Binder

粘合剂
  • 文章类型: Journal Article
    聚合物粘合剂的开发对于满足现代储能技术日益增长的需求是必要的。虽然含邻苯二酚的材料在硅阳极中被证明是成功的,它们在有机电池中的应用仍有待探索。在这一贡献中,描述了具有几乎相同的侧链组成但不同主链结构的四种聚合物的合成。该材料用于研究聚合物主链结构对含儿茶酚材料的结合能力的影响。与常用聚偏二氟乙烯(PVDF)粘合剂的比较分析旨在解决两个关键问题:1)富含邻苯二酚的聚合物能否替代PVDF用于有机阴极?和2)聚合物主链的选择是否会影响电池的性能?。研究表明,超分子相互作用,如π-π堆叠和配位键合,是儿茶酚粘合剂的关键特征。在富含邻苯二酚的聚合物中,聚丙烯酸酯粘合剂脱颖而出,很可能归因于它的高度灵活性。此外,在富含邻苯二酚的聚降冰片烯中引入氧原子可增强锂离子导电性和倍率性能。总的来说,研究结果强调了含邻苯二酚的聚合物作为有机阴极粘合剂的可行性,聚合物骨架的选择是其用作锂离子电池粘合剂材料的关键因素。
    The development of polymer binders is necessary to meet the growing demands of modern energy storage technologies. While catechol-containing materials are proven successful in silicon anodes, their application in organic batteries remains unexplored. In this contribution, the synthesis of four polymers are described with nearly identical side chain composition but varying backbone structures. The materials are used to investigate the effect of polymer backbone structure on the binding abilities of catechol-containing materials. Comparative analysis with the commonly used polyvinylidene fluoride (PVDF) binder aims to address two critical questions: 1) Can catechol-rich polymers replace PVDF for use in organic cathodes? and 2) Does the choice of polymer backbone affect the performance of the battery?. The investigation reveals that supramolecular interactions, such as π-π stacking and coordination bonding, are pivotal features of catechol binders. Among the catechol-rich polymers, the polyacrylate binder stands out, likely attributed to its high flexibility. Additionally, introducing an oxygen atom into a catechol-rich polynorbornene enhances lithium-ion conductivity and rate performance. Overall, the findings highlight the viability of catechol-containing polymers as organic cathode binders, and that the choice of polymer backbone is a crucial factor for their use as lithium-ion battery binder materials.
    导出

    更多引用

    收藏

    翻译标题摘要

    我要上传

    求助全文

  • 文章类型: Journal Article
    新型高效催化剂粘合剂材料的设计和开发对于提高高温质子交换膜燃料电池(HT-PEMFC)的电池性能至关重要。在这项研究中,一系列四氟苯基膦酸基粘结剂材料(PF-y-P,使用超强酸催化的Friedel-Crafts反应和组合的Michaelis-Arbuzov反应,制备了具有刚性结构和可控磷酸化度的y=1、0.83和0.67)并用于HT-PEMFCs。样品表现出高稳定性,低吸水率,优越的质子传导率,和电池性能。此外,使用高温微电极电化学测试技术研究了PF-1-P粘合剂的氧传质性能。与磷酸掺杂的聚苯并咪唑(PBI)粘结剂相比,PF-1-P粘合剂材料的O2溶解度增加了30%(5.36×10-6molcm-3),并且PF-1-P粘合剂材料在HT-PEMFC中表现出更好的电池稳定性。在0.12Acm-2的恒定电流下放电10.5h后,在PF-1-P和PBI粘合剂的情况下,MEA电压降低了7.1%和20.8%,分别。
    The design and development of new and efficient catalyst binder materials are important for improving cell performance in high-temperature proton-exchange membrane fuel cells (HT-PEMFCs). In this study, a series of tetrafluorophenyl phosphonic acid-based binder materials (PF-y-P, y = 1, 0.83, and 0.67) with rigid structures and controllable degrees of phosphonation were prepared and used in HT-PEMFCs using the ultra-strong acid-catalyzed Friedel-Crafts reaction and the combined Michaelis-Arbuzov reaction. The samples exhibited high stability, low water uptake, superior proton conductivity, and cell performance. In addition, the oxygen mass transport properties of the PF-1-P binder were investigated using high-temperature microelectrode electrochemical testing techniques. Compared with the phosphoric acid-doped polybenzimidazole (PBI) binder, the O2 solubility of PF-1-P binder material increased by 30% (5.36 × 10-6 mol cm-3) and the PF-1-P binder material exhibited better cell stability in HT-PEMFCs. After 10.5 h of discharge at a constant current of 0.12 A cm-2, the MEA voltage decreased by 7.1% and 20.8% in case of the PF-1-P and PBI binders, respectively.
    导出

    更多引用

    收藏

    翻译标题摘要

    我要上传

    求助全文

  • 文章类型: Journal Article
    城市固体废物焚烧飞灰(MSWIFA)的大量生产强调了开发高效固化材料的重要性。本研究采用MgO和CaO固定MSWIFA(掺入70%粉煤灰),并与硅酸盐水泥(PC)的固定化效果进行了比较。实验结果表明,MgO对重金属(Cd,Cu,Pb,和Zn)与CaO和PC相比。XRD,FTIR,TG,和SEM分析表明,MgO固化的MSWIFA粘结剂中的主要水化产物,CaO,和PC是Mg(OH)2,CaCO3和C-S-H凝胶,分别。Mg(OH)2通过化学络合和表面吸附机制有效地固定了重金属。MgO处理的MSWIFA显示出最高的残留分数和最低的易浸出分数。此外,重金属的浸出特性受pH水平的显著影响,因此,MgO处理的MSWIFA的渗滤液pH为9.18,可实现大多数重金属的沉淀和稳定。总之,本研究为MSWIFA固定化提供了有效的材料选择,并为MSWIFA管理提供了新的策略。
    The significant production of municipal solid waste incineration fly ash (MSWI FA) underscores the importance of developing efficient solidification materials. This study employed MgO and CaO for immobilizing MSWI FA (with a 70% fly ash incorporation), and the immobilization effect was compared with that of Portland cement (PC). Experimental findings revealed that MgO exhibited the most effective stabilization for heavy metals (Cd, Cu, Pb, and Zn) compared to CaO and PC. XRD, FTIR, TG, and SEM analysis indicated that the principal hydration products in MSWI FA binders solidified with MgO, CaO, and PC were Mg(OH)2, CaCO3, and C-S-H gel, respectively. Mg(OH)2 efficiently immobilized heavy metals through chemical complexation and surface adsorption mechanisms. The MgO-treated MSWI FA demonstrated the highest residual fractions and the lowest easily leachable fractions. Moreover, the leaching characteristics of heavy metals were significantly influenced by the pH level, so MgO-treated MSWI FA with a leachate pH of 9.18 achieved the precipitation and stabilization of most heavy metals. In summary, this study provided an effective material selection for MSWI FA immobilization and presented a novel strategy for MSWI FA management.
    导出

    更多引用

    收藏

    翻译标题摘要

    我要上传

    求助全文

  • 文章类型: Journal Article
    自从秦兵马俑出土以来,聚酰胺650交联的E-44环氧树脂粘合剂已用于粘合和恢复它们。在本文中,通过红外光谱研究了兵马俑在过去30年中在室内自然环境中使用的粘合剂的化学老化,X射线光电子能谱和热重分析。结果表明,在所有确定的粘合剂的红外光谱中,粘合剂在1700cm-1处均未出现羰基拉伸振动的特征峰,它们的热分解曲线没有出现任何异常变化,热分解主要发生在300℃以上。有明显的陶瓷颗粒附着在粘合剂的表面上,被剥离用于取样。这些结果表明,秦兵马俑中的粘合剂没有表现出可观察到的化学老化,并且仍然具有很强的粘附力。一般来说,由于自然老化和加速人工老化无法重现复杂天气条件的影响,因此在自然老化和加速人工老化之间存在差异。与人工加速衰老相比,评估结果是用于修复真人大小的秦兵马俑的粘合剂长期自然老化,在目前的调查中,在预测恢复的兵马俑的安全性方面更可靠。
    Since the Qin terracotta warriors were unearthed, polyamide 650 cross-linked E-44 epoxy resin binder has been employed to bond and restore them. In this paper, the chemical aging of the binders service in indoor natural environment during the past 30 years in the terracotta warriors was studied by means of infrared spectroscopy, X-ray photoelectron spectroscopy and thermogravimetric analysis. The results indicated that the binders did not emerge the characteristic peak of carbonyl stretching vibration at 1700 cm-1 in the IR spectra of all determined binders, and their thermal decomposition curves did not emerge any abnormal changes, and the thermal decomposition mainly occurred above 300 °C. There are evident ceramic grains attached to the surface of the binders being peeled off for sampling. These results that the binders service in the Qin terracotta warriors did not exhibit an observable chemical aging and still has strong adhesion. Generally, discrepancies were observed between natural aging and accelerated artificial aging due to the ineffectiveness of the latter to reproduce the effects of complex weather conditions. Compared to artificially accelerated aging, the evaluation results in a long-term natural aging of the binder which is used for restoration of the life-size Qin terracotta warriors, providing in the present investigation, are more reliable in terms of predicting the safety of restored terracotta warriors.
    导出

    更多引用

    收藏

    翻译标题摘要

    我要上传

       PDF(Pubmed)

  • 文章类型: Journal Article
    聚偏氟乙烯(PVDF)具有独特的电化学抗氧化性,是长期以来电池行业唯一的高压正极材料粘合剂。然而,PVDF仍然有一些缺点,如氟的环境限制,对环境湿度的严格要求,附着力弱,锂离子导电性差。在这里,通过掺入酚酞聚醚酮(PEK-C)和酚酞聚醚砜(PES-C)作为粘合剂材料,成功地解决了与高电压锂钴氧化物(LiCoO2;LCO)相关的长期问题。这些粘合剂具有意想不到的耐电化学氧化性和坚固的附着力,确保LCO表面的均匀覆盖,并建立有效且快速的离子导电CEI/粘合剂复合层。通过利用这些有利的特性,基于聚芳醚粘合剂的电极显示出比使用传统PVDF粘合剂的相应电极显著更好的循环和倍率性能。快速离子导电CEI/粘合剂复合层有效地减轻阴极-电解质界面处的不利反应。如预期,使用酚酞聚芳醚粘合剂的电池在4.5和4.6V下进行200和500次循环后,容量保持率分别为88.92%和80.4%,分别。粘合剂的应用,如聚芳基醚粘合剂,为设计高能量密度电池材料提供了一种简单而鼓舞人心的方法。
    Polyvinylidene fluoride (PVDF) has unique electrochemical oxidation resistance and is the only binder for high-voltage cathode materials in the battery industry for a long time. However, PVDF still has some drawbacks, such as environmental limitations on fluorine, strict requirements for environmental humidity, weak adhesion, and poor lithium ion conductivity. Herein, the long-standing issues associated with high-voltage lithium cobalt oxide (LiCoO2; LCO) are successfully addressed by incorporating phenolphthalein polyetherketone (PEK-C) and phenolphthalein polyethersulfone (PES-C) as binder materials. These binders have unexpected electrochemical oxidation resistance and robustness adhesion, ensure uniform coverage on the surface of LCO, and establish an effective and fast ion-conductive CEI/binder composite layer. By leveraging these favorable characteristics, electrodes based on polyarylether binders demonstrate significantly better cycling and rate performance than their counterparts using traditional PVDF binders. The fast ion-conductive CEI/binder composite layer effectively mitigates adverse reactions at the cathode-electrolyte interface. As anticipated, batteries utilizing phenolphthalein polyarylether binders exhibit capacity retention rates of 88.92% and 80.4% after 200 and 500 cycles at 4.5 and 4.6 V, respectively. The application of binders, such as polyarylether binders, offers a straightforward and inspiring approach for designing high-energy-density battery materials.
    导出

    更多引用

    收藏

    翻译标题摘要

    我要上传

    求助全文

  • 文章类型: Journal Article
    根据欧盟委员会的要求,EFSA被要求就海泡石作为所有动物物种的技术饲料添加剂的安全性发表科学意见。2022年,动物饲料中使用的添加剂和产品或物质小组(FEEDAP)就同一添加剂的安全性和有效性发表了意见。专家小组的结论是,海泡石用作饲料添加剂对消费者和环境都是安全的,并有效作为增稠剂悬浮剂,在建议的使用条件下,所有动物物种的饲料中的粘合剂和防结块剂。该添加剂不被认为是眼睛或皮肤刺激物。然而,它被认为是一种呼吸刺激物,呼吸和皮肤致敏剂;由于粉尘潜力及其二氧化硅含量,该添加剂被认为是吸入的风险.关于目标物种,在先前的意见中,专家小组就乳品反刍动物添加剂的安全性得出结论。然而,无法得出所有其他物种/类别的结论。根据鸡对育肥的耐受性研究,在当前评估中评估的断奶仔猪和鳟鱼,之前评估过的奶牛,专家小组的结论是,以20,000mg/kg的最高推荐量加入海泡石对所有动物物种都是安全的。
    Following a request from the European Commission, EFSA was asked to deliver a scientific opinion on the safety of sepiolite as a technological feed additive for all animal species. In 2022, the Panel on Additives and Products or Substances used in Animal Feed (FEEDAP) delivered an Opinion on the safety and efficacy of the same additive. The Panel concluded that sepiolite used as a feed additive is safe for the consumers and the environment, and efficacious as a thickener-suspending agent, binder and anticaking agent in feed for all animal species under the proposed conditions of use. The additive was not considered an eye or skin irritant. However, it was considered a respiratory irritant, a respiratory and dermal sensitiser; owing to the dusting potential and its silica content, the additive was considered a risk by inhalation. Regarding the target species, in the previous Opinion, the Panel concluded on the safety of the additive for dairy ruminants. However, no conclusion could be drawn for all other species/categories. Based on the tolerance studies in chickens for fattening, weaned piglets and trout evaluated in the current assessment, and the one in dairy cows previously assessed, the Panel concluded that the inclusion of sepiolite at the maximum recommended level of 20,000 mg/kg complete feed is safe for all animal species.
    导出

    更多引用

    收藏

    翻译标题摘要

    我要上传

       PDF(Pubmed)

  • 文章类型: Journal Article
    粘合剂对于保持电极的机械稳定性至关重要。然而,传统的粘合剂不能充分缓冲Zn2SiO4阳极的体积膨胀,导致电极接触故障和循环过程中相当大的容量损失。在这项研究中,我们提出了一个简单而有效的解决方案,以解决这些挑战,通过一个组合战略的中空结构设计和引入水性锂聚(丙烯酸)(LiPAA)粘合剂。中空结构可以缩短离子传输距离并适应外部体积变化。LiPAA粘合剂的优异粘附性在活性Zn2SiO4颗粒之间产生了牢固的连接,导电添加剂,和集电器,这增强了电极的机械稳定性和完整性。由于这些积极因素,使用LiPAA作为粘合剂的Zn2SiO4电极可以在5Ag-1的高电流密度下提供499mAhg-1的出色容量,并且在1Ag-1下具有1000个循环的长寿命,容量保持率为98%,显着优于其他粘合剂。正如非原位X射线衍射和非原位X射线吸收光谱所证明的那样,锂离子在Zn2SiO4中的存储遵循双重转化-合金化机制,以Zn为氧化还原中心。在这个过程中,Zn首先被还原成金属Zn,然后在锂离子插入时形成LiZn合金。这项工作表明,LiPAA提供了一种有前途的方法来提高锂离子电池中转换和合金化阳极的循环寿命。
    Binders are crucial for maintaining the mechanical stability of the electrodes. However, traditional binders fail to adequately buffer the volume expansion of Zn2SiO4 anode, causing electrode contact failure and considerable capacity loss during cycling. In this study, we propose a simple and effective solution to address these challenges through a combined strategy of hollow structure design and the introduction of an aqueous lithium poly(acrylic acid) (LiPAA) binder. Hollow structures can shorten ion-transfer distance and accommodate volume change outside. The excellent adhesion of the LiPAA binder created a secure connection between the active Zn2SiO4 particles, conductive additives, and the current collector, which enhanced the mechanical stability and integrity of the electrode. As a result of these positive factors, a Zn2SiO4 electrode using LiPAA as a binder can deliver an excellent capacity of 499 mAh g-1 at a high current density of 5 A g-1 and a long life span of 1000 cycles at 1 A g-1 with a capacity retention of 98%, which significantly outperforms other binders. As demonstrated by ex situ X-ray diffraction and ex situ X-ray absorption spectroscopy, the storage of lithium ions in Zn2SiO4 follows a dual conversion-alloying mechanism, using Zn as the redox center. In this process, Zn is first reduced to metallic Zn and then forms a LiZn alloy upon lithium-ion insertion. This work shows that LiPAA offers a promising approach to improve the cycling longevity of conversion and alloying anodes in Li-ion batteries.
    导出

    更多引用

    收藏

    翻译标题摘要

    我要上传

    求助全文

  • 文章类型: Journal Article
    尽管硅(Si)具有很高的理论容量,锂化过程中的大体积膨胀极大地阻碍了其在高能量密度锂离子电池(LIBs)中的应用。在改善Si阳极性能的策略中,粘合剂的作用不可低估。这里,已经提出了一种设计用于Si阳极的可交联粘合剂的新策略。具有羟基和腈基团的粘合剂可以通过电池中的酰胺基团原位共价交联。交联粘合剂(c-P0AH)显示高弹性和对Si颗粒和集电器的强粘附性。使用c-P0AH粘合剂的Si|Li半硬币电池具有优异的循环性能,并且在0.2C下100次循环后的容量保持率为67.1%。扫描电子显微镜图像显示,c-P0AH粘合剂可以有助于抑制Si阳极的粉碎。此外,X射线光电光谱研究表明,液体电解质在Si阳极上的分解已得到缓解,并且c-POAH粘合剂可以促进更稳定的SEI膜的形成。我们通过原位交联赋予粘合剂良好弹性的策略为开发粘合剂开辟了一条新的路线,这必将促进Si阳极在高能量密度LIB中的应用。
    Although silicon (Si) has a high theoretical capacity, the large volume expansion during lithiation has greatly hindered its application in high-energy-density lithium-ion batteries (LIBs). Among the strategies for improving the performance of Si anode, the role of binders should not be underestimated. Here, a novel strategy for designing a cross-linkable binder for Si anode has been proposed. The binder with hydroxyl and nitrile groups can be in situ covalently cross-linked through the amide group in the batteries. The cross-linked binder (c-POAH) shows high elasticity and strong adhesion to Si particles and the current collector. Si||Li half coin cells using the c-POAH binder have excellent cycle performance and the capacity retention ratio is 67.1% after 100 cycles at 0.2 C. Scanning electronic microscopy images show that the c-POAH binder can contribute to suppressing the pulverization of the Si anode. Moreover, the investigation with X-ray photoelectronic spectrum demonstrates that the decomposition of the liquid electrolyte on Si anode has been mitigated and the c-POAH binder can promote the formation of a more stable SEI film. Our strategy of endowing the binder with good elasticity through in situ cross-linking has opened up a new route for developing binders, which will definitely promote the application of Si anodes in high-energy-density LIBs.
    导出

    更多引用

    收藏

    翻译标题摘要

    我要上传

    求助全文

  • 文章类型: Journal Article
    在这项研究中,直接写入3D打印方法用于使用陶瓷材料制造数字化间固体氧化物燃料电池(SOFC)。使用LSCF(La0.6Sr0.2Fe0.8Co0.22O3-δ)浆料负载和聚乙烯醇缩丁醛(PVB)粘合剂制造阴极电极。评估了具有不同LSCF浆料负载量和PVB粘合剂浓度的浆料的流变参数,以确定它们在微观结构方面对阴极痕量性能的影响。尺寸,和阻力。此外,研究了烧结后LSCF线的尺寸收缩对阴极线宽和高度的影响。此外,压力等直接写入工艺参数的影响,喷嘴和基板之间的距离,和速度上的阴极线尺寸和电阻被评估。含50%固体的LSCF浆液,12%粘合剂,和0.2%的分散剂浓度被确定为使用直接写入方法制造SOFC的最佳值。直接写入过程参数,除了粘合剂和LSCF浆料的浓度比,对阴极线的微观结构有相当大的影响。根据方差分析的结果,压力和距离对阴极电极电阻有显著影响。喷嘴和基板之间的距离增加,速度,或直接写入过程的挤压压力增加了阴极线的电阻。这些发现增加了完善SOFC制造技术的持续努力,为SOFC在能源应用中的先进性能和效率开辟了道路。
    In this research, a direct-write 3D-printing method was utilized for the fabrication of inter-digitized solid oxide fuel cells (SOFCs) using ceramic materials. The cathode electrode was fabricated using the LSCF (La0.6Sr0.2Fe0.8Co0.2O3-δ) slurry loading and the Polyvinyl butyral (PVB) binder. The rheological parameters of slurries with varying LSCF slurry loading and PVB binder concentration were evaluated to determine their effect on the cathode trace performance in terms of microstructure, size, and resistance. Additionally, the dimensional shrinkage of LSCF lines after sintering was investigated to realize their influence on cathode line width and height. Moreover, the effect of the direct-write process parameters such as pressure, distance between the nozzle and substrate, and speed on the cathode line dimensions and resistance was evaluated. LSCF slurry with 50% solid loading, 12% binder, and 0.2% dispersant concentration was determined to be the optimal value for the fabrication of SOFCs using the direct-write method. The direct-write process parameters, in addition to the binder and LSCF slurry concentration ratios, had a considerable impact on the microstructure of cathode lines. Based on ANOVA findings, pressure and distance had significant effects on the cathode electrode resistance. An increase in the distance between the nozzle and substrate, speed, or extrusion pressure of the direct writing process increased the resistance of the cathode lines. These findings add to the ongoing effort to refine SOFC fabrication techniques, opening the avenues for advanced performance and efficiency of SOFCs in energy applications.
    导出

    更多引用

    收藏

    翻译标题摘要

    我要上传

       PDF(Pubmed)

  • 文章类型: Journal Article
    纤维状胶原蛋白的过度沉积是纤维化的标志。胶原纤维的形成需要通过前胶原N-和C-蛋白酶(PNP和PCP)进行蛋白水解成熟,以去除N-和C-前肽,从而将前胶原保持在可溶形式。前胶原C-蛋白酶增强子-1(PCPE-1,一种由两个CUB和一个NTR结构域组成的糖蛋白)是一种调节蛋白,可通过主要PCP激活前胶原的C端加工。它通常在纤维化疾病中上调,代表了开发新的抗纤维化策略的有希望的目标。这里,我们的目标是基于纳米抗体支架开发第一批PCPE-1拮抗剂.使用通过美洲驼免疫的体内选择和使用合成文库的体外选择,我们产生了18个针对PCPE1的CUB结构域的纳米抗体,它们具有增强活性。其中,来自免疫文库的I5和来自合成文库的H4对PCPE-1具有高亲和力,并抑制其与原荧光素的相互作用。PCPE-1,H4和I5形成的复合物的晶体结构表明它们具有不同的表位,并且能够设计双位融合体,双抗体diab-D1。Diab-D1对PCPE-1具有亚纳摩尔亲和力,是其活性的有效拮抗剂,在体外防止刺激前胶原裂解。此外,Diab-D1还可有效减少人真皮成纤维细胞培养物中的前胶原I的蛋白水解成熟,因此有望作为在纤维化条件下调节胶原蛋白沉积的工具。
    The excessive deposition of fibrillar collagens is a hallmark of fibrosis. Collagen fibril formation requires proteolytic maturations by Procollagen N- and C-proteinases (PNPs and PCPs) to remove the N- and C-propeptides which maintain procollagens in the soluble form. Procollagen C-Proteinase Enhancer-1 (PCPE-1, a glycoprotein composed of two CUB domains and one NTR domain) is a regulatory protein that activates the C-terminal processing of procollagens by the main PCPs. It is often up-regulated in fibrotic diseases and represents a promising target for the development of novel anti-fibrotic strategies. Here, our objective was to develop the first antagonists of PCPE-1, based on the nanobody scaffold. Using both an in vivo selection through the immunization of a llama and an in vitro selection with a synthetic library, we generated 18 nanobodies directed against the CUB domains of PCPE1, which carry its enhancing activity. Among them, I5 from the immune library and H4 from the synthetic library have a high affinity for PCPE-1 and inhibit its interaction with procollagens. The crystal structure of the complex formed by PCPE-1, H4 and I5 showed that they have distinct epitopes and enabled the design of a biparatopic fusion, the diabody diab-D1. Diab-D1 has a sub-nanomolar affinity for PCPE-1 and is a potent antagonist of its activity, preventing the stimulation of procollagen cleavage in vitro. Moreover, Diab-D1 is also effective in reducing the proteolytic maturation of procollagen I in cultures of human dermal fibroblasts and hence holds great promise as a tool to modulate collagen deposition in fibrotic conditions.
    导出

    更多引用

    收藏

    翻译标题摘要

    我要上传

    求助全文

公众号