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Rapid control of black and odorous substances from heavily-polluted sediment by oxidation: Efficiency and effects

Kun Li, Min Yang, Jianfeng Peng, Ruiping Liu, Tista Prasai Joshi, Yaohui Bai, Huijuan Liu

《环境科学与工程前沿(英文)》 2019年 第13卷 第6期 doi: 10.1007/s11783-019-1171-y

摘要: Oxidants were proposed to rapidly control black and odorous substances in sediments. NaClO and KMnO4 had excellent efficiency to remove black and odorous substances. NaClO dramatically accelerated the release of organics, NH4+-N, P, and heavy-metals. Moderate oxidation had a limited effect on microbial communities. NaClO of 0.2 mmol/g was viewed to be the optimum option. The control of black and odorous substances in sediments is of crucial importance to improve the urban ecological landscape and to restore water environments accordingly. In this study, chemical oxidation by the oxidants NaClO, H2O2, and KMnO4 was proposed to achieve rapid control of black and odorous substances in heavily-polluted sediments. Results indicate that NaClO and KMnO4 are effective at removing Fe(II) and acid volatile sulfides. The removal efficiencies of Fe(II) and AVS were determined to be 45.2%, 94.1%, and 93.7%, 89.5% after 24-h exposure to NaClO and KMnO4 at 0.2 mmol/g, respectively. Additionally, rapid oxidation might accelerate the release of pollutants from sediment. The release of organic matters and phosphorus with the maximum ratios of 22.1% and 51.2% was observed upon NaClO oxidation at 0.4 mmol/g. Moreover, the introduction of oxidants contributed to changes in the microbial community composition in sediment. After oxidation by NaClO and KMnO4 at 0.4 mmol/g, the Shannon index decreased from 6.72 to 5.19 and 4.95, whereas the OTU numbers decreased from 2904 to 1677 and 1553, respectively. Comparatively, H2O2 showed a lower effect on the removal of black and odorous substances, pollutant release, and changes in sediment microorganisms. This study illustrates the effects of oxidant addition on the characteristics of heavily polluted sediments and shows that chemical oxidants may be an option to achieve rapid control of black and odorous substances prior to remediation of water environments.

关键词: Oxidants     Heavily polluted sediment     Black and odorous substances     Release behaviors     Microorganism    

Design of nanocarriers for efficient cellular uptake and endosomal release of small molecule and nucleic

Vaibhav Mundra, Ram I. Mahato

《化学科学与工程前沿(英文)》 2014年 第8卷 第4期   页码 387-404 doi: 10.1007/s11705-014-1457-3

摘要: There are many challenges in developing efficient and target specific delivery systems of small molecule and nucleic acid drugs. Cell membrane presents one of the major barriers for the penetration of hydrophilic macromolecules across the plasma membrane. Nanocarriers have been designed to enhance their cellular uptake via endocytosis but following their cellular uptake, endosomal escape is the rate limiting step which restricts the value associated with the enhanced uptake by nanocarriers. Viruses are an excellent model for efficient cytosolic delivery by nanocarriers. Viruses exploit intracellular cues to release the genome to cytosol. In this review, we first discuss different endocytic uptake pathways and endosomal escape mechanisms. We then summarize the existing tools for studying the intracellular trafficking of nanocarriers. Finally, we highlight the important design elements of recent virus-based nanocarriers for efficient cellular uptake and endosomal escape.

关键词: nanocarrier     cellular uptake     endosomal release     nucleic acid drug    

Semi-solid materials for controlled release drug formulation: current status and future prospects

Michelle TRAN,Chun WANG

《化学科学与工程前沿(英文)》 2014年 第8卷 第2期   页码 225-232 doi: 10.1007/s11705-014-1429-7

摘要: Semi-solid materials represent an important category of inactive ingredients (excipients) of pharmaceutical products. Here we review several common semi-solid polymers currently used in the controlled release formulations of many drugs. These polymers are selected based on their importance and broad scope of application in FDA-approved drug products and include several polysaccharides (cellulose, starch, chitosan, alginate) and carbomers, a group of mucoadhesive synthetic polymers. Glyceride-based polymers used in self-emulsifying drug delivery systems (SEDDS) will also be discussed for its importance in formulating poorly water-soluble drugs. Unique features and advantages of each type of semi-solid materials are discussed and examples of their use in oral delivery of drugs are provided. Finally, future prospects of developing new and better semi-solid excipients are discussed with the objective of facilitating clinical translation.

关键词: controlled release     drug delivery     semi-solids     polymer     excipient    

Flocculation behaviors of a novel papermaking sludge-based flocculant in practical printing and dyeing

《环境科学与工程前沿(英文)》 2021年 第15卷 第5期 doi: 10.1007/s11783-021-1390-x

摘要:

•PSBF performed better than PAC and PAM in CODCr removals.

关键词: Practical wastewater treatment     Commercial coagulant/flocculant     Secondary coagulation-flocculation process     Chemical oxygen demand     Coagulation-flocculation mechanism    

Study on the NOx release rule along the boiler during pulverized coal combustion

JIN Jing, ZHANG Zhongxiao, LI Ruiyang

《能源前沿(英文)》 2007年 第1卷 第1期   页码 91-95 doi: 10.1007/s11708-007-0009-7

摘要: Numerical simulation and experimental study on NO release along the boiler during pulverized coal combustion have been conducted. With the increase of temperature the NO emission increased and the peak value of NO release moved forward. But when the temperature increased to a certain degree, NO emission began to reduce. NO emission increased with the increase of nitrogen content of coal. The peak value of NO release moved backwards with the increase of coal rank. NO emission increased obviously with the increase of stoichiometric ratio. There existed a critical average diameter of the pulverized coal (). If "d, NO emission reduced with the decrease of pulverized coal size. If >, NO emission reduced with the increase of the pulverized coal size. The results showed that the simulation results are in agreement with the experimental results for concentration distribution of NO along the axis of the furnace.

Capacity estimation and preliminary strategy for reducing the release of dioxins in China

YU Gang, ZHANG Qing, HUANG Jun, CAI Zhenxiao, SUI Qian

《环境科学与工程前沿(英文)》 2007年 第1卷 第1期   页码 13-17 doi: 10.1007/s11783-007-0002-8

摘要: As a party of the Stockholm Convention on Persistent Organic Pollutants, China must submit its national implementation plan (NIP) for this convention. The strategy and action plan for reducing the release of dioxins in China are the most important components of the NIP. Three problems are key points for developing such strategy and action plan what are the key sources for applying the best available technology/best environmental practice (BAT/BEP) to reduce the release of dioxins? How about the capacity for reducing the dioxins release from the key sources? Where are the areas of priority for applying BAT/BEP? This paper shows the efforts towards the solution of these problems. The list of key sources covering about half of the total dioxins release was determined considering four criteria. The capacity of key sources were estimated based on the difference between the emission factor corresponding to the actual situation in 2004 and that corresponding to the scenario that all key sources have been applied BAT/BEP to reduce the dioxins release. The priority analysis using the geographical information system (GIS) tool has revealed that eastern provinces should be of high priority in the future reduction activities of dioxins release in China.

关键词: GIS     difference     capacity     scenario     implementation    

Synthesis and characterization of biocompatible polyurethanes for controlled release of hydrophobic and

Juichen YANG,Hong CHEN,Yuan YUAN,Debanjan SARKAR,Jie ZHENG

《化学科学与工程前沿(英文)》 2014年 第8卷 第4期   页码 498-510 doi: 10.1007/s11705-014-1451-9

摘要: Design of biocompatible and biodegradable polymer systems for sustained and controlled release of bioactive agents is critical for numerous biomedical applications. Here, we designed, synthesized, and characterized four polyurethane carrier systems for controlled release of model drugs. These polyurethanes are biocompatible and biodegradable because they consist of biocompatible poly(ethylene glycol) or poly(caprolactone diol) as soft segment, linear aliphatic hexamethylene diisocyanate or symmetrical aliphatic cyclic dicyclohexylmethane-4,4′-diisocyanate as hard segment, and biodegradable urethane linkage. They were characterized with Fourier transform infrared spectroscopy, atomic force microscope, and differential scanning calorimetry, whereas their degradation behaviors were investigated in both phosphate buffered saline and enzymatic solutions. By tuning polyurethane segments, different release profiles of hydrophobic and hydrophilic drugs were obtained in the absence and presence of enzymes. Such difference in release profiles was attributed to a complex interplay among structure, hydrophobicity, and degradability of polyurethanes, the size and hydrophobicity of drugs, and drug-polymer interactions. Different drug-polyurethane combinations modulated the distribution and location of the drugs in polymer matrix, thus inducing different drug release mechanisms. Our results highlight an important role of segmental structure of the polyurethane as an engineering tool to control drug release.

关键词: phase structure     degradation     polyurethanes     controlled release     drug delivery    

functional supramolecular nanoparticles based on pillar[5]arene for controlled generation, storage and release

《化学科学与工程前沿(英文)》 2023年 第17卷 第3期   页码 307-313 doi: 10.1007/s11705-022-2216-5

摘要: The storage and controlled release of singlet oxygen (1O2) have attracted increasing attention due to the wide application and microsecond lifetime of 1O2 in water. Herein we provide an integrated nanoplatform consisting of a diphenylanthracene derivative, a water-soluble pillar[5]arene and a photosensitizer tetrakis(4-hydroxyphenyl)porphyrin (TPP), that may provide the controlled generation, storage and release of singlet oxygen. We design a new diphenylanthracene derivative with two trimethylammonium bromide groups on both ends that can be well recognized by the pillar[5]arene. The formed nanocarriers can be used to load TPP through their supramolecular self-assembly. The resulting nanoparticles show good water-solubility and uniform spherical morphology. After laser irradiation (660 nm), the nanoparticles exhibit excellent ability for the generation and storage of 1O2. When the irradiated nanoparticles are heated above 80 °C, 1O2 can be released from the system. Therefore, in this paper we pioneer the use of noncovalent interaction to integrate the diphenylanthracene derivatives and photosensitizers into one functional system, which provides a new strategy for the controlled generation, storage and release of singlet oxygen. We believe this groundbreaking strategy will have a great potential in providing necessary amounts of 1O2 for the photodynamic therapy of tumors in dark.

关键词: storage and controlled release of singlet oxygen     supramolecular nanoparticles     noncovalent interactions     pillararenes     diphenylanthracene     photosensitizers    

Phosphorus release potential and pollution characteristics of sediment in downstream Nansi Lake, China

Zhijian LI, Qinyan YUE, Baoyu GAO, Yanwen WANG, Qing LIU

《环境科学与工程前沿(英文)》 2012年 第6卷 第2期   页码 162-170 doi: 10.1007/s11783-011-0313-7

摘要: The research aimed to evaluate present and potential phosphorous pollution due to high sedimentary phosphorus load and release from sediment, when external phosphorus was reduced in downstream Nansi Lake. Pollution load of the sediment and overlying water was investigated. Kinetics and isotherms of adsorption/release of sedimentary phosphorus were studied to determine equilibrium phosphate concentration (EPC ) and release potential. Kinetics of phosphorus adsorption on sediment and release from sediment were well described by both the pseudo-first-order rate equation and the pseudo-second-order rate equation, but more appropriate to the pseudo-second-order rate equation with the adsorption/release capacity more close to the measured values, suggesting that the processes were chemically rate controlled and dependent on adsorption capacity. Soluble reactive phosphorus (SRP) sorption isotherms on sediment were best fitted by the modified Langmuir model indicating a monolayer adsorption. By comparing EPC and SRP of water, the status (adsorption, releasing or in equilibrium) of sediment phosphorus could be determined. The sediments at site S1, S3, S4, S5, and S7 where the EPC s were greater than the SRPs, had a potential to release phosphorus into the water column. However, those sediments at S9, S10, and S12, where the EPC s were approximately equal to the SRPs, were in impermanent equilibrium with overlying water in status of phosphorus, the sediments can be likely to release phosphorus to the water column once the equilibrium was broken. Therefore, sedimentary phosphorus can be a secondary pollution source in downstream Nansi Lake.

关键词: Nansi Lake     sediment     phosphorus     release potential     equilibrium phosphate concentration    

Controlled drug release of 5-amino salicylic acid by poly(2-hydroxyethylmethacrylate) grafted agar

G. Usha RANI,Kartick Prasad DEY,Srijita BHARTI,Sumit MISHRA

《化学科学与工程前沿(英文)》 2014年 第8卷 第4期   页码 465-470 doi: 10.1007/s11705-014-1452-8

摘要: The utilization of poly (2-hydroxyethylmethacrylate) grafted agar (Ag-g-P(HEMA)) as a matrix for the controlled release of 5-aminosalicylic acid was investigated. Grafted copolymers of 2-hydroxyethylmethacrylate (HEMA) monomers on agar were synthesized by microwave assisted method. drug release studies were performed at pH values of 2 and 7 in order to investigate the possibility of pH triggered release for colon targeted drug delivery. Further, the percent grafting . (the time taken for release of 50% of the enclosed drug) value was studied and the results indicate that it may be possible to develop a programmable drug release matrix based on grafted polysaccharide. Ag-g-P(HEMA) appears to be a useful matrix for controlled release.

关键词: agar     controlled drug release     5-Amino salicylic acid     poly(2-hydroxyethylmethacrylate) grafted agar    

Thermal defluorination behaviors of PFOS, PFOA and PFBS during regeneration of activated carbon by molten

《环境科学与工程前沿(英文)》 2022年 第16卷 第8期 doi: 10.1007/s11783-022-1524-9

摘要:

• New method of mineralizing PFCs was proposed.

关键词: PFCs     Molten sodium hydroxide     Thermal degradation     Activated carbon regeneration    

CFD simulation of jet behaviors in a binary gas-solid fluidized bed: comparisons with experiments

Pei PEI, Guiying WU, Bangting YU, Kai ZHANG, Jianchun JIANG, Dongsheng WEN,

《化学科学与工程前沿(英文)》 2010年 第4卷 第3期   页码 242-249 doi: 10.1007/s11705-009-0277-3

摘要: Based on the experimental observation of the fluidization characteristics of solid mixtures (resin and rapeseed) with different densities and sizes, the jet behaviours of the binary system are simulated in a two-dimensional jetting fluidized bed 0.30 m in width and 2.00 m in height. A simple mathematical model, by introducing two additional force terms in both gas and particle phase momentum equations of Gidaspow’s inviscid two-fluid model, is used to explore the effects of jet gas velocity and mixture combination on the jet penetration depth in the fluidized bed with a binary system. Experimental results show that there is a fluidization velocity interval (-) for the resin-on-rapeseed (flotsam-on-jetsam) segregated bed. The simulated jet penetration depth increases with the increase of jet gas velocity and the volume fraction of the flotsam (resin), which is in fair agreement with experimental data. The above findings show that the hydrodynamic model of Brandani and Zhang (2006), by introducing the average physical properties from Goossens et al.(1971), can be used to predict the jet behaviors of a well-mixing binary system.

关键词: mathematical     two-dimensional     flotsam-on-jetsam     fluidization velocity     physical    

高速润滑脂的弹流拖动特性

杨伯原,郑培斌,苏冰,吴勇军,邓四二

《中国工程科学》 2002年 第4卷 第4期   页码 75-78

摘要:

弹流拖动特性是润滑剂的重要性能,它对滚动轴承的 动态性能有着很大的影响。阐述了用自行设计的高速润滑脂弹流拖动力试验台在充分供脂条件下对国产7007和7018润滑脂进行的拖动力测试以及试验数据的处理,并提出了可供工程上使用的这两种润滑脂的弹流拖动系数计算公式。

关键词: 弹流润滑     拖动力试验     拖动特性    

Analysis of molten metal spreading and solidification behaviors utilizing moving particle full-implicit

《能源前沿(英文)》 2021年 第15卷 第4期   页码 959-973 doi: 10.1007/s11708-021-0753-0

摘要: To retrieve the fuel debris in Fukushima Daiichi Nuclear Power Plants (1F), it is essential to infer the fuel debris distribution. In particular, the molten metal spreading behavior is one of the vital phenomena in nuclear severe accidents because it determines the initial condition for further accident scenarios such as molten core concrete interaction (MCCI). In this study, the fundamental molten metal spreading experiments were performed with different outlet diameters and sample amounts to investigate the effect of the outlet for spreading-solidification behavior. In the numerical analysis, the moving particle full-implicit method (MPFI), which is one of the particle methods, was applied to simulate the spreading experiments. In the MPFI framework, the melting-solidification model including heat transfer, radiation heat loss, phase change, and solid fraction-dependent viscosity was developed and implemented. In addition, the difference in the spreading and solidification behavior due to the outlet diameters was reproduced in the calculation. The simulation results reveal the detailed solidification procedure during the molten metal spreading. It is found that the viscosity change and the solid fraction change during the spreading are key factors for the free surface condition and solidified materials. Overall, it is suggested that the MPFI method has the potential to simulate the actual nuclear melt-down phenomena in the future.

关键词: molten metal spreading     solidification     particle method     severe accident     fuel debris     decommissioning    

Cannabidiol prevents depressive-like behaviors through the modulation of neural stem cell differentiation

《医学前沿(英文)》 2022年 第16卷 第2期   页码 227-239 doi: 10.1007/s11684-021-0896-8

摘要: Chronic stress impairs radial neural stem cell (rNSC) differentiation and adult hippocampal neurogenesis (AHN), whereas promoting AHN can increase stress resilience against depression. Therefore, investigating the mechanism of neural differentiation and AHN is of great importance for developing antidepressant drugs. The nonpsychoactive phytocannabinoid cannabidiol (CBD) has been shown to be effective against depression. However, whether CBD can modulate rNSC differentiation and hippocampal neurogenesis is unknown. Here, by using the chronic restraint stress (CRS) mouse model, we showed that hippocampal rNSCs mostly differentiated into astrocytes under stress conditions. Moreover, transcriptome analysis revealed that the FoxO signaling pathway was involved in the regulation of this process. The administration of CBD rescued depressive-like symptoms in CRS mice and prevented rNSCs overactivation and differentiation into astrocyte, which was partly mediated by the modulation of the FoxO signaling pathway. These results revealed a previously unknown neural mechanism for neural differentiation and AHN in depression and provided mechanistic insights into the antidepressive effects of CBD.

关键词: cannabidiol     depression     radial neural stem cells     neurogenesis    

标题 作者 时间 类型 操作

Rapid control of black and odorous substances from heavily-polluted sediment by oxidation: Efficiency and effects

Kun Li, Min Yang, Jianfeng Peng, Ruiping Liu, Tista Prasai Joshi, Yaohui Bai, Huijuan Liu

期刊论文

Design of nanocarriers for efficient cellular uptake and endosomal release of small molecule and nucleic

Vaibhav Mundra, Ram I. Mahato

期刊论文

Semi-solid materials for controlled release drug formulation: current status and future prospects

Michelle TRAN,Chun WANG

期刊论文

Flocculation behaviors of a novel papermaking sludge-based flocculant in practical printing and dyeing

期刊论文

Study on the NOx release rule along the boiler during pulverized coal combustion

JIN Jing, ZHANG Zhongxiao, LI Ruiyang

期刊论文

Capacity estimation and preliminary strategy for reducing the release of dioxins in China

YU Gang, ZHANG Qing, HUANG Jun, CAI Zhenxiao, SUI Qian

期刊论文

Synthesis and characterization of biocompatible polyurethanes for controlled release of hydrophobic and

Juichen YANG,Hong CHEN,Yuan YUAN,Debanjan SARKAR,Jie ZHENG

期刊论文

functional supramolecular nanoparticles based on pillar[5]arene for controlled generation, storage and release

期刊论文

Phosphorus release potential and pollution characteristics of sediment in downstream Nansi Lake, China

Zhijian LI, Qinyan YUE, Baoyu GAO, Yanwen WANG, Qing LIU

期刊论文

Controlled drug release of 5-amino salicylic acid by poly(2-hydroxyethylmethacrylate) grafted agar

G. Usha RANI,Kartick Prasad DEY,Srijita BHARTI,Sumit MISHRA

期刊论文

Thermal defluorination behaviors of PFOS, PFOA and PFBS during regeneration of activated carbon by molten

期刊论文

CFD simulation of jet behaviors in a binary gas-solid fluidized bed: comparisons with experiments

Pei PEI, Guiying WU, Bangting YU, Kai ZHANG, Jianchun JIANG, Dongsheng WEN,

期刊论文

高速润滑脂的弹流拖动特性

杨伯原,郑培斌,苏冰,吴勇军,邓四二

期刊论文

Analysis of molten metal spreading and solidification behaviors utilizing moving particle full-implicit

期刊论文

Cannabidiol prevents depressive-like behaviors through the modulation of neural stem cell differentiation

期刊论文