资源类型

期刊论文 466

会议视频 11

年份

2023 44

2022 45

2021 55

2020 24

2019 26

2018 28

2017 25

2016 18

2015 22

2014 16

2013 18

2012 15

2011 10

2010 21

2009 16

2008 12

2007 19

2006 6

2005 6

2004 6

展开 ︾

关键词

制氢 4

碳中和 3

农业科学 2

动物养殖 2

厌氧消化 2

发展趋势 2

可再生能源 2

可持续发展 2

多晶硅 2

智能制造 2

生产调度 2

质量 2

1 1

5-戊二胺 1

cyp17a1 1

ADV 1

BP算法 1

CMAQ模型 1

CO2 EOR 1

展开 ︾

检索范围：

排序： 展示方式：

The calculation of equivalence factor for ecological footprints in China: a methodological note

Moucheng LIU,Wenhua LI,Dan ZAHNG,Ning SU

《环境科学与工程前沿（英文）》 2015年 第9卷 第6期   页码 1015-1024 doi: 10.1007/s11783-014-0670-0

摘要： The Ecological Footprint (EF), a physical indicator to measure the extent of humanity’s use of natural resources, has gained much attention since it was first used by Wackernagel and Rees in 1996. In order to appraise land area types with different levels of productivity, they introduced the concept of an equivalence factor. This relates to the average primary biomass productivities of different types of land (i.e. arable land, pasture, forest, water/fishery, built-up land and fossil energy land) to the regional average primary biomass productivity of all land types in a given year. Hence, the equivalence factor is an important parameter in the EF model and it directly affects the reliability of all results. Thus, this article calculates equivalence factors on the national and provincial levels in China based on Net Primary Production (NPP) from MODIS 1 km data in 2008. Firstly, based on the Light Utility Efficiency and CASA model, the NPP of different biologically productive lands of China and of different provinces was calculated. Secondly, China’s equivalence factor for 6 land area types was calculated based on NPP: arable land and built-up land has an equivalence factor of 1.71, forest and fossil energy land has a factor of 1.41, pasture has a factor of 0.44 and water/fishery 0.35; Finally, the equivalence factor of 6 land area types in different provinces was also calculated. The NPP of each ecosystem type varies along with the equivalence factor in different provinces. However, the ranking of the equivalence factors in different provinces remain the same, with that of arable land being the largest, and the water/fishery being the smallest.

关键词： ecological footprint     equivalence factor     net primary production     biological capacity     land types    

HTML PDF 收藏

Effects of hydraulic retention time on net present value and performance in a membrane bioreactor treatingantibiotic production wastewater

Dawei Yu, Jianxing Wang, Libin Zheng, Qianwen Sui, Hui Zhong, Meixue Cheng, Yuansong Wei

《环境科学与工程前沿（英文）》 2020年 第14卷 第6期 doi: 10.1007/s11783-020-1280-7

摘要： Abstract • The membrane bioreactor cost decreased by 38.2% by decreasing HRT from 72 h to 36 h. • Capital and operation costs contributed 62.1% and 37.9% to decreased costs. • The membrane bioreactor is 32.6% cheaper than the oxidation ditch for treatment. • The effluent COD also improved from 709.93±62.75 mg/L to 280±17.32 mg/L. • Further treatment also benefited from lower pretreatment investment. A cost sensitivity analysis was performed for an industrial membrane bioreactor to quantify the effects of hydraulic retention times and related operational parameters on cost. Different hydraulic retention times (72–24 h) were subjected to a flat-sheet membrane bioreactor updated from an existing 72 h oxidation ditch treating antibiotic production wastewater. Field experimental data from the membrane bioreactor, both full-scale (500 m3/d) and pilot (1.0 m3/d), were used to calculate the net present value (NPV), incorporating both capital expenditure (CAPEX) and operating expenditure. The results showed that the tank cost was estimated above membrane cost in the membrane bioreactor. The decreased hydraulic retention time from 72 to 36 h reduced the NPV by 38.2%, where capital expenditure contributed 24.2% more than operational expenditure. Tank construction cost was decisive in determining the net present value contributed 62.1% to the capital expenditure. The membrane bioreactor has the advantage of a longer lifespan flat-sheet membrane, while flux decline was tolerable. The antibiotics decreased to 1.87±0.33 mg/L in the MBR effluent. The upgrade to the membrane bioreactor also benefited further treatments by 10.1%–44.7% lower direct investment.

关键词： Antibiotic production wastewater     Net present value     Membrane bioreactor     Hydraulic retention time     Pollutant removal    

HTML PDF 收藏

Energy budget and economic analysis in conventional and organic rice production systems and organic scenarios

Hamed MANSOORI, Parviz Rezvani MOGHADDAM, Rooholla MORADI

《能源前沿（英文）》 2012年 第6卷 第4期   页码 341-350 doi: 10.1007/s11708-012-0206-x

摘要： Compared to conventional agriculture, organic agriculture is reported to be more efficient and effective in reducing water and soil pollution, greenhouse gases (GHGs) emission and risk of human health. In additional, field management under organic condition can be useful for increasing energy efficiency. Rice is one of the important crops which are cultivated in two forms, organic and conventional, in Iran. In order to compare the energy efficiency and economic analysis of rice production in organic and conventional systems in Iran, needed information was collected by face-to-face questionnaire in 2011 and three scenarios were designed to predict the changes of energy budget and economic analysis in the transition period that included: 25%, 50% and 75% organic management in rice production. The results showed that all energy indexes were improved in organic rice production compared to conventional condition. Higher values of benefit to cost ratio, gross and net return and lower value of total cost of production were obtained from organic rice production which indicated that the organic management of farm improved economically in comparison with the conventional rice production system. The shares of direct and renewable energies were increased by approach to organic management. Increase in energy efficiency and productivity was predicted for the transition period but decrease trend in economic indexes was projected for this period in all scenarios. The main reason for decreasing economic indexes in organic scenarios was that the market price of organic rice was the same as that of conventional rice in the transition period.

关键词： energy efficiency     specific energy     net return     Cobb-Douglas function    

HTML PDF 收藏

Spatial impacts of climate factors on regional agricultural and forestry biomass resources in north-eastern province of China

Wenyan Wang, Wei Ouyang, Fanghua Hao, Yun Luan, Bo Hu

《环境科学与工程前沿（英文）》 2016年 第10卷 第4期 doi: 10.1007/s11783-016-0864-8

摘要： Dynamic analysis of biomass combined NPP modeling has been adopted. Temperature trends to warming and precipitation has periodic fluctuation. Regional distribution of agricultural and forestry biomass is mutual and divergent. Precipitation is significantly positive correlated with agricultural biomass. Temperature is negative on forestry biomass in Lesser Khingan & northern Changbai. Precipitation plays positive effect on biomass in southwestern Changbai Mountain. The dynamics of agricultural and forestry biomass are highly sensitive to climate change, particularly in high latitude regions. Heilongjiang Province was selected as research area in North-east China. We explored the trend of regional climate warming and distribution feature of biomass resources, and then analyzed on the spatial relationship between climate factors and biomass resources. Net primary productivity (NPP) is one of the key indicators of vegetation productivity, and was simulated as base data to calculate the distribution of agricultural and forestry biomass. The results show that temperatures rose by up to 0.37°C/10a from 1961 to 2013. Spatially, the variation of agricultural biomass per unit area changed from -1.93 to 5.85 t·km ·a during 2000–2013. More than 85% of farmland areas showed a positive relationship between agricultural biomass and precipitation. The results suggest that precipitation exerts an overwhelming climate influence on agricultural biomass. The mean density of forestry biomass varied from 10 to 30 t·km . Temperature had a significant negative effect on forestry biomass in Lesser Khingan and northern Changbai Mountain, because increased temperature leads to decreased Rubisco activity and increased respiration in these areas. Precipitation had a significant positive relationship with forestry biomass in south-western Changbai Mountain, because this area had a warmer climate and stress from insufficient precipitation may induce xylem cavitation. Understanding the effects of climate factors on regional biomass resources is of great significance in improving environmental management and promoting sustainable development of further biomass resource use.

关键词： Biomass resources     Net primary productivity (NPP)     Climate change     Heilongjiang Province     China     Climate     Energy systems/technology     Other sustainability (specify)     Statistical methods     GIS     Model flow     CFD    

HTML PDF 收藏

Research and industrialization of near-net rolling technology used in shaft parts

Zhenghuan HU, Baoyu WANG, Zhenhua ZHENG

《机械工程前沿（英文）》 2018年 第13卷 第1期   页码 17-24 doi: 10.1007/s11465-018-0480-3

摘要：

Shaft part rolling is an efficient and green near-net shaping technology offering many advantages, including high production efficiency, high material utilization rate, high product quality, and excellent production environment. In this paper, the features of shaft part rolling are introduced along with the working principles of two main shaft part rolling technologies, namely, cross wedge rolling (CWR) and skew rolling (SR). In relation to this technology, some R&D achievements gained by the University of Science and Technology Beijing are summarized. Finally, the latest developments in shaft part rolling are presented, including SR steel balls, precise forming of camshaft blank by CWR, SR phosphorous copper balls at room temperature, and CWR hollow axle sleeve. Although the shaft part rolling technology has been widely used in China, it only accounts for about 15% of applicable parts at present. Nevertheless, this technology has broad application prospects.

关键词： cross wedge rolling     skew rolling     near-net rolling     shaft part    

HTML PDF 收藏

Evaluation of power regeneration in primary suspension for a railway vehicle

Ruichen WANG, Zhiwei WANG

《机械工程前沿（英文）》 2020年 第15卷 第2期   页码 265-278 doi: 10.1007/s11465-019-0571-9

摘要： To improve the fuel economy of rail vehicles, this study presents the feasibility of using power regenerating dampers (PRDs) in the primary suspension systems of railway vehicles and evaluates the potential and recoverable power that can be obtained. PRDs are configured as hydraulic electromagnetic-based railway primary vertical dampers and evaluated in parallel and series modes (with and without a viscous damper). Hydraulic configuration converts the linear behavior of the track into a unidirectional rotation of the generator, and the electromagnetic configuration provides a controllable damping force to the primary suspension system. In several case studies, generic railway vehicle primary suspension systems that are configured to include a PRD in the two configuration modes are modeled using computer simulations. The simulations are performed on measured tracks with typical irregularities for a generic UK passenger route. The performance of the modified vehicle is evaluated with respect to key performance indicators, including regenerated power, ride comfort, and running safety. Results indicate that PRDs can simultaneously replace conventional primary vertical dampers, regenerate power, and exhibit desirable dynamic performance. A peak power efficiency of 79.87% is theoretically obtained in series mode on a top-quality German Intercity Express track (Track 270) at a vehicle speed of 160 mile/h (~257 km/h).

关键词： railway vehicle     primary damper     power regeneration     ride comfort     running safety    

HTML PDF 收藏

Dynein axonemal heavy chain 10 deficiency causes primary ciliary dyskinesia in humans and mice

《医学前沿（英文）》   页码 957-971 doi: 10.1007/s11684-023-0988-8

摘要： Primary ciliary dyskinesia (PCD) is a congenital, motile ciliopathy with pleiotropic symptoms. Although nearly 50 causative genes have been identified, they only account for approximately 70% of definitive PCD cases. Dynein axonemal heavy chain 10 (DNAH10) encodes a subunit of the inner arm dynein heavy chain in motile cilia and sperm flagella. Based on the common axoneme structure of motile cilia and sperm flagella, DNAH10 variants are likely to cause PCD. Using exome sequencing, we identified a novel DNAH10 homozygous variant (c.589C > T, p.R197W) in a patient with PCD from a consanguineous family. The patient manifested sinusitis, bronchiectasis, situs inversus, and asthenoteratozoospermia. Immunostaining analysis showed the absence of DNAH10 and DNALI1 in the respiratory cilia, and transmission electron microscopy revealed strikingly disordered axoneme 9+2 architecture and inner dynein arm defects in the respiratory cilia and sperm flagella. Subsequently, animal models of Dnah10-knockin mice harboring missense variants and Dnah10-knockout mice recapitulated the phenotypes of PCD, including chronic respiratory infection, male infertility, and hydrocephalus. To the best of our knowledge, this study is the first to report DNAH10 deficiency related to PCD in human and mouse models, which suggests that DNAH10 recessive mutation is causative of PCD.

关键词： DNAH10     mice     motile cilia     mutation     primary ciliary dyskinesia    

HTML PDF 收藏

Approach for natural gas to be a primary energy source in China

Weihe HUANG, Jindian CHEN, Chuan FU, Yan HUANG

《工程管理前沿（英文）》 2019年 第6卷 第4期   页码 467-476 doi: 10.1007/s42524-019-0068-6

摘要： This work reveals the positioning of natural gas in the evolution of world energy and the general law of its development. In the long-term adjustment of energy structure, natural gas has gradually become the primary energy source because of five factors: policy, resources, technology, facilities, and market. To expedite the revolution of energy production and consumption, China must urgently expand the use of natural gas toward a more positive role in complementing coal and renewable energy and prioritize its usage in three areas, namely, urban gas, power generation, and industrial fuel. Natural gas is expected to account for approximately 15% of China’s total energy consumption in the future. For natural gas to be the primary energy, the exploitation of gas resources must be expanded, resource access must be improved, a flexible trade system must be set up, infrastructure investment must be increased, and the security system must be enhanced.

关键词： natural gas     energy revolution     primary energy     utilization areas     approaching means    

HTML PDF 收藏

Effect of traditional Chinese medicine combined with Western therapy on primary hepatic carcinoma: a

null

《医学前沿（英文）》 2017年 第11卷 第2期   页码 191-202 doi: 10.1007/s11684-017-0512-0

摘要：

Primary hepatic carcinoma (PHC) is a common malignant tumor in China. Cancer is comprehensively treated with various therapeutic regimes, including traditional Chinese medicine (TCM). TCM has been widely used to improve the quality of life, delay the time of cancer progression, and prolong the median survival time. This systematic review with meta-analysis aimed to assess the effect of TCM combined with Western therapy on primary hepatic carcinoma. A comprehensive literature search was conducted in six databases, including CNKI, VIP, Wan-Fang Database, CBM, PubMed, and Cochrane library. A total of 44 randomized controlled trials (RCTs) involving 3429 participants suffering from PHC were selected. Meta-analysis results indicated that the overall effect of TCM and Western integrative treatment on PHC was higher than that of Western intervention alone, which can postpone tumor recurrence and metastasis and prolong the overall survival time of patients with PHC. Although the obtained evidence remained weak because of the poor methodological quality of the included studies, this review provided relevant data supporting the efficacy and safety of TCM combined with Western therapies. In future research, individual RCT studies should incorporate accepted standards for trial design and reporting, proper outcome indicators according to international standards, blinding in allocation concealment, and valid follow-up periods.

关键词： traditional Chinese medicine     primary hepatic carcinoma     meta-analysis    

HTML PDF 收藏

Tuning the primary selective nanochannels of MOF thin-film nanocomposite nanofiltration membranes for

《环境科学与工程前沿（英文）》 2022年 第16卷 第4期 doi: 10.1007/s11783-021-1474-7

摘要：

• PA layer properties tune the primary nanochannels in MIL-101(Cr) TFN NF membranes.

关键词： Porous metal organic framework     Thin-film nanocomposite membrane     Primary selective nanochannels     Nanofiltration     Endocrine disrupting compounds    

HTML PDF 收藏

Primary hypertrophic osteoarthropathy: an update

null

《医学前沿（英文）》 2013年 第7卷 第1期   页码 60-64 doi: 10.1007/s11684-013-0246-6

摘要：

Digital clubbing, which has been recognized as a sign of systemic disease, is one of the most ancient diseases. However, the pathogenesis of clubbing and hypertrophic osteoarthropathy has hitherto been poorly understood. The study of a clinically indistinguishable idiopathic form (primary hypertrophic osteoarthropathy, PHO) provides an opportunity to understand the pathogenesis of hypertrophic osteoarthropathy. Current advances in the study of PHO are discussed. The impaired metabolism of prostaglandin E2 (PGE2) plays a central role in its pathogenesis.

关键词： digital clubbing     primary hypertrophic osteoarthropathy     prostaglandin E2 (PGE2)    

HTML PDF 收藏

华北地区生态保护与恢复的水资源效应研究

孙思琦,陈永喆,王聪,胡庆芳,吕一河

《中国工程科学》 2022年 第24卷 第5期   页码 97-106 doi: 10.15302/J-SSCAE-2022.05.012

摘要：

近年来，华北地区实施了一系列生态保护与恢复工程，植被生态状况发生了显著变化；探究区域植被恢复对水循环过程及水资源供需平衡的影响，对于完善生态恢复策略、实现区域水资源可持续利用十分重要。本文采用皮尔逊相关系数和莫兰指数，结合多源水参量数据进行综合性分析，阐释了植被和不同水参量的时空变化情况，甄别了植被保育与恢复下的水资源变化响应，进而探讨了华北地区水资源与植被恢复的权衡关系。研究结果表明，华北地区的生态保护与恢复工程成效显著，植被净初级生产力的增速约为恢复工程区外的2.3 倍；植被的扩张与蒸散量表现出空间与时间上的强相关性；植被恢复引起的蒸散量提高是引起水储量赤字或显著降低的主要原因。为此建议，华北地区可完善生态恢复策略，在植被保育与恢复过程中考虑水资源的限制作用；以自然恢复方式为主，促进生态恢复的可持续性、水资源的可利用性。

关键词： 华北地区；生态恢复工程；蒸散发；水储量；植被净初级生产力；自然恢复    

HTML PDF 收藏

Case report of neurofibromatosis type 1 combined with primary ciliary dyskinesia

《医学前沿（英文）》 2021年 第15卷 第6期   页码 933-937 doi: 10.1007/s11684-021-0860-7

摘要： Neurofibromatosis (NF) is a genetic disease in which the lungs are rarely involved. However, in NF cases with lung involvement, chest computed tomography may show bilateral basal reticulations, apical bullae, and cysts without bronchiectasis. Herein, we report a patient diagnosed with NF on the basis of the results of genetic testing who presented with early-onset wet cough and bronchiectasis. Considering the differential diagnosis of bronchiectasis combined with his early-onset wet cough, sinusitis, and sperm quality decline, we considered the possibility of primary ciliary dyskinesia (PCD). Further electron microscopy analysis of cilia and identification of homozygous mutations in the RSPH4A gene confirmed the diagnosis of PCD. Therefore, for patients with NF, when an image change exists in the lungs that does not correspond to NF, the possibility of other diagnoses, including PCD, must be considered.

关键词： primary ciliary dyskinesia     neurofibromatosis     bronchiectasis     transmission electron microscopy     genetic sequencing    

HTML PDF 收藏

Diagnostic evaluation of plasma aldosterone concentration to plasma renin activity ratio in primary aldosteronism

ZHANG Huilan, WANG Daowen

《医学前沿（英文）》 2008年 第2卷 第1期   页码 11-14 doi: 10.1007/s11684-008-0003-4

摘要： Using the plasma aldosterone concentration to plasma renin activity ratio (PAC/PRA ratio) as the screening test of choice for primary aldosteronism in hypertensive patients, we studied the clinical characteristics and the diagnostic value of PAC/PRA ratio in primary aldosteronism. The plasma aldosterone concentration (PAC) and plasma renin activity (PRA) levels were measured by radioimmunoassay in 902 hypertensive patients from out-patient clinics or hospitals. One hundred and twenty-six suspected primary aldosteronism patients whose PAC/PRA ratio was > 25 ng/dL/ng/mL/hr had a lamellar computed tomography (CT) scan in the adrenal gland and follow-up visits. The proportion of primary aldosteronism in hypertensive patients was 14% (126/902). There were 54 patients with unilateral or bilateral hyperplasia and 25 patients with adenoma according to the CT scan. 39% (49/126) of the patients with primary aldosteronism had hypokalemia. Twenty-five patients received surgical treatment. The efficacy and cure rates were 100% (25/25) and 48% (12/25), respectively. The effective rate of aldactone and the single-drug cure rate were 89% (48/54) and 24% (13/54), respectively. Primary aldosteronism affects over 10% of hypertensive patients in China. The PAC/PRA ratio can be considered as a routine screening test in hypertensives, especially resistant hypertensive patients and a high PAC/PRA ratio is an invaluable index in primary aldosteronism diagnosis.
HTML PDF 收藏

标题 作者 时间 类型 操作

The calculation of equivalence factor for ecological footprints in China: a methodological note

Moucheng LIU,Wenhua LI,Dan ZAHNG,Ning SU

期刊论文

Effects of hydraulic retention time on net present value and performance in a membrane bioreactor treatingantibiotic production wastewater

Dawei Yu, Jianxing Wang, Libin Zheng, Qianwen Sui, Hui Zhong, Meixue Cheng, Yuansong Wei

期刊论文

Energy budget and economic analysis in conventional and organic rice production systems and organic scenarios

Hamed MANSOORI, Parviz Rezvani MOGHADDAM, Rooholla MORADI

期刊论文

逯高清：Green Hydrogen Production and Storage Towards a Net-Zero Carbon Future（2021年5月21日）

2021年10月13日

会议视频

Spatial impacts of climate factors on regional agricultural and forestry biomass resources in north-eastern province of China

Wenyan Wang, Wei Ouyang, Fanghua Hao, Yun Luan, Bo Hu

期刊论文

Research and industrialization of near-net rolling technology used in shaft parts

Zhenghuan HU, Baoyu WANG, Zhenhua ZHENG

期刊论文

Evaluation of power regeneration in primary suspension for a railway vehicle

Ruichen WANG, Zhiwei WANG

期刊论文

Dynein axonemal heavy chain 10 deficiency causes primary ciliary dyskinesia in humans and mice

期刊论文

Approach for natural gas to be a primary energy source in China

Weihe HUANG, Jindian CHEN, Chuan FU, Yan HUANG

期刊论文

Effect of traditional Chinese medicine combined with Western therapy on primary hepatic carcinoma: a

null

期刊论文

Tuning the primary selective nanochannels of MOF thin-film nanocomposite nanofiltration membranes for

期刊论文

Primary hypertrophic osteoarthropathy: an update

null

期刊论文

华北地区生态保护与恢复的水资源效应研究

孙思琦,陈永喆,王聪,胡庆芳,吕一河

期刊论文

Case report of neurofibromatosis type 1 combined with primary ciliary dyskinesia

期刊论文

Diagnostic evaluation of plasma aldosterone concentration to plasma renin activity ratio in primary aldosteronism

ZHANG Huilan, WANG Daowen

期刊论文