稻田甲烷排放及其生态效益提高途径的探讨

甲烷被认为是仅次于ＣＯ＿２的具有温室效应的气体．在农业生态系统中，稻田是甲烷的主要来源．讨论稻田甲烷排放量、排放机制，提出减少稻田甲烷排放的控制措施，对控制稻田生态效益提供依据．此外，本文结合稻田生态效益提高途径进行科学认识．     

Hydrolysis kinetics of atrazine and influence factors

ＩｎｔｒｏｄｕｃｔｉｏｎＨｙｄｒｏｌｙｓｉｓｉｓｔｈｅｒｅａｃｔｉｏｎｏｆｃｈｅｍｉｃａｌｓｗｉｔｈｗａｔｅｒａｎｄａｌｓｏａｎｉｍｐｏｒｔａｎｔｅｎｖｉｒｏｎｍｅｎｔａｌｐｒｏｃｅｓｓｏｆｏｒｇａｎｉｃｐｏｌｌｕｔａｎｔｓ.Ｈｙｄｒｏｌｙｓｉｓｏｆｓｙｎｔｈｅｔｉｃｏｒｇａｎｉｃｃｏｍｐｏｕｎｄｓｏｃｃｕｒｓｖｉａｓｅｖｅｒａｌｐａｔｈｗａｙｓｗｈｉｃｈｉｎｖｏｌｖｅｔｈｅｓｐｅｃｉｆｉｃ ａｃｉｄ , ｂａｓｅａｎｄｎｅｕｔｒａｌｐｒｏｃｅｓｓｅｓ.Ｉｎａｄｄｉｔｉｏｎ ,ｗａｔｅｒｄｉｓｓｏｃｉａ…     

广州市机动车排放检测网络化管理若干问题探讨

从分析广州市机动车排放检测技术及其发展状况着手，结合其管理现状，对广州市建设机动车排放检测计算机网络管理系统若干问题进行了探讨。     

淮河流域非木浆制浆造纸业的发展研究

由于淮河流域水环境污染严重，国家已将造纸业特别是小造纸列为淮河流域水环境重点治理对象之一。淮河流域造纸业多为草浆制浆，具有技术，经济与污染治理的特殊性。结合我国造纸工业发展历程和行业现状以及面临的挑战，分析国内及淮河流域制浆造纸业的产业结构，技术结构和环境影响，阐述麦草在我国制浆造纸业中的战略地位，提出淮河流域草浆制浆业的结构重整建议，探讨淮河流域造纸业可持续发展的途径。     

旋揉工艺

介绍了精密旋揉的工艺和设备特点.指出该工艺对减小棒或管状工件断面是经济合理及无屑冷成形方法,在当今金属加工工业中应当受到特别重视.     

Environmental change in Bashang region historical periods

ＩｎｔｒｏｄｕｃｔｉｏｎＴｈｅＢａｓｈａｎｇｒｅｇｉｏｎｉｓｓｉｔｕａｔｅｄａｔｅａｓｔｌｏｎｇｉｔｕｄｅ113°50′-118°00′ａｎｄｎｏｒｔｈｌａｔｉｔｕｄｅ40°58′-42°42′,ｗｉｔｈａｎａｒｅａｏｆ17371ｋｍ2ｆｒｏｍＺｈａｎｇｊｉａｋｏｕｏｆｎｏｒｔｈｅｒｎＨｅｂｅｉｔｏｔｈｅｎｏｒｔｈｏｆＣｈｅｎｇｄｅ.ＴｈｅｒｅｇｉｏｎｌｉｅｓｉｎｔｈｅｍｉｄｄｌｅｓｅｃｔｉｏｎｏｆａｔｒａｎｓｉｔｉｏｎｚｏｎｅｆｒｏｍａｇｒｉｃｕｌｔｕｒａｌｔｏｐａｓｔｏｒａｌｒｅｇｉｏｎｓｏｆｎｏｒｔｈｅｒｎＣｈｉｎａ…     

Prenatal diagnosis of dyssegmental dwarfism

Fetal ultrasound evaluations at 18 weeks gestation on two consecutive pregnancies of a woman who previously gave birth to a stillborn female affected with dyssegmental dwarfism, resulted in accurate diagnoses of unaffected and affected fetuses. Marked disorganization of vertebral bodies and associated encephalocele found in two affected cases in this family are consistent with the original observation of this new syndrome as two major aspects which differentiate it from other forms of lethal dwarfism.     

The enhancement of photodegradation efficiency using Pt–TiO2 catalyst

This study investigates the mechanism of photosensitization and the recombination of excited electron–hole pairs affected by depositing platinum (Pt) on the surface of titanium dioxide (TiO₂). A new catalyst of Pt–TiO₂ was prepared by a photoreduction process. Being model reactions, the photocatalytic oxidation of methylene blue (MB) and methyl orange (MO) in aqueous solutions using the Pt–TiO₂ catalyst was carried out under either UV or visible light irradiation. The experimental results indicate that an optimal content of 0.75%Pt–TiO₂ achieves the best photocatalytic performance of MB and MO degradation and that the Pt–TiO₂ catalyst can be sensitized by visible light. The interaction of Pt and TiO₂ was investigated by means of UV–Vis absorption spectra, photoluminescence emission spectra, and X-ray photoelectron emission spectroscopy. The Pt⁰, Pt²⁺ and Pt⁴⁺ species existing on the surface of Pt–TiO₂, and the Ti³⁺ species existing in its lattice may form a defect energy level. The Pt impurities, including Pt, Pt(OH)₂, and PtO₂, and the defect energy level absorb visible light more efficiently in comparison with the pure TiO₂ and hinder the recombination rate of excited electron–hole pairs.     

Variations in the emissions of volatile organic compounds from the toner for a specific photocopier

A laboratory thermal desorption apparatus was used to measure emissions from a number of nominally identical photocopier toners--manufactured to meet the specifications of one specific model copier--when these toners were heated to fuser temperature (180-200 degrees C). The objective was to assess how potential volatile organic compound (VOC) emissions from the toner for a given copier can vary, depending upon the production run and the supplier. Tests were performed on a series of toner (and associated raw polymer feedstock) samples obtained directly from a toner manufacturer, representing two production runs using a nonvented extrusion process, and on toner cartridges purchased from two local retailers, representing three different production lots (histories unknown). The results showed that the retailer toners consistently had up to 350% higher emissions of some major compounds (expressed as microgram of compound emitted/g of toner), and up to 100% lower emissions of others, relative to the manufacturer toners (p < or = 0.01). The manufacturer toners from one production run had emissions of certain compounds, and of total VOCs, that were modestly higher (13-18%) than those from the other run (p < or = 0.01). The emission differences between the retailer and manufacturer toners are probably due to differences in the manufacturing processes and/or feedstocks used to produce the toners from these different sources.     

Role of amination of a polymeric adsorbent on phenol adsorption from aqueous solution

Adsorption of seven phenols, one aromatic carboxylic acid and one sulfonated aromatic acid from aqueous solution, by a hypercrosslinked polymeric adsorbent (CHA-111) and the derivative animated by dimethylamine was compared. The results of different adsorption isotherms indicated that amino group on the polymeric matrix played a significant role on adsorption of almost all the employed compounds. For most employed compounds adsorption capacities increase to different degree and significantly for those with lower value of pK(a). It may be attributed to the enhanced adsorbent-adsorbate interaction for amino group introduced on the polymeric matrix. The empirical Freundlich isotherm equation was employed to interpret the adsorbent-adsorbate interaction. The adsorption enthalpy change indicated the uptake of phenols on MCH-111 to be an enhanced physical adsorption because of the hydrogen-bonding interaction. Adsorption kinetic study of phenols on CHA-111 and MCH-111 was also conducted and amino group on the matrix will reduce the adsorption rate for change of pore size distribution and loss of macroprous volume as well as the hydration effect on the surface partly.