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Study on the growth of platinum nanowires as cathode catalysts in proton exchange membrane fuel cells

Ruiqing Wang, Xiaolan Cao, Sheng Sui, Bing Li, Qingfeng Li

《化学科学与工程前沿（英文）》 2022年 第16卷 第3期   页码 364-375 doi: 10.1007/s11705-021-2052-z

摘要： The platinum nanowires have been verified to be a promising catalyst to promote the performance of proton exchange membrane fuel cells. In this paper, accurately controlled growth of nanowires in a carbon matrix is achieved for reducing Pt loading. The effects of formic acid concentration and reaction temperature on the morphology and size of the Pt nanowires, as well as their electrochemical performances in a single cell, are investigated. The results showed that the increase in the formic acid concentration results in a volcano trend with the length of Pt nanowires. With increasing reduction temperature, the diameter of Pt nanowires increases while Pt particles evolve from one-dimensional to zero-dimensional up to 40 °C. A mechanism of the Pt nanowires growth is proposed. The optimized Pt nanowires electrode exhibits a power density (based on electrochemical active surface area) 79% higher than conventional Pt/C one. The control strategy obtained contributes to the design and control of novel nanostructures in nano-synthesis and catalyst applications.

关键词： Pt nanowires     morphology     structure control     in situ growth mechanism     proton exchange membrane fuel cells    

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Nucleation and growth mechanism of cefodizime sodium at different solvent compositions

Xinwei ZHANG, Shudong ZHANG, Xiaodan SUN, Zequn YIN, Quanjie LIU, Xiwen ZHANG, Qiuxiang YIN

《化学科学与工程前沿（英文）》 2013年 第7卷 第4期   页码 490-495 doi: 10.1007/s11705-013-1350-5

摘要： The induction time of cefodizime sodium was measured in ethanol-water at different solvent compositions by the laser technology measurement. The results indicate that the solvent composition played an important role in the supersaturation and the nucleation process of cefodizime sodium solution. According to the modified classical nucleation theory, the nucleation and growth mechanism were identified. The correlation results show that heterogeneous nucleation dominated the nucleation process at lower supersaturation, where homogeneous nucleation is the most important mechanism at higher supersaturation. Based on the correlated results, the 2D mediated growth mechanism had the highest correlation coefficients ( ), so this mechanism was selected as the proper growth mechanism for cefodizime sodium.

关键词： cefodizime sodium     induction time     primary nucleation     growth mechanism    

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>In situ growth of phosphorized ZIF-67-derived amorphous CoP/Cu2O@CF electrocatalyst

《化学科学与工程前沿（英文）》 2023年 第17卷 第10期   页码 1430-1439 doi: 10.1007/s11705-023-2320-1

摘要： Transition metal phosphides have been extensively studied for catalytic applications in water splitting. Herein, we report an in situ phosphorization of zeolitic imidazole frameworks (ZIF-67) to generate amorphous cobalt phosphide/ZIF-67 heterojunction on a self-supporting copper foam (CF) substrate with excellent performance for hydrogen evolution reaction (HER). The needle-leaf like copper hydroxide was anchored on CF surface, which acted as implantation to grow ZIF-67. The intermediate product was phosphorized to obtain final electrocatalyst (CoP/Cu2O@CF) with uniform particle size, exhibiting a rhombic dodecahedron structure with wrinkles on the surface. The electrochemical measurement proved that CoP/Cu2O@CF catalyst exhibited excellent HER activity and long-term stability in 1.0 mol·L–1 KOH solution. The overpotential was only 62 mV with the Tafel slope of 83 mV·dec–1 at a current density of 10 mA·cm–2, with a large electrochemical active surface area. It also showed competitive performance at large current which indicated the potential application to industrial water electrolysis to produce hydrogen. First-principle calculations illustrated that benefit from the construction of CoP/ZIF-67 heterojunction, the d-band center of CoP downshifted after bonding with ZIF-67 and the Gibbs free energy (ΔGH*) changed from –0.18 to –0.11 eV, confirming both decrease in overpotential and excellent HER activity. This work illustrates the efficient HER activity of CoP/Cu2O@CF catalyst, which will act as a potential candidate for precious metal electrocatalysts.

关键词： CoP/Cu2O@CF     electrocatalyst     phosphorization     HER     DFT    

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Mechanism of vascular endothelial growth factor on the prevention of restenosis after angioplasty

Qigong LIU, Honglian ZHOU, Yan ZENG, Shan YE, Jiani LIU, Zaiying LU

《医学前沿（英文）》 2009年 第3卷 第2期   页码 177-180 doi: 10.1007/s11684-009-0021-x

摘要： To evaluate the mechanism of vascular endothelial growth factor (VEGF) on the prevention of restenosis after angioplasty, the recombinant adenovirus vector containing hVEGF cDNA was constructed and transfected into vascular smooth muscle cells (VSMC) . The conditioned medium containing VEGF was collected 72 h after the infection. Then, the VSMC and human umbilical vein endothelial cells (HUVEC) were divided into control group, H O -treated group and H O +VEGF-treated group to observe the proliferation and apoptosis by water soluble tetrazolium (WST-1) method, nick end labeling (TUNEL) and flow cytometry (FCM). Compared with the control and H O +VEGF-treated groups, the absorbance ( ) value of HUVEC was decreased, and apoptosis of HUVEC was significantly increased in H O -treated group. The changes of value and apoptosis of VSMC were contrary to those of HUVEC. H O could stimulate the proliferation of VSMC and induce the apoptosis of HUVEC, inhibit the proliferation of HUVEC and the apoptosis of VSMC and induce restenosis. VEGF could inhibit the effect of H O on HUVEC and VSMC and prevent restenosis. These results offered further theoretical evidence for VEGF on the prevention of restenosis after angioplasty.

关键词： vascular endothelial growth factors     restenosis     reactive oxygen species     endothelial cells     vascular smooth muscle cell    

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钢产量增长机制的解析及2000—2007年我国钢产量增长过快原因的探索

陆钟武,岳强

《中国工程科学》 2010年 第12卷 第6期   页码 4-11

摘要：

分两步解析钢产量的增长机制，首先在若干假设条件下提出了钢产量增长的基准模式，其主要特点是钢产量与GDP同步增长，分析了基准模式下的钢产量、在役钢量、GDP以及它们的年增长率；然后讨论偏离基准模式的各种可能性，及其对钢产量增速的影响。在此基础上得到了钢产量年增长率的基本计算式。分析了偏离基准模式对单位GDP钢产量的影响。在对钢产量增长机制进行解析的基础上，广泛联系全社会发生的各种现象，提出使我国钢产量增速远远超过GDP增速的16种现象，提出在宏观调控工作中，要区别对待这些现象。从中、日、美三国单位GDP钢产量数据对比可见，我国降低单位GDP钢产量的空间很大。文章为我国钢铁行业的宏观调控提供了新思路。

关键词： 钢产量     在役钢量     GDP     年增长率     机制     基准模式    

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生物质制备纳米零价铁生物炭的铁相转移和原位还原机制 Article

卓胜男, 任宏宇, 谢国俊, 邢德峰, 刘冰峰

《工程（英文）》 2023年 第21卷 第2期   页码 124-134 doi: 10.1016/j.eng.2021.07.012

摘要：

纳米零价铁生物炭（nZVI-BC）作为一种由废弃生物质制备的环境友好型材料，可有效解决生物质转化和环境污染问题。然而，复杂的生物质/生物炭改性过程阻碍了它们的进一步生产和应用。在本研究中，一种绿色溶剂聚乙二醇400（PEG400）被引入FeCl3⋅6H2O改性水稻秸秆（RS）的反应体系中，改性后的RS通过一步热解法被转化为nZVI-BC。PEG400 的添加促进了铁离子的水解并改善了RS的表面结构，有利于Fe2O3附着到RS表面。在60 ℃、80 ℃、100 ℃和0.5 h 的改性条件下，RS中木质素组分损失不多，有利于高温热解过程中碳骨架的形成。Fe2O3在热解产生的还原气体和无定形碳的帮助下被还原，最终形成nZVI-BC。将该方法制备的nZVI-BC 用于染料刚果红的催化高级氧化去除，结果表明，nZVI-BC 具有快速的吸附能力（5 min 时吸附效果为70.6%）和高效的催化降解能力（60 min 时催化降解90%）。本研究为nZVI-BC的制备提供了一种新的策略，为其规模化生产和应用奠定了基础。

关键词： 生物质转化     纳米零价铁生物炭     原位热解     铁相转移    

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Room temperature preparation of hydrazine-linked covalent organic frameworks coated capillaries for separation and determination of polycyclic aromatic hydrocarbons

《化学科学与工程前沿（英文）》 2023年 第17卷 第5期   页码 548-556 doi: 10.1007/s11705-022-2252-1

摘要： Covalent organic frameworks (COFs) have been increasingly used in capillary electrochromatography due to their excellent characteristics. In this work, hydrazine-linked TFPB-DHzDS (TFPB: 1,3,5-tris(4-formylphenyl)benzene; DHzDS: 2,5-bis(3-(ethylthio)propoxy)terephthalohydrazide) was first synthesized by a simpler and easier method at room temperature and introduced into capillary electrochromatography as coating material. The TFPB-DHzDS coated capillaries were prepared by an in-situ growth process at room temperature. After optimizing the coating concentration and experimental conditions of capillary electrochromatography, baseline separation of two groups of polycyclic aromatic hydrocarbons was achieved based on the TFPB-DHzDS coated capillary. And the established method was used successfully to determine PAHs in natural water and soil samples. The spiked recoveries of polycyclic aromatic hydrocarbons in these samples ranged from 90.01% to 111.0%, indicating that the method is reliable and could detect polycyclic aromatic hydrocarbons in natural samples. Finally, molecular simulation was applied to study and visualize the interaction between the analytes and coating COF materials to investigate the molecular level separation mechanism further.

关键词： hydrazine-linked TFPB-DHzDS     in-situ growth method     open-tubular capillary electrochromatography     molecular simulations    

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Development and application of ex-situ presulfurization technology for hydrotreating catalysts in China

Yulan GAO, Xiangchen FANG, Zhenmin CHENG

《化学科学与工程前沿（英文）》 2011年 第5卷 第3期   页码 287-296 doi: 10.1007/s11705-010-0529-2

摘要： The development and application of ex-situ presulfurization (EPRES) technology for hydrotreating catalysts has been reviewed in the present article. The studies in laboratory scale and commercial practice indicated that the adoption of the EPRES catalyst in industrial application can significantly enhance the degree of presulfurization of metal oxide components, shorten the start-up period, and effectively reduce the environmental impact as well as the danger of start-up procedure in industrial hydrotreating unit. This catalyst has been proved to be versatile for different types of hydrogenation reactions. Different types of active site models are also discussed for better understanding the nature of presulfurized catalysts.

关键词： ex-situ presulfurization     in situ presulfurization     hydrotreating catalyst     sulfur utilization ratio    

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A novel six-legged walking machine tool for

Jimu LIU, Yuan TIAN, Feng GAO

《机械工程前沿（英文）》 2020年 第15卷 第3期   页码 351-364 doi: 10.1007/s11465-020-0594-2

摘要： The manufacture and maintenance of large parts in ships, trains, aircrafts, and so on create an increasing demand for mobile machine tools to perform operations. However, few mobile robots can accommodate the complex environment of industrial plants while performing machining tasks. This study proposes a novel six-legged walking machine tool consisting of a legged mobile robot and a portable parallel kinematic machine tool. The kinematic model of the entire system is presented, and the workspace of different components, including a leg, the body, and the head, is analyzed. A hierarchical motion planning scheme is proposed to take advantage of the large workspace of the legged mobile platform and the high precision of the parallel machine tool. The repeatability of the head motion, body motion, and walking distance is evaluated through experiments, which is 0.11, 1.0, and 3.4 mm, respectively. Finally, an application scenario is shown in which the walking machine tool steps successfully over a 250 mm-high obstacle and drills a hole in an aluminum plate. The experiments prove the rationality of the hierarchical motion planning scheme and demonstrate the extensive potential of the walking machine tool for operations on large parts.

关键词： legged robot     parallel mechanism     mobile machine tool     in-situ machining    

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Photosynthesis and related metabolic mechanism of promoted rice (Oryza sativa L.) growth by TiO2 nanoparticles

Yingdan Zhang, Na Liu, Wei Wang, Jianteng Sun, Lizhong Zhu

《环境科学与工程前沿（英文）》 2020年 第14卷 第6期 doi: 10.1007/s11783-020-1282-5

摘要： Abstract • The rice growth was promoted by nano-TiO2 of 0.1–100 mg/L. • Nano-TiO2 enhanced the energy storage in photosynthesis. • Nano-TiO2 reduced energy consumption in carbohydrate metabolism and TCA cycle. Titanium dioxide nanoparticle (nano-TiO2), as an excellent UV absorbent and photo-catalyst, has been widely applied in modern industry, thus inevitably discharged into environment. We proposed that nano-TiO2 in soil can promote crop yield through photosynthetic and metabolic disturbance, therefore, we investigated the effects of nano-TiO2 exposure on related physiologic-biochemical properties of rice (Oryza sativa L.). Results showed that rice biomass was increased >30% at every applied dosage (0.1–100 mg/L) of nano-TiO2. The actual photosynthetic rate (Y(II)) significantly increased by 10.0% and 17.2% in the treatments of 10 and 100 mg/L respectively, indicating an increased energy production from photosynthesis. Besides, non-photochemical quenching (Y(NPQ)) significantly decreased by 19.8%–26.0% of the control in all treatments respectively, representing a decline in heat dissipation. Detailed metabolism fingerprinting further revealed that a fortified transformation of monosaccharides (D-fructose, D-galactose, and D-talose) to disaccharides (D-cellobiose, and D-lactose) was accompanied with a weakened citric acid cycle, confirming the decrease of energy consumption in metabolism. All these results elucidated that nano-TiO2 promoted rice growth through the upregulation of energy storage in photosynthesis and the downregulation of energy consumption in metabolism. This study provides a mechanistic understanding of the stress-response hormesis of rice after exposure to nano-TiO2, and provides worthy information on the potential application and risk of nanomaterials in agricultural production.

关键词： Nano-TiO2     Rice     Photosynthesis     Metabolomics     Energy storage    

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Polyolefin-nanocomposites with special properties by in-situ polymerization

Walter Kaminsky

《化学科学与工程前沿（英文）》 2018年 第12卷 第3期   页码 555-563 doi: 10.1007/s11705-018-1715-x

摘要：

Exceptionally strong polyolefin nanocomposites are synthesized by in-situ polymerization using soluble metallocene/methylaluminoxane (MAO) as catalysts in a two-step process. First, the soluble metallocene/MAO or other single site catalysts are absorbed on the surface of the nanofillers. Then by addition of ethene or propene, a polyolefin film is formed, covering the nanoparticles, layered silicates, or fibers. The resulting polyethylene and polypropylene nanocomposites are characterized by better physical and chemical properties such as stiffness, gas barrier properties, degradation temperatures, and crystallization rates. They show better mechanical properties than materials produced by mechanical blending. The thickness of the polyolefin can be controlled by the pressure of ethene or propene and by the polymerization time. Carbon fibers and carbon nanotubes are covered with isotactic or syndiotactic polypropylene. Because of the hydrophobic character of the carbon surface, the polymer is drawn on the fiber. This leads to a reinforced combined polymer with special properties. The crystallization temperature is 10 °C higher and therefore the crystallization rate up to 20 times faster than that of pure syndiotactic polypropylene. The form stability increases by 100% if 3 wt-% of carbon nanotubes are incorporated.

关键词： polyolefin nanocomposites     metallocenes     methylaluminoxane    

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Economic Growth Model Based on Six Basic Factors of Production—Xu Growth Rate Equation

Shou-bo Xu,Zong-yuan Huang

《工程管理前沿（英文）》 2014年 第1卷 第2期   页码 160-175 doi: 10.15302/J-FEM-2014024

摘要： This paper proposes an economic growth model based on the Six Basic Factors of Production and Xu Growth Rate Equation for the first time, which fills-in the deficits of the New Classical Economic Growth Model based on the Solow Model. The empirical analysis indicates that over the past three decades, the consumption of six basic factors of production had complicated relations with economic growth. In some years, the consumption rate of the basic factors of production was meager, but the economy witnessed relatively rocketing growth rate; in some years, the factors of production consumption rate was very high, but the economy growth rate slowed down. In general, economy grows at the expenses of huge consumption of four factors. There is an obvious characteristic of huge input and low efficiency. The average contribution rate of technological advance peaks in the middle, while it drops down at two ends. Noticeably, since 2004, the technology contribution rate generally shows a downward trend, reasons of which should be explored systematically in aspects like economic policy and industry structure with a view to boost further transformation of the macro-economy scientific growth model.

关键词： six basic factors of production     economic growth model     Xu Growth Rate Equation    

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Clinical evaluation of recombinant human growth hormone injection in children with growth hormone deficiency

Ling HOU, Xiaoping LUO, Minlian DU, Huamei MA, Chunxiu GONG, Yuchuan LI, Shuixian SHEN, Zhuhui ZHAO, Li LIANG, Guanping DONG, Chaoying YAN, Hongwei DU

《医学前沿（英文）》 2009年 第3卷 第2期   页码 171-176 doi: 10.1007/s11684-009-0027-4

摘要： Recombinant human growth hormone (rhGH) has been widely used in the clinical treatment of growth hormone deficiency. To simplify the injection process and increase drug compliance, application of the GH injection has become a new treatment plan in recent years. The purpose of the current study was to evaluate the efficacy and safety of rhGH injection for the treatment of growth hormone deficiency (GHD) in children in China. In a nationwide, noncomparative, prospective, randomized, open trial, 31 children with confirmed complete GHD received subcutaneous injection of rhGH at 0.25 mg/kg·wk (0.107 IU/kg·d). The injection was given daily and the total weekly amount was separated into 6-7 injections. The patients were followed up at 3-month intervals and the treatment duration was 12 months. The height (HT), annual growth velocity (GV), mean height standard deviation score (HT SDS), blood serum insulin-like growth factor I (IGF-I), insulin-like growth factor binding protein 3 (IGFBP-3), and bone maturity before and after treatment were compared, and the safety of the treatment was analyzed. The mean HT, GV, and HT SDS were increased from 109.0±14 cm, 2.7±0.9 cm/yr, and -4.62±1.46 at baseline to 121.8±13.4 cm, 12.9±3.3 cm/yr, and -2.47±1.86 after 12 months of treatment, respectively ( <0.001). At the same time, blood IGF-I and IGFBP-3 were increased significantly [41.27±64.43 μg/L 159.21±167.92 μg/L and 1540.00±1325.11 mg/L 3533.93±1413.82 mg/L, respectively ( <0.001)]. The bone age assessments performed 6 and 12 months after the treatment showed that no advanced bone maturation was noted. No serious adverse events occurred during the treatment, and the drug-related adverse events were mainly decreased thyroid function. We conclude that rhGH injection is a safe and effective drug for treatment of growth hormone deficiency in children.

关键词： recombinant human growth hormone     injection     growth hormone deficiency    

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Copper fractal growth during recycling from waste printed circuit boards by slurry electrolysis

《环境科学与工程前沿（英文）》 2021年 第15卷 第6期 doi: 10.1007/s11783-021-1405-7

摘要：

• Copper fractal growth was observed during WPCBs recycling by slurry electrolysis.

关键词： Dendritic copper     Fractal growth     WPCBs     Slurry electrolysis    

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Growth and abscisic acid responses of

Yue LI, Liqiang WAN, Yufei WANG, Xianglin LI

《农业科学与工程前沿（英文）》 2018年 第5卷 第1期   页码 80-86 doi: 10.15302/J-FASE-2017199

摘要： A pot experiment was conducted in a greenhouse with three alfalfa ( ) cultivars, Aohan, Zhongmu No.1 and Sanditi, to examine the morphological and physiological responses of alfalfa to water stress. The response of alfalfa to water stress at different growth stages was generally similar, but varied among cultivars. At the branching, flowering and podding stages, the shoot biomasses of Aohan and Zhongmu No.1 were greatly affected by, and responded quickly to, water stress. The shoot biomass of Sanditi was not affected by mild water stress, but had a slight response to moderate and severe water stress. The root/shoot ratios in Aohan and Zhongmu No.1 were more sensitive to water stress than in Sanditi, with the root/shoot ratio in Aohan increasing most significantly. At flowering, the root/shoot ratio was the highest and the effect of water stress the greatest. The abscisic acid (ABA) concentration in the roots of Aohan and Zhongmu No.1 increased under water stress, while in Sanditi there was only a slight or delayed response of ABA concentration.

关键词： abscisic acid     alfalfa     drought response     growth stage     water deficit    

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标题 作者 时间 类型 操作

Study on the growth of platinum nanowires as cathode catalysts in proton exchange membrane fuel cells

Ruiqing Wang, Xiaolan Cao, Sheng Sui, Bing Li, Qingfeng Li

期刊论文

Nucleation and growth mechanism of cefodizime sodium at different solvent compositions

Xinwei ZHANG, Shudong ZHANG, Xiaodan SUN, Zequn YIN, Quanjie LIU, Xiwen ZHANG, Qiuxiang YIN

期刊论文

>In situ growth of phosphorized ZIF-67-derived amorphous CoP/Cu2O@CF electrocatalyst

期刊论文

Mechanism of vascular endothelial growth factor on the prevention of restenosis after angioplasty

Qigong LIU, Honglian ZHOU, Yan ZENG, Shan YE, Jiani LIU, Zaiying LU

期刊论文

钢产量增长机制的解析及2000—2007年我国钢产量增长过快原因的探索

陆钟武,岳强

期刊论文

生物质制备纳米零价铁生物炭的铁相转移和原位还原机制

卓胜男, 任宏宇, 谢国俊, 邢德峰, 刘冰峰

期刊论文

Room temperature preparation of hydrazine-linked covalent organic frameworks coated capillaries for separation and determination of polycyclic aromatic hydrocarbons

期刊论文

Development and application of ex-situ presulfurization technology for hydrotreating catalysts in China

Yulan GAO, Xiangchen FANG, Zhenmin CHENG

期刊论文

A novel six-legged walking machine tool for

Jimu LIU, Yuan TIAN, Feng GAO

期刊论文

Photosynthesis and related metabolic mechanism of promoted rice (Oryza sativa L.) growth by TiO2 nanoparticles

Yingdan Zhang, Na Liu, Wei Wang, Jianteng Sun, Lizhong Zhu

期刊论文

Polyolefin-nanocomposites with special properties by in-situ polymerization

Walter Kaminsky

期刊论文

Economic Growth Model Based on Six Basic Factors of Production—Xu Growth Rate Equation

Shou-bo Xu,Zong-yuan Huang

期刊论文

Clinical evaluation of recombinant human growth hormone injection in children with growth hormone deficiency

Ling HOU, Xiaoping LUO, Minlian DU, Huamei MA, Chunxiu GONG, Yuchuan LI, Shuixian SHEN, Zhuhui ZHAO, Li LIANG, Guanping DONG, Chaoying YAN, Hongwei DU

期刊论文

Copper fractal growth during recycling from waste printed circuit boards by slurry electrolysis

期刊论文

Growth and abscisic acid responses of

Yue LI, Liqiang WAN, Yufei WANG, Xianglin LI

期刊论文