对总磷快速测定的研究

本文通过采用COD消解加热器消解,相对于传统的检测总磷的方法来说,建立了快速测定水中总磷的分析方法。通过对本法的多次实验的结果分析,并与标准方法所得到的结果进行比较分析得出了COD消解加热器消解测定总磷的方法是一种耗时少、具有较高准确度和精密度等优点的检测总磷方法。     

探究地表水总磷测定与浊度干扰去除的方法

地表水总磷测定属于水质监测的重要参数,但实际地表水总磷测定期间会因为水体浑浊度影响到实际检测结果,致使检测结果出现偏差。为保证地表水总磷测定结果的可靠性,需要去除浊度干扰,对此,该文主要分析地表水总磷测定与浊度干扰去除方法,结合项目案例,从监测指标、总磷测定方案、浊度去除实验及操作要点、统计方法与结果分析等方面予以分析,保证了地表水总磷测定的准确性与可靠性。     

总磷分析仪校准方法研究

总磷分析仪是一种用于测量水中总磷的工作计量器具。为解决其量值溯源问题,本文从温度示值误差和温场均匀性、消解时间示值误差、示值误差、示值重复性、零点漂移、仪器稳定性等6个校准参量较为全面地提出了总磷分析仪的校准方法。同时,通过样机试验,探究各参量校准方法的可行性,为校准机构或企事业单位总磷分析仪的校准提供了参考。     

钼酸铵分光光度法测定水中总磷不确定度

以某污水处理厂处理设施的出水为待测水样,运用测定不确定度评定的基本方法和程序,分析影响钼酸铵分光光度法测定水中总磷的不确定度的各种因素,建立数学模型,分析不确定度来源,计算总磷的合成不确定度。按照总磷测定的方法原理逐项分析引起实验不确定度的原因,计算各步引入的不确定度,总结出总磷测定过程中引入不确定度的规律,找出影响不确定度的重要环节。     

离子色谱法测定地表水中总磷

为建立测定地表水中总磷的离子色谱法,采用碱性过硫酸钾消解地表水样,OnGuard Ⅱ Ba柱过滤去除消解液中大量硫酸盐,离子色谱法测定总磷含量。对实际水样进行分析,总磷的加标回收率为94.6%~105.7%。该方法测定结果准确,具有一定的应用价值。     

分光光度法测定固体废弃物中的总磷含量

分光光度法具有分析成本低、测试简单、实验过程稳定、数据结果准确的优点，非常适合固体废弃物总磷含量的测定，本文通过具体实验步骤及实验数据，详细介绍了分光光度法的测定流程，以作为测定固体废弃中总磷含量方法研究的参考。     

总磷测定中标准曲线与工作曲线的比较

通过对钼锑抗分光光度法测定总磷的标准曲线和工作曲线的比较试验,并应用数理统计方法对结果加以分析,证明总磷测定中标准曲线与工作曲线无显著性差异(显著性水平为0.05,样本数为6),且两者具有相似的精密度和准确度。     

地表水总磷测定法优化及其有关问题的探讨

本文根据国标法过硫酸钾消解钼酸铵分光光度法（GB／T11893～1989）存在的一些普遍问题,结合在工作中总结出的方法借用COD消解思路优化、建立快速测定地表水水质总磷国标分析方法,通过对本法从测定条件、准确度、精密度等方面多次实验,并与标准方法进行比较分析结果,同时对优化国标方法测总磷应注意有关问题进行了探讨。     

四气体汽车尾气分析仪的研制与开发

本介绍了Bantam2000四气体汽车尾气分析仪的工作原理、功能特点以及实现方法，并着重阐述了电化学传感器的输出特性及其在仪器中的具体应用和仪器空燃比的测量等。     

总磷总氮水质在线分析仪计量检定的现状分析

本文主要介绍了总磷总氮水质在线分析仪的测量原理和使用现状,对总磷总氮水质在线分析仪进行计量检定的必要性,分析了在计量检定过程中影响检定结果的主要因素,并探讨了总磷总氮水质在线分析仪的相关检定事宜.     

单层黑磷和蓝磷扩展分子结的电子输运特性

本工作应用非平衡格林函数理论和密度泛函理论研究了二维材料单层黑磷扩展分子结和蓝磷扩展分子结的电子输运特性,以及在应力作用下能隙和伏安特性的变化特点。结果发现,两种扩展分子结在发生应变(拉伸和压缩)过程中,随着应变(拉伸和压缩)的增加,HOMO能量和LUMO能量逐步靠近,导致能隙逐渐降低,分别减小了0.67eV和1.33eV。能隙降低,同时导通轨道间隔和导通轨道迁移率也降低,导致伏安特性曲线中量子化台阶逐渐消失,出现了类似金属的I-V曲线特点。此外,单层黑磷扩展分子结在0.75~2.00V范围内产生稳定电流,有望应用于电路中的稳流装置。     

云南磷深加工现状与展望

结合云南黄磷、湿法磷酸以及磷深加工业的现状,分析展望云南磷深加工的发展趋势和前景。由于科技进步、应用开发、市场拓展、政策法规等诸多因素,磷深加工这一具有发展前景的工业尚需经历一个“量变到质变”的发展过程。     

Wavelength-Tunable Mid-Infrared Lasing from Black Phosphorus Nanosheets

Van der Waals layered semiconductor materials own unique physical properties and have attracted intense interest in developing high-performance electronic and photonic devices. Among them, black phosphorus (BP) is distinct for its layer number-tuned direct band gap which spans from near- to mid-infrared (MIR) waveband. In addition, the puckered honey comb crystal lattice endows the material with highly linear-polarized emission and marked anisotropy in carrier transportation. These unique material properties render BP as an intriguing and promising building block for constructing mid-infrared-ranged coherent light sources. Here, a room temperature surface-emitting MIR laser based on single crystalline BP nanosheets coupled with a distributed Bragg reflector cavity is reported. MIR stimulated emission at 3611 nm is achieved with a near-unity linear polarization, which exhibits robust thermal stability up to 360 K. Most importantly, the lasing wavelength can be tuned from 3425 to 4068 nm by varying the cavity length via thickness control of BP layer. The demonstrated highly polarized lasing output and wavelength-tunable capacity of the proposed device scheme in MIR spectral range opens up promising opportunities for a broad array of applications in polarization-resolved IR imaging, range-finding, and free space quantum communications.     

Synthesis of Crystalline Black Phosphorus Thin Film on Sapphire

Black phosphorus (BP) has recently attracted significant attention due to its exceptional physical properties. Currently, high‐quality few‐layer and thin‐film BP are produced primarily by mechanical exfoliation, limiting their potential in future applications. Here, the synthesis of highly crystalline thin‐film BP on 5 mm sapphire substrates by conversion from red to black phosphorus at 700 °C and 1.5 GPa is demonstrated. The synthesized ≈50 nm thick BP thin films are polycrystalline with a crystal domain size ranging from 40 to 70 µm long, as indicated by Raman mapping and infrared extinction spectroscopy. At room temperature, field‐effect mobility of the synthesized BP thin film is found to be around 160 cm² V^?1 s^?1 along armchair direction and reaches up to about 200 cm² V^?1 s^?1 at around 90 K. Moreover, red phosphorus (RP) covered by exfoliated hexagonal boron nitride (hBN) before conversion shows atomically sharp hBN/BP interface and perfectly layered BP after the conversion. This demonstration represents a critical step toward the future realization of large scale, high‐quality BP devices and circuits.     

Growth of Black Phosphorus Nanobelts and Microbelts

Black phosphorus nanobelts are fabricated with a one‐step solid–liquid–solid reaction method under ambient pressure, where red phosphorus is used as the precursor instead of white phosphorus. The thickness of the as‐fabricated nanobelts ranges from micrometers to tens of nanometers as studied by scanning electron microscopy. Energy dispersive X‐ray spectroscopy and X‐ray diffraction indicate that the nanobelts have the composition and the structure of black phosphorus, transmission electron microscopy reveals a typical layered structure stacked along the b‐axis, and scanning transmission electron microscopy with energy dispersive X‐ray spectroscopy analysis demonstrates the doping of bismuth into the black phosphorus structure. The nanobelt can be directly measured in scanning tunneling microscopy in ambient conditions.     

多晶硅冶金法除磷的研究进展

磷是多晶硅中的一种主要杂质元素,目前国内外采用冶金法除磷的工艺主要包括酸洗除磷、合金定向凝固除磷和真空除磷工艺.其中,酸洗除磷工艺可以很有效地去除磷杂质,但仍未达到太阳能级多晶硅小于0.1×10-4%(质量分数)的要求.采用合金定向凝固工艺可以去除80%以上的磷杂质,但目前对凝固后硅中残留溶剂金属的去除方法还有待进一步的研究.通过真空感应熔炼实验已将磷含量从15×10-4%(质量分数)降低至0.8×10-5%(质量分数),并对除磷的热力学条件进行了初步探索.     

泥磷的处理方法研究

针对当前泥磷处理方法单一、污染严重的现状,分析比较了几种泥磷处理方法的优缺点,提出了经济有利和环境友好的从泥磷中制取次磷酸钠的方法.     

Black Phosphorus Nanosheets Passivation Using a Tripeptide

In the past several years, 2D black phosphorus (BP) has captured the research community's interest because of its unique electronic, photonic, and mechanical properties. However, the intrinsic instability of BP limits its preservation and practical application. Despite kinds of BP passivation strategies being well‐documented, the use of metal ligand coordination or polymer modification may have potential long‐term detrimental effects on human bodies. Here, a tailored tripeptide Fmoc‐Lys‐Lys‐Phe (Fmoc‐KKF) is synthesized for surface modification of BP nanosheets. Compared with bare BP with rapid degradation, the BP@FKK complex exhibits excellent stability, thereby significantly increasing the life span. Significantly, the BP@FKK shows favorable cell compatibility and enhanced cellular uptake compared to the bare BP.     

钒铁中磷的分析方法改进

本文针对现有国标分析方法 GB/T 8704.7-2009钼蓝光度法测定钒铁中的磷含量方法存在操作繁琐、流程长、重现性差,准确度低、成本较高等问题进行了改进。通过采用硫酸加硝酸溶样,用亚硫酸钠还原钒为统一的4价,采用对应试液作参比消除钒的干扰等手段,使钒铁中磷的含量的测定方法变得操作简便、快速、准确、成本下降。