Informacja

Drogi użytkowniku, aplikacja do prawidłowego działania wymaga obsługi JavaScript. Proszę włącz obsługę JavaScript w Twojej przeglądarce.

Wyszukujesz frazę "Yan, Li" wg kryterium: Autor


Tytuł:
The history of arsenical pesticides and health risks related to the use of Agent Blue
Autorzy:
Bencko, Vladimir
Yan Li Foong, Florence
Tematy:
arsenicals in agriculture
organic arsenicals use
farmers’ health
arsenical pesticides
carcinogenicity
agent blue toxicity
Pokaż więcej
Wydawca:
Instytut Medycyny Wsi
Powiązania:
https://bibliotekanauki.pl/articles/989807.pdf  Link otwiera się w nowym oknie
Opis:
Arsenicals in agriculture. Beginning in the 1970s, the use of arsenic compounds for such purposes as wood preservatives, began to grow. By 1980, in the USA, 70% of arsenic had been consumed for the production of wood preservatives. This practice was later stopped, due to the US Environmental Protection Agency (EPA) ban of the arsenic-and chromium-based wood preservative chromated copper arsenate. In the past, arsenical herbicides containing cacodylic acid as an active ingredient have been used extensively in the USA, from golf courses to cotton fields, and drying-out the plants before harvesting. The original commercial form of Agent Blue was among 10 toxic insecticides, fungicides and herbicides partially deregulated by the US EPA in February 2004, and specific limits on toxic residues in meat, milk, poultry and eggs, were removed. Today, however, they are no longer used as weed-killers, with one exception – monosodium methanearsonate (MSMA), a broadleaf weed herbicide for use on cotton. Severe poisonings from cacodylic acid caused headache, dizziness, vomiting, profuse and watery diarrhea, followed by dehydration, gradual fall in blood pressure, stupor, convulsions, general paralysis and possible risk of death within 3–14 days. The relatively frequent use of arsenic and its compounds in both industry and agriculture points to a wide spectrum of opportunities for human exposure. This exposure can be via inhalation of airborne arsenic, contaminated drinking water, beverages, or from food and drugs. Today, acute organic arsenical poisonings are mostly accidental. Considerable concern has developed surrounding its delayed effects, for its genotoxic and carcinogenic potential, which has been demonstrated in epidemiological studies and subsequent animal experiments. Conclusions. There is substantial epidemiological evidence for an excessive risk, mostly for skin and lung cancer, among humans exposed to organic arsenicals in occupational and environmental settings. Furthermore, the genotoxic and carcinogenic effects have only been observed at relatively high exposure rates. Current epidemiological and experimental studies are attempting to elucidate the mechanism of this action, pointing to the question whether arsenic is actually a true genotoxic, or rather an epigenetic carcinogen. Due to the complexity of its effects, both options remain plausible. Its interactions with other toxic substances still represent another important field of interest.
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Stress-strength interference-based importance for series systems considering common cause failure
Ocena opartej na modelu obciążeniowo-wytrzymałościowym ważności elementów systemu szeregowego z uwzględnieniem uszkodzeń wywołanych wspólną przyczyną
Autorzy:
Yu, Guangwei
Du, Yanwei
Yan, Li
Ren, Fangyu
Tematy:
importance measure
common cause failure
stress-strength interference
monotonicity analysis
component replacement
miara ważności
uszkodzenie wywołane wspólną przyczyną
model obciążeniowo-wytrzymałościowy
analiza monotoniczności
wymiana części
Pokaż więcej
Wydawca:
Polska Akademia Nauk. Polskie Naukowo-Techniczne Towarzystwo Eksploatacyjne PAN
Powiązania:
https://bibliotekanauki.pl/articles/301361.pdf  Link otwiera się w nowym oknie
Opis:
Series systems, whose structures are simple, are widely discovered in practical engineering, but the interdependency between the components is complex, such as common cause failure. With the consideration of the components’ strength, this paper focuses on ranking the importance measure of components considering the common cause failure based on the stress-strength interference (SSI) model. The weakest component can be identified by integrating the SSI model with the importance measure when the strength mean and variance of the component under the load stress is known. Firstly, the analytic methods are proposed to calculate the SSI-based importance of components in the series systems. Then, the monotonicity of SSI-based importance is analyzed by changing the strength mean or strength variance of one component. The results show that the SSI-based importance of components, whose parameters are changed, will reduce monotonically with the increase of strength mean or increase monotonically with the increase of strength variance. Finally, a component replacement method is developed based on the rules that both the importance of replaced component and the importance ranks should be unchanged after the replacement. SSI-based importance can help engineers to make maintenance decisions, and the component replacement method can increase the diversity of spare parts by finding the equivalent components.
Systemy szeregowe, które są szeroko stosowane w praktyce inżynieryjnej, charakteryzują się prostą strukturą, jednak współzależności między ich elementami są złożone, czego przykładem są uszkodzenia wywołane wspólną przyczyną. Rozważając wytrzymałości składowych systemu, opracowano metodę szeregowania miar ważności składowych z uwzględnieniem uszkodzeń wywołanych wspólną przyczyną. Metoda ta pozwala zidentyfikować najsłabsze ogniwo systemu. Miarę istotności zintegrowano z modelem obciążeniowo-wytrzymałościowym (SSI), biorąc pod uwagę średnią i wariancję wytrzymałości elementu pod obciążeniem. W pierwszym kroku opracowano metody analityczne pozwalające na obliczanie opartej na SSI ważności elementów w systemach szeregowych. Następnie analizowano monotoniczność opartej na SSI ważności zmieniając średnią lub wariancję wytrzymałości jednego z elementów. Wyniki pokazują, że mierzona w oparciu o SSI ważność elementów, których parametry są zmieniane, maleje monotonicznie wraz ze wzrostem średniej wytrzymałości lub rośnie monotonicznie wraz ze wzrostem wariancji wytrzymałości. Na podstawie przeprowadzonych badań, opracowano metodę wymiany części, opartą na zasadzie polegającej na tym, że zarówno ważność zastąpionego elementu, jak i rangi ważności powinny pozostać niezmienione po wymianie. Możliwość określania ważności opartej na modelu SSI może pomóc inżynierom w podejmowaniu decyzji dotyczących konserwacji, zaś proponowana metoda wymiany elementów systemu pozwala zwiększyć różnorodność części zamiennych poprzez znalezienie równoważnych elementów.
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Development and challenges of ASEAN
Autorzy:
Gosh, Amrik
Kotaniemi, Antti
Yan, Li Chong
Skrzypek, Mikolaj
Tematy:
ASEAN
AEC
trade
military
economy
Strait of Malacca
Pokaż więcej
Wydawca:
Uniwersytet Gdański. Wydział Ekonomiczny
Powiązania:
https://bibliotekanauki.pl/articles/518272.pdf  Link otwiera się w nowym oknie
Opis:
The aim of this essay is to give an overview of the development of ASEAN and identify and present main challenges that the ASEAN is facing. ASEAN is a regional intergovernmental organization originally developed for promoting peace, stability and political and economic cooperation and integration in the region.24It is important to understand that although ASEAN is geographically small are, it forms a culturally complex region with different nations, religious beliefs, laws, trading standards, political systems and conflicts. Collectively ASEAN is the fourth‐largest exporting region in the world and it accounts for 7 per cent of global exports. The exports of its member states have diversified and while Vietnam specializes in textiles and apparel, Singapore and Malaysia export electronics. Thailand on the other hand is specializing in exporting vehicle parts and other member nations are exporting mainly natural resources such as palm oil, coal, cocoa and tin. Myanmar have large reserves of oil, gas, and minerals. About 25 percent of region’s export go to other ASEAN nations, and less than half of intraregional trade is going to NAFTA countries, while exports to European Union are rising rapidly. China is becoming increasingly important export market for many ASEAN countries. ASEAN has free‐trade agreements with Australia, China, India, Japan, New Zealand, and South Korea25. Major challenge for ASEAN member states is lowering tariffs and non‐tariff barriers and harmonize custom procedures26. If successful, AEC integration might transform the region into more competitive region among the global economy.
Celem niniejszego artykułu jest przedstawienie rozwoju ASEAN oraz określenie i przedstawienie głównych wyzwań stojących przed tym stowarzyszeniem. ASEAN jest regionalną organizacją międzyrządową pierwotnie założoną w celu promowania stabilności i współpracy politycznej i gospodarczej oraz integracji w regionie. ASEAN to region skomplikowany kulturowo z różnymi narodami, przekonaniami religijnymi, prawami, standardami handlowymi, systemami politycznymi i konfliktami. Obszar ASEAN jest czwartym pod względem wielkości eksportu regionem na świecie (7 procent globalnego eksportu). Eksport państw członkowskich jest zróżnicowany. Wietnam specjalizuje się w przemyśle tekstylnym i odzieżowym, Singapur i w Malezja w elektronicznym, Tajlandia specjalizuje się w eksporcie części pojazdów. Inne państwa członkowskie eksportują głównie surowce naturalne takie jak olej palmowy, węgiel, kakao i cyna. Myanmar posiada duże zasoby ropy, gazu i minerałów. Około 25 procent eksportu skierowana jest do innych państw ASEAN, a mniej niż połowa handlu trafia do krajów NAFTA. Eksport do Unii Europejskiej szybko wzrasta. Również Chiny stają się coraz ważniejszym rynkiem eksportowym dla wielu państw ASEAN. ASEAN ma umowy o wolnym handlu z Australią, Chinami, Indiami, Japonią, Nową Zelandią i Koreą Południową. Głównym wyzwaniem dla państw członkowskich ASEAN jest obniżenie taryf i barier pozataryfowych oraz harmonizacja procedur niestandardowych. Jeśli uda się to zrealizować, region może stać się jeszcze bardziej konkurencyjny.
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Research on the Critical Sizes for Detonation of Cube-shaped Transfer Charges
Autorzy:
Zhao, Xiang-run
Jin, Shi-xin
Huang, Jin-hong
Li, Chao-zhen
Yan, Li-wei
Tematy:
explosive train
transfer charge
shock wave sensitivity
minimum safe separation distance
Pokaż więcej
Wydawca:
Sieć Badawcza Łukasiewicz - Instytut Przemysłu Organicznego
Powiązania:
https://bibliotekanauki.pl/articles/358353.pdf  Link otwiera się w nowym oknie
Opis:
In order to obtain the minimum size, thickness and safe separation distance, for the cube-shaped transfer charges used in MEMS (micro-electromechanical system) explosive trains, an explosive train using a JO-9C(III) cube-shaped transfer charge was designed for experimental research. Detonation transfer experiments and detonation interruption experiments were conducted in turn. In initial experiments, the electric detonators were all in the armed position, but different thicknesses of the cube-shaped transfer charges were used. In the later experiments, the thickness of the transfer charges were unchanged, but the separation distances were different. The detonation path of the transfer charge under unsafe conditions was analyzed using the shock wave attenuation law. The results showed that the minimum thickness ranged from 0.2 mm to 0.4 mm, the minimum safe separation distance ranged from 0.4 mm to 0.6 mm; and the cube-shaped transfer charge is detonated by a shock wave from a steel gap rather than air clearance when the safe separation distance is less than the minimum threshold. The thickness design value of the cube-shaped transfer charge (JO-9C(III)) should not be less than 0.6 mm, and the safe separation distance design value of the MEMS explosive train should not be less than 1 mm.
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Transport carbon emissions reduction efficiency and economic growth: a perspective from nighttime lights remote sensing
Autorzy:
Yan, Yuxiang
Li, Jianing
Tematy:
transport
carbon emissions reduction
control of emissions
data envelopment analysis
nighttime lights
redukcja emisji dwutlenku węgla
światła nocne
teledetekcja
Pokaż więcej
Wydawca:
Polska Akademia Nauk. Czasopisma i Monografie PAN
Powiązania:
https://bibliotekanauki.pl/articles/27311799.pdf  Link otwiera się w nowym oknie
Opis:
The carbon emissions are essential for climate change and 26% of the world's carbon emissions are related to transport. But focusing only on fewer carbon emissions might be biased at times. In order to keep a balance between economic growth and carbon emissions reduction, this paper evaluated the performance of carbon control by considering the input factors and output factors together, which is more comprehensive and reliable. Firstly, this paper has calculated the transport carbon emissions reduction efficiency (TCERE) based on the model of super SBM with undesirable outputs. The input factors include capital stock, labor force and fossil energy consumption. And the output factors include gross domestic product and carbon dioxide emissions. Then the influencing factors of TCERE were analyzed using econometric models. The economic growth, transport structure, technology level and population density were posited as influencing factors. This paper creatively proposed the per capita nighttime lights brightness as a new indicator for economic growth. An empirical study was conducted in East China from 2013 to 2017, and this study has found that the relationship between TCERE and economic growth shows an U-shape. Besides, transport structure and technology level both show a positive impact on TCERE. The implications of our findings are that: (a) The TCERE declines slower in East China, giving us reason to believe that the improvement of TCERE is predictable; (b) When economic growth exceeds the turning point, economic growth is conducive to the improvement of TCERE. We could develop the economy boldly and confidently; (c) Increased investment in railway and waterway transportation infrastructure projects is needed to strengthen the structure of the railway and waterway transportation systems. Furthermore, the general public and businesses should be encouraged to prefer rail or river transportation; (d) Investment in scientific and technological innovation should be enhanced in order to produce more efficient energy-use methods.
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
An approach to suppress low-frequency oscillation in the hybrid multi-Infeed HVDC of mixed H2/H∞ robust-based control theory
Autorzy:
Li, Congshan
Liu, Yan
Li, Yikai
He, Ping
Fang, Yan
Sheng, Tingyu
Tematy:
additional damping controller
CSP
HMIDC
LFO
mixed 2/∞ control
TLS-ESPRIT
Pokaż więcej
Wydawca:
Polska Akademia Nauk. Czytelnia Czasopism PAN
Powiązania:
https://bibliotekanauki.pl/articles/2042784.pdf  Link otwiera się w nowym oknie
Opis:
A hybrid multi-infeed HVDC (HMIDC) system is composed of line-commutated converter-based high-voltage direct current (LCC-HVDC) and voltage-source converterbased high-voltage direct current (VSC-HVDC), whose receiving ends have electrical coupling. To solve the problem of low-frequency oscillation (LFO) caused by insufficient damping in the HMIDC system, according to the multi-objective mixed 2/∞ output feedback control theory with regional pole assignment, an additional robust damping controller is designed in this paper, which not only has good robustness, but also has strong adaptability to the change of system operation mode. In the paper, the related oscillation modes and transfer function of the controlled plant are obtained, which are identified by the total least squares estimation of signal parameters via rotary invariance technology (TLS-ESPRIT). In addition, the control-sensitive point (CSP) for suppressing LFO based on the small disturbance test method is determined, which is suitable for determining the installation position of the controller. The results show that the control sensitivity factor of VSC-HVDC is greater than that of LCC-HVDC so that adding an additional damping controller to VSC-HVDC is better than LCC-HVDC in suppressing the LFO of HMIDC. Finally, a hybrid double infeed DC transmission system with three receiving terminals is built on PSCAD/EMTDC where the time-domain simulations are performed to verify the correctness of the CSP selection and the effectiveness of the controller.
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Design and mechanical analysis of a composite T-type connection structure for marine structures
Autorzy:
Li, Xiaowen
Zhu, Zhaoyi
Li, Yan
Hu, Zhe
Tematy:
T-type connection structure
composite structure design
test
mechanical analysis
marine structure
Pokaż więcej
Wydawca:
Politechnika Gdańska. Wydział Inżynierii Mechanicznej i Okrętownictwa
Powiązania:
https://bibliotekanauki.pl/articles/260625.pdf  Link otwiera się w nowym oknie
Opis:
A new T-type connection structure consisting of composite sandwich plates, reinforced cores and adhesive was proposed for the construction of lightweight ships to resolve connection problems between bulkheads and decks of composite lightweight ship superstructures. Based on the design principles and mechanical properties of composite structures, the mechanical behaviour of the structure under a dangerous loading condition was investigated. In addition, the ultimate bearing capacities and damage modes were examined, the results of which demonstrated that the strength of the structure is weak, and that the adhesive and reinforced core between the face plate and the web plate is the primary weakness of the structure. A numerical simulation method was verified using the results of the mechanical tests, and five characteristic paths at the connection area were established. The stresses and displacements along the five paths were calculated using the numerical method. Then, variations in the geometric parameter and the strength and weight of the connection were summarised. The optimal angle of the adhesive bonding area is approximately 60°, which supports the optimal design and practical application of the lightweight ship adhesive-bonded connection structure.
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Acoustic Matching Characteristics of Annular Piezoelectric Ultrasonic Sensor
Autorzy:
Li, Haoran
Hu, Yan
Li, Laibo
Xu, Dongyu
Tematy:
piezoelectric ceramics
ultrasonic sensors
acoustic matching characteristics
Pokaż więcej
Wydawca:
Polska Akademia Nauk. Czytelnia Czasopism PAN
Powiązania:
https://bibliotekanauki.pl/articles/2141675.pdf  Link otwiera się w nowym oknie
Opis:
Using intelligent materials and sensors to monitor the safety of concrete structures is a hot topic in the field of civil engineering. In order to realize the omni-directional monitoring of concrete structural damage, the authors of this paper designed and fabricated an embedded annular piezoelectric ultrasonic sensor using the annular piezoelectric lead zirconate titanate (PZT) ceramic as a sensing element and epoxy resin as the matching and the backing layers. The influence of different matching and backing layers thickness on the acoustic characteristic parameters of the sensor were studied. The results show that the resonant frequency corresponding to the axial mode of annular piezoelectric ceramics moves toward the high frequency direction with the decrease of the height of piezoelectric ceramics, and the radial vibration mode increases as well as the impedance peak. With the thickness of the backing layer increases from 1 mm to 2 mm, the radial resolution of the annular piezoelectric ultrasonic sensor is enhanced, the pulse width is reduced by 39% comparing with the sensors which backing layer is 1 mm, and the head wave amplitude and −3 dB bandwidth are increased by 61% and 66%, respectively. When the matching layer thickness is 3 mm, the sensor has the highest amplitude response of 269 mV and higher sensitivity.
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Research on regional emergency DC power support strategy of VSC-MTDC transmission system
Autorzy:
Li, Congshan
Sheng, Tingyu
Fang, Yan
Li, Yikai
Tematy:
coordinated control
dynamic active power support
emergency DC power support
VSC-MTDC
skoordynowana kontrola
dynamiczne wspomaganie mocy czynnej
awaryjne wsparcie zasilania prądem stałym
Pokaż więcej
Wydawca:
Polska Akademia Nauk. Czytelnia Czasopism PAN
Powiązania:
https://bibliotekanauki.pl/articles/1841327.pdf  Link otwiera się w nowym oknie
Opis:
In the asynchronous interconnected power grid that is composed of the multiterminal voltage-source converter high voltage direct current (VSC-MTDC) system, the control methods of each converter station and the frequency of the connected AC systemare not the same. When a fault occurs in any place of the asynchronous interconnected system, it will cause the system to have power shortage or surplus, affecting the safe and stable operation of the interconnected power grid. In order to solve the problem of insufficient regional active power reserve, based on the VSC-MTDC asynchronous regional interconnection system and the principle of regional sharing, the dynamic power controller under disturbance conditions is established, and the controller parameters are set to achieve the accuracy of unbalanced power in the disturbance area measuring. Then, according to the degree of the disturbance power, considering the factors that affect the support effect of the converter station, an emergency DC power support (EDCPS) scheme under different power disturbances is formulated to achieve power compensation for the disturbance area. Basedon PSCAD/EMTDC software, the proposed control strategy is simulated. The result showst hat the converter station closer to the disturbance area has a better support effect, and the dynamic active power controller can timely and accurately deliver to the disturbance area when the active power reserve is insufficient.
Dostawca treści:
Biblioteka Nauki
Artykuł

Ta witryna wykorzystuje pliki cookies do przechowywania informacji na Twoim komputerze. Pliki cookies stosujemy w celu świadczenia usług na najwyższym poziomie, w tym w sposób dostosowany do indywidualnych potrzeb. Korzystanie z witryny bez zmiany ustawień dotyczących cookies oznacza, że będą one zamieszczane w Twoim komputerze. W każdym momencie możesz dokonać zmiany ustawień dotyczących cookies