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Influence of short chain ceramides and lipophilic penetration enhancers on the nano-structure of stratumcorneum model membranes studied using neutron diffraction

Annett SCHROETER, Tanja ENGELBRECHT, Reinhard H. H. NEUBERT

《化学科学与工程前沿（英文）》 2013年 第7卷 第1期   页码 29-36 doi: 10.1007/s11705-013-1302-0

摘要： Oriented stratum corneum model lipid membranes were used to study the influence of the short chain ceramides (CER)[NP] and [AP] as well as the impact of the lipophilic penetration enhancer molecules oleic acid (OA) and isopropyl myristate (IPM) on the lipid nanostructure. The influence of the enhancer molecules were studied using specifically deuterated OA and IPM and neutron diffraction. H NMR spectroscopy was used to study the impact of the ceramides’ degree of order within the stratum corneum model lipid membranes. It was found that CER[NP] forms two very stable phases with high resistance against temperature increase. Phase B showed unusual hydration behavior as no water uptake of this phase was observed. The H NMR spectroscopic measurements showed that CER[NP] based ternary model system had a higher state of lamellar order in comparison to CER[AP] based lipid matrix. The studies confirmed that the short chain ceramides, particularly CER[NP], have a very high impact on the integrity of the Stratum corneum lipid bilayers. The penetration enhancer OA has not influenced the repeat distance of the model membrane based on CER[AP], and was not able to induce a phase separation in the investigated lipid matrix. However, a disorder and a fluidisation of the model membranes were observed when OA was incorporated. IPM showed the same effect but two phases (assigned as phase A and B) appeared, when IPM was used as penetration enhancer and incorporated into the model membrane. Furthermore, two arrangements of IPM were identified in phase A using deuterated IPM. A model of the nanostructure of the Stratum corneum lipid membranes is presented.

关键词： nano-structure of the stratum corneum     ceramide     penetration enhancer     model membrane     neutron diffraction     2H NMR spectroscopy    

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Vibration analysis of nano-structure multilayered graphene sheets using modified strain gradient theory

Amir ALLAHBAKHSHI,Masih ALLAHBAKHSHI

《机械工程前沿（英文）》 2015年 第10卷 第2期   页码 187-197 doi: 10.1007/s11465-015-0339-9

摘要：

In this paper, for the first time, the modified strain gradient theory is used as a new size-dependent Kirchhoff micro-plate model to study the effect of interlayer van der Waals (vdW) force for the vibration analysis of multilayered graphene sheets (MLGSs). The model contains three material length scale parameters, which may effectively capture the size effect. The model can also degenerate into the modified couple stress plate model or the classical plate model, if two or all of the material length scale parameters are taken to be zero. After obtaining the governing equations based on modified strain gradient theory via principle of minimum potential energy, as only infinitesimal vibration is considered, the net pressure due to the vdW interaction is assumed to be linearly proportional to the deflection between two layers. To solve the governing equation subjected to the boundary conditions, the Fourier series is assumed for w=w(x, y). To show the accuracy of the formulations, present results in specific cases are compared with available results in literature and a good agreement can be seen. The results indicate that the present model can predict prominent natural frequency with the reduction of structural size, especially when the plate thickness is on the same order of the material length scale parameter.

关键词： graphene     van der Waals (vdW) force     modi- fied strain gradient elasticity theory     size effect parameter    

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Enhanced penetration strategies for transdermal delivery

Qiaofei Pan, Yinglin Yu, Dong Chen, Genlong Jiao, Xiaowen Liu

《化学科学与工程前沿（英文）》 2020年 第14卷 第3期   页码 378-388 doi: 10.1007/s11705-019-1913-1

摘要： Transdermal delivery offers several advantages in drug distribution, including convenience, painless administration, avoidance of first-pass metabolism, and ease of termination. However, the natural protective barriers of the skin, such as the stratum corneum, the topmost layer of skin, limit the systemic absorption of external therapeutics via transdermal delivery. Therefore, extensive application of transdermal delivery in medical treatment has been limited. Over the past few years, many formulation strategies and physical technologies, therefore, have been developed to enhance transdermal delivery. This review summarizes various formulation strategies proposed for transdermal delivery and their application in medical treatment.

关键词： transdermal delivery     stratum corneum     enhanced penetration     therapeutics    

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Displacement and force analyses of piles in the pile-caisson composite structure under eccentric inclinedloading considering different stratum features

《结构与土木工程前沿（英文）》 doi: 10.1007/s11709-023-0957-y

摘要： A novel anchorage for long-span suspension bridges, called pile-caisson composite structures, was recently proposed by the authors in an attempt to reduce the construction period and costs. This study aims to investigate the displacement and force behavior of piles in a pile-caisson composite structure under eccentric inclined loading considering different stratum features. To this end, both 1g model tests and three-dimensional numerical simulations were performed. Two groups of 1g model tests were used to validate the finite-element (FE) method. Parametric studies were then performed to investigate the effects of groundwater level, burial depth of the pile-caisson composite structure, and distribution of soil layers on the performance of the pile-caisson composite structure. The numerical analyses indicated that the influence of the groundwater level on the stability of the caisson was much greater than that of the piles. In addition, increasing the burial depth of the pile-caisson composite structure can assist in reducing the displacements and improving the stability of the pile-caisson composite structure. In addition, the distribution of soil layers can significantly affect the stability of the pile-caisson composite structure, especially the soil layer around the caisson.

关键词： composite structure     piles     foundation     suspension bridge     1g model test     finite-element analysis    

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Bicontinuous porous membranes with micro-nano composite structure using a facile atomization-assisted

《化学科学与工程前沿（英文）》 2022年 第16卷 第8期   页码 1268-1280 doi: 10.1007/s11705-022-2143-5

摘要： The micro-nano composite structure can endow separation membranes with special surface properties, but it often has the problems of inefficient preparation process and poor structural stability. In this work, a novel atomization-assisted nonsolvent induced phase separation method, which is also highly efficient and very simple, has been developed. By using this method, a bicontinuous porous microfiltration membrane with robust micro-nano composite structure was obtained via commercially available polymers of polyacrylonitrile and polyvinylpyrrolidone. The formation mechanism of the micro-nano composite structure was proposed. The microphase separation of polyacrylonitrile and polyvinylpyrrolidone components during the atomization pretreatment process and the hydrogen bonding between polyacrylonitrile and polyvinylpyrrolidone molecules should have resulted in the nano-protrusions on the membrane skeleton. The membrane exhibits superhydrophilicity in air and superoleophobicity underwater. The membrane can separate both surfactant-free and surfactant-stabilized oil-in-water emulsions with high separation efficiency and permeation flux. With excellent antifouling property and robust microstructure, the membrane can easily be recycled for long-term separation. Furthermore, the scale-up verification from laboratory preparation to continuous production has been achieved. The simple, efficient, cost-effective preparation method and excellent membrane properties indicate the great potential of the developed membranes in practical applications.

关键词： atomization     nonsolvent induced phase separation     bicontinuous porous structure     micro-nano composite structure     oil-water separation    

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β-Nickel hydroxide cathode material for nano-suspension redox flow batteries

Yue LI, Cheng HE, Elena V. TIMOFEEVA, Yujia DING, Javier PARRONDO, Carlo SEGRE, Vijay RAMANI

《能源前沿（英文）》 2017年 第11卷 第3期   页码 401-409 doi: 10.1007/s11708-017-0496-0

摘要： As part of an effort to build a prototype flow battery system using a nano-suspension containing β-Ni(OH) nanoparticles as the cathode material, nano-sized β-Ni(OH) particles with well-controlled particle size and morphology were synthesized via the one-step precipitation of a NiCl precursor. The composition and morphology of the nanoparticles were characterized by scanning electronic microscopy (SEM) and X-ray diffraction (XRD). The XRD patterns confirmed that β-Ni(OH) was successfully synthesized, while SEM results showed that the particle sizes range from 70 to 150 nm. To ensure that Ni(OH) could be employed in the nano-suspension flow battery, the electrochemical performance of the synthesized β-Ni(OH) was initially tested in pouch cells through charge/discharge cycling. The phase transformations occurring during charge/discharge were investigated using X-ray absorption spectroscopy to obtain the shift in the oxidation state of Ni (X-ray adsorption near edge structure, XANES) and the distances between Ni and surrounding atoms in charged and discharged states (extended X-ray absorption fine structure, EXAFS). XANES results indicated that the electrode in the discharged state was a mixture of phases because the edge position did not shift back completely. XAFS results further proved that the discharge capacity was provided by β-NiOOH and the ratio between β-Ni(OH) and g-NiOOH in the electrode in the discharged state was 71:29. Preliminary nano-suspension tests in a lab-scale cell were conducted to understand the behavior of the nano-suspension during charge/discharge cycling and to optimize the operating conditions.

关键词： nano-suspension flow battery     β-Ni(OH)2     scanning electronic microscopy (SEM)     X-ray diffraction (XRD)     X-ray adsorption near edge structure (XANES)     extended X-ray absorption fine structure (EXAFS)    

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Pore structure of cementitious material enhanced by graphitic nanomaterial: a critical review

S.A. GHAHARI, E. GHAFARI, L. ASSI

《结构与土木工程前沿（英文）》 2018年 第12卷 第1期   页码 137-147 doi: 10.1007/s11709-017-0431-9

摘要： Carbon nano tubes (CNT) has been introduced as an efficient nanomaterial in order to improve the mechanical and durability properties of concrete. The effect of CNT on the microstructures of cementitious materials has been widely reported. This paper combines a critical review on the effect of CNT on the pore and microstructure of cement composite with a discussion on the porosity measurement of pastes containing CNT using mercury intrusion porosimetry techniques (MIP). It was found that, surface treatment by H SO and HNO solution forms carboxyl acid groups on CNTs’ surfaces that lead to the improvement of reinforcement. In this scope, this review paper involves analyzing the effect of CNT on the microstructure and the pore structure of cementitious materials. The existing methods of measuring the porosity of cementitious material are reviewed, in particular, the contact angle measurement is discussed in detail in which the most effective parameters and possible errors of calculation is presented.

关键词： carbon nano tubes     microstructure     porosity     mercury intrusion porosimetry     cement composite    

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Experimental study on the stratum applicability and mechanisms of bubble–slurry for earth pressure balance

《结构与土木工程前沿（英文）》   页码 1387-1399 doi: 10.1007/s11709-023-0005-y

摘要： Soil conditioning is essential for addressing the stratum applicability problem of earth pressure balance (EPB) shields. Under high water pressures, EPB shields spew water and soil when excavating coarse-grained strata. Typically, foam combined with polymers and slurry is used to solve spewing. However, in current techniques, slurry, foam, and the other agents are mixed with soil separately, their synergistic effect is seldom realized. In this study, an anionic surfactant was used to foam in bentonite slurry to form bubble–slurry to maximize the synergy between bubbles and slurry. The slump, volume stability, and permeability test of bubble–slurry-conditioned sand was conducted to examine the conditioning effect, and the stratum applicability of bubble–slurry was determined from the perspective of permeability. It was found that the conditioning effect of bubble–slurry in coarse gravel soil was excellent and could expand the applicability of EPB shields. The main stabilization mechanism of bubble–slurry is that bentonite particles provide a space barrier for bubbles. And three seepage modes of bubble–slurry-conditioned sand were innovatively defined, and the occurrence conditions of the three seepage modes were analyzed according to the permeability coefficient of sand, initial dynamic shear force of bubble–slurry, and hydraulic gradient.

关键词： EPB shield     bubble–slurry     soil conditioning     stability     permeability    

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大尺度地层内的分层运动

许绍燮

《中国工程科学》 2006年 第8卷 第6期   页码 14-22

摘要：

报告了观察到大尺度地层内分层运动的新发现，以及大尺度层块活动的直接证据——大尺度地层垂向同步运动，其层块的尺度可大到数千公里洲际尺度。分析了我国超长周期（360～3000s）地震监测台站记录中的层块活动局域性高强颤振事件。发现格尔木台（2001年11月份）记录到的高强颤振事件与发生在其附近（2001.11.14）昆仑山口西M8.1大震有一定关系。这些信息对于探索地震预测，以及认识大地构造动力具有重要意义。

关键词： 大尺度地层内的分层运动     高强颤振事件     地震预测    

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Water-dispersible nano-pollutions reshape microbial metabolism in type-specific manners: A metabolic

《环境科学与工程前沿（英文）》 2022年 第16卷 第9期 doi: 10.1007/s11783-022-1548-1

摘要：

• Water-dispersible nano-pollutions exhibit type-specific toxic effects on E. coli.

关键词： Nano-toxicity     Nano-plastics     Quantum dots     Microbial metabolite     Metabolic dysregulation    

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Laboratory investigation of emulsified asphalt binder modified with wood-derived nano-cellulose and nano

Yunge WEI; Jiayu WANG; Ruoyu LI; Ling XU; Feipeng XIAO

《结构与土木工程前沿（英文）》 2022年 第16卷 第11期   页码 1474-1485 doi: 10.1007/s11709-022-0869-2

摘要： Emulsified asphalt is the primary material for preventive maintenance and cold-mix paving, but its low cohesive strength and poor mechanical properties limit its wide application, even with polymer modification. In this study, Styrene-Butadiene Rubber (SBR) emulsified asphalt was modified with nano-cellulose materials, namely nano paper-cellulose (NPC) and wood-derived nano-cellulose (WDC), to improve its properties. A novel preparation method of nano-cellulose solution was developed, including blending, ultrasonic stirring, and centrifugal treatment. Four types of nano-cellulose solution (0.5% NPC, 0.5%, 1.0%, and 1.5% WDC by weight of water) were selected. The microscopy analysis indicated that 0.5% WDC emulsion had a smaller particle size than 1.5% WDC emulsion. The rheology test indicated that WDC modified residue improved rutting resistance with the increased solution dosage due to the cross-linking effect, but its creep-and-recovery performance was worse than that of SBR emulsion residue. The NPC modified binder had a higher rutting factor than WDC modified binder at the same dosage after short-term aging. In addition, 1.0% WDC could be regarded as the optimal dosage in terms of fatigue and low-temperature performance. Furthermore, Fourier Transform Infrared Spectroscopy (FTIR) results showed that 0.5% NPC modified residue performed better in long-term aging resistance compared with 0.5%WDC modified asphalt.

关键词： nano-cellulose     emulsified asphalt binder     dispersion     rheological properties     Fourier transform infrared spectroscopy    

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Pd nano-catalyst supported on biowaste-derived porous nanofibrous carbon microspheres for efficient catalysis

《化学科学与工程前沿（英文）》 2023年 第17卷 第9期   页码 1289-1300 doi: 10.1007/s11705-023-2299-7

摘要： Environmental pollution caused by the presence of aromatic aldehydes and dyes in wastewater is a serious global concern. An effective strategy for the removal of these pollutants is their catalytic conversion, possibly to valuable compounds. Therefore, the design of efficient, stable and long-lifetime catalysts is a worthwhile research goal. Herein, we used nanofibrous carbon microspheres (NCM) derived from the carbohydrate chitin present in seafood waste, and characterized by interconnected nanofibrous networks and N/O-containing groups, as carriers for the manufacture of a highly dispersed, efficient and stable Pd nano-catalyst (mean diameter ca. 2.52 nm). Importantly, the carbonised chitin’s graphitized structure, defect presence and large surface area could promote the transport of electrons between NCM and Pd, thereby endowing NCM supported Pd catalyst with high catalytic activity. The NCM supported Pd catalyst was employed in the degradation of some representative dyes and the chemoselective hydrogenation of aromatic aldehydes; this species exhibited excellent catalytic activity and stability, as well as applicability to a broad range of aromatic aldehydes, suggesting its potential use in green industrial catalysis.

关键词： biowaste chitin     nanofibrous     palladium     nano-catalyst     catalysis    

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富水砂卵石地层中大直径泥水盾构同步注浆技术

张长强,翟志国,陈明娟,金仲祥

《中国工程科学》 2010年 第12卷 第12期   页码 75-78

摘要：

通过统计分析盾构掘进相关技术资料，综合考虑富水砂卵石地层中泥水盾构掘进参数、泥浆参数、盾构姿态、地层变形机理等信息，确定泥水盾构在砂卵石地层中掘进时，同步注浆主要技术参数间的经验公式，指导类似工程施工。

关键词： 砂卵石地层     泥水盾构     同步注浆     施工技术    

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Effects of different types of biochar on the properties and reactivity of nano zero-valent iron in soil

《环境科学与工程前沿（英文）》 2021年 第15卷 第5期 doi: 10.1007/s11783-021-1388-4

摘要：

• Biochar enhanced the mobility and stability of zero-valent iron nanoparticles.

关键词： Nano zero-valent iron     Biochar     BDE209     Transport     Soil    

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城市富水砂卵石地层大断面隧道浅埋暗挖工法研究

唐国荣,刘招伟,李建华

《中国工程科学》 2010年 第12卷 第12期   页码 98-102

摘要：

针对北京富水砂卵石地层大断面隧道地层稳定性差、工程周边环境复杂、对沉降控制要求高等诸多难题，在大断面隧道中采用CRD法、洞桩法进行施工，有效控制了工程结构、沿线及周围建筑物和地下管线的变形，确保了工程及周围环境的安全。

关键词： 砂卵石地层     大断面     CRD法     洞桩法     隧道施工    

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标题 作者 时间 类型 操作

Influence of short chain ceramides and lipophilic penetration enhancers on the nano-structure of stratumcorneum model membranes studied using neutron diffraction

Annett SCHROETER, Tanja ENGELBRECHT, Reinhard H. H. NEUBERT

期刊论文

Vibration analysis of nano-structure multilayered graphene sheets using modified strain gradient theory

Amir ALLAHBAKHSHI,Masih ALLAHBAKHSHI

期刊论文

Enhanced penetration strategies for transdermal delivery

Qiaofei Pan, Yinglin Yu, Dong Chen, Genlong Jiao, Xiaowen Liu

期刊论文

Displacement and force analyses of piles in the pile-caisson composite structure under eccentric inclinedloading considering different stratum features

期刊论文

Bicontinuous porous membranes with micro-nano composite structure using a facile atomization-assisted

期刊论文

β-Nickel hydroxide cathode material for nano-suspension redox flow batteries

Yue LI, Cheng HE, Elena V. TIMOFEEVA, Yujia DING, Javier PARRONDO, Carlo SEGRE, Vijay RAMANI

期刊论文

Pore structure of cementitious material enhanced by graphitic nanomaterial: a critical review

S.A. GHAHARI, E. GHAFARI, L. ASSI

期刊论文

Experimental study on the stratum applicability and mechanisms of bubble–slurry for earth pressure balance

期刊论文

大尺度地层内的分层运动

许绍燮

期刊论文

Water-dispersible nano-pollutions reshape microbial metabolism in type-specific manners: A metabolic

期刊论文

Laboratory investigation of emulsified asphalt binder modified with wood-derived nano-cellulose and nano

Yunge WEI; Jiayu WANG; Ruoyu LI; Ling XU; Feipeng XIAO

期刊论文

Pd nano-catalyst supported on biowaste-derived porous nanofibrous carbon microspheres for efficient catalysis

期刊论文

富水砂卵石地层中大直径泥水盾构同步注浆技术

张长强,翟志国,陈明娟,金仲祥

期刊论文

Effects of different types of biochar on the properties and reactivity of nano zero-valent iron in soil

期刊论文

城市富水砂卵石地层大断面隧道浅埋暗挖工法研究

唐国荣,刘招伟,李建华

期刊论文