1,721,777 research outputs found
Case study on dairy value chain in China
No full textPresented by Hongmin Dong and Sha Wei, Chinese Academy of Agricultural Sciences (CAAS), on 28 June 2021 at the Asian Development Bank (ADB) Webinar on Sustainable Protein Case Study: Outputs and Synthesis of Results
In-orbit performance of the laser interferometer of Taiji-1 experimental satellite
No full textTaiji-1, which is the first experimental satellite for space gravitational wave detection in China, relies on key technologies which include the laser interferometer, the gravitational reference sensor (GRS), the micro-thruster and the satellite platform. Similarly to the Laser Interferometer Space Antenna (LISA) pathfinder, except for the science interferometer, the optical bench (OB) of Taiji-1 contains reference and test mass (TM) interferometers. Limited by the lower mechanical strength of the carrier rocket and by the orbit environment, the OB of Taiji-1 is made of invar steel and fused silica, and it is aimed to achieve a sensitivity of the order of 100 pm/root Hz. The experimental results from in-orbit tests of Taiji-1 demonstrate that the interferometer can reach a sensitivity of 30 pm/root Hz in the frequency range of 0.01-10 Hz, which satisfies the requirements of Taiji-1 mission
Multi-parameter optimisation of optical bonding for the ultra-stable optical measurement bench in space-based platform
No full textTo enhance the measurement accuracy of space-based platforms, the construction of optical platforms imposes higher performance demands on optical bonding technology. Hydroxide Catalysis Bonding (HCB) technology, with its advantages of low stress and high precision, has emerged as a critical technique for achieving this objective. However, the performance optimisation and application of HCB under multi-parameter influences still require further systematic investigation. This study, using the developed mathematical model and experimental validation, systematically examines the effects of solution concentration, solution volume, curing temperature, and surface shape error on bonding time, strength, and stability. The experiments identified the optimal process parameters: 1:300 Molar ratio, 0.8 mu L solution volume, 0.1 lambda surface shape error, and a bonding area of 2 cm2, while confirming the pronounced impact of high-temperature curing in accelerating bonding time and enhancing bonding strength. The research reveals that a plane-convex combination exhibits superior strength performance under low RMS error (<= 0.6 lambda), while spot displacement tests indicate that the deflection angle of the bonding structure during curing can be maintained stably within 10 arcsec. Based on the optimised parameters and conclusions, the Chinese "Taiji" ultra-stable optical measurement bench (USOMB) achieved optical bonding, and passed noise stability measurement. The results demonstrate that the platform achieves noise levels below 10 pm/ / in the 0.1 Hz to 1 Hz range, reaching pm/ Hz /Hzat 1 Hz, a reduction of approximately two orders of magnitude compared to "Taiji-1". These findings provide technical support for the construction of the USOMB in the "Taiji Program"
Radiological characterisation of alkali-activated construction materials containing red mud, fly ash and ground granulated blast-furnace slag
No full textPoor storage of industrial wastes has been a cause of land contamination issues. These wastes or by-products have the potential to be used as secondary raw materials in construction, promoting the concept of a circular economy that will avoid land contamination. Here we evaluate radiological environmental impacts when wastes that contain elevated levels of naturally occurring radionuclides (NORs) such as red mud, fly ash and ground granulated blast furnace slag are made into ‘green cements’ such as geopolymers or alkali-activated materials (AAMs). During the study, three AAM concrete and mortar series with various mixing ratios were prepared and investigated. The NOR content, I-Index, radon emanation and exhalation of the precursor waste materials and their cement products were measured and calculated and the strength of the cement products was compared. The emanation and the exhalation properties were calculated for the final products, weighing the data of the components as a function of their mixing ratio. The I-index alone suggested that the AAMs would be suitable products. AAMs containing ground granulated blast furnace slag exhibited the lowest radon exhalation and higher compressive strength, while the fly ash and red mud AAMs had increased final radon exhalation. In the case of fly ash, alkaline activation of fly ash dramatically increased the radon exhalation; the highest measured fly ash exhalation was 1.49 times of the theoretically calculated exhalation value. This highlights the increased risk of using fly ash as a component in AAMs and the need to carry out testing on the final products as well as individual secondary raw materials.</p
Design and Construction of the Optical Bench Interferometer for the Taiji Program
No full textA kind of full-function two-sided optical bench interferometer (OBI) is designed to meet the practical requirements of the Taiji Program for space gravitational wave detection. The main optical paths are arranged on the A-side for transmission and interference, and other optical paths and electronic devices are placed on the B-side. According to the design scheme, we successfully constructed two OBIs by using hydrogen-oxygen catalytic stress-free bonding technology. When the OBI is installed and adjusted, the position and Angle error of the interference beam are controlled within 30 mu m and 50 mu rad through the self-designed precision mechanical clamping mechanism and beam position measuring device. The built OBI was placed on the vibration isolation platform in the vacuum tank for the stability test. The test results show that the noise of the OBI is less than 10 pm/root Hz in the frequency band of 0.1 Hz to 1 Hz, which meets the noise budget requirements of the Taiji Pathfinder in the middle- and high-frequency band
Going Beyond Counting First Authors in Author Co-citation Analysis
Full text linkThe present study examines one of the fundamental aspects of author co-citation analysis (ACA) - the way co-citation
counts are defined. Co-citation counting provides the data on which all subsequent statistical analyses and mappings
are based, and we compare ACA results based on two different types of co-citation counting - the traditional type that
only counts the first one among a cited work's authors on the one hand and a non-traditional type that takes into
account the first 5 authors of a cited work on the other hand. Results indicate that the picture produced through this non-traditional author co-citation counting contains more coherent author groups and is therefore considerably clearer. However, this picture represents fewer specialties in the research field being studied than that produced through the traditional first-author co-citation counting when the same number of top-ranked authors is selected and analyzed. Reasons for these effects are discussed
Variations on the Author
Full text link“Variations on the Author” discusses two of Eduardo Coutinho’s recent films (Um Dia na Vida, from 2010, and Últimas Conversas, posthumously released in 2015) and their contribution to the general question of documentary authorship. The director’s filmography is characterized by a consistent yet self-effacing form of authorial self-inscription: Coutinho often features as an interviewer that rather than express opinions propels discourses; an interviewer that is good at listening. This mode of self-inscription characterizes him as an author who is not expressive but who is nonetheless markedly present on the screen. In Um Dia na Vida, however, Coutinho is completely absent form the image, while Últimas Conversas, on the contrary, includes a confessional prologue that moves the director from the margins to the center of his films. This article examines the ways in which these works stand out in the filmography of a director who offers new insights into the notion of cinematic authorship
Appropriate Similarity Measures for Author Cocitation Analysis
Full text linkWe provide a number of new insights into the methodological discussion about author cocitation analysis. We first argue that the use of the Pearson correlation for measuring the similarity between authors’ cocitation profiles is not very satisfactory. We then discuss what kind of similarity measures may be used as an alternative to the Pearson correlation. We consider three similarity measures in particular. One is the well-known cosine. The other two similarity measures have not been used before in the bibliometric literature. Finally, we show by means of an example that our findings have a high practical relevance.information science;Pearson correlation;cosine;similarity measure;author cocitation analysis
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