国家重点生态功能区旅游资源开发的碳汇减损效应--国家级风景名胜区和5A级景区建设的准自然实验

国家重点生态功能区是保障生态文明战略有效推进的关键区域,“双碳”目标下考察旅游资源开发对国家重点生态功能区碳汇影响效应,有利于拓展旅游资源开发的环境外部性研究视野,并促进资源富集型欠发达地区旅游资源可持续利用。文章依托多源遥感影像构建733个国家重点生态功能区县域单元研究数据集,利用空间多期双重差分模型,以国家级风景名胜区和5A级景区建设为准自然实验,在县区精细尺度揭示旅游资源开发对碳汇影响及空间溢出效应。结果表明:1)国家重点生态功能区碳汇呈现微弱上升态势,但空间分异明显;2)旅游资源开发造成国家重点生态功能区碳汇减损,具有显著环境负外部性;3)旅游资源开发碳汇减损效应主要出现于中部、西部国家重点生态功能区,但在生态文明战略和国家重点生态功能区转移支付制度实施后得到缓解;4)旅游资源开发对碳汇的不利影响存在空间溢出性,“以邻为壑”特征明显。基于前述分析,文章进一步提出,理论上应探索将碳汇影响纳入旅游可持续发展评估研究框架;政策上推动旅游资源可持续开发利用,完善国家重点生态功能区旅游资源开发碳汇补偿制度,促进配套设施和关联产业科学布局和生态建设。

考虑网损的电力系统节点边际碳势理论研究与建模

用于电力系统碳排放计算的宏观核算法和碳流分析法未考虑网损、阻塞因素对电网边际碳排放的影响。为实现电网碳排放指标的精细化分析,建立考虑网损的电力系统节点边际碳势分析模型。考虑火电机组煤耗特性建立了机组的边际碳势模型;基于交流潮流模型,建立电网网损灵敏度模型;进而提出电力系统节点边际碳势的计算方法,并考虑网络阻塞因素进一步改进了该方法。采用IEEE 14节点系统和某500 kV实际系统算例验证了所建模型的合理性和适用性,分别分析了低碳和非低碳调度模式下节点碳势的变化规律;发现考虑网损后节点的正、负向边际碳势存在一定差异;网损因素也使得电网各节点边际碳势各异,考虑网损的模型可提供更为准确的节点边际碳势信息,可用于开展较为精准的实时碳排放分析。

电弧喷涂不锈钢工艺对涂层组织及碳烧损量的影响

研究了电弧喷涂工艺参数对3Cr13和1Cr18Ni9Ti不锈钢涂层组织结构和碳烧损量的影响．利用扫描电镜和X射线衍射方法分析了涂层的组织，用气体容量法测定了涂层的碳烧损量．讨论了电弧喷涂工艺因素影响的机理．

武钢高炉直接还原度及碳熔损率的计算与分析

对武钢7座高炉的直接还原度、碳熔损量、焦炭起始反应温度进行了研究,结果表明：武钢高炉直接还原度偏高且波动范围宽,为了降低焦比,需要发展间接还原;高炉碳熔损量在20%-25%之间,为了能够更加准确地指导高炉生产,需要进行恒定反应性的焦炭热性能实验;随着直接还原度降低,高炉煤气利用率呈线性升高,焦比呈线性降低;焦炭的起始反应温度受配煤比、工艺条件、炉型等因素的影响,其中工艺条件的影响最大。

回转窑碳质烧损分析

通过对Ф2 .2m× 45m回转窑碳质烧损计算 ,了解到回转窑的碳质烧损是较大的 ,分析回转窑煅烧碳质烧损的影响因素 ,探讨降低回转窑在煅烧中的碳质烧损的途径。

碳排放损益偏离的时空演化特征与影响因素分析

文章采用2010—2020年的市级面板数据,在对碳排放损益偏离定量测度的基础上,探究了其影响因素。研究表明:市域碳排放在时间上呈现出规模不断扩大的特征,在空间上呈现出由北向南递减、由东南向西北递增的特征,且存在显著的空间关联特征。碳排放的重心一直位于经济发展水平重心的北部,两者的错位距离呈现出倒“U”型的变化特征,存在明显的空间错位。碳排放损益偏离、市域单元的贡献度均呈现出明显的区域分异格局,由东到西不断递减。市场化水平、消费水平、金融发展水平、对外开放程度和绿色技术创新是碳排放损益偏离的重要影响因素,且存在显著的时空差异。最后,文章据此提出了针对性的碳减排对策。

硬质合金涂层界面η相对刀具使用性能的影响研究

通过冲击切削试验,研究了硬质合金刀具CVD涂层界面η相的形貌、厚度、分布形式对刀具使用性能的影响,分析了η相的产生原因并提出了控制方法。

UCAR炭砖在本钢5号高炉的应用分析

本钢5号高炉1990年大修时首次引进了UCAR小块炭砖,2001年停炉时对小块炭砖的破损情况进行了调查。通过对比分析发现,UCAR小块炭砖能有效延长高炉炉缸寿命。

Tribological and electric-arc behaviors of carbon/copper pair during sliding friction process with electric current applied

The tribological behaviors of carbon block sliding against copper ring with and without electric current applied were investigated by using an advanced multifunctional friction and wear tester, and the electric-arc behaviors were analyzed in detail. The results show that the normal load is one of the main controlling factors for generation of electric arc during friction process with electric current applied. The strength of electric arc is enhanced with the decrease of normal loads and the increase of electric currents. The unstable friction process and the fluctuated dynamic friction coefficients are strongly dependent upon the electric arc. The wear volumes and the wear mechanism of carbon brush were affected by the electric arc obviously. As no electric arc occurs, no clear discrepancy of the wear volumes of the carbon samples with and without electric current applied could be detected. While the wear mechanisms are mainly mechanical wear. However, under the condition of the electric arc appearance, the wear volume of carbon with electric current applied increases much more rapidly than that without electric current applied and also increases obviously with the increase of electric current strengths and the decrease of normal loads. The wear mechanisms of carbon block are mainly electric arc ablation accompanying with adhesive wear and material transferring.

Variation in litter decomposition-temperature relationships between coniferous and broadleaf forests in Huangshan Mountain, China

A study was conducted to identify the differences in the decompositions of leaf litter, lignin and carbohydrate between coniferous forest and broadleaf forest at 20℃ and 30℃ in Huangshan Mountain, Anhui Province, China. Results showed that at 20℃ mass loss of leaf litter driven by microbial decomposers was higher in broadleaf forest than that in coniferous forest, whereas the difference in mass loss of leaf litter was not significant at 30℃. The temperature increase did not affect the mass loss of leaf litter for coniferous forest treatment, but significantly reduced the decomposition rate for broadleaf forest treatment. The functional decomposers of microorganism in broadleaf forest produced a higher lignin decomposition rate at 20℃, compared to that in coniferous forest, but the difference in lignin decomposition was not found between two forest types at 30℃. Improved temperature increased the lignin decomposition for both broadleaf and coniferous forest. Additionally, the functional group of microorganism from broadleaf forest showed marginally higher carbohydrate loss than that from coniferous forest at both temperatures. Temperature increase reduced the carbohydrate decomposition for broadleaf forest, while only a little reduce was found for coniferous forest. Remarkable differences occurred in responses between most enzymes （Phenoloxidase, peroxidase, !5-glucosidase and endocellulase） and decomposition rate of leaf litter to forest type and temperature, although there exist strong relationships between measured enzyme activities and decomposition rate in most cases. The reason is that more than one enzyme contribute to the mass loss of leaf litter and organic chemical components. In conclusion, at a community scale the coniferous and broadleaf forests differed in their temperature-decomposition relationships.

Tribological properties of Ni-base alloy composite coating modified by both graphite and TiC particles

In order to reduce the friction coefficient of Ni-base alloy coating and further improve its wear resistance,Ni-base alloy composite coatings modified by both graphite and TiC particles were prepared by plasma spray technology on the surface of 45 carbon steel.The results show that friction coefficient of the composite coating is 47.45% lower than that of the Ni-base alloy coating,and the wear mass loss is reduced by 59.1%.Slip lines and severe adhesive plastic deformation are observed on the worn surface of the Ni-base alloy coating,indicating that the wear mechanisms of the Ni-base alloy coating are multi-plastic deformation wear and adhesive wear.A soft transferred layer abundant in graphite and ferric oxide is developed on the worn surface of the composite coating,which reduces the friction coefficient and wear loss in a great deal.The main wear mechanism of the composite coating is fatigue delamination of the transferred layer.

一种新的保护渣熔化速度的检测方法

利用碳烧损量是控制保护渣熔化速度的关键因素这一原理,用失重法检测了不同温度下保护渣的烧损量并尝试用于比较其熔化速度。研究表明,以碳烧损反映保护渣熔化速度的最佳温度是1 300℃,保护渣的熔化速度与渣中自由碳含量的烧损速度成正比。提出了以保护渣烧损曲线最后一个拐点对应的时间来表征其熔化速度的新方法。与传统检测方法相比,新方法能定量地区分不同保护渣的熔化速度的差别。

减少转炉提钒过程碳烧损

为了有效减少了转炉提钒过程的碳烧损量,在硅钼炉内进行氧化性炉渣与铁水在不同温度下的渣金反应实验,发现炉渣与铁水的反应速率随温度的升高而加快;温度越高铁红(Fe2O3)将钒氧化到极值的速度越快,但达到极值后钒会被还原回铁水中,且还原速度也随温度的升高而提高;温度越高钒渣中的钒被铁水中碳还原的量越大。根据实验结果对转炉提钒工艺进行了优化,吹炼温度为1340~1350℃时加入冷却剂,控制较低的终点温度,在钒氧化率不降低的情况下,碳烧损率从19.39%降到17.91%、碳烧损量从0.82%减少到0.76%,有效减少了转炉提钒过程的碳烧损。

Effect of electron beam irradiation on multi-walled carbon nanotubes

Multi-walled carbon nanotubes （MWCNTs） were irradiated with focused electron beams in a transmission electron microscope at room temperature. The results showed that carbon nanotubes had no obvious structural damages but only shell bending under 100 keV electron beam irradiation. However, when the electron energy increased to 200 keV, the nanotubes were damaged and amorphization, pits and gaps were detected. Furthermore, generating of carbon onions and welding between two MWCNTs occurred under 200 keV electron irradiation. It was easy to destroy the MWCNTs as the electron beams exceeded the displacement threshold energy that was calculated to be 83-110 keV. Conversely, the energy of electron beams below the threshold energy was not able to damage the tubes. The damage mechanism is sputtering and atom displacement.

资源禀赋、产业分工与碳排放损益偏离

文章借鉴Dagum基尼系数分解法测算了资源型与非资源型地区间碳排放损益偏离程度,并采用空间杜宾模型探讨了资源禀赋对碳排放损益偏离的影响,并以产业分工为突破口,探索资源禀赋影响碳排放损益偏离的传导途径。研究结果显示:(1)区域间碳排放损益偏离度总体呈波动式上升态势,碳排放损益偏离的相对"受损区"主要集中在山西、内蒙古、新疆等经济欠发达的资源型地区,而相对"受益区"主要集中在北京、上海、广东等经济较发达的非资源型地区;(2)资源禀赋会加剧碳排放损益偏离程度,且资源禀赋对碳排放损益偏离的"邻地效应"大于"本地效应";(3)产业分工是资源禀赋影响碳排放损益偏离的传导途径之一,但不同产业分工阶段对碳排放损益偏离的影响存在异质性。

Effects of extract from Ginkgo biloba on carbon tetrachloride-induced liver injury in rats

AIM： To study the effects of extract from Ginkgo biloba （EGb） containing 22% flavonoid and 5% terpenoid on chronic liver injury and liver fibrosis of rats induced by carbon tetrachloride （CCh）. METHODS： All rats were randomly divided into control group, CCl4-treated group, colchicine-treated group and EGb-protected group. Chronic liver injury was induced in experimental groups by subcutaneous injection of CCh and fed with chows premixed with 79.5% corn powder, 20% lard and 0.5% cholesterol （v/v）. EGb-protected group was treated with EGb （0.5 g/kg body weight per day） for 7 wk. At the end of wk 8, all the rats were killed. Liver function, liver fibrosis, oxidative stress and expression of transforming growth factor β1 （TGF-β1） a-smooth muscle actin （α-SMA） and type I collagens in liver were determined. In addition, pathology changes of liver tissue were observed under light microscope. RESULTS： The levels of alanine aminotransferase （ALT）, aspartate aminotransferase （AST） and albumin （AIb） in EGb-protected group were notably improved as compared with the CCL4-treated group （P 〈 0.01）. The contents of serum hyaluronic acid （HA）, type III procollagen （PCⅢ）, type IV collagen （CIV） and the expression of hepatic tissue TGF-β1, α-SMA and type I collagen in EGb-protected group were significantly lower than those in CCL4-treated groups （P 〈 0.05, P 〈 0.01）. The degrees of liver fibrosis in EGb-protected groups were lower than those in CCL4-treated groups （6.58 ±1.25 vs 9.52 ± 2.06, P 〈 0.05）. Compared to the CCL4-treated group, the levels of plasma glutathoine peroxidase （Se-GSH-Px）, superoxide dismutase （SOD） and malondialdehyde （MDA） were strikingly improved also in EGb-protected group （P 〈 0.05, P 〈 0.01）. CONCLUSION： EGb resists oxidative stress and thereby reduces chronic liver injury and liver fibrosis in rats with liver injury induced by CCl4.

PROTECTION OF CARBON MONOXIDE INHALATION ON LIPOPOLY-SACCHARIDE-INDUCED MULTIPLE ORGAN INJURY IN RATS

Objective To observe the protection of carbon monoxide （CO） inhalation on lipopolysaccharide （LPS）-induced rat multiple organ injury. Methods Sprague-Dawley rats with multiple organ injury induced by 5 mg/kg LPS intravenous injection were exposed to room air or 2.5 × 10 ^-4 （V/V） CO for 3 hours. The lung and intestine tissues of rats were harvested to measure the expression of heme oxygenase-1 （ HO-1 ） with reverse transcription-polymerase chain reaction, the levels of pulmonary tumor necrosis factor-or （ TNF-α）, interleukin-6 （ IL-6）, and intestinal platelet activator factor （ PAF）, intercellular adhesion molecule-1 （ICAM-1） with enzyme-linked immunosorbent assay, the content of maleic dialdehyde （MDA） and the activity of myeloperoxidase （MPO） with chemical method, the cell apoptosis rate with flow cytometry, and the pathological changes with light microscope. Results CO inhalation obviously up-regulated the expression of HO-1 in lung （5.43 ± 0. 92） and intestine （6. 29 ± 1.56） in LPS ＋ CO group compared with （ 3.08 ± 0. 82） and （ 3.97 ± 1.16 ） in LPS group （ both P 〈 0. 05 ）. The levels of TNF-ot, IL-6 in lung and PAF, ICAM-1 in intestine ofLPS ＋ CO group were 0. 91 ±0. 25,0. 64 ±0.05, 1. 19 ± 0. 52, and 1.83 ±0. 35 pg/mg, respectively, significantly lower than the corresponding values in LPS group （ 1.48 ± 0. 23, 1.16 ± 0. 26, 1.84 ± 0. 73, and 3.48 ± 0. 36 pg/mg, all P 〈 0. 05 ）. The levels of MDA, MPO, and cell apoptosis rate in lung and intestine of LPS ＋ CO group were 1.02 ± 0. 23 nmol/mg, 1.74 ± 0. 17 nmol/mg, 7.18 ± 1.62 U/mg, 6. 30 ±0. 97 U/mg, 1.60% ±0. 34%, and 30. 56% ±6. 33%, respectively, significantly lower than the corresponding values in LPS group （ 1.27 ± 0. 33 nmol/mg, 2. 75 ± 0. 39 nmol/mg, 8. 16 ± 1.49 U/mg, 7. 72 ± 1.07 U/mg, 3.18% ±0. 51%, and 41.52% -＋3.36%, all P 〈0.05）. In addition, injury of lung and intestine induced by LPS was attenuated at presence of CO inhalation. Conclusion CO inhalation protects rat lung and intestine from LPS-induced injury via anti-oxidantion, anti-inflammation, anti-apoptosis, and up-regulation of HO-1 expression.

Fabrication of Co-Ni-P film with excellent wear and corrosion resistance by electroplating with supercritical CO_2 emulsion

To avoid the defects caused by the hydrogen evolution and improve the corrosion and wear properties of the electroplated films in the traditional aqueous bath electrodeposition,a supercritical carbon dioxide(Sc-CO2)emulsion was proposed to electrodeposite ternary nanocrystalline Co-Ni-P alloy films.Microstructure,corrosive and tribological properties of the Co-Ni-P films were investigated and compared with the ones electroplated by conventional method.The results show that the Co-Ni-P films produced with Sc-CO2assisted electrodeposition exhibit a more compact microstructure.The preferred orientation plane of hcp(110)for the Co-Ni-P films produced in conventional aqueous bath is changed to be hcp(100)for the one prepared in emulsified Sc-CO2bath.The microhardness,corrosion resistance and tribological properties of the Co-Ni-P films are substantially improved with the assistance of Sc-CO2in the electrodeposition bath.

Hepatic injury induced by carbon dioxide pneumoperitoneum in experimental rats

AIM： To observe the hepatic injury induced by carbon dioxide pneumoperitoneum in rats and to explore its potential mechanism.METHODS： Thirty healthy male SD rats were randomly divided into control group （n = 10）, 0 h experimental group （n = 10） and 1 h experimental group （n = 10） after sham operation with carbon dioxide pneumoperitoneum. Histological changes in liver tissue were observed with hematoxylineosin staining. Liver function was assayed with an automatic biochemical analyzer. Concentration of malonyldialdehyde （MDA） and activity of superoxide dismutase （SOD） were assayed by colorimetry. Activity of adenine nucleotide translocator in liver tissue was detected with the atractyloside-inhibitor stop technique. Expression of hypoxia inducible factor-1 （HIF-1） mRNA in liver tissue was detected with in situ hybridization.RESULTS： Carbon dioxide 60 min could induce liver pneumoperitoneum for injury in rats. Alanine aminotransferase and aspartate aminotransferase were 95.7 ± 7.8 U/L and 86.8 ± 6.9 U/L in 0 h experimental group, and 101.4 ± 9.3 U/L and 106.6 ±8.7 U/L in 1 h experimental group. However, no significant difference was found in total billirubin, albumin, and pre-albumin in the three groups. In 0 h experimental group, the concentration of MDA was 9.83 ±2.53 μmol/g in liver homogenate and 7.64 ± 2.19 μmol/g in serum respectively, the activity of SOD was 67.58±9.75 nu/mg in liver and 64.47 ± 10.23 nu/mg in serum respectively. In 1 h experimental group, the concentration of MDA was 16.57±3.45 μmol/g in liver tissue and 12.49 ±4.21 μmol/g in serum respectively, the activity of SOD was 54.29 ±7.96 nu/mg in liver tissue and 56.31 ±9.85 nu/mg in serum respectively. The activity of ANT in liver tissue was 9.52 ± 1.56 in control group, 6.37± 1.33 in 0 h experimental group and 7.2 8±1.45 （10^-9 mol/min per gram protein） in 1 h experimental group, respectively. The expression of HIF-1 mRNA in liver tissue was not detected in control group, and its optical density difference value was 6.14±1.03 in 0 h experimental group and 9.51 ± 1.74 in 1 h experimental group, respectively. CONCLUSION： Carbon dioxide pneumoperitoneum during the sham operation can induce hepatic injury in rats. The probable mechanisms of liver injury include anoxia, ischemia reperfusion and oxidative stress. Liver injury should be avoided during clinical laparoscopic operation with carbon dioxide pneumoperitoneum.

Two clinically relevant pressures of carbon dioxide pneumoperitoneum cause hepatic injury in a rabbit model

AIM:To observe the hepatic injury induced by carbon dioxide pneumoperitoneum(CDP) in rabbits,compare the eects olow-and high-pressure pneumoperitoneum,and to determine the degree o hepatic injury induced by these two clinically relevant CDP pressures.METHODS:Thirty healthy male New Zealand rabbits weighing 3.0 to 3.5 kg were randomly divided into three groups(n = 10 for each group) and subjected to the ollowing to CDP pressures:no gas control,10 mmHg,or 15 mmHg.Histological changes in liver tissues were observed with hematoxylin and eosin staining and transmission electron microscopy.Liver unction was evaluated using an automatic biochemical analyzer.Adenine nucleotide translocator(ANT) activity in liver tissue was detected with the atractyloside-inhibitor stop technique.Bax and Bcl-2 expression levels were detected bywestern blotting.RESULTS:Liver Functions in the 10 mmHg and 15 mmHg experimental groups were significantly disturbed compared with the control group.After CDP,the levels or alanine transaminase and aspartate transaminase were 77.3 ± 14.5 IU/L and 60.1 ± 11.4 IU/L,respectively,in the 10 mmHg experimental group and 165.1 ± 19.4 IU/L and 103.8 ± 12.3 IU/L,respectively,in the 15 mmHg experimental group,which were all higher than those of the control group(p < 0.05).There was no difference in pre-albumin concentration between the 10 mmHg experimental group and the control group,but the prealbumin level of the 15 mmHg experimental group was significantly lower than that of the control group(p < 0.05).No significant differences were observed in the levels of total bilirubin or albumin among the three groups.After 30 and 60 min of CDP,pH was reduced(p < 0.05) and fa CO2 was elevated(p < 0.05) in the 10 mmHg group compared with controls,and these changes were more pronounced in the 15 mmHg group.Hematoxylin and eosin staining showed no significant change in liver morphology,except for mild hyperemia in the two experimental groups.Transmission electron microscopy showed mild mitochondrial swelling in hepatocytes of the 10 mmHg group,and this was more pronounced in the 15 mmHg group.No significant difference in ANT levels was found between the control and 10 mmHg groups.However,ANT concentration was significantly lower in the 15 mmHg group compared with the control group.The expression of hepatic Bax was significantly increased in the two experimental groups compared with the controls,but there were no differences in Bcl-2 levels among the three groups.Twelve hours after CDP induction,the expression of hepatic Bax was more significant in the 15 mmHg group than in the 10 mmHg group.CONCLUSION:A CDP pressure of 15 mmHg caused more substantial hepatic injury,such as increased levels of acidosis,mitochondrial damage,and apoptosis;therefore,10 mmHg CDP is preferable for laparoscopic operations.