Can the construction of low-carbon cities reduce haze pollution?

As a comprehensive environmental regulation, the low-carbon city pilot policy (LCCP) may have an impact on haze pollution. The evaluation of the effectiveness of LCCP on haze pollution is greatly significant for air pollution prevention and control. Taking LCCP as the starting point, in this study we constructed DID, PSM-DID, and intermediary effect models to empirically test the impact and mechanism of LCCP on haze pollution, based on the panel data of 271 cities in China from 2005 to 2018. The findings show that (1) LCCP has significantly reduced the urban haze pollution, and the average annual concentration of PM2.5 in pilot cities decreased by 14.29%. (2) LCCP can inhibit haze pollution by promoting technological innovation, upgrading the industrial structure, and reducing energy consumption. Among these impacts, the effect of technological innovation is the strongest, followed by industrial structure, and energy consumption. (3) LCCP has significantly curbed the haze pollution of non-resource dependent cities, Eastern cities, and large cities, but exerted little impact on resource-dependent cities, Central and Western regions, and small and medium-sized cities. (4) LCCP has a spatial spillover effect. It can inhibit the haze pollution of adjacent cities through demonstration and warning effects. This study enriches the relevant research on LCCP and provides empirical support and policy enlightenment for pollution reduction.

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Air Quality And Health Benefits of Increasing Carbon Mitigation Tech-Innovation In China

10.21203/rs.3.rs-800136/v1 ◽

2021 ◽

Author(s):

Shunlin Jin ◽

Weidong Wang ◽

Dragana Ostic ◽

Caijing Zhang ◽

Na Lu ◽

...

Keyword(s):

Air Quality ◽

Industrial Structure ◽

Health Benefits ◽

Low Carbon ◽

Carbon Mitigation ◽

Short Term ◽

Stirpat Model ◽

Haze Pollution ◽

Patent Applications

Abstract Most studies on the short-term local benefits of carbon mitigation technologies on air quality improvement and health focus on specific technologies such as biofuels or Carbon sequestration technologies, while ignoring the overall role of the growing scale of low-carbon technologies, and the relevant empirical studies are particularly lacking. Based on STIRPAT model and EKC hypothesis, this paper takes 30 provinces of China from 2004 to 2016 as research samples, measures the carbon mitigation tech-innovation(CMTI) with Y02 low carbon patent applications, and constructs a econometric model to empirically analyze the effect of carbon mitigation tech-innovation in response to climate change on the inhibition of haze pollution. It draws on relevant studies to quantify air quality and health benefits of carbon mitigation tech-innovation. Research shows that a 1% increase in the number of low-carbon patent applications can reduce haze pollution by 0.066%. According to this estimate, to 2029,China's carbon mitigation tech-innovation could reduce PM2.5 concentration to 15µg/m3 preventing 5.597million premature deaths. The research further found that carbon mitigation tech-innovation can also indirectly inhibit haze pollution by triggering more systematic economic structure changes such as energy and industrial structure. Additionally, the study found that the role of grey tech-innovation(GT) related to improving the efficiency of fossil energy is stronger than that of clean technology(CT) related to the use of renewable energy. This suggests that for a large economy such as China, where coal is still the dominant source of energy consumption, the short-term local benefits of improving air quality and health through the use of grey tech-innovation to improve energy and industrial structure are still important to balance the cost of carbon mitigation.

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S.E.M.-T.E.M. Image Comparison

Proceedings, annual meeting, Electron Microscopy Society of America ◽

10.1017/s0424820100064712 ◽

1971 ◽

Vol 29 ◽

pp. 132-133

Author(s):

G. M. Greene ◽

J. W. Sprys

Keyword(s):

Electron Microscope ◽

Low Carbon Steel ◽

Secondary Emission ◽

Low Carbon ◽

Preparation Time ◽

Actual Surface ◽

Fine Detail ◽

Transmission Electron ◽

Transmission Study ◽

Large Sections

The present study demonstrates that fracture surfaces appear strikingly different when observed in the transmission electron microscope by replication and in the scanning electron microscope by backscattering and secondary emission. It is important to know what form these differences take because of the limitations of each instrument. Replication is useful for study of surfaces too large for insertion into the S.E.M. and for resolution of fine detail at high magnification with the T.E.M. Scanning microscopy reduces sample preparation time and allows large sections of the actual surface to be viewed.In the present investigation various modes of the S.E.M. along with the transmission mode in the T.E.M. were used to study one area of a fatigue surface of a low carbon steel. Following transmission study of a platinum carbon replica in the T.E.M. and S.E.M. the replica was coated with a gold layer approximately 200A° in thickness to improve electron emission.

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Lattice Imaging of Twin, Lath and α/Martensite Boundaries in Duplex Low Carbon Steels

Proceedings, annual meeting, Electron Microscopy Society of America ◽

10.1017/s0424820100078195 ◽

1977 ◽

Vol 35 ◽

pp. 118-119

Author(s):

J. Y. Koo ◽

G. Thomas

Keyword(s):

High Resolution Electron Microscopy ◽

Ferrite Matrix ◽

Carbon Steels ◽

Bright Field Image ◽

Low Carbon ◽

Lattice Imaging ◽

Bright Field ◽

Lattice Image ◽

New Information ◽

Resolution Electron

High resolution electron microscopy has been shown to give new information on defects(1) and phase transformations in solids (2,3). In a continuing program of lattice fringe imaging of alloys, we have applied this technique to the martensitic transformation in steels in order to characterize the atomic environments near twin, lath and αmartensite boundaries. This paper describes current progress in this program.Figures A and B show lattice image and conventional bright field image of the same area of a duplex Fe/2Si/0.1C steel described elsewhere(4). The microstructure consists of internally twinned martensite (M) embedded in a ferrite matrix (F). Use of the 2-beam tilted illumination technique incorporating a twin reflection produced {110} fringes across the microtwins.

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Characterization of carbides in M50NiL

Proceedings, annual meeting, Electron Microscopy Society of America ◽

10.1017/s0424820100087343 ◽

1991 ◽

Vol 49 ◽

pp. 606-607

Author(s):

L. S. Lin ◽

K. P. Gumz ◽

A. V. Karg ◽

C. C. Law

Keyword(s):

Temperature Effects ◽

Base Composition ◽

Lattice Parameter ◽

Control Surface ◽

Carbide Formation ◽

Particle Sizes ◽

Low Carbon ◽

Fee Structure ◽

Heat Treated

Carbon and temperature effects on carbide formation in the carburized zone of M50NiL are of great importance because they can be used to control surface properties of bearings. A series of homogeneous alloys (with M50NiL as base composition) containing various levels of carbon in the range of 0.15% to 1.5% (in wt.%) and heat treated at temperatures between 650°C to 1100°C were selected for characterizations. Eleven samples were chosen for carbide characterization and chemical analysis and their identifications are listed in Table 1.Five different carbides consisting of M6C, M2C, M7C3 and M23C6 were found in all eleven samples examined as shown in Table 1. M6C carbides (with least carbon) were found to be the major carbide in low carbon alloys (<0.3% C) and their amounts decreased as the carbon content increased. In sample C (0.3% C), most particles (95%) encountered were M6C carbide with a particle sizes range between 0.05 to 0.25 um. The M6C carbide are enriched in both Mo and Fe and have a fee structure with lattice parameter a=1.105 nm (Figure 1).

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Thermomechanical Treatment of a 4340 Ni-Cr-Mo Alloy Steel

Proceedings, annual meeting, Electron Microscopy Society of America ◽

10.1017/s0424820100098083 ◽

1981 ◽

Vol 39 ◽

pp. 314-315 ◽

Cited By ~ 1

Author(s):

M.T. Jahn ◽

J.C. Yang ◽

C.M. Wan

Keyword(s):

Mechanical Property ◽

Chemical Composition ◽

Alloy Steel ◽

Thermomechanical Treatment ◽

Room Temperature ◽

Good Combination ◽

Thermal Treatments ◽

Low Carbon ◽

4340 Steel ◽

Good Improvement

4340 Ni-Cr-Mo alloy steel is widely used due to its good combination of strength and toughness. The mechanical property of 4340 steel can be improved by various thermal treatments. The influence of thermomechanical treatment (TMT) has been studied in a low carbon Ni-Cr-Mo steel having chemical composition closed to 4340 steel. TMT of 4340 steel is rarely examined up to now. In this study we obtain good improvement on the mechanical property of 4340 steel by TMT. The mechanism is explained in terms of TEM microstructures4340 (0.39C-1.81Ni-0.93Cr-0.26Mo) steel was austenitized at 950°C for 30 minutes. The TMTed specimen (T) was obtained by forging the specimen continuously as the temperature of the specimen was decreasing from 950°C to 600°C followed by oil quenching to room temperature. The thickness reduction ratio by forging is 40%. The conventional specimen (C) was obtained by quenching the specimen directly into room temperature oil after austenitized at 950°C for 30 minutes. All quenched specimens (T and C) were then tempered at 450, 500, 550, 600 or 650°C for four hours respectively.

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The microstructure change of low-carbon electrical steels by residual aluminum

Proceedings, annual meeting, Electron Microscopy Society of America ◽

10.1017/s0424820100153403 ◽

1989 ◽

Vol 47 ◽

pp. 286-287

Author(s):

C.K. Hou ◽

C.T. Hu ◽

Sanboh Lee

Keyword(s):

Annealing Treatment ◽

Low Carbon ◽

Electrical Steels ◽

Vacuum Degassing ◽

Spherical Inclusions ◽

Residual Aluminum ◽

Average Grain Size ◽

The Matrix ◽

Fine Size ◽

To Come

The fully processed low-carbon electrical steels are generally fabricated through vacuum degassing to reduce the carbon level and to avoid the need for any further decarburization annealing treatment. This investigation was conducted on eighteen heats of such steels with aluminum content ranging from 0.001% to 0.011% which was believed to come from the addition of ferroalloys.The sizes of all the observed grains are less than 24 μm, and gradually decrease as the content of aluminum is increased from 0.001% to 0.007%. For steels with residual aluminum greater than 0. 007%, the average grain size becomes constant and is about 8.8 μm as shown in Fig. 1. When the aluminum is increased, the observed grains are changed from the uniformly coarse and equiaxial shape to the fine size in the region near surfaces and the elongated shape in the central region. SEM and EDAX analysis of large spherical inclusions in the matrix indicate that silicate is the majority compound when the aluminum propotion is less than 0.003%, then the content of aluminum in compound inclusion increases with that in steel.

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Precipitation at the transformation interface of pearlite in steel

Proceedings, annual meeting, Electron Microscopy Society of America ◽

10.1017/s0424820100177696 ◽

1990 ◽

Vol 48 (4) ◽

pp. 912-913

Author(s):

F. A. Khalid ◽

D. V. Edmonds

Keyword(s):

Thin Foil ◽

Carbon Steels ◽

Model Alloy ◽

Low Carbon ◽

High Carbon ◽

Growth Interface ◽

Medium Carbon ◽

Interphase Precipitation ◽

Solution Treated ◽

Wide Range

The austenite/pearlite growth interface in a model alloy steel (Fe-1lMn-0.8C-0.5V nominal wt%) is being studied in an attempt to characterise the morphology and mechanism of VC precipitation at the growth interface. In this alloy pearlite nodules can be grown isothermally in austenite that remains stable at room temperature thus facilitating examination of the transformation interfaces. This study presents preliminary results of thin foil TEM of the precipitation of VC at the austenite/ferrite interface, which reaction, termed interphase precipitation, occurs in a number of low- carbon HSLA and microalloyed medium- and high- carbon steels. Some observations of interphase precipitation in microalloyed low- and medium- carbon commercial steels are also reported for comparison as this reaction can be responsible for a significant increase in strength in a wide range of commercial steels.The experimental alloy was made as 50 g argon arc melts using high purity materials and homogenised. Samples were solution treated at 1300 °C for 1 hr and WQ. Specimens were then solutionised at 1300 °C for 15 min. and isothermally transformed at 620 °C for 10-18hrs. and WQ. Specimens of microalloyed commercial steels were studied in either as-rolled or as- forged conditions. Detailed procedures of thin foil preparation for TEM are given elsewhere.

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