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991.
Calcium hydrogen phosphate dihydrate (CaHPO4·2H2O, CHPD) a dissolved mineral in urine is known to cause renal or bladder stones in both human and animals. Growth of CHPD or brushite using sodium metasilicate gel techniques followed by light and polarizing microscopic studies revealed its structural and morphological details. Crystal identity by powder x‐ray diffraction confirmed the FT‐IR and FT‐Raman spectroscopic techniques as alternate methods for fast analysis of brushite crystals which could form as one type of renal stones. P‐O‐P asymmetric stretchings in both FT‐IR (987.2, 874.1 and 792 cm‐1) and FT‐Raman (986.3 cm‐1, 1057.6 cm‐1 and 875.2 cm‐1) were found as characteristics of brushite crystals. Differential Scanning Calorimetry (DSC) analysis revealed brushite crystallization purity using gel method by studying their endothermic peaks. This study incorporated a multidisciplinary approach in characterizing CHPD crystals grown in vitro to help formulate prevention or dissolution strategy in controlling urinary stone growth. Initial studies with 0.2 M citric acid ions as controlling agent in the nucleation of brushite crystals further support the presented approach. (© 2010 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim) 相似文献
992.
价格低廉的CaO材料在高温下能高效吸附捕集CO2气体,被认为是碳减排的有效方法之一.然而,CaO长时间循环碳酸化/煅烧解吸后,其CO2的化学吸附容量下降,稳定性较差,限制了该材料的工业应用.本文采用天然钙源(牡蛎壳和方解石等)和化学试剂(醋酸钙)为钙基前驱材料制备CaO.采用扫描电子显微镜(SEM),X射线衍射仪(XRD)和氮气吸附仪等手段对制备的CaO材料进行形貌和物理结构的分析表征;在高温和模拟的烟道气氛条件下(10%C02和90%N2),采用热重分析仪测量CaO吸附CO2的能力和长时间循环碳酸化/煅烧解吸后的稳定性.我们经过与目前所报道的其他钙基吸附材料进行比较,并结合钙基前驱材料的市场价格,发现CaO(醋酸钙)的CO2吸附能力和稳定性较为理想,醋酸钙在高温烟气捕碳方面具有非常好的应用前景. 相似文献
993.
A simple and green strategy is reported for the preparation, drug loading, and release properties of a drug delivery system consisting of calcium phosphate (CP) nanocarriers dual‐loaded with bovine serum albumin (BSA) and hydrophobic drug ibuprofen (IBU). The sequential loading of BSA and IBU in calcium phosphate nanocarriers and in vitro simultaneous release of BSA and IBU are realized and investigated. In this method, BSA, which is used as a model protein drug, is encapsulated in situ in calcium phosphate nanocarriers. Subsequently, the typical hydrophobic drug IBU is loaded in the BSA/CP drug delivery system, forming the IBU/BSA/CP dual drug delivery system. The experiments reveal that the preloaded BSA not only reduces the cytotoxicity of calcium phosphate nanocarriers but also significantly improves the IBU drug loading capacity in calcium phosphate nanocarriers and greatly extends the duration of drug release. Thus, the as‐prepared IBU/BSA/CP dual drug delivery system is promising for drug delivery applications. 相似文献
994.
Yasser Saleh Mustafa Alajerami Suhairul Hashim Wan Muhamad Saridan Wan Hassan Ahmad Termizi Ramli Azman Kasim 《Physica B: Condensed Matter》2012,407(13):2398-2403
Several studies showed the interesting properties of trivalent lanthanide ions when doped in various types of glasses. Optical and physical properties of lithium magnesium borate glasses doped with Dy3+ then with Sm3+ ions were determined by measuring their absorption and luminescence spectra in the visible region. The absorption spectra of Dy3+ showed eight absorption bands with hypersensitive transition at 1265 nm (6H15/2→6F11/2-6H9/2) and three PL emission bands at 588 nm (4F9/2→6H15/2), 660 nm (4F9/2→6H13/2) and 775 nm (4F9/2→6H11/2). Regarding the Sm3+, nine absorption bands were observed with hypersensitive transition at 1237 nm (6H5/2–6F7/2); the PL spectrum showed four prominent peaks at 4G5/2→6H5/2 (yellow color), 4G5/2→6H7/2 (bright orange color), 4G5/2→6H9/2 (orange reddish color) and 4G5/2→6H11/2 (red color), respectively. Finally, a series of physical parameters such as the oscillator strengths, refractive index, ions concentration, Polaron radius and other parameters were calculated for each dopant. 相似文献
995.
Droplets of several micrometers in size can be formed in aqueous solution by atomization under ultrasonic irradiation at 2 MHz. This phenomenon, known as atomization, is capable of forming fine droplets for use as a reaction field. This synthetic method is called SARM (sono atomization for reactive mixing). This paper reports on the synthesis of a novel amorphous calcium carbonate formed by SARM. The amorphous calcium carbonate, obtained at a solution concentration of 0.8 mol/dm3, had a specific surface area of 65 m2/g and a composition of CaCO3•0.5H2O as determined using thermogravimetric/differential thermal analysis (TG-DTA). Because the ACC had a lower hydrate composition than conventional amorphous calcium carbonate (ACC), the ACC synthesized in this paper was very stable at room temperature. 相似文献
996.
Xin Liu Wu Li Xueying Nai Shaoju Bian Qingfen Meng Dandan Gao Ming Wei 《Crystal Research and Technology》2012,47(4):455-460
4ZnO·B2O3·H2O whiskers were prepared from 2ZnO·3B2O3·3.5H2O under hydrothermal process at 160 °C for 10 h. The synthesized product was characterized by XRD, SEM, TG‐DSC and FT‐IR. SEM results showed that the synthesized 4ZnO·B2O3·H2O whiskers' length was about 3–10 μm and the diameter was 0.2–0.3 μm. Further study on the whiskers' growth process and mechanism showed that the formation of the whiskers went through three stages and the morphology of 4ZnO·B2O3·H2O changed from irregular particles to rod‐like structures and finally to whiskers. The variation of the morphology of the 4ZnO·B2O3·H2O whisker with the concentration of the starting material was investigated. (© 2012 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim) 相似文献
997.
998.
999.
研究了Ce3+在碱金属-碱土金属硼酸盐体系LiCaBO3,LiSrBO3和LiBaBO3中的光谱特性,发现Ce3+在该体系中均呈现非对称的宽谱发射,对应的发射光谱主峰分别为428,436和440 nm;分别监测三个主发射峰,所得激发光谱主峰分别为364、369和370 nm。研究了电荷补偿剂Li+,Na+,K+对3种材料发射强度的影响,结果显示,材料的发射强度明显提高,其中以掺入Li+时效果最明显。 相似文献
1000.