Guangdong Province Science and Technology Library

This review summarizes recent advances in blue OLEDs based on fluorescence emitters, especially focusing on the different mechanisms involving the emitters and devices.

Abstract. The North China Plain (NCP) has a serious shortage of freshwater resources, and crop production consumes approximately 75 % of the region's water. To estimate water consumption of different crops and crop structures in the NCP, the Hebei southern plain (HSP) was selected as a study area, as it is a typical region of groundwater overdraft in the NCP. In this study, the water footprint (WF) of crop production, comprised of green, blue and grey water footprints, and its annual variation were analyzed. The results demonstrated the following: (1) the WF from the production of main crops was 41.8 km3 in 2012. Winter wheat, summer maize and vegetables were the top water-consuming crops in the HSP. The water footprint intensity (WFI) of cotton was the largest, and for vegetables, it was the smallest; (2) the total WF, WFblue, WFgreen and WFgrey for 13 years (2000–2012) of crop production were 604.8, 288.5, 141.3 and 175.0 km3, respectively, with an annual downtrend from 2000 to 2012; (3) winter wheat, summer maize and vegetables consumed the most groundwater, and their blue water footprint (WFblue) accounted for 74.2 % of the total WFblue in the HSP; (4) the crop structure scenarios analysis indicated that, with approximately 20 % of arable land cultivated with winter wheat–summer maize in rotation, 38.99 % spring maize, 10 % vegetables and 10 % fruiters, a sustainable utilization of groundwater resources can be promoted, and a sufficient supply of food, including vegetables and fruits, can be ensured in the HSP.

Electron acceptor redox potential (EARP) was presumed to be a determining factor for microbial metabolism in many natural and engineered processes. However, little is known about the potentially global effects of EARP on bacteria. In this study, we compared the physiological and transcriptomic properties of Shewanella decolorationis S12 respiring with different EARPs in microbial electrochemical systems to avoid the effects caused by the other physicochemical properties of real electron acceptor. Results showed that the metabolic activities of strain S12 were nonlinear responses to EARP. The tricarboxylic acid cycle for central carbon metabolism was down-regulated while glyoxylate shunt was up-regulated at 0.8 V compared to 0.2 and -0.2 V, which suggested that EARP is an important but not the only determinant for metabolic pathways of strain S12. Moreover, few cytochrome c genes were differentially expressed at different EARPs. The energy intensive flagella assembly and assimilatory sulfur metabolism pathways were significantly enriched at 0.8 V, which suggested strain S12 had stronger electrokinesis behavior and oxidative stress-response at high EARP. This study provides the first global information of EARP regulations on microbial metabolism, which will be helpful for understanding microorganism respiration.

Edited version of a paper presented at the World Library and Information Congress, 69th IFLA General Conference, Berlin, Germany, 1-8 August 2003. There are already more than 20.83 million host computers and 59.10 million Internet users in China. Most of them get access to the Internet at home, office or school, and a few at the library. Their needs for e-books or science and education are among what they mostly searched for through the Internet. It has been predicated that a lot of reading is done outside the library. How has the Internet been used to encourage reading in China? This paper looks at three noticeable ways starting from news online, digital journals and e-books, the printed editions of which are the main categories of traditional publications. It is also pointed out what would improve reading further, and how traditional publishing and libraries have been affected.

Bacteria promoters along with operators are crucial elements in the control of gene expression in microbes in response to environmental stress changes. A genome-wide promoter DNA regulatory library is in demand to be developed for a microbe reporter method to monitor the existence of any given environmental stress substance. In this study, we utilized Escherichia coli (E. coli) as a model system for the preparation of both cell lysates and genomic DNA fragments. Through enriching protein-bound DNA fragments to construct luciferase reporter libraries, we found that, of 280 clones collected and sequenced, 131 clones contained either the promoter-35 and -10 conservative sequences and/or an operator transcription factor binding sites (TFBS) region. To demonstrate the functionality of the identified clones, five of 131 clones containing LexA binding sequence have been demonstrated to be induced in response to mitomycin C treatment. To evaluate our libraries as a functional screening library, 80 randomly picked up clones were cultured and treated with and without MMC, where two clones were shown to have greater than twofold induction. In addition, two arsenite-responsive clones were identified from 90 clones, one having the well-known ArsR and another having the osmotically inducible lipoprotein (OsmE1). The newly discovered osmE1 has been quantitatively validated to be induced by arsenite treatment with real-time PCR in a dose response and time course manner. This enriching protein-bound DNA luciferase reporter libraries and functional screening facilitate the identification of stress-responsive transcriptional factors in microbes. We developed functional libraries containing E. coli genomic-wide protein-bound DNA as enhancers/operators to regulate downstream luciferase in response to stress.

With sod culture in orchards as background and the native arbuscular mycorrhizal(AM) fungi in orchard soil as target,the influences of Stylosanthes gracilis,Ageratum conyzoides and Paspalum notatum on the growth and community structure of AM fungi were investigated.Results showed that the root colonization rate of S.gracilis(62.2%) was higher than that of A.conyzoides(36.5%) and P.notatum(37.3%).The arbuscule percentage showed a similar pattern.Although the biomass and P content in the shoots of the three grass species were comparable,P content in S.gracilis roots was higher than that in A.conyzoides and P.notatum roots.The species richness and hyphal density in the rhizosphere soil of S.gracilis plants were less than those of A.conyzoides and P.notatum plants,while the spore density was highest for A.conyzoides and lowest for P.notatum.Diversity index of the native AM fungi in the rhizosphere soil of P.notatum plants was slightly higher than those of S.gracilis and A.conyzoides plants.PCR-DGGE analysis was consistent with the morphological results.Our results indicate that the community structure of native AM fungi in orchard soil differed from each other when colonized with different grass species,which should be taken into account when selecting appropriate grass species for sod culture.

Arbuscular mycorrhizal(AM) fungi can help plant to remedy the heavy metal-contaminated soil.In the present study,30 soil samples and the corresponding plant root samples were collected from Dabao Mountains,North Guangdong.The results revealed that the contents of Cu,Zn,Pb and Cd in 27 soil samples from contaminated areas exceeded the national standard at different levels.Following the staining of root samples and the observation for AM fungi colonization,81.5% of root samples from contaminated areas were found to be colonized by AM fungi.A certain amount of AM fungi spores and hyphae were also present in the corresponding soils.The diverse AM fungi existed in the contaminated soils at Dabao Mountains.

Based on the effectiveness and problems of specialized town urbanization construction in Guangdong in the past, this paper analyzes the top-level design perspective and the implementation of specialized towns’ new-style urbanization. The inclusions show that good relationship between the government and the market, excellent combination between local urbanization and remote urbanization can effectively promote the specialized towns’ new-style urbanization. At the same time, this paper also resolves some cognitive misunderstandings, such as the “urban-rural integration”, “equalization of urban and rural public services”.

The paper discusses the deficiency of theory research on reading,reading habit and so on at first.Then,based on the reason why the present reading rate in the society declines,it probes into the topic of how to create a readingoriented society by actual steps from ten aspects,such as reading research should concern actual situation,the state should take reading as a basic guideline of the development of culture and education,readers service in library should be strengthened,reading environment should be improved,reading activities should be launched in the society so as to form peoples reading habits and their reading orientation from their childhood.

Based on an econometric validation analysis of "fuzzy set" panel data, this paper verifies the effectiveness of the "Four-step Progressive" teaching method in teaching entrepreneurship courses for students at polytechnic colleges. It is basically concluded that the method is significantly related to the employment and entrepreneurship of college students, and can provide some reference for the teaching reform of vocational education.

Trivalent europium ion (Eu 3+ )-based phosphors have emerged as promising candidates for advancing the performance of white light-emitting-diodes (WLEDs) due to their characteristic narrow-band red emission from 5 D 0 → 7 F 1,2 transitions. High Eu 3+ concentration could optimize absorption efficiency but also trigger emission attenuation owing to the concentration quenching effect. Herein, we develop a unique class of efficient red-emitting phosphors without occurring concentration quenching, K 7 SrLu 2(1- x ) B 15 O 30 : x Eu 3+ (0≤x ≤ 1), exhibiting sharp red emission peaking at 619 nm upon excitation with a 393 nm. The increasing proportion of Eu 3+ in the K 7 SrLu 2 B 15 O 30 host can raise the emission intensity monotonously until the Eu 3+ concentration comes to 100%, while no distortion has been observed in the nature of the crystal structure. The concentration anti-quenching effect can be ascribed to the limitation of energy transfer due to the effective separation of neighboring [LuO 6 ] octahedral in crystal lattice. Consequently, the optimal K 7 SrEu 2 B 15 O 30 (KSEBO) phosphor achieves a high internal quantum efficiency (IQE) of 80.62%, excellent color purity of 92.69%, and retains 74% of the initial intensity at 423 K. The WLEDs device fabricated with the K 7 SrEu 2 B 15 O 30 phosphor presents a high general color rendering index (CRI) of 85.2 and low correlated color temperature (CCT) of 4409 K, demonstrating the developed phosphor applicable as a red component in warm WLEDs. • A novel K 7 SrLu 2 B 15 O 30 :Eu 3+ borate red-emitting phosphors is firstly designed and synthesized. • The red phosphor shows unique luminescence properties without concentration quenching and high 80.62% quantum yield. • The assembled LED device realizes excellent warm white light with promising application prospects.

The public-private partnership (PPP) model meets the public's demand for infrastructure while easing the government's financial burden. To ensure the standardisation and orderly development of PPP projects, a comprehensive audit of all economic activities throughout the project life cycle is necessary, from initiation to handover. However, challenges inherent in PPP auditing, such as lengthy audit cycles, the involvement of multiple entities, and complex audit requirements, increasingly conflict with traditional auditing methods. Blockchain technology, with its unique features including tamper-proof timestamps and smart contracts, provides an effective solution to these challenges. This study analyses the necessity and feasibility of integrating blockchain technology into the full lifecycle auditing of PPP projects. Additionally, it proposes a practical integration framework to facilitate the application of blockchain in PPP auditing, aiming to improve audit efficiency and reliability.

The article talks about how library shall be located,and probes into the development strategy for library of science and technology in new environment.

Along with the development of modern society and information age,the course of lectures gradually becomes one of the important service methods in library.It has many positive effects,such as broadening the realm of service,intensifying functions of social education,and upgrading library brand image,etc.

The paper analyzes the problems existing in the development of electronic periodical and in the service, and probes into the establishment of the integrated system of electronic periodical, making full use of free electronic resources, etc.

This paper discusses the problems in the law schedule in Chinese Library Classification(Forth Editon).These include how to coordinate between the first law schedule and the second law schedule,how to standardize the annotation of the classification,how to standardize the name of the classification etc..

This paper draws the knowledge graphs of competitive intelligence with the Citespace software based on the CSSCI database.The paper reveals status of the area objectively through the visual analysis of the main research institutions and representatives,knowledge base and important nodes,research front as well as the research hotspots.

After analyzing the meaning of the responsibility in a book with more responsible persons, this paper puts forward that we must recognize the principal responsibility and the secondary responsibility so as to describe the responsibility area correctly.

In this paper, the significance and feasibility of constructing the Environmental Science Document Open Platform of South China (ESDOP) are analyzed. Some ideas of working on the ESDOP are given, particularly on the framework of data platform, contents of document database, and technical diagram, etc.. Finally, some expected functions of ESDOP are discussed.

The article brings up an assumption on the knowledge network construction of the current library according to the knowledge management issues during the process of the transition of library to the research library,and discusses the issues of the knowledge network system construction of the current library based on its analysis of goals and needs,ability and the constituent elements.