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Scale study of sites and pavilions for World Expo 2010

ZHOU Zhuoyan, CHEN Yi

《结构与土木工程前沿(英文)》 2008年 第2卷 第1期   页码 102-106 doi: 10.1007/s11709-008-0012-z

摘要: The scale of sites and pavilions for World Expo 2010 (Shanghai World Expo) mainly refers to the study of their size including the area and number of exhibition hall needed in each pavilion and site with appropriate waiting area. All the design data of scale studied should reasonably meet the requirements during World Expo 2010 to accommodate large number of people for visiting and waiting to the full.

关键词: pavilion     study     number     appropriate     design    

Practicality study on air-powered vehicle

LIU Lin, YU Xiaoli

《能源前沿(英文)》 2008年 第2卷 第1期   页码 14-19 doi: 10.1007/s11708-008-0004-7

摘要: To investigate the feasibility and outlook of air-powered vehicles including compressed air-powered vehicle and liquid nitrogen-powered vehicle, thermodynamic analysis and experiment data were used to analyze the energy density, performance, safety, running efficiency, fuel circulation economy and consumer acceptance, etc. The results show that compressed air and liquid nitrogen have similar energy density as Ni-H battery; the characteristics of an air-powered engine is suitable for driving a vehicle; the circulation efficiency of liquid nitrogen is 3.6%–14% and that of compressed air is 25%–32.3% in practice, and existing technology can assure its safety. It is concluded that though the performance of an air-powered engine is inferior to that of the traditional inert combustion engine, an air-powered vehicle is fit for future green cars to realize the sustainable development of society and environment.

Experimental study on shear behavior of prestressed reactive powder concrete I-girders

Hui ZHENG, Zhi FANG, Bin CHEN

《结构与土木工程前沿(英文)》 2019年 第13卷 第3期   页码 618-627 doi: 10.1007/s11709-018-0500-8

摘要: As a new generation of concrete, RPC(Reactive Powder Concrete) has attracted great research attention for its ultra-high strength and high durability. In the present paper, experimental results from tests on eight prestressed RPC I-section girders failing in shear are reported herein. The beams with RPC of 120 MPa in compression were designed to assess the ability to carry shear stress in thin webbed prestressed beams with stirrups. The test variables were the level of prestressing, shear span-depth ratio ( / ) and stirrup ratio. Shear deformation, shear capacity and crack pattern were experimentally investigated in detail. With regard to the shear resistance of the test beams, the predictions from three standards (AFGC, JSCE and SIA) on the design of UHPC structures were compared with the experimental result suggesting that the experimental strength is almost always higher than predicted. RPC, as a new concrete, was different from normal concrete and fiber reinforced concrete. Further study should be needed to develop an analytical method and computation model for shear strength of RPC beams.

关键词: prestressed concrete     RPC(Reactive Powder Concrete)     concrete beams     shear strength     experimental study    

A feasibility study of the measuring accuracy and capability of wireless sensor networks in tunnel monitoring

Xiaojun LI, Zhong JI, Hehua ZHU, Chen GU

《结构与土木工程前沿(英文)》 2012年 第6卷 第2期   页码 111-120 doi: 10.1007/s11709-012-0150-1

摘要: Fire disasters and the deterioration of tunnel structures are major concerns for tunnel operation and maintenance. Traditional wired monitoring systems have many drawbacks in terms of installation time, overall cost, and flexibility in tunnel environments. In recent years, there has been growing interest in the use of wireless sensor networks (WSNs) for the monitoring of various structural monitoring applications. This paper evaluated the feasibility of applying a WSN in the monitoring of tunnels. The monitoring requirements of tunnels under explosion and combustion fire scenarios are analyzed using numerical simulation, and the maximum possible distance for temperature sensors is derived. The displacement monitoring of tunnels using an inclinometer is investigated. It is recommended that the inclinometer should be installed in the 1/4 span of the tunnel structure. The maximum wireless transmission distances in both outdoor and tunnel environments were examined. The influences of surface materials and sensor node locations on the data transmission distance in tunnel environments were also investigated. The experimental results show that the data loss in tunnel environments is approximately three times that in outdoor environments. Surface material has a considerable influence on the transmission distance of radio signals. The distance is 25 ? 28 m for a raw concrete surface, 20 m for a brick surface, and 36 m for a terrazzo surface. The transmission distances along the middle of quarter points are approximately 0.9 ( is the transmission distance in the center of the tunnel), and the relative error is less than±3%. The transmission distances at different locations along the bottom exhibit significant differences, decreasing from the middle to the corner point, with distances of approximately 0.8 at the quarter points and minimum distances of approximately 0.55 at the corner points.

关键词: wireless sensor network (WSN)     tunnel     monitoring     feasibility study    

Antimicrobial activity of topical agents against Propionibacterium acnes: an in vitro study of clinical

null

《医学前沿(英文)》 2016年 第10卷 第4期   页码 517-521 doi: 10.1007/s11684-016-0480-9

摘要:

This study aimed to compare the antimicrobial activities of topical agents against Propionibacterium acnes isolated from patients admitted to a hospital in Shanghai, China. The minimal inhibitory concentrations of the cultured P. acnes were determined in accordance with the Clinical and Laboratory Standards Institute. Susceptibilities to clindamycin and erythromycin were compared in terms of gender, age, disease duration, previous treatment, and disease severity. A total of 69 P. acnes strains were isolated from 98 patients (70.41%). The susceptibility to triple antibiotic ointment (neomycin/bacitracin/polymyxin B) and bacitracin was 100%. The susceptibility to fusidic acid was 92.7%. The resistance rates to neomycin sulfate, erythromycin, and clindamycin were 11.7%, 49.3%, and 33.4%, respectively. The high resistance rate to clindamycin and erythromycin was significantly affected by gender, previous treatment, and disease severity rather than by age and disease duration. Topical antibiotics should not be used separately for long-term therapy to avoid multiresistance. The use of topical antibiotics should be determined by clinicians on the basis of clinical conditions.

关键词: antimicrobial susceptibility/resistance     Propionibacterium acnes     topical antibiotics     in vitro study    

Genetic study and molecular breeding for high phosphorus use efficiency in maize

null

《农业科学与工程前沿(英文)》 2019年 第6卷 第4期   页码 366-379 doi: 10.15302/J-FASE-2019278

摘要:

Phosphorus is the second most important macronutrient after nitrogen and it has many vital functions in the life of plants. Most soils have a low available P content, which has become a key limiting factor for increasing crop production. Also, low P use efficiency (PUE) of crops in conjunction with excessive application of P fertilizers has resulted in serious environmental problems. Thus, dissecting the genetic architecture of crop PUE, mining related quantitative trait loci (QTL) and using molecular breeding methods to improve high PUE germplasm are of great significance and serve as an efficient approach for the development of sustainable agriculture. In this review, molecular and phenotypic characteristics of maize inbred lines with high PUE, related QTL and genes as well as low-P responses are summarized. Based on this, a breeding strategy applying genomic selection as the core, and integrating the existing genetic information and molecular breeding techniques is proposed for breeding high PUE maize inbred lines and hybrids.

关键词: maize     phosphorus use efficiency     quantitative trait loci     genetic study     molecular breeding     genomic selection    

Parametric study on seismic performance of self-centering reinforced concrete column with bottom-placed

《结构与土木工程前沿(英文)》   页码 1145-1162 doi: 10.1007/s11709-023-0945-2

摘要: To realize seismic-resilient reinforced concrete (RC) moment-resisting frame structures, a novel self-centering RC column with a rubber layer placed at the bottom (SRRC column) is proposed herein. For the column, the longitudinal reinforcement dissipates seismic energy, the rubber layer allows the rocking of the column, and the unbonded prestressed tendon enables self-centering capacity. A refined finite element model of the SRRC column is developed, the effectiveness of which is validated based on experimental results. Results show that the SRRC column exhibits stable energy dissipation capacity and no strength degradation; additionally, it can significantly reduce permanent residual deformation and mitigate damage to concrete. Extensive parametric studies pertaining to SRRC columns have been conducted to investigate the critical factors affecting their seismic performance.

关键词: seismic resilience     self-centering     rubber layer     flag-shaped hysteresis loop     parametric study    

Experimental study on the laminar flame speed of hydrogen/natural gas/air mixtures

Chen DONG, Qulan ZHOU, Xiaoguang ZHANG, Qinxin ZHAO, Tongmo XU, Shi’en HUI

《化学科学与工程前沿(英文)》 2010年 第4卷 第4期   页码 417-422 doi: 10.1007/s11705-010-0515-8

摘要: Laminar flame speeds of hydrogen/natural gas/air mixtures have been measured over a full range of fuel compositions (0–100% volumetric fraction of H ) and a wide range of equivalence ratio using Bunsen burner. High sensitivity scientific CCD camera is use to capture the image of laminar flame. The reaction zone area is employed to calculate the laminar flame speed. The initial temperature and pressure of fuel air mixtures are 293 K and 1 atm. The laminar flame speeds of hydrogen/air mixture and natural gas/air mixture reach their maximum values 2.933 and 0.374 m/s when equivalence ratios equal to 1.7 and 1.1, respectively. The laminar flame speeds of hydrogen/natural gas/air mixtures rise with the increase of volumetric fraction of hydrogen. Moreover, the increase in laminar flame speed as the volumetric fraction of hydrogen increases presents an exponential increasing trend versus volumetric fraction of hydrogen. Empirical formulas to calculate the laminar flame speeds of hydrogen, natural gas, and hydrogen/natural gas mixtures are also given. Using these formulas, the laminar flame speed at different hydrogen fractions and equivalence ratios can be calculated.

关键词: laminar flame speed     experimental study     Bunsen flame    

and in-hospital mortality of V-V ECMO-supported patients—the ECMO quality improvement action (EQIA) study: a national cohort study in China from 2017 to 2019

《医学前沿(英文)》 doi: 10.1007/s11684-023-1014-x

摘要: This cohort study was performed to explore the influence of intensive care unit (ICU) quality on in-hospital mortality of veno-venous (V-V) extracorporeal membrane oxygenation (ECMO)-supported patients in China. The study involved all V-V ECMO-supported patients in 318 of 1700 tertiary hospitals from 2017 to 2019, using data from the National Clinical Improvement System and China National Critical Care Quality Control Center. ICU quality was assessed by quality control indicators and capacity parameters. Among the 2563 V-V ECMO-supported patients in 318 hospitals, a significant correlation was found between ECMO-related complications and prognosis. The reintubation rate within 48 hours after extubation and the total ICU mortality rate were independent risk factors for higher in-hospital mortality of V-V ECMO-supported patients (cutoff: 1.5% and 7.0%; 95% confidence interval: 1.05–1.48 and 1.04–1.45; odds ratios: 1.25 and 1.23; P = 0.012 and P = 0.015, respectively). Meanwhile, the V-V ECMO center volume was a protective factor (cutoff of ≥ 50 cases within the 3-year study period; 95% confidence interval: 0.57–0.83, odds ratio: 0.69, P = 0.0001). The subgroup analysis of 864 patients in 11 high-volume centers further strengthened these findings. Thus, ICU quality may play an important role in improving the prognosis of V-V ECMO-supported patients.

关键词: veno-venous extracorporeal membrane oxygenation     in-hospital mortality     high-volume centers     quality control     intensive care unit capacity parameters    

Microplastics in municipal wastewater treatment plants: a case study of Denizli/Turkey

《环境科学与工程前沿(英文)》 2023年 第17卷 第8期 doi: 10.1007/s11783-023-1699-8

摘要:

● High amounts of microplastics are released to receiving media from WWTPs.

关键词: Microplastics     Wastewater treatment plant     Removal efficiency     Daily discharge    

Theoretical study on the mechanism of sulfur migration to gas in the pyrolysis of benzothiophene

《化学科学与工程前沿(英文)》 2023年 第17卷 第3期   页码 334-346 doi: 10.1007/s11705-022-2209-4

摘要: The release and control of sulfur species in the pyrolysis of fossil fuels and solid wastes have attracted attention worldwide. Particularly, thiophene derivatives are important intermediates for the sulfur gas release from organic sulfur, but the underlying migration mechanisms remain unclear. Herein, the mechanism of sulfur migration during the release of sulfur-containing radicals in benzothiophene pyrolysis was explored through quantum chemistry modeling. The C1-to-C2 H-transfer has the lowest energy barrier of 269.9 kJ·mol–1 and the highest rate constant at low temperatures, while the elevated temperature is beneficial for C−S bond homolysis. 2-Ethynylbenzenethiol is the key intermediate for the formation of S and SH radicals with the overall energy barriers of 408.0 and 498.7 kJ·mol–1 in favorable pathways. The generation of CS radicals is relatively difficult because of the high energy barrier (551.8 kJ·mol–1). However, it can be significantly promoted by high temperatures, where the rate constant exceeds that for S radical generation above 930 °C. Consequently, the strong competitiveness of S and SH radicals results in abundant H2S during benzothiophene pyrolysis, and the high temperature is more beneficial for CS2 generation from CS radicals. This study lays a foundation for elucidating sulfur migration mechanisms and furthering the development of pyrolysis techniques.

关键词: benzothiophene     sulfur migration     pyrolysis     density functional theory    

EXPLORING THE RECYCLING OF MANURE FROM URBAN LIVESTOCK FARMS: A CASE STUDY IN ETHIOPIA

《农业科学与工程前沿(英文)》 2021年 第8卷 第1期

摘要:

• Livestock manure was the main organic waste in urban and peri-urban areas.

• Manure production will increase by a factor of 3–10 between 2015–2050.

• Only 13%–38% of excreted N by livestock will be recycled in croplands.

• Intensification of urban livestock production greatly increased N surpluses.

• Reducing population growth and increasing livestock productivity needed.

 

Urban population growth is driving the expansion of urban and peri-urban agriculture (UPA) in developing countries. UPA is providing nutritious food to residents but the manures produced by UPA livestock farms and other wastes are not properly recycled. This paper explores the effects of four scenarios: (1) a reference scenario (business as usual), (2) increased urbanization, (3) UPA intensification, and (4) improved technology, on food-protein self-sufficiency, manure nitrogen (N) recycling and balances for four different zones in a small city (Jimma) in Ethiopia during the period 2015-2050. An N mass flow model with data from farm surveys, field experiments and literature was used. A field experiment was conducted and N use efficiency and N fertilizer replacement values differed among the five types of composts derived from urban livestock manures and kitchen wastes. The N use efficiency and N fertilizer replacement values were used in the N mass flow model.

Livestock manures were the main organic wastes in urban areas, although only 20 to 40% of animal-sourced food consumed was produced in UPA, and only 14 to 19% of protein intake by residents was animal-based. Scenarios indicate that manure production in UPA will increase 3 to 10 times between 2015 and 2050, depending on urbanization and UPA intensification. Only 13 to 38% of manure N will be recycled in croplands. Farm-gate N balances of UPA livestock farms will increase to>1 t·ha1 in 2050. Doubling livestock productivity and feed protein conversion to animal-sourced food will roughly halve manure N production.

Costs of waste recycling were high and indicate the need for government incentives. Results of these senarios are wake-up calls for all stakeholders and indicate alternative pathways.

A Study of the Functional Mechanism of Petrochemical Engineering Construction Project Management

Ji-ming Wang

《工程管理前沿(英文)》 2014年 第1卷 第2期   页码 129-139 doi: 10.15302/J-FEM-2014020

摘要: This paper, proceeding from the project construction process, the management mode and the implementation way, makes an in-depth study of the environmental characteristics and the managerial elements of petrochemical engineering construction project, revealing the inherent laws, establishing a theoretical model, and proposing a theory of the mechanisms of construction project management; and presents profound revelations found for construction project management in petrochemical engineering in seven aspects, which can play a guiding role in improving the managerial performance of petrochemical construction project. The theory established proposes that: The construction project management in petrochemical engineering is a complex systematic process, formed of 5 phases and 55 sub-processes of management, and exposed to many factors of influence; the environmental characteristics and managerial elements exercise positive impacts on managerial performance, but different factors have different impacts and act in different ways on managerial performance; the managerial elements of petrochemical engineering construction project are tiered, transferable, systematic and quantifiable, and the role of managerial elements in the managerial performance can be systematically integrated, quantitatively explained and transferred in a multi-level way.

关键词: petrochemical engineering     construction project     project management     functional mechanism    

标题 作者 时间 类型 操作

Scale study of sites and pavilions for World Expo 2010

ZHOU Zhuoyan, CHEN Yi

期刊论文

Practicality study on air-powered vehicle

LIU Lin, YU Xiaoli

期刊论文

Experimental study on shear behavior of prestressed reactive powder concrete I-girders

Hui ZHENG, Zhi FANG, Bin CHEN

期刊论文

A feasibility study of the measuring accuracy and capability of wireless sensor networks in tunnel monitoring

Xiaojun LI, Zhong JI, Hehua ZHU, Chen GU

期刊论文

魏明杰:聚酰胺反渗透膜渗透机制的分子模拟研究(2022年4月16日)

2022年06月09日

会议视频

Antimicrobial activity of topical agents against Propionibacterium acnes: an in vitro study of clinical

null

期刊论文

Genetic study and molecular breeding for high phosphorus use efficiency in maize

null

期刊论文

Parametric study on seismic performance of self-centering reinforced concrete column with bottom-placed

期刊论文

Experimental study on the laminar flame speed of hydrogen/natural gas/air mixtures

Chen DONG, Qulan ZHOU, Xiaoguang ZHANG, Qinxin ZHAO, Tongmo XU, Shi’en HUI

期刊论文

and in-hospital mortality of V-V ECMO-supported patients—the ECMO quality improvement action (EQIA) study: a national cohort study in China from 2017 to 2019

期刊论文

Huiling Song:Policy to Mitigate Supply Constraint of Byproduct Metals for Clean Energy Technology: A Case Study

2022年06月10日

会议视频

Microplastics in municipal wastewater treatment plants: a case study of Denizli/Turkey

期刊论文

Theoretical study on the mechanism of sulfur migration to gas in the pyrolysis of benzothiophene

期刊论文

EXPLORING THE RECYCLING OF MANURE FROM URBAN LIVESTOCK FARMS: A CASE STUDY IN ETHIOPIA

期刊论文

A Study of the Functional Mechanism of Petrochemical Engineering Construction Project Management

Ji-ming Wang

期刊论文