Wyniki wyszukiwania - Biblioteka Nauki

1

Study of Extraction of Cinnamon Oils from the Bark of Cinnamomum cassia presl by Supercritical Carbon Dioxide

100%

Zhao S. , Liang H.

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2006

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tom Vol. 80, nr 1

99-105

EN

Cinnamon oils were isolated from the bark of Cinnamomum cassia presl by supercritical fluid extraction (SFE) and compared with steam distillation (SD). The extracts were analyzed with GC-MS. The yield from SFE was around four times as that from SD. The results from GC-MS revealed that the constituent components obtained from SFE and SD are similar while the distributions of individual compounds are different. In SFE, effects of various factors such as time (t), extraction pressure (P), extraction temperature (T), particle size (S) and flow rate of supercritical carbon dioxide (F) on the yield of target components were investigated. Favorable operation conditions were found at t = 2 h, P = 22.5 MPa, T = 50°C, S < 0.3 mm and F = 9.0 1/h.

2

Heat transfer in thin porous fibrous material: mathematical modelling and experimental validation using active thermography

80%

Banerjee D. , Zhao S. , Schabel S.

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tom Vol. 10, no. 4

95--99

EN

This paper deals with the modelling of the heat transfer process in a thin porous fibrous material such as a paper sheet when it is subjected to an incident heat flux introduced by a laser beam. A mathematical model based on the control volume principle is developed for numerical estimation of radial temperature distribution which is validated experimentally by infrared thermography. Here the heat flux is introduced by a CO2 laser beam of 10.6 μm wavelength and an infrared image sequence is recorded as a function of time with a high resolution infrared camera. The preliminary validation results indicate that the simulation model can predict the transient development of sheet temperature very accurately under the specified heating conditions. The model can enhance our understanding and insights of the heat transfer process in such media, which is of great interest for many drying and thermal applications. Though the application shown here is on a 0.1 mm thick paper sheet, the model can be extended to any thin porous fibrous media such as textiles and nonwovens.

3

Relationship Between Bake Hardening, Snoek-Köster and Dislocation-Enhanced Snoek Peaks in Coarse Grained Low Carbon Steel

80%

Lin W. , Zhao S. , Zhang H. , Jin X.

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tom Vol. 61, iss. 3

1723--1732

EN

In the present work, specimens prepared from coarse grained low carbon steel with different prestrains were baked and then, their bake hardening (BH) property and internal friction were determined. TEM was used to characterize the dislocation structure in BH treated samples. The measurements of internal friction in prestrained samples and baked samples were carried out using a multifunctional internal friction apparatus. The results indicate that, in coarse grained low carbon steel, the bake hardening properties (BH values) were negative, which were increased by increasing the prestrain from 2 to 5%, and then were decreased by increasing the prestrain from 5 to 10%. In the specimen with prestrain 5%, the BH value reached the maximum value and the height of Snoek-Köster peak was observed to be the maximum alike. With increasing the prestrain, both of the BH value and Snoek-Köster peak heights are similarly varied. It is concluded that Snoek-Köster and dislocation-enhanced Snoek peaks, caused by the interactions between interstitial solute carbon atoms and dislocations, can be used in further development of the bake hardening steels.

4

A Risk Assessment Model of Flood Based on Information Diffusion Method and BP Neural Network

80%

Chen J. , Jin Q. , Wang H. , Zhao S.

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tom R. 88, nr 9b

33-36

EN

Climate change has caused more frequent floods in China which have already resulted in huge losses. Thus flood risk assessment and management is an important research topic. In this paper, a new model of flood risk assessment is proposed based on the information diffusion theory and the back propagation (BP) neural network. Due to the fact that flood statistics data are relatively short and often insufficient for flood risk assessment, the information diffusion method can transform imperfect flood historical data from a point in a traditional data sample to a fuzzy data set and obtain optimized data sample. Then, the optimized data are used to train neural networks with back propagation and can improve neural network adaptive ability. The flood data of Dongting Lake’s different encirclement dikes are used to assess the flood risk of Dongting Lake with the proposed model in this research. The results are consistent with the actual situation of Dongting Lake area, which thus verifies the model’s effectiveness for flood risk management. This method can be easily applied to effectively resolve problems of insufficient samples in flood risk assessment.

PL

W artykule zaprezentowano nowy model oceny ryzyka powodzi bazujący na teorii dyfuzji informacji I wykorzystujący sieci neuronowe. Dane statystyczne o powodziach są relatywnie krótkie i często niewystarczające do oceny ryzyka. W pierwszym etapie przetwarza się dane historyczne do otrzymania bardziej kompletnych danych. Te dane wykorzystane są do trenowania sieci neuronowych.

5

Smarter way to build: volumetric modular construction system

80%

Wozniak-Szpakiewicz E. , Zhao S. , Chen T.

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tom nr 25

73--80

EN

The article deals with the problem of increasing demand for modular buildings as an answer to the construction industry’s current situation and challenges of build environment. The case studies refer to the hospitality and student living sector. The author addresses the following question regarding the near future of the modular construction industry: How would it reflect on urban space, living space and the whole attitude toward modular construction issues? What is the role of the architect during the design-build process? Is it possible to make references to “beauty” in a modular construction context?

PL

Artykuł podejmuje problematykę rosnącego popytu i zapotrzebowania na realizację obiektów w oparciu o wolumetryczną technologię modułową jako odpowiedź na potrzeby zrównoważonego rozwoju. Jako przykłady wskazuje autor wskazuje obiekty hotelowe i obiekty zamieszkania studenckiego. Autor stawia pytanie o przyszłość budownictwa modułowego. Jaki wpływ będzie ono miało na kształtowanie przestrzeni miejskiej i na przestrzeń życiową? Jaka jest rola architekta podczas procesu zaprojektuj-wybuduj? Czy możliwe jest odniesienie wartości „piękna” do rozwiązań w systemie modułowym?

6

Age and Climate Sensitivity of Radial Growth of Picea crassifolia to Climate in a Transitional Climatic Zone in Northwest China

80%

Zhang L. , Jiang Y. , Zhao S. , Zhang W.

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tom Vol. 66, nr 2

114--125

EN

Study of the radial growth response to climate factors at different tree ages is essential for predicting forest dynamics and formulating correct management policies. In this study, we analysed the growth responsiveness of Picea crassifolia to climate conditions, and evaluated its relationship to tree age at the individual tree scale, in the transitional zone between regions affected by the East Asian monsoon and winds blowing from the west (westerlies) in the Qilian Mountains. On three study sites, 150 cores were taken from 75 trees. Pearson correlation coefficients were calculated between the standardized tree-ring series of each core (and chronology) and climatic factors which were utilized to research the climate-growth relationships. Quadratic polynomial fitting was used to test the relationships between tree age, chronological parameters, and the radial growth response to climate. Radial growth was positively influenced by total precipitation for the previous July-September and the current May-July. Additionally, radial growth was negatively correlated with the total monthly precipitation for the current September, and the mean monthly temperature for the previous July. Trees younger than 80 years old showed a stronger response to accumulative precipitation in the previous July-September, those older than 160 years old showed a stronger response to precipitation at the end of current growing season, while those of 140-160 years old showed a weaker response to precipitation in the current May-July.

7

Spatial spillover effects of environmental regulations on China’s haze pollution based on static and dynamic spatial Panel data models

71%

Liu X. , Li L. , Ge J. , Tang D. , Zhao S.

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nr 4

EN

Rapid industrialization and urbanization have presented a dilemma to traditional environmental policies, and severe haze pollution has attracted particular attention in China. This paper employed the exploratory spatial data analysis technique to analyze global and local spatial auto-correlation of environmental regulations (ERS) and haze pollution. Static and dynamic spatial panel data models were further established to investigate the influence of ERS and its spatial spillover effect on haze pollution across 31 provinces of China in 2005-2015. Results showed that significant spatial autocorrelation existed for both ERS and haze pollution in China, forming different aggregation regions in terms of geographical distribution. There was strong evidence for the “inverted-U”-shaped EKC relationship between ERS and haze pollution regardless of whether it was the static or dynamic spatial econometric model. In addition, haze pollution was not only affected by economic growth, population size, and urbanization, but also by the haze pollution in the previous period. Conclusions and control strategies that would be of great significance for implementing effective management measures were synoptically discussed.

8

The implementation of the Balanced Critical Factor Index methodology in the strategy redevelopment process

71%

Rymaszewska A. , Koskinen J. , Takala J. , Zhao S. , Chen Y.

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2013

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tom Vol. 4, No. 1

50-56

EN

Strategic planning and development is a critical yet often overlooked issue in company's operations. The planning of development as well as addressing the distribution of available resources should be done systematically rather than instinctively however, many companies still do not have any reliable method that would facilitate the decision making processes at their disposal. This article aims at presenting the innovative analytical method- Balanced Critical Factor Index (BCFI) for addressing the need for change in company's operational strategy according to changes in available technology and knowledge. By examining a wide array of indexes, the presented method is expected to suggest the directions of development. The presented method also addresses the challenges of the complex process of decision-making. Moreover, the empirical evidence gathered in the studied case company serves as a source of important feedback regarding the further improvement of the BCFI method.

9

Removal efficiency and the mineralization mechanism during enhanced bioventing remediation of oil-contaminated soils

61%

Jia J. , Zhao S. , Hu L. , Wang Y. , Yao L. , Liu Y. , Yuan Z.

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2016

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tom 25

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nr 5

EN

The environmental challenge of crude oil-contaminated soil is difficult to address due to its complicated components and the mechanism of material transformation. In order to study the bioremediation of soil contaminated by crude oil, we designed five simulation test systems: a sterilization system, an oxygenated and water-controlled system, a nitrogen (N)/phosphorus (P) adjusted system, a broth-added system, and a double-broth-added system. The results show that the highest removal of crude oil from soil was increased to 34.23% by regulating the micro-ecological environment after 91 days in a simulation system. Regulating N and P can effectively strengthen the mineralization action of microorganisms on crude oil. Biodegradation had the most effect on the removal of oil, accounting for more than 58% of the total removal. Moreover, mineralization was dominant in biodegradation. Degradation of crude oil components was alkanes-based, accounting for 50 to 80% of total oil removal. By regulating moisture, temperature, oxygen content, N/P levels, and enrichment broth, the half-life of crude oil in a simulation system can be shortened to 182 days.

10

Different responses of the radial growth of conifer species to increasing temperature along altitude gradient: Pinus tabulaeformis in the Helan Mountains (Northwestern China)

61%

Zhang L. , Jiang Y. , Zhao S. , Dong M. , Chen H. Y. H. , Kang X.

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nr 4

EN

Linking the response of tree growth to global warming is a key to fully appreciating the impact of climate change on forests. To examine the impacts of temperature and precipitation on tree growth, we studied the radial growth of Pinus tabulaeformis along an altitude gradient from 2032 m a.s.l. to 2361 m a.s.l. on the Helan Mountains, which is almost the northwestern limit of P. tabulaeformis distribution in China. The results showed that, radial growth of P. tabulaeformis decreased significantly (P <0.05) at the low altitude (2032 m a.s.l.) and remained almost steady at the middle and high altitude (2200 m a.s.l. and 2361 m a.s.l.) during the past decades, which was attributed to different climate-radial growth relationships at different altitudes. Total precipitation from the previous July to the current June was an important and effective climatic factor for radial growth at all altitudes. Radial growth was negatively correlated with the mean temperature of the current March at the low altitude and was positively and negatively correlated with the mean temperature of the previous October and the current July at the high altitude, respectively. Increasing temperature of the March under the context of global warming was the main reason for growth reduction at the low altitude. Radial growth at the middle and high altitudes didn't suffer from global warming. It was inferred that conifers at low altitudes of the species' dry distribution limit were more vulnerable to global warming. To cope with possible intensified drought in the growing season and growth reduction in the future, thinning and afforestation should be carried out in the forests, especially at low altitudes.

11

Different Responses of the Radial Growth of Conifer Species to Increasing Temperature along Altitude Gradient : Pinus tabulaeformis in the Helan Mountains (Northwestern China)

61%

Zhang L. , Jiang Y. , Zhao S. , Dong M. , Chen H. Y. H. , Kang X.

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tom Vol. 64, nr 4

509--525

EN

Linking the response of tree growth to global warming is a key to fully appreciating the impact of climate change on forests. To examine the impacts of temperature and precipitation on tree growth, we studied the radial growth of Pinus tabulaeformis along an altitude gradient from 2032 m a.s.l. to 2361 m a.s.l. on the Helan Mountains, which is almost the northwestern limit of P. tabulaeformis distribution in China. The results showed that, radial growth of P. tabulaeformis decreased significantly (P <0.05) at the low altitude (2032 m a.s.l.) and remained almost steady at the middle and high altitude (2200 m a.s.l. and 2361 m a.s.l.) during the past decades, which was attributed to different climate-radial growth relationships at different altitudes. Total precipitation from the previous July to the current June was an important and effective climatic factor for radial growth at all altitudes. Radial growth was negatively correlated with the mean temperature of the current March at the low altitude and was positively and negatively correlated with the mean temperature of the previous October and the current July at the high altitude, respectively. Increasing temperature of the March under the context of global warming was the main reason for growth reduction at the low altitude. Radial growth at the middle and high altitudes didn't suffer from global warming. It was inferred that conifers at low altitudes of the species' dry distribution limit were more vulnerable to global warming. To cope with possible intensified drought in the growing season and growth reduction in the future, thinning and afforestation should be carried out in the forests, especially at low altitudes.

12

Low-temperature pyrolysis of oily sludge : roles of Fe/Al-pillared bentonites

61%

Jia H. , Zhao S. , Zhou X. , Qu C. , Fan D. , Wang C.

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2017

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tom Vol. 43, no. 3

82--90

EN

Pyrolysis is potentially an effective treatment of oily sludge for oil recovery, and the addition of a catalyst is expected to affect its pyrolysis behavior. In the present study, Fe/Al-pillared bentonite with various Fe/Al ratios as pyrolysis catalyst is prepared and characterized by XRD, N2 adsorption, and NH3-TPD. The integration of Al and Fe in the bentonite interlayers to form pillared clay is evidenced by increase in the basal spacing. As a result, a critical ratio of Fe/Al exists in the Fe/Al-pillared bentonite catalytic pyrolysis for oil recovery from the sludge. The oil yield increases with respect to increase in Fe/Al ratio of catalysts, then decreases with further increasing of Fe/Al ratio. The optimum oil yield using 2.0 wt% of Fe/Al 0.5-pillared bentonite as catalyst attains to 52.46% compared to 29.23% without catalyst addition in the present study. In addition, the addition of Fe/Al-pillared bentonite catalyst also improves the quality of pyrolysis-produced oil and promotes the formation of CH4. Fe/Al-pillared bentonite provides acid center in the inner surface, which is beneficial to the cracking reaction of oil molecules in pyrolysis process. The present work implies that Fe/Al-pillared bentonite as addictive holds great potential in industrial pyrolysis of oily sludge.

13

Study on power efficiency of vortex beam propagation through an optical system with phase optimization

51%

Wu H. , Sheng S. , Huang Z. , Wang H. , Zhao S. , Xu X. , Sun Z. , Xiao R.

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tom Vol. 42, nr 3

597-611

EN

Beam blocked and truncated by the receiver causes serious power losses in beam uplink propagation in a relay mirror system. We propose a method to improve power efficiency of beam uplink propagation in the relay mirror system by using vortex source and phase optimization. A typical model of beam uplink propagation in the relay mirror system is established. With this model, the principle of the method is theoretically analyzed, and power efficiencies of beam uplink propagation under different conditions are calculated. The calculation results show that power efficiency of beam uplink propagation can be improved from 86.44% to 97.86% by using vortex source and phase optimization. A reduced-scale experiment of beam uplink propagation in the relay mirror system under the "closed-loop" mode is performed, and the experimental results show that power efficiency can be improved from 71.89% to 91.59% by using the vortex source and phase optimization.

14

Environmental toxicity analysis and reduction of ceramsite synthesis from industrial coal gasification coarse cinder waste

51%

Jia J. , Hu L. , Zheng J. , Zhai Y. , Yao P. , Zhao S. , Shi S. , Zhai X. , Zhang D.

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nr 1

EN

Coal gasification coarse cinder (CGCC) is the main waste in the coal gasification industry, containing low calorific value but high heavy metal residuals. To achieve environmental toxicity stabilization and waste recycling, we developed a manufacturing method of multiple-functional ceramsite from CGCC by pelletizing and sintering. By altering key parameters during the manufacturing process (including CGCC content, sintering temperature, and time), the physical properties and leaching toxicity of ceramsite were evaluated. Sintering temperature was identified with a significantly positive relationship with ceramsite’s compressive strength, whereas CGCC content was negatively correlated with water adsorption. The highest compressive strength (24.00 MPa) and relatively lower water absorption (21.36%) was achieved at 50% CGCC content and 1,150ºC sintering for 30 min. The toxicity tests showed acceptable leaching heavy metals with minimal environmental impact. Considering the energy conservation and the maximal recycling of CGCC, optimal ceramsite manufacturing is suggested as 50% CGCC content and 1,150ºC/10 min sintering temperature/time. Our results indicated that multiple-functional ceramsite manufacturing is a low-cost and environmentally friendly approach for CGCC recycling.

15

Isolation of biosynthesis related transcripts of 2,3,5,4'-tetrahydroxy stilbene-2-O-beta-D-glucoside from Fallopia multiflora by suppression subtractive hybridization

51%

Zhao W. , Sheng S. , Liu Z. , Lu D. , Zhu K. , Li X. , Zhao S. , Yao Y.

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nr 2

EN

2,3,5,4'-tetrahydroxy stilbene-2-O-ß-D-glucoside (THSG) exerts multiple pharmacodynamic actions, found in Fallopia multiflora, but the biosynthesis pathway of THSG is still unclear. To clear this ambiguity, we constructed suppression subtractive hybridization (SSH) libraries to screen the genes involved in THSG biosynthesis from two F. multiflora varieties, which vary significantly in THSG content. Twelve non-redundant differentially expressed sequence tags were obtained and the full lengths of 4 unreported fragments were amplified by rapid amplification of cDNA ends. We totally got 7 fulllength transcripts, and all of them were aligned to the transcriptome and digital gene expression tag profiling database of four F. multiflora tissues (root, stem and leaf from Deqing F. multiflora and another root from Chongqing F. multiflora; data unpublished) using local BLAST. The results showed that there was a significant, organ specific difference in the expression of fragments and full-length sequences. All the sequences were annotated by aligning to nucleotide and protein databases. Kyoto Encyclopedia of Genes and Genomes pathway analysis indicated that THSG biosynthesis was correlated with multiple life activities.

16

Reactive oxygen species mediated placental oxidative stress, mitochondrial content, and cell cycle progression through mitogen-activated protein kinases in intrauterine growth restricted pigs

51%

Luo Z. , Luo W. , Li S. , Zhao S. , Sho T. , Xu X. , Zhang J. , Xu W. , Xu J.

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nr 4

17

Photosynthetic characterization of Jerusalem artichoke during leaf expansion

51%

Yan K. , Chen P. , Shao H. , Zhao S. , Zhang L. , Zhang L. , Xu G. , Sun J.

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2012

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tom 34

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nr 1

EN

Gas exchange, chlorophyll a fluorescence and modulated 820 nm reflection were investigated to explore the development of photosynthesis in Jerusalem artichoke (Helianthus tuberosus L.) leaves from initiation to full expansion. During leaf expansion, photosynthetic rate (Pn) increased and reached the maximal level when leaves were fully expanded. The same change pattern was also found in the stomatal conductance and chlorophyll content. Lower Pn could not be ascribed to the higher stomatal resistance in developing leaves, as intercellular CO₂ concentration was not significantly lower in these leaves. Lower Pn partly resulted from the lower actual photochemical efficiency of PSII in developing leaves, as more excited energy was dissipated through non-photochemical quenching. The development of primary photochemical reaction and electron transport in the donor side of PSII was completed in the initiating leaves. However, the development of electron transport in the acceptor side of PSII was not accomplished until leaves were fully expanded, indicated by the change in probability that an electron moves further than primary quinone (ψo). PSI activity changed in parallel with ψo suggesting that PSI cooperated well with PSII during leaf expansion. It should be stressed that the development of carbon fixation process was later than primary photochemical reaction but earlier than photosynthetic electron transport during leaf expansion. The later development of photosynthetic electron transport may reduce the production of reactive oxygen species from Mehler reaction, particularly under low carbon fixation.

18

Concentrations of heavy metals in six municipal sludges from Guangzhou and their potential ecological risk assessment for agricultural land use

51%

Liu J. , Zhou Z. , Sun S. , Ning X. , Zhao S. , Xie W. , Wang Y. , Zheng L. , Huang R. , Li B.

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nr 1

EN

Six kinds of municipal sludge samples were collected from wastewater treatment plants (WWTPs) from Guangzhou in southern China. Total concentration of Cu, Pb, Zn, Cr, Ni, Cd, and Mn in the sludge was determined, and used obtained values to appraise the degree of agricultural land pollution on the base of four pollution indixes. Results showed that the concentrations of the heavy metals Cu (4.567 mg/kg), Mn (1.844 mg/kg), Ni (148 mg/kg), Cr (121 mg/kg), and Cd (5.99 mg/kg) in S1 sludge were higher than that of the other sludges. In six sludge samples the concentrations of Mn, Zn, and Cu were highest, followed by Ni, Pb, and Cr. Cd had the lowest concentration. All were higher than those recorded in the background data for crop soils. With the exception of Cu and Cd from site S1, and Ni from sites S1, S2, and S5, all other metal concentrations conformed to permissible levels prescribed by the national application standard of acid soil in China (GB18918-2002). The geoaccumulation index (Igeo) assessment results indicate that there are serious risks in agricultural utilization for the existing Cu and Zn in these six kinds of sludges, especially the Igeo, which was 6.53 for Cu, 3.21 for Mn, 2.78 for Cd in the S1 sludge. The results of RI showed that sludge had high potential ecological risks, especially caused by Cd, which should give rise to widespread concerns. The potential ecological risk index (RI) of heavy metals in six sludge samples was ranked in the order of S1>S2>S4>S3>S5>S6.

19

Influence of space charged particles on satellite optical communication system

51%

Hou R. , Zhao S. , Xu J. , Wu J. , Li Y. , Zhan S. , Shi L. , Fang S.

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2009

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tom Vol. 39, nr 2

251-265

EN

Although research of satellite optical communication system has been carried out for many years, there is scarce literature to comprehensively analyze the influence of space environment on satellite optical communication system. Different kinds of particles and fields exist in the space environment, including high energy charged particles, solar radiation, plasma environment, space fragment, etc. The Influence of space charged particles on satellite optical communication system was investigated in detail, which mainly related to single event upset (SEU), total dose effect and plasma environment. For SEU analysis the relation between single proton upset rate and satellite orbit was analyzed in detail. The reliability index of equipment based on SEU was proposed, the numerical calculation results have proved that the SEU effect was relatively less and corresponded to higher reliability of SRAM/MOS equipment under lower orbit altitude and inclination. For plasma environment analysis there is no obvious influence of plasma on laser signal transmission. But charging and discharging processes on satellite surface would lead to the malfunction of satellite communication system. The influence of charged particles and its related plasma on satellite optical communication system was investigated, which would be helpful for the design and the improvement of performance of satellite optical communication system.

20

Decreased expression of the human carbonyl reductase 2 gene HCR2 in hepatocellular carcinoma

51%

Liu S. , Ma L. , Huang W. , Shai Y. , Ji X. , Ding L. , Liu Y. , Yu L. , Zhao S.

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nr 2

EN

Altered gene expression was associated with the induction and maintenance of hepatocellular carcinoma (HCC). To determine the significance of HCR2 in HCC, here we compare the expression levels of HCR2 in carcinoma and in paired non-carcinoma tissues using semiquantitative reverse-transcription polymerase chain reaction (RT-PCR), Western blot analysis, and immunohistochemical staining. The expression ratio (ER) of HCR2 between the tumor and paired tumor-free tissues was calculated for each case and the data was clinicopathologically analyzed. The expression of HCR2 mRNA was found to be significantly decreased in HCC tissues compared with paired normal tissues (P < 0.001). HCR2 was downregulated in 58% (n = 22) of 38 HCC patients. The ER of HCR2 was higher in Edmondson’s grade I/II carcinomas than that in Edmondson’s grade III/IV carcinomas (P < 0.05). Western blot analysis showed HCR2 to be notably depressed in carcinoma tissues in 3 out of 4 HCC patients. Immunohistochemical staining indicated most HCR2 protein accumulated in non-carcinoma cells. These results suggested that altered HCR2 expression might play roles in the carcinogenesis and progression of HCC, and it could be a clinical marker for prognosis, and a molecular target for screening potential anti-HCC drugs.