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1.
BMC Public Health ; 24(1): 887, 2024 Mar 25.
Artigo em Inglês | MEDLINE | ID: mdl-38523310

RESUMO

OBJECTIVE: With the ongoing evolution of the healthcare system and shifts in cultural paradigms, there is a pressing need to delve into the medical decision-making behaviors of general Chinese public and understand their underlying motivations. This research seeks to elucidate the prevailing tendencies in these decision-making processes and to empirically validate the pivotal factors that shape their choices, offering valuable insights for healthcare policymakers and institutions. METHOD: A comprehensive survey was administered to 2,696 Chinese residents to examine their medical decision-making patterns. These patterns were classified into two primary categories: Unilateral Decision-making (Doctor-dominant, Family-centric, and Patient-driven subtypes) and Collaborative Decision-making (Doctor-led, Doctor-Patient, Patient-Family, and Doctor-Patient-Family subtypes). Binary logistic regression analysis was employed to empirically pinpoint the significant factors influencing these decision-making frameworks. RESULTS: The study's analysis reveals distinct preferences in medical decision-making among Chinese residents. In the Collaborative Decision-making category, chosen by 70.81% of participants, the subtypes are as follows: Doctor-led (29.90%), Doctor-Patient (13.54%), Patient-Family (2.93%), and Doctor-Patient-Family (24.44%). The Unilateral Decision-making, preferred by 29.19%, includes Doctor-dominant (23.22%), Family-centric (1.74%), and Patient-driven (4.23%) models. The preference for Collaborative Decision-making is associated with higher educational levels, specific marital statuses (particularly married but childless), and choices of rural residents' basic medical insurance or occupational basic medical insurance. In contrast, Unilateral Decision-making correlates with males, individuals with religious beliefs, certain occupational roles (like civil servants), and holders of commercial or publicly funded medical insurance. CONCLUSION: This study elucidates the complex interplay of socio-cultural and individual determinants shaping medical decision-making in China. The findings reveal a marked inclination towards collaborative models, closely linked to educational level, marital status, and specific insurance types, reflecting an evolving trend towards participatory healthcare. Simultaneously, the persistence of unilateral models, influenced by gender, religious beliefs, and occupational roles, highlights the heterogeneity within Chinese healthcare preferences. These insights are crucial for policymakers and healthcare practitioners, underscoring the need for adaptable, culturally attuned healthcare frameworks that cater to this diversity, thereby enhancing patient engagement and healthcare efficacy.


Assuntos
Tomada de Decisões , Participação do Paciente , Masculino , Humanos , Modelos Logísticos , China , Escolaridade
2.
New Phytol ; 236(6): 2311-2326, 2022 12.
Artigo em Inglês | MEDLINE | ID: mdl-36114658

RESUMO

The annual planting area of major inbred rice (Oryza sativa) cultivars reach more than half of the total annual planting area of inbred rice cultivars in China. However, how the major inbred rice cultivars changed during decades of genetic improvement and why they can be prevalently cultivated in China remains unclear. Here, we investigated the underlying genetic changes of major inbred cultivars and the contributions of landraces and introduced cultivars during the improvement by resequencing a collection of 439 rice accessions including major inbred cultivars, landraces, and introduced cultivars. The results showed that landraces were the main genetic contribution sources of major inbred Xian (Indica) cultivars, while introduced cultivars were that of major inbred Geng (Japonica) cultivars. Selection scans and haplotype frequency analysis shed light on the reflections of some well-known genes in rice improvement, and breeders had different preferences for the Xian's and Geng's breeding. Six candidate regions associated with agronomic traits were identified by genome-wide association mapping, five of which were under positive selection in rice improvement. Our study provides a comprehensive insight into the development of major inbred rice cultivars and lays the foundation for genomics-based breeding in rice.


Assuntos
Oryza , Oryza/genética , Melhoramento Vegetal/métodos , Estudo de Associação Genômica Ampla , Variação Genética , Genômica , China
3.
J Food Process Preserv ; 41(1): e12847, 2017 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-28239212

RESUMO

This study details the nutritional and digestive properties of protein isolates that are extracted from carp (Cyprinus Carpio L.) muscle using pH shifting methods. Alkaline (ALPI) and acid (ACPI) protein isolates exhibit higher protein yields (87.6%, 76.3%, respectively). In addition to the high recovery of myofibrillar protein, a portion of the water-soluble proteins is also recovered. The moisture contents of ACPI and ALPI are 85.5% and 88.5%, respectively, and the crude protein contents of these two fractions are 83.20% and 83.0%, respectively, both contents of which are higher than those for fresh muscle. Most part of the ash and fat are removed in the separation process. The protein isolation is also found to be lighter and whiter than the fresh muscle and there is no difference between amino acid content of protein isolation and that of fresh muscle. The maximum solubility of water washed surimi is 73.21%, while solubility of ACPI-2 and ALPI-2 (pH 7.0) are 66.67% and 62.08%, respectively. The digestibility of ALPI and ACPI is improved after being treated with chymotrypsin, which is about 7-8 times as that of fresh muscle. The results indicate that the protein isolates have better nutritional and digestive properties than the fresh muscle does in food processing. PRACTICAL APPLICATIONS: Common carp is a lower additional value fish that exists in large amount in China. This study investigates nutritional and digestive properties of protein from carp extracted by pH shifting methods. According to the obtained data in this study, pH shifting method is a good protein recovery method that can effectively remove bone spurs, skin, fat and other impurities. In addition, sarcoplasmic proteins can also be recovered. The nutritional properties of protein isolates of carp were suitable for supplementing as an ingredient for human consumption. The pH-shift process greatly improves the protein digestibility. Therefore, there are broad application prospects of the protein isolation as protein ingredients in food industry.

4.
Sci Rep ; 14(1): 505, 2024 Jan 04.
Artigo em Inglês | MEDLINE | ID: mdl-38177215

RESUMO

Geothermal power generation employing Organic Rankine Cycle (ORC) technology is a widely acknowledged and conventional approach for harnessing geothermal energy. In an innovative advancement, we propose a novel design integrating downhole thermoelectric power generation with a coaxial borehole heat exchanger. This design aims to enhance the efficiency and sustainability of geothermal energy utilization. In this innovative design, the geothermal well is divided into two distinct sections: a power generation section and a heat exchanging section, achieved through the implementation of a packer positioned from the uppermost part of the targeted zone. The process involves the injection of cold fluid downhole via an insulated pipe. Subsequently, a portion of the injected fluid is directed to flow in reverse within the casing-tubing annulus above the packer, while another portion circulates into the casing-tubing annulus below the packer before ascending through the tubing. This dual flow mechanism establishes distinct cold and hot sources for the thermoelectric generator, a key feature facilitated by this innovative design. Analytical models detailing of downhole temperature distribution for thermoelectric power have been meticulously developed. A comprehensive case study, focusing on a geothermal well with 3000 m length of power generation section and 500 m heat exchanging section, has been conducted. The results indicate that a significant generating capacity could be achieved with a higher wellhead temperature, and the payback period under different carbon tax scenarios is about 6-8 year. Furthermore, the effects of injection rate, fluid diversion ratio, and casing-tubing configuration on power performance and thermal-electricity efficiency are also discussed. This method not only enables the concurrent harvesting of geothermal energy and power generation but also operates consistently throughout the year. The results thus emphasize the viability and economic feasibility of the proposed approach.

5.
Women Birth ; 37(5): 101655, 2024 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-39024982

RESUMO

BACKGROUND: Midwives experience elevated levels of work-related stress. However, there is limited understanding of the patterns of this stress, its sociodemographic and work-related determinants, and its association with sub-health. METHOD: This multi-center cross-sectional study, conducted in 21 hospitals in Zhuhai City, Guangdong Province, China, involved 300 midwives. Work-related stress levels in midwives were evaluated using the Chinese version of the Nursing Stress Scale, while social, physical and mental sub-health status was measured with the Sub-Health Measurement Scale. Utilizing latent profile analysis, the study aimed to categorize midwives into homogeneous profiles based on patterns of work-related stress. RESULTS: Among the 300 midwives examined, three distinct profiles were identified: profile 1 (n=57, 19 %), characterized by low work-related stress; profile 2 (n=149, 50 %), representing the moderate work-related stress class; and profile 3 (n=94, 31 %), indicative of high work-related stress. Midwives in the high work-related stress profile tended to be younger, with lower monthly income, lower professional titles, and a higher likelihood of night shift work (all P<0.01). Significant and noteworthy trends were observed in sociodemographic characteristics (age, monthly income, and professional title) and work-related characteristics (night shift status). After controlling for confounders, the work-related stress profile demonstrated a negative association with social, physical and mental sub-health status. CONCLUSION: This study highlights integrating stress domains and adopting a person-centered approach to examine midwives' work-related stress. Identifying predictors of profile membership and their relationship with sub-health can inform tailored interventions to reduce stress and improve midwives' well-being.


Assuntos
Tocologia , Enfermeiros Obstétricos , Estresse Ocupacional , Humanos , Estudos Transversais , Feminino , Adulto , Estresse Ocupacional/psicologia , Tocologia/estatística & dados numéricos , China/epidemiologia , Pessoa de Meia-Idade , Enfermeiros Obstétricos/psicologia , Inquéritos e Questionários , Nível de Saúde , Estresse Psicológico , Local de Trabalho/psicologia
6.
Materials (Basel) ; 17(12)2024 Jun 13.
Artigo em Inglês | MEDLINE | ID: mdl-38930268

RESUMO

Medium-entropy alloys (MEAs) have attracted considerable attention in recent decades due to their exceptional material properties and design flexibility. In this study, lightweight and non-equiatomic MEAs with low density (~5 g/cm3), high strength (yield strength: 1200 MPa), and high ductility (plastic deformation: ≧10%) were explored. We fine-tuned a previously developed Ti-rich MEA by microalloying it with small amounts of Ni (reducing the atomic radius and increasing the elastic modulus) through solid solution strengthening to achieve a series of MEAs with enhanced mechanical properties. Among the prepared MEAs, Ti65Ni1 and Ti65Ni3 exhibited optimal properties in terms of the balance between strength and ductility. Furthermore, the Ti65Ni3 MEA was subjected to thermo-mechanical treatment (TMT) followed by cold rolling 70% (CR70) and cold rolling 85% (CR85). Subsequently, the processed samples were rapidly annealed at 743 °C, 770 °C, 817 °C, and 889 °C at a heating rate of 15 °C/s. X-ray diffraction analysis revealed that the MEA could retain its single-body-centered cubic solid solution structure after TMT. Additionally, the tensile testing results revealed that increasing the annealing temperature led to a decrease in yield strength and an increase in ductility. Notably, the Ti65Ni3 MEA sample that was subjected to CR70 and CR85 processing and annealed for 30 s exhibited high yield strength (>1250 MPa) and ductility (>13%). In particular, the Ti65Ni3 MEA subjected to CR85 exhibited a specific yield strength of 264 MPa·cm3/g, specific tensile strength of 300 MPa·cm3/g, and ductility of >13%.

7.
Front Public Health ; 11: 1087358, 2023.
Artigo em Inglês | MEDLINE | ID: mdl-36908484

RESUMO

Objective: Machine learning (ML) algorithms, as an early branch of artificial intelligence technology, can effectively simulate human behavior by training on data from the training set. Machine learning algorithms were used in this study to predict patient choice tendencies in medical decision-making. Its goal was to help physicians understand patient preferences and to serve as a resource for the development of decision-making schemes in clinical treatment. As a result, physicians and patients can have better conversations at lower expenses, leading to better medical decisions. Method: Patient medical decision-making tendencies were predicted by primary survey data obtained from 248 participants at third-level grade-A hospitals in China. Specifically, 12 predictor variables were set according to the literature review, and four types of outcome variables were set based on the optimization principle of clinical diagnosis and treatment. That is, the patient's medical decision-making tendency, which is classified as treatment effect, treatment cost, treatment side effect, and treatment experience. In conjunction with the study's data characteristics, three ML classification algorithms, decision tree (DT), k-nearest neighbor (KNN), and support vector machine (SVM), were used to predict patients' medical decision-making tendency, and the performance of the three types of algorithms was compared. Results: The accuracy of the DT algorithm for predicting patients' choice tendency in medical decision making is 80% for treatment effect, 60% for treatment cost, 56% for treatment side effects, and 60% for treatment experience, followed by the KNN algorithm at 78%, 66%, 74%, 84%, and the SVM algorithm at 82%, 76%, 80%, 94%. At the same time, the comprehensive evaluation index F1-score of the DT algorithm are 0.80, 0.61, 0.58, 0.60, the KNN algorithm are 0.75, 0.65, 0.71, 0.84, and the SVM algorithm are 0.81, 0.74, 0.73, 0.94. Conclusion: Among the three ML classification algorithms, SVM has the highest accuracy and the best performance. Therefore, the prediction results have certain reference values and guiding significance for physicians to formulate clinical treatment plans. The research results are helpful to promote the development and application of a patient-centered medical decision assistance system, to resolve the conflict of interests between physicians and patients and assist them to realize scientific decision-making.


Assuntos
Inteligência Artificial , Preferência do Paciente , Humanos , Algoritmos , Aprendizado de Máquina , Tomada de Decisão Clínica
8.
Plants (Basel) ; 12(3)2023 Feb 03.
Artigo em Inglês | MEDLINE | ID: mdl-36771759

RESUMO

Grain size and flag leaf angle are two important traits that determining grain yield in rice. However, the mechanisms regulating these two traits remain largely unknown. In this study, a rice long grain 5 (lg5) mutant with a large flag leaf angle was identified, and map-based cloning revealed that a single base substitution followed by a 2 bp insertion in the LOC_Os05g40384 gene resulted in larger grains, a larger flag leaf angle, and higher plant height than the wild type. Sequence analysis revealed that lg5 is a novel allele of elongated uppermost internode-1 (EUI1), which encodes a cytochrome P450 protein. Functional complementation and overexpression tests showed that LG5 can rescue the bigger grain size and larger flag leaf angle in the Xiushui11 (XS) background. Knockdown of the LG5 transcription level by RNA interference resulted in elevated grain size and flag leaf angle in the Nipponbare (NIP) background. Morphological and cellular analyses suggested that LG5 regulated grain size and flag leaf angle by promoting cell expansion and cell proliferation. Our results provided new insight into the functions of EUI1 in rice, especially in regulating grain size and flag leaf angle, indicating a potential target for the improvement of rice breeding.

9.
J Food Sci ; 87(1): 206-215, 2022 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-34967015

RESUMO

The purpose of this study was to reveal the role of mitochondria in indicating a change in the freshness of the adductor muscle of Mizuhopecten yessoensis during cold storage and hardening. The adductor muscle hardens after 96 h of cold storage and reaches the maximum degree of hardening in 6 h. In this study, after hardening (102 h), the muscle fiber structure obviously broke and curled, and the sarcomere structure disappeared at 150 h. After hardening (102 h), the morphology of the mitochondria changed, including swelling, cristea breaking and membrane structure disappearance. The arginine phosphate content decreased gradually from the initial 4.618 to 1.306 µmol/g at 48 h, and there was no further obvious change. The ATP content decreased from 6.02 to 1.07 µmol/g in 120 h. The mitochondrial membrane potential (Δφ) was measured by a fluorescence method (JC-1). The changes in freshness could be divided into three classes according to the Δφ difference between the mitochondria in the adductor muscle after adding ADP and CCCP. Mitochondrial function was complete from 0 to 6 h; mitochondrial function began to decline at 6 to 48 h; and mitochondrial function completely disappeared after 48 h. The results showed that the mitochondrial membrane potential compared with other indicators could more sensitively reflect the changes in freshness during the cold storage hardening process of the adductor muscle. PRACTICAL APPLICATION: It is very important to interprete the post-mortem energy metabolism for controlling the muscle quality of Yesso scallop. The K value which was developed based on ATP-related compounds is widely used in evaluating the freshness of seafood. Mitochondria is the main sites of cellular energy metabolism and the changes of its structure and activity can sensitively reflect the quality changes in muscle cell. It is expected to develop a more sensitive freshness evaluation index.


Assuntos
Pectinidae , Animais , Mitocôndrias , Músculo Esquelético/metabolismo , Alimentos Marinhos/análise
10.
Aging (Albany NY) ; 14(15): 6149-6168, 2022 Aug 05.
Artigo em Inglês | MEDLINE | ID: mdl-35939336

RESUMO

Cancer immunoediting is defined as the integration of the immune system's dual host-protective and tumor-promoting roles, including three phases: elimination, equilibrium, and escape. Immune selective pressure causes tumor cells to lose major histocompatibility complex expression or acquire immunosuppressive gene expression, which promotes tumor immune evasion and tumor progression. Interleukin-17D (IL-17D), a member of the IL-17 family of cytokines, plays an important role in the host defense against infection and inflammation. However, the role of IL-17D in the progression of lung cancer remains unclear. In this study, we found that IL-17D was highly expressed in human lung cancer, and increased IL-17D expression was associated with tumor stage and short overall survival. IL-17D overexpression significantly promoted tumor growth in subcutaneous xenograft mouse models but only slightly affected cell proliferation in vitro. Using flow cytometry, we found that IL-17D overexpression enhances the recruitment of tumor-associated macrophages to the tumor microenvironment. Based on the expression profile of IL17D-overexpressing A549 cells, we found that IL-17D increased the expression levels of macrophage polarization- and recruitment-related genes through the MAPK signaling pathway. Moreover, inhibition of the p38 pathway blocked macrophage infiltration induced by IL-17D. These results suggest that IL-17D regulates the tumor immune microenvironment via the p38 MAPK signaling pathway, highlighting IL-17D as a potential therapeutic target for lung cancer.


Assuntos
Interleucina-17/metabolismo , Interleucina-27 , Neoplasias Pulmonares , Animais , Humanos , Interleucina-27/genética , Neoplasias Pulmonares/patologia , Camundongos , Transdução de Sinais , Microambiente Tumoral , Macrófagos Associados a Tumor , Proteínas Quinases p38 Ativadas por Mitógeno/metabolismo
11.
Front Plant Sci ; 13: 880919, 2022.
Artigo em Inglês | MEDLINE | ID: mdl-35548297

RESUMO

Grain size, grain number per panicle, and grain weight are key agronomic traits that determine grain yield in rice. However, the molecular mechanisms coordinately controlling these traits remain largely unknown. In this study, we identified a major QTL, SMG3, that is responsible for grain size, grain number per panicle, and grain weight in rice, which encodes a MYB-like protein. The SMG3 allele from M494 causes an increase in the number of grains per panicle but produces smaller grain size and thousand grain weight. The SMG3 is constitutively expressed in various organs in rice, and the SMG3 protein is located in the nucleus. Microscopy analysis shows that SMG3 mainly produces long grains by increasing in both cell length and cell number in the length direction, which thus enhances grain weight by promoting cell expansion and cell proliferation. Overexpression of SMG3 in rice produces a phenotype with more grains but reduces grain length and weight. Our results reveal that SMG3 plays an important role in the coordinated regulation of grain size, grain number per panicle, and grain weight, providing a new insight into synergistical modification on the grain appearance quality, grain number per panicle, and grain weight in rice.

12.
BMJ Open ; 11(8): e046745, 2021 08 10.
Artigo em Inglês | MEDLINE | ID: mdl-34376445

RESUMO

OBJECTIVE: Recently, China has experienced a considerable influence of the COVID-19 pandemic on the local people's health and economy. Hence, the current research aims to investigate the psychological and socioeconomic impact of COVID-19 on rural communities in the Sichuan Province of China. METHODS: A total of 499 participants (village representatives of Sichuan Province) were approached to partake in a cross-sectional online survey and share their experience regarding the ongoing pandemic. The descriptive statistics and ordinary least squares (OLS) regression were used to analyse the data. RESULTS: Our analysis revealed that the pandemic has significantly affected local people psychologically, leading to socioeconomic vulnerability. Notably, we find that local households are worried about their income losses regardless of their socioeconomic status (40%-43%), level of income (37%-43%) and industry involvement (38%-43%). However, as income increases, the level of stress decreases. The results further show that government transfer payment is a significant factor in reducing stress due to its reliable and uninterrupted income flow. Contrary to our proposition, the pandemic stress was less observed, which might be because of people's trust in government and effective antiepidemic countermeasures to contain the disease. CONCLUSION: This study finds that COVID-19 has a significant impact on local people's health, psychology and income. This study is one of the first to provide empirical evidence regarding the early health and socioeconomic effects of COVID-19 at the household level in rural communities, which are very important to devise policies to ease the outbreak and prevent further losses at the local community level.


Assuntos
COVID-19 , Pandemias , China/epidemiologia , Estudos Transversais , Humanos , População Rural , SARS-CoV-2 , Inquéritos e Questionários
13.
Front Oncol ; 11: 659131, 2021.
Artigo em Inglês | MEDLINE | ID: mdl-34141615

RESUMO

Tumor immune escape plays a critical role in malignant tumor progression and leads to the failure of anticancer immunotherapy. Spi-B, a lymphocyte lineage-specific Ets transcription factor, participates in mesenchymal invasion and favors metastasis in human lung cancer. However, the mechanism through which Spi-B regulates the tumor immune environment has not been elucidated. In this study, we demonstrated that Spi-B enhanced the infiltration of tumor-associated macrophages (TAMs) in the tumor microenvironment using subcutaneous mouse models and clinical samples of human lung cancer. Spi-B overexpression increased the expression of TAM polarization- and recruitment-related genes, including CCL4. Moreover, deleting CCL4 inhibited the ability of Spi-B promoting macrophage infiltration. These data suggest that Spi-B promotes the recruitment of TAMs to the tumor microenvironment via upregulating CCL4 expression, which contributes to the progression of lung cancer.

14.
Environ Pollut ; 271: 116314, 2021 Feb 15.
Artigo em Inglês | MEDLINE | ID: mdl-33360656

RESUMO

To explore a novel strategy for the remediation of soils polluted with Cu and Cd, three strains of plant-growth-promoting rhizobacteria (PGPRs) isolated from contaminated mines and two grass species (perennial ryegrass and tall fescue) were selected in this study. The performance of PGPR strains in metal adsorption, maintaining promotion traits under stress, and ameliorating phytostabilization potential was evaluated. Cd2+ exerted a stronger deleterious effect on microbial growth than Cu2+, but the opposite occurred for grass seedlings. Adsorption experiment showed that the growing PGPR strains were able to immobilize maximum 79.49% Cu and 81.35% Cd owing to biosorption or bioaccumulation. The strains exhibited the ability to secrete indole-3-acetic acid (IAA) and dissolve phosphorus in the absence and presence of metals, and IAA production was even enhanced in the presence of low Cu2+ (5 mg L-1). However, the siderophore-producing ability of the isolates was strongly suppressed under Cu and Cd exposure. Ryegrass was further selected for pot experiments owing to its higher germination rate and tolerance under Cu and Cd stress than fescue. Pot-experiment results revealed that PGPR addition significantly increased the shoot and root biomasses of ryegrass by 11.49%-44.50% and 43.53%-90.29% in soil co-contaminated with 800 mg Cu kg-1 and 30 mg Cd kg-1, respectively. Metal uptake and translocation in inoculated ryegrass significantly decreased owing to the reduced diethylenetriamine pentaacetic acid-extractable metal content and increased residual metal-fraction percentage mediated by PGPR. Interestingly, stress mitigation was observed in these inoculated plants; in particular, their malondialdehyde content and superoxide dismutase activity were even significantly lower than those of ryegrass under normal conditions. Therefore, PGPR could be a promising option to enhance the phytostabilization efficiency of Cu and Cd in heavily polluted soils.


Assuntos
Lolium , Metais Pesados , Poluentes do Solo , Biodegradação Ambiental , Cádmio , Metais Pesados/análise , Solo , Poluentes do Solo/análise
15.
PLoS One ; 14(8): e0220128, 2019.
Artigo em Inglês | MEDLINE | ID: mdl-31386664

RESUMO

Using abandoned gas wells as geothermal resources for energy production is an effective way to extract geothermal energy from geological formations. These abandoned wells have the potential to significantly contribute in the rising global demand for energy without requiring the land disruption resulting from deep drilling or digging, processes necessary for energy extraction from geological formations via more traditional methods. In this paper, a method to extract geothermal energy from abandoned gas wells is proposed. The method offers an efficient, economical, and environmentally-conscious way to generate electricity. A mathematical model of a thermal and hydraulic coupling process is constructed, and a 3D numerical model is generated to study the process of geothermal energy extraction by retrofitting an abandoned gas reservoir into a geothermal reservoir. Using the model, heat extraction and fluid flow are analyzed over a period of 50 years. The heat production, electricity generation, and thermal recovery over the lifetime of the reservoir indicate that a commercially viable geothermal dual well system can produce geothermal energy effectively. Dual-well systems contain at least one injection well and one production well. They are composed of a two-way flow system in which the fluid flows into the reservoir via an injection well and returns from the production well having absorbed thermal energy from the surrounding rocks. Sensitivity analysis of the main parameters controlling the average outlet temperature of the fluid from the sedimentary geothermal system reveals that abandoned gas wells are a suitable source of geothermal energy. This energy can be harvested via a method whose use of reservoir fluids differs from that of the traditional method of closed-loop circulation via a borehole heat exchanger. Here, it is demonstrated that abandoned oil and gas fields can be repurposed to be geothermal energy sources that provide low-cost electricity and are economically sustainable.


Assuntos
Gases , Energia Geotérmica , Temperatura Alta
16.
Huan Jing Ke Xue ; 36(4): 1141-7, 2015 Apr.
Artigo em Zh | MEDLINE | ID: mdl-26164883

RESUMO

Research on the differences of air quality index (AQI) especially AQI of particulate matters between China and America and analysis of hourly monitored readings from April to December in 2013 released by Environmental Monitoring Station of China indicated that: (1) Although China lagged behind America in formulating and publishing of AQI standards, the AQI standards published in 2012 in China covered more pollutant indexes than before and could objectively reflect the characteristics of air pollution in China, and were more close to the residens's feeling about air quality. (2) The methods adopted for calculation of particulate matter hourly AQI were different in China and America, and the comparison revealed that the calculation method adopted by China using the 24 h average concentration breakpoint of particulate matters to replace the 1 h average concentration breakpoint would enhance the severity of the pollution level. (3) The breakpoint of PM2.5 -24 h in China was less rigorous than that in America when AQI < 200, which led to the inconsistence between the ratio of PM2.5/PM10 and the real situation in China. (4) Analysis on the monitoring readings from station of Beijing Olympic Sports Center showed that when AQI < 50, the ratio of PM2.5/PM10 was less than 0.5 and increased with.the increasing of AQI. Correction and adjustment of particulate matter real-time calculation method and breakpoints of PM2.5 and PM10 were suggested in China.


Assuntos
Poluição do Ar , Monitoramento Ambiental , Poluentes Atmosféricos , China , Material Particulado , Estados Unidos
17.
Huan Jing Ke Xue ; 36(12): 4340-7, 2015 Dec.
Artigo em Zh | MEDLINE | ID: mdl-27011966

RESUMO

In order to evaluate the effects of the implementation of emission reduction measures and the revolution of air quality of Beijing during APEC, the evolution characteristics of air quality was analyzed based on the hourly monitored readings of Olympic Sports Center from 1 to 15 November 2014 released by Environmental Monitoring Station of China, and compared with that in 2013. The results showed that: (1) PM2.5 was the main pollutant in Beijing. The air quality was good during the period of APEC with three obvious pollution events, and it was better than that in the same period in 2013, indicating that the implementation of emission reduction measures had made significant contribution to the improvement of air quality. (2) During the period of APEC, the concentrations of PM2.5 of 5 days were below the World Health Organization (WHO) standard (25 µg · m⁻³), and the concentration of SO2 met the WHO standard during this time. (3) During the period of APEC, the ratio of PM2.5, and PM10 was less than 0.5 when the air quality was good, and gradually increased with the increasing pollution level. The ratio reached 0.9 when the air was seriously polluted. (4) Compared with the same time in 2013, although the implementation of emission reduction measures made contribution to the reduction of the concentration of PM2.5, its contributions to the reduction of SO2 and CO concentration were much more obvious than that of PM2.5, and it had little impact on the reduction of NO2 concentration, and the reduction order of pollutants emission was SO2 > CO > PM > NO2, indicating that the sources, effects and emission reduction of PM2.5 were complex, and further studies are required.


Assuntos
Poluentes Atmosféricos/análise , Material Particulado/análise , Pequim , Monitoramento Ambiental
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