基于高光谱的苹果树冠层磷素状况估测模型研究

利用高光谱技术估测了苹果树冠层的磷素含量。先用ASD Field Spec3型地物光谱仪测定了春梢停止生长期苹果树冠层的高光谱反射率,并对光谱数据进行了多种变换处理。然后对其与磷素含量进行了相关分析,找出了与磷素相关性较显著的光谱参量,并通过逐步回归分析建立了磷素估测模型。结果表明,近红外波段是苹果树冠层磷素的敏感波段;808 nm、921 nm、1195 nm、1272 nm及其组合的归一化红外光谱指数与苹果树冠层磷素高度相关。在构建的估测模型中,以808 nm、921 nm、1195nm、1272 nm及其组合的归一化红外光谱指数为自变量构建的高光谱估测模型的估测效果最佳。该研究实现了苹果树冠层磷素含量的快速估测,同时也为苹果的实时营养诊断提供了理论依据。     

Black phosphorus junctions and their electrical and optoelectronic applications

Black phosphorus(BP),an emerging two-dimensional material,is considered a promising candidate for next-genera-tion electronic and optoelectronic devices due to in-plane anisotropy,high mobility,and direct bandgap.However,BP devices face challenges due to their limited stability,photo-response speed,and detection range.To enhance BP with powerful electric-al and optical performance,the BP heterostructures can be created.In this review,the state-of-the-art heterostructures and their electrical and optoelectronic applications based on black phosphorus are discussed.Five parts introduce the perform-ance of BP-based devices,including black phosphorus sandwich structure by hBN with better stability and higher mobility,black phosphorus homojunction by dual-gate structure for optical applications,black phosphorus heterojunction with other 2D materials for faster photo-detection,black phosphorus heterojunction integration with 3D bulk material,and BP via As-doping tunable bandgap enabling photo-detection up to 8.2 μm.Finally,we discuss the challenges and prospects for BP electric-al and optical devices and applications.     

Ga、P改性对辛烷值助剂芳构化性能的影响

采用金属Ga以及P元素对辛烷值助剂进行改性,并采用一系列方法对催化剂进行表征,同时采用固定流化床装置对催化剂进行性能评价,考察金属Ga以及P元素对催化剂物化性质和对汽油芳烃选择性的影响。结果表明：采用金属Ga改性催化剂后,可以提高催化剂的芳构化能力,有利于汽油辛烷值的提高;在金属Ga改性催化剂中再引入P元素后,P与金属Ga发生相互作用,减弱了催化剂的芳构化能力,但是催化剂B酸中心增加,有利于提高产物的低碳烯烃选择性。     

磷石膏水洗液中磷、氟、有机物的去除

研究了煤质炭、果壳炭和秸秆灰三种吸附材料对模拟溶液中磷、氟、有机物的去除效果,并进行了磷石膏水洗液中多种污染物同步去除研究。结果表明：三种吸附材料对磷和氟的去除效果为秸秆灰>煤质炭>果壳炭,对有机物的去除效果为煤质炭>秸秆灰>果壳炭,强酸条件有利于磷和氟的去除,但对有机物去除影响不大。秸秆灰对磷、氟和煤质炭对有机物的吸附过程均符合二级动力学模型和Langmuir模型,其理论最大吸附量分别为磷88.20 mg/g、氟63.98 mg/g、有机物131.32 mg/g。120 g/L秸秆灰与50 g/L煤质炭同时投加至磷石膏水洗液中反应120 min后,污染物剩余浓度为磷9.57 mg/L、氟12.88 mg/L、有机物31.86 mg/L,反应后pH为8.95,满足《磷肥工业水污染物排放标准》（GB 15580—2011）要求。秸秆灰对溶液中磷、氟等阴离子的去除机理为静电吸附和化学沉淀,煤质炭对溶液中有机物的去除机理为离子交换和物理吸附。     

METABOLIC RESPONSES OF BAKER'S YEAST TO GLUCOSE ADDITION DURING AEROBIC STARVATION

The kinetics and extent of glucose uptake, ethanol and acetate production, glucose-induced medium acidification and endogenous respiration were studied in baker's yeast starved aerobically for 0, 28, 54 and 96 h in saline (9 g litre^?1 NaCI) at 35°C. Except for the last interval, prolonged starvation brought about an overall increase in most parameters; the transient increase in endogenous respiration observed after glucose addition was lowered with proceeding starvation. A 96 h starvation brought about a change in the kinetics of ethanol production, sharp increase in acetate production and a strong reduction of both the extent and the rate of glucose-induced acidification and of endogenous metabolism.     

Mechanism of cellular uptake of graphene oxide studied by surface-enhanced Raman spectroscopy

The last few years have witnessed rapid development of biological and medical applications of graphene oxide (GO), such as drug/gene delivery, biosensing, and bioimaging. However, little is known about the cellular uptake mechanism and pathway of GO. In this work, surface-enhanced Raman scattering (SERS) spectroscopy is employed to investigate the cellular internalization of GO loaded with Au nanoparticles (NPs) by Ca Ski cells. The presence of Au NPs on the surface of GO enables detection of enhanced intrinsic Raman signals of GO inside the cell. The SERS results reveal that GO is distributed inhomogeneously inside the cell. Furthermore, internalization of Au-GO into Ca Ski cells is mainly via clathrin-mediated endocytosis, and is an energy-dependent process.     

Facile synthesis of black phosphorus directly grown on carbon paper as an efficient OER Electrocatalyst: Role of Interfacial charge transfer and induced local charge distribution

Black phosphorus (BP), as a new 2D material, is normally synthesized by a high-pressure and high-temperature (HPHT) method from white and red phosphorus, which severely hinders the further development of BP for any potential applications and leads to search for other potential applications of BP with big challenge. Herein, we develop a facile and efficient Thermal-Vaporization-Transformation (TVT) approach to prepare a highly active BP directly grown on carbon paper as the electrode for Oxygen evolution reaction (OER), showing a low onset potential of 1.45 V versus RHE. Simultaneously, the current density of BP-CP illustrates the excellent electro-catalysis stability only decreases by 3.4% after continuous operation for 10000 s. Meanwhile, the density functional theory (DFT) calculations further illustrates the P-doped carbon layer in the upper side of BP layer is actually responsible for its enhanced OER property, and the adjacent carbon atoms of the embedded P atoms are actually the active sites due to the induced local change distribution by intramolecular change transfer. Considering the facile, but efficient and scalable, TVT approach can directly synthesize BP-CP with excellent OER performance, which is promising for BP electrocatalysts used for OER in metal-air batteries, fuel cells, water-splitting devices, even other key renewable energy.     

大直径重掺硅单晶工艺研究

重掺单晶一些独有的特性,能有效解决目前集成电路面临的一些难题。对大直径重掺硅单晶生长过程中的一些工艺进行了研究,主要包括掺杂方式和拉速设定两个方面,通过实验分析,选取了适宜的掺杂方式与拉速,最终生长出外形良好,符合电阻率目标要求的单晶。     

工业磷化废水处理的实验研究及应用

文章介绍了目前工业磷化废水处理过程中常用的化学沉淀除磷法,研究了pH、PAM投加量的变化对除磷效率的影响。确定了除磷的最佳工艺条件为:pH为7.5~9之间,PAM投加量为300 mg/L。