中国碳排放及影响因素的市域尺度分析

评估区域碳排放及其与社会经济状况的关系对于制定碳减排措施至关重要.以中国339个地级及以上城市(不含新疆部分城市和港澳台地区)为研究对象,探究了非化石能源占比、土地开发度、常住人口城镇化率、第二产业占比、人均GDP和人均建设用地面积对人均CO₂排放量的影响.通过构建模拟人均CO₂排放量的贝叶斯信念网络,识别各因素对人均CO₂排放量的全局影响;采用多尺度地理加权回归模型,分析各因素对人均CO₂排放量的局部影响.结果表明：(1)2020年,中国地级及以上城市人均CO₂排放量呈现出由南向北递增,东部沿海向内陆递减的格局.(2)从全局来看,人均CO₂排放量对各因素的敏感性从高到低依次为：人均建设用地面积>人均GDP>常住人口城镇化率>土地开发度>第二产业占比>非化石能源占比.(3)从局部来看,各因素与人均CO₂排放量的空间关系方向与全局关系一致,关系强度上存在空间异质性.(4)清洁能源、脱碳技术、土地节约集约利用...     

Performance of an aerodynamic particle separator

This compact, high-flow device aerodynamically separates small particles from a gas stream by a series of annular truncated airfoils. The operating concept, design and performance of this novel particle separator are described. Tests results using corn starch and post-cyclone coal fly ash are presented. Particle collection efficiencies of 90% for corn starch and 70% for coal fly ash were measured at inlet velocities of 80 ft s⁻¹ (2700 cfm) and (6 inches) water pressure drop with particle loading up to 4 gr ft⁻³ in air at standard conditions. Results from computer modeling using FLUENT are presented and compared to the tests. The aerodynamic particle separator is an attractive alternative to a cyclone collector.     

湖北省暴雨灾害及防御对策初探

本文对湖北省暴雨灾害的时空分布、经济损失连锁反映特征作了分析,提出抗灾教灾和防御对策的应急措施和长远规划。     

苜蓿对土壤生态环境的影响

本文论述了黑龙港低平原缺水盐渍地区苜蓿对土壤结构、土壤水分、养分和盐分的影响。苜蓿对改善土壤生态环境,实现草地生态系统良性循环,起着重要作用。     

控制人口 保护资源 为子孙留下蓝天碧水绿地

建国40多年来,淄博市的国民经济和社会事业迅速发展,已经成为一个以重工业为主体的重要工业城市。同时,随着经济规模的迅速扩大,人口、资源与环境三大问题越来越突出。面对这样的市情,淄博市采取各种措施,突出重点,集中力量主攻薄弱环节,严格控制人口增长,保护资源,综合整治污染,取得了很大成效,初步走上了经济和社会事业与人口、资源、环境协调发展的轨道。     

Adding infection to injury: synergistic effects of predation and parasitism on amphibian malformations

We explored the importance of interactions between parasite infection and predation in driving an emerging phenomenon of conservation importance: amphibian limb malformations. We suggest that injury resulting from intraspecific predation in combination with trematode infection contributes to the frequency and severity of malformations in salamanders. By integrating field surveys and experiments, we evaluated the individual and combined effects of conspecific attack and parasite (Ribeiroia ondatrae) infection on limb development of long-toed salamanders (Ambystoma macrodactylum). In the absence of Ribeiroia, abnormalities involved missing digits, feet, or limbs and were similar to those produced by cannibalistic attack in experimental trials. At field sites that supported Ribeiroia, malformations were dominated by extra limbs and digits. Correspondingly, laboratory exposure of larval salamanders to Ribeiroia cercariae over a 30-day period induced high frequencies of malformations, including extra digits, extra limbs, cutaneous fusion, and micromelia. However, salamander limbs exposed to both injury and infection exhibited 3-5 times more abnormalities than those exposed to either factor alone. Infection also caused significant delays in limb regeneration and time-to-metamorphosis. Taken together, these results help to explain malformation patterns observed in natural salamander populations while emphasizing the importance of interactions between parasitism and predation in driving disease.     

Ionic liquid-containing semipermeable membrane devices for monitoring the polycyclic aromatic hydrocarbons in water

Ionic liquid-containing semipermeable membrane devices (IL-SPMDs) were developed to monitor the polycyclic aromatic hydrocarbons in water. Uptake kinetics of naphthalene, 1-methylnaphthalene, phenanthrene, pyrene, chrysene by layflat low-density polyethylene tubing (15 cm x 2 cm) filled with 0.5 ml 1-butyl-3-methylimidazolium hexafluorophosphate ionic liquid were studied in a laboratory continuous-flow system for the duration of 16 days. The device concentration factors were in the range of 830-7800 for the studied PAHs. The kinetic parameters of IL/water partition coefficients, analytes uptake rate constants and sampling rates were estimated using mathematical models. These parameters were used in the field experiment to estimate the concentrations of the PAHs in Lanzhou section of Yellow River in China, with the result in comparison with that obtained by triolein-SPMD.     

Effect of nonylphenol on steroidogenesis of rat Leydig cells

Nonylphenol is the primary final biodegradation product of nonylphenol polyethoxylate (NPE), a non-ionic surfactant that is frequently incorporated into pesticide and detergent formulation. Recent researchers have hypothesized that environmental/ occupational exposure to nonylphenol poses adverse effects on reproductive system of humans and wildlife species. During our study, in vivo and in vitro experiments were performed to examine the effect of nonylphenol on testosterone biosynthesis of rat Leydig cells. In experiment in vivo, serum testosterone (T) as well as luteinizing hormone (LH) levels were detected after animals had been treated with different doses (0 mg/kg/day, 125 mg/kg/day, and 250 mg/kg/day) of nonylphenol for 50 days by gavage, and the final result revealed that testosterone level dramatically declined at the dose of 250 mg/kg/day, while LH level ascended at the dose of 125 mg/kg/day and 250 mg/kg/day. In experiment in vitro, primary cultured Leydig cells were exposed to nonylphenol for 48 h, including low concentrations (0 mg/L, 0.0011 mg/L, 0.0033 mg/L, 0.0055 mg/L, 0.011 mg/L, 0.022 mg/L) and higher concentrations (0.11 mg/L, 0.55 mg/L, 1.1 mg/L, 1.65 mg/L, 2.2 mg/L, 2.75 mg/L, 3.3 mg/L, 5.5 mg/L). Increase of testosterone levels was observed at low concentrations of nonylphenol while reduction was detected at higher concentrations.