Endothelium-dependent relaxation induced by sodium fluoride in the rabbit ear artery

Summary Sodium fluoride (NaF) produced concentration-dependent relaxation of isolated rabbit ear artery precontracted with norepinephrine. In contrast, an arterial preparation with the endothelium rubbed off did not relax, but contracted in response to NaF. NaF-induced relaxation was not influenced by indomethacin but was inhibited by methylene blue or N^G-monomethyl-L-arginine. The results indicate that NaF relaxes the artery by releasing a so-called EDRF.     

氟锆酸盐玻璃在中性和碱性水溶液中的耐蚀机理

研究了氟锆酸盐玻璃在中性和碱性水溶液中的耐蚀机理,并讨论了十一种氟化物组分对玻璃耐侵蚀能力的影响。结果表明,易溶的ZrF_4在pH>7时迅速水解生成难溶的Zr(OH)_4,溶解度较小的BaF_2在pH>12时水解生成易溶的Ba(OH)_2。故氟(?)酸盐玻璃在中性和弱碱性介质中耐蚀能力最佳,强碱中次之,酸性中最差。在中性和碱性溶液中,玻璃的侵蚀为扩散控制过程,扩散层由Zr(OH)_4和其它难溶的氢氧化物构成。这一表面扩散层相当致密,保护了内层玻璃不致迅速受到侵蚀。为提高玻璃耐中性和碱性水溶液的侵蚀能力,在设计玻璃组成时,应优先选择水解速度快,其自身及水解产物溶解度小,在表面扩散层内扩散速度慢的氟化物。     

磷酸钙盐对地热水除氟

通过静态吸附试验与现场离子交换柱动态试验，筛选出适用于地热水直接利用的无污染除氟材料－磷酸钙盐，并分别了该除氟剂在固定床、流化床系统中的吸氟容量，通水倍数以及粒径级配、滤层厚度、滤速等设计与运动参数，为生产运行提供了依据。     

对氟镓铟基玻璃析晶稳定性和结构的影响

以20GaF3-15InF3-20CdF2-15ZnF2-10SnF2-20PbF2(GICZSP)为基玻璃,用P2O5替代等摩尔含量CdF2,以改善玻璃的抗析晶能力.利用差示扫描量热分析、拉曼光谱和X射线衍射分析手段,表征不同含量P2O5对玻璃抗析晶性能及结构的影响.结果表明,P2O5的引入提高了玻璃的析晶稳定性.P2O5在玻璃中以不含P O双键的[PO44-,Q0]四面体存在.随着P2O5量的增加,新出现了M[O,F]6八面体结构.     

SrF2颗粒涂覆增强Si/C负极电化学性能

The silicon-based material exhibits a high theoretical specific capacity and is one of the best anode for the next generation of advanced lithium-ion batteries (LIBs). However, it is difficult for the silicon-based anode to form a stable solid-state interphase (SEI) during Li alloy/de-alloy process due to the large volume change (up to 300%) between silicon and Li_4.4Si, which seriously limits the cycle life of the LIBs. Herein, we use strontium fluoride (SrF₂) particle to coat the silicon?carbon (Si/C) electrode (SrF₂@Si/C) to help forming a stable and high mechanical strength SEI by spontaneously embedding the SrF₂ particle into SEI. Meanwhile the formed SEI can inhibit the volume expansion of the silicon?carbon anode during the cycle. The electrochemical test results show that the cycle performance and the ionic conductivity of the SrF₂@Si/C anode has been significantly improved. The X-ray photoelectron spectroscopy (XPS) analysis reveals that there are fewer electrolyte decomposition products formed on the surface of the SrF₂@Si/C anode. This study provides a facile approach to overcome the problems of Si/C electrode during the electrochemical cycling, which will be beneficial to the industrial application of silicon-based anode materials.     

改性活性氧化铝吸附除氟的连续试验研究

针对不同进水水质、运行条件、设备3个方面，对改性活性氧化铝吸附除氟连续试验进行研究。试验结果表明，进水氟质量浓度、进水pH对吸附柱穿透影响显著，进水氟质量浓度从5mg/L下降到2mg/L时，穿透体积提高1.9倍；进水pH从7.6降低到6.0时，穿透体积提高2.6倍以上，当进水pH在6.0~6.5时，穿透体积达到最大值1388倍体积。穿透体积随进水速率提高而下降，在空速1.3~2.0h^-1时，穿透体积下降较小；当空速大于2.0h^-1时，穿透体积随空速增加而快速下降。吸附柱直径及填充高度对穿透体积无影响。     

季铵盐改性MWNTs制备具有抗菌性和自清洁性的PVDF超滤膜

叔铵盐2-二甲氨基氯乙烷盐酸盐(DCH)作为季铵盐的前驱体,通过环氧氯丙烷接枝到氧化多壁碳纳米管(O-MWNTs)上,得到的季铵盐改性多壁碳纳米管(MWNTs)(即N~+-MWNTs)作为添加剂加入铸膜液制备聚偏氟乙烯(PVDF)平板超滤膜(PVDF/N~+-MWNTs膜).场发射扫描电子显微镜(FESEM)用来观测不同的N~+-MWNTs添加量对膜形貌的影响.结果表明,制得的PVDF/N~+-MWNTs复合膜表面粗糙度明显减小,同时亲水性得到明显改善.在对牛血清白蛋白(BSA)的污染-清洗循环实验中,PVDF/N~+-MWNTs复合膜相比于纯PVDF膜,纯水通量由110.5×10~(-5)L·m~(-2)·h~(-1)·Pa~(-1)上升至197.4×10~(-5)L·m~(-2)·h~(-1)·Pa~(-1).此外,通量恢复率(FRR)明显提高,尤其在3次循环之后,对BSA的截留性能没有下降.在对大肠杆菌和金黄色葡萄球菌的抗菌实验中,PVDF/N~+-MWNTs复合膜展现出优异的抑菌性,且在膜的抗菌性再生循环中,3次循环之后PVDF/N+-MWNTs复合膜的抑菌率依然维持在较高的水平.     

基于萘-咟啶鎓受体分子的合成及其对F-的特性识别

设计合成了基于萘-咟啶鎓的受体分子1,通过紫外-可见光谱、荧光光谱研究了受体分子1对9种常见的阴离子(F^-、 Cl^-、 Br^-、 I^-、 CH₃COO^-、 HSO^-₄、 H₂PO^-₄、 ClO^-₄、 NO^-₃)的识别性能.结果发现,受体分子1可选择性的识别F^-.在紫外-可见光谱中,当加入F^-时,受体分子1的溶液由黄色变为无色,可实现裸眼识别,Job^-曲线表明受体分子1和F^-形成了1∶1型氢键络合物,结合常数为(3.05±0.15)×10³ L/mol. 在荧光光谱中,加入F^-后,受体分子1在403 nm处产生强的荧光发射峰,由无荧光变为深蓝色荧光,即具有荧光开启(turn-on)功效,受体分子1检测F^-的线性为1.0×10^-6~3.0×10^-5 mol/L,最低检测限为8.5×10^-6 mol/L. 核磁滴定实验表明受体分子1通过咟啶环上的C(2)-H与F^-之间形成了较强的氢键作用力,而过量F^-的加入会引起受体分子的去质子化.     

Preparation of alumina supported on carbon nanotubes and its application in fluoride adsorption from an aqueous solution

A novel material, alumina supported on carbon nanotubes (Al₂O₃/CNT), was prepared from carbon nanotubes and Al(NO₃)₃.X-ray diffraction (XRD) spectra demonstrate that alumina is amorphous, and scanning electron microscope (SEM) images show that CNT and alumina are homogeneously mixed. Furthermore, the fluoride adsorption behavior on the surface of Al₂O₃ /CNT has been investigated and compared with other adsorbents. The results indicate that Al₂O₃/CNT has a high adsorption capacity, with a saturation adsorption capacity of 39.4 mg/g. It is also found that the adsorption capacity of Al₂O₃/CNT is 3.0—4.5 times that of g-Al₂O₃ while almost equal to that of IRA-410 polymeric resin at 25℃. The adsorption isotherms of fluoride on Al₂O₃/CNT fit the Freundlich equation well, and optimal pH ranging from 5.0 to 9.0.     

聚偏氟乙烯支撑液膜萃取乳酸

采用聚偏氟乙烯固体微孔膜,与溶解在煤油中的三烷基氧磷组成支撑液膜(SLM),分离稀水溶液中的乳酸。考察了pH值、料液浓度、载体浓度、温度、料液及解析液流量对传质速率的影响。同时进行了膜稳定性的定性研究。发现乳酸以分子形式通过SLM;载体浓度为40%时传质速率最大;SLM对乳酸的通量与稀水溶液中乳酸浓度成正比。料液和解析液预先用有机相饱和时,膜的稳定性可大大改善。