沼液复合型杀虫剂的田间应用试验研究

通过沼液复合型杀虫剂的田间应用试验,对各种沼液复合型杀虫剂的抗病防虫性能进行了深入研究.在大田应用条件下测试了沼液复合型杀虫剂的杀虫效果.结果表明,该沼液复合型杀虫剂对蚜虫的毒杀作用均比较明显.为了推进沼液复合型杀虫剂的商业化进程,提出便于其田间应用的各种最佳配比浓度,即BP01号、BP02号、BP03号、BP04号、BP05号沼液复合型杀虫剂抗病防虫性能最佳的配比分别为9 500倍液、26000倍液、11 667倍液、22 000倍液和13 333倍液.     

Daytime light intensity affects seasonal timing via changes in the nocturnal melatonin levels

Daytime light intensity can affect the photoperiodic regulation of the reproductive cycle in birds. The actual way by which light intensity information is transduced is, however, unknown. We postulate that transduction of the light intensity information is mediated by changes in the pattern of melatonin secretion. This study, therefore, investigated the effects of high and low daytime light intensities on the daily melatonin rhythm of Afro-tropical stonechats (Saxicola torquata axillaris) in which seasonal changes in daytime light intensity act as a zeitgeber of the circannual rhythms controlling annual reproduction and molt. Stonechats were subjected to light conditions simulated as closely as possible to native conditions near the equator. Photoperiod was held constant at 12.25 h of light and 11.75 h of darkness per day. At intervals of 2.5 to 3.5 weeks, daytime light intensity was changed from bright (12,000 lux at one and 2,000 lux at the other perch) to dim (1,600 lux at one and 250 lux at the other perch) and back to the original bright light. Daily plasma melatonin profiles showed that they were linked with changes in daytime light intensity: Nighttime peak and total nocturnal levels were altered when transitions between light conditions were made, and these changes were significant when light intensity was changed from dim to bright. We suggest that daytime light intensity could affect seasonal timing via changes in melatonin profiles. Professor Dr. E. Gwinner died on 07 September 2004.     

Kinetics of selective catalytic reduction of NO by NH3 on Fe-Mo/ZSM-5 catalyst

The catalyst of Fe-Mo/ZSM-5 has been found to be more active than Fe-ZSM-5 and Mo/ZSM-5 separately for selective catalytic reduction (SCR) of nitric oxide (NO) with NH3. The kinetics of the SCR reaction in the presence of O2 was studied in this work. The results show that the observed reaction orders were 0.74-0.99, 0.01-0.13, and 0 for NO, O2 and NH3, respectively, at 350-450℃. And the apparent activation energy of the SCR was 65 kJ/mol on the Fe-Mo/ZSM-5 catalyst. The SCR mechanism was also deduced. Adsorbed NO species can react directly with adsorbed ammonia species on the active sites to form N2 and H2O. Gaseous O2 might serve as a reoxidizing agent for the active sites that have undergone reduction in the SCR process. It is also important to note that a certain amount of NO was decomposed directly over the Fe-Mo/ZSM-5 catalyst in the absence of NH3.     

An environmental impact assessment of quantum dot photovoltaics (QDPV) from raw material acquisition through use

Some emerging technologies are expected to be pivotal for solving many of the environmental challenges faced today, especially those related to energy. However, many of these technologies may incur significant environmental impacts over their life cycle, while having environmental benefits during their use. This paper presents results of a Life Cycle Assessment (LCA) of a proposed type of nanophotovoltaic, quantum dot photovoltaic (QDPV) module. The LCA is confined to the stages of raw materials acquisition, manufacturing, and use. The impacts of QDPV are compared with other types of PV modules and energy sources - both renewable and nonrenewable. To provide a comprehensive comparative assessment, QDPV modules were compared with mature as well as emerging PV types for which data are available. Comparative assessment with other types of energy sources includes coal, oil, lignite, natural gas, diesel, nuclear, wind, and hydropower.QDPV modules may have the potential to overcome two current barriers of solar technology: low efficiencies and high manufacturing costs. If higher efficiencies are realized, QDPV modules could pave the way to large scale implementation of solar energy, helping nations move toward greater energy independence. On the other hand, candidate materials as quantum dots for solar cell applications are mostly compound semiconductors such as cadmium selenide, cadmium telluride, and lead sulfide which may be toxic and for which renewable options are limited. Toxic effects of these materials may be exacerbated by their nanoscale features.The LCA was carried out using the software SimaPro, and the Ecoinvent Life Cycle Inventory (LCI) database supplemented with available literature and patent information. Our results indicate that while QDPV modules have shorter Energy PayBack Time (EPBT), lower Global Warming Potential (GWP), SO_x and NO_x emissions than other types of PV modules, they have higher heavy metal emissions, underscoring the need for investigation of emerging technologies, especially nano-based ones, from a life cycle perspective. QDPV modules are better in all impact categories assessed than carbon-based energy sources but they have longer EPBT than wind and hydropower and higher GWP.     

Ash deposition impact on the energy performance of photovoltaic generators

A little known side effect of the atmospheric air pollution is the degradation of photovoltaic (PV) cells’ performance due to the deposition of solid particles varying in composition, size and origin. In this context, an experimental-based investigation is conducted in order to compare the energy performance of two identical pairs of PV-panels; the first being clean and the second being artificially polluted with ash, i.e. a by-product of incomplete hydrocarbons’ combustion mainly originating from thermal power stations and vehicular exhausts. A series of systematic measurements of current intensity, voltage output and solar radiation are executed simultaneously for the clean and the polluted PV-panel, so that the effect of several mass depositions on the PVs’ power output, energy yield and conversion efficiency may be determined. According to the results, a considerable deterioration of the PV-panels’ performance is obtained, i.e. almost 30% energy reduction per hour or 1.5% efficiency decrease (in absolute terms) for ash accumulation on the panels’ surface reaching up to 0.4 mg/cm².     

基于STIRPAT模型的能源消费碳足迹变化及影响因素——以江苏省苏锡常地区为例

定量研究经济社会发展对地区能源消费碳足迹的影响对区域实现低碳发展具有重要意义。论文计算了江苏省苏锡常地区1991-2008年能源消费碳足迹,采用岭回归函数对STIRPAT模型进行了拟合,采用脱钩指数分析了经济发展与能源消费碳足迹之间的关系。结果表明:①1991-2008年能源消费碳足迹平均增长速度为15.30%,能源消费碳足迹分配率以煤炭为主,石油所占比例呈波动下降趋势,天然气所占比例上升较快,能源消费碳足迹产值总体呈波动下降趋势;②经济增长是能源消费碳足迹的主要影响因素,两者关系模型拟合未出现环境库兹涅茨曲线;③经济增长与能源消费碳足迹之间处于相对脱钩与复钩的波动状态,从另一侧面验证了目前两者之间不存在库兹涅茨曲线假说的结论。     

中国地区经济差距及其演化的产业变动因素

20世纪90年代以来中国地区经济差距扩大具有深刻的产业变动原因。以人均GDP为基本指标,通过对基尼系数进行产业分解和对泰尔指数进行地区分解,深刻分析了1990~2004年中国地区经济差距的动态变化、地区构成和产业构成,揭示了中国地区经济差距及其演变的产业结构变动与产业地区集中因素。结果表明,1990年以来中国地区经济差距的决定性因素是第二产业发展水平的地区差距,而非农产业向东部沿海地区的集中又是推动中国地区经济差距扩大的主导性因素。20世纪90年代以来,随着以制造业为主的非农产业向东部沿海地区集中,中西部地区逐渐沦落为以农业与采掘业为主的外围区域,中国的地区经济差距也由此持续扩大。基于此,认为缩小地区差距的关键是推进中西部地区制造业发展,缓解非农产业地区分布的不平衡状况。     

空调系统冷冻水循环水泵变频运行的变温差控制

在分析空调系统变流量运行调节的基础上,提出了变温差控制并给出了控制方案。变温差控制过程不仅具有负反馈,而且具有正反馈,能较好的适应空调负荷的变化。比较分析了变温差控制、定温差控制、定压差控制的节能性,变温差控制的节能潜力最大,是一种最佳控制方式。     

Effect of platinum on the photocatalytic degradation of chlorinated organic compound

TiO2 nanoparticles, doped with di erent Pt contents, were prepared by a modified photodeposition method using Degussa P-25 TiO2, H2PtCl6 6H2O and methanol as the solvents. The physicochemical properties of Pt/TiO2 were investigated by the nitrogen adsorption and desorption isotherm measurement technique, X-ray di raction analysis and photoluminescence spectra, respectively. Reaction rates from photocatalytic removal of dichloromethane over Degussa P-25 TiO2 and Pt/TiO2 were evaluated. The average diameter and BET surface area of the TiO2 catalyst particles were 300 nm and 50 m2/g, respectively. The degradation e ciency was 99.0%, 82.7%, 55.2%, and 57.9% with TiO2 at inlet concentrations of 50, 100, 200, and 300 ppm, respectively. And the degradation e ciency was 99.3%, 79.7%, 76.5%, and 73.4% with a 0.005 wt.% Pt/TiO2 at inlet concentrations of 50, 100, 200, and 300 ppm, respectively. In addition, we found that the photoluminescence emission peak intensities decreased with increases in the doping amount of Pt, which indicates that the irradiative recombination was weakened. Furthermore, the results showed that the UV/0.005 wt.% Pt/TiO2 process was capable of e ciently decomposing gaseous DCM in air.     

动力与热力抬升对烟气抬升高度的影响分析

通过模式选择和计算,得出烟气抬升高度的增加与动能和热能的关系,表明当烟囱出口处风速分别为3 m/s、2 m/s和1 m/s时欲增加同样大小的烟气抬升高度,需要的动能比热能要高,结论认为烟气的热力提升比动力提升的贡献大。