探讨氮中氧、空气中异丁烷气体标准样品的研制

本文叙述气体报警仪标定和检测使用的氮中氧、空气中异丁烷气体标准样品的制备,以气相色谱法对其均匀性和稳定性进行考核,确保其数据准确可靠。

重量法制备氮中微量氧气体标准物质

介绍重量法制备氮中微量氧气体标准物质的实验方法和结果。考察了环境空气对微量氧配制过程中引入误差的影响,对称量法制备气体标准物质不确定度进行了评定并对不确定度进行了验证,验证结果吻合在1%之内;氧含量在0～10μmol/mol范围内重量法制备的气体标准物质的不确定度小于1%,并且取得了国际的等效性。

氮中微量氧气体标准物质分析方法和定值方法的研究(下)

介绍了氮中微量氧标准气体的分析方法，给出了分析条件和方法的精密度，并对该标准气体配制的均匀性、稳定性的实验结果进行了分析与考察，对该气体标准物质的性能进行了评价。氧含量在（2—10）μmoL／mol浓度范围气体标准物质定值不确定度〈±2％；氧含量在（20～100）μmol／mol浓度范围气体标准物质定值不确定度〈±1％，取得了国际的等效性。

氮中微量氧气体标准物质分析方法和定值方法的研究(上)

介绍了氮中微量氧标准气体的分析方法，给出了分析条件和方法的精密度，并对该标准气体配制的均匀性、稳定性的实验结果进行了分析与考察，对该气体标准物质的性能进行了评价。氧含量在（2～10）μmol／mol浓度范围气体标准物质定值不确定度〈±2％；氧含量在（20～100）μmol／mol浓度范围气体标准物质定值不确定度〈±1％，取得了国际的等效性。

高纯氮中微量氧分析的不确定度和氧气体标准物质在有效期内变化不确定度计算方法的讨论

介绍了氮中微量氧标准气体在研究过程中稀释气体高纯氮中氧分析不确定度的评价依据,给出了评价过程和结果。讨论了氧气体标准物质在有效期内变化不确定度的计算方法,对氧气体标准物质定值不确定度进行了评价。

钢中氧氮标准样品研制的思考

上海钢铁研究所是最早从事钢中氧氮标准样品工作的单位之一,就我国钢中氧氮标准样品的研制、体系等有关工作谈几点看法,以供参考。

一次性综合检测钢铁中O、N、H三种元素含量的惰性气体熔融测定方法不确定度评定

本文主要对一次性综合检测钢铁中O、N、H三种元素含量的惰性气体熔融测定方法进行不确定度评定,分析该方法在检测过程中各因素对测定结果的影响,重点介绍了该测定方法原理、评定步骤、评定报告、主要影响因素及措施等内容。

Promotional effects of Zr on K^+-poisoning resistance of CeTiO_x catalyst for selective catalytic reductionof NO_x with NH_3

CeTiOx and CeZrTiOx catalysts were prepared by a coprecipitation method and used for selective catalytic reduction of NOx by NH3 （NH3‐SCR）. Various amounts of KNO3 were impregnated on the catalyst surface to investigate the effects of Zr addition on the K＋‐poisoning resistance of the CeTiOx catalyst. The NH3‐SCR performance of the catalysts showed that the NOx removal activity of the Zr‐modified catalyst after poisoning was better than that of the CeTiOx catalyst. Brunau‐er‐Emmett‐Teller data indicated that the Zr‐containing catalyst had a larger specific surface area and pore volume both before and after K＋poisoning. X‐ray diffraction, Raman spectroscopy, and transmission electron microscopy showed that Zr doping inhibited anatase TiO2 crystal grain growth, i.e., the molten salt flux effect caused by the loaded KNO3 was inhibited. The Ce 3d X‐ray photoelectron spectra showed that the Ce3＋/Ce4＋ratio of CeZrTiOx decreased more slowly than that of CeTiOx with increasing K＋loading, indicating that Zr addition preserved more crystal defects and oxygen vacancies; this improved the catalytic performance. The acidity was a key factor in the NH3‐SCR performance; the temperature‐programmed desorption of NH3 results showed that Zr doping inhibited the decrease in the surface acidity. The results suggest that Zr improved the K＋‐poisoning resistance of the CeTiOx catalyst.

Effects of Reclamation on Soil Carbon and Nitrogen in Coastal Wetlands of Liaohe River Delta,China

To evaluate the influence of wetland reclamation on vertical distribution of carbon and nitrogen in coastal wetland soils, we measured the soil organic carbon(SOC), soil total nitrogen(STN) and selected soil properties at five sampling plots(reed marsh, paddy field, corn field, forest land and oil-polluted wetland) in the Liaohe River estuary in September 2013. The results showed that reclamation significantly changed the contents of SOC and STN in the Liaohe River estuary(P < 0.001). The SOC concentrations were in the order: oil-polluted wetland > corn field > paddy field > forest land > reed marsh, with mean values of 52.17, 13.14, 11.46, 6.44 and 6.16 g/kg, respectively. STN followed a similar order as SOC, with mean values of 1351.14, 741.04, 632.32, 496.17 and 390.90 mg/kg, respectively. Interaction of reclamation types and soil depth had significant effects on SOC and STN, while soil depth had significant effects on SOC, but not on STN. The contents of SOC and STN were negatively correlated with pH and redox potential(Eh) in reed marsh and corn field, while the SOC and STN in paddy field had positive correlations with electrical conductivity(EC). Dissolved organic carbon(DOC), ammonium nitrogen(NH_4^+-N) and nitrate nitrogen(NO_3~–-N) were also significantly changed by human activities. NH_4^+-N and NO_3~–-N increased to different degrees, and forest land had the highest NO_3~–-N concentration and lowest DOC concentration, which could have been caused by differences in soil aeration and fertilization. Overall, the results indicate that reed harvest increased soil carbon and nitrogen release in the Liaohe River Estuary, while oil pollution significantly increased the SOC and STN; however, these cannot be used as indicators of soil fertility and quality because of the serious oil pollution.

Application of Stable Isotope Techniques in Studies of Carbon and Nitrogen Biogeochemical Cycles of Ecosystem

Stable isotope techniques have been proved useful as tools for studying the carbon (C) and nitrogen (N) biogeochemical cycles of ecosystem. This paper firstly introduced the basic principles and the distribution characteristics of stable isotope, then reviewed the recent advances and applications of stable isotope in the C and N biogeochemical cycles of ecosystem. By applying the 13 C natural abundance technique, ecologists are able to understand the photosynthetic path and CO 2 fixation of plants, the CO 2 exchange and C balance status of ecosystem, the composition, distribution and turnover of soil organic C and the sources of organic matter in food webs, while by using the 13 C labeled technique, the effects of elevated CO 2 on the C processes of ecosystem and the sources and fate of organic matter in ecosystem can be revealed in detail. Differently, by applying the 15 N natural abundance technique, ecologists are able to analyze the biological N 2 -fixation, the N sources of ecosystem, the N transformation processes of ecosystem and the N trophic status in food webs, while by using the 15 N labeled technique, the sources, transformation and fate of N in ecosystem and the effects of N input on the ecosystem can be investigated in depth. The applications of both C and N isotope natural abundance and labeled techniques, combined with the elemental, other isotope ( 34 S) and molecular biomarker information, will be more propitious to the investigation of C and N cycle mechanisms. Finally, this paper concluded the problems existed in current researches, and put forward the perspective of stable isotope techniques in the studies on C and N biogeochemical cycles of ecosystem in the future.

冶金竖窑石灰质量的控制途径

对影响竖窑石灰质量的因素进行分析,介绍了严格原燃料的质量控制、稳定煅烧制度和加强各项管理工作等提高石灰质量的有效途径。

Effects of precipitation variation on severe acid rain in southern China

Acid rain has been recognized as a serious environmental problem in China since the 1980s, but little is known about the effects of the climatic change in regional precipitation on the temporal and spatial variability of severe acid rain. We present the effects of the regional precipitation trend change on the area and intensity of severe acid rain in southern China, and the spatio-temporal distribution characteristics of SO2 and NO2 concentrations are analyzed on the basis of SO2 and NO2 column concentration data. The results are as follows. （1） The emission levels of SO2 and NO2 have reached or passed the precipitation scavenging capacity in parts of southern China owing to the emission totals of SOz and NO2 increasing from 1993 to 2004. （2） Notable changes in the proportion of cities subject to severe acid rain occurred mainly in the south of the middle-lower reaches of the Yangtze River during 1993-2004. With an abrupt change in 1999, the severe acid rain regions were mainly located in central and western China during 1993-1999 and moved obviously eastward to the south of the lower-middle reaches of the Yangtze River with the proportion of cities subject to severe acid rain increasing significantly from 2000 to 2004. （3） The spatial distribution and variation in the seasonal precipitation change rate of more than 10 mm/10a are similar to those of severe acid rain in southern China. An abrupt change in 1999 is seen for winter and summer precipitation, the same as for the proportion of cities subject to severe acid rain in southern China. The significant increase in summer storm precipitation from 1991 to 1999 mitigated the annual precipitation acidity in the south of the Yangtze River and reduced the area of severe acid rainfall. On the other hand, the decrease in storm rainfall in summer expanded the area of severe acid rainfall in the south of the Yangtze River in 2000-2006. Therefore, the change in seasonal precipitation is an important factor in the severe acid rain regions moving eastward and expanding in southern China.

Simultaneous formation of a C/N-TiO_2 hollow photocatalyst with efficient photocatalytic performance and recyclability

Herein,we report a unique approach towards the preparation of C-modified and N-doped TiO2 hollow spheres(C/N-TiO2).TEM,SEM,and XPS analyses were used to confirm that the carbon and nitrogen co-decorated TiO2 photocatalyst was formed.Carbon-decoration improves the visible-light absorption and speeds up the separation of the photo-generated electron-hole pairs.C/N-TiO2 not only narrows the band gap of TiO2,but also exhibits excellent photocatalytic activity for the degradation of tetracycline and tetracycline hydrochloride.In addition,the C/N-TiO2 photocatalyst shows excellent recyclability for water decontamination,making it a promising candidate to purify aquatic contaminants.

Progress and prospects of photocatalytic conversion of low-concentration NOx

NOx can cause severe environmental problems such as acid rain and photochemical smog,endangering human health and the living environment.Among them,NO pollution accounts for about 95%.NO can exist stably in the air for a long time when the concentration is lower than the ppm level.Therefore,the conversion of low concentration of NO has attracted more and more attention.However,traditional physical or chemical methods are difficult to deal with low concentration of NO,having high requirements on equipment and being not cost‐effective.Semiconductor photocatalytic technology can convert low concentration of NO into non‐toxic products and reduce its harm.This work briefly surveys the commonly used materials,modification methods,and mechanisms for semiconductor photocatalytic conversion of low concentration of NO.In addition,the challenges and prospects of ppb level of NO treatment are also discussed,aiming to promote the development of semiconductor photocatalytic conversion of NO.

Effects of Warm Needling at Zusanli(ST 36)on NO and IL-2 Levels in the Middle-Aged and Old People

42 middle-aged and old people at the age between 55-70 years were selected and given the warm needling at Zusanli (ST 36), and their IL-2 and NO contents of peripheral blood before and after acupuncture were determined. The results showed that IL-2 and NO contents increased significantly after the warm needling (P<0.01).

Endothelial Nitric Oxide Synthase Gene Polymorphisms Associated with Susceptibility to High Altitude Pulmonary Edema in Chinese Railway Construction Workers at Qinghai-Tibet over 4500 Meters above Sea Level

Objective To examine whether the polymorphisms of endothelial nitric oxide synthase (eNOS) gene are associated with the susceptibility to high altitude pulmonary edema (HAPE) in Chinese railway construction workers at Qinghai-Tibet where the altitude is over 4 500 m above sea level. Methods A case-control study was conducted including 149 HAPE patients in the construction workers and 160 healthy controls randomly recruited from their co-workers, matching the patients in ethnicity, age, sex, lifestyle, and working conditions. Three polymorphisms of eNOS gene, T-786C in promoter, 894G/T in exon 7, and 27bp variable number tandem repeat (VNTR) in intron 4, were genotyped using polymerase chain reaction (PCR) and confirmed with DNA sequencing. Results The frequencies of 894T allele and heterozygous G/T of the 894G/T variant were significantly higher in HAPE patients group than in the control group (P=0.0028 and P=0.0047, respectively). However, the frequencies of the T-786C in promoter and the 27bp VNTR in intron 4 were not significantly different between the two groups. Haplotypic analysis revealed that the frequencies of two haplotypes (H3,T-T-b, b indicates 5 repeats of 27 bp VNTR; H6, C-G-a, a indicates 4 repeats of 27 bp VNTR) were significantly higher in HAPE patients (both P<0.0001). On the contrary, the frequencies of H1 (T-G-b) and H2 (T-G-a) were lower in HAPE patients than in healthy controls (both P<0.001). Conclusions Two haplotypes (T-T-b and C-G-a) may be strongly associated with susceptibility to HAPE. Compared with the individual alleles of eNOS gene, the interaction of multiple genetic markers within a haplotype may be a major determinant for the susceptibility to HAPE.

氧气透过率仪校准方法探讨

本文介绍了用氮中氧气体标准物质校准氧气透过率仪的可行性，对校准过程中可能对校准结果不确定度有影响的㈨素进行了分析，并给出了校准不确定度的计算公式。

Application of Tunable Diode Laser Absorption Spectroscopy with Optical Hollow Fiber to Engine Exhaust Gas Measurement

In recent years, tighter regulation has been already enforced on harmful substances such as NOx, CO, and particles. Considering the above situation, it is important to monitor controlling factors of engine systems in order to improve efficiencies of their operations. As to car engines, an increasing concern in environmental issues such as air pollution, global warming and petroleum depletion has helped drive researches into various ways. Laser diagnostics has been applied to measure species concentration in the actual industrial fields. However there are several challenges to proceed in applying laser diagnostics to practical application. Especially stability of the measurement system is one of the most difficult issues. The purpose of this research is the development of a prompt measurement technique which can be applicable to various engine conditions. The Tunable Diode Laser Absorption Spectroscopy （TDLAS） using the hollow fiber has been developed to satisfy above requirements. By using a hollow fiber, misalignment of an optical axis and vulnerability of measurement environment such as vibration can be greatly reduced with sensitive and fast response features. It was demonstrated that this method can be applicable to measure gas compositions in engine exhaust with a range of millisecond response time. A sensitive method using tunable UV diode laser absorption spectroscopy was also discussed to detect NOx in exhausts.

Identification of novel cyclic nucleotide phosphodiesterase gene cDNAs in the brain of guinea pig

Objective Cyclic nucleotide phosphodiesterase（PDE）is a critical component of the nitric oxide（NO）signaling pathway and plays critical roles in cognition and learning,Parkinson’s disease,attention deficit hyperactivity disorder, psychosis and depression.The PDEs in the brain of guinea pig have not yet been reported.The present study aimed to detect the unknown Pde cDNAs in the brain of guinea pig.Methods Reverse transcription polymerase chain reaction（RT-PCR）and sequence comparison analysis were performed to detect the expression of Pde cDNAs and to assess the identity rates of cDNA and amino acid sequences between guinea pig and human or mouse,respectvely.The RT-PCR primers were located on the conserved region of human PDE and mouse Pde cDNAs.Results Eleven novel Pde cDNAs were detected in the brain of guinea pig（Cavia porcellus）,including CpPde1a,CpPde1b,CpPde2a,CpPde4a,CpPde4d,CpPde5a,CpPde6c,CpPde7b, CpPde8a,CpPde9a,and CpPde10a.The identity rates of the Pde cDNA sequences between guinea pig and human ranged from 83.8%to 94.3%,and those of the amino acid sequences ranged from 91.9%to 100%.The identity rates of Pde cDNA sequences between guinea pig and mouse ranged from 84.6%to 92.1%,and those of amino acid sequences ranged from 91.2% to 99.2%.The average identity rate of the 11 Pde cDNA sequences between guinea pig and human was significantly higher（P 0.01）than that between guinea pig and mouse.The putative partial amino acid sequences of guinea pig contained at least one of the conserved domains of human and mouse PDE proteins.Conclusion These results indicate that the brainexpressed Pde genes are identified in guinea pig,which lays the foundation for further investigating the physiological roles of PDE proteins in the brain.

Chinese herbal medicine enhances sexual function and c-Fos/nNOS expression in the nucleus accumbens of orchidectomized rats

OBJECTIVE: To determine whether the central nervous system is involved in the effect of Chinese herbal medicine on sexual function recovery in orchidectomized rats.METHODS: Orchidectomized rats were administered intragastrically with a decoction of "kidneynourishing" Chinese herbal medicine once per day for 28 days. Accessory genital organ weight, plasma testosterone, and mating behavior were investigated. The expression of c-Fos and neuronal nitric oxide synthase(n NOS) in neuronal cells in the nucleus accumbens(NAc) was analyzed by immunohistochemistry.RESULTS: There was a decrease in accessory genital organ weight, plasma testosterone, and sexual behavior, as well as a low number of c-Fos-positive cells and a large n NOS-positive cell area in orchidectomized rats. Administration of the herbal medicine increased accessory genital organ weight, testosterone level, mating behavior, and c-Fos-positive cell number, while it decreased the n NOS-positive cell area in orchidectomized rats.CONCLUSION: An increase of plasma testosterone after administration of "kidney-nourishing" herbal medicine might contribute to the elevated sexual function and activity in orchidectomized rats. In addition, a central nervous system mechanism, such as the functional alteration of NAc, might be involved.