International Journal of Polymer Analysis and Characterization最新文献

Synthesis, rheological and thermal studies of Gum ghatti-cl-poly(acrylic acid) hydrogels containing CoFe2O4 nanoparticles 含 CoFe2O4 纳米颗粒的 Gum ghatti-cl-poly(acrylic acid) 水凝胶的合成、流变学和热学研究

IF 1.7 4区工程技术

International Journal of Polymer Analysis and Characterization Pub Date : 2024-10-24 DOI: 10.1080/1023666X.2024.2410746

{"title":"Synthesis, rheological and thermal studies of Gum ghatti-cl-poly(acrylic acid) hydrogels containing CoFe2O4 nanoparticles","authors":"","doi":"10.1080/1023666X.2024.2410746","DOIUrl":"10.1080/1023666X.2024.2410746","url":null,"abstract":"<div><div>In this work, Gum ghatti-cl-poly(acrylic acid)/CoFe<sub>2</sub>O<sub>4</sub> (GGAACF) hydrogels were synthesized using a free radical polymerization technique, with CoFe<sub>2</sub>O<sub>4</sub> nanoparticles incorporated via a co-precipitation method using nitrates as precursors. Thermal gravimetric analysis (TGA) revealed that the inclusion of CoFe<sub>2</sub>O<sub>4</sub> nanoparticles enhanced the thermal stability of the hydrogels. Swelling studies indicated that the addition of 30 mg of CoFe<sub>2</sub>O<sub>4</sub> nanoparticles maximized water retention. Rheological assessments demonstrated non-Newtonian behavior, with flow curves fitted best by the Power Law model. The incorporation of CoFe<sub>2</sub>O<sub>4</sub> nanoparticles significantly improved the hydrogel’s elasticity and viscosity, as evidenced by a higher storage modulus (G′) compared to the loss modulus (G″) across all frequencies, indicating the elastic nature of the hydrogels. The decrease in complex viscosity with increasing frequency confirmed the pseudoplastic properties of the hydrogels, attributed to the random alignment of CoFe<sub>2</sub>O<sub>4</sub> nanoparticles within the matrix. Tan δ values were below unity at all tested frequencies, underscoring the hydrogels’ strong elastic properties. These findings highlight the effectiveness of rheological analysis in characterizing the viscoelastic behavior of polymer hydrogels, which can be tailored for various applications.</div></div>","PeriodicalId":14236,"journal":{"name":"International Journal of Polymer Analysis and Characterization","volume":null,"pages":null},"PeriodicalIF":1.7,"publicationDate":"2024-10-24","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142592607","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 0

Preparation and characterization of fumed silica added PMMA denture base materials 制备添加了气相二氧化硅的 PMMA 义齿基托材料并确定其特性

IF 1.7 4区工程技术

International Journal of Polymer Analysis and Characterization Pub Date : 2024-10-17 DOI: 10.1080/1023666X.2024.2410754

{"title":"Preparation and characterization of fumed silica added PMMA denture base materials","authors":"","doi":"10.1080/1023666X.2024.2410754","DOIUrl":"10.1080/1023666X.2024.2410754","url":null,"abstract":"<div><div>This study was carried out to investigate the chemical, mechanical, and structural properties of increasing amounts of fumed silica added to PMMA denture base material. The effect of adding fumed silica at three different concentrations (0.5%, 1%, and 2% by weight) to PMMA was studied using Fourier transform infrared spectroscopy (FTIR), dynamic mechanical analysis (DMA), density, flexural strength, hardness, atomic force microscopy (AFM), and scanning electron microscopy (SEM). The results showed that the highest flexural strength values (105.64 MPa) and hardness (20.07 microvickers) were obtained with 1% wt. of fumed silica material. According to DMA results, fumed silica samples containing 1% wt. had the highest energy storage (3.24 GPa at 30 °C) and glass transition temperature. As a result, fumed silica in PMMA denture base material reached its maximum saturation limit at 1% wt. A more brittle behavior was observed in samples containing 2% fumed silica, which accumulated on the surface, as confirmed by AFM. The molecular bonds at the resin-fumed silica interface weaken due to the agglomeration of fumed silica. Consequently, the flexural strength and hardness decrease, along with the glass transition temperature and storage modulus. The potential applications of this research are vast, inspiring further exploration and innovation in denture-based materials.</div></div>","PeriodicalId":14236,"journal":{"name":"International Journal of Polymer Analysis and Characterization","volume":null,"pages":null},"PeriodicalIF":1.7,"publicationDate":"2024-10-17","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142592676","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 0

High-performance biodegradable triboelectric nanogenerators using CoFe2O4 filled poly (butylene adipate-co-terephthalate) 使用 CoFe2O4 填充聚（己二酸丁二醇酯-对苯二甲酸乙二醇酯）的高性能可生物降解三电纳米发电机

IF 1.7 4区工程技术

International Journal of Polymer Analysis and Characterization Pub Date : 2024-10-14 DOI: 10.1080/1023666X.2024.2410762

{"title":"High-performance biodegradable triboelectric nanogenerators using CoFe2O4 filled poly (butylene adipate-co-terephthalate)","authors":"","doi":"10.1080/1023666X.2024.2410762","DOIUrl":"10.1080/1023666X.2024.2410762","url":null,"abstract":"<div><div>The hunt for sustainable and efficient energy harvesting and storage devices has driven significant interest in triboelectric nanogenerators (TENGs) as potential alternatives to traditional batteries for powering electronic devices. However, the development of biodegradable TENGs remains a formidable challenge. This study presents the preparation of a tribopositive material entirely composed of biodegradable poly(butylene adipate-co-terephthalate) (PBAT) polymer enhanced with CoFe<sub>2</sub>O<sub>4</sub> (CF) nanoparticles. The CF nanoparticles, synthesized via the combustion method, were incorporated into the PBAT matrix through solvent casting to form films with varied filler content (0.2, 0.4, 0.6, 0.8, and 1 g). The CF nanoparticles structural, surface, and electrical properties were characterized using XRD and FTIR spectroscopy. At the same time, the morphology of the nanomaterials and their composites was analyzed by scanning electron microscopy. Specifically, the 0.8 g PBAT-CF TENG demonstrated superior performance, achieving an output voltage of 45.45 V and a current of 4.5 µA. Subsequent electrical studies, including charging commercial capacitors (1.0 to 47 μF) and powering LEDs and calculators, underscored the device’s efficiency. The PBAT-CF TENG also effectively generated voltage and current signals from physical activities like walking and jumping. This innovative approach highlights the potential for biodegradable, high-performing, self-powered flexible electronics, and wearable devices, paving the way for sustainable technological advancements.</div></div>","PeriodicalId":14236,"journal":{"name":"International Journal of Polymer Analysis and Characterization","volume":null,"pages":null},"PeriodicalIF":1.7,"publicationDate":"2024-10-14","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142592610","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 0

Micromechanical modeling, thermal, and dielectric studies of poly (methyl methacrylate)-barium titanate composites 聚（甲基丙烯酸甲酯）-钛酸钡复合材料的微机械建模、热和介电研究

IF 1.7 4区工程技术

International Journal of Polymer Analysis and Characterization Pub Date : 2024-10-02 DOI: 10.1080/1023666X.2024.2391802

{"title":"Micromechanical modeling, thermal, and dielectric studies of poly (methyl methacrylate)-barium titanate composites","authors":"","doi":"10.1080/1023666X.2024.2391802","DOIUrl":"10.1080/1023666X.2024.2391802","url":null,"abstract":"<div><div>Polymer composites containing poly (methyl methacrylate) (PMMA) and barium titanate (BaTiO<sub>3</sub>) were synthesized using the solution mixing method. The electrical conductivity of PMMA is 6 × 10<sup>−9</sup> S/cm, and adding 2% fillers reduces to 5 × 10<sup>−9</sup> S/cm. The melting point of PMMA is 373 °C, and adding 2% and 4% fillers increased it to 376 °C and 379 °C, respectively. The polymer chains become less mobile and block macromolecules on the filler surface. The modulus of elasticity and mechanical tensile stress of the polymer composites with a 5-wt% of BaTiO<sub>3</sub> are 759.3 MPa and 75.6 MPa, respectively. The breakdown strength of PMMA is 203 KV and reduces with the addition of 5% filler to 144 KV. The values of <em>E c</em>/<em>E m</em> evaluated using the Tsai-Pagano, Christensen-Waals, ROM, Mori-Tanaka, and Halpin-Tsai models underpredict the modulus compared to experimental <em>E c</em>/<em>E m</em> values. Fourier spectroscopy confirmed the presence of Ti-O and BaTiO<sub>3</sub> bonds in the polymer composite. Scanning electron microscope images reveal spherical aggregates of BaTiO<sub>3</sub> coated with PMMA and an interparticle network. The dielectric constant of PMMA is 3 and increased with the addition of 2% and 4% fillers to 4 and 4.3, respectively.</div></div>","PeriodicalId":14236,"journal":{"name":"International Journal of Polymer Analysis and Characterization","volume":null,"pages":null},"PeriodicalIF":1.7,"publicationDate":"2024-10-02","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142359454","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 0

Mechanical, Thermal, and Water Absorption Behavior of Ash Gourd (Benincasa Hispida) Peel Particles Filled Epoxy Composites 灰葫芦（Benincasa Hispida）果皮颗粒填充环氧树脂复合材料的力学、热学和吸水性能

IF 1.7 4区工程技术

International Journal of Polymer Analysis and Characterization Pub Date : 2024-10-02 DOI: 10.1080/1023666X.2024.2378890

{"title":"Mechanical, Thermal, and Water Absorption Behavior of Ash Gourd (Benincasa Hispida) Peel Particles Filled Epoxy Composites","authors":"","doi":"10.1080/1023666X.2024.2378890","DOIUrl":"10.1080/1023666X.2024.2378890","url":null,"abstract":"<div><div>Recently, bio-composites have attracted much attention due to their potential applications in various industries. The most notable benefits are the product’s low cost, biodegradability, lightweight, availability, and ability to solve environmental issues. The present research utilizes ash gourd (<em>Benincasa hispida</em>) peel, a food waste, as a filler material to produce epoxy (EP) composites. The effect of ash gourd peel particle percentage (ranging from 0 to 25 wt.%) was studied on the developed composites’ mechanical and thermal properties and water absorption behavior. The maximum tensile strength, flexural strength, and shore D hardness were 47.52 MPa, 2409.17 MPa, and 79.6respectively, when the ash gourd peel was 5% by weight in the composite. It was observed that the mechanical characteristics of manufactured bio-composites are negatively affected by the high concentration of ash gourd peel particles in the epoxy matrix. Also, increasing ash gourd peel particle fraction increases the water absorption of composites when immersed in distilled, sea, and tap water. The composite with 5% filler by weight absorbs water at a minimal rate when immersed in seawater. Thermogravimetric analysis was conducted to investigate the newly developed composite’s thermal behavior. In addition, a morphological examination of the fractured surfaces was carried out with assistance from a scanning electron microscope. The work presents ash gourd peel particles as the potential alternative to be used as filler in composites.</div></div>","PeriodicalId":14236,"journal":{"name":"International Journal of Polymer Analysis and Characterization","volume":null,"pages":null},"PeriodicalIF":1.7,"publicationDate":"2024-10-02","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"141807387","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 0

Enhanced performance in a NASICON-incorporated solid polymer electrolyte 性能增强的 NASICON 掺杂固体聚合物电解质

IF 1.7 4区工程技术

International Journal of Polymer Analysis and Characterization Pub Date : 2024-10-02 DOI: 10.1080/1023666X.2024.2383460

引用次数: 0

Effect of heat treatment on charge states, thermophysical and mechanical properties of polypropylene doped with ZrO2 nanoparticles 热处理对掺杂 ZrO2 纳米粒子的聚丙烯的电荷状态、热物理性能和机械性能的影响

IF 1.7 4区工程技术

International Journal of Polymer Analysis and Characterization Pub Date : 2024-10-02 DOI: 10.1080/1023666X.2024.2387605

{"title":"Effect of heat treatment on charge states, thermophysical and mechanical properties of polypropylene doped with ZrO2 nanoparticles","authors":"","doi":"10.1080/1023666X.2024.2387605","DOIUrl":"10.1080/1023666X.2024.2387605","url":null,"abstract":"<div><div>Charge states, thermophysical and mechanical properties of polypropylene doped with zirconium oxide nanoparticles, and their changes during heat treatment at temperatures 60 °C, 100 °C, and 140 °C are studied. The methods used are thermal stimulated depolarization (TSD), scanning differential calorimetry (SDC), and mechanical life assessment. It is shown that with an increase in the concentration of the filler, the intensity of the TSD peaks increases up to 3 vol.%. A further increase in concentration leads to a decrease in the intensity of the peaks. The activation energy of charge release from traps, temperature of maximum of the peaks, and the magnitude of the accumulated charge in the traps have also maximal value at nanoparticle concentration of 3 vol.%. The study of charge characteristics of the nanocomposite with concentration of 3 vol.% after heat treatment shows that the intensity of TSD peaks, the temperature of peak maxima, and the activation energy of charge release increase with increasing pretreatment temperature. The magnitude of the charge accumulated in traps has a maximal value at treatment temperature of 140 °C owing to the increase in the number of traps. The melting point of the composite is 149.38 °C and shifts to 146.88 °C after heat treatment at 140 °C. It indicates that the high temperature of heat treatment leads to partial destruction of polymer chains, leading to a decrease in the critical melting temperature. The mechanical durability of PP + 3%ZrO<sub>2</sub> nanocomposite decreases with increase in pretreatment temperature.</div></div>","PeriodicalId":14236,"journal":{"name":"International Journal of Polymer Analysis and Characterization","volume":null,"pages":null},"PeriodicalIF":1.7,"publicationDate":"2024-10-02","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"141943869","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 0

Fabrication, structure and optical characteristics of CuO/polymer nanocomposites materials for optical devices 用于光学设备的氧化铜/聚合物纳米复合材料的制备、结构和光学特性

IF 1.7 4区工程技术

International Journal of Polymer Analysis and Characterization Pub Date : 2024-10-02 DOI: 10.1080/1023666X.2024.2397392

{"title":"Fabrication, structure and optical characteristics of CuO/polymer nanocomposites materials for optical devices","authors":"","doi":"10.1080/1023666X.2024.2397392","DOIUrl":"10.1080/1023666X.2024.2397392","url":null,"abstract":"<div><div>The films of P(4ClAni)/CuO, which formed of mixing poly 4-chloroaniline P(4ClAni) by CuO, were fabricated by the casting solution method. The XRD confirmed the successful prepration of the P(4ClAni)/CuO films. Additionally, the effect of CuO on the optical characteristics was determined. The CuO increased the refractive index from 1.09 for P(4ClAni) to 1.11 for P(4ClAni)/CuO-1, and 1.19 for P(4ClAni)/CuO-3, respectively, while the oscillation energy E<sub>0</sub> dropped from 4.29 eV for P(4ClAni) to 3.57 eV for P(4ClAni)/CuO-1, 3.12 eV for P(4ClAni)/CuO-2, and 3.06 eV for P(4ClAni)/CuO-3. The charge transfer between P(4ClAni) and CuO increased optical conductivity as the CuO ratios increased. This suggests that modifications in the electronic structure of the composite due to the interactions between P(4ClAni) and CuO. Also, the plasma frequency increased from 0.87 x 10<sup>12</sup> s<sup>−1</sup> to 2.32 x 10<sup>12</sup> s<sup>−1</sup>. These changes in optical parameters occurred when the polarization of the P(4ClAni)/CuO was altered. The study elucidated the advantages of incorporating CuO nanoparticles as fillers in improving the properties of P(4ClAni) structures. The obtained results indicate the P(4ClAni)/CuO composites were sucessfuly fabricated with novel characteristics that can be applied in flexible optical devices.</div></div>","PeriodicalId":14236,"journal":{"name":"International Journal of Polymer Analysis and Characterization","volume":null,"pages":null},"PeriodicalIF":1.7,"publicationDate":"2024-10-02","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142359456","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 0

Improving flame resistance and shielding properties for cross-linked polyethylene (XLPE) using nanoclay filler 使用纳米粘土填料提高交联聚乙烯（XLPE）的阻燃性和屏蔽性能

IF 1.7 4区工程技术

International Journal of Polymer Analysis and Characterization Pub Date : 2024-10-02 DOI: 10.1080/1023666X.2024.2394226

{"title":"Improving flame resistance and shielding properties for cross-linked polyethylene (XLPE) using nanoclay filler","authors":"","doi":"10.1080/1023666X.2024.2394226","DOIUrl":"10.1080/1023666X.2024.2394226","url":null,"abstract":"<div><div>Polymers play an essential role in both industry and medical fields due to their diverse and adaptable properties. In this work, prepared crosslinking polyethylene (XLPE) samples with hydrophilic bentonite nanoclay fillers (H<sub>2</sub>Al<sub>2</sub>O<sub>6</sub>Si) at concentrations of 0, 1, 2.5, 4, and 5 wt% enhance their flame-retardant and radiation shielding efficiency. The research investigated flame retardancy and thermal stability parameters. The XLPE/H<sub>2</sub>Al<sub>2</sub>O<sub>6</sub>Si nanocomposite polymer sheets were exposed to a collimated beam of fast neutrons using an Am/Be neutron source (5 Ci) and to gamma radiation using a <sup>137</sup>Cs point source (5 μCi) to assess their radiation shielding properties. The study found that uniform dispersion of nanoclay particles enhanced the thermal properties of the composite, forming a char layer that acted as a barrier, slowing thermal decomposition and reducing the heat release rate. Limiting oxygen index (LOI) increased from 28% to 34%, and burning rate improved with higher nanoclay concentrations. Additionally, absorption and optical band gap calculations decreased with increasing filler concentrations. Radiation attenuation capabilities increased by approximately 40% for neutrons and 30% for gamma radiation compared to pure XLPE. The study concluded that incorporating nanoclay fillers into XLPE enhances its shielding capabilities and improves flame resistance properties, making the prepared samples suitable for various industrial applications.</div></div>","PeriodicalId":14236,"journal":{"name":"International Journal of Polymer Analysis and Characterization","volume":null,"pages":null},"PeriodicalIF":1.7,"publicationDate":"2024-10-02","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142208273","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 0

Response surface methodology-based preparation of sago starch bioplastic film for food packaging 基于响应面方法制备食品包装用西米淀粉生物塑料薄膜

IF 1.7 4区工程技术

International Journal of Polymer Analysis and Characterization Pub Date : 2024-10-02 DOI: 10.1080/1023666X.2024.2383480

{"title":"Response surface methodology-based preparation of sago starch bioplastic film for food packaging","authors":"","doi":"10.1080/1023666X.2024.2383480","DOIUrl":"10.1080/1023666X.2024.2383480","url":null,"abstract":"<div><div>The increase in the use of plastics during the past few decades has caused environmental pollution due to the non-biodegradable and recalcitrance nature of the plastics. This has caused great problems for the solid waste management efforts. The development of biodegradable polymers from natural and renewable ingredients can address the challenges caused by plastic pollution. The present work deals with the optimization of the preparation process of sago starch-based biodegradable bioplastic films. The sago starch, glycerol-sorbitol mixture, and chitosan were used as polysaccharides, plasticizers, and antimicrobial agents, respectively. The factors screening and design optimization were performed using response surface methodology and Box-Behnken Design to investigate the interactions between all components in the film preparation. Furthermore, the developed bioplastic films were characterized through field emission scanning electron microscopy and Fourier transform infrared spectroscopy. The antimicrobial susceptibility assay showed the inhibition of the growth of <em>Bacillus pumilus</em> and <em>Alcaligenes faecalis XF1</em> by incorporation of cinnamon essential oil into the film. Moreover, the developed films successfully reduced the proliferation of fungal growth on packaged bread samples. The microbial analysis found that the shelf life of the wheat bread was improved from 3 to 15 days. The sago starch bioplastic films developed in this study can potentially meet the requirements for food packaging films.</div></div>","PeriodicalId":14236,"journal":{"name":"International Journal of Polymer Analysis and Characterization","volume":null,"pages":null},"PeriodicalIF":1.7,"publicationDate":"2024-10-02","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"141925027","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 0