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1
Content available Production of (R)-styrene oxide by recombinant whole-cell biocatalyst in aqueous and biphasic system
Xue F., Gao J.
Polish Journal of Chemical Technology
|
2018
|
Vol. 20, nr 2
54--60
EN
The enantioselective resolution of racemic styrene oxide (rac-SO) to (R)-SO by whole cells of a recombinant Escherichia coli expressing epoxide hydrolase (EH) activity in aqueous and biphasic system were studied. Some parameters that may alter this bio-resolution, such as the concentration of recombinant cell, substrate and product were evaluated. The effect of the addition of different additives on the course of rac-SO biotransformation was also investigated. The results showed that the yield and the enantiomeric excess (ee) of (R)-SO were dependent on these variables. When the kinetic resolution was conducted with 350 mM of rac-SO, enantiopure (R)-SO with high (≥99%) ee was obtained with a yield of 38.2% yield at 12.2 h in the presence of 10% (v/v) Tween 80. An isooctane/aqueous system was developed to overcome the adverse factors in the aqueous phase, resulting in an improvement of yield from 38.2% to 42.9%. The results will provide a useful guidance for further application of this enzyme in the biocatalytic production of chiral synthons.
2
Content available Truncated two-stage compound parabolic concentrator for collecting human diffuse transmission light
Gao J., Han G., Lu Q., Ding H., Xu J., Sun J.
Optica Applicata
|
2018
|
Vol. 48, nr 2
325--335
EN
We propose an optical system employing a compound parabolic concentrator for near infrared spectroscope in noninvasive blood components testing. A truncated two-stage compound parabolic concentrator system is designed, which consists of a normal first-stage compound parabolic concentrator and a truncated second-stage compound parabolic concentrator. Using advanced ray tracing technique, the optical efficiencies of truncated two-stage compound parabolic concentrator system, ellipsoidal mirror system and non-optical-focusing mirror system are calculated to be 25.4%, 22.4% and 4.0%, respectively. Furthermore, the total length of truncated two-stage compound parabolic concentrator is only about 68 mm while the ellipsoidal mirror is 110 mm. It indicates that the truncated two-stage compound parabolic concentrator system enhances the ability of concentrating human diffuse transmission light, and it is a benefit to improve signal-to-noise ratio of noninvasive biochemical analysis system efficiently. Due to the advantage of small size, it tends to achieve a miniature instrument.
3
Content available Life prediction for LY12CZ notched plate based on the continuum damage mechanics and the genetic algorithm and radial basis function method
Gao J., Li P.
Journal of Theoretical and Applied Mechanics
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2018
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Vol. 56 nr 4
1109--1122
EN
In this paper, a new method based on the Continuum Damage Mechanics (CDM) and the Genetic Algorithm and Radial Basis Function neural network method (GARBF) is proposed to predict fatigue life of LY12CZ notched plate. Firstly, the multiaxial fatigue damage evolution equation is derived, and the fatigue life of the notched specimen is predicted based on the CDM method. Secondly, the RBF method is introduced to modify the relative deviation between the theoretical result and actual life. According to the drawbacks of the RBF method, the GA is adopted to optimize network parameters to effectively improve the model quality and reduce the training error. Then, the verification test indicates that the combined method of CDM and GARBF is able to reduce the average relative error of the results of fatigue life prediction to about 7%, which shows that the new method to predict the fatigue life is more reliable. At last, compared with the predicted results of the traditional Back Propagation (BP) neural network, the GARBF model proposed in this paper has a better optimization effect and the result is more stable. This research provides a feasible way to predict the fatigue lives of the notched plate based on the CDM and GARBF method.
4
Content available remote Efficient Computation of Palindromes in Sequences with Uncertainties
Alzamel M., Gao J., Iliopoulos C.S., Liu C.
Fundamenta Informaticae
|
2018
|
Vol. 163, nr 3
253--266
EN
In this work, we consider a special type of uncertain sequence called weighted string. In a weighted string every position contains a subset of the alphabet and every letter of the alphabet is associated with a probability of occurrence such that the sum of probabilities at each position equals 1. Usually a cumulative weight threshold 1/z is specified, and one considers only strings that match the weighted string with probability at least 1/z. We provide an O(nz)-time and O(nz)-space off-line algorithm, where n is the length of the weighted string and 1/z is the given threshold, to compute a smallest maximal palindromic factorization of a weighted string. This factorization has applications in hairpin structure prediction in a set of closely-related DNA or RNA sequences. Along the way, we provide an O(nz)-time and O(nz)-space off-line algorithm to compute maximal palindromes in weighted strings. Finally, we provide an experiment of our proposed algorithm.
5
Content available Application of Improved Robust Kalman Filter in Data Fusion for PPP/INS Tightly Coupled Positioning System
Li Z., Yao Y., Wang J., Gao J.
Metrology and Measurement Systems
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2017
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Vol. 24, nr 2
289--301
EN
A robust Kalman filter improved with IGG (Institute of Geodesy and Geophysics) scheme is proposed and used to resist the harmful effect of gross error from GPS observation in PPP/INS (precise point positioning/inertial navigation system) tightly coupled positioning. A new robust filter factor is constructed as a three-section function to increase the computational efficiency based on the IGG principle. The results of simulation analysis show that the robust Kalman filter with IGG scheme is able to reduce the filter iteration number and increase efficiency. The effectiveness of new robust filter is demonstrated by a real experiment. The results support our conclusion that the improved robust Kalman filter with IGG scheme used in PPP/INS tightly coupled positioning is able to remove the ill effect of gross error in GPS pseudorange observation. It clearly illustrates that the improved robust Kalman filter is very effective, and all simulated gross errors added to GPS pseudorange observation are successfully detected and modified.
6
Content available Operation reliability analysis based on fuzzy support vector machine for aircraft engines
Gao J., Wang H.
Eksploatacja i Niezawodność
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2015
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Vol. 17, no. 2
186--193
EN
The aircraft engine is a complex and repairable system, and the diversity of its failure modes increases the difficulty of operation reliability analysis. It is necessary to establish a dynamic relationship among monitoring information, failure mode and system reliability for achieving scientific reliability analysis for aircraft engines. This paper has used fuzzy support vector machine (FVSM) method to fuse condition monitoring information. The reliability analysis models including Gamma process model and Winner process model, respectively for different failure modes, have been presented. Furthermore, these two models have been integrated on the basis of competing failures’ mechanism. Bayesian model averaging has been used to analyze the effects of different failure modes on aircraft engines’ reliability. As a result of above, the goal of an accurate analysis of the reliability for aircraft engines has been achieved. Example shows the effectiveness of the proposed model.
PL
Silnik samolotu to złożony system naprawialny, a różnorodność przyczyn jego uszkodzeń zwiększa trudność analizy niezawodności eksploatacyjnej. Istnieje konieczność ustalenia dynamicznych związków pomiędzy monitorowaniem informacji, przyczynami uszkodzeń i niezawodnością systemu, których znajomość pozwoliłaby przeprowadzać naukową analizę niezawodności silników lotniczych. Do integracji danych z monitorowania informacji, w pracy wykorzystano metodę rozmytej maszyny wektorów nośnych (FSVM). Dla różnych przyczyn uszkodzeń, przedstawiono odpowiednie modele analizy niezawodności – model procesu Gamma i model procesu Wienera. Przedstawione modele zintegrowano na podstawie mechanizmu uszkodzeń konkurujących. Do analizy wpływu różnych przyczyn uszkodzeń na niezawodność silników lotniczych wykorzystano procedurę bayesowskiego uśredniania modeli. Dzięki powyższym krokom, osiągnięto założony cel dokładnej analizy niezawodności silników samolotowych. Przykład pokazuje skuteczność proponowanego modelu.
7
Content available remote Responses to UV-B exposure by saplings of the relict species Davidia involucrata Bill are modified by soil nitrogen availability
Li Y., Gao J., Zhang L., Su Z.
Polish Journal of Ecology
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2014
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Vol. 62, nr 1
101--110
EN
Climate change scenarios suggest that plants will be exposed to increasing levels of ultraviolet radiation in the future. The dove tree, Davidia involucrata Bill (Davidiaceae) is a rare and endangered tree species in China. Its distribution is predicted to become more montane as the climate warms, exposing it to higher levels of UV-B and different soil conditions. We compared the effects of glasshouse ambient (7.08 uW cm-2) and increased (13.93 uW cm-2) UV-B on survivorship, secondary metabolites indicative of radiation damage, and putative defensive responses of Davidia involucrata saplings growing under current and increased nitrogen conditions (5 and 25 g m-2 a-1 N). Mortalities were higher among plants exposed to increased UV-B, but only in soils with high supplementary nitrogen. Increases in compounds associated with defense against radiation were more frequently recorded under high supplementary nitrogen conditions. This rare and localised plant is highly sensitive to elevated UV-B when growing in high nitrogen soils, a combination that is likely to increase in the summer.
8
Content available A reliability evaluation study based on competing failures for aircraft engines
Wang H., Gao J.
Eksploatacja i Niezawodność
|
2014
|
Vol. 16, no. 2
171--178
EN
Aircraft engine is a complex and repairable system, and the diversity of its failure modes increases the difficulty of reliability evaluation. It is necessary to establish a dynamic relationship among data, failure mode and system reliability, to achieve the scientific reliability evaluation for aircraft engines. This paper has used data fusion method to establish reliability evaluation models respectively for performance degradation failures and sudden failures. Furthermore, these two models have been integrated on the basis of competing failures’ mechanism. Bayesian model averaging has been used to analyze the impacts of performance degradation failures and sudden failures on aircraft engines’ reliability. As a result of above, the goal of an accurate evaluation of the reliability for aircraft engines has been achieved. Example shows the effectiveness of the proposed model.
PL
Silnik samolotu to złożony system naprawialny, w którym różnorodność przyczyn uszkodzeń zwiększa trudność oceny niezawodności. Dlatego też istnieje konieczność ustalenia dynamicznych związków pomiędzy danymi, przyczynami uszkodzenia i niezawodnością systemu, których znajomość pozwoliłaby przeprowadzać naukową ocenę niezawodności silników lotniczych. W prezentowanej pracy wykorzystano metodę fuzji danych do opracowania modeli oceny niezawodności w zakresie uszkodzeń wynikających z obniżenia charakterystyk oraz uszkodzeń nagłych. Ponadto, opracowane modele zintegrowano na podstawie mechanizmu uszkodzeń konkurujących. Do analizy wpływu dwóch omawianych typów uszkodzeń na niezawodność silników lotniczych wykorzystano procedurę bayesowskiego uśredniania modeli. Dzięki powyższym krokom, osiągnięto założony cel dokładnej oceny niezawodności silników samolotowych. Przykład pokazuje skuteczność proponowanego modelu.
9
Content available remote Research on Objection Information Extraction Arithmetic in Photo-electric Detection Target Base on Wavelet Analysis Method
Li H., Lei Z., Wang Z., Gao J.
Przegląd Elektrotechniczny
|
2012
|
R. 88, nr 9b
157-161
EN
To improve measurement precision and solve the question on projectile information extraction when projectile go through detection screen of photoelectric detection target, the wavelet analysis method was applied to process its information and look for its starting time in screen. The detection principle of photoelectric detection target was analyzed, the characteristic of wavelet analysis method and LMS adaptive filtering algorithm were used to research and analyze the output signal of photoelectric detection target. According to the output signal characteristic of photoelectric detection target, the wavelet transform modulus maxima theory and singularity position point were applied to search out signal’s start moment that projectile flying through detection screen, and ensure start moment and calculate time value between detection screens. Base on test velocity principle and experimentation, wavelet analysis method is compared with the traditional nose trigger extraction method, the precision of measuring velocity is less than 0.2%, which verifies wavelets analysis method to extract the photoelectric detection target detection information is feasible and correct.
PL
W artykule analizowane są metody analizy obrazu detekcji fotoelektrycznej w przypadku poruszającego się szybko obiektu, takiego jak n. pocisk. Do analizy wykorzystano transformatę falkową oraz algorytm filtrowania LMS.
10
Content available Improved linear complexities of the frequency hopping sequences in two optimal sets
Gao J., Li X., Wei Y.
Control and Cybernetics
|
2012
|
Vol. 41, no. 2
317-334
EN
For the anti-jamming purpose, high linear complexity is desired for each frequency hopping sequence in an optimal set. Using a proper power permutation, Wang has shown that an optimal set of frequency hopping sequences with small linear complexity can be transformed into a new optimal set of frequency hopping sequences with large linear complexity. This paper conains two results. First, we extend the result of Wang. A power permutation is only suitable for a special construction of optimal set of frequency hopping sequences, see Wang (2011). However, the power permutation chosen in this paper applies to the general construction of optimal set of frequency hopping sequences. Second, by using a binomial permutation polynomial P(x), which is different from those permutations used before, we obtain a novel optimal set of frequency hopping sequences with high linear complexity from an optimal set of frequency hopping sequences with small linear complexity. By counting the number of different roots in the sequence representation, we determine the linear complexities of the frequency hopping sequences in two optimal sets transformed by the power permutation or binomial permutation.
11
Content available Optymalna alokacja zapewniająca bezpieczeństwo w układach procesowych oparta na przepływach sieciowych
Han Z., Gao J.
Eksploatacja i Niezawodność
|
2011
|
nr 1
27-34
PL
Bezpieczeństwo stanowi w inżynierii procesowej czynnik krytyczny, o którym należy pamiętać podczas całego czasu eksploatacji układów procesowych. W niniejszym artykule przedstawiono nową metodę optymalnej alokacji zasobów, opartą na przepływach w sieci, mającą zapewnić bezpieczeństwo układów procesowych. Istniejące optymalne alokacje zasobów wspierające bezpieczeństwo opierają się na rozwiązaniach fizycznych (np. unowocześnianiu podstawowych elementów wyposażenia i wbudowywaniu nadmiarowości) nieodpowiednich dla układów procesowych, które ulegają częstym awariom. Takie rozwiązania pociągają za sobą konieczność częstych alokacji fizycznych, które poważnie zakłócają normalne działanie całego układu. Dodatkowo, metody fizyczne stosuje się tylko wtedy, kiedy uszkodzenia układu nawarstwią sie do pewnego stopnia. Stan układu procesowego w inżynierii chemicznej często ulega wahaniom z powodu wielu czynników, takich jak niekontrolowane uwolnienie energii czy użycie niejednolitych materiałów produkcyjnych. Częste wahania mogą prowadzić do awarii układu. Konieczna jest zatem umiejętność unikania akumulacji błędów poprzez kontrolę wahań i stabilizację stanu układu, co prowadzi do zapewnienia bezpieczeństwa układu procesowego. W niniejszej pracy przedstawiamy metodę optymalnej alokacji, opartą na przepływach w sieci, która umożliwia osiągnięcie powyższego celu. Wedle nowej metody, przepływy osiągalne konstruuje się na podstawie przepływów w sieci układu, stanu wyposażenia układu oraz wymagań procesu. Wzory rozwiązań dla zmiennych stanu konstruowanych przepływów osiągalnych dają wartości korygujące, które używane są do kontrolowania wahań systemu i stabilizacji jego stanu. Prezentowane studium przypadku demonstruje możliwe zastosowania i efektywność proponowanej metody.
EN
Safety is a critical factor to be considered throughout the entire lifetime of process systems in process engineering. This paper presents a novel optimal resource allocation method based on network flows for assuring the safety of process systems. Existing optimal resource allocations for safety mainly depend on physical ways (for example, updating core equipments, and incorporating redundancies), which are not suitable for process systems experiencing frequent malfunctions. As a result, frequent physical allocations are needed, which severely interrupt the normal operation of the entire system. In addition, the physical methods are applied only when system faults accumulate to some extent. The state of a process system in chemical engineering often dithers due to many factors such as uncontrollable energy release and inconsistent production of materials. The frequent dithering can lead to the system failure. It is necessary to be able to avoid the accumulation of errors by controlling the dithering and stabilizing the system state, thus assuring the safety of the process system. In this paper, we propose a network flow-based optimal allocation method to achieve the above goal. Feasible flows will be constructed based on the system’s network flow, system equipment status, and process requirements. The solution formulas to the state variables of the constructed feasible flows give the adjustment values, which are used to control the dithering of the system, thus stabilize the system state. A case study is given to show the application and effectiveness of the proposed method.
12
Content available Optimal resource allocation for safety in distributed complex electromechanical systems
Han Z., Gao J., Xing L., Chen F.
Eksploatacja i Niezawodność
|
2011
|
nr 2
4-12
EN
Existing optimal resource allocation for system safety mainly concentrates on series/parallel systems or systems that can be converted into series/parallel models. However, for some distributed complex electromechanical systems, it is very difficult or even impossible to refine them into a series/parallel model; in addition, the safety of some system units is immeasurable because of the coupling relationship complexity in the system composition structure. In this paper, a novel method based on complex networks and path set-based dynamic programming is proposed for the optimal resource allocation for maximal safety of distributed complex electromechanical systems with non-series-parallel structures. As a measurement of the system safety, safety importance is defined, which is a function of two safety feature parameters - accident loss and accident probability. A practical system is taken as an example to illustrate and verify the feasibility and applicability of the proposed method.
PL
Istniejące strategie optymalnej alokacji zasobów służące zapewnieniu bezpieczeństwa systemów skupiają się głównie na systemach szeregowo-równoległych lub na systemach, które można przekształcić w modele szeregowo-równoległe. Jednakże, w przypadku niektórych złożonych rozproszonych systemów elektromechanicznych, przetworzenie na model szeregowo-równoległy może być bardzo trudne lub wręcz niemożliwe. Dodatkowo, z powodu złożoności relacji sprzężeń w fizycznej strukturze tego rodzaju systemów, bezpieczeństwo niektórych jednostek systemowych jest niemierzalne. W niniejszym artykule przedstawiono nową metodę optymalnej alokacji zasobów gwarantującą maksymalne bezpieczeństwo złożonych rozproszonych systemów elektromechanicznych o strukturze innej niż szeregowo-równoległa. Metoda ta oparta jest na sieciach złożonych i wykorzystuje dynamiczne programowanie bazujące na zbiorach ścieżek. Jako miarę bezpieczeństwa systemu zastosowano pojęcie hierarchii bezpieczeństwa, zdefiniowane jako funkcja dwóch parametrów bezpieczeństwa: strat z tytułu awarii oraz prawdopodobieństwa awarii. Dla zilustrowania proponowanej metody i weryfikacji jej przydatności i możliwości zastosowania, przedstawiono przykład rzeczywistego systemu.
13
Content available remote Jacket effect on strain measurement accuracy for distributed strain sensors based on Brillouin scattering
Ding Y., Shi B., Bao X., Gao J.
Optica Applicata
|
2006
|
Vol. 36, nr 1
57-67
EN
Fiber jacket has a function of protecting fibers from harsh environment; it also has an impact on the measured strain accuracy. In this paper, we report on our study of jacket effect to distributed Brillouin sensor system on strain measurement accuracy for constant load stretching and constant length stretching using the 900 m tight-buffered fiber (Type-A) and the 250 m optical fiber (Type-B). We have studied the time-varying performance under the stretching of constant load and length. It was found that, within 48 hours under constant load stretching, the strain value of the Type-A measured by BOTDR (Brillouin optical time-domain reflectometer) increased with time, while the Type-B it kept stable. Within 48 hours under constant length stretching, the strain value of the Type-A decreased with time, while the Type-B it kept stable. After relaxation, the strain value of the Type-B reached zero within 1 hour, while the Type-A declined gradually. We found the creep deformation and stress relaxation of jacket to be the leading cause to this phenomena.
14
Novel mi-X Bridged Dicopper(II) Complex System : Synthesis, Structural Characterization and Catalytic Activity
Gao J., Zhong S. H.
Polish Journal of Chemistry
|
2001
|
Vol. 75, nr 3
379-385
EN
Three NAPH (1,8-naphthalate dianion) bridged dicopper(II) complexes have been synthesized, namely [NAPHCu2(_-X)2_2H2O]_nH2O, X = OH- (1), OAc- (2) and Cl- (3). NAPH was found to have the ability to form a dinuclear core with _-X as additional ligand. Based on IR, elemental analysis and electronic spectra, these complexes were found to have heterocyclic structure with both NAPH and _-X as bridging ligands. The temperature dependence of magnetic susceptibilities of 1 has been studied, giving the exchange integral of J = -216 cm-1, g = 2.09. This result is in agreement with proposed dihydroxo-bridged structure of 1, since Cu2O2 unit normally undergoes a strong antiferromagnetic interaction. Significantly, these complexes were found to exhibit catalase- like activity.
15
mi-phth-mi-X Bridged Dicobalt(II) Complexes : Synthesis, properties and Catalase-Like Activity
Gao J.
Polish Journal of Chemistry
|
2001
|
Vol. 75, nr 9
1203-1208
EN
ž-phth (phthalic acid dianion), having two isolated metal-binding groups, together with X ligand (X = CH3CO2 _, CF3 CO2 _ and Ph-CO2 _ ) formed dicobalt(II) complexes [Co2(II)(ž-phth)(ž-CH3CO2 _ )(bipy)2]ClO4 (1), [Co2(II)(ž-phth)(ž-CF3CO2 _ )(bipy)2]ClO4 (2) and [Co2(II)(ž-phth)(ž-Ph-CO2 _ )(bipy)2]ClO4 (3). Their structure was characterized spectroscopically and magnetically, presenting a ž-phth-ž-X-bridged dinuclear structure. The pair of cobalt ions bridged by CH3COO undergoes antiferromagnetic coupling. Catalytic properties for H2O2 dismutation are reported for complex 1-3.
16
Synthesis and Magnetism of Nickel(II) Binuclear Complexes with Oxamide-N,N'-diacetic Acid
Han K., Tian Z., Wei K., Ma S., Lu L., Meng X., Yang X., He M., Gao J.
Polish Journal of Chemistry
|
1999
|
Vol. 73, nr 9
1451-1456
EN
Three novel -oxamidato binuclear complexes have been synthesized. The temperature dependences of the magnetic susceptibilities. These results are commensurate with antiferromagnetic interaction between the adjacent metal ions.
17
New antiferromagnetic dinuclear complexes of manganese(II) with 1,8-naphthalato as bridging ligand: synthesis, spectrum and magnetism
Gao J., Ma S.L., Liao D.Z.
Polish Journal of Chemistry
|
1998
|
Vol. 72, nr 5
839-843
EN
Three manganese(II) binuclear complexes have been synthetized, namely [Mn2(NAPH)(L)4(ClO4)2, L is bpy(2,2'-bipyridyl), phen(1,10-phenanthroline) or NO2-phen(5-nitro-1,10-phenanthroline), NAPH denotes the 1,8-naphthalate dianion. Based on IR, elemental analyses nd conductivity measurement, these complexes are proposed to have extended NAPH-bridges structures and consist of two manganese(II) in a distorted octahedron environment. The temperature dependence of magnetic susceptibilities of manganese(II) complexes have been studied, giving the exchange integral J=-0.36 cm-1 (bpy); J=-0.49 cm-1 (phen), respectively. These results indicate a weak antiferromagnetic coupling between the paramagnetic ions in the complexes.
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