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Contract Mechanism of Water Environment Regulation for Small and Medium Sized Enterprises Based on Optimal Control Theory
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作者 Shuang Zhao Hongbin Gu +2 位作者 Lianfang Xue Dongsheng Wang Bin Huang 《Journal of Water Resource and Protection》 CAS 2024年第7期538-556,共20页
The small and scattered enterprise pattern in the county economy has formed numerous sporadic pollution sources, hindering the centralized treatment of the water environment, increasing the cost and difficulty of trea... The small and scattered enterprise pattern in the county economy has formed numerous sporadic pollution sources, hindering the centralized treatment of the water environment, increasing the cost and difficulty of treatment. How enterprises can make reasonable decisions on their water environment behavior based on the external environment and their own factors is of great significance for scientifically and effectively designing water environment regulation mechanisms. Based on optimal control theory, this study investigates the design of contractual mechanisms for water environmental regulation for small and medium-sized enterprises. The enterprise is regarded as an independent economic entity that can adopt optimal control strategies to maximize its own interests. Based on the participation of multiple subjects including the government, enterprises, and the public, an optimal control strategy model for enterprises under contractual water environmental regulation is constructed using optimal control theory, and a method for calculating the amount of unit pollutant penalties is derived. The water pollutant treatment cost data of a paper company is selected to conduct empirical numerical analysis on the model. The results show that the increase in the probability of government regulation and public participation, as well as the decrease in local government protection for enterprises, can achieve the same regulatory effect while reducing the number of administrative penalties per unit. Finally, the implementation process of contractual water environmental regulation for small and medium-sized enterprises is designed. 展开更多
关键词 Optimal Control Theory Small and medium-Sized Enterprises water Environment Regulation Contract Mechanism
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A Comparison Study on the δD Value of Polycyclic Aromatic Hydrocarbons in Hydrous Pyrolysate of Herbaceous Peat with Different Water Medium
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作者 DUAN Yi WU Yingzhong +5 位作者 XING Lantian WU Yingqin ZHAO Yang LI Zhongping MA Lanhua DUAN Mingchen 《Acta Geologica Sinica(English Edition)》 SCIE CAS CSCD 2023年第6期1734-1743,共10页
To investigate the influence of diagenetic water media on the hydrogen isotopes of individual sedimentary aromatic compounds,a series of hydrous pyrolyses were conducted on herbaceous peat.Polycyclic aromatic hydrocar... To investigate the influence of diagenetic water media on the hydrogen isotopes of individual sedimentary aromatic compounds,a series of hydrous pyrolyses were conducted on herbaceous peat.Polycyclic aromatic hydrocarbons(PAHs)in hydrous pyrolysed samples and their hydrogen isotopic composition characteristics were studied.The aqueous medium demonstrated a significant influence on the hydrogen isotopic composition of the individual PAHs generated during pyrolysis.The results showed that the PAHs formed after pyrolysis in the presence of a saltwater medium with high δD value from a salt lake had a heavy hydrogen isotopic composition.The PAHs formed after pyrolysis in the presence of a fresh water medium with low δD value from a swamp had a light hydrogen isotopic composition.The difference in the average PAHδD value between the two hydrous experiments varied from -174‰ to -109‰,suggesting that the hydrogen isotopic composition of individual sedimentary PAHs can reflect the source of the diagenetic water medium.In addition,a comparative study found that the hydrogen isotopes of PAHs were superior to those of n-alkanes in the same sample for diagenetic water indications.The results indicated that the exchange of water-derived inorganic hydrogen and organic hydrogen was more intensive in freshwater experiments than in saltwater experiments.With an increase in the simulation temperature,the average δD value of PAHs generated in the hydrous simulation experiments showed an increasing trend,reflecting that the δD value of sedimentary PAHs formed with the participation of diagenetic water media was still closely related to the thermal maturity of organic matter.Comparative studies showed that theδD values of different types of organic compounds produced by hydrous pyrolysis of peat were in the order,PAHs>n-alkanes>methane. 展开更多
关键词 hydrogen isotope PAHS hydrous pyrolysis herbaceous peat water medium
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Propagation of Abies beshanzuensis by Water Cultured Medium 被引量:4
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作者 饶龙兵 吴友贵 《Agricultural Science & Technology》 CAS 2009年第3期43-45,54,共4页
[Objective] The experiment aimed to explore the influences of phytohormones (ABT and IAA) and nutrient solution on rooting of Abies beshanzuensis M.H.Wu by water cultured medium. [Method] The Abies beshanzuensis M.H.W... [Objective] The experiment aimed to explore the influences of phytohormones (ABT and IAA) and nutrient solution on rooting of Abies beshanzuensis M.H.Wu by water cultured medium. [Method] The Abies beshanzuensis M.H.Wu were treated by water (CK), 10 mg/L ABT+ water, 10 mg/L IAA+ water, 10 mg/L ABT+ hoagland solution, 10 mg/L IAA+ hoagland solution, then the rooting process was observed and the formation rate of callus, rooting rate, number of rooting, and root length were investigated and analyzed. [Result] ABT and IAA had obvious influences on callus induction, rooting rate and the number of root of Abies beshanzuensis M.H.Wu by water culture, so they were suitable to be used in water propagation of Abies beshanzuensis M.H.Wu. The treatments of phytohormones had no regular influences on the longest root length and average root length. The nutrient solutions would not generate obvious influence on propagation of Abies beshanzuensis M.H.Wu at firstly stage, but they generated influence on root growth after rooting. [Conclusion] The research provided new ideas for propagation of Abies beshanzuensis M.H.Wu, which could make it out of endangerment situation quickly. 展开更多
关键词 Abies beshanzuensis M. H. Wu Propagation water cultured medium Phytohormones Solution
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Influence of light intensity and water content of medium on total dendrobine of Dendrobium nobile Lindl 被引量:7
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作者 Jin-Ling Li Zhi Zhao +2 位作者 Hong-Chang Liu Chun-Li Luo Hua-Lei Wang 《Asian Pacific Journal of Tropical Medicine》 SCIE CAS 2017年第11期1095-1100,共6页
Objective: To ascertain the influence of light intensity and water content of medium on the total dendrobine of Dendrobium nobile(D. nobile).Method: The principal component analysis combined with total dendrobine accu... Objective: To ascertain the influence of light intensity and water content of medium on the total dendrobine of Dendrobium nobile(D. nobile).Method: The principal component analysis combined with total dendrobine accumulation was conducted to assess the yield and quality of D. nobile in all treatments. In the experiment, D. nobile plants were cultivated in greenhouse as tested materials, and complete test of 9 treatments was adopted with relative light intensities 75.02%, 39.74%,29.93% and relative water content of medium 50%, 65%, 80%. The plants were treated in June and harvested till December. Indexes including agronomic traits, fresh weight and dry weight of stem and leaf, ash content, extract, and dendrobine were measured.Results: Under the light intensity treatments of 75.02% with 50%, 65%, 80% water content of medium, the basal stems of plants were comparatively thicker with more leaves, and the fresh weight and dry weight of stems and leaves were significantly higher than other 6 treatments.Leaves in all treatments contained dendrobine. Under the light intensity treatments of 75.02%with 50%, 65%, 80% water content of medium, dendrobine content of leaves was lower while dendrobine contents of other treatments were more than 0.60%. After comprehensive assessment through the principal component analysis and total dendrobine accumulation, the results showed that 3 treatments with relative light intensity of 75.02% ranked the top three.Conclusions: In brief, the moderately strong light intensity and water content of medium from low to medium can facilitate the growth and yield of D. nobile plants, while light intensity from moderately weak to weak can enhance the dendrobine content. 展开更多
关键词 Dendrobium nobile Light intensity water content of medium Total dendrobine Principal component analysis
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Comparison of Absorbed Dose to Medium and Absorbed Dose to Water for Spine IMRT Plans Using a Commercial Monte Carlo Treatment Planning System 被引量:1
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作者 Muhammad Nauman Usmani Norihisa Masai +5 位作者 Ryoong-Jin Oh Hiroya Shiomi Daisaku Tatsumi Hideharu Miura Toshihiko Inoue Masahiko Koizumi 《International Journal of Medical Physics, Clinical Engineering and Radiation Oncology》 2014年第1期60-66,共7页
Dose in radiation therapy has been reported as the water-equivalent dose using conventional dose calculation algorithms. The Monte Carlo (MC) algorithm employs characterization of human tissues by elemental compositio... Dose in radiation therapy has been reported as the water-equivalent dose using conventional dose calculation algorithms. The Monte Carlo (MC) algorithm employs characterization of human tissues by elemental composition and mass density. It enables more accurate dose calculation for radiation therapy treatment planning and typically reports absorbed dose to medium. Whether one should use dose to medium or tissue (Dm) in place of dose to water (Dw) for MC treatment planning remains the subject of debate. The aim of the current study is to evaluate the differences between dose-volume indices for Dm and Dw MC-calculated IMRT plans. Thirty-seven spine patients were selected for this study. The IMRT optimization and MC calculations were performed using the iPlan RT DoseTM ver 4.1.2 (Brainlab, Munich, Germany) treatment planning system (TPS) with an X-ray Voxel Monte Carlo (XVMC) dose calculation engine. Dw and Dm results for target and critical structures were evaluated using the dose-volume-based indices. Systematic differences between dose-volume indices computed with Dw and Dm were up to 5.2%, 4.2%, and 4.5% for D2, D50 and D98 indices of the clinical target volume (CTV), respectively and up to 1% for the critical structure dose indices. Our study demonstrates that employing Dm in place of Dw in MC-calculated IMRT treatment plans introduces a significant systematic difference in target DVHs. We recommend that for diffused target structures (such as spine tumors), dose to water is a better quantity for dose prescription in photon beam treatment planning using existing MC TPS. While for critical structures, it would be reasonable to report Dm always. However in future with the availability of finer spatial resolution, Dm will be the most suitable variable for both target and critical structures’ dose prescription and reporting in MC treatment planning. 展开更多
关键词 DOSE to medium DOSE to water Monte Carlo IMRT
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Porous Haydite Used as Waste Water Filter Medium for Lake Sludge
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作者 何永佳 ZHAO Qiang +1 位作者 U Linnu HU Shuguang 《Journal of Wuhan University of Technology(Materials Science)》 SCIE EI CAS 2013年第3期544-547,共4页
Porous haydite used as waste filter medium was prepared by dreging lake sludge to help solve the treatment problem of sludge and realize its reclamation. Several calcination regimes were considered and their effects o... Porous haydite used as waste filter medium was prepared by dreging lake sludge to help solve the treatment problem of sludge and realize its reclamation. Several calcination regimes were considered and their effects on the pore structure and the properties such as the strength, the density, the filtering ability and the phosphate absorption ability of the haydite were investigated, For the mixture of 60% lake sludge and 40% fly ash in this experiment, the calcination regime with a pre-caleination period at about 600℃, a temperature keeping period at 1 200 ℃ and a moderate cooling rate are recommended to prepare haydite with reasonable pore structure and good performances for its usage as the waste water filter media. 展开更多
关键词 filter medium haydite lake sludge waste water
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Effect of Hypomagnetic Field on Water Medium of Living Systems
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作者 Svetlana Stepanovna Moisa Vladimir Vladimirovich Tsetlin Elena Leonidovna Nefedova 《Journal of Biomedical Science and Engineering》 2019年第12期545-556,共12页
The article represents the generalizing data for the studying of the effect of hypomagnetic field on physico-chemistry properties of water and bio-objects. It was revealed the changing state of water: increasing of it... The article represents the generalizing data for the studying of the effect of hypomagnetic field on physico-chemistry properties of water and bio-objects. It was revealed the changing state of water: increasing of its oxidation-reduction potential and oxidative properties as magnetic induction attenuated pointing to a natural decline, that testifies about the regular decreasing of internal energy of water molecules, which, in our opinion, is caused the inhibition of the germination of seeds of the highest plants, embryonic development of Planorbarius corneus and the changing of energy state of growing mediums for cell culture of mammals. It is supposed that namely the changing state of water is the main component in the effects of weakening of magnetic field on the studying bio-objects. 展开更多
关键词 Hypomagnetic FIELD water medium Oxidation-Reduction PROPERTIES LIVING Systems
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Numerical Investigations on Hydrodynamic Performance of An Open Comb-Type Breakwater Under Medium Water Levels
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作者 FANG Zhuo CHENG Liang +3 位作者 ZANG Zhi-peng SHEN Chen TIAN Ying-hui CHENG Ning 《China Ocean Engineering》 SCIE EI CSCD 2021年第6期866-877,共12页
The comb-type breakwater(CTB)has been proposed and investigated in recent years due to its advantages in terms of deep-water adaptability,material saving and water exchanges.All existing empirical formulae for CTBs ha... The comb-type breakwater(CTB)has been proposed and investigated in recent years due to its advantages in terms of deep-water adaptability,material saving and water exchanges.All existing empirical formulae for CTBs have been so far restricted to the water level above the bottom of the superstructure,which mainly occurs under the high tides or storm tides.However,based on recent engineering applications and experimental observations,the most severe conditions for CTBs are more likely to occur under a medium water level,because impulsive wave pressure may occur due to interactions between waves and the special chamber in CTBs.Meanwhile,during the most of construction and operation periods,the CTBs are mainly working under the medium water levels,i.e.,water levels below the bottom of the superstructure.In this study,the effects of main influence parameters on the horizontal wave force coefficient and wave transmission coefficient for open CTBs(with partially immersed side plates)under medium water levels were investigated based on a 3D numerical wave flume and corresponding empirical formulae were proposed.It is indicated that the location of the side plate related to the main caisson has significant influence on the hydrodynamic performance of CTBs.In engineering applications,the location of the side plate can be designed at b/L≤0.15 or b/L≥0.3(where b is the distance between the side plate and the front face of the main caisson and L is the incident wave length)for efficiently lowering the horizontal wave force and wave transmission.The flow mechanism of impulsive wave force on CTBs was revealed based on synchronous analyses of flow fields and pressure distribution.Through appropriate design of the height of the superstructure according to H/hD≤1.0 or H/hD≥1.5(where H is the incident wave height and hD is the distance between the still water level and the bottom of the superstructure),the likely impulsive wave pressure on the side plate can also be diminished. 展开更多
关键词 numerical wave flume open comb-type breakwater horizontal wave force coefficient transmission coefficient medium water level
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Development of Heat Transfer Coefficient and Friction Factor Correlations for Serrated Fins in Water Medium using CFD
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作者 K V Ramana Murthy C Ranganayakulu T P Ashok Babu 《Journal of Physical Science and Application》 2015年第3期238-248,共11页
Abstract: The most popularly used fin types in compact heat exchangers are the serrated fins, wavy fins, louvered fins and plain fins. Amongst these fin types the serrated fins assume lot of importance due to its enh... Abstract: The most popularly used fin types in compact heat exchangers are the serrated fins, wavy fins, louvered fins and plain fins. Amongst these fin types the serrated fins assume lot of importance due to its enhanced thermo-hydraulic performance. Thermo-hydraulic design of CHEs (Compact heat exchangers) is strongly dependent upon the predicted/measured dimensionless performance (Colburnj factor and Fanning friction vs. Reynolds number) of heat transfer surfaces. This paper describes the numerical analysis to study the heat transfer coefficient and friction factor of Serrated fins in water medium. CFD (Computational fluid dynamics) methodology has been used to develop the single phase water heat transfer coefficient and friction factor correlations for serrated fins using ANSYS Fluent 14.5. The results are compared with previous air-cooled models and experimental results of water. The water cooled CFD analysis results shows that the Prandtl number has a large effect on the Nusselt number of the serrated fin geometry. Finally, the generalized correlations are developed for serrated fins taking all geometrical parameters into account. This numerical estimation can reduce the number of tests/experiments to a minimum for similar applications. 展开更多
关键词 Compact heat exchanger serrated fins CFD (Computational fluid dynamics) analysis water medium thermo-hydraulicperformance colburnj factor friction factors
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Comparison of Gamma Pass Rate between the Dose-to-Water and Dose-to-Medium Reporting Modes for Patient-Specific QA Using a Helical Diode Array Dosimeter with a Fixed Phantom Density
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作者 Hideaki Hirashima Mitsuhiro Nakamura +7 位作者 Yoshitomo Ishihara Nobutaka Mukumoto Mami Akimoto Tsuneyuki Tomita Yoshinori Hirose Kenji Kitsuda Takashi Ishigaki Takashi Mizowaki 《International Journal of Medical Physics, Clinical Engineering and Radiation Oncology》 2018年第1期74-86,共13页
Introduction: To compare the measured dose distributions to calculated ones in dose-to-water (Dw) and dose-to-medium (Dm) reporting modes for simple plans and patient-specific intensity modulated radiation therapy (IM... Introduction: To compare the measured dose distributions to calculated ones in dose-to-water (Dw) and dose-to-medium (Dm) reporting modes for simple plans and patient-specific intensity modulated radiation therapy (IMRT) and volumetric modulated arc therapy (VMAT) plans using ArcCHECK with a fixed phantom density. Methods: The recommended density value of 1.18 g/cm3 for Acuros XB and X-ray voxel Monte Carlo was assigned to ArcCHECK on CT images. A total of 45 simple plans, including a 1-field plan, a 3-field plan, a 4-field plan, a half-arc plan from 270° to 90°, and a full-arc plan, were assessed. Subsequently, the patient-specific 96 IMRT and VMAT plans were evaluated. Gamma analysis with a 3% normalized global dose error and a 3 mm distance-to-agreement criteria (γ3%G/3mm) was performed in the Dw and Dm. The change in γ3%G/3mm between Dw and Dm were statistically analyzed using JMPPro11 software. Results: The median values of γ3%G/3mm for all simple plans for Dw and Dm were 98.1% (range, 75.2% - 100%) and 95.5% (range, 23.7% - 100%), respectively (p 0.01). In the patient-specific IMRT and VMAT plans, the median values of γ3%G/3mm for Dw and Dm were 98.6% (range, 90.1% - 100%) and 90.5% (range, 38.5% - 97.2%), respectively (p 0.01). Conclusion: Our results showed that the calculated and measured dose distributions were in good agreement for Dw, but were not for Dm. From the viewpoint of the rationale of dosimetry, Dw shows better agreement with measured dose distribution when using the fixedphantom density recommended by the vendor. 展开更多
关键词 HELICAL Diode Array DOSIMETER Dose-to-water Dose-to-medium GAMMA Pass Rate
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Optimization design of wide face water slots for medium-thick slab casting mold
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作者 Xue-lin Yin Li Wu +6 位作者 Jun-jia Zhang Hui-jun Kang Zong-ning Chen Jin-song Chen Zhi-qiang Cao Ting-ju Li Tong-min Wang 《China Foundry》 SCIE 2016年第5期327-334,共8页
A three-dimensional finite-element model has been established to investigate the thermal behavior of the medium-thick slab copper casting mold with different cooling water slot designs. The mold wall temperatures meas... A three-dimensional finite-element model has been established to investigate the thermal behavior of the medium-thick slab copper casting mold with different cooling water slot designs. The mold wall temperatures measured using thermocouples buried in different positions of the mold with the original designed cooling system were analyzed to determine the corresponding heat flux profile. This profile was then used for simulation to predict the temperature distribution and the thermal stress distribution of the molds. The predicted temperatures during operation matched the plant measurements. The results showed that the maximum temperature, about 635 K in the wide hot surface, was found about 60 mm below the meniscus and 226 mm from the center of the mold. For the mold with the type I modified design, there was an insignificant decrease in temperature of about 5 K, and for the mold with the type II modified design, the maximum temperature was decreased by about 15 K and the temperature of the hot surface was distributed more uniformly along the length of the mold. The corresponding maximum thermal stress at the hot surface of the mold was reduced from 408 MPa to 386 MPa with the type II modified design. The results indicated that the modified design II is beneficial to the increase of mold life and the quality of casting slabs. 展开更多
关键词 medium-thick slab casting mold water slots design heat flux profile thermal behavior finiteelement analysis
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中深层地埋管热泵供热系统运行特性实测研究 被引量:2
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作者 邓杰文 彭晨玮 +5 位作者 朱超 李骥 孔维政 李建峰 强文博 魏庆芃 《暖通空调》 2024年第4期113-119,共7页
通过大量工程实测研究,总结了中深层地埋管热泵供热技术的运行特性。中深层地埋管具有出水温度高、取热功率大、长期运行稳定的特点,为热泵系统提供了高品位的低温热源,以提升其运行性能;同时中深层地埋管自身存在间歇蓄热特性,能很好... 通过大量工程实测研究,总结了中深层地埋管热泵供热技术的运行特性。中深层地埋管具有出水温度高、取热功率大、长期运行稳定的特点,为热泵系统提供了高品位的低温热源,以提升其运行性能;同时中深层地埋管自身存在间歇蓄热特性,能很好地满足建筑供热需求变化与柔性用能;无级变频热泵机组更适合与中深层地埋管匹配运行,节能减排效果显著;热源侧水系统具有小流量、大扬程,且阻力随着流量变化而大幅度变化的特性。研究结果可为提升该技术的供热性能提供关键指导。 展开更多
关键词 中深层地埋管 热泵系统 热源侧水系统 运行特征 阻力特性 实测研究
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削痂清创与水刀清创治疗中面积深Ⅱ度烧伤创面的临床效果比较
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作者 刘礼平 邓涛 朱鹏 《中国医学创新》 CAS 2024年第15期131-135,共5页
目的:比较中面积深Ⅱ度烧伤患者应用削痂清创与水刀清创治疗的临床效果。方法:选取2021年1月—2023年3月吉安市中心人民医院收治的中面积深Ⅱ度烧伤患者,共82例,按照随机数字表法分成水刀清创组(41例)与削痂清创组(41例)。水刀清创组采... 目的:比较中面积深Ⅱ度烧伤患者应用削痂清创与水刀清创治疗的临床效果。方法:选取2021年1月—2023年3月吉安市中心人民医院收治的中面积深Ⅱ度烧伤患者,共82例,按照随机数字表法分成水刀清创组(41例)与削痂清创组(41例)。水刀清创组采用水刀清创治疗,削痂清创组采用削痂清创治疗。比较两组临床指标、预后情况、创面愈合质量、炎症因子及疼痛介质。结果:水刀清创组每1%面积清创时间、创面愈合时间、住院时间均较削痂清创组短,创面细菌菌落数更少,差异均有统计学意义(P<0.05)。相较削痂清创组,水刀清创组二次清创率更低,差异有统计学意义(P<0.05)。相较削痂清创组,水刀清创组改良温哥华瘢痕评估量表(mVSS)评分均更低,差异均有统计学意义(P<0.05)。治疗后,两组降钙素原(PCT)、C反应蛋白(CRP)水平均较治疗前下降,相较削痂清创组,水刀清创组均更低,差异均有统计学意义(P<0.05)。治疗后,两组5-羟色胺(5-HT)、神经肽Y(NPY)水平均较治疗前下降,相较削痂清创组,水刀清创组均更低,差异均有统计学意义(P<0.05)。结论:与削痂清创比较,中面积深Ⅱ度烧伤患者应用水刀治疗的效果更好,能够改善临床指标及预后情况,促进创面良好愈合,调节炎症因子、疼痛介质水平。 展开更多
关键词 中面积深Ⅱ度烧伤创面 削痂清创 水刀
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水源热泵回灌中大肠杆菌阻塞迁移沉积特性参数试验研究
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作者 赵军 汪瑶 《太阳能学报》 EI CAS CSCD 北大核心 2024年第7期415-419,共5页
以地下水源热泵回灌过程中大肠杆菌堵塞作为研究对象,通过自主研发的砂层颗粒迁移-沉积试验系统观察大肠杆菌在多孔介质孔隙孔道内的运移、沉积。以3种不同长度的试验箱体开展大肠杆菌在多孔介质里的运移沉积规律,通过试验得出:1)石英... 以地下水源热泵回灌过程中大肠杆菌堵塞作为研究对象,通过自主研发的砂层颗粒迁移-沉积试验系统观察大肠杆菌在多孔介质孔隙孔道内的运移、沉积。以3种不同长度的试验箱体开展大肠杆菌在多孔介质里的运移沉积规律,通过试验得出:1)石英石颗粒内部的内摩擦力有利于大肠杆菌的沉积,流动速度对大肠杆菌引起的微生物堵塞起到关键作用:2)3种(60、80、100 cm)不同长度的试验箱体在流速作用下以100和80 cm为对象,其沉积率提高了57.1%;以80和60 cm为对比对象,其沉积率提高了27.3%;3)大肠杆菌的恢复率与流体速度也成正相关作用,其堵塞原理类似沉积率特性。 展开更多
关键词 地下水源热泵 大肠杆菌 多孔介质 沉积特性 迁移沉积 试验系统
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水介质中冰-桥墩碰撞动力响应分析
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作者 贡力 董洲全 +2 位作者 杨腾腾 崔越 杜云飞 《振动与冲击》 EI CSCD 北大核心 2024年第11期72-82,共11页
为准确模拟冰-桥墩碰撞过程中墩体结构的动力响应,基于流固耦合(fluid-solid interaction, FSI)的计算方法,运用ANSYS/LS-DYNA软件数值模拟了水介质中冰排与桥墩在不同碰撞影响参数下的动力响应。结果表明:恒定附加质量(constant added ... 为准确模拟冰-桥墩碰撞过程中墩体结构的动力响应,基于流固耦合(fluid-solid interaction, FSI)的计算方法,运用ANSYS/LS-DYNA软件数值模拟了水介质中冰排与桥墩在不同碰撞影响参数下的动力响应。结果表明:恒定附加质量(constant added mass, CAM)模型相比FSI模型冰载荷计算结果偏大,是因为CAM模型忽略了降低冰排速度的“水垫效应”,但其计算效率高,计算时间是FSI模型的1/10,更有利于桥墩防撞设计,而FSI模型能够更真实地模拟冰-桥墩碰撞场景。综合分析该研究所模拟的不同冰排工况,发现桥墩在冰排撞击作用下呈现明显的冰激结构振动特征,桥墩侧向位移云图随着应力波的传递呈现明显的层状分布,其顶部侧向位移幅度最大,因此在工程设计时应充分考虑其对桥梁整体安全的影响;随着冰排速度、冰排厚度和冰排压缩强度的增大,冰载荷平均值均呈现近似多项式函数关系。此外,研究发现当冰排压缩强度小于2.668 MPa(环境温度高于-15℃)时,冰载荷平均值明显减小,表明环境温度的变化对于桥墩受冰排撞击挤压作用所受的冰害问题具有显著的差异。其仿真研究成果拟为桥梁及桥墩防撞设施设计提供参考。 展开更多
关键词 数值模拟 流固耦合 冰载荷 桥墩 水介质
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跨介质出水航行器水下信息获取技术发展与展望
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作者 张旭 李万鹏 《水下无人系统学报》 2024年第4期659-667,共9页
跨介质航行器出水过程中存在多相流、空泡非定常演化、强瞬态效应及载荷环境突变等特征,对航行器的稳定航行、出水姿态和结构强度有着显著影响。为充分认识和验证航行器在海洋环境下的出水性能,需发展与其工况相适应的水下信息获取技术... 跨介质航行器出水过程中存在多相流、空泡非定常演化、强瞬态效应及载荷环境突变等特征,对航行器的稳定航行、出水姿态和结构强度有着显著影响。为充分认识和验证航行器在海洋环境下的出水性能,需发展与其工况相适应的水下信息获取技术。文中总结了跨介质出水航行器试验中的目标定位、景象观测、环境测量及跨介质信息传输等水下信息获取技术研究现状,分析了高动态以及大深度等新质跨介质航行器发展对水下信息获取技术提出的新需求,展望了其体系化、多模化和数字化发展趋势,为探索解决水下高价值信息获取难题,以及更深入掌握水下复杂环境和解译水下关键过程提供思路和技术上的参考。 展开更多
关键词 跨介质航行器 出水 水下信息获取 海洋环境
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双层多孔板结构相变发汗冷却的数值模拟研究 被引量:1
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作者 刘韬略 吕玉妹 +2 位作者 栾芸 贺菲 王建华 《力学学报》 EI CAS CSCD 北大核心 2024年第1期121-129,共9页
为了提高相变发汗冷却的冷却性能,提出不同孔隙率组合的双层多孔板结构设计代替传统的单层多孔板结构.以液态水作为冷却剂,使用修正后的局部热非平衡两相混合流模型,数值研究了不同孔隙率组合的多孔板内流-固耦合传热和冷却剂流动输运特... 为了提高相变发汗冷却的冷却性能,提出不同孔隙率组合的双层多孔板结构设计代替传统的单层多孔板结构.以液态水作为冷却剂,使用修正后的局部热非平衡两相混合流模型,数值研究了不同孔隙率组合的多孔板内流-固耦合传热和冷却剂流动输运特性.数值模拟结果表明存在可以降低结构表面温度的双层多孔板设计,并且在冷却剂流量较大、液体水相变发生在上层多孔板内时,该新型结构相较于传统结构的表面温度降低更为明显.与此同时,冷却剂的注射压力被重点关注.由于水蒸气的运动黏度远高于液体水,研究中发现当冷却剂相变发生在多孔板内时,冷却剂的注射压力主要取决于水蒸气所集中的上层多孔板孔隙率.因此基于多孔介质内的渗流特性,采用孔隙率较大的上层多孔板有助于降低结构内的水蒸气压力,从而实现多孔板板底冷却剂注射压力的降低,在某一孔隙率组合中冷却剂注射压力的最大降幅可以达到65%.如果采用相反的孔隙率设计,即下层多孔板的孔隙率较大,虽然也可以在一定程度上降低表面温度,但是注射压力将会数倍增加,不利于相变发汗冷却的实际应用. 展开更多
关键词 发汗冷却 水相变 多孔介质 热防护
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优质中强筋春小麦新品种陇春44号选育报告 被引量:1
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作者 杨长刚 柳娜 +4 位作者 张雪婷 王世红 杨文雄 袁俊秀 刘效华 《寒旱农业科学》 2024年第6期538-542,I0004,共6页
优质、节水、广适品种是河西走廊灌区及相似生态区春小麦生产可持续发展的关键。陇春44号是以99W77-6-1-2/龙96-4839//m^(2)48为三交组合,采用系谱法选育出的春小麦新品种,该品种在2020—2021年甘肃省西片水地春小麦区域试验中折合产量... 优质、节水、广适品种是河西走廊灌区及相似生态区春小麦生产可持续发展的关键。陇春44号是以99W77-6-1-2/龙96-4839//m^(2)48为三交组合,采用系谱法选育出的春小麦新品种,该品种在2020—2021年甘肃省西片水地春小麦区域试验中折合产量为8263.8 kg/hm^(2),比对照品种宁春4号增产10.2%;生产试验产量达8753.9 kg/hm^(2),比对照品种宁春4号增产9.0%。节水指数达1.203~1.276,节水级别为2级。成株期田间表现慢锈性,中抗白粉病。品质达中强筋小麦标准。适宜在甘肃省水地春小麦类型区种植,也可在西北类似生态区种植。 展开更多
关键词 春小麦 新品种 陇春44号 节水 中强筋 选育
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黄河流域中小河流水质评价的比较研究 被引量:2
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作者 史陈雪 刘庆庆 +3 位作者 杨艳霞 安东妹 刘玥 祖国峰 《河南师范大学学报(自然科学版)》 CAS 北大核心 2024年第1期16-27,I0004,共13页
我国中小河流众多,流域面积覆盖了全国85%的城镇及广大农村地区,是区域生产生活用水的主要来源和污染负荷排放的接纳者.开展中小河流水质综合评价对于客观、准确地评价水环境质量状况,制订水污染防治整体规划具有重要意义.以黄河流域河... 我国中小河流众多,流域面积覆盖了全国85%的城镇及广大农村地区,是区域生产生活用水的主要来源和污染负荷排放的接纳者.开展中小河流水质综合评价对于客观、准确地评价水环境质量状况,制订水污染防治整体规划具有重要意义.以黄河流域河南省2条典型中小河流为研究对象,在识别河流水污染状况的基础上,采用单因子评价法、综合污染指数法、水质标识指数法和模糊综合评价4种方法对水质现状进行了综合评价,探讨了不同方法在中小河流水质评价中的适用性.结果表明:2条中小河流主要污染指标为NH_(3)-N、挥发酚及TP;水质标识指数法的评价结果与可靠性分析中的水质评价结果一致性最高,该方法得到的水质类别结果更加可靠. 展开更多
关键词 中小河流 单因子评价法 综合污染指数法 水质标识法 模糊综合评价
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多介质过滤处理农村灰水影响因素实验研究 被引量:1
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作者 申晋榕 李桂兰 +2 位作者 刘建国 冷娟 曹思雨 《水处理技术》 CAS CSCD 北大核心 2024年第2期116-120,共5页
为寻求多介质过滤技术处理农村灰水的可行性及最佳运行条件,以内蒙古呼和浩特市某村生活灰水为研究对象,选择玉米茎、陶粒、活性炭作为过滤介质构建多介质过滤系统处理农村灰水,研究滤速、介质配比、进水LAS、COD、SS浓度和温度等影响... 为寻求多介质过滤技术处理农村灰水的可行性及最佳运行条件,以内蒙古呼和浩特市某村生活灰水为研究对象,选择玉米茎、陶粒、活性炭作为过滤介质构建多介质过滤系统处理农村灰水,研究滤速、介质配比、进水LAS、COD、SS浓度和温度等影响因素对多介质过滤系统处理效果的影响。结果表明多介质过滤处理农村灰水的最佳滤速为0.26 m/h;介质配比玉米茎∶陶粒∶活性炭为1.5∶2∶0.5;多介质过滤系统处理灰水中LAS、COD、SS的浓度限值为30、300、300 mg/L;温度为2℃时,系统出水仍满足农田灌溉水质标准(GB 5084-2021)。研究表明,多介质过滤技术对农村灰水有较好的处理效果,降低农村灰水处理设备建设和运行成本,有利于农村污水就地回用资源化利用。 展开更多
关键词 农村灰水 多介质过滤 影响因素 玉米茎
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