A new optimization method for the optimization of stacking of composite glass fiber laminates is developed. The fiber orientation and angle of the layers of the cylindrical shells are sought considering the buckling l...A new optimization method for the optimization of stacking of composite glass fiber laminates is developed. The fiber orientation and angle of the layers of the cylindrical shells are sought considering the buckling load. The proposed optimization algorithm applies both finite element analysis and the mode-pursuing sampling （MPS）method. The algorithms suggest the optimal stacking sequence for achieving the maximal buckling load. The procedure is implemented by integrating ANSYS and MATLAB. The stacking sequence designing for the symmetric angle-ply three-layered and five-layered composite cylinder shells is presented to illustrate the optimization process, respectively. Compared with the genetic algorithms, the proposed optimization method is much faster and efficient for composite staking sequence plan.展开更多
A method to improve the low-velocity impact performance of composite laminate is proposed, and a multi-island genetic algorithm is used for the optimization of composite laminate stacking sequence under low-velocity i...A method to improve the low-velocity impact performance of composite laminate is proposed, and a multi-island genetic algorithm is used for the optimization of composite laminate stacking sequence under low-velocity impact loads based on a 2D dynamic impact finite element analysis. Low-velocity impact tests and compression-after impact（CAI） tests have been conducted to verify the effectiveness of optimization method. Experimental results show that the impact damage areas of the optimized laminate have been reduced by 42.1% compared to the baseline specimen, and the residual compression strength has been increased by 10.79%, from baseline specimen 156.97 MPa to optimized 173.91 MPa. The tests result shows that optimization method can effectively enhance the impact performances of the laminate.展开更多
Wind and solar energy are two popular forms of renewable energy used in microgrids and facilitating the transition towards net-zero carbon emissions by 2050.However,they are exceedingly unpredictable since they rely h...Wind and solar energy are two popular forms of renewable energy used in microgrids and facilitating the transition towards net-zero carbon emissions by 2050.However,they are exceedingly unpredictable since they rely highly on weather and atmospheric conditions.In microgrids,smart energy management systems,such as integrated demand response programs,are permanently established on a step-ahead basis,which means that accu-rate forecasting of wind speed and solar irradiance intervals is becoming increasingly crucial to the optimal operation and planning of microgrids.With this in mind,a novel“bidirectional long short-term memory network”(Bi-LSTM)-based,deep stacked,sequence-to-sequence autoencoder(S2SAE)forecasting model for predicting short-term solar irradiation and wind speed was developed and evaluated in MATLAB.To create a deep stacked S2SAE prediction model,a deep Bi-LSTM-based encoder and decoder are stacked on top of one another to reduce the dimension of the input sequence,extract its features,and then reconstruct it to produce the forecasts.Hyperparameters of the proposed deep stacked S2SAE forecasting model were optimized using the Bayesian optimization algorithm.Moreover,the forecasting performance of the proposed Bi-LSTM-based deep stacked S2SAE model was compared to three other deep,and shallow stacked S2SAEs,i.e.,the LSTM-based deep stacked S2SAE model,gated recurrent unit-based deep stacked S2SAE model,and Bi-LSTM-based shallow stacked S2SAE model.All these models were also optimized and modeled in MATLAB.The results simulated based on actual data confirmed that the proposed model outperformed the alternatives by achieving an accuracy of up to 99.7%,which evidenced the high reliability of the proposed forecasting.展开更多
This study tried to explore the ground movement induced by triple stacked tunneling(TST) with different construction sequences. A case study in Tianjin, China was used to investigate the ground movement during the TST...This study tried to explore the ground movement induced by triple stacked tunneling(TST) with different construction sequences. A case study in Tianjin, China was used to investigate the ground movement during the TST(upper tunneling(UT)). For this, a modified Peck formula was proposed to predict the surface settlement induced by TST. Next, three sets of finite element analyses(FEA) were used to compare the effects of construction sequences(i.e. UT, middle tunneling(MT), and lower tunneling(LT)) on vertical and lateral ground displacements. The results of Tianjin case and UT reveal that compared to a Gaussian distribution for a single tunnel, the surface settlement curve of triple stacked tunnels is a bimodal distribution. It seems that the proposed modified Peck formula can effectively predict the surface settlement induced by TST. The results of the three sets of FEA demonstrate that the construction sequence has a significant influence on the ground movement. Among the three construction sequences, the largest lateral displacement is observed in the MT and the smallest one in UT.The existing tunnel has an inhibitory effect on the vertical displacement. The maximum value of the lateral displacement occurs at the depth of the new tunnel in each construction sequence.展开更多
A comprehensive understanding of the relevance between molecular structure and passivation ability to screen efficient modifiers is essential for enhancing the performance of perovskite solar cells(PSCs).Here,three si...A comprehensive understanding of the relevance between molecular structure and passivation ability to screen efficient modifiers is essential for enhancing the performance of perovskite solar cells(PSCs).Here,three similarπ-πstacking molecules namely benzophenone(BPN),diphenyl sulfone(DPS),and diphenyl sulfoxide(DPSO)are used as back-interface modifiers in carbon-based CsPbBr_(3)PSCs.After investigation,the results demonstrate the positive effect of the p-πconjugation characteristic inπ-πstacking molecules on maximizing their passivation ability.The p-πco njugation of DPSO enables a higher coordinative activity of oxygen atom in its S=O group than that in 0=S=O group of DPS and C=O group of BPN,which gives a superior passivation effect of DPSO on defects of perovskite films.The modification of DPSO also significantly improves the p-type behavior of perovskite films and the back-interfacial energetics matching,inducing an increase of hole extraction and a decrease of energy loss.Finally,the unencapsulated carbon-based CsPbBr_(3)PSCs with DPSO achieve a maximum power conversion efficiency of 10.60%and outstanding long-term stability in high-temperature,high-humidity(85℃,85%relative humidity)air environment.This work provides insights into the influence of the structure ofπ-πstacking molecules on their ability to improve the perovskite films quality and therefore the PSCs performance.展开更多
Tannases produced by filamentous fungi are in a family of important hydrolases of gallotannins and have broad industry applications.But until now,the 3-D structures of fungi tannases have not been reported.The protein...Tannases produced by filamentous fungi are in a family of important hydrolases of gallotannins and have broad industry applications.But until now,the 3-D structures of fungi tannases have not been reported.The protein sequence deduced from the cDNA sequence obtained using RT-PCR amplification was identified as tannase through sequence alignment and phylogenetic analysis.Structure models based on the tannase sequence were collected using I-TASSER,and the model with the best match to the surface charge density-pH titration profile was selected as the final structure for tannase from Aspergillusniger N5-5.This work provides an effective method for protein structure research.The structure constructed in this work should be very important to understand the enzyme bioactivities and further developments of fungi tannases.展开更多
The efficiency of organic semiconductor photocatalysts is typically limited by their capability of photogenerated electron transport.Herein,a photocatalyst is proposed initially through the specific axial coordination...The efficiency of organic semiconductor photocatalysts is typically limited by their capability of photogenerated electron transport.Herein,a photocatalyst is proposed initially through the specific axial coordination interaction between imidazole-C_(60)(ImC_(60))and zinc tetraphenyl porphyrin(ZnTPP)named ImC_(60)-ZnTPP.Subsequently,detailed structural characterizations along with theoretical calculation reveal that the unique ImC_(60)-ZnTPP possesses head-to-tail stacking supra-structures,leading to the formation of a continuous array of C_(60)–C_(60) with ultrashort spacing and ensuring strongπ–πinteractions and homogeneous electronic coupling,which could tremendously promote electron transport along the(−111)crystal facet of ImC_(60)-ZnTPP.Consequently,compared to other fullerene-based photocatalysts,ImC_(60)-ZnTPP shows exceptional photocatalytic hydrogen production activity,with an efficiency of up to 80.95 mmol g^(-1) h^(-1).This study provides a novel strategy to design highly efficient fullerene-based photocatalytic systems for solar-driven energy conversion and extend their artificial photosynthetic use.展开更多
Three M_(W)>7.0 earthquakes in 2020-2021 occurred in the Shumagin seismic gap and its adjacent area of the Alaska-Aleutian subduction zone,including the Mw7.8 Simeonof thrust earthquake on July 22,2020,the M_(W)7.6...Three M_(W)>7.0 earthquakes in 2020-2021 occurred in the Shumagin seismic gap and its adjacent area of the Alaska-Aleutian subduction zone,including the Mw7.8 Simeonof thrust earthquake on July 22,2020,the M_(W)7.6 Sand Point strike-slip earthquake on October 19,2020,and the M_(W)8.2 Chignik thrust earthquake on July 29,2021.The spatial and temporal proximity of these three earthquakes prompts us to probe stress-triggering effects among them.Here we examine the coseismic Coulomb stress change imparted by the three earthquakes and their influence on the subduction interface.Our results show that:(1)The Simeonof earthquake has strong loading effects on the subsequent Sand Point and Chignik earthquakes,with the Coulomb stress changes of 3.95 bars and 2.89 bars,respectively.The Coulomb stress change caused by the Sand Point earthquake at the hypocenter of the Chignik earthquake is merely around 0.01 bars,suggesting the negligible triggering effect on the latter earthquake;(2)The triggering effects of the Simeonof,Sand Point,and Chignik earthquakes on aftershocks within three months are not well pronounced because of the triggering rates of 38%,14%,and 43%respectively.Other factors may have played an important role in promoting the occurrence of these aftershocks,such as the roughness of the subduction interface,the complicated velocity structure of the lithosphere,and the heterogeneous prestress therein;(3)The three earthquakes caused remarkable coseismic Coulomb stress changes at the subduction interface nearby these mainshocks,with an average Coulomb stress change of 3.2 bars in the shallow region directly inwards the trench.展开更多
[Object]To providing new data for phylogenesis of Bangia atropurpurea by the sequencing of internal transcribed spacer（ITS region）of rDNA.[Method]B.atropurpurea was collected from Niangziguan Spring in Shanxi,the DN...[Object]To providing new data for phylogenesis of Bangia atropurpurea by the sequencing of internal transcribed spacer（ITS region）of rDNA.[Method]B.atropurpurea was collected from Niangziguan Spring in Shanxi,the DNA was extracted and the primers were designed for PCR amplification so as to obtain ITS gene sequence.[Result]The homology of ITS region between B.atropurpurea and Porphyra oligospermatangia was 75%,which was 79% between B.atropurpurea and P.yezoensis.[Conclusion]Compared with other genes,the ITS sequence had a greater evolution rate.The differences in classification and distribution resulted in the sequence diversity.展开更多
Based on the case history study of sequence stratigraphic framework,sequence model,and the controlling factors on sequence formation in the southern Junggar foreland basin,a contrasting comparison of the characteristi...Based on the case history study of sequence stratigraphic framework,sequence model,and the controlling factors on sequence formation in the southern Junggar foreland basin,a contrasting comparison of the characteristics among the foreland basin,the faulted basin,and the sag basin is made in the aspects of sequence architecture,filling style,the controlling factors on sequence development,the migrations of basin center and depocenter,etc..The current study results show that there are major differences and these are documented as follows.（1） The accommodation space in foreland basin is mainly created by the subsidence caused by thrusting and napping in the foothill belt,resulting in progradational-dominated parasequence sets in the foothill area and retrogradational parasequence sets in the ramp region.（2） The accommodation space in an open-lake system in faulted basin is mainly created by the activities of the basin margin faults;thus,tectonic sequences are formed.However,in the closed-lake system,the subaqueous accommodation is mainly controlled by climatic-influenced lake-level fluctuations,and climatic sequence is formed.（3） In sag basin,a closed-lake system is easily formed due to its generation often within the cratons and isolation from the sea,and its accommodation space creation is mainly controlled by climatic lake-level fluctuations;thus,the sequence architecture in sag basin is similar to that formed on the passive continental margin.展开更多
The study on outcrop sequence stratigraphy of the Sinian section in the Yangtze Gorges an important step in the comprehensive stratigraphy for the Sinian stratotype. In this paper, the base of the Nantuo tillite is se...The study on outcrop sequence stratigraphy of the Sinian section in the Yangtze Gorges an important step in the comprehensive stratigraphy for the Sinian stratotype. In this paper, the base of the Nantuo tillite is selected as the bottom boundary of the Sinian, and the top of the Baimatuo Member of the Dengying Formation is taken as the top boundary. The Sinian lasted from 740 the to 570 Ma. According to the features of sequence boundary facies and the parasequence sets, two supersequences are recognized in the Sinian with six sequences. In this paper, the authors discuss the correlation of those sequences. On the basis of the subsidence rate and the thickness of decompressed deposits, the authors discuss the mechanism of tectonic and sedimentation of the Dengying Formation and the features of high-frequency rhythms as well as the 3rd-order sequences in the Yangtze Gorges.展开更多
On the basis of the records of strong seismic events taking place in soft carbonate sediments, a new seismic sequence system of vibrational liquefaction is established, which consists of a series of units, such as esc...On the basis of the records of strong seismic events taking place in soft carbonate sediments, a new seismic sequence system of vibrational liquefaction is established, which consists of a series of units, such as escaped structure of micrite veins and liquefied deformation formed in the period of seismic liquefaction, land subsidence structure after liquefaction, tsunamic hummocky and turbidite produced by seismic events, This sequence is a generalization and summation of field observation in vast areas, which shows the whole process of a strong seismic event and provides an unified theoretical explanation. The pattern of the seismic sequence by vibrational liquefaction provides one of correlation standards for geologists in the field to discriminate events in carbonate sequences. Based on the pattern of seismic sequence, the authors first advance a new conception of the Palaeo-Tanlu (Tancheng-Lujiang) Zone and discuss primarily its geological significations.展开更多
Using the double-difference relocation algo- rithm, we relocated the 20 April 2013 Lushan, Sichuan, earthquake （Ms 7.0）, and its 4,567 aftershocks recorded during the period between 20 April and May 3, 2013. Our res...Using the double-difference relocation algo- rithm, we relocated the 20 April 2013 Lushan, Sichuan, earthquake （Ms 7.0）, and its 4,567 aftershocks recorded during the period between 20 April and May 3, 2013. Our results showed that most aftershocks are relocated between 10 and 20 km depths, but some large aftershocks were relocated around 30 krn depth and small events extended upward near the surface. Vertical cross sections illustrate a shovel-shaped fault plane with a variable dip angle from the southwest to northeast along the fault. Furthermore, the dip angle of the fault plane is smaller around the mainshock than that in the surrounding areas along the fault. These results suggest that it may be easy to generate the strong earthquake in the place having a small dip angle of the fault, which is somewhat similar to the genesis of the 2008 Wenchuan earthquake. The Lushan mainshock is underlain by the seismically anomalous layers with low-Vp, low-Vs, and high-Poisson＇s ratio anomalies, possibly suggesting that the fluid-filled fractured rock matrices might signifi- cantly reduce the effective normal stress on the fault plane to bring the brittle failure. The seismic gap between Lushan and Wenchuan aftershocks is suspected to be vulnerable to future seismic risks at greater depths, if any.展开更多
Kizmaz [13] studied the difference sequence spaces ∞（A）, c（A）, and co（A）. Several article dealt with the sets of sequences of m-th order difference of which are bounded, convergent, or convergent to zero. Alta...Kizmaz [13] studied the difference sequence spaces ∞（A）, c（A）, and co（A）. Several article dealt with the sets of sequences of m-th order difference of which are bounded, convergent, or convergent to zero. Altay and Basar [5] and Altay, Basar, and Mursaleen [7] introduced the Euler sequence spaces e0^r, ec^r, and e∞^r, respectively. The main purpose of this article is to introduce the spaces e0^r△^（m））, ec^r△^（m））, and e∞^r△^（m））consisting of all sequences whose mth order differences are in the Euler spaces e0^r, ec^r, and e∞^r, respectively. Moreover, the authors give some topological properties and inclusion relations, and determine the α-, β-, and γ-duals of the spaces e0^r△^（m））, ec^r△^（m））, and e∞^r△^（m））, and the Schauder basis of the spaces e0^r△^（m））, ec^r△^（m））. The last section of the article is devoted to the characterization of some matrix mappings on the sequence space ec^r△^（m））.展开更多
The energy of interaction between complementary nucleotides in promoter sequences of E. coli was calculated and visualized. The graphic method for presentation of energy properties of promoter sequences was elaborated...The energy of interaction between complementary nucleotides in promoter sequences of E. coli was calculated and visualized. The graphic method for presentation of energy properties of promoter sequences was elaborated on. Data obtained indicated that energy distribution through the length of promoter sequence results in picture with minima at –35, –8 and +7 regions corresponding to areas with elevated AT (adenine-thymine) content. The most important difference from the random sequences area is related to –8. Four promoter groups and their energy properties were revealed. The promoters with minimal and maximal energy of interaction between complementary nucleotides have low strengths, the strongest promoters correspond to promoter clusters characterized by intermediate energy values.展开更多
A new mono-nuclear CuII complex [Cu（DPP）（DP）Br]（ClO4）H2O （DPP = 2-（3,5- dimethyl-1H-pyrazol-1-yl）-1,10-phenanthroline, DP = 3,5-dimethyl-1H-pyrazole） has been syn- thesized with 2-（3,5-dimethyl-1H-pyrazol-1...A new mono-nuclear CuII complex [Cu（DPP）（DP）Br]（ClO4）H2O （DPP = 2-（3,5- dimethyl-1H-pyrazol-1-yl）-1,10-phenanthroline, DP = 3,5-dimethyl-1H-pyrazole） has been syn- thesized with 2-（3,5-dimethyl-1H-pyrazol-1-yl）-1,10-phenanthroline and 3,5-dimethyl-1H-pyrazole as ligands, and its crystal structure was determined by X-ray crystallography. The crystal is of monoclinic system, space group P21/c with a = 13.765（2）, b = 17.044（3）, c = 10.9044（16）, β= 97.112（2）°, V = 2538.5（6）3, Z = 4, C22H24BrClCuN6O5, Mr = 631.37, Dc = 1.652 g/cm3, F（000） = 1276 and μ= 2.585 mm-1. In the crystal, DPP functions as a tridentate ligand and CuII ions assume a distorted square pyramidal geometry with Br atom lying on the apex, and at the same time, there is π-π stacking between adjacent complexes, which deals with two 1,10-phenanthroline plane rings. In addition to the π-π stacking, there are C-H···Br non-classic hydrogen bonds between adjacent complexes. The theoretical calculations reveal that the π-π stacking and C-H···Br non-classic hydrogen bond result in a weak anti-ferromagnetic interaction with 2J = -5.34 cm-1 and a weak ferromagnetic 2J = 5.92 cm-1, respectively. The magnetic coupling sign from the π-π stacking could be explained with McConnell I spin-polarization mechanism.展开更多
Unconsolidated sandstone reservoirs are most susceptible to sand production that leads to a dramatic oil production decline.In this study,the poly(4-vinyl pyridine)(P_(4)VP)incorporated with self-aggregating behavior ...Unconsolidated sandstone reservoirs are most susceptible to sand production that leads to a dramatic oil production decline.In this study,the poly(4-vinyl pyridine)(P_(4)VP)incorporated with self-aggregating behavior was proposed for sand migration control.The P_(4)VP could aggregate sand grains spontaneously throughπ-πstacking interactions to withstand the drag forces sufficiently.The influential factors on the self-aggregating behavior of the P_(4)VP were evaluated by adhesion force test.The adsorption as well as desorption behavior of P_(4)VP on sand grains was characterized by scanning electron microscopy and adhesion force test at different pH conditions.The result indicated that the pH altered the forms of surface silanol groups on sand grains,which in turn affected the adsorption process of P_(4)VP.The spontaneous dimerization of P_(4)VP molecules resulting from theπ-πstacking interaction was demonstrated by reduced density gradient analysis,which contributed to the self-aggregating behavior and the thermally reversible characteristic of the P_(4)VP.Dynamic sand stabilization test revealed that the P_(4)VP showed wide pH and temperature ranges of application.The production of sands can be mitigated effectively at 20-130℃ within the pH range of 4-8.展开更多
After sea level rises during the Early Cretaceous, upper parts of the Khami Group sediments （Fahliyan, Gadvan, and Dariyan Formations） deposited over Jurassic sediments. The Lower Cretaceous （Aptian） Dariyan Forma...After sea level rises during the Early Cretaceous, upper parts of the Khami Group sediments （Fahliyan, Gadvan, and Dariyan Formations） deposited over Jurassic sediments. The Lower Cretaceous （Aptian） Dariyan Formation （equivalent to the Shu＇aiba Formation and Hawar Member of the Arabian Plate） carbonates, which have hydrocarbon reservoir potential, form the uppermost portion of the Khami Group that unconformably overlays the Gadvan Formation and was unconformably covered by the Kazhdumi Formation and Burgan sandstones. Detailed paleontological, sedimentological, and well log analysis were performed on seven wells from Qeshm Island and offshore in order to analyze the sequence stratigraphy of this interval and correlate with other studies of the Dariyan Formation in this region. According to this study, the Dariyan Formation contains 14 carbonate lithofacies, which deposited on a ramp system that deepened in both directions （NE-wells 5, 6 and SWIwells 1, 2）. Sequence stratigraphy led to recognition of 5 Aptian third-order sequences toward the Bab Basin （SW-well 1） and 4 Aptian third-order sequences toward Qeshm Island （NE-wells 5 and 6） so these areas show higher gamma on the gamma ray logs and probably have higher source rock potential. Other wells （wells 2-4 and 7） mainly deposited in shallower ramp systems and contain 3 Aptian third-order sequences. On the other hand, rudstone and boundstone lithofacies of studied wells have higher reservoir potential and were deposited during Apt 3 and Apt 4 sequences of the Arabian Plate. The Dariyan Formation in Qeshm Island （well 6） and adjacent well （well 5） was deposited in an intrashelf basin that should be classified as a new intrashelf basin in future Aptian paleogeographic maps. We interpret that salt-related differential subsidence, crustal warping, and reactivation of basement faults of the Arabian Plate boundary were responsible for the creation of the intrashelf basin in the Qeshm area.展开更多
基金Innovation Team Development Program of Ministry of Education of China (No. IRT0763)National Natural Science Foundation of China (No. 50205028).
文摘A new optimization method for the optimization of stacking of composite glass fiber laminates is developed. The fiber orientation and angle of the layers of the cylindrical shells are sought considering the buckling load. The proposed optimization algorithm applies both finite element analysis and the mode-pursuing sampling （MPS）method. The algorithms suggest the optimal stacking sequence for achieving the maximal buckling load. The procedure is implemented by integrating ANSYS and MATLAB. The stacking sequence designing for the symmetric angle-ply three-layered and five-layered composite cylinder shells is presented to illustrate the optimization process, respectively. Compared with the genetic algorithms, the proposed optimization method is much faster and efficient for composite staking sequence plan.
基金Funded by the National Natural Science Foundation of China(No.51275393)the Fundamental Research Funds for the Central Universities(No.xjj2017160)
文摘A method to improve the low-velocity impact performance of composite laminate is proposed, and a multi-island genetic algorithm is used for the optimization of composite laminate stacking sequence under low-velocity impact loads based on a 2D dynamic impact finite element analysis. Low-velocity impact tests and compression-after impact（CAI） tests have been conducted to verify the effectiveness of optimization method. Experimental results show that the impact damage areas of the optimized laminate have been reduced by 42.1% compared to the baseline specimen, and the residual compression strength has been increased by 10.79%, from baseline specimen 156.97 MPa to optimized 173.91 MPa. The tests result shows that optimization method can effectively enhance the impact performances of the laminate.
文摘Wind and solar energy are two popular forms of renewable energy used in microgrids and facilitating the transition towards net-zero carbon emissions by 2050.However,they are exceedingly unpredictable since they rely highly on weather and atmospheric conditions.In microgrids,smart energy management systems,such as integrated demand response programs,are permanently established on a step-ahead basis,which means that accu-rate forecasting of wind speed and solar irradiance intervals is becoming increasingly crucial to the optimal operation and planning of microgrids.With this in mind,a novel“bidirectional long short-term memory network”(Bi-LSTM)-based,deep stacked,sequence-to-sequence autoencoder(S2SAE)forecasting model for predicting short-term solar irradiation and wind speed was developed and evaluated in MATLAB.To create a deep stacked S2SAE prediction model,a deep Bi-LSTM-based encoder and decoder are stacked on top of one another to reduce the dimension of the input sequence,extract its features,and then reconstruct it to produce the forecasts.Hyperparameters of the proposed deep stacked S2SAE forecasting model were optimized using the Bayesian optimization algorithm.Moreover,the forecasting performance of the proposed Bi-LSTM-based deep stacked S2SAE model was compared to three other deep,and shallow stacked S2SAEs,i.e.,the LSTM-based deep stacked S2SAE model,gated recurrent unit-based deep stacked S2SAE model,and Bi-LSTM-based shallow stacked S2SAE model.All these models were also optimized and modeled in MATLAB.The results simulated based on actual data confirmed that the proposed model outperformed the alternatives by achieving an accuracy of up to 99.7%,which evidenced the high reliability of the proposed forecasting.
基金financially supported by the Open Project of the State Key Laboratory of Disaster Reduction in Civil Engineering (Grant No. SLDRCE17-01)the National Key Research and Development Program of China (Grant No.2017YFC0805402)the National Natural Science Foundation of China (Grant No. 51808387)。
文摘This study tried to explore the ground movement induced by triple stacked tunneling(TST) with different construction sequences. A case study in Tianjin, China was used to investigate the ground movement during the TST(upper tunneling(UT)). For this, a modified Peck formula was proposed to predict the surface settlement induced by TST. Next, three sets of finite element analyses(FEA) were used to compare the effects of construction sequences(i.e. UT, middle tunneling(MT), and lower tunneling(LT)) on vertical and lateral ground displacements. The results of Tianjin case and UT reveal that compared to a Gaussian distribution for a single tunnel, the surface settlement curve of triple stacked tunnels is a bimodal distribution. It seems that the proposed modified Peck formula can effectively predict the surface settlement induced by TST. The results of the three sets of FEA demonstrate that the construction sequence has a significant influence on the ground movement. Among the three construction sequences, the largest lateral displacement is observed in the MT and the smallest one in UT.The existing tunnel has an inhibitory effect on the vertical displacement. The maximum value of the lateral displacement occurs at the depth of the new tunnel in each construction sequence.
基金financial supports from the Natural Science Foundation of Shandong Province(ZR2021ME037)the National Natural Science Foundation of China(52472259,22179051 and 61604143)+2 种基金the National Key Research and Development Program of China(2021YFE0111000)the Special Fund of Taishan Scholar Program of Shandong Province(tsqnz20221141)the Foundation of Key Laboratory of Advanced Technique&Preparation for Renewable Energy Materials,Ministry of Education,Yunnan Normal University(OF2022-02)。
文摘A comprehensive understanding of the relevance between molecular structure and passivation ability to screen efficient modifiers is essential for enhancing the performance of perovskite solar cells(PSCs).Here,three similarπ-πstacking molecules namely benzophenone(BPN),diphenyl sulfone(DPS),and diphenyl sulfoxide(DPSO)are used as back-interface modifiers in carbon-based CsPbBr_(3)PSCs.After investigation,the results demonstrate the positive effect of the p-πconjugation characteristic inπ-πstacking molecules on maximizing their passivation ability.The p-πco njugation of DPSO enables a higher coordinative activity of oxygen atom in its S=O group than that in 0=S=O group of DPS and C=O group of BPN,which gives a superior passivation effect of DPSO on defects of perovskite films.The modification of DPSO also significantly improves the p-type behavior of perovskite films and the back-interfacial energetics matching,inducing an increase of hole extraction and a decrease of energy loss.Finally,the unencapsulated carbon-based CsPbBr_(3)PSCs with DPSO achieve a maximum power conversion efficiency of 10.60%and outstanding long-term stability in high-temperature,high-humidity(85℃,85%relative humidity)air environment.This work provides insights into the influence of the structure ofπ-πstacking molecules on their ability to improve the perovskite films quality and therefore the PSCs performance.
基金the National Natural Science Foundation of China (No. 21374117)the 100 Talents Program of Chinese Academy of Sciences for financial support
文摘Tannases produced by filamentous fungi are in a family of important hydrolases of gallotannins and have broad industry applications.But until now,the 3-D structures of fungi tannases have not been reported.The protein sequence deduced from the cDNA sequence obtained using RT-PCR amplification was identified as tannase through sequence alignment and phylogenetic analysis.Structure models based on the tannase sequence were collected using I-TASSER,and the model with the best match to the surface charge density-pH titration profile was selected as the final structure for tannase from Aspergillusniger N5-5.This work provides an effective method for protein structure research.The structure constructed in this work should be very important to understand the enzyme bioactivities and further developments of fungi tannases.
基金supported by the National Natural Science Foundation of China(52322204,52072374,52272052)the National Key R&D Program of China(Grant No.2022YFA1205900)the Youth Innovation Promotion Association of CAS(Y2022015).
文摘The efficiency of organic semiconductor photocatalysts is typically limited by their capability of photogenerated electron transport.Herein,a photocatalyst is proposed initially through the specific axial coordination interaction between imidazole-C_(60)(ImC_(60))and zinc tetraphenyl porphyrin(ZnTPP)named ImC_(60)-ZnTPP.Subsequently,detailed structural characterizations along with theoretical calculation reveal that the unique ImC_(60)-ZnTPP possesses head-to-tail stacking supra-structures,leading to the formation of a continuous array of C_(60)–C_(60) with ultrashort spacing and ensuring strongπ–πinteractions and homogeneous electronic coupling,which could tremendously promote electron transport along the(−111)crystal facet of ImC_(60)-ZnTPP.Consequently,compared to other fullerene-based photocatalysts,ImC_(60)-ZnTPP shows exceptional photocatalytic hydrogen production activity,with an efficiency of up to 80.95 mmol g^(-1) h^(-1).This study provides a novel strategy to design highly efficient fullerene-based photocatalytic systems for solar-driven energy conversion and extend their artificial photosynthetic use.
基金supported by grants from the National Natural Science Foundation of China(Grant No.sU2139205,41774011,41874011)the National Key Research and Development Program of China(Grant No.2018YFC1503605)。
文摘Three M_(W)>7.0 earthquakes in 2020-2021 occurred in the Shumagin seismic gap and its adjacent area of the Alaska-Aleutian subduction zone,including the Mw7.8 Simeonof thrust earthquake on July 22,2020,the M_(W)7.6 Sand Point strike-slip earthquake on October 19,2020,and the M_(W)8.2 Chignik thrust earthquake on July 29,2021.The spatial and temporal proximity of these three earthquakes prompts us to probe stress-triggering effects among them.Here we examine the coseismic Coulomb stress change imparted by the three earthquakes and their influence on the subduction interface.Our results show that:(1)The Simeonof earthquake has strong loading effects on the subsequent Sand Point and Chignik earthquakes,with the Coulomb stress changes of 3.95 bars and 2.89 bars,respectively.The Coulomb stress change caused by the Sand Point earthquake at the hypocenter of the Chignik earthquake is merely around 0.01 bars,suggesting the negligible triggering effect on the latter earthquake;(2)The triggering effects of the Simeonof,Sand Point,and Chignik earthquakes on aftershocks within three months are not well pronounced because of the triggering rates of 38%,14%,and 43%respectively.Other factors may have played an important role in promoting the occurrence of these aftershocks,such as the roughness of the subduction interface,the complicated velocity structure of the lithosphere,and the heterogeneous prestress therein;(3)The three earthquakes caused remarkable coseismic Coulomb stress changes at the subduction interface nearby these mainshocks,with an average Coulomb stress change of 3.2 bars in the shallow region directly inwards the trench.
基金Supported by National Science Foundation of China(30970187)~~
文摘[Object]To providing new data for phylogenesis of Bangia atropurpurea by the sequencing of internal transcribed spacer（ITS region）of rDNA.[Method]B.atropurpurea was collected from Niangziguan Spring in Shanxi,the DNA was extracted and the primers were designed for PCR amplification so as to obtain ITS gene sequence.[Result]The homology of ITS region between B.atropurpurea and Porphyra oligospermatangia was 75%,which was 79% between B.atropurpurea and P.yezoensis.[Conclusion]Compared with other genes,the ITS sequence had a greater evolution rate.The differences in classification and distribution resulted in the sequence diversity.
基金supported by the National Science and Technology Major Project (Nos. 2011ZX05003-002 and 2011ZX05009-003-01)the National Basic Research Program of China (No. 2006CB202302)
文摘Based on the case history study of sequence stratigraphic framework,sequence model,and the controlling factors on sequence formation in the southern Junggar foreland basin,a contrasting comparison of the characteristics among the foreland basin,the faulted basin,and the sag basin is made in the aspects of sequence architecture,filling style,the controlling factors on sequence development,the migrations of basin center and depocenter,etc..The current study results show that there are major differences and these are documented as follows.（1） The accommodation space in foreland basin is mainly created by the subsidence caused by thrusting and napping in the foothill belt,resulting in progradational-dominated parasequence sets in the foothill area and retrogradational parasequence sets in the ramp region.（2） The accommodation space in an open-lake system in faulted basin is mainly created by the activities of the basin margin faults;thus,tectonic sequences are formed.However,in the closed-lake system,the subaqueous accommodation is mainly controlled by climatic-influenced lake-level fluctuations,and climatic sequence is formed.（3） In sag basin,a closed-lake system is easily formed due to its generation often within the cratons and isolation from the sea,and its accommodation space creation is mainly controlled by climatic lake-level fluctuations;thus,the sequence architecture in sag basin is similar to that formed on the passive continental margin.
文摘The study on outcrop sequence stratigraphy of the Sinian section in the Yangtze Gorges an important step in the comprehensive stratigraphy for the Sinian stratotype. In this paper, the base of the Nantuo tillite is selected as the bottom boundary of the Sinian, and the top of the Baimatuo Member of the Dengying Formation is taken as the top boundary. The Sinian lasted from 740 the to 570 Ma. According to the features of sequence boundary facies and the parasequence sets, two supersequences are recognized in the Sinian with six sequences. In this paper, the authors discuss the correlation of those sequences. On the basis of the subsidence rate and the thickness of decompressed deposits, the authors discuss the mechanism of tectonic and sedimentation of the Dengying Formation and the features of high-frequency rhythms as well as the 3rd-order sequences in the Yangtze Gorges.
基金A part of the results of the Project cosponsored by the Natural Scienee Fundation of China(49070127)the Chinese Academy of Geological Sciences(B8901)
文摘On the basis of the records of strong seismic events taking place in soft carbonate sediments, a new seismic sequence system of vibrational liquefaction is established, which consists of a series of units, such as escaped structure of micrite veins and liquefied deformation formed in the period of seismic liquefaction, land subsidence structure after liquefaction, tsunamic hummocky and turbidite produced by seismic events, This sequence is a generalization and summation of field observation in vast areas, which shows the whole process of a strong seismic event and provides an unified theoretical explanation. The pattern of the seismic sequence by vibrational liquefaction provides one of correlation standards for geologists in the field to discriminate events in carbonate sequences. Based on the pattern of seismic sequence, the authors first advance a new conception of the Palaeo-Tanlu (Tancheng-Lujiang) Zone and discuss primarily its geological significations.
基金supported by the National Natural Scientific Foundation of China (41274059 and 40974021)Beijing Natural Scientific Foundation (8122039 and 8092028) to J. LeiSpecial Project for Basic Scientific Research (ZDJ2013-12) to G. Zhang
文摘Using the double-difference relocation algo- rithm, we relocated the 20 April 2013 Lushan, Sichuan, earthquake （Ms 7.0）, and its 4,567 aftershocks recorded during the period between 20 April and May 3, 2013. Our results showed that most aftershocks are relocated between 10 and 20 km depths, but some large aftershocks were relocated around 30 krn depth and small events extended upward near the surface. Vertical cross sections illustrate a shovel-shaped fault plane with a variable dip angle from the southwest to northeast along the fault. Furthermore, the dip angle of the fault plane is smaller around the mainshock than that in the surrounding areas along the fault. These results suggest that it may be easy to generate the strong earthquake in the place having a small dip angle of the fault, which is somewhat similar to the genesis of the 2008 Wenchuan earthquake. The Lushan mainshock is underlain by the seismically anomalous layers with low-Vp, low-Vs, and high-Poisson＇s ratio anomalies, possibly suggesting that the fluid-filled fractured rock matrices might signifi- cantly reduce the effective normal stress on the fault plane to bring the brittle failure. The seismic gap between Lushan and Wenchuan aftershocks is suspected to be vulnerable to future seismic risks at greater depths, if any.
文摘Kizmaz [13] studied the difference sequence spaces ∞（A）, c（A）, and co（A）. Several article dealt with the sets of sequences of m-th order difference of which are bounded, convergent, or convergent to zero. Altay and Basar [5] and Altay, Basar, and Mursaleen [7] introduced the Euler sequence spaces e0^r, ec^r, and e∞^r, respectively. The main purpose of this article is to introduce the spaces e0^r△^（m））, ec^r△^（m））, and e∞^r△^（m））consisting of all sequences whose mth order differences are in the Euler spaces e0^r, ec^r, and e∞^r, respectively. Moreover, the authors give some topological properties and inclusion relations, and determine the α-, β-, and γ-duals of the spaces e0^r△^（m））, ec^r△^（m））, and e∞^r△^（m））, and the Schauder basis of the spaces e0^r△^（m））, ec^r△^（m））. The last section of the article is devoted to the characterization of some matrix mappings on the sequence space ec^r△^（m））.
文摘The energy of interaction between complementary nucleotides in promoter sequences of E. coli was calculated and visualized. The graphic method for presentation of energy properties of promoter sequences was elaborated on. Data obtained indicated that energy distribution through the length of promoter sequence results in picture with minima at –35, –8 and +7 regions corresponding to areas with elevated AT (adenine-thymine) content. The most important difference from the random sequences area is related to –8. Four promoter groups and their energy properties were revealed. The promoters with minimal and maximal energy of interaction between complementary nucleotides have low strengths, the strongest promoters correspond to promoter clusters characterized by intermediate energy values.
基金supported by the National Natural Science Foundation of China (No. 20971080)the Natural Science Foundation of Shandong Province (No. ZR2009BM026 and ZR2009BL002)
文摘A new mono-nuclear CuII complex [Cu（DPP）（DP）Br]（ClO4）H2O （DPP = 2-（3,5- dimethyl-1H-pyrazol-1-yl）-1,10-phenanthroline, DP = 3,5-dimethyl-1H-pyrazole） has been syn- thesized with 2-（3,5-dimethyl-1H-pyrazol-1-yl）-1,10-phenanthroline and 3,5-dimethyl-1H-pyrazole as ligands, and its crystal structure was determined by X-ray crystallography. The crystal is of monoclinic system, space group P21/c with a = 13.765（2）, b = 17.044（3）, c = 10.9044（16）, β= 97.112（2）°, V = 2538.5（6）3, Z = 4, C22H24BrClCuN6O5, Mr = 631.37, Dc = 1.652 g/cm3, F（000） = 1276 and μ= 2.585 mm-1. In the crystal, DPP functions as a tridentate ligand and CuII ions assume a distorted square pyramidal geometry with Br atom lying on the apex, and at the same time, there is π-π stacking between adjacent complexes, which deals with two 1,10-phenanthroline plane rings. In addition to the π-π stacking, there are C-H···Br non-classic hydrogen bonds between adjacent complexes. The theoretical calculations reveal that the π-π stacking and C-H···Br non-classic hydrogen bond result in a weak anti-ferromagnetic interaction with 2J = -5.34 cm-1 and a weak ferromagnetic 2J = 5.92 cm-1, respectively. The magnetic coupling sign from the π-π stacking could be explained with McConnell I spin-polarization mechanism.
基金support from the National Key R&D Program of China(grant number 2018YFA0702400)the Major Scientific and Technological Projects of CNPC(grant number ZD2019-183-007)the China Postdoctoral Science Foundation(grant number 2021M702041)。
文摘Unconsolidated sandstone reservoirs are most susceptible to sand production that leads to a dramatic oil production decline.In this study,the poly(4-vinyl pyridine)(P_(4)VP)incorporated with self-aggregating behavior was proposed for sand migration control.The P_(4)VP could aggregate sand grains spontaneously throughπ-πstacking interactions to withstand the drag forces sufficiently.The influential factors on the self-aggregating behavior of the P_(4)VP were evaluated by adhesion force test.The adsorption as well as desorption behavior of P_(4)VP on sand grains was characterized by scanning electron microscopy and adhesion force test at different pH conditions.The result indicated that the pH altered the forms of surface silanol groups on sand grains,which in turn affected the adsorption process of P_(4)VP.The spontaneous dimerization of P_(4)VP molecules resulting from theπ-πstacking interaction was demonstrated by reduced density gradient analysis,which contributed to the self-aggregating behavior and the thermally reversible characteristic of the P_(4)VP.Dynamic sand stabilization test revealed that the P_(4)VP showed wide pH and temperature ranges of application.The production of sands can be mitigated effectively at 20-130℃ within the pH range of 4-8.
基金the National Iranian Oil Company,Exploration Directorate,for the support of this researchthe Department of Geology at Ferdowsi University of Mashhad for their support
文摘After sea level rises during the Early Cretaceous, upper parts of the Khami Group sediments （Fahliyan, Gadvan, and Dariyan Formations） deposited over Jurassic sediments. The Lower Cretaceous （Aptian） Dariyan Formation （equivalent to the Shu＇aiba Formation and Hawar Member of the Arabian Plate） carbonates, which have hydrocarbon reservoir potential, form the uppermost portion of the Khami Group that unconformably overlays the Gadvan Formation and was unconformably covered by the Kazhdumi Formation and Burgan sandstones. Detailed paleontological, sedimentological, and well log analysis were performed on seven wells from Qeshm Island and offshore in order to analyze the sequence stratigraphy of this interval and correlate with other studies of the Dariyan Formation in this region. According to this study, the Dariyan Formation contains 14 carbonate lithofacies, which deposited on a ramp system that deepened in both directions （NE-wells 5, 6 and SWIwells 1, 2）. Sequence stratigraphy led to recognition of 5 Aptian third-order sequences toward the Bab Basin （SW-well 1） and 4 Aptian third-order sequences toward Qeshm Island （NE-wells 5 and 6） so these areas show higher gamma on the gamma ray logs and probably have higher source rock potential. Other wells （wells 2-4 and 7） mainly deposited in shallower ramp systems and contain 3 Aptian third-order sequences. On the other hand, rudstone and boundstone lithofacies of studied wells have higher reservoir potential and were deposited during Apt 3 and Apt 4 sequences of the Arabian Plate. The Dariyan Formation in Qeshm Island （well 6） and adjacent well （well 5） was deposited in an intrashelf basin that should be classified as a new intrashelf basin in future Aptian paleogeographic maps. We interpret that salt-related differential subsidence, crustal warping, and reactivation of basement faults of the Arabian Plate boundary were responsible for the creation of the intrashelf basin in the Qeshm area.
