资源类型

期刊论文 11

年份

2022 1

2019 2

2018 2

2017 4

2015 1

2014 1

关键词

检索范围:

排序: 展示方式:

Integration of renewable energies, flexible loads and storages into the German power grid: Actual situationin German change of power system

Harald SCHWARZ, Xiaoshu CAI

《能源前沿(英文)》 2017年 第11卷 第2期   页码 107-118 doi: 10.1007/s11708-017-0470-x

摘要: Starting from the late 1990’s, the German government decided to change the national electric power supply system dramatically. The main stimulating instrument was the German Law on Renewable Energies (Erneuerbare Energien Gesetz (EEG)), which guaranteed a fixed feed-in tariff to everyone who was willing to invest into renewable generation. Based on the year of commissioning, defined revenues per kWh were fixed for the next 20 years. Due to a very attractive over-funding, more than 1.5 million renewable generation units were connected to the German grid up to the end of 2015. According to the EEG, renewable generation units can feed to the grid wherever they are located and whenever they are able to produce. The old physical principle was and is still neglected, which clearly stated that generation always has to follow the demand—simply due to the limited availability of storages in the power system. Only in cases, when temporarily renewable overproduction exceeds the tolerable loading of lines or transformers respectively endangers the system stability in total, are German grid operators allowed to announce curtailments by emergency measures. Even in such cases, the “not produced energy” from renewable sources has to be funded. Although the installed capacity from renewables is much higher than the peak load in Germany, it contributes only about 32% to German average annual energy. Unfortunately, the regional distribution of renewable generation and load is very different, e.g. in the northeast of Germany, this Renewable Energy (RE)-ratio meanwhile exceeds 100% due to the high RE-penetration and low load. High transits of renewable overproduction from the north to the south will be necessary at nearly every day per year. Therefore, a tremendous change is needed within the German power grid. This paper will give a first overview followed by several others, describing possible solutions on how to overcome this critical situation.

关键词: grid integration     renewable energies     system stability     storages     flexible loads     new market design    

Adaptation of Chinese and German maize-based food-feed-energy systems to limited phosphate resources—anew Sino-German international research training group

null

《农业科学与工程前沿(英文)》 2019年 第6卷 第4期   页码 313-320 doi: 10.15302/J-FASE-2019282

摘要:

Phosphate is supplied to agriculture by mining and fertilizer production, followed by different steps of phosphate utilization, including primary production, feed and food consumption, and conversion of biomass, with accumulation in soils, but little recycling and severe environmental losses. Phosphate is a limited essential nutrient, however, with very uneven distribution worldwide. Closing the cycle and reducing primary phosphate consumption are fundamental future challenges. Maize has a relatively high phosphate requirement. China and Germany together cover the whole range of maize production systems. The new Sino-German international research training group “Adaptation of Chinese and German maize-based food-feed-energy systems to limited phosphate resources” (AMAIZE-P) was initiated in 2018 as a joint venture of the China Agricultural University (Beijing, China) and the University of Hohenheim (Stuttgart, Germany). The interdisciplinary and complementary research is driven by the hypothesis that under phosphate limited conditions, high productivity and high phosphate use efficiency can be achieved simultaneously by adapting phosphate cycling and availability (sources) to the multipurpose phosphate demands (sinks) in maize-based food-feed-energy systems. The educational program for doctoral researchers in China and Germany includes joint block seminars, thematic field trips, case studies, methodological courses, doctoral researchers’ conferences, intercultural training sessions and personal training.

关键词: international research training group     limited resources     maize     phosphate    

The advances of Sino-German new materials

Rongbiao Wang

《化学科学与工程前沿(英文)》 2018年 第12卷 第3期   页码 327-328 doi: 10.1007/s11705-018-1748-1

摘要:

关键词: valign=     top     class=     J_zhaiyao    

The German Energiewende and its roll-out of renewable energies: An economic perspective

Sebastian KREUZ, Felix MÜSGENS

《能源前沿(英文)》 2017年 第11卷 第2期   页码 126-134 doi: 10.1007/s11708-017-0467-5

摘要: This paper gives a short overview of the German Energiewende, i.e. the transition of a large and mostly thermal electricity system towards electricity generation from renewable energy source. It discusses both, the motivation of the transitions as future goals and current status. Furthermore, it gives an in-depth view into the changes in economic costs for society as well as electricity price effects, especially for average private households and industrial consumers. It also discusses the benefits of the promotion of renewable energies in Germany.

关键词: electricity system     renewable energy     cost-benefit analysis    

Sclerosing cholangitis in critically ill patients: an important and easily ignored problem based on a German

null

《医学前沿(英文)》 2014年 第8卷 第1期   页码 118-126 doi: 10.1007/s11684-014-0306-6

摘要:

Intensive care unit (ICU) is important in the rehabilitation of critically ill patients. In the past decades, many patients who received aggressive treatment in ICU developed sclerosing cholangitis in multiple centers. Sclerosing cholangitis in critically ill patients (SC-CIP) is a relatively new issue. To investigate the causes, clinical manifestation, treatment, and prognosis of SC-CIP, we searched for published cases in the databases of PubMed, Highwire, and Elsevier from 2001 to 2012. Data were extracted using a standard form and retrospectively analyzed. Twelve eligible studies covering 88 patients, with 64 men and 24 women, were enrolled in this analysis. The mean age was 49.8 years. All of the patients recovered from critical illnesses, such as trauma, infection, burn, and major surgeries. High pressure positive end-expiratory pressure (PEEP, peak level at 12.8 cm H2O) was utilized for all patients, with the average duration of 36.3 d. In addition, vasopressor agents were administered in approximately 60% of SC-CIP. A rapid increase in cholestasis and irregular strictures in the intrahepatic bile ducts was observed in the following months. With an average follow-up period of 17.9 months, poor outcomes were observed in 54 patients, including 34 deaths. In conclusion, ischemic injury of the biliary tree, which may be affected by PEEP and/or vasopressor administration, affects cholangiopathic procedure. As a newly discovered type of secondary sclerosing cholangitis, SC-CIP is a severe progressive complication of patients in ICU and should be carefully monitored by clinicians.

关键词: intensive care unit     sclerosing cholangitis     ischemic injury     prognosis     systemic review    

Possible role of power-to-vehicle and vehicle-to-grid as storages and flexible loads in the German 110

Erik BLASIUS

《能源前沿(英文)》 2017年 第11卷 第2期   页码 146-154 doi: 10.1007/s11708-017-0475-5

摘要: The sectoral coupling of road traffic (in form of E-Mobility) and electrical energy supply (known as power-to-vehicle (P2V), vehicle-to-grid (V2G) is discussed as one of the possible development concepts for the flexible system integration of renewable energy sources (RES) and the support of the objectives of the German energy transition (aka. Energiewende). It is obvious that E-mobility, which shall produce as few emissions as possible, should be based on the exclusive use of renewable energies. At the same time, the E-mobility can help to reduce the negative effects of the grid integration of RES to the distribution grids. However, this assumes that the electric vehicles are smart integrated to the grids where they charge, meaning that they must be able to communicate and be controllable. Because per se unplanned and uncontrollable charging processes are harmful for the grid operation, especially if they occur frequently and unexpected in similar time periods, the effects can hardly be controlled and can lead to serious technical problems in practical grid operation. This paper provides an insight into the current development of E-mobility in Germany. The insight will be matched with the German development of the RES. By the combination of both sectors, the possible role of the E-mobility for the distribution grid will be depicted, which can have positive and negative aspects.

关键词: P2V     V2G     grid integration     electric vehicles     distribution grid    

Generating native user interfaces formultiple devices by means ofmodel transformation

Ignacio MARIN,Francisco ORTIN,German PEDROSA,Javier RODRIGUEZ

《信息与电子工程前沿(英文)》 2015年 第16卷 第12期   页码 995-1017 doi: 10.1631/FITEE.1500083

摘要: In the last years, the types of devices used to access information systems have notably increased using different operating systems, screen sizes, interaction mechanisms, and software features. This device fragmentation is an important issue to tackle when developing native mobile service front-end applications. To address this issue, we propose the generation of native user interfaces (UIs) by means of model transformations, following the modelbased user interface (MBUI) paradigm. The resulting MBUI framework, called LIZARD, generates applications for multiple target platforms. LIZARD allows the definition of applications at a high level of abstraction, and applies model transformations to generate the target native UI considering the specific features of target platforms. The generated applications follow the UI design guidelines and the architectural and design patterns specified by the corresponding operating system manufacturer. The objective is not to generate generic applications following the lowest-common-denominator approach, but to follow the particular guidelines specified for each target device. We present an example application modeled in LIZARD, generating different UIs for Windows Phone and two types of Android devices (smartphones and tablets).

关键词: Model-to-model transformation     Native user interfaces     Model-based user interfaces     Model-driven engineering    

Possible role of power-to-heat and power-to-gas as flexible loads in German medium voltage networks

Mark KUPRAT, Martin BENDIG, Klaus PFEIFFER

《能源前沿(英文)》 2017年 第11卷 第2期   页码 135-145 doi: 10.1007/s11708-017-0472-8

摘要: Germany’s energy transition triggered a rapid and unilateral growth of renewable energy sources (RES) in the electricity sector. With increasing shares of intermittent RES, overcapacities during periods of strong wind and photovoltaic electricity generation occur. In the face of insufficient transmission capacities, due to an inhibited network extension, the electricity generation has to be curtailed. This curtailment of RES leads to economic losses and could be avoided through flexible loads. As an option to cope with those problems, the technologies of power-to-gas (PtG) and power-to-heat (PtH) are presented in this paper. First, the alkaline electrolyzer (AEL), polymer electrolyte membrane electrolyzer (PEMEL), and solid oxide electrolyzer cell (SOEC) are investigated regarding their operational parameters. Second, the electric boiler, electrode heating boiler, and heat pumps are considered. Ultimately, the network-supporting abilities and the potential to provide ancillary services, such as control power, load sequence operation, cold start and part load capability, are compared among one another.

关键词: power-to-gas     power-to-heat     flexible loads     ancillary services     coherent energy systems    

Suitability of common models to estimate hydrology and diffuse water pollution in North-eastern German

Muhammad WASEEM, Frauke KACHHOLZ, Jens TRÄNCKNER

《农业科学与工程前沿(英文)》 2018年 第5卷 第4期   页码 420-431 doi: 10.15302/J-FASE-2018243

摘要:

Various process-based models are extensively being used to analyze and forecast catchment hydrology and water quality. However, it is always important to select the appropriate hydrological and water quality modeling tools to predict and analyze the watershed and also consider their strengths and weaknesses. Different factors such as data availability, hydrological, hydraulic, and water quality processes and their desired level of complexity are crucial for selecting a plausible modeling tool. This review is focused on suitable model selection with a focus on desired hydrological, hydraulic and water quality processes (nitrogen fate and transport in surface, subsurface and groundwater bodies) by keeping in view the typical lowland catchments with intensive agricultural land use, higher groundwater tables, and decreased retention times due to the provision of artificial drainage. In this study, four different physically based, partially and fully distributed integrated water modeling tools, SWAT (soil and water assessment tool), SWIM (soil and water integrated model), HSPF (hydrological simulation program– FORTRAN) and a combination of tools from DHI (MIKE SHE coupled with MIKE 11 and ECO Lab), have been reviewed particularly for the Tollense River catchment located in North-eastern Germany. DHI combined tools and SWAT were more suitable for simulating the desired hydrological processes, but in the case of river hydraulics and water quality, the DHI family of tools has an edge due to their integrated coupling between MIKE SHE, MIKE 11 and ECO Lab. In case of SWAT, it needs to be coupled with another tool to model the hydraulics in the Tollense River as SWAT does not include backwater effects and provision of control structures. However, both SWAT and DHI tools are more data demanding in comparison to SWIM and HSPF. For studying nitrogen fate and transport in unsaturated, saturated, and river zone, HSPF was a better model to simulate the desired nitrogen transformation and transport processes. However, for nitrogen dynamics and transformations in shallow streams, ECO Lab had an edge due its flexibility for inclusion of user-desired water quality parameters and processes. In the case of SWIM, most of the input data and governing equations are similar to SWAT but it does not include water bodies (ponds and lakes), wetlands and drainage systems. In this review, only the processes that were needed to simulate the Tollense River catchment were considered, however the resulted model selection criteria can be generalized to other lowland catchments in Australia, North-western Europe and North America with similar complexity.

关键词: diffuse pollution     ECO Lab     HSPF     lowland catchment     MIKE 11     MIKE SHE     modeling tools     SWAT     SWIM     Tollense River     water quality    

Key stakeholders’ perspectives on the ideal partnering culture in construction projects

Gunnar J. LÜHR, Marian G. C. BOSCH-REKVELDT, Mladen RADUJKOVIC

《工程管理前沿(英文)》 2022年 第9卷 第2期   页码 312-325 doi: 10.1007/s42524-020-0135-z

摘要: This paper examines the current state of project cultures in the German turnkey construction industry and the ideal project cultures in terms of partnering from the perspective of various key stakeholders (i.e., Investors, General Contractors, (Sub-)Contractors and Designers). To investigate the current and ideal cultures, data were gathered among the key stakeholders by means of a survey study with 72 respondents divided over 12 companies. The respondents rated the current and desired cultures by using the Organizational Culture Assessment Instrument, which belongs to the Competing Values Framework. The investigations show many similarities and differences between the stakeholder perspectives of the current and the idealized partnering project cultures. Mainly, the General Contractors desire more cooperative behaviors than the (Sub-)Contractors, and the Investors desire more pronounced flexibility than the General Contractors. All stakeholders desire a cultural change from highly competitive behaviors toward more cooperation. Changes in terms of clear procedures or more flexibility are only desired by the Designers. Defining both the current and an ideal partnering project culture enables academics and project managers to compare their actual project cultures to an ideal situation. With such an approach, academics and project managers could measure whether new tools or changes in resources affect their project cultures toward a partnering project culture.

关键词: project culture     organisational culture     partnering     construction culture     stakeholder perspectives     German    

标题 作者 时间 类型 操作

Integration of renewable energies, flexible loads and storages into the German power grid: Actual situationin German change of power system

Harald SCHWARZ, Xiaoshu CAI

期刊论文

Comments on “Adaptation of Chinese and German maize-based food-feed-energy systems to limited phosphateresources—a new Sino-German international research training group”

null

期刊论文

Adaptation of Chinese and German maize-based food-feed-energy systems to limited phosphate resources—anew Sino-German international research training group

null

期刊论文

The advances of Sino-German new materials

Rongbiao Wang

期刊论文

The German Energiewende and its roll-out of renewable energies: An economic perspective

Sebastian KREUZ, Felix MÜSGENS

期刊论文

Sclerosing cholangitis in critically ill patients: an important and easily ignored problem based on a German

null

期刊论文

Possible role of power-to-vehicle and vehicle-to-grid as storages and flexible loads in the German 110

Erik BLASIUS

期刊论文

Generating native user interfaces formultiple devices by means ofmodel transformation

Ignacio MARIN,Francisco ORTIN,German PEDROSA,Javier RODRIGUEZ

期刊论文

Possible role of power-to-heat and power-to-gas as flexible loads in German medium voltage networks

Mark KUPRAT, Martin BENDIG, Klaus PFEIFFER

期刊论文

Suitability of common models to estimate hydrology and diffuse water pollution in North-eastern German

Muhammad WASEEM, Frauke KACHHOLZ, Jens TRÄNCKNER

期刊论文

Key stakeholders’ perspectives on the ideal partnering culture in construction projects

Gunnar J. LÜHR, Marian G. C. BOSCH-REKVELDT, Mladen RADUJKOVIC

期刊论文