Photovoltaic characteristics of phosphorus-doped amorphous carbon films grown by r.f. plasma-enhanced CVD

The phosphorus-doped amorphous carbon (n-C:P) films were grown by r.f. power-assisted plasma-enhanced chemical vapor deposition at room temperature using solid phosphorus target. The influence of phosphorus doping on material properties of n-C:P based on the results of simultaneous characterization are reported. Moreover, the solar cell properties such as series resistance, short circuit current density (J_sc), open circuit current voltage (V_oc), fill factor (FF) and conversion efficiency (η) along with the spectral response are reported for the fabricated carbon based n-C:P/p-Si heterojunction solar cell were measured by standard measurement technique. The cells performances have been given in the dark I–V rectifying curve and I–V working curve under illumination when exposed to AM 1.5 illumination condition (100 mW/cm², 25 °C). The maximum of V_oc and J_sc for the cells are observed to be approximately 236 V and 7.34 mA/cm², respectively for the n-C:P/p-Si cell grown at lower r.f. power of 100 W. The highest η and FF were found to be approximately 0.84% and 49%, respectively. We have observed the rectifying nature of the heterojunction structures is due to the nature of n-C:P films.     

退火温度对高介电常数Ta2O5薄膜电学性能的影响

利用磁控溅射法在硅(Si)衬底上沉积了Ta2O5薄膜,对薄膜进行了不同温度的退火处理,并利用X射线衍射仪对薄膜的微观结构进行了分析.然后在Si的背面和介电薄膜的上面沉积Pt电极,组成了金属—氧化物—半导体( MOS)电容器,对不同温度下退火得到的薄膜制备的MOS电容器的电学性能进行了研究.结果表明,薄膜在700℃开始结...     

Internal reflection ellipsometry for real-time monitoring of polyelectrolyte multilayer growth onto tantalum pentoxide

Internal reflection ellipsometry was used for detection of the consecutive coating of two polyelectrolytes, poly(allylamine hydrochloride) (PAH) and poly(acrylic acid) (PAA), onto a tantalum pentoxide (Ta₂O₅) substrate until the 10th bilayer. The UV patterned PAH-PAA-multilayer was characterized in air via ellipsometry and atomic force microscopy. Suited optical models enabled the determination of the layer thicknesses in wet and dry states. Linear multilayer formation could be proved by Attenuated Total Reflection — Fourier Transformed Infrared Spectroscopy measurements following the increase of the ν(C=O) band depending on the adsorption of the PAA. Streaming potential measurements after each layer deposition step indicated a change in surface charge after each layer deposition due to the consecutive coating of PAH and PAA. In this article the internal reflection ellipsometry is shown to be a convenient possibility to analyze the modification of a thin transparent Ta₂O₅ substrate.     

The arsenic for phosphorus swap is accidental, rather than a facultative one, and the question whether arsenic is nonessential or toxic is quantitative, not a qualitative one

Arsenic shares many physicochemical properties with phosphorus, so that arsenic can be taken up inadvertently by cells through the pathways for phosphorus. As a phosphate analog, arsenate competes with phosphate and enters cells via phosphate transporters. In the cell, arsenate can be recognized as a substrate by enzymes that usually use phosphate as a substrate. The phosphate for arsenate swap results in wasteful ‘futile cycles’ in metabolic pathways, uncoupled oxidative phosphorylation and extreme DNA instability. The disrupting metabolic effects of arsenic have an evolutionary meaning, so that all living organisms—from chemoautotrophic organisms that grow by reducing or oxidizing arsenic to metazoan—carry highly conserved arsenic resistance genes. Arsenic resistance can result from different strategies including selective transport to maximize phosphate uptake and minimize entry of arsenate, active transport to export arsenate, arsenic storage in specialized compartments, enzyme selectivity toward phosphate, and increased efficiency of DNA repair systems. None of these strategies is infallible, though, and susceptibility to arsenic toxicity varies between taxa in many orders of magnitude. Even arsenic-hypertolerant organisms will stop to grow and will eventually die when exposed to arsenic over species-specific resistance limits. The arsenic for phosphorus swap is an accidental one, it does not warrant a conclusion in favor of the essentiality of arsenic to life as we know it.     

脂肪醇聚氧乙烯醚磷酸酯的合成

以脂肪醇聚氧乙烯醚(AEO-3)为原料,P2O5为磷酸化试剂,经酯化、水解合成脂肪醇聚氧乙烯醚磷酸酯.考察了P2O5加入方式、原料配比、酯化时间、酯化温度对反应的影响.     

三聚氰胺甲醛树脂包覆不同目数红磷的稳定化研究

采用原位聚合方法制备了三聚氰胺甲醛树脂包覆不同目数的红磷.对包覆红磷进行了扫描电镜、X射线光电子能谱(XPS)、吸水性、抗氧化性、pH值及热重分析测试.扫描电镜和XPS结果表明,三聚氰胺甲醛树脂在红磷表面形成了有效包覆.吸水率结果表明,三聚氰胺甲醛树脂包覆后的红磷,其吸水率随着时间增长显著降低,7d后的吸水率低于0.6...     

某硅钙质胶磷矿正反浮选实验研究

这是一篇矿物加工工程领域的论文。采用超细粉磨技术处理磷矿,可改变磷矿中含磷矿物的物理化学性质,从而提高磷矿中磷的溶解与释放,使其可作为磷肥使用。搅拌磨机作为超细粉磨设备,用其处理磷矿的可行性与工艺参数对磨矿效果影响的研究尚不完善。本文采用立式搅拌磨机对河北某磷矿进行湿法磨矿实验,粉磨产品的粒度分布通过NKT6100-D型激光粒度仪进行检测,探究磨矿工艺参数对产品粒度组成以及新生成粒级含量的影响,并通过R-R方程将产品粒度参数化分析,确定较适宜的工艺参数。结果表明,在搅拌器转速550 r/min、磨矿浓度65%、充填率60%、料球比0.5和磨矿时间30 min的条件下,获得有效磷含量和枸溶率分别为8.75%和74.03%,颗粒特征参数b为0.371、均匀性系数n为1.426的粉磨产品,可见用搅拌磨机对磷矿进行超细粉磨处理是可行的。     

On the issue of limiting nutrient and predictions of cyanobacteria in aquatic systems

This study aims at bridging the gap between freshwater and marine eutrophication studies by presenting (1) a cross-system analysis of the relationship between chlorophyll and the total nitrogen (TN) to total phosphorus (TP) ratio (2) a general model to predict concentrations of cyanobacteria from data on TP, the TN/TP ratio, salinity and temperature, and (3) a general trophic level classification for aquatic systems based on chlorophyll classes (for oligo-, meso-, eu- and hypertrophic systems). The data compiled in this study concerns more than 500 lakes and coastal areas covering a very wide domain in terms of nutrient concentrations and salinity. There was no simple relationship between the TN/TP ratio and empirical chlorophyll concentrations or concentrations of cyanobacteria. Variations in TP rather than TN generally seem to be more important to predict variations among systems in chlorophyll-a and cyanobacteria. Different "bioavailable" forms of the nutrients (DIN, DIP, phosphate, nitrate, etc.) have been shown to have very high coefficients of variation (CV), which means that many samples are needed to obtain reliable empirical data which are necessary in models aiming for high predictive power and practical usefulness.     

Nb2O5掺杂对BaTiO3基介电陶瓷瓷料性能的影响

研究了Nb2O5掺杂对细晶BaTiO3陶瓷的微观形貌和介电性能的影响,并利用XRD、SEM对掺杂后陶瓷的相组成和微观形貌进行了表征.实验表明:掺杂2%(质量分数)Nb2O5的试样达到最优的性能(ε25℃=1 395,αε=4%),满足X8R特性;XR.D分析表明,Nb5+取代B位形成了固溶体-BaNb0.5Ti0.5O...     

Phosphorus removal by adsorbent based on poly-aluminum chloride sludge

Phosphorus adsorption tests were carried out using poly-aluminum chloride sludge (PACS), which was collected from a water treatment plant in Nanjing. The amount of phosphorus adsorbed by PACS increased quickly within the first hour and reached equilibrium after about 48 h. The adsorption behavior of PACS for phosphorus is consistent with the Langmuir adsorption isotherm equation (R² > 0.99) and parallel first-order kinetic equation (R² > 0.98). With the increase of the PACS concentration, the adsorption capacity of PACS for phosphorus decreased, and the removal rate increased. The results of batch tests showed that the adsorption capacities of PACS for phosphorus ranged from 1.64 to 1.13 mg/g when the pH value varied from 4 to 10. However, the adsorption capacity of PACS was not evidently influenced by temperature. In comparison with the ion exchange resin, the adsorption capacity of PACS was barely inhibited by competitive ions, such as ${\text{SO}}_4^{2-}$, ${\text{NO}}_3^{-}$, and Cl⁻. The PACS surface after adsorption became smooth, and the vibration peaks of Al–O and Al–OH shifted. Both HCl and NaOH have a strong desorption effect on PACS after adsorption saturation, and with higher concentrations of HCl and NaOH, the desorption effect was stronger. Results of column adsorption experiments showed that with lower phosphorus and hydraulic loads, the adsorption column took longer to reach saturation. This indicated that PACS could be used as an efficient material for removal of phosphorus from water. This study provides a new treatment method with PACS.