BACKGROUND In recent years,approximately half of the newly diagnosed cases and mortalities attributed to hepatocellular carcinoma(HCC)have been reported in China.Despite the high incidence of HCC,there remains a pauci...BACKGROUND In recent years,approximately half of the newly diagnosed cases and mortalities attributed to hepatocellular carcinoma(HCC)have been reported in China.Despite the high incidence of HCC,there remains a paucity of data regarding the natural growth pattern and the determination of optimal surveillance intervals specific to the Chinese population.AIM To quantify the natural tumor growth pattern of HCC in regional China.METHODS A retrospective analysis was performed on patients from a single institution in Southwest China who had undergone two or more serial dynamic computed tomography or magnetic resonance imaging scans between 2014 and 2020,without having received any anti-cancer therapy.Tumor growth was assessed using tumor volume doubling time(TVDT)and tumor growth rate(TGR),with volumes measured manually by experienced radiologists.Simple univariate linear regression and descriptive analysis were applied to explore associations between growth rates and clinical factors.RESULTS This study identifies the median TVDT for HCC as 163.4 d,interquartile range(IQR)72.1 to 302.3 d,with a daily TGR of 0.42%(IQR 0.206%-0.97%).HCC growth patterns reveal that about one-third of tumors grow indolently with TVDT exceeding 270 d,another one-third of tumors exhibit rapid growth with TVDT under 90 d,and the remaining tumors show intermediate growth rates,with TVDT ranging between 3 to 9 months.CONCLUSION The identified TGRs support biannual surveillance and follow-up for HCC patients in certain regions of China.Given the observed heterogeneity in HCC growth,further investigation is warranted.展开更多
Semi-empirical method PM3 was used to study the geometry and vibrational spectrum of N-(2-hydroxy-l-naphthyl-methylene)-l-pyrenamine (NPY) with the intermediate hydrogen bond. Results are comparable to experimentation...Semi-empirical method PM3 was used to study the geometry and vibrational spectrum of N-(2-hydroxy-l-naphthyl-methylene)-l-pyrenamine (NPY) with the intermediate hydrogen bond. Results are comparable to experimentations. Based on results of both NPY and its model, N-(2-hydroxy-l-naphthyl-methylene)aniline, it was found that the N-(2-hydroxy-l-naphthyl-methylene) group is principally responsible for the special hydrogen bonding through conjugation effect.展开更多
The incredible extent of current environmental destruction justifies the modern concern to resist the alienated view of nature as a resource to exploit a totality of dead and meaningless objects, a totally disenchante...The incredible extent of current environmental destruction justifies the modern concern to resist the alienated view of nature as a resource to exploit a totality of dead and meaningless objects, a totally disenchanted world. In this spirit, modern philosophy tries to take nature seriously by recapturing a sense of nature's intrinsic value. Hegel respects nature to the extent that it bears the trace of the human mind, to the extent that it is forced "to speak the voice of reason." Although there are grounds for being critical of the Hegelian project, especially because Hegel remains silent on the issue of our duties towards nature for the sake of nature and his argumentation serves the primordial desires of human reasoning and not the rights of nature itself, it is suggested that no matter how much inauthentic and incomplete is the recognition that the human mind acquires in its dialectical confrontations with nature. Hegelian phenomenology grants the human mind with a remarkable degree of self-certainty, necessary for all its subsequent educational enterprises.展开更多
Cavitating jet is a promising drilling rate improvement technology in both the marine natural gas hydrate (NGH) fluidization exploitation method and the integrated radial jet drilling and completion method. In present...Cavitating jet is a promising drilling rate improvement technology in both the marine natural gas hydrate (NGH) fluidization exploitation method and the integrated radial jet drilling and completion method. In present study, we aim to improve the efficiency of jet erosion and extracting NGH. With a computational fluid dynamics (CFD) method, the pressure, velocity and cavitation field characteristics of organ-pipe cavitating jet (OPCJ) are analysed. The divergent angle, throat length, and divergent length of OPCJ nozzle are preferred to obtain stronger jet cavitation erosion effect. Laboratory experiments of gas hydrate-bearing sediments (GHBS) erosion by OPCJ and conical jet (CJ) are conducted to compare and validate the jet erosion performance. The impinging models of OPCJ and CJ are constructed to study the impact characteristics. Results show that the preferred values of divergent angle, throat length, and divergent length are 15°, 1d, and 3d, respectively, in present simulation conditions. For GHBS, the OPCJ possesses the advantages of high efficiency and low energy consumption. Moreover, the OPCJ has higher penetration efficiency, while showing equivalent penetration ability compared to CJ. During the impinging process, the OPCJ can induce stronger impact pressure and turbulence effect, and also shows stronger chambering effect and bottom cleaning ability compared to CJ. This study presents the erosion performance of OPCJ and CJ on GHBS, and provides preliminary insights on the potential field applications in NGH exploitation.展开更多
A numerical approach to heat and mass transfer in a large water reservoir is presented. This water reservoir is likened to a parallelepiped reservoir whose vertical and lower walls are adiabatic and impermeable. The e...A numerical approach to heat and mass transfer in a large water reservoir is presented. This water reservoir is likened to a parallelepiped reservoir whose vertical and lower walls are adiabatic and impermeable. The equations that govern natural convection in water are solved by the finite volume method and Thomas’salgorithm. The adequacy between the velocity and pressure fields is ensured by the SIMPLE algorithm. We are going to evaluate the water losses by evaporation from three dams in the Nakanbé basin in Burkina Faso for a period of thirty years, that is to say from January 1, 1991, to March 15, 2020. The three dams have a rate of evaporation greater than 40% of the volume of water stored. Indeed the rate of evaporation in each dam increases with the water filling rate in the reservoir: we have observed the following results for each dam in the Nakanbé basin;for the date of 02/27/1988 to 03/13/2020., the Loumbila dam received a total volume of stored water of 22.02 Mm<sup>3</sup> and 10.57 Mm<sup>3</sup> as the total volume of water evaporated at the same date. At the Ouaga dam (2 + 3), it stored a water volume of 4.06 Mm<sup>3</sup> and evaporated 2.03 Mm<sup>3</sup> of its storage volume from 01/01/1988 to 05/07/2016. Finally, with regard to the Bagré dam, it stored 745.16 Mm<sup>3</sup> of water and 365.13 Mm<sup>3</sup> as the volume of water evaporated from 01/01/1993 to 03/31/2020.展开更多
Based on the ancient Chinese doctrine of "less is gain,more is confusion",and Ludwig Mies van der Rohe's architectural concept "less is more",connotations of "less is more" in the con...Based on the ancient Chinese doctrine of "less is gain,more is confusion",and Ludwig Mies van der Rohe's architectural concept "less is more",connotations of "less is more" in the conservation-minded gardens were analyzed from the perspective of design and culture.Taking Tanghe Park in Qinhuangdao City,Landschaftspark Duisburg-Nord,Lingering Garden in Suzhou and Jiangyangpan Eco-park for example,this study stressed the creation of maximum urbanization effects and the most vivid urban landscapes via the least materials,investment,design and human interventions,and analyzed the application of "less is more" in conservationminded garden design.展开更多
Thoreau's Walden and Chinese Tang Poems both attach great importance to nature,devoting large paragraphs to the depiction of it.The significance of this phenomenon is discussed in this paper.Based on the method of...Thoreau's Walden and Chinese Tang Poems both attach great importance to nature,devoting large paragraphs to the depiction of it.The significance of this phenomenon is discussed in this paper.Based on the method of close reading and comparative study,it is found that nature,portrayed by Thoreau and Tang poets share one important character,that is,nature assumes subjectivity as an individual being.展开更多
Purposes:This study uses the method of qualitative research to conduct in-depth interviews with pregnant women,explore the experiences of pregnant women undertake mindfulness training.Methods:The study adopts a qualit...Purposes:This study uses the method of qualitative research to conduct in-depth interviews with pregnant women,explore the experiences of pregnant women undertake mindfulness training.Methods:The study adopts a qualitative,in-depth interview method.Semi-structured interviews were conducted with 10 pregnant women.Data from semi-structured interviews were analysed by qualitative content analysis using QSR NVivo 12 software.Results:Four themes were generated to show how pregnant women experiences of the mindfulness training.They are Emotion management,Benefits of mindfulness training for childbirth,Challenges and influencing factors of mindfulness training and Different attitudes toward mindfulness training.Conclusions:Pregnant women undertaking mindfulness training can effectively reduce stress and has positive effects on work and life.Mindfulness training can be used as a way to improve the mental health of pregnant women.展开更多
The hydrogenation of CO to synthetic natural gas (SNG) needs a high molar ratio of H2/CO (usually large than 3.0 in industry), which consumes a large abundant of hydrogen. The reverse dry reforming reaction (RDR, 2H2 ...The hydrogenation of CO to synthetic natural gas (SNG) needs a high molar ratio of H2/CO (usually large than 3.0 in industry), which consumes a large abundant of hydrogen. The reverse dry reforming reaction (RDR, 2H2 + 2CO←→CH4 + CO2), combining CO methanation with water-gas-shift reaction, can significantly decrease the H2/CO molar ratio to 1 for SNG production. A detailed thermodynamic analysis of RDR reaction was carried out based on the Gibbs free energy minimization method. The effect of temperature, pressure. H2/CO ratio and the addition of H2O, CH4, CO2, O2 and C2H4 into the feed gas on CO conversion, CH4 and CO2 selectivity, as well as CH4 and carbon yield, are discussed. Experimental results obtained on homemade impregnated Ni/Al2O3 catalyst are compared with the calculations. The results demonstrate that low temperature (200-500 °C), high pressure (1-5 MPa) and high H2/CO ratio (at least 1) promote CO conversion and CH4 selectivity and decrease carbon yield. Steam and CO2 in the feed gas decrease the CH4 selectivity and carb on yield, and enhance the CO2 con tent. Extra CH4 elevates the CH4 content in the products, but leads to more carbon formation at high temperatures. O2 significantly decreases the CH4 selectivity and C2H4 results in the generation of carbon.展开更多
In the present work,the conventional natural gas dehydration method(CDM)and stripping gas method(SGM)are technically and economically analyzed,utilizing Aspen HYSYS and Aspen Process Economic Analyzer(APEA),respective...In the present work,the conventional natural gas dehydration method(CDM)and stripping gas method(SGM)are technically and economically analyzed,utilizing Aspen HYSYS and Aspen Process Economic Analyzer(APEA),respectively.To optimize the CDM and SGM,the sensitivities of the water content of dry gas,reboiler duty and raw material loss are analyzed against solvent rate and stripping gas rate.The optimized processes are set to achieve a targeted value of water content in dry gas and analyzed at optimized point.The analysis shows that SGM gives 46%lower TEG feed rate,42%lower reboiler duty and 99.97%pure regenerated TEG.Moreover,economic analysis reveals that SGM has 38%lower annual operating cost compared to CDM.According to results,from both technical and economic point of view,SGM is more feasible for natural gas dehydration compared to CDM.展开更多
Kunming,a city in southwest China,has a climate that is different from most of the other places in the world because of its unique geographical characteristics.Due to its temperate climate,most of the residential buil...Kunming,a city in southwest China,has a climate that is different from most of the other places in the world because of its unique geographical characteristics.Due to its temperate climate,most of the residential buildings in this region are naturally ventilated.Accordingly,a winter thermal comfort study was conducted in Kunming to reveal the thermal response of residents.Indoor and outdoor environmental parameters were measured,and participants were investigated about their clothing,thermal sensations,thermal preferences,and thermal acceptance using online questionnaires.Data from 162 valid questionnaires were collected in the survey.Although the climate is referred to as“mild”,the survey showed that the indoor temperature during winter was lower than the typical comfort range.Nevertheless,the participants responded that most of them felt neutral and comfortable.The neutral temperature of participants living in Kunming was determined to be 16.96℃.The acceptable thermal sensation vote(TSV)range of the residents is-0.72 to 1.52.The acceptable indoor air temperature range is 15.03℃ to 19.55℃,and the optimum indoor air temperature is 17.2℃.According to this study,the existing thermal comfort evaluation models can hardly predict residents’thermal responses in Kunming well.展开更多
Interaction between mothers and midwives during natural childbirth is one of the important factors in relationship between mothers and midwives in natural childbirth. In this qualitative study we explored experiences ...Interaction between mothers and midwives during natural childbirth is one of the important factors in relationship between mothers and midwives in natural childbirth. In this qualitative study we explored experiences of mothers and midwives in interaction with each other in natural childbirth. This study was a part of a larger study which was carried out in Iran in 2013-2014. A total of 23 participants participated in this study. 12 primiparous and multiparous women planned to have natural deliveries and 11 midwives were purposefully included for semi-structured in-depth interviews in this study. For analysis and interpretation of mothers’ and midwives’ experience, conventional content analysis was used. Data were coded in MAXqda software (version 2). Interaction between mothers and midwives could be organized and categorized in one theme “relationship”. This theme consists of two subthemes: “respect for the mother” and “interaction” and five categories: “Feeling confidence, Feeling satisfaction, Associated with sensory relationship, Understanding mother’s situation, Understanding the meaning of interaction”. Good relationship between mothers and midwives in natural childbirth could improve the experience of natural childbirth for mothers. This experience could increase woman’s tendency toward natural birth instead of cesarean section in future pregnancies. Findings of this study can be seen as a challenge for health care professionals and policy makers to upgrade care of natural childbirth based on women’s preferences and needs.展开更多
Concentrating solar thermal power system can provide low carbon,renewable energy resources in countries or regions with strong solar irradiation.For this kind of power plant which is likely to be located in the arid a...Concentrating solar thermal power system can provide low carbon,renewable energy resources in countries or regions with strong solar irradiation.For this kind of power plant which is likely to be located in the arid area,natural draft dry cooling tower is a promising choice.To develop the experimental studies on small cooling tower,a 20 m high natural draft dry cooling tower with fully instrumented measurement system was established by the Queensland Geothermal Energy Centre of Excellence.The performance of this cooling tower was measured with the constant heat input of 600 kW and 840 kW and with ambient temperature ranging from 20 ℃ to 32 ℃.The cooling tower numerical model was refined and validated with the experimental data.The model of 1 MW concentrating solar thermal supercritical CO2 power cycle was developed and integrated with the cooling tower model.The influences of changing ambient temperature and the performance of the cooling tower on efficiency of the power system were simulated.The differences of the mechanism of the ambient temperature effect on Rankine cycle and supercritical CO2 Brayton cycle were analysed and discussed.展开更多
Nanofluids are considered to offer important advantages over conventional heat transfer fluids. A model is developed to analyze the behavior of nanofluids taking into account the solid fraction χ. The Navier-Stokes e...Nanofluids are considered to offer important advantages over conventional heat transfer fluids. A model is developed to analyze the behavior of nanofluids taking into account the solid fraction χ. The Navier-Stokes equations are solved numerically with Alternating Direct Implicit method (ADI method) for various Grashof numbers 104 and 105;we have an excellent agreement between our numerical code and previously published works. Copper-Water nanofluid is used with Pr = 6.2 and solid volume fraction χ is varied as 0%;5%;10%;15% and 20%. The problem considered is a two-dimensional heat transfer in a square cavity. The vertical walls are differentially heated, the left is maintained at hot con- dition (sinusoidal) when the right one is cold. The horizontal walls are assumed to be insulated, non conducting and impermeable to mass transfer. The nanofluid in the enclosure is Newtonian, incompressible and laminar. The nanopar- ticles are assumed to have a uniform shape and size. Moreover, it is assumed that both the fluid phase and nanoparticles are in thermal equilibrium state and they flow at the same velocity. The thermophysical properties of the nanofluid are assumed to be constant except for the density variation in the buoyancy force, which is based on the Boussinesq approximation. Different correlations are proposed for predicting heat transfer for uniform and sinusoidal boundary thermal conditions.展开更多
The equilibrium geometries,excitation energies,force constants and vibrational frequencies for the low-ly- ing electronic states X ~2B_1,~2A_1,~2B_2 and ~2A_2 of the AsH_2 radical have been calculated at the MRSDCI le...The equilibrium geometries,excitation energies,force constants and vibrational frequencies for the low-ly- ing electronic states X ~2B_1,~2A_1,~2B_2 and ~2A_2 of the AsH_2 radical have been calculated at the MRSDCI level with a 3-21G~* basis set.Our calculated geometries,excitation enegies and vibional frequencies for the X ~2B_1 and ~2A_1 states are in good agreement with available experimental data.The electronic transition dipole mo- ments,oscillator strengths for the ~2A_1→X ~2B_1 and ~2A_2→X ~2B_1 transitions,radiative lifetimes for the ~2A_1 and ~2A_2 states are calculated based on the MRSDC^1 wavefunctions,predicting results in reasonable agreement with available experiment.展开更多
Background: Dyspepsia and heartburn are among the most frequent complaints of the upper gastrointestinal tract impacting quality of life. The present study aimed to investigate the impact of drinking a natural mineral...Background: Dyspepsia and heartburn are among the most frequent complaints of the upper gastrointestinal tract impacting quality of life. The present study aimed to investigate the impact of drinking a natural mineral water (medicinal product category “Heilwasser” in Germany) high in hydrogen carbonate (Staatl. Fachingen STILL) on functional dyspeptic complaints and heartburn. Methods: 56 men and women with self-reported heartburn were enrolled to this one-arm pilot study. They had to drink 1.5 L of a hydrogen carbonate rich mineral water each day over a course of six weeks. Participants reported the number and duration of heartburn episodes in a daily dairy. The Reflux Disease Questionnaire (RDQ), Quality of Life in Reflux and Dyspepsia questionnaire (QOLRAD) and the Gastrointestinal Quality of Life Index (GILQI) were used to assess the therapeutic course of the treatment and the Short Form Health Survey (SF-12) to assess general quality of life. Mean ± standard deviation were calculated and pre- and post-treatment changes were compared using the Wilcoxon test. Results: The consumption of a hydrogen carbonate rich mineral water decreased the number of heartburn episodes per week significantly by 4.8 ± 8.2 at the end of the study (p < 0.001). The duration of episodes was also significantly reduced by 25.7 minutes after six weeks of intervention (p < 0.001). Accordingly, the subjectively perceived severity of heartburn, regurgitation and dyspeptic complaints as well as the GERD dimension as assessed by Reflux Disease Questionnaire improved significantly. There was a significant improvement in the disease-specific quality of life as measured by the Gastrointestinal Quality of Life Index (p < 0.001) and by the Quality Of Life in Reflux and Dyspepsia (p < 0.001) questionnaires and the general health-related quality of life as assessed by SF-12 (p < 0.007). Conclusions: The present pilot study provides evidence that supplementation with natural mineral water rich in hydrogen carbonate may improve heartburn and dyspeptic symptoms, which finally resulted in an improvement of the subjectively perceived quality of life. Drinking mineral water rich in hydrogen carbonate may be an alternative remedy for the treatment of dyspeptic symptoms and heartburn. Trial Registration: Eudra CT No 2013-001256-36.展开更多
LIRR's Priject of "Research on Spalling Mechanism Due to Rapid Heating-up of Dense Refractory Castables" declared by Wang Zhanmin,vice-president of LIRR,will gain the fund support from National Natural Science Foun...LIRR's Priject of "Research on Spalling Mechanism Due to Rapid Heating-up of Dense Refractory Castables" declared by Wang Zhanmin,vice-president of LIRR,will gain the fund support from National Natural Science Foundation of China in 2011.展开更多
In modern times,under the dual crisis of nationality and culture,Zhang Junmai returned to the internal philosophy of“Inner Sage,”whereby he started the global exploration of“Outer King”and constructed his own cate...In modern times,under the dual crisis of nationality and culture,Zhang Junmai returned to the internal philosophy of“Inner Sage,”whereby he started the global exploration of“Outer King”and constructed his own categorized Neo-Confucianism thoughts based on the contents of Yangming’s philosophy of mind as well as western philosophies.Therefore,by probing into the foundation of Zhang Junmai’s philosophy of mind,this paper explores the educational significance of the view of life based on honesty,the methodology of giving equal importance to learning and doing,and the world’s point of view contained in it,which may serve as a certain reference for the current education development.展开更多
Based on the contents and temperament of pastoral poetries written by TAO Yuan-ming,by centering on respecting the nature,indifference and optimism,and plainness and authenticity,the paper had analyzed aesthetic ideol...Based on the contents and temperament of pastoral poetries written by TAO Yuan-ming,by centering on respecting the nature,indifference and optimism,and plainness and authenticity,the paper had analyzed aesthetic ideologies contained in his poetries.On this basis,it had discussed the influence of aesthetic ideology of TAO Yuan-ming on the style of classical gardens in South China,which were quiet and natural,elegant and fresh,simple and plain,and far-reaching in artistic conception.By combining with cases,it pointed out that the poetic prose had been directly quoted as the names of gardens or scenic spots of classical gardens in South China,and showed that the aesthetic ideology of TAO Yuan-ming had set up a successful ideal model for cultural landscapes,producing far-reaching influence on the aesthetic state of mind of gardeners or owners of gardens,further instilling humanistic spirit into classical gardens in South China.展开更多
基金Supported by Cultivate Project for the National Natural Science Foundation of China,No.gyfynsfc[2020]-27and National Natural Science Foundation of China,No.81960328.
文摘BACKGROUND In recent years,approximately half of the newly diagnosed cases and mortalities attributed to hepatocellular carcinoma(HCC)have been reported in China.Despite the high incidence of HCC,there remains a paucity of data regarding the natural growth pattern and the determination of optimal surveillance intervals specific to the Chinese population.AIM To quantify the natural tumor growth pattern of HCC in regional China.METHODS A retrospective analysis was performed on patients from a single institution in Southwest China who had undergone two or more serial dynamic computed tomography or magnetic resonance imaging scans between 2014 and 2020,without having received any anti-cancer therapy.Tumor growth was assessed using tumor volume doubling time(TVDT)and tumor growth rate(TGR),with volumes measured manually by experienced radiologists.Simple univariate linear regression and descriptive analysis were applied to explore associations between growth rates and clinical factors.RESULTS This study identifies the median TVDT for HCC as 163.4 d,interquartile range(IQR)72.1 to 302.3 d,with a daily TGR of 0.42%(IQR 0.206%-0.97%).HCC growth patterns reveal that about one-third of tumors grow indolently with TVDT exceeding 270 d,another one-third of tumors exhibit rapid growth with TVDT under 90 d,and the remaining tumors show intermediate growth rates,with TVDT ranging between 3 to 9 months.CONCLUSION The identified TGRs support biannual surveillance and follow-up for HCC patients in certain regions of China.Given the observed heterogeneity in HCC growth,further investigation is warranted.
文摘Semi-empirical method PM3 was used to study the geometry and vibrational spectrum of N-(2-hydroxy-l-naphthyl-methylene)-l-pyrenamine (NPY) with the intermediate hydrogen bond. Results are comparable to experimentations. Based on results of both NPY and its model, N-(2-hydroxy-l-naphthyl-methylene)aniline, it was found that the N-(2-hydroxy-l-naphthyl-methylene) group is principally responsible for the special hydrogen bonding through conjugation effect.
文摘The incredible extent of current environmental destruction justifies the modern concern to resist the alienated view of nature as a resource to exploit a totality of dead and meaningless objects, a totally disenchanted world. In this spirit, modern philosophy tries to take nature seriously by recapturing a sense of nature's intrinsic value. Hegel respects nature to the extent that it bears the trace of the human mind, to the extent that it is forced "to speak the voice of reason." Although there are grounds for being critical of the Hegelian project, especially because Hegel remains silent on the issue of our duties towards nature for the sake of nature and his argumentation serves the primordial desires of human reasoning and not the rights of nature itself, it is suggested that no matter how much inauthentic and incomplete is the recognition that the human mind acquires in its dialectical confrontations with nature. Hegelian phenomenology grants the human mind with a remarkable degree of self-certainty, necessary for all its subsequent educational enterprises.
基金financially supported by National Natural Science Foundation of China(No.52174009 and No.51827804)Marine Economy Development Foundation of Guangdong Province(GDNRC[2022]44)“Technical Support for Stimulation and Testing of Gas Hydrate Reservoirs”.
文摘Cavitating jet is a promising drilling rate improvement technology in both the marine natural gas hydrate (NGH) fluidization exploitation method and the integrated radial jet drilling and completion method. In present study, we aim to improve the efficiency of jet erosion and extracting NGH. With a computational fluid dynamics (CFD) method, the pressure, velocity and cavitation field characteristics of organ-pipe cavitating jet (OPCJ) are analysed. The divergent angle, throat length, and divergent length of OPCJ nozzle are preferred to obtain stronger jet cavitation erosion effect. Laboratory experiments of gas hydrate-bearing sediments (GHBS) erosion by OPCJ and conical jet (CJ) are conducted to compare and validate the jet erosion performance. The impinging models of OPCJ and CJ are constructed to study the impact characteristics. Results show that the preferred values of divergent angle, throat length, and divergent length are 15°, 1d, and 3d, respectively, in present simulation conditions. For GHBS, the OPCJ possesses the advantages of high efficiency and low energy consumption. Moreover, the OPCJ has higher penetration efficiency, while showing equivalent penetration ability compared to CJ. During the impinging process, the OPCJ can induce stronger impact pressure and turbulence effect, and also shows stronger chambering effect and bottom cleaning ability compared to CJ. This study presents the erosion performance of OPCJ and CJ on GHBS, and provides preliminary insights on the potential field applications in NGH exploitation.
文摘A numerical approach to heat and mass transfer in a large water reservoir is presented. This water reservoir is likened to a parallelepiped reservoir whose vertical and lower walls are adiabatic and impermeable. The equations that govern natural convection in water are solved by the finite volume method and Thomas’salgorithm. The adequacy between the velocity and pressure fields is ensured by the SIMPLE algorithm. We are going to evaluate the water losses by evaporation from three dams in the Nakanbé basin in Burkina Faso for a period of thirty years, that is to say from January 1, 1991, to March 15, 2020. The three dams have a rate of evaporation greater than 40% of the volume of water stored. Indeed the rate of evaporation in each dam increases with the water filling rate in the reservoir: we have observed the following results for each dam in the Nakanbé basin;for the date of 02/27/1988 to 03/13/2020., the Loumbila dam received a total volume of stored water of 22.02 Mm<sup>3</sup> and 10.57 Mm<sup>3</sup> as the total volume of water evaporated at the same date. At the Ouaga dam (2 + 3), it stored a water volume of 4.06 Mm<sup>3</sup> and evaporated 2.03 Mm<sup>3</sup> of its storage volume from 01/01/1988 to 05/07/2016. Finally, with regard to the Bagré dam, it stored 745.16 Mm<sup>3</sup> of water and 365.13 Mm<sup>3</sup> as the volume of water evaporated from 01/01/1993 to 03/31/2020.
文摘Based on the ancient Chinese doctrine of "less is gain,more is confusion",and Ludwig Mies van der Rohe's architectural concept "less is more",connotations of "less is more" in the conservation-minded gardens were analyzed from the perspective of design and culture.Taking Tanghe Park in Qinhuangdao City,Landschaftspark Duisburg-Nord,Lingering Garden in Suzhou and Jiangyangpan Eco-park for example,this study stressed the creation of maximum urbanization effects and the most vivid urban landscapes via the least materials,investment,design and human interventions,and analyzed the application of "less is more" in conservationminded garden design.
文摘Thoreau's Walden and Chinese Tang Poems both attach great importance to nature,devoting large paragraphs to the depiction of it.The significance of this phenomenon is discussed in this paper.Based on the method of close reading and comparative study,it is found that nature,portrayed by Thoreau and Tang poets share one important character,that is,nature assumes subjectivity as an individual being.
基金This work is supported by CAMS Innovation Fund for Medical Sciences(CIFMS)(2021-I2M-1-023).
文摘Purposes:This study uses the method of qualitative research to conduct in-depth interviews with pregnant women,explore the experiences of pregnant women undertake mindfulness training.Methods:The study adopts a qualitative,in-depth interview method.Semi-structured interviews were conducted with 10 pregnant women.Data from semi-structured interviews were analysed by qualitative content analysis using QSR NVivo 12 software.Results:Four themes were generated to show how pregnant women experiences of the mindfulness training.They are Emotion management,Benefits of mindfulness training for childbirth,Challenges and influencing factors of mindfulness training and Different attitudes toward mindfulness training.Conclusions:Pregnant women undertaking mindfulness training can effectively reduce stress and has positive effects on work and life.Mindfulness training can be used as a way to improve the mental health of pregnant women.
文摘The hydrogenation of CO to synthetic natural gas (SNG) needs a high molar ratio of H2/CO (usually large than 3.0 in industry), which consumes a large abundant of hydrogen. The reverse dry reforming reaction (RDR, 2H2 + 2CO←→CH4 + CO2), combining CO methanation with water-gas-shift reaction, can significantly decrease the H2/CO molar ratio to 1 for SNG production. A detailed thermodynamic analysis of RDR reaction was carried out based on the Gibbs free energy minimization method. The effect of temperature, pressure. H2/CO ratio and the addition of H2O, CH4, CO2, O2 and C2H4 into the feed gas on CO conversion, CH4 and CO2 selectivity, as well as CH4 and carbon yield, are discussed. Experimental results obtained on homemade impregnated Ni/Al2O3 catalyst are compared with the calculations. The results demonstrate that low temperature (200-500 °C), high pressure (1-5 MPa) and high H2/CO ratio (at least 1) promote CO conversion and CH4 selectivity and decrease carbon yield. Steam and CO2 in the feed gas decrease the CH4 selectivity and carb on yield, and enhance the CO2 con tent. Extra CH4 elevates the CH4 content in the products, but leads to more carbon formation at high temperatures. O2 significantly decreases the CH4 selectivity and C2H4 results in the generation of carbon.
基金financially supported by the National Research and Development Program of China(2017YFC0210900)the National Natural Science Foundation of China(21978011)。
文摘In the present work,the conventional natural gas dehydration method(CDM)and stripping gas method(SGM)are technically and economically analyzed,utilizing Aspen HYSYS and Aspen Process Economic Analyzer(APEA),respectively.To optimize the CDM and SGM,the sensitivities of the water content of dry gas,reboiler duty and raw material loss are analyzed against solvent rate and stripping gas rate.The optimized processes are set to achieve a targeted value of water content in dry gas and analyzed at optimized point.The analysis shows that SGM gives 46%lower TEG feed rate,42%lower reboiler duty and 99.97%pure regenerated TEG.Moreover,economic analysis reveals that SGM has 38%lower annual operating cost compared to CDM.According to results,from both technical and economic point of view,SGM is more feasible for natural gas dehydration compared to CDM.
基金Project(2018YFC0704500)supported by the National Key R&D Program of ChinaProjects(51838007,52130803)supported by the National Natural Science Foundation of China。
文摘Kunming,a city in southwest China,has a climate that is different from most of the other places in the world because of its unique geographical characteristics.Due to its temperate climate,most of the residential buildings in this region are naturally ventilated.Accordingly,a winter thermal comfort study was conducted in Kunming to reveal the thermal response of residents.Indoor and outdoor environmental parameters were measured,and participants were investigated about their clothing,thermal sensations,thermal preferences,and thermal acceptance using online questionnaires.Data from 162 valid questionnaires were collected in the survey.Although the climate is referred to as“mild”,the survey showed that the indoor temperature during winter was lower than the typical comfort range.Nevertheless,the participants responded that most of them felt neutral and comfortable.The neutral temperature of participants living in Kunming was determined to be 16.96℃.The acceptable thermal sensation vote(TSV)range of the residents is-0.72 to 1.52.The acceptable indoor air temperature range is 15.03℃ to 19.55℃,and the optimum indoor air temperature is 17.2℃.According to this study,the existing thermal comfort evaluation models can hardly predict residents’thermal responses in Kunming well.
文摘Interaction between mothers and midwives during natural childbirth is one of the important factors in relationship between mothers and midwives in natural childbirth. In this qualitative study we explored experiences of mothers and midwives in interaction with each other in natural childbirth. This study was a part of a larger study which was carried out in Iran in 2013-2014. A total of 23 participants participated in this study. 12 primiparous and multiparous women planned to have natural deliveries and 11 midwives were purposefully included for semi-structured in-depth interviews in this study. For analysis and interpretation of mothers’ and midwives’ experience, conventional content analysis was used. Data were coded in MAXqda software (version 2). Interaction between mothers and midwives could be organized and categorized in one theme “relationship”. This theme consists of two subthemes: “respect for the mother” and “interaction” and five categories: “Feeling confidence, Feeling satisfaction, Associated with sensory relationship, Understanding mother’s situation, Understanding the meaning of interaction”. Good relationship between mothers and midwives in natural childbirth could improve the experience of natural childbirth for mothers. This experience could increase woman’s tendency toward natural birth instead of cesarean section in future pregnancies. Findings of this study can be seen as a challenge for health care professionals and policy makers to upgrade care of natural childbirth based on women’s preferences and needs.
文摘Concentrating solar thermal power system can provide low carbon,renewable energy resources in countries or regions with strong solar irradiation.For this kind of power plant which is likely to be located in the arid area,natural draft dry cooling tower is a promising choice.To develop the experimental studies on small cooling tower,a 20 m high natural draft dry cooling tower with fully instrumented measurement system was established by the Queensland Geothermal Energy Centre of Excellence.The performance of this cooling tower was measured with the constant heat input of 600 kW and 840 kW and with ambient temperature ranging from 20 ℃ to 32 ℃.The cooling tower numerical model was refined and validated with the experimental data.The model of 1 MW concentrating solar thermal supercritical CO2 power cycle was developed and integrated with the cooling tower model.The influences of changing ambient temperature and the performance of the cooling tower on efficiency of the power system were simulated.The differences of the mechanism of the ambient temperature effect on Rankine cycle and supercritical CO2 Brayton cycle were analysed and discussed.
文摘Nanofluids are considered to offer important advantages over conventional heat transfer fluids. A model is developed to analyze the behavior of nanofluids taking into account the solid fraction χ. The Navier-Stokes equations are solved numerically with Alternating Direct Implicit method (ADI method) for various Grashof numbers 104 and 105;we have an excellent agreement between our numerical code and previously published works. Copper-Water nanofluid is used with Pr = 6.2 and solid volume fraction χ is varied as 0%;5%;10%;15% and 20%. The problem considered is a two-dimensional heat transfer in a square cavity. The vertical walls are differentially heated, the left is maintained at hot con- dition (sinusoidal) when the right one is cold. The horizontal walls are assumed to be insulated, non conducting and impermeable to mass transfer. The nanofluid in the enclosure is Newtonian, incompressible and laminar. The nanopar- ticles are assumed to have a uniform shape and size. Moreover, it is assumed that both the fluid phase and nanoparticles are in thermal equilibrium state and they flow at the same velocity. The thermophysical properties of the nanofluid are assumed to be constant except for the density variation in the buoyancy force, which is based on the Boussinesq approximation. Different correlations are proposed for predicting heat transfer for uniform and sinusoidal boundary thermal conditions.
文摘The equilibrium geometries,excitation energies,force constants and vibrational frequencies for the low-ly- ing electronic states X ~2B_1,~2A_1,~2B_2 and ~2A_2 of the AsH_2 radical have been calculated at the MRSDCI level with a 3-21G~* basis set.Our calculated geometries,excitation enegies and vibional frequencies for the X ~2B_1 and ~2A_1 states are in good agreement with available experimental data.The electronic transition dipole mo- ments,oscillator strengths for the ~2A_1→X ~2B_1 and ~2A_2→X ~2B_1 transitions,radiative lifetimes for the ~2A_1 and ~2A_2 states are calculated based on the MRSDC^1 wavefunctions,predicting results in reasonable agreement with available experiment.
文摘Background: Dyspepsia and heartburn are among the most frequent complaints of the upper gastrointestinal tract impacting quality of life. The present study aimed to investigate the impact of drinking a natural mineral water (medicinal product category “Heilwasser” in Germany) high in hydrogen carbonate (Staatl. Fachingen STILL) on functional dyspeptic complaints and heartburn. Methods: 56 men and women with self-reported heartburn were enrolled to this one-arm pilot study. They had to drink 1.5 L of a hydrogen carbonate rich mineral water each day over a course of six weeks. Participants reported the number and duration of heartburn episodes in a daily dairy. The Reflux Disease Questionnaire (RDQ), Quality of Life in Reflux and Dyspepsia questionnaire (QOLRAD) and the Gastrointestinal Quality of Life Index (GILQI) were used to assess the therapeutic course of the treatment and the Short Form Health Survey (SF-12) to assess general quality of life. Mean ± standard deviation were calculated and pre- and post-treatment changes were compared using the Wilcoxon test. Results: The consumption of a hydrogen carbonate rich mineral water decreased the number of heartburn episodes per week significantly by 4.8 ± 8.2 at the end of the study (p < 0.001). The duration of episodes was also significantly reduced by 25.7 minutes after six weeks of intervention (p < 0.001). Accordingly, the subjectively perceived severity of heartburn, regurgitation and dyspeptic complaints as well as the GERD dimension as assessed by Reflux Disease Questionnaire improved significantly. There was a significant improvement in the disease-specific quality of life as measured by the Gastrointestinal Quality of Life Index (p < 0.001) and by the Quality Of Life in Reflux and Dyspepsia (p < 0.001) questionnaires and the general health-related quality of life as assessed by SF-12 (p < 0.007). Conclusions: The present pilot study provides evidence that supplementation with natural mineral water rich in hydrogen carbonate may improve heartburn and dyspeptic symptoms, which finally resulted in an improvement of the subjectively perceived quality of life. Drinking mineral water rich in hydrogen carbonate may be an alternative remedy for the treatment of dyspeptic symptoms and heartburn. Trial Registration: Eudra CT No 2013-001256-36.
文摘LIRR's Priject of "Research on Spalling Mechanism Due to Rapid Heating-up of Dense Refractory Castables" declared by Wang Zhanmin,vice-president of LIRR,will gain the fund support from National Natural Science Foundation of China in 2011.
基金Phase achievement of Jiangsu Postgraduate Research Innovation Program“Research on Education Modernity Based on Zhang Junmai’s Neo-Confucianism Thought”(KYCX20_2099).
文摘In modern times,under the dual crisis of nationality and culture,Zhang Junmai returned to the internal philosophy of“Inner Sage,”whereby he started the global exploration of“Outer King”and constructed his own categorized Neo-Confucianism thoughts based on the contents of Yangming’s philosophy of mind as well as western philosophies.Therefore,by probing into the foundation of Zhang Junmai’s philosophy of mind,this paper explores the educational significance of the view of life based on honesty,the methodology of giving equal importance to learning and doing,and the world’s point of view contained in it,which may serve as a certain reference for the current education development.
基金Supported by Fund for Scientific Research of Nanjing University of Finance and Economics (B2010017)~~
文摘Based on the contents and temperament of pastoral poetries written by TAO Yuan-ming,by centering on respecting the nature,indifference and optimism,and plainness and authenticity,the paper had analyzed aesthetic ideologies contained in his poetries.On this basis,it had discussed the influence of aesthetic ideology of TAO Yuan-ming on the style of classical gardens in South China,which were quiet and natural,elegant and fresh,simple and plain,and far-reaching in artistic conception.By combining with cases,it pointed out that the poetic prose had been directly quoted as the names of gardens or scenic spots of classical gardens in South China,and showed that the aesthetic ideology of TAO Yuan-ming had set up a successful ideal model for cultural landscapes,producing far-reaching influence on the aesthetic state of mind of gardeners or owners of gardens,further instilling humanistic spirit into classical gardens in South China.