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1.
Surg Endosc ; 36(12): 8893-8907, 2022 12.
Artículo en Inglés | MEDLINE | ID: mdl-35906460

RESUMEN

BACKGROUND: There is still controversy over whether to perform laparoscopic surgery for T3 stage gallbladder cancer. In addition, the necessity of segment 4b+5 liver resection for stage T3 gallbladder has not been reported. This article aims to explore the safety, effectiveness, and short-term prognosis of laparoscopic segment 4b+5 liver resection for T3 stage gallbladder cancer. METHODS: This is a retrospective multicenter propensity score-matched study. Disease-free survival, perioperative complications, and intraoperative safety were analyzed to evaluate safety and effectiveness. RESULTS: There was no significant difference in the incidence of intraoperative bleeding, number of lymph nodes obtained, postoperative complications, or disease-free survival (DFS) between the open group (OG) and laparoscopic group (LG) (P > 0.05). The DFS time of the S4b+5 resection group (S4b5) was longer than that of the wedge group (P = 0.016). Cox regression showed that positive margins (HR, 5.32; 95% CI 1.03-27.63; P = 0.047), lymph node metastasis (HR, 2.70; 95% CI 1.31-5.53; P = 0.007), and liver S4b+5 resection (HR, 0.30; 95% CI 0.14-0.66; P = 0.003) were independent risk factors for DFS. The operative time of indocyanine green (ICG) fluorescence-guided liver S4b5 segment resection was shorter than that of traditional laparoscopic S4b+5 resection guided by hepatic veins (P ≤ 0.001). CONCLUSION: Laparoscopic liver S4b+5 resection for T3 stage gallbladder cancer is safe and feasible and can prolong DFS. ICG fluorescence-guided negative staining may reduce the difficulty of the operation.


Asunto(s)
Carcinoma in Situ , Neoplasias de la Vesícula Biliar , Laparoscopía , Humanos , Neoplasias de la Vesícula Biliar/patología , Hepatectomía/efectos adversos , Metástasis Linfática , Estudios Retrospectivos , Carcinoma in Situ/cirugía , Hígado/patología
2.
J Cell Biochem ; 120(2): 1232-1244, 2019 Feb.
Artículo en Inglés | MEDLINE | ID: mdl-30216493

RESUMEN

Cardiac fibrosis is known to be present in dilated cardiomyopathy (DCM) and it predicts the occurrence of sudden death and congestive heart failure. The aim of our study is to investigate the expression of microRNA-132 (miR-132) and its effect on cardiocyte proliferation, apoptosis, and cardiac fibrosis by binding to phosphatase and tensin homolog (PTEN) through the phosphateidylinositol 3-kinase (PI3K)/protein kinase (Akt) signal transduction pathway in DCM rats. DCM rat models induced by doxorubicin were established and confirmed by an ultrasonic cardiogram. Epithelial cells were treated with inhibitors, activators, and small interfering RNAs to identify the mechanisms by which miR-132 controls cardiocyte activity and cardiac fibrosis. Angiotensin II (Ang II) and aldosterone (ALD) expressions were detected by an enzyme-linked immunosorbent assay. The relationship between PTEN and miR-132 was verified by a dual-luciferase reporter assay. Cell proliferation and apoptosis were tested by the MTT assay and flow cytometry. PTEN was determined to be the target gene of miR-132. Rat models of DCM exhibited a lower level of miR-132, PI3K, Akt, B-cell lymphoma 2, collagen I, and collagen III, but a higher level of PTEN, Bcl-2-associated X protein, and proliferating cell nuclear antigen as well as inflammatory response (Ang II and ALD), accompanied by declined cardiocyte proliferation and elevated apoptosis and cardiac fibrosis. Upregulated miR-132 or silenced PTEN activated the PI3K/Akt pathway, thus facilitating cardiocyte proliferation and repressing cardiocyte apoptosis and cardiac fibrosis, as well as inflammatory responses. Downregulated miR-132 reversed this tendency. These findings indicate that miR-132 activates the PI3K/Akt pathway by inhibiting PTEN expression, thus facilitating cardiocyte proliferation and inhibiting apoptosis and cardiac fibrosis in DCM rats.

3.
Small ; 15(18): e1805493, 2019 05.
Artículo en Inglés | MEDLINE | ID: mdl-30945787

RESUMEN

Flexible devices integrated with sensing and energy storage functions are highly desirable due to their potential application in wearable electronics and human motion detection. Here, a flexible film is designed in a facile and low-cost leaf templating process, comprising wrinkled carbon nanotubes (CNTs) as the conductive layer and patterned polydimethylsiloxane (PDMS) with bio-inspired microstructure as a soft substrate. Assembled from wrinkled CNTs on patterned PDMS film, a strain sensor is realized to possess sensitive resistance response against various deformations, producing a resistance response of 0.34%, 0.14%, and 9.1% under bending, pressing, and 20% strain, respectively. Besides, the strain sensor can reach a resistance response of 3.01 when stretched to 44%. Furthermore, through the electro-deposition of polyaniline, the CNTs film is developed into a supercapacitor, which exhibits a specific capacitance of 176 F g-1 at 1 A g-1 and a capacitance retention of 88% after 10 000 cycles. In addition, the fabricated supercapacitor shows super flexibility, delivering a capacitance retention of 98% after 180° bending for 100 cycles, 95% after 45° twisting for 100 cycles, and 98% after 100% stretching for 400 cycles. The superior capacitance stability demonstrates that the design of wrinkled CNTs-based electrodes fixed by microstructures is beneficial to the excellent electrochemical performance.

4.
Macromol Rapid Commun ; 40(7): e1800896, 2019 Apr.
Artículo en Inglés | MEDLINE | ID: mdl-30811751

RESUMEN

Inspired by the motions of plant tissues in response to external stimuli, significant attention has been devoted to the development of actuating polymeric materials. In particular, polymeric actuators driven by organic molecules have been designed due to their combined superiorities of tunable functional monomers, designable chemical structures, and variable structural anisotropy. Here, the recent progress is summarized in terms of material synthesis, structure design, polymer-solvent interaction, and actuating performance. In addition, various possibilities for practical applications, including the ability to sense chemical vapors and solvent isomers, and future directions to satisfy the requirement of sensing and smart systems are also highlighted.


Asunto(s)
Compuestos Orgánicos/química , Polímeros/síntesis química , Estructura Molecular , Polímeros/química
5.
Angew Chem Int Ed Engl ; 57(50): 16436-16441, 2018 Dec 10.
Artículo en Inglés | MEDLINE | ID: mdl-30334306

RESUMEN

Two-dimensional (2D) carbon hybrids have promise in various areas such as energy storage and catalysis. Simple methods for controllable fabrication of 2D graphitic carbon hybrids in a scalable manner remains challenging. Now, a microwave-assisted strategy for mass production of 2D carbon hybrids based on self-boosting catalytic carbonization of a metal-agarose framework is demonstrated. Hybrids including hollow Fe3 C nanoparticles, Ni/Co nanoparticles, and hollow FeOx nanoparticles uniformly embedded in 2D graphitic carbon nanosheets (GCNs) are obtained, demonstrating the generality of the approach. Metal-polymer coordination and microwave-enabled fast catalytic decomposition of precursors play vital roles in facilitating the formation of the nanosheet structure. The resulting FeOx -GCNs hybrid exhibits superior lithium-storage performance (1118 mAh g-1 at 500 mA g-1 and 818 mAh g-1 at 2000 mA g-1 after 1200 cycles).

6.
Chemistry ; 22(24): 8368-75, 2016 06 06.
Artículo en Inglés | MEDLINE | ID: mdl-27116117

RESUMEN

We report a unique strategy to obtain the bifunctional heterogeneous catalyst TBB-Bpy@Salen-Co (TBB=1,2,4,5-tetrakis(bromomethyl)benzene, Bpy=4,4'-bipyridine, Salen-Co=N,N'-bis({4-dimethylamino}salicylidene)ethylenediamino cobalt(III) acetate) by combining a cross-linked ionic polymer with a Co(III) -salen Schiff base. The catalyst showed extra high activity for CO2 fixation under mild, solvent-free reaction conditions with no requirement for a co-catalyst. The synthesized catalyst possessed distinctive spherical structural features, abundant halogen Br(-) anions with good leaving group ability, and accessible Lewis acidic Co metal centers. These unique features, together with the synergistic role of the Co and Br(-) functional sites, allowed TBB-Bpy@Salen-Co to exhibit enhanced catalytic conversion of CO2 into cyclic carbonates relative to the corresponding monofunctional analogues. This catalyst can be easily recovered and recycled five times without significant leaching of Co or loss of activity. Moreover, based on our experimental results and previous work, a synergistic cycloaddition reaction mechanism was proposed.


Asunto(s)
Dióxido de Carbono/química , Cobalto/química , Compuestos Epoxi/química , Etilenodiaminas/química , Microesferas , Polímeros/química , Derivados del Benceno/química , Catálisis , Reacción de Cicloadición , Iones/química , Nitrilos/química , Piridinas/química , Bases de Schiff/química , Espectroscopía Infrarroja por Transformada de Fourier
7.
Environ Sci Pollut Res Int ; 31(17): 25508-25523, 2024 Apr.
Artículo en Inglés | MEDLINE | ID: mdl-38472581

RESUMEN

Quantifying the drivers of water footprint evolution in the Yangtze River Delta is vital for the optimization of China's total water consumption. The article aims to decompose and predict the water footprint of the Yangtze River Delta and provide policy recommendations for optimizing water use in the Yangtze River Delta. The paper applies the LMDI method to decompose the water footprint of the Yangtze River Delta and its provinces into five major drivers: water footprint structure, water use intensity, R&D scale, R&D efficiency, and population size. Furthermore, this paper combines scenario analysis and Monte Carlo simulation methods to predict the potential evolution trends of water footprint under the basic, general, and enhanced water conservation scenario, respectively. The results show that (1) the expansion of R&D scale is the main factor promoting the growth of water footprint, the improvement of R&D efficiency, and the reduction of water intensity are the main factors inhibiting the increase of water footprint, and the water footprint structure and population size have less influence on water footprint. (2) The evolution trend of water footprint of each province under three scenarios is different. Compared to the basic scenario, the water footprint decreases more in Shanghai, Zhejiang, and Anhui under the general and enhanced water conservation scenario. The increase in water footprint in Jiangsu under the enhanced scenario is smaller than that of the general water conservation scenario.


Asunto(s)
Conservación de los Recursos Hídricos , Ríos , China , Agua , Predicción , Desarrollo Económico
8.
ACS Appl Mater Interfaces ; 16(29): 37963-37971, 2024 Jul 24.
Artículo en Inglés | MEDLINE | ID: mdl-38984437

RESUMEN

Dodecahydro-N-ethylcarbazole (12H-NEC) is regarded as the most promising liquid organic hydrogen carrier for hydrogen storage and transportation. Understanding the mechanism of 12H-NEC dehydrogenation and developing cost-effective catalysts are significant. Pd is a high-performance catalyst for 12H-NEC but is not cost-effective, and Ni is just the opposite. How to understand the whole process of full dehydrogenation and improve the performance of Ni become two key questions. Herein, we systematically investigated the mechanism of the full dehydrogenation of 12H-NEC on Pd(111) and Ni(111) for the first time. By calculating all the barriers in the whole dehydrogenation process, we identified that 3H-NEC to 2H-NEC is the rate-determining step and Ni is catalytically less effective than Pd, which is attributed to its narrower d-band distribution and a 0.32 eV higher d-band center than that of Pd. To improve the performance of Ni, we further introduced dopants of Au, Ag, Cu, Pd, Pt, Ru, Rh, Zn, and Al. We found that Ag doping brings a downshift of the d-band center from -1.29 to -1.67 eV and reduces the barrier of 4H-NEC to NEC from 0.94 to 0.76 eV. This study provides new insights into the catalytic mechanism and performance-tuning strategy to help future experimental synthesis.

9.
ACS Appl Mater Interfaces ; 16(28): 36444-36452, 2024 Jul 17.
Artículo en Inglés | MEDLINE | ID: mdl-38963298

RESUMEN

Metal-organic frameworks (MOFs) are one of the most promising hydrogen-storing materials due to their rich specific surface area, adjustable topological and pore structures, and modified functional groups. In this work, we developed automatically parallel computational workflows for high-throughput screening of ∼11,600 MOFs from the CoRE database and discovered 69 top-performing MOF candidates with work capacity greater than 1.00 wt % at 298.5 K and a pressure swing between 100 and 0.1 bar, which is at least twice that of MOF-5. In particular, ZITRUP, OQFAJ01, WANHOL, and VATYIZ showed excellent hydrogen storage performance of 4.48, 3.16, 2.19, and 2.16 wt %. We specifically analyzed the relationship between pore-limiting diameter, largest cavity diameter, void fraction, open metal sites, metal elements or nonmetallic atomic elements, and deliverable capacity and found that not only geometrical and physical features of crystalline but also chemical properties of adsorbate sites determined the H2 storage capacity of MOFs at room temperature. It is highlighted that we first proposed the modified crystal graph convolutional neural networks by incorporating the obtained geometrical and physical features into the convolutional high-dimensional feature vectors of period crystal structures for predicting H2 storage performance, which can improve the prediction accuracy of the neural network from the former mean absolute error (MAE) of 0.064 wt % to the current MAE of 0.047 wt % and shorten the consuming time to about 10-4 times of high-throughput computational screening. This work opens a new avenue toward high-throughput screening of MOFs for H2 adsorption capacity, which can be extended for the screening and discovery of other functional materials.

10.
Environ Sci Pollut Res Int ; 30(9): 22843-22862, 2023 Feb.
Artículo en Inglés | MEDLINE | ID: mdl-36308660

RESUMEN

The turning point of China's total water consumption is very important for the understanding of the evolution trend of total water consumption and the formulation of water conservation policies. Based on the environmental Kuznets curve (EKC) model, this paper verifies the shape of water consumption Kuznets curve. Scenario analysis and Monte Carlo simulation are combined for the first time to predict water consumption Kuznets curve. The LMDI model is used to decompose the driving factors of the evolution of total water consumption, and the STIRPAT model is expanded to explore the influence mechanism of total water consumption. The results show the following: (1) The theoretical water consumption Kuznets curve exists, and the turning point is 26,448 yuan RMB (in around 2013). (2) Based on the multiple driving factors (water intensity, per capita GDP, and population) and multiple scenarios (baseline scenario, target scenario, and 2 adjusted scenarios), 32 scenarios are designed in this paper; in the S1-S8, the turning point still appeared near 2013; the curves under the S11-S14, S16, and S25-S32 were inverted U-shaped, and the turning point was 48,728 yuan RMB (in around 2025); and in the S9, S10, and S15, the curve shows an upward trend; in the S17-S24, the curve has a rising-falling-rising characteristic. (3) Domestic effect and ecological effect both play a role in promoting the total water consumption, while the production effect is in an inverted N-shaped. Economic growth has always promoted the increase in industrial and agricultural water consumption, and the role of population size is relatively weak. The intensity of production water consumption has always promoted reduction in industrial and agricultural water consumption. Industrial water intensity and industrial structure are the primary and secondary factors that promote the decline of production intensity. (4) The per capita GDP has the largest contribution to total water consumption, followed by the water intensity, and the industrial structure has the least impact. The population has a negative impact. Based on this, a number of policy implications are obtained.


Asunto(s)
Ingestión de Líquidos , Modelos Teóricos , Desarrollo Económico , Agua , China , Dióxido de Carbono/análisis
11.
Environ Sci Pollut Res Int ; 30(57): 120422-120460, 2023 Dec.
Artículo en Inglés | MEDLINE | ID: mdl-37945957

RESUMEN

Decoupling economic growth from electricity consumption is essential for energy conservation and emission reduction. Firstly, this paper applies the LMDI decomposition model to analyze the driving factors of electricity consumption in the Yangtze River Delta region. Secondly, scenario analysis and Monte Carlo technique are combined to research the evolutionary trend of electricity consumption from 2020 to 2035, so as to further analyze the decoupling state. Finally, using nonparametric kernel density estimation, this paper studies the evolution trend of decoupling state from 2005 to 2035. The results show that (1) economic growth is the main factor that promotes the increase of total electricity consumption. Domestic intensity and population scale contribute to the increase in total electricity consumption. The primary factor inhibiting the increase of total electricity consumption is production intensity, while industrial structure and urbanization level contribute to the decrease in total electricity consumption. (2) From 2005 to 2035, the decoupling level has been optimizing on the whole, and the internal gap has also reduced, but there still exists obvious internal gap. (3) Under the three scenarios, the evolution trend of production and domestic electricity consumption is the same. During 2020-2035, the production and domestic electricity consumption both show an increasing trend, with the total electricity consumption under the baseline scenario being the highest, followed by the general and the enhanced electricity-saving scenario. Combined with the empirical results of this paper, some policy recommendations are proposed.


Asunto(s)
Carbono , Desarrollo Económico , Carbono/análisis , Urbanización , China , Electricidad , Dióxido de Carbono/análisis
12.
Environ Sci Pollut Res Int ; 30(30): 75629-75654, 2023 Jun.
Artículo en Inglés | MEDLINE | ID: mdl-37222887

RESUMEN

As the largest energy consumer, China's control of carbon emissions from energy consumption plays a pivotal role in world climate governance. However, few studies have been conducted to explore the emission reduction pathways that promote a high level of synergy between China's economic growth and the " carbon peaking and carbon neutrality " goal from the perspective of energy consumption. Based on the measurement of energy consumption carbon emissions, this paper reveals the spatial and temporal distribution and evolution trends of carbon emissions in China at the national-provincial level. The multi-dimensional socio-economic factors such as R&D and urbanization are taken into account, and the LMDI model is used to decompose the driving effects of energy consumption carbon emissions at the national-provincial levels. Further, this paper combines the Tapio decoupling index with the LMDI model to decompose the decoupling states of China year by year and at the provincial level in four periods to explore the reasons for the change of carbon decoupling states. The results show that: (1) China's energy consumption carbon emissions grew at a high rate before 2013, and slowed down after that. There are significant differences in the scale and growth rate of carbon emissions among provinces, which can be classified into four types accordingly. (2) The R&D scale effect, urbanization effect, and population scale effect are the factors driving the growth of China's carbon emissions; while the energy structure effect, energy consumption industry structure effect, energy intensity effect, and R&D efficiency effect inhibit the growth of China's carbon emissions. (3) Weak decoupling is the most dominant decoupling state in China from 2003 to 2020, and the decoupling state varies significantly among provinces. According to the conclusions, this paper proposes targeted policy recommendations based on China's energy endowment.


Asunto(s)
Huella de Carbono , Desarrollo Económico , Carbono/análisis , Dióxido de Carbono/análisis , China , Urbanización
13.
Environ Sci Pollut Res Int ; 29(52): 78345-78360, 2022 Nov.
Artículo en Inglés | MEDLINE | ID: mdl-35690704

RESUMEN

The low-carbon development of power industry is the key to low-carbon development of the whole society. In order to determine appropriate and feasible emission reduction policies, it is necessary to identify the contribution of different drivers to the change of carbon emissions in China's power sector and to simulate the potential evolution trend of carbon emissions. This paper constructs LMDI model to analyze the driving factors of carbon emission changes in China's power industry from 2000 to 2018 and uses Monte Carlo algorithm to simulate the evolution trend of carbon emission under different scenarios. We can find (1) economic output effect reached 3.817 billion tons from 2000 to 2018, which was the primary factor to increase the carbon emission. Population scale effect reached 251million tons, which had a weak promotion impact on carbon emission. (2) Conversion efficiency effect played a role in restraining carbon emissions, reaching 699 million tons from 2000 to 2018. (3) Emission factor effect and power intensity effect have obvious volatility. The power structure effect showed great volatility before 2013 and mainly played a role in restraining carbon emission after 2013. (4) Under the baseline scenario, the carbon emission of China's power industry shows a growth trend. Under green development scenario and enhanced carbon reduction scenario, the carbon emission shows a trend of first increasing and then decreasing.


Asunto(s)
Dióxido de Carbono , Carbono , Carbono/análisis , Dióxido de Carbono/análisis , Industrias , China , Desarrollo Económico
14.
Micromachines (Basel) ; 13(3)2022 Feb 26.
Artículo en Inglés | MEDLINE | ID: mdl-35334662

RESUMEN

In the theory of traditional Chinese medicine, acupoints refer to special points and areas on the meridian line of the human body. Traditional Chinese medicine believes that the application of unique techniques such as pressing, kneading, rubbing, pushing, and patting to acupoints or massage with the help of specific tools has the effects of promoting blood circulation, dredging meridians, and eliminating fatigue. At present, most automatic massage devices are for large-area massage of the trunk, and few are specifically for acupoint massage of the limbs. First, this paper analyzes the characteristics of traditional Chinese medical acupoint massage and then obtains the design index of an automatic acupoint massage device. After that, based on the principle of a series elastic actuating mechanism, a flexible uni-acupoint massage device and control system, imitating the acupoint massage technique of traditional Chinese medicine, were designed. In order to analyze the massage force of the massage device, the man-machine contact dynamic model of the massage device was established, and the force of the massage device was simulated and analyzed. Finally, an experimental platform was built to verify the massage force and massage process of the massage device. The experimental results show that the massage device designed in this paper meets the indexes of traditional Chinese medical massage, in terms of the massage process and massage force, and verify the rationality of the design.

15.
Environ Sci Pollut Res Int ; 28(15): 19325-19350, 2021 Apr.
Artículo en Inglés | MEDLINE | ID: mdl-33394403

RESUMEN

With the development of China's economy, pollution has made serious impact on environment and human health. However, environmental protection and residents' health are becoming more and more important along with the country's social and economic transformation. Most existing studies have analyzed the path of economic impact on the environment and the production, pollution, and health in isolation. This research takes panel data of 30 provinces in China (including autonomous regions and municipalities, excluding Tibet, Hong Kong, Macau, and Taiwan) spanning 2014 to 2017 as an example, builds an evaluation indicator system on the basis of the three stages of economic production, wastewater treatment, and human health, and uses the undesirable three-stage dynamic data envelopment analysis model to empirically evaluate the total efficiency, stage efficiency, and the efficiency of various indicators. The research results show the average efficiency of the three stages in most provinces in four years is below 0.5, indicating the poor coordination of each stage; the efficiency gaps among the eastern, central, and western regions are very large because of the resource endowments, geographical environment, industrial structure, strategic adjustment, and other infactors. The total efficiency of the three stages of production input, wastewater treatment, and health output in the eastern region are higher than that of the central region and the western region. From the perspective of stage efficiency, most of the 30 provinces exhibit production efficiency < health efficiency < wastewater treatment efficiency. For the three-phase input and output indicators, the efficiency values and development trends of different provinces vary. The efficiencies of input variables in the wastewater treatment stage and health stage are low in most provinces. This means that the provinces should implement accurate policies according to their own evaluation results and improve the relevance and coordination among the three stages through reasonable allocation of medical input and arrangement of urban employment.


Asunto(s)
Aguas Residuales , Recursos Hídricos , China , Ciudades , Hong Kong , Humanos , Macao , Desarrollo Sostenible , Taiwán , Tibet
16.
Environ Sci Pollut Res Int ; 28(35): 48638-48655, 2021 Sep.
Artículo en Inglés | MEDLINE | ID: mdl-33928497

RESUMEN

The current water shortage in China is critical. Moreover, the water shortage has become the main bottleneck hindering sustainable economic growth. Against the background of China's dual control target of total water use and intensity, we choose the Yangtze River Delta (YRD) region as a research object, which encompasses Shanghai, Jiangsu, Zhejiang, and Anhui. Based on the perspective of water-energy-food nexus, we employ the generalized Divisia index method to decompose the change of water use into eight factors, regional economic scale effect, regional energy use scale effect, regional food production effect, regional water technology effect, regional energy technology effect, regional water-energy nexus effect, regional food-energy nexus effect, and regional water technology for food production effect, and analyze the contribution of each driver to identify the key drivers of total water use control. The results showed that the top four influencing factors are GDP, water intensity, energy consumption, and water-energy nexus in the YRD region. Regional economic scale is the first driving factor for increasing water use in the YRD region except for Zhejiang. Water intensity is the primary driving force of water-saving in Zhejiang. Energy consumption is the third driver of increasing water use in Jiangsu and Anhui. The effect of water-energy nexus is the third driving factor that affects the change of water use in Shanghai and Zhejiang. The authorities in the YRD region should vigorously develop water and energy utilization technologies to increase the water intensity and decrease energy consumption. The energy sector should decrease the water use to decrease the water-energy nexus which is also the main driving factor affecting the change of water use.


Asunto(s)
Ingestión de Líquidos , Agua , China , Desarrollo Económico , Ríos
17.
ACS Omega ; 6(4): 2813-2823, 2021 Feb 02.
Artículo en Inglés | MEDLINE | ID: mdl-33553899

RESUMEN

Supercritical carbon dioxide (SC-CO2) has been progressively used in the development of shale oil and gas. However, the interaction between CO2 and shale can change the mineral composition and the pore structure, thus affecting the mechanical properties of shale. To study the influence of SC-CO2 on shale, shale samples collected from the Songliao Basin in China are treated with SC-CO2 at various time intervals. Then, a series of tests are performed, such as the mineral composition analysis test, the pore structure analysis test, and the macro mechanics test. The results show that the mechanical properties of shale gradually decrease exponentially with the increase of SC-CO2 treatment time. The loss of elastic modulus reaches about 47% after the treatment of 14 d. X-ray diffraction analysis shows that the mineral (except quartz) content decreases after SC-CO2 treatment, and in particular, the proportions of carbonate minerals significantly decrease by about 12%. The primary pores and fractures are eroded through dissolution, and new pores and fracture structures are developed on the surface microstructure. In addition, the proportion of micropores and mesopores decreases, while the proportion of macropores increases after SC-CO2 treatment. The specific surface area and average pore size present upward trends during SC-CO2 treatment. The changes of mineral assemblage and pore structure lead to the obvious decline of mechanical properties in shale reservoirs. This study contributes to understanding the evolution characteristics of mechanical properties under SC-CO2 treatment, which is of great significance for the efficient exploitation in shale reservoirs.

18.
Materials (Basel) ; 13(7)2020 Apr 01.
Artículo en Inglés | MEDLINE | ID: mdl-32244793

RESUMEN

Vanadate is an important functional material. It has been widely studied and applied in luminescence and photocatalysis. Vanadium compounds have been synthesized to investigate the thermal expansion properties and structure. Both BiVO4 and Co2V2O7 are monoclinic at room temperature, FeVO4's crystal structure is triclinic, and CrVO4 is orthorhombic. The relatively linear, thermal-expansion, and temperature-dependent Raman spectroscopy results showed that the phase transition of BiVO4 occurred at 200 to 300 °C. The coefficient of thermal expansion (CTE) of Co2V2O7 was larger than that of the monoclinic structure BiVO4. The CTE of the tetragonal structure of BiVO4 was 15.27 × 10-6 °C-1 which was the largest CTE in our measurement results, and the CTE of anorthic structure FeVO4 was 2.84 × 10-6 °C-1 and was the smallest.

19.
Environ Sci Pollut Res Int ; 27(26): 33351-33361, 2020 Sep.
Artículo en Inglés | MEDLINE | ID: mdl-32533480

RESUMEN

Water resource shortage has become a major bottleneck restricting the sustainable development of China's economy and society. Identifying the driving factors of water use is helpful to put forward suggestions of water-saving society construction. This paper takes Jiangsu province as example and adopts LMDI (Logarithmic Mean Divisia Index) method to decompose the driving factors of water use change. We find that the production intensity effect and the industrial structure effect are the two dominating factors that induce the decline of total water use. Economic development effect is the most important factor to promote the increase of total water use, and domestic intensity effect is the secondary factors except for 2000-2003 period. Population scale effect on the total water use is relatively weak. The domestic intensity effect is the primary factor to promote the increase of domestic water use; the urbanization effect is a secondary factor to promote the increase of domestic water use. Based on the research conclusions, the corresponding water-saving policy is put forward.


Asunto(s)
Desarrollo Económico , Agua , China , Industrias , Urbanización
20.
Healthcare (Basel) ; 8(2)2020 Apr 30.
Artículo en Inglés | MEDLINE | ID: mdl-32365866

RESUMEN

China's economy in recent decades has developed at a very rapid speed, as evidenced by its GDP jumping to second place in the world. Although utilization of domestic water resources has helped spur economic development, sewage discharge as an undesirable output has unfortunately caused many negative effects on human health, causing concern from all walks of life. Therefore, governments in China at all levels are committed to urban sewage treatment policies in order to reduce the negative impact of water pollution on society. While most existing studies have targeted the macro-level modes of economic development and environmental pollution, their selection of research objects is too narrow by failing to adequately consider China's water pollution and the consequential national health crisis. This study takes cities in 30 provinces of China as the research objects and applies various influencing factors of urban wastewater treatment and health (as two stages) to the modified two-stage dynamic Slacks-Based Measures (SBM) Data Envelopment Analysis (DEA) model. The results reveal that the overall efficiency of each province is increasing and that the efficiency of the wastewater treatment stage is greater, thus contributing to overall efficiency. Conversely, the health stage's efficiency is far lower than the wastewater treatment stage's efficiency, which has a notably adverse effect on overall efficiency. In addition, most input-output variables need much improvement. Based on the findings herein, we offer specific suggestions to each province for improving sewage treatment capacity, the level of medical care, and the quality of national health.

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