中国国家资源环境安全问题初探

作为世界上最大的发展中国家 ,中国资源环境的现实基础表现出明显脆弱的特征。更严重的问题是 ,未来人口的增长和生活水平的提高对现已十分脆弱的国家资源环境安全基础产生着巨大的压力。若在此问题上出现认识和发展政策上的失误 ,便会产生巨大负面效应 ,严重影响中国国家现代化的进程。为此 ,建议 2 1世纪中国可持续发展战略的首要任务应是确保国家资源环境安全的稳定性。     

锅炉监控仪表的改进与实践

在原有"锅炉高低水位报警器"的基础上,研制出锅炉智能监控仪表.该仪表系统实现了自动操作、失误防护、报警及连锁保护等功能,对锅炉各类事故有积极的预防作用.     

Elevated CO2 stimulates net accumulations of carbon and nitrogen in land ecosystems: a meta-analysis

The capability of terrestrial ecosystems to sequester carbon (C) plays a critical role in regulating future climatic change yet depends on nitrogen (N) availability. To predict long-term ecosystem C storage, it is essential to examine whether soil N becomes progressively limiting as C and N are sequestered in long-lived plant biomass and soil organic matter. A critical parameter to indicate the long-term progressive N limitation (PNL) is net change in ecosystem N content in association with C accumulation in plant and soil pools under elevated CO2. We compiled data from 104 published papers that study C and N dynamics at ambient and elevated CO2. The compiled database contains C contents, N contents, and C:N ratio in various plant and soil pools, and root:shoot ratio. Averaged C and N pool sizes in plant and soil all significantly increase at elevated CO2 in comparison to those at ambient CO2, ranging from a 5% increase in shoot N content to a 32% increase in root C content. The C and N contents in litter pools are consistently higher in elevated than ambient CO2 among all the surveyed studies whereas C and N contents in the other pools increase in some studies and decrease in other studies. The high variability in CO2-induced changes in C and N pool sizes results from diverse responses of various C and N processes to elevated CO2. Averaged C:N ratios are higher by 3% in litter and soil pools and 11% in root and shoot pools at elevated relative to ambient CO2. Elevated CO2 slightly increases root:shoot ratio. The net N accumulation in plant and soil pools at least helps prevent complete down-regulation of, and likely supports, long-term CO2 stimulation of C sequestration. The concomitant C and N accumulations in response to rising atmospheric CO2 may reflect intrinsic nature of ecosystem development as revealed before by studies of succession over hundreds to millions of years.     

Anthropogenic nitrogen sources and exports in a village-scale catchment in Southeast China

An experimental village-scale catchment was selected for investigation of nitrogen (N) sources and exports. The mean N application rate over the catchment was 350.2 kg N ha⁻¹, but this rate varied spatially and temporally. The N leaching loss rate varied from 8.1 to 52.7 kg N ha⁻¹ under different land use regimes. The average N leaching loss rate was 13.4 kg N ha⁻¹ over the whole catchment, representing about 3.8% of the total N inputs. The N export rate through stormflows was 28.8 kg N ha⁻¹, about 8.2% of the total N inputs. Seasonal patterns showed that 95% of N exports through stormflows occurred during July to September in 2002. Overall, the maximum riverine N exports were 12.1% of total N inputs and 15.5% of the inorganic fertilizer N applied. Understanding N sources and exports in a village-scale catchment can provide a knowledge base for amelioration of diffuse agricultural pollution.     

Methods for the preparation of a biodesulfurization biocatalyst using Rhodococcus sp

Several methods to prepare a biodesulfurization (BDS) biocatalyst were investigated in this study using a strain of Rhodococcus sp. 1awq. This bacterium could selectively remove sulfur from dibenzothiophene (DBT) via the "4S" pathway. DBT, dimethylsulfoxide (DMSO), sodium sulphate and mixed sulfur sources were used to study their influence on cell density, desulfurization activity, desulfurization ability, and the cost of biocatalyst production. In contrast to that observed from bacteria cultured in DBT, only partial desulfurization activity of strain 1awq was induced by DBT after cultivation in a medium containing inorganic sulfur as the sole sulfur source. The biocatalyst, prepared from culture with mixed sulfur sources, was found to possess desulfurization activity. With DMSO as the sole sulfur source, the desulfurization activity was shown to be similar to that of bacteria incubated in medium with DBT as the sole sulfur source. The biocatalyst prepared by this method with the least cost could remove sulfur from hydrodesulfurization (HDS)-treated diesel oil efficiently, providing a total desulfurization percent of 78% and suggesting its cost-effective advantage.     

示踪技术用于气体泄漏扩散模拟的多元线性回归分析

采用江苏工业学院油气储运安全综合实验模型平台,利用示踪技术(以CO2为示踪剂),模拟了有害气体瞬时泄漏扩散的整个过程.并结合多元线性回归分析的基本方法,定量分析了气体泄漏扩散过程,建立了多元线性回归模型,初步确定了泄漏气体浓度与相关物理量的变化关系,在此基础上得到了2个定量评价指标:确定性系数R=0.991,相关系数r=0.995.研究表明,在实验室建立的试验模型能较好地反映现实情况,模型仿真度较高,数据拟合效果较好.研究可为评价模型的相似性提供理论参考,对有害气体泄漏扩散事故应急救援、实施有效的现场控制,具有一定的科学参考价值.     

袋式除尘技术在我国燃煤电厂的推广应用

回顾了袋式除尘技术在我国燃煤电厂的推广应用历程,论述了我国燃煤锅炉烟气的特殊工况条件和袋式除尘器对治理电厂锅炉烟气的综合优势,总结了我国燃煤电厂对推广应用袋式除尘作出的贡献。展望在下一阶段实施新修订的《火电厂大气污染物排放标准》的过程中,袋式除尘器必将对电厂节能排减发挥更大作用。     

氯化亚锡还原光度法测总磷的改进

通过大量试验,对氯化亚锡还原光度法测定总磷过程中如何延长氯化亚锡、磷酸二氢钾试剂的使用保存期、提高显色的稳定度、降低空白值,提出了切实可行的改进方法。     

"中国地震动参数区划图编制"荣获2003年度国家科技进步二等奖

2004年2月20日,中共中央、国务院在北京隆重举行国家科学技术奖励大会。党和国家领导人胡绵涛等出席大会并为获奖代表颁奖。温家宝总理代表党中央、国务院在大会上讲话。     

武钢签订安全生产目标责任状制度概述

概略地分析了武钢安全生产目标责任状制度的内容、作用和目的 ,以及实施和管理该责任制的一些主要做法、措施。通过实施签订安全生产目标责任状制度 ,促使各级领导、各部门落实安全生产责任制 ,取得了成效 ,确保了安全生产