogenicity.Rheumatic disease,primarily including rheumatoid arthritis and osteoarthritis,is a group of diseases in which immune dysregulation and chronic progressive inflammation lead to irreversible joint damage.Targeting MSCs and MSC-derived EVs may be a more effective and promising therapeutic strategy for rheumatic diseases.AIM To evaluate the potential therapeutic effectiveness of MSCs and EVs generated from MSCs in rheumatic diseases.METHODS PubMed was searched for the relevant literature using corresponding search terms alone or in combination.Papers published in English language from January 1999 to February 2020 were considered.Preliminary screening of papers concerning analysis of"immunomodulatory function"or"regenerative function"by scrutinizing the titles and abstracts of the literature,excluded the papers not related to the subject of the article.Some other related studies were obtained by manually retrieving the reference lists of papers that comply with the selection criteria,and these studies were screened to meet the final selection and exclusion criteria.RESULTS Eighty-six papers were ultimately selected for analysis.After analysis of the literature,it was found that both MSCs and EVs generated from MSCs have great potential in multiple rheumatic diseases,such as rheumatoid arthritis and osteoarthritis,in repair and regeneration of tissues,inhibition of inflammatory response,and regulation of body immunity via promoting chondrogenesis,regulating innate and adaptive immune cells,and regulating the secretion of inflammatory factors.But EVs from MSCs exhibit much more advantages over MSCs,which may represent another promising cell-free restorative strategy.Targeting MSCs and MSC-derived EVs may be a more efficient treatment for patients with rheumatic diseases.CONCLUSION The enormous potential of MSCs and EVs from MSCs in immunomodulation and tissue regeneration offers a new idea for the treatment of rheumatism.However,more in-depth exploration is needed before their clinical application. 展开更多
关键词 Mesenchymal stem cell Extracellular vesicle AUTOIMMUNITY Inflammation Rheumatoid arthritis OSTEOARTHRITIS
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