High Resistive ZnO／Diamond／Si Films Grown via Metal-organic Chemical Vapour Deposition

Piezoelectric ZnO layers with high resistivity for surface acoustic wave applications were prepared on polycrystalline diamond/Si substrates with(Ill) orientation via metal-organic chemical vapour deposition.The characteristics of the films were optimized through different growth methods. The comparative study of the X-ray diffraction spectra and scanning electron microscopic images showed that the final-prepared ZnO films were dominantly c-axis oriented. Zn and O elements in the final prepared ZnO films were investigated through X-ray photoelectron spectroscopy. According to the statistical results, the n(Zn)/n(O) ratio is near 1. The Raman scattering was also performed in back scattering configuration. E2 mode was observed for the final films, which indicated that the better quality ZnO films had been obtained. The resistivity of the films was also enhanced via the modification of the growth methods.     

盲目补锌危害多(二)

体外实验证实，大剂量锌可抑制白细胞的吞噬活力，降低吞噬细胞的杀菌能力，尤其是在体内低钙情况下．这种免疫力下降情况更为明显。因此，低钙者和佝偻病患儿服锌过多，往往由于抵抗力降低而易感染其它疾病。故对患佝偻病的小儿即使检查发现发锌或血锌偏低，也应先治疗佝偻病或在服钙的同时补锌。临床观察发现，一些患缺铁性贫血的小儿在服较大量锌制剂后，贫血症状加重，并对服用铁剂治疗产生了耐药性，     

Theoretical Study on the Catalytic Activity and Sulfur Resistibility of Amorphous Alloy Ni-B-P

In the present paper,one hundred cluster models NinBP (n=1～6) have been designed and studied by density functional theory (DFT) to get an insight into the local structure,catalytic properties and sulfur resistibility of amorphous alloy Ni-B-P. The configurations in triplet state are found more stable than those in the singlet state. It is found that as the content of Ni in the clusters increases,the value of Fermi level in clusters fluctuated,which shows that the content of Ni can influence the Fermi level to a certain extent. Based on the Fermi level and DOS,we consider the activity of catalyst in hydrogenation reaction is the best in cluster Ni3BP. On the basis of the charge of clusters NinBP (n=1～6),we conclude the amorphous alloy Ni-B-P with high Ni content has better sulfur resistibility and the best hydrogenation activity,strong sulfur resistibility appears in clusters Ni3BP,and the amorphous alloy Ni60B20P20 with similar proportion is expected to prepare in the future.     

示差脉冲溶出伏安法测定食盐中痕量铅

铅是一种具有蓄积性、多亲和性的毒物,对人体各组织都有毒性作用,主要损害神经系统、造血系统、消化系统和肾脏,还损害人体的免疫系统,使机体抵抗力下降,因此在环境监测及食品分析中,铅的准确测定受到人们的普遍关注。人类每天要摄入一定量的食盐,如果食盐中的铅含量大于等于 1.0 mg·kg-1,就会对人体产生危害。因此,选择一种简便、灵敏、快速、准确的测铅方法,就显得非常重要。测定铅的方法报道较多的是原子吸收光谱法[1,2],电化学分析法也有报道[3,4],本文研究了用示差脉冲溶出伏安法测定铅[5~9],本法的仪器设备简单、灵敏度高、准确…