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1.
Aging (Albany NY) ; 162024 May 14.
Article in English | MEDLINE | ID: mdl-38747738

ABSTRACT

OBJECTIVE: This study examines SHP2's influence on the STAT3/STAT6 pathway in tumor-associated macrophages (TAMs) and its impact on lung adenocarcinoma proliferation and metastasis. METHODS: Lung cancer A549 and NCI-H1688 cell lines were subcutaneously injected into nude mice. Macrophages were isolated using flow cytometry and analyzed for CD163, CD206, and Arginase-1 levels via western blot. Similarly, the effect on THP1 cell-associated proteins was assessed. The impact on A549 and NCI-H1688 cell migration, invasion, and proliferation was evaluated through wound healing, Transwell assays, and CCK8. RESULTS: Compared to controls, the sh-RNA SHP2 group showed increased tumor volume and higher expression levels of CD163, CD206, Arginase-1, p-STAT3, p-STAT6, IL-4, IL-10, and various cathepsins in macrophages and THP1 cells. However, p-STAT1 and p-STAT5 levels remained unchanged. The sh-RNA SHP2 group also demonstrated enhanced migration, invasion, and proliferation in both cell lines. CONCLUSIONS: SHP2 negatively affects the STAT3/STAT6 pathway in TAMs, promoting M2 polarization and cathepsin secretion, which enhances lung adenocarcinoma cell proliferation and metastasis.

2.
Nanotechnology ; 35(29)2024 Apr 30.
Article in English | MEDLINE | ID: mdl-38569481

ABSTRACT

Conductive Poly(3,4-ethylenedioxythiophene):poly(styrenesulfonate) (PEDOT:PSS) has been extensively used as non-metallic electrodes. However, the relatively low electrical conductivity of pristine PEDOT:PSS film restricts its further application. Although doping high content conductive filler or increasing the film thickness are effective for enhancing the electrical property, the transparency is sacrificed, which limits the application of PEDOT:PSS films. In this study, preparing PEDOT:PSS composite film with highly conductive and transparent property was the primary purpose. To achieve this goal, single-walled carbon nanotubes (SWCNTs) and dimethyl sulfoxide (DMSO) was chosen to composite with PEDOT:PSS. The spin-coated SWCNT/PEDOT:PSS composite film exhibited excellent electrical conductivity and transparency. The electrical conductivity of composite film with desired transmittance property (78%) reached the highest value (1060.96 S cm-1) at the SWCNTs content was 6 wt%. Under the modification process applied in this work, the non-conductive PSS was partially removed by incorporated DMSO and SWCNTs. Then, the molecular chains of PEDOT stretched and adsorbed onto the surface of SWCNTs, forming a highly efficient three-dimensional conductive structure, which contributed to the enhancement of electrical conductivity and transparency. Additionally, the spin-coating process allowed for the reduction of film thickness, ensuring better transparency. This research contributed to expanding the further applications of PEDOT:PSS films in high-performance transparent film electrodes.

3.
J Phys Condens Matter ; 36(25)2024 Mar 27.
Article in English | MEDLINE | ID: mdl-38484393

ABSTRACT

The van der Waals (vdW) heterostructures of Z-scheme PbI2/g-C3N4with an indirect bandgap have gained much attention in recent years due to their unique properties and potential applications in various fields. However, the optoelectronic characteristics and strain-modulated effects are not yet fully understood. By considering this, six stacking models of PbI2/g-C3N4are proposed and the stablest structure is selected for further investigation. The uniaxial and biaxial strains (-10%-10%) regulated band arrangement, charge distribution, optical absorption in the framework of density functional theory are systematically explored. The compressive uniaxial strain of -8.55% changes the band type from II→I, and the biaxial strains of -7.12%, -5.25%, 8.91% change the band type in a way of II→I→II→I, acting like the 'band-pass filter'. The uniaxial strains except -10% compressive strain, and the -6%, -4%, 2%, 4%, 10% biaxial strains will enhance the light absorption of PbI2/g-C3N4. The exerted strains on PbI2/g-C3N4generate different power conversion efficiency (ηPCE) values ranging from 3.64% to 25.61%, and the maximumηPCEis generated by -6% biaxial strain. The results of this study will pave the way for the development of new electronic and optoelectronic materials with customized properties in photocatalytic field and optoelectronic devices.

4.
PLoS One ; 19(3): e0298683, 2024.
Article in English | MEDLINE | ID: mdl-38483882

ABSTRACT

Urbanization leads to dramatic changes in habitat quality, which significantly affects population health. Research on the coupling coordination relationship between new urbanization and health production efficiency is conducive to improving residents' well-being and urban sustainable development. In this article, we adopted the super-efficient SBM model and entropy value method separately to evaluate the spatiotemporal variation characteristics of health production efficiency and new urbanization in China. Then, we used the coupling coordination degree model to investigate the interactive coercing relationship between new urbanization and health production efficiency. Finally, the panel Tobit model is used to analyze the factors influencing the coupled coordination of the two systems. The results showed that the new urbanization levels of 31 provinces in China have all steadily increased from 2003 to 2018. Health production efficiency exhibited a fluctuating but increasing trend, and its regional differences are gradually narrowing. Health production efficiency and new urbanization have developed in a more coordinated direction, with a spatial pattern of "high in the southeast and low in the northwest." Meanwhile, the relative development characteristics between the two systems have constantly changed, from the new urbanization lagged type to the two systems synchronized type and the health production efficiency lagged type. Population density, economic development level, government financial investment, and government health investment positively impact the coupling coordination degree of the two systems. In comparison, individual health investment harms the harmonization of the two systems.


Subject(s)
Ecosystem , Urbanization , Economic Development , Efficiency , China , Cities
5.
Analyst ; 148(23): 5889-5895, 2023 Nov 20.
Article in English | MEDLINE | ID: mdl-37927227

ABSTRACT

Three copper iodide coordination polymer (CuI-p-DPA) isomers were prepared from the fluorescent organic ligand p-DPA and cuprous iodide (CuI) under different solvothermal conditions, which exhibited quenched fluorescence behaviors after forming coordination polymers (CPs). These CuI-p-DPA isomers showed discrepant fluorescence responses to thiophanate-methyl (TM). Among these CuI-p-DPA isomers, α-CuI-p-DPA exhibited the maximum fluorescence enhancement after its incubation with TM in aqueous solution. The fluorescence enhancement mechanism was that TM competed with the ligand p-DPA to coordinate with CuI clusters, and then α-CuI-p-DPA released p-DPA into the solution and induced fluorescence enhancement. The present detection method possesses the advantages of good selectivity, high sensitivity, short response time, and strong anti-interference ability with a linear range of 0.5-100 µM and a detection limit of 0.01 µM. This study not only reveals that the spatial structures of CPs play an important role in the fluorescence response ability, but also provide a new fluorescence signal-on analysis method to rapidly and sensitively determine the pesticide residue for TM.

6.
Front Public Health ; 11: 1099175, 2023.
Article in English | MEDLINE | ID: mdl-37497032

ABSTRACT

Objective: To understand the prevalence among underground coal miners of musculoskeletal disorders (MSDs), analyze the risk factors affecting MSDs, and develop and validate a risk prediction model for the development of MSDs. Materials and methods: MSD questionnaires were used to investigate the prevalence of work-related musculoskeletal disorders among 860 underground coal miners in Xinjiang. The Chinese versions of the Effort-Reward Imbalance Questionnaire (ERI), the Burnout Scale (MBI), and the Self-Rating Depression Inventory (SDS) were used to investigate the occupational mental health status of underground coal miners. The R4.1.3 software cart installation package was applied to randomly divide the study subjects into a 1:1 training set and validation set, screen independent predictors using single- and multi-factor regression analysis, and draw personalized nomogram graph prediction models based on regression coefficients. Subject work characteristic (ROC) curves, calibration (Calibrate) curves, and decision curves (DCA) were used to analyze the predictive value of each variable on MSDs and the net benefit. Results: (1) The prevalence of MSDs was 55.3%, 51.2%, and 41.9% since joining the workforce, in the past year, and in the past week, respectively; the highest prevalence was in the lower back (45.8% vs. 38.8% vs. 33.7%) and the lowest prevalence was in the hips and buttocks (13.3% vs. 11.4% vs. 9.1%) under different periods. (2) Underground coal miners: the mean total scores of occupational stress, burnout, and depression were 1.55 ± 0.64, 51.52 ± 11.53, and 13.83 ± 14.27, respectively. (3) Univariate regression revealed a higher prevalence of MSDs in those older than 45 years (49.5%), length of service > 15 years (56.4%), annual income <$60,000 (79.1%), and moderate burnout (43.2%). (4) Binary logistic regression showed that the prevalence of MSDs was higher for those with 5-20 years of service (OR = 0.295, 95% CI: 0.169-0.513), >20 years of service (OR = 0.845, 95% CI: 0.529-1.350), annual income ≥$60,000 (OR = 1.742, 95% CI: 1.100-2.759), and severe burnout (OR = 0.284, 95% CI: 0.109-0.739), and that these were independent predictors of the occurrence of MSDs among workers in underground coal mine operations (p < 0.05). (5) The areas under the ROC curve for the training and validation sets were 0.665 (95% CI: 0.615-0.716) and 0.630 (95% CI: 0.578-0.682), respectively, indicating that the model has good predictive ability; the calibration plots showed good agreement between the predicted and actual prevalence of the model; and the DCA curves suggested that the predictive value of this nomogram model for MSDs was good. Conclusion: The prevalence of MSDs among workers working underground in coal mines was high, and the constructed nomogram showed good discriminatory ability and optimal accuracy.


Subject(s)
Coal Mining , Musculoskeletal Diseases , Humans , Risk Factors , Musculoskeletal Diseases/epidemiology , Surveys and Questionnaires , Coal
7.
BMC Bioinformatics ; 24(1): 81, 2023 Mar 06.
Article in English | MEDLINE | ID: mdl-36879187

ABSTRACT

OBJECTIVE: To establish a prognostic signature for lung adenocarcinoma (LUAD) based on cuproptosis-related long non-coding RNAs (lncRNAs), and to study the immune-related functions of LUAD. METHODS: First, transcriptome data and clinical data related to LUAD were downloaded from the Cancer Genome Atlas (TCGA), and cuproptosis-related genes were analyzed to identify cuproptosis-related lncRNAs. Univariate COX analysis, least absolute shrinkage and selection operator (LASSO) analysis, and multivariate COX analysis were performed to analyze the cuproptosis-related lncRNAs, and a prognostic signature was established. Second, univariate COX analysis and multivariate COX analysis were performed for independent prognostic analyses. Receiver operating characteristic (ROC) curves, C index, survival curve, nomogram, and principal component analysis (PCA) were performed to evaluate the results of the independent prognostic analyses. Finally, gene enrichment analyses and immune-related function analyses were also carried out. RESULTS: (1) A total of 1,297 cuproptosis-related lncRNAs were screened. (2) A LUAD prognostic signature containing 13 cuproptosis-related lncRNAs was constructed (NIFK-AS1, AC026355.2, SEPSECS-AS1, AL360270.1, AC010999.2, ABCA9-AS1, AC032011.1, AL162632.3, LINC02518, LINC0059, AL031600.2, AP000346.1, AC012409.4). (3) The area under the multi-indicator ROC curves at 1, 3, and 5 years were AUC1 = 0.742, AUC2 = 0.708, and AUC3 = 0.762, respectively. The risk score of the prognostic signature could be used as an independent prognostic factor that was independent of other clinical indicators. (4) The results of gene enrichment analyses showed that 13 biomarkers were primarily related to amoebiasis, the wnt signaling pathway, hematopoietic cell lineage. The ssGSEA volcano map showed significant differences between high- and low-risk groups in immune-related functions, such as human leukocyte antigen (HLA), Type_II_IFN_Reponse, MHC_class_I, and Parainflammation (P < 0.001). CONCLUSIONS: Thirteen cuproptosis-related lncRNAs may be clinical molecular biomarkers for the prognosis of LUAD.


Subject(s)
Adenocarcinoma , Apoptosis , RNA, Long Noncoding , Humans , Lung , Nomograms , Prognosis , RNA, Long Noncoding/genetics , Copper
8.
Dalton Trans ; 52(8): 2309-2316, 2023 Feb 21.
Article in English | MEDLINE | ID: mdl-36723081

ABSTRACT

Metal-organic framework (MOF) materials with aqueous stability have a good potential application in the field of mimetic enzymes. However, most of them have poor robustness in aqueous solution due to competitive coordination effects between water molecules and central metal ions. Herein, a copper-based MOF (Cu-SM MOF) was prepared using copper ions and 5-(sulfomethyl) isophthalic acid (5-SMIPA) by a hydrothermal process. Considering the similarity of coordination and morphology with HKUST-1, the aqueous stability and laccase-like activity of the Cu-SM MOF were investigated using HKUST-1 as the reference. The Cu-SM MOF shows superior aqueous stability to HKUST-1 after immersion in buffer solutions, especially under alkaline conditions. Moreover, the Cu-SM MOF possesses higher catalytic activity than HKUST-1 at a high salt concentration, high temperature, etc., because the Cu-SM MOF exhibits lower Km and higher Vmax values than those of laccase and reported mimetic enzymes. The mimetic enzyme behavior of the Cu-SM MOF is demonstrated in the oxidation of phenols, as well as in the detection of 2,4-dichlorophenol (2,4-DP) and p-nitrophenol with linear ranges of 1-100 µM and 2-250 µM, and limits of detection of 0.53 µM and 1.62 µM, respectively. Owing to the excellent aqueous stability and laccase-like activity of the Cu-SM MOF, it has great application prospects in many fields, such as the determination of phenols and the treatment of industrial wastewater.

9.
Biomater Adv ; 141: 213092, 2022 Oct.
Article in English | MEDLINE | ID: mdl-36191539

ABSTRACT

Functional surfaces that enable both spatial and temporal control of biomolecules immobilization have attracted enormous attention for various fields including smart biointerface materials, high-throughput bioarrays, and fundamental research in the biosciences. Here, a flexible and promising method was presented for regulating the spatiotemporal arrangement of multiple biomolecules by constructing the topographically and chemically diverse polymer brushes patterned surfaces. A series of polymer brushes patterned surfaces, including antifouling brushes patterned surface, epoxy-presenting brushes patterned surface without and with antifouling background layer, were fabricated to control the spatial distribution of protein and cell adhesion through specific and nonspecific means. The fluorescence measurements demonstrated the effectiveness of spatially regulating the density of surface-immobilized protein through controlling the areal thickness of the poly (glycidyl methacrylate) (PGMA) brush patterns, leading to various complex patterns featuring well-defined biomolecule concentration gradients. Furthermore, a multiplexed surface bearing epoxy groups and azido groups with various areal densities was fabricated for regulating the spatiotemporal arrangement of different proteins, enabling binary biomolecules patterns with higher degrees of functionality and complexity. The presented strategy for the spatiotemporal control of biomolecules immobilization would boost the development of dynamic and multifunctional biosystems.


Subject(s)
Immobilized Proteins , Polymers , Cell Adhesion , Polymers/chemistry
10.
RSC Adv ; 12(3): 1375-1383, 2022 Jan 05.
Article in English | MEDLINE | ID: mdl-35425177

ABSTRACT

To improve the performance of lithium-sulfur (Li-S) batteries, herein, based on the idea of designing a material that can adsorb polysulfides and improve the reaction kinetics, a Co,N-co-doped graphene composite (Co-N-G) was prepared. According to the characterization of Co-N-G, there was a homogeneous and dispersed distribution of N and Co active sites embedded in the Co-N-G sample. The 2D sheet-like microstructure and Co, N with a strong binding energy provided significant physical and chemical adsorption functions, which are conducive to the bonding S and suppression of LiPSs. Moreover, the dispersed Co and N as catalysts promoted the reaction kinetics in Li-S batteries via the reutilization of LiPSs and reduced the electrochemical resistance. Thus, the discharge specific capacity in the first cycle for the Co-N-G/S battery reached 1255.7 mA h g-1 at 0.2C. After 100 cycles, it could still reach 803.0 mA h g-1, with a retention rate of about 64%. This phenomenon proves that this type of Co-N-G composite with Co and N catalysts plays an effective role in improving the performance of batteries and can be further studied in Li-S batteries.

11.
Drug Deliv ; 29(1): 1132-1141, 2022 Dec.
Article in English | MEDLINE | ID: mdl-35380084

ABSTRACT

Sodium aescinate (SA) is often used for intravenous (IV) injection owing to its anti-inflammatory, anti-exudative, increasing venous tension, improving blood circulation and reducing swelling activities. However, the clinical application of SA is limited by strong irritation, short half-life and low bioavailability. To overcome these defects, we intended to modify SA by encapsualing it with liposomes . SA was mixed with a proper amount of phospholipid and lyophilized to prepare the liposome of sodium aescinate for injection (SA-Lip-I). Its physical properties, cumulative release and dilution stability were evaluated in vitro. Its pharmacodynamic characteristics were evaluated. Safety of SA-Lip-I was evaluated in terms of hemolysis, IV irritation and acute toxicity. The mean particle size of SA-Lip-I was 117.33±0.95 nm, polydispersity index (PDI) was 0.140±0.017, Zeta potential was -30.34±0.23 mv, The cumulative release of SA-Lip at 12 h was more than 80%, which met the release requirements of nanoparticles. SA-Lip-I was well stable in the four mediators and met the clinical medication requirements. In addition, SA-Lip-I had better efficacy than the SA-I and has a significant difference. Furthermore, SA-Lip-I did not induce hemolysis at 37°C, and produced by far milder venous irritation as compared with SA-I. In addition, LD50 of SA-Lip-I was 2.12 fold that of the commercial SA-I, with no obvious side effects.The modified SA-Lip-I is a promising preparation which can reduce the irritation and toxic side effects, improve the treatment effect to a certain extent, but greatly alleviate pain of the patient during treatment, achieving the optimal curative effect.


Subject(s)
Saponins , Triterpenes , Humans , Liposomes , Water
12.
Talanta ; 238(Pt 2): 123030, 2022 Feb 01.
Article in English | MEDLINE | ID: mdl-34801893

ABSTRACT

The development of analytical method for selective and sensitive detection of gossypol (Gsp), an extraction from the cotton plants, is important but still challenging in food safety and medical field. Herein, we reported a turn-on near infrared (NIR) fluorescence detection strategy for Gsp based on a metal-organic framework (MOF), QBA-Yb, which was prepared from 4,4'-(quinolone-5, 8-diyl) benzoate with Yb(NO3)3·5H2O by solvothermal synthesis. The Gsp acted as another "antenna" to sensitize the luminescence of Yb3+, leading to the turn-on NIR emission upon 467 nm excitation. As Gsp concentration increased, the NIR emission at 973 nm enhanced gradually, thus enabling highly sensitive Gsp detection in a turn-on way. The experiment and theoretical calculation results revealed the presence of strong hydrogen bonds between Gsp molecules and the MOF skeleton. The developed QBA-Yb probe showed excellent characteristics for detection of Gsp molecules, accompanied by wide linear range (5-160 µg/mL), low detection limit (0.65 µg/mL) and short response time (within 10 min). We have further demonstrated that the QBA-Yb probe was successfully applied for the determination of Gsp in real samples of cottonseeds.


Subject(s)
Gossypol , Metal-Organic Frameworks , Fluorescence , Luminescence
13.
Article in English | MEDLINE | ID: mdl-36613066

ABSTRACT

In the process of promoting the strategy of a healthy China, the built environment, as a carrier of human activities, can effectively influence the health level of residents in the light of its functional types. Based on the POI data of four main urban areas in Lanzhou, this paper classifies the built environment in terms of function into four types. The association between different types of built environments and the prevalence of hypertension was investigated by using the community as the study scale, and activity frequency, air pollution and green space were used as mediating variables to investigate whether they could mediate the relationship between built environments and hypertension. The results indicate that communities with a high concentration of commercial service facilities, road and traffic facilities and industrial facilities have a relatively high prevalence of hypertension. By determining the direct, indirect and overall effects of different functional types of built environment on the prevalence of hypertension, it was learned that the construction of public management and service facilities can effectively mitigate the negative effects of hypertension in the surrounding residents. The results of the study contribute to the rational planning of the structure of the built environment, which is beneficial for optimizing the urban structure and preventing and controlling chronic diseases such as hypertension.


Subject(s)
Air Pollution , Hypertension , Humans , Prevalence , Cities/epidemiology , Hypertension/epidemiology , Built Environment , China/epidemiology , Environment Design
15.
Polymers (Basel) ; 12(6)2020 May 30.
Article in English | MEDLINE | ID: mdl-32486274

ABSTRACT

The deformation-induced crystallization of an isotactic polypropylene (iPP) sheet containing a ß-nucleating agent was evaluated. The phase transformation of the ß-modifications was investigated and the crystal morphology was observed at room temperature after stretching at different temperatures. The results showed that the crystallinity increased after solid-state stretching. When the stretching temperature was below the initial crystallization temperature, stretching deformation promoted the orientation of amorphous molecular chains. When the deformation temperature exceeded the crystallization temperature, part of the ß-modifications underwent a phase transformation process and was stretched into a shish-kebab structure. However, once the stretching temperature was close to the melting point, the ß-modifications melted and recrystallized, and the shish-kebab structure underwent stress relaxation due to poor thermal stability, transforming into α-modifications. It was revealed that the crystal phase transformation mechanism of the ß-modifications was based on the orientation of the molecular chains between the adjacent lamellae. In addition, the shish-kebab cylindrite structure played an important role in modifying the tensile and impact properties of the iPP sheet. The tensile and impact strengths increased by as much as 34% and 126%, respectively.

16.
Polymers (Basel) ; 12(4)2020 Apr 10.
Article in English | MEDLINE | ID: mdl-32290221

ABSTRACT

During the "slit die extrusion-hot stretching" process, highly oriented polyamide 6 (PA6) dispersed phase was produced and retained in the polypropylene (PP) matrix directly. By adjusting the stretching forces, the PA6 spherical phase evolved into the ellipsoid, rod-like microfibril with a decreasing average diameter; then, the PA6 microfibrils broke. Moreover, the effects of the PA6 phases formed in the process of the microfibrillation on PP's crystallization behaviors were studied systematically. As the stretching forces increased, the crystallization ability and orientation degree of PP crystals improved significantly. Differential scanning calorimetry and polarizing optical microscopy confirmed the formation of PP spherulite, fan-shaped lamellae and a transcrystalline layer under the induction of the PA6 phases with different morphology. In the PP/PA6 microfibrilar composites (MFCs), PP crystals showed smaller average size, more crystals and stronger interface adhesion due to more excellent heterogeneous nucleation ability of the PA6 microfibrils, which made contributions to the improvement of the melt elasticity responses and oxygen barrier properties of the PP/PA6 polymer blends.

17.
Lab Chip ; 19(16): 2651-2662, 2019 08 21.
Article in English | MEDLINE | ID: mdl-31250865

ABSTRACT

Spatially arranged polymer brushes provide the essential capability of precisely regulating the surface physicochemical and functional properties of various substrates. A novel and flexible polymer brush patterning methodology, which is based on employing a digital mirror device (DMD)-based light modulation technique to spatiotemporally regulate a surface-initiated photoinduced atom transfer radical polymerization (photo-ATRP) process, is presented. Various characterization techniques confirm that the spatially and/or temporally controlled brush formation results in complex PEG-derived brush patterns in accordance with a customized digital image design. A series of step-and-exposure strategies, including in situ multiple exposure, dynamic multiple exposure and dynamic sequential exposure, are developed to implement spatiotemporal regulation of the photo-ATRP process, leading to complex patterned and gradient brushes featuring binary functionalities, pyramid nanostructures and radial directional chemical gradients. Moreover, tunable and radial directional concentration gradients of various biomacromolecules (e.g., streptavidin) are obtained through preparation of height gradients of azido-functionalized brushes and subsequent orthogonal chemical activation aimed at specific protein immobilization. Finally, a unidirectional concentration gradient of fibronectin, surrounded by non-fouling PEG brushes, is fabricated and applied for human umbilical vein endothelial cell (HUVEC) adhesion experiments, whose preliminary results indicate gradient-dependent cell adhesion behavior in response to the concentration gradient of fibronectin. The presented fabrication technique could be integrated with microfluidic devices for sensors and bio-reactors, paving the way for novel approaches for lab-on-a-chip technologies.

18.
Polymers (Basel) ; 11(4)2019 Apr 03.
Article in English | MEDLINE | ID: mdl-30960603

ABSTRACT

The microstructure evolution of an isotactic polypropylene (iPP) sheet during solid-state stretching was studied. The transition of the spherulites-cylindrites was evaluated using in-situ two-dimensional wide-angle and small-angle X-ray scattering methods. The crystallinity of stretched iPP sheets was characterized by differential scanning calorimetry. The crystal morphology was observed by means of scanning electron microscopy. It was found that the differences of crystal microstructure of the iPP sheet depended on the stretching strain, which promoted the orientation of molecular chains. Amorphous molecular chains in the spherulites oriented and formed into a mesophase near the yield point, and the partially ordered mesophase was further stretched to form an oriented cylindrite structure after the yield point. The highest relative content of cylindrites appeared at 15% strain. Notably, as the amorphous phase embedded into the lamellae layer, the crystal size decreased with the increase of strain, which indicated that the crystallinity of the stretched iPP sheet was much higher than that of unstretched iPP sheet. The induced cylindrites structure played a more important role in improving the mechanical properties and heat resistance of iPP sheets. Compared with the unstretched iPP sheets, the tensile strength increased by 28%, the notch impact toughness significantly increased by 78%, and the vicat softening point increased from 104 to 112 °C.

19.
Materials (Basel) ; 11(9)2018 Sep 06.
Article in English | MEDLINE | ID: mdl-30200622

ABSTRACT

In this paper, molybdenum (Mo) thin films are deposited on soda-lime glass (SLG) substrates by direct current magnetron sputtering and heated in three different modes at different temperatures, including substrate heating, annealing treatment, and both substrate heating and annealing treatment. The effects of heating temperature and heating mode on the structures, morphology, optical and electrical properties of Mo thin films were systematically investigated by X-ray diffraction (XRD), Scanning electron microscopy (SEM), atomic force microscope (AFM) and UV-visible spectrophotometer (UV-vis spectra). It is shown that as the substrate and annealing temperature increase, the crystallinity of Mo thin films is improved, and the grain sizes become bigger. Especially in the mode of both substrate heating and annealing treatment at higher temperature, the obtained Mo thin films show higher crystallinity and conductivity. Moreover, with the increase of substrate and annealing temperature in different heating modes, both the surface compactness of Mo films and the optical reflectance increase correspondingly. Furthermore, the Mo film, prepared at the substrate heating temperature of 400 °C and annealed at 400 °C, showed excellent comprehensive performance, and the resistivity is as low as 1.36 × 10-5 Ω·cm. Using this optimized Mo thin film as an electrode, copper indium gallium selenium (CIGS) solar cells have a maximum photo-conversion efficiency of 12.8%.

20.
Ying Yong Sheng Tai Xue Bao ; 24(6): 1661-8, 2013 Jun.
Article in Chinese | MEDLINE | ID: mdl-24066555

ABSTRACT

Based on the 1975-2010 multi-temporal remotely sensed TM and ETM images and meteorological data, in combining with wavelet analysis, trend surface simulation, and interpolation method, this paper analyzed the meteorological elements' spatial distribution and change characteristics in the middle reaches of Heihe River, and elucidated the process of wetland landscape fragmentation in the study area by using the landscape indices patch density (PD), mean patch size (MPS), and patch shape fragment index (FS). The relationships between the wetland landscape fragmentation and climate change were also approached through correlation analysis and multiple stepwise regression analysis. In 1975-2010, the overall distribution patterns of precipitation and temperature in the study area were low precipitation in high temperature regions and high precipitation in low temperature regions, and the main characteristics of climate change were the conversion from dry to wet and from cold to warm. In the whole study period, the wetland landscape fragmentation was mainly manifested in the decrease of MPS, with a decrement of 48.95 hm2, and the increase of PD, with an increment of 0.006 ind x hm(-2).


Subject(s)
Climate Change , Wetlands , China , Computer Simulation , Geographic Information Systems , Models, Theoretical , Remote Sensing Technology , Rivers
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