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71.
The relevance of analyzing effects of environmental regulation on innovation cannot be overemphasized. In this paper, we first develop a theoretical model to predict how command-and-control environmental regulation affects innovation, and then we derive its channels. Using the difference-in-difference-in-differences strategy and a comprehensive dataset at city-industry-year level of manufacturing sectors in China, we found that the more stringent environmental regulations that are faced by cities, measured by the reduction targets of chemical oxygen demand (COD) and sulfur dioxide (SO2) during the eleventh Five-Year Plan, are negatively associated with innovation. Thus, the evidence contradicts the Porter Hypothesis. On average, a one standard deviation increase in the reduction targets of COD (SO2) is associated with a 0.023 (0.016) standard deviation decrease in the innovation index. We controlled carefully for various potential confounders, and the results were supported by robustness and falsification checks. There exists an evident heterogeneity effect across regions and industries with different pollution intensities. The channel analysis shows that stricter environmental regulation also accounts for a sharp decline in labor demand, firm entry, and inbound foreign direct investment. Our findings are also robust to alternative measures for innovation and environmental regulation. 相似文献
72.
Since 1994, the Rumuruti (R) chondrites have been recognized as a new, well-established chondrite group differing from carbonaceous, ordinary, and enstatite chondrites. The first R chondrite, Carlisle Lakes, was found in Australia in 1977. Meanwhile, the number has increased to 107 (December, 2010). This group is named after the Rumuruti meteorite, the first and so far the only R chondrite fall. Most of the R chondrites are breccias containing a variety of different clasts embedded in a clastic matrix. Some textural and mineralogical characteristics can be summarized as follows: (a) the chondrule abundance in large fragments and in unbrecciated rocks is ∼35–50 vol%; (b) Ca,Al-rich inclusions are rare; (c) the olivine abundance is typically 65–78 vol%; (d) the mean chondrule diameter is ∼400 μm; (e) in unequilibrated R chondrites, low-Ca pyroxene is dominating, whereas in equilibrated R chondrites it is Ca-rich pyroxene; (f) the typical olivine in a metamorphosed lithology is ∼Fa38–40; (g) matrix olivine in unequilibrated, type 3 fragments and rocks has much higher Fa (∼45–60 mol%) compared to matrix olivines in type 4–6 lithologies (∼Fa38–41); (h) spinels have a high TiO2 of ∼5 wt%; (i) abundant different noble metal-bearing phases (metals, sulfides, tellurides, arsenides) occur. The exception is the metamorphosed, type 5/6 R chondrite La Paz Icefield 04840 which contains hornblende, phlogopite, and Ca-poor pyroxene, the latter phase typically occurring in low-grade metamorphosed R chondrites only.In bulk composition, R chondrites have some affinity to ordinary chondrites: (a) the absence of significant depletions in Mn and Na in R chondrites and ordinary chondrites is an important feature to distinguish these groups from carbonaceous chondrites; (b) total Fe (∼24 wt%) of R chondrites is between those of H and L chondrites (27.1 and 21.6 wt%, respectively); (c) the average CI/Mg-normalized lithophile element abundances are ∼0.95 × CI, which is lower than those for carbonaceous chondrites (≥1.0 × CI) and slightly higher than those for ordinary chondrites (∼0.9 × CI); (d) trace element concentrations such as Zn (∼150 ppm) and Se (∼15 ppm) are much higher than in ordinary chondrites; (e) the whole rock Δ17O of ∼2.7 for R chondrites is the highest among all meteorite groups, and the mean oxygen isotope composition is δ17O = 5.36 ± 0.43, δ18O = 5.07 ± 0.86, Δ17O = +2.72 ± 0.31; (f) noble gas cosmic ray exposure ages of R chondrites range between ∼0.1 and ∼70 Ma. More than half of the R chondrites analyzed for noble gases contain implanted solar wind and, thus, are regolith breccias. The 43 R chondrites from Northern Africa analyzed so far for noble gases seem to represent at least 16 falls. Although the data base is still scarce, the data hint at a major collision event on the R chondrite parent body between 15 and 25 Ma ago. 相似文献
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使用R-矩阵方法,采用三态密耦图像计算了类锂离子C^3+激发态1s^22p^2P的光电离截面,并给出了不同过程及不同分波的截面。计算结果揭示了光电离过程中的Rydberg系列共振。 相似文献
76.
M. Kun † J. Vinkó ‡ L. Szabados 《Monthly notices of the Royal Astronomical Society》2000,319(3):777-790
In order to reveal the star-forming history of the molecular cloud complex we studied the intermediate mass stellar population in the Cepheus Flare region. (Paper I dealt with the distance and the young stellar object candidates of the region.) Correlating the IRAS Point Source Catalogue and Faint Source Catalogue positions with those of 1214 B8–A8 and 1760 F0–F5 type stars brighter than and classified during an objective prism survey, we identified 19 stars showing far-infrared excess emission in the Cepheus Flare region. In addition to the 16 stars whose counterparts are given in the IRAS catalogues, we found three more stars with infrared excess not recognized before. In order to identify the young medium-mass stars associated with the Cepheus Flare molecular clouds we observed the optical spectra of the IR-excess stars, and using published optical photometry and the IRAS data we examined their spectral energy distributions (SEDs) and IRAS two-colour diagram. The observations resulted in the discovery of a new Herbig Ae/Be star, BD +68°1118, coinciding with IRAS 21169+6842. More evolved HAe/Be stars may be SAO 19953, BD +67°1314 and BD +69°1231, whose H α lines showed weak emission components. Possible β Pictoris- or Vega-type stars may be HD 203854, HD 212826 and HD 216486, whereas the far-infrared fluxes at the positions of BD +72°1018, HD 210806 and HD 217903 can be attributed to the heating of the interstellar environment. We used distances and radial velocities of the stars derived from the spectroscopy and published optical photometry as indicators of their relations to the clouds. Information on the environment of the observed stars deduced from the diffuse interstellar band at λ 6613 is briefly discussed. 相似文献
77.
A. P. Jacob T. R. Bedding J. G. Robertson M. Scholz 《Monthly notices of the Royal Astronomical Society》2000,312(4):733-746
We discuss the wavelength dependence of angular diameters of M giants from an observational perspective. Observers cannot directly measure an optical-depth radius for a star, despite this being a common theoretical definition. Instead, they can use an interferometer to measure the square of the fringe visibility. We present new plots of the wavelength-dependent centre-to-limb variation (CLV) of intensity of the stellar disc as well as visibility for Mira and non-Mira M giant models. We use the terms 'CLV spectra' and 'visibility spectra' for these plots. We discuss a model-predicted extreme limb-darkening effect (also called the narrow-bright-core effect) in very strong TiO bands which can lead to a misinterpretation of the size of a star in these bands. We find no evidence as yet that this effect occurs in real stars. Our CLV spectra can explain the similarity in visibilities of R Dor (M8IIIe) that have been observed recently, despite the use of two different passbands. We compare several observations with models, and find that the models generally underestimate the observed variation in visibility with wavelength. We present CLV and visibility spectra for a model that is applicable to the M supergiant α Ori. 相似文献
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79.
西昆仑山甜水海钻孔氧化铁指标的R/S分析及其意义 总被引:17,自引:0,他引:17
运用R/S分析法,对经过等时处理的甜水海钻孔氧化铁3项指标FeO、Fe2O3及其比值FeO/Fe2O3进行了分析计算,其指标都存在明显的Hurst现象,Hurst指数H分别为:Fe2O3为0.76,FeO为0.85,FeO/Fe2O3为0.65,它们都大于0.5。反映了该地区过去20多万年来气候环境变化存在持续性。3者Hurst指数存在差异的原因目前还不清楚,可能说明它们反映气候环境演化持续性强度 相似文献
80.
选取史灌河流域上游黄泥庄站以上集水区域为研究流域,以地面站点观测为基准数据,评估TRMM 3B42V7版本卫星降水数据的精度,并采用上述两种降水数据驱动栅格型新安江模型,模拟黄泥庄站日径流和月径流过程。结果表明:2001~2010年TRMM 3B42V7降水数据与雨量站数据累积量的偏差不大,仅为1.71%,但相关系数较低,采用TRMM降水数据模拟的日径流能基本再现黄泥庄站的日径流过程,但对洪峰的模拟精度较低;TRMM月降水数据精度较高,相关系数为0.96,能够较为精确地模拟黄泥庄站的月径流过程。 相似文献