K_2CO_3活化制备花椒籽废渣的活性炭及其对对硝基苯酚的吸附性能

采用花椒籽废渣(RPS)为原料,K_2CO_3为活化剂制备了花椒籽废渣活性炭(KAC),以期实现农业废弃物的再利用。采用傅里叶变换红外光谱仪(FTIR)、扫描电子显微镜(SEM)、热重分析仪(TGA)、能量散射光谱(EDS)、X射线衍射仪(XRD)和气体吸附法等技术手段对其进行表征。分析了浸渍比(m(K_2CO_3)∶m(RPS))、浸渍时间、活化温度和活化时间对制备花椒籽废渣活性炭的影响,并且测试了花椒籽废渣活性炭对对硝基苯酚的吸附行为。研究结果表明,在浸渍比为0.8,浸渍时间为12 h,活化温度为550℃,活化时间为60min的条件下,活性炭的产率为29.3%,比表面积为1210 m~2/g,碘值为1002 mg/g,对亚甲基蓝的平衡吸附容量为362 mg/g,灰分为2.2%,水分为6.6%。对对硝基苯酚的吸附性能研究表明,293 K,pH=8.0,吸附180min后可达到吸附平衡,对硝基苯酚的吸附容量为406 mg/g,吸附可用Langmuir等温方程较好模拟,吸附为自发的放热过程。动力学研究表明该吸附符合准二级动力学模型。K_2CO_3活化法制备花椒籽废渣活性炭原料廉价,工艺简单,制得的活性炭吸附性能优异,具有较好的应用前景。     

Alumina supported synthesis of Cassia marginata gum‐g‐poly(acrylonitrile) under microwave irradiation

In view of the known advantages of the microwave promoted reactions done in dry medium, the seed gum sourced from Cassia marginata has been graft copolymerized with acrylonitrile in dry medium at neutral alumina support under microwave irradiation. Grafting conditions were optimized and the representative graft copolymer was characterized by Fourier transform‐infrared, Thermo gravimetric analysis, Scanning electron microscopy, and X‐Ray Diffraction (XRD) measurement, taking Cassia marginata gum (CM) as reference. Much higher % grafting and % efficiency could be obtained in the microwave promoted alumina supported grafting as compared to grafting done in aqueous medium (microwave promoted and conventional). Properties of the microwave synthesized Cassia marginata gum‐graft‐poly(acrylonitrile) (CM‐g‐PAN) were studied and compared with the parent seed gum. © 2007 John Wiley & Sons, Ltd.     

Die Lagerung von radioaktiven Stoffen

P³² and C¹⁴ have been used together to identify and tgrace the photosynthates of Zea mays during the seedling stage. By this double labelling technique and single labelling with C¹⁴O₂ and H₃P³²O₄, carbohydrates, amino acids, and phosphoproteins were identified on paper chromatograms. Tables and figures summarise the results obtained under different mineral deficiency. These results indicate the effects of the absence of P, Mg, K, N, Ca, and trace elements on both respiration and photosynthesis.     

Relationships between Nitrogen Translocation and Accumulation in Growing Plant Parts of Grain Legumes

Abstract

Grain legumes absorbed mineral ¹⁵N at every stage of development and transported it directedly (just as symbiotically fixed ¹⁵N₂) into the plant parts growing at the respective stage. The ¹⁵N accumulation in the grains after long-lasting ¹⁵N supply can be ascribed, for the major part, to a secondary ¹⁵N translocation after a temporary incorporation into older plant parts (leaves, stem). Inhibition experiments with antibiotics revealed no direct relation between the accumulation of amino acid ¹⁵N in growing pods and seeds and the protein synthesis in this target organs. It may include, however, processes of (active ?) uptake and transport with a possible contribution of carrier systems specific for distinct amino acids.     

自然老化谷类种子的二维红外光谱研究

种粮老化影响种子活力及粮食品质。利用傅里叶变换红外光谱(FT-IR),二阶导数红外光谱(SD-IR)和二维相关红外光谱(2D-IR)方法对不同储藏年份的大麦,小麦,稻谷,玉米和高粱种子进行区分研究。结果显示,原始光谱中几个峰强比有差异;在二阶导数红外光谱中,不同储藏年份种子在1 800～800 cm-1范围内的吸收峰强度和形状显示出差异。二维相关红外光谱结果显示：大麦在1 350～1 800 cm-1,小麦,稻谷,玉米和高粱在860～1 690 cm-1范围内有明显差异,随储藏年份增加,自动峰和交叉峰的数目减少,强度减弱。结果表明,应用傅里叶变换红外光谱结合二维相关红外光谱能有效快速地区分不同储藏年份的谷类种子。     

Synthesis of a Au‐on‐Pd Heteronanostructure Stabilized by Citrate and its Catalytic Application

The preparation of Au‐on‐Pd heteronanostructure (HNS) using citrate‐stabilized polycrystalline Pd nanoparticles (NPs) as the seeds is described. The resulting Au‐on‐Pd HNS is characterized and it is found that the formation of Au‐on‐Pd HNS depends greatly on a ratio between Pd seeds and AuCl₄^? ions added and the optimal molar ratio is 10:1. If fewer AuCl₄^? ions are added (Pd/Au ratio is 100:1), the growth of Au NPs only occurs on part of the Pd seeds’ surface. The addition of more AuCl₄^? ions (Pd/Au ratio is 5:1) hinders the growth of Au NPs on the Pd seeds’ surface. To demonstrate the catalytic performance, the electrochemistry oxidation of ethanol and the reduction of p‐nitrophenol by NaBH₄ are chosen to examine the catalytic activity of Au‐on‐Pd HNS. Pd seeds, Au NPs, and poly(vinyl pyrrolidone) (PVP)‐stabilized PdAu nanoalloy are used as the references for comparison. In the first reaction, the catalytic reactivity of Au‐on‐Pd HNS is better than that of corresponding pure Pd or Au NPs, while the opposite occurs for the latter reaction. The catalytic activity of Au‐on‐Pd HNS is much higher than that of PVP‐stabilized PdAu nanoalloy.     

Ferromagnetic seeding for the magnetic targeting of drugs and radiation in capillary beds

A new implant assisted-magnetic drug targeting approach is introduced and theoretically analyzed to demonstrate its feasibility. This approach uses ferromagnetic particles as seeds for collecting magnetic drug carrier particles at the desired site in the body, such as in a capillary bed near a tumor. Based on the capture cross section (λ_c) approach, a parametric study was carried out using a 2-D mathematical model to reveal the effects of the magnetic field strength (μ₀H₀=0.01–1.0 T), magnetic drug carrier particle radius (R_p=20–500 nm), magnetic drug carrier particle ferromagnetic material content (x_fm,p=20–80 wt%), average blood velocity (u_B=0.05–1.0 cm/s), seed radius (R_s=100–2000 nm), number of seeds (N_s=1–8), seed separation (h=0–8R_s), and magnetic drug carrier particle and seed ferromagnetic material saturation magnetizations (iron, SS 409, magnetite, and SS 304) on the performance of the system. Increasing the magnetic field strength, magnetic drug carrier particle size, seed size, magnetic drug carrier particle ferromagnetic material content, or magnetic drug carrier particle or seed saturation magnetization, all positively and significantly affected λ_c, while increasing the average blood velocity adversely affected it. Increasing the number of seeds or decreasing the seed separation, with both causing less significant increases in λ_c, verified that cooperative magnetic effects exist between the seeds that enhance the performance. Overall, these theoretical results were encouraging as they showed the viability of this minimally invasive, implant assisted-magnetic drug targeting approach for targeting drugs or radiation in capillary beds.     

新疆十字花科部分杂草种于微形态的研究

本文对新疆的十字花科9属9种杂草种子形状、大小、颜色及内部特征进行了描述，对种子外形、种皮进行电镜扫描，发现种皮微形态特征在种与种之间有明显的差异，并根据种皮微形态特征编制了分种检索表．     

A new flavonoid glucoside from Cassia angustifolia

A new flavonoid glucoside with a known one was isolated from the leaves of Cassia angustifolia.Based on the spectral analysis, including MS,~1H NMR,~(13)C NMR,DEPT,~1H-~1HCOSY,HMQC,HMBC and NOSEY,their chemical structures were determined as kaempferol-3-O-[(6′′′-O-trans-sinnapoyl)-β-D-glucopyranosyl(1→)]-β-D-glucopyranoside 1 and apigenin-6,8-di-C-glycoside 2.