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Quantitative analysis of impact of green stormwater infrastructures on combined sewer overflow control

Jinsong Tao, Zijian Li, Xinlai Peng, Gaoxiang Ying

《环境科学与工程前沿(英文)》 2017年 第11卷 第4期 doi: 10.1007/s11783-017-0952-4

摘要: Stimulated by the recent USEPA’s green stormwater infrastructure (GSI) guidance and policies, GSI systems have been widely implemented in the municipal area to control the combined sewer overflows (CSOs), also known as low impact development (LID) approaches. To quantitatively evaluate the performance of GSI systems on CSO and urban flooding control, USEPA-Stormwater Management Model (SWMM) model was adopted in this study to simulate the behaviors of GSI systems in a well-developed urban drainage area, PSW45, under different circumstances. The impact of different percentages of stormwater runoff transported from impervious surfaces to the GSI systems on CSO and urban flooding control has also been investigated. Results show that with current buildup, GSI systems in PSW45 have the best performance for low intensity and short duration events on both volume and peak flow reductions, and have the worst performance for high intensity and long duration events. Since the low intensity and short duration events are dominant from a long-term perspective, utilizing GSI systems is considered as an effective measure of CSO control to meet the long-term control strategy for PSW45 watershed. However, GSI systems are not suitable for the flooding control purpose in PSW45 due to the high occurrence possibility of urban flooding during or after high intensity events where GSI systems have relatively poor performance no matter for a short or long duration event.

关键词: Green stormwater infrastructure (GSI)     Combined sewer overflows (CSOs)     Urban flooding     Low impact development (LID)     Stormwater Management Model (SWMM)    

Initial impacts of rain gardens’ application on water quality and quantity in combined sewer: field-scale

Isam Alyaseri, Jianpeng Zhou, Susan M. Morgan, Andrew Bartlett

《环境科学与工程前沿(英文)》 2017年 第11卷 第4期 doi: 10.1007/s11783-017-0988-5

摘要: Green infrastructures such as rain gardens can benefit onsite reduction of stormwater runoff, leading to reduced combined sewer overflows. A pilot project was conducted to evaluate the impact of rain gardens on the water quality and volume reduction of storm runoff from urban streets in a combined sewer area. The study took place in a six-block area on South Grand Boulevard in St. Louis, Missouri. The impact was assessed through a comparison between the pre-construction (2011/2012) and the post-construction (2014) phases. Shortly after the rain gardens were installed, the levels of total suspended solids, chloride, total nitrogen, total phosphorous, zinc, and copper increased. The level of mercury was lower than the detection level in both phases. was the only parameter that showed statistically significant decrease following the installation of rain gardens. The likely reason for initial increase in monitored water quality parameters is that the post-construction sampling began after the rain gardens were constructed but before planting, resulted from soil erosion and wash-out from the mulch. However, the levels of most of water quality parameters decreased in the following time period during the post-construction phase. The study found 76% volume reduction of stormwater runoff following the installation of rain gardens at one of studied sites. Statistical analysis is essential on collected data because of the encountered high variability of measured flows resulted from low flow conditions in studied sewers.

关键词: Rain gardens     Bioretention     Combined sewer     Stormwater quality and quantity    

Stormwater runoff pollution loads from an urban catchment with rainy climate in China

Liqing LI, Baoqing SHAN, Chenqing YIN

《环境科学与工程前沿(英文)》 2012年 第6卷 第5期   页码 672-677 doi: 10.1007/s11783-012-0447-2

摘要: An older urban district in Wuhan, China, is transitioning from discharging sewage and stormwater directly into lakes, to directing the sewage to wastewater treatment plants (WWTPs). Dealing with polluted stormwater discharge is a great challenge. Stormwater runoff from an urban catchment with a combined sewer system was sampled and analyzed over a three-year period. Results indicate that wet weather flows account for 66%, 31%, 17%, and 13% of the total load of suspended solids (SS), chemical oxygen demand (COD), total nitrogen, and total phosphorus, respectively. The first flush of COD and SS was significant in all runoff events. More than 50% of the SS and COD loads were transported by the first 30% of runoff volume. Storage and treatment of the first 10 mm from each combined sewer overflow event could reduce more than 70% of the annual COD overflow load. An integrated solution is recommended, consisting of a tank connected to the WWTP and a detention pond, to store and treat the combined sewer overflow (CSO). These results may be helpful in mitigating CSO pollution for many other urban areas in China and other developing countries.

关键词: combined sewer overflow     pollution load     first flush     detention basins    

Current state and future perspectives of sewer networks in urban China

Dong Huang, Xiuhong Liu, Songzhu Jiang, Hongchen Wang, Junyan Wang, Yuankai Zhang

《环境科学与工程前沿(英文)》 2018年 第12卷 第3期 doi: 10.1007/s11783-018-1023-1

摘要: Chinese authorities and the public have largely ignored sewer networks; however, various problems are emerging nationwide with the increase construction of new sewers. The current state of sewer network construction, administration, and maintenance in China is comprehensively reviewed in this study. Serving about 444 million people, 511,200 km of sewer lines are located in urban areas. In 2014, $7 billion was invested in sewer network construction. However, both the sewer pervasion rate and the per capita sewer length were significantly lower than those in developed countries. Sewer administrative agencies in local governments are uncoordinated. Laws, regulations, and standards are incomplete, and some practices are unscientific. The future situation of sewer maintenance is extremely grim because sewer corrosion control measures have not been launched. Moreover, inspection and rehabilitation chiefly rely on traditional approaches. In contrast, the overall market share of innovative technologies is very low owing to high cost, funds shortage, and technical limitations. Approaches such as liner inversion cured-in-place pipe, pull-in ultraviolet light cured liners, and spiral wound lining are applied mostly in economically developed regions. According to status and problem analyses, China’s top priority will be to conduct aggressive maintenance work in sewer networks in the future. New technical route, corrosion control - periodic visualized inspection - trenchless rehabilitation, could be the best option for future sewer maintenance in China. Instructions and opportunities for applying this technical route are discussed in detail in this study. Finally, additional factors in the development of sewer networks in China are suggested.

关键词: Sewer network     China     Management     Sewer corrosion     Sewer inspection     Trenchless rehabilitation    

Diagnosis of sewer pipe defects on image recognition of multi-features and support vector machine in

Xiangyang Ye, Jian’e Zuo, Ruohan Li, Yajiao Wang, Lili Gan, Zhonghan Yu, Xiaoqing Hu

《环境科学与工程前沿(英文)》 2019年 第13卷 第2期 doi: 10.1007/s11783-019-1102-y

摘要:

An image-recognition-based diagnosis system of pipe defect types was established.

1043 practical pipe images were gathered by CCTV robot in a southern Chinese city.

The overall accuracy of the system is 84% and the highest accuracy is 99.3%.

The accuracy shows positive correlation to the number of training samples.

关键词: Sewer pipe defects     Defect diagnosing     Image recognition     Multi-features extraction     Support vector machine    

Water-level based discrete integrated dynamic control to regulate the flow for sewer-WWTP operation

Zhengsheng Lu, Moran Wang, Mingkai Zhang, Ji Li, Ying Xu, Hanchang Shi, Yanchen Liu, Xia Huang

《环境科学与工程前沿(英文)》 2020年 第14卷 第3期 doi: 10.1007/s11783-020-1222-4

摘要: A model-free sewer-WWTP integrated control was proposed. A dynamic discrete control based on the water level was developed. The approach could improve the sewer operation against flow fluctuation. The approach could increase transport capacity and enhance pump efficiency. This study aims to propose a multi-point integrated real-time control method based on discrete dynamic water level variations, which can be realized only based on the programmable logic controller (PLC) system without using a complex mathematical model. A discretized water level control model was developed to conduct the real-time control based on data-automation. It combines the upstream pumping stations and the downstream influent pumping systems of wastewater treatment plant (WWTP). The discretized water level control method can regulate dynamic wastewater pumping flow of pumps following the dynamic water level variation in the sewer system. This control method has been successfully applied in practical integrated operations of sewer-WWTP following the sensitive flow disturbances of the sewer system. The operational results showed that the control method could provide a more stabilized regulate pumping flow for treatment process; it can also reduce the occurrence risk of combined sewer overflow (CSO) during heavy rainfall events by increasing transport capacity of pumping station and influent flow in WWTP, which takes full advantage of storage space in the sewer system.

关键词: Sewer system     Integrated control     Discrete control     Water level    

Development of combined transitional pavement structure for urban tram track-road grade crossings

《结构与土木工程前沿(英文)》   页码 1199-1210 doi: 10.1007/s11709-023-0949-y

摘要: The grade crossings and adjacent pavements of urban trams are generally subjected to complex load conditions and are susceptible to damage. Therefore, in this study, a novel pavement structure between tram tracks and roads constructed using polyurethane (PU) elastic concrete and ultra-high-performance concrete (UHPC), referred to as a track-road transitional pavement (TRTP), is proposed. Subsequently, its performance and feasibility are evaluated using experimental and numerical methods. First, the mechanical properties of the PU elastic concrete are evaluated. The performance of the proposed structure is investigated using a three-dimensional finite element model, where vehicle-induced dynamic and static loads are considered. The results show that PU elastic concrete and the proposed combined TRTP are applicable and functioned as intended. Additionally, the PU elastic concrete achieved sufficient performance. The recommended width of the TRTP is approximately 50 mm. Meanwhile, the application of UHPC under a PU elastic concrete layer significantly reduces vertical deformation. Results of numerical calculations confirmed the high structural performance and feasibility of the proposed TRTP. Finally, material performance standards are recommended to provide guidance for pavement design and the construction of tram-grade crossings in the future.

关键词: urban tram track     grade crossing     combined track-road transitional pavement     polyurethane elastic concrete     finite element method    

emissions: a comparative study of the feasibility of the hybrid renewable energy systems incorporating combined

《能源前沿(英文)》 2022年 第16卷 第2期   页码 336-356 doi: 10.1007/s11708-021-0748-x

摘要: Fuel poverty is most prevalent in North East England with 14.4% of fuel poor households in Newcastle upon Tyne. The aim of this paper was to identify a grid connected renewable energy system coupled with natural gas reciprocating combined heat and power unit, that is cost-effective and technically feasible with a potential to generate a profit from selling energy excess to the grid to help alleviate fuel poverty. The system was also aimed at low carbon emissions. Fourteen models were designed and optimized with the aid of the HOMER Pro software. Models were compared with respect to their economic, technical, and environmental performance. A solution was proposed where restrictions were placed on the size of renewable energy components. This configuration consists of 150 kW CHP, 300 kW PV cells, and 30 kW wind turbines. The renewable fraction is 5.10% and the system yields a carbon saving of 7.9% in comparison with conventional systems. The initial capital investment is $1.24 million which enables the system to have grid sales of 582689 kWh/a. A conservative calculation determined that 40% of the sales can be used to reduce the energy cost of fuel poor households by $706 per annum. This solution has the potential to eliminate fuel poverty at the site analyzed.

关键词: greenhouse gas control     low carbon target     grid connected     renewable fraction     fuel poverty     combined heat and power     HOMER Pro    

Interaction and combined toxicity of microplastics and per- and polyfluoroalkyl substances in aquatic

《环境科学与工程前沿(英文)》 2022年 第16卷 第10期 doi: 10.1007/s11783-022-1571-2

摘要:

● Adsorption of PFASs on MPs and its mechanisms are critically reviewed.

关键词: Microplastics     Per- and Polyfluoroalkyl substances     Adsorption     Transport     Transformation    

Experimental study on combined buoyant-thermocapillary flow along with rising liquid film on the surface

Manuel J. GOMES, Ning MEI

《能源前沿(英文)》 2020年 第14卷 第1期   页码 114-126 doi: 10.1007/s11708-017-0483-5

摘要: Temperature distribution and variation with time has been considered in the analysis of the influences of the initial level of immersion of a horizontal metallic mesh tube in the liquid on combined buoyant and thermo-capillary flow. The combined flow occurs along with the rising liquid film flow on the surface of a horizontal metallic mesh tube. Three different levels of immersion of the metallic mesh tube in the liquid have been tested. Experiments of 60 min in duration have been performed using a heating metallic tube with a diameter of 25 mm and a length of 110 mm, sealed outside with a metallic mesh of 178 mm by 178 mm, and distilled water. These reveal two distinct flow patterns. Thermocouples and infrared thermal imager are utilized to measure the temperature. The level of the liquid free surface relative to the lower edge of the tube is measured as angle . The results show that for a smaller angle, or a low level of immersion, with a relatively low heating power, it is possible to near fully combine the upwards buoyant flow with the rising liquid film flow. In this case, the liquid is heated only in the vicinity of the tube, while the liquid away from the flow region experiences small changes in temperature and the system approaches steady conditions. For larger angles, or higher levels of immersion, a different flow pattern is noticed on the liquid free surface and identified as the thermo-capillary (Marangoni) flow. The rising liquid film is also present. The higher levels of immersion cause a high temperature gradient in the liquid free surface region and promote thermal stratification; therefore the system could not approach steady conditions.

关键词: rising liquid film     combined flow     thermo-capillary flow     buoyant flow     metallic mesh tube     horizontal tube    

Simulation and experiments on a solid sorption combined cooling and power system driven by the exhaust

Peng GAO, Liwei WANG, Ruzhu WANG, Yang YU

《能源前沿(英文)》 2017年 第11卷 第4期   页码 516-526 doi: 10.1007/s11708-017-0511-5

摘要: A solid sorption combined cooling and power system driven by exhaust waste heat is proposed, which consists of a MnCl sorption bed, a CaCl sorption bed, an evaporator, a condenser, an expansion valve, and a scroll expander, and ammonia is chosen as the working fluid. First, the theoretical model of the system is established, and the partitioning calculation method is proposed for sorption beds. Next, the experimental system is established, and experimental results show that the refrigerating capacity at the refrigerating temperature of –10°C and the resorption time of 30 min is 1.95 kW, and the shaft power is 109.2 W. The system can provide approximately 60% of the power for the evaporator fan and the condenser fan. Finally, the performance of the system is compared with that of the solid sorption refrigeration system. The refrigerating capacity of two systems is almost the same at the same operational condition. Therefore, the power generation process does not influence the refrigeration process. The exergy efficiency of the two systems is 0.076 and 0.047, respectively. The feasibility of the system is determined, which proves that this system is especially suitable for the exhaust waste heat recovery.

关键词: solid sorption     exhaust waste heat     combined cooling and power system     exergy efficiency    

Carbon emission impact on the operation of virtual power plant with combined heat and power system

Yu-hang XIA,Jun-yong LIU,Zheng-wen HUANG,Xu ZHANG

《信息与电子工程前沿(英文)》 2016年 第17卷 第5期   页码 479-488 doi: 10.1631/FITEE.1500467

摘要: A virtual power plant (VPP) can realize the aggregation of distributed generation in a certain region, and represent distributed generation to participate in the power market of the main grid. With the expansion of VPPs and ever-growing heat demand of consumers, managing the effect of fluctuations in the amount of available renewable resources on the operation of VPPs and maintaining an economical supply of electric power and heat energy to users have been important issues. This paper proposes the allocation of an electric boiler to realize wind power directly converted for supplying heat, which can not only overcome the limitation of heat output from a combined heat and power (CHP) unit, but also reduce carbon emissions from a VPP. After the electric boiler is considered in the VPP operation model of the combined heat and power system, a multi-objective model is built, which includes the costs of carbon emissions, total operation of the VPP and the electricity traded between the VPP and the main grid. The model is solved by the CPLEX package using the fuzzy membership function in Matlab, and a case study is presented. The power output of each unit in the case study is analyzed under four scenarios. The results show that after carbon emission is taken into account, the output of low carbon units is significantly increased, and the allocation of an electric boiler can facilitate the maximum absorption of renewable energy, which also reduces carbon emissions from the VPP.

关键词: Virtual power plant (VPP)     Carbon emissions     Electric boiler     Wind power     Combined heat and power (CHP)    

Effects of combined procedure and devascularization alone on hyperdynamics of the portal venous system

HUA Rong, SUN Yongwei, WU Zhiyong

《医学前沿(英文)》 2008年 第2卷 第3期   页码 244-247 doi: 10.1007/s11684-008-0046-6

摘要: Shunts and devascularizations have totally different effects on the hemodynamics of the portal venous system. The actual results of pericardial devascularization (PCDV) alone and conventional splenorenal shunt combined with pericardial devascularization (combined procedure, CP) should be determined by more clinical observations. This study aimed to evaluate effects on hemodynamics in the portal venous system after CP and PCDV only. In 20 patients who received CP and 18 who received PCDV, hemodynamic parameters of the portal venous system were studied by magnetic resonance angiography 1 week before and 2 weeks after operation. Free portal pressure (FPP) was continuously detected by a transducer during the operations. Compared to the preoperative data, a decreased flow in the portal vein (PVF) [(563.12 ± 206.42) mL/min (1080.63 ± 352.85) mL/min, < 0.05], a decreased portal vein diameter (PVD) [(1.20 ± 0.11) cm (1.30 ± 0.16) cm, < 0.01], a decreased FPP [(21.50 ± 2.67) mmHg (29.88 ± 2.30) mmHg, < 0.01] and an increased flow in the superior mesenteric vein (SMVF) [(1105.45 ± 309.03) mL/min (569.13 ± 178.46) mL/min, < 0.05] were found in the CP group after operation; a decreased PVD [(1.27 ± 0.16) cm (1.40 ± 0.23) cm, < 0.05], a decreased PVF [(684.60 ± 165.73) mL/min (1175.64 ± 415.09) mL/min, < 0.05], a decreased FPP [(24.40 ± 3.78) mmHg (28.80 ± 3.56) mmHg, < 0.05] and an increased SMVF [(697.91 ± 121.83) mL/min (521.30 ± 115.82) mL/min, < 0.05] were observed in the PCDV group. After operation, PVF in the CP group [(563.12 ± 206.42) mL/min (684.60 ± 165.73) mL/min, > 0.05] had no significant decrease, while FPP [(21.50 ± 2.67) mmHg (24.40 ± 3.78) mmHg, < 0.01] had a significant decrease as compared with that in the PCDV group. PVF and FPP could be decreased by both surgical procedures, but the effect of decreasing FPP was much better in the combined procedure than in PCDV alone. Further, there was no significant difference in PVF between the two groups. It is suggested that the combined surgical procedure could integrate the advantages of shunting with those of devascularization, as well as maintaining the normal anatomic structure of hepatic portal system, thus it should be one of the best choices for patients with portal hypertension when surgical interventions are considered.

New method for efficient control of hydrogen sulfide and methane in gravity sewers: Combination of NaOH and Nitrite

《环境科学与工程前沿(英文)》 2022年 第16卷 第6期 doi: 10.1007/s11783-021-1509-0

摘要:

• The combination of NaOH and nitrite was used to control harmful gas in sewers.

关键词: Sewer corrosion     Sulfide control     Combination treatment     NaOH     Nitrite    

Metabolic interventions combined with CTLA-4 and PD-1/PD-L1 blockade for the treatment of tumors: mechanisms

《医学前沿(英文)》   页码 805-822 doi: 10.1007/s11684-023-1025-7

摘要: Immunotherapies based on immune checkpoint blockade (ICB) have significantly improved patient outcomes and offered new approaches to cancer therapy over the past decade. To date, immune checkpoint inhibitors (ICIs) of CTLA-4 and PD-1/PD-L1 represent the main class of immunotherapy. Blockade of CTLA-4 and PD-1/PD-L1 has shown remarkable efficacy in several specific types of cancers, however, a large subset of refractory patients presents poor responsiveness to ICB therapy; and the underlying mechanism remains elusive. Recently, numerous studies have revealed that metabolic reprogramming of tumor cells restrains immune responses by remodeling the tumor microenvironment (TME) with various products of metabolism, and combination therapies involving metabolic inhibitors and ICIs provide new approaches to cancer therapy. Nevertheless, a systematic summary is lacking regarding the manner by which different targetable metabolic pathways regulate immune checkpoints to overcome ICI resistance. Here, we demonstrate the generalized mechanism of targeting cancer metabolism at three crucial immune checkpoints (CTLA-4, PD-1, and PD-L1) to influence ICB therapy and propose potential combined immunotherapeutic strategies co-targeting tumor metabolic pathways and immune checkpoints.

关键词: CTLA-4     PD-1     PD-L1     immune checkpoint blockade (ICB)     metabolic reprogramming     combined tumor therapeutic strategies    

标题 作者 时间 类型 操作

Quantitative analysis of impact of green stormwater infrastructures on combined sewer overflow control

Jinsong Tao, Zijian Li, Xinlai Peng, Gaoxiang Ying

期刊论文

Initial impacts of rain gardens’ application on water quality and quantity in combined sewer: field-scale

Isam Alyaseri, Jianpeng Zhou, Susan M. Morgan, Andrew Bartlett

期刊论文

Stormwater runoff pollution loads from an urban catchment with rainy climate in China

Liqing LI, Baoqing SHAN, Chenqing YIN

期刊论文

Current state and future perspectives of sewer networks in urban China

Dong Huang, Xiuhong Liu, Songzhu Jiang, Hongchen Wang, Junyan Wang, Yuankai Zhang

期刊论文

Diagnosis of sewer pipe defects on image recognition of multi-features and support vector machine in

Xiangyang Ye, Jian’e Zuo, Ruohan Li, Yajiao Wang, Lili Gan, Zhonghan Yu, Xiaoqing Hu

期刊论文

Water-level based discrete integrated dynamic control to regulate the flow for sewer-WWTP operation

Zhengsheng Lu, Moran Wang, Mingkai Zhang, Ji Li, Ying Xu, Hanchang Shi, Yanchen Liu, Xia Huang

期刊论文

Development of combined transitional pavement structure for urban tram track-road grade crossings

期刊论文

emissions: a comparative study of the feasibility of the hybrid renewable energy systems incorporating combined

期刊论文

Interaction and combined toxicity of microplastics and per- and polyfluoroalkyl substances in aquatic

期刊论文

Experimental study on combined buoyant-thermocapillary flow along with rising liquid film on the surface

Manuel J. GOMES, Ning MEI

期刊论文

Simulation and experiments on a solid sorption combined cooling and power system driven by the exhaust

Peng GAO, Liwei WANG, Ruzhu WANG, Yang YU

期刊论文

Carbon emission impact on the operation of virtual power plant with combined heat and power system

Yu-hang XIA,Jun-yong LIU,Zheng-wen HUANG,Xu ZHANG

期刊论文

Effects of combined procedure and devascularization alone on hyperdynamics of the portal venous system

HUA Rong, SUN Yongwei, WU Zhiyong

期刊论文

New method for efficient control of hydrogen sulfide and methane in gravity sewers: Combination of NaOH and Nitrite

期刊论文

Metabolic interventions combined with CTLA-4 and PD-1/PD-L1 blockade for the treatment of tumors: mechanisms

期刊论文