Search

In this Letter, we apply a class of general two-level non-Hermitian Hamiltonians whose off-diagonal elements are neither equal nor conjugate of each other to study the dynamical approach to shortcut to adiabaticity which is based on engineering the Hamiltonian and dynamical properties of the system to remove any unwanted probability amplitude or implant the desired probability amplitude. Using the special characteristics that one of eigenvalues of the general two-level non-Hermitian Hamiltonian is real and the other is complex, we can decay (amplify) the population exponentially in the undesired (desired) eigenstate, and maintain the conservation of probability amplitude of the other eigenstate. Applying this approach to general two-level non-Hermitian systems, we find that the efficient population transfer can be achieved by our method, which works even in almost instantaneous manner and has a less cost compared with the common approach of shortcut to adiabaticity.

Information diffusion in complex networks has become quite an active research topic. As an important part of this field, intervention against information diffusion processes is attracting ever-increasing attention from network and control engineers. In particular, it is urgent to design intervention schemes for the coevolutionary dynamics between information diffusion processes and coupled networks. For this purpose, we comprehensively study the problem of information diffusion intervention over static and temporal coupling networks. First, individual interactions are described by a modified activity-driven network (ADN) model. Then, we establish a novel node-based susceptible-infected-recovered-susceptible (SIRS) model to characterize the information diffusion dynamics. On these bases, three synergetic intervention strategies are formulated. Second, we derive the critical threshold of the controlled-SIRS system via stability analysis. Accordingly, we exploit a spectral optimization scheme to minimize the outbreak risk or the required budget. Third, we develop an optimal control scheme of dynamically allocating resources to minimize both system loss and intervention expense, in which the optimal intervention inputs are obtained through optimal control theory and a forward-backward sweep algorithm. Finally, extensive simulation results validate the accuracy of theoretical derivation and the performance of our proposed intervention schemes.

The artillery weapon system is a complex system of great non-linearity. There are many factors and their coupling relationship affecting the firing performance of artillery, and the key factor positioning is difficult. How to improve the firing performance of artillery through optimization is a challenge. The current optimization method considers less coupling factors. To approach this challenge, a projectile-artillery-propellant coupled optimization design method is proposed, where a multidisciplinary coupling of projectiles, artillery and propellant is proposed and used to construct an optimization model, and the minimum initial disturbance is taken as the optimization objective. The simulation results show that at the moment when the projectile exist the muzzle, the optimized muzzle vibration displacement is reduced by 47.6%, the muzzle vibration speed is reduced by 33.4%, the average nutation angle is reduced by 63%, the average nutation angular speed is reduced by 27%.

Spectral line widths produced by collisions between charged particles and emitters are of special interest for precise plasma spectroscopy. The highly charged Ar XV ion is demonstrated to have strong intrashell electron interactions, which manifest as an atomic system with many resonance structures, due to the quasi-degeneracy of orbital energies. In this paper we use the relativistic R-matrix method to investigate the electron-impact broadening of highly charged Ar XV ion spectral lines under the impact approximation. It is found that the results considering resonance structures are significantly different from those of the distorted wave approach. Furthermore, we propose a new empirical formula with a correction term to take into account the effect of resonances for electron-impact widths over a relatively wide range of plasma conditions. The corresponding fitting parameters of the new empirical formula for all 47 calculated transitions are also given with an estimated accuracy within 1%, which should be convenient for practical applications. The dataset that supported the findings of this study is available in Science Data Bank, with the link https://doi.org/10.57760/sciencedb.j00113.00101.

In order to build a new power system and achieve the goal of carbon peak and carbon neutralization, intelligent power grid and large-scale intermittent new energy has developed rapidly, as a consequence, the situation of power grid is increasingly complicated. Pumped storage power station, as a key technology of energy storage, which can effectively coordinate the peak-valley contradiction of power grid, is gradually transforming to the direction of intelligence and digitalization. In this context, the development characteristics and difficulties of intelligent pumped storage power stations are explored. Based on BIM and GIS fusion technology, the hierarchical framework of digital twins of pumped storage power station is proposed, the construction of the digital twins of pumped storage power station is elaborated simultaneously. Two application cases of digital twins in pumped storage power stations are introduced combined with operation and maintenance, which provides technical support for intelligent construction of pumped storage power stations with high engineering practical significance.

Journal of physics / G 49(1), 010502 (2022). doi:10.1088/1361-6471/ac2827, Published by IOP Publ., Bristol

Detection and attribution analyses of climate change are crucial in determining whether the observed changes in a climate variable are attributable to human influence. A commonly used method for these analyses is optimal fingerprinting, which regresses observed climate variables on the signals, climate model simulated responses under external forcings. The method scales the simulated response under each external forcing by a scaling factor to best match the observations. The method relies critically on the confidence intervals for the scaling factors. The coverage rate, the relative frequency a confidence interval containing the unknown true value of the corresponding scaling factor, in the prevailing practice has been noted to be lower than desired. The mechanism of this under-coverage and its impacts on detection and attribution analyses, however, have not been investigated. Here we show that the under-coverage is due to insufficient consideration of the uncertainty in estimating the natural variability when fitting the regression and making statistical inferences. The implication is that the ranges of uncertainties in important quantities such as attributable anthropogenic warming and climate sensitivity based on the optimal fingerprinting technique should be wider than what has been believed, especially when the signals are weak. As a remedy, we propose a calibration method to correct this bias in the coverage rate of the confidence levels. Its effectiveness is demonstrated in a simulation study with known ground truth. The use of a large sample of climate model simulations to estimate the natural variability helps to reduce the uncertainty of the scaling factor estimates, and the calibrated confidence intervals provide more valid uncertainty quantification than the uncalibrated. An application to detection and attribution of changes in mean temperature at the global, continental, and subcontinental scale demonstrates that weaker detection and attribution conclusions are obtained with calibrated confidence intervals.

The coexistence of neutron-neutron (n-n), proton-proton (p-p), and neutron-proton (n-p) pairings is investigated by adopting an effective density-dependent contact pairing potential. These three types of pairings can coexist only if the n-p pairing is stronger than the n-n and p-p pairings for the isospin asymmetric nuclear matter. In addition, the existence of n-n and p-p pairs might enhance n-p pairings in asymmetric nuclear matter when the n-p pairing strength is significantly stronger than the n-n and p-p ones. Conversely, the n-p pairing is reduced by the n-n and p-p pairs when the n-p pairing interaction approaches n-n and p-p pairings.

Based on Zhongshan-Tan zhou express 65 # pier boulder geological engineering landscape avenue viaduct, using PLAXIS3D to study in the different boulder embedment depth of squeezed branch piles expansion and common pile ultimate bearing capacity and the applicability of the squeezed branch piles expansion, the calculation results show that the squeezed branch piles expansion of P - S curve is slowly, the ultimate bearing capacity of pile is equal to the load value corresponding to the pile tip diameter when the pile settlement is 1/20, and the ultimate bearing capacity of pile foundation does not always increase(the peak point appears) with the increase of pile length, but the ultimate bearing capacity of ordinary pile is less than the ultimate bearing capacity of extrudated and expanded bracing pile. Under certain geological conditions, the pile length can be shortened and the bearing capacity of pile can be improved effectively. On the basis of the load of the upper bridge which satisfies the geological condition of boulder, the use of extrudated and expanded bracing pile instead of ordinary pile can effectively avoid the boulder, avoid the pile passing through the boulder layer, which can greatly save the construction period and reduce the difficulty of construction.

Taking No.65 pier of Zhongshan-Tanzhou express line as the background, the construction technology of percussive reverse circulation drilling hole forming squeezed branch pile is studied, the construction process of percussive reverse circulation drilling hole forming squeezed branch pile is defined, and through the field trial hole forming test, the points needing attention in field construction are summarized and improved: (1) The top elevation of the steel casing shall not exceed 30cm of the surface elevation, and the hole diameter of the percussion drilling hole shall be slightly larger than the designed hole diameter, so as to avoid the floating of the steel cylinder and the influence of too small hole diameter on the squeezing operation; (2) hole cleaning operation is an important factor for the success or failure of the squeezed branch pile construction, and the sediment thickness has a great influence on the bearing capacity of the pile foundation. After the expansion equipment is squeezed and the reinforcement cage is lowered, the hole cleaning is carried out, and the control points and mud parameters during each hole cleaning are clarified; (3) during the expansion process, the extrusion pressure value and the floating amount of the expansion equipment should be detailed, the geological information should be verified, and the bearing capacity of the pile foundation should be evaluated.

With the rapid development of computer technology, network information technology (hereinafter referred to as NIT) has become an indispensable basic tool in people’s work, which has been applied to all walks of life in our country, including literature education. Language and literature (hereinafter referred to as LAL) are the extension of excellent traditional culture, which is the legacy of the history of all nationalities. Therefore, the study of LAL should not be stagnant, which needs to adapt to the modern technical means. Through the NIT, we can promote the progress of Chinese LAL, which will also have a significant impact on the audience. In the face of the impact of the network, the network culture has been greatly applied, which has a great impact on our traditional literature. With the popularity of Internet catchwords, some people tend to forget their words, which has gradually ignored the art and charm of traditional culture. Therefore, colleges and universities must use NIT to assist LAL research, which will strengthen the understanding of literary works. First of all, this paper analyzes the important role of NIT in LAL teaching. Then, this paper puts forward some problems. Finally, some suggestions are put forward.

The huge flood disaster caused by the barrier lake in a short time usually requires precise emergency decision-making, and the 3D virtual platform of the barrier lake is one of the most important informational support. Traditionally, there are few studies on the reconstruction technology of scale 3D dam lake model based on multi-source perception data. This paper summarizes the types of multi-source perception data used for 3D modeling of barrier lake, and proposes a method for designing and defining 3D data models of barrier lake, a large-scale and a fine local-scale 3D model reconstruction method are studied, building methods are summarized for the main steps of 3D dynamic event simulation, and finally this gives the software architecture design of the barrier lake 3D model platform, Baige barrier lake is taken as an example for practical development and verified the rationality of the method and Feasibility, the software platform provides an important basis for the rescue and disaster relief of the barrier lake in the future.

The intelligent interactive concept as the center, on the basis of the problem of drinking water container, with dressing device of portable items as bottled water way to resolve the problem, through the market similar products from the aspects of capacity, material, carrying way investigation and study, analysis of intelligent interaction design in the application of high-end products embody the characteristics of humanization, intelligent, timeliness, and combine with products created by efficient and convenient. In addition, the feasibility of intelligent interaction in wearable devices with portable items is verified through their intelligence, humanization, timeliness and material requirements. On this basis, through the simulation of functions and forms in wearable devices that can carry items, the intelligentization, humanization and timeliness of the concept of intelligent interaction are analyzed and illustrated with examples.

Aiming at the problems of traditional manual detection of gun firing, such as hidden danger, poor accuracy and low efficiency, this paper proposes an automatic measurement system for the impact point of direct fire shell. Based on the acoustic positioning principle, collimation noise shielding technology based on slit, distributed sensing and coordinate conversion method, the impact is realized by integrating the time difference of shock wave arrival and the geometric relationship between sensors the accurate detection of points can improve the rapid detection ability of artillery performance test and firing training.

In order to accurately determine the stopping state of a vehicle, a wheel location detection method combining enhanced images with CenterNet network was proposed.Image enhancement network was used to process the detected images to improve the contrast and sharpness of images. Then, CenterNet network was used to detect the wheel position in the enhanced image.The algorithm proposed in this paper can efficiently and accurately detect the vehicle wheel location, thus determining a variety of vehicle stopping states, so as to avoid the scene complexity limit, camera Angle and other factors that lead to the wrong judgment of stopping states, and greatly improve the efficiency of roadside parking management.

In this paper, the polyphenols existed in olive leaf were evaluated for its antibacterial activities against Klebsiella pneumoniae. 11 phenols all presented certain antibacterial effect against above-mentioned bacteria, and hydroxytyrosol (HT), oleuropein, 3,4-dihydroxybenzoic acid and caffeic acid, could have excellent inhibition results. The results indicated that several phenols could be a valuable source of natural agents with functional properties for the food and pharmacology industries.

Person re-identification (Re-ID) aims at matching images of the same pedestrian under different cameras. State-of-the-art unsupervised domain adaptation (UDA) methods for person Re-ID transferred the learned knowledge from the source domain and further finetuned with pseudo-label target domain via clustering. To reduce the influence of noisy pseudo labels, the Mutual Mean-Teaching (MMT) framework was proposed by conducting pseudo label refinery to better model inter-sample relations in the target domain. Currently, MMT requires the use of the two same deep models for cooperative correction of noisy labels. In this paper, we extend the MMT framework to use two heterogeneous models for cooperative error correction. Experiments show that the proposed heterogeneous MMT framework can work well with two different deep models and its performance, however, is largely limited by the weaker model.

The marginal block Zana oil field is a typical hard-to-produce carbonate reservoir, thin net pay, poor reservoir physical properties, low pressure, strong heterogeneity, bottom water and gas cap risks coexist, and it is difficult to obtain profitable production in conventional development model. In order to realize its high-efficiency development, research on integrated geological and engineering technology was carried out. First, the static and dynamic data analysis combined with pilot well technology was used to accurately determine the target layer, confirm the material basis and guide the horizontal well orientation optimization; Second, after comprehensive consideration of production, cost, performance feasibility, and management after putting into production, an integrated solution of completion and stimulation was recommended; Third, optimized well trajectory control and cementing quality control, improved the drilling rate of the horizontal section and the cementing quality, created wellbore conditions for subsequent stimulation; Fourth, optimized the stimulation method, the treatment scale and parameters, maximized the stimulated reservoir under the premise of avoiding water and avoiding gas; Fifth, Optimize the formula of acid system and liquid combination system, adopt the gas lift flowing and lift integrated pipe column and assisted technique using coiled tubing and nitrogen, realized rapid backflow in low-pressure wells and reduced the secondary damage of reacted acid. Based on the above research, integrated technology of geological and engineering considered geological, reservoir, completion, and stimulation has been applied 14 wells with a success rate of 100%. The average single well production is 10.7 times that of adjacent wells, the cumulative production exceeded 20 × 104t, achieved significant production and economic benefits, and that all provide a technical reference for the development of similar reservoirs.

We establish an implicit variational principle for the contact Hamiltonian systems generated by the Hamiltonian H(x, u, p) with respect to the contact 1-form under Tonelli and Lipschitz continuity conditions.

Aiming at the problems of low efficiency of path planning, a new node storage structure is introduced and the search method is optimized to improve the deterministic iterative path planning algorithm. First, the number of antibodies is determined based on the connectable starting path point, when generating the initial antibody with the inspiration of the optimal angle vaccine. Then, the connectable path point of the starting point is treated as the root node to rebuild the new path with path filtering by means of the optimal path fit value. The initial optimal antibody is used as the screening criterion to avoid invalid path point mutation with 100% confidence conditions. Finally, a path point is a basic unit that forms the connection network and stores the parameter information that reaches it. After the algorithm iteration, the optimal pathis output. In different maps, the algorithm in this paper is compared with others. The results show that the algorithm effectively reduces the computational cost and has better adaptability to different maps.

The waste feather protein was extracted as modifier to modify cotton fabric. The modified process was selected: the mass fraction of the protein modifier was 4% (weight to the fabric), the mass fraction of the cross-linking reagent was 2%, the processing temperature was 70 °C, and the processing time was 60 min. The structure of the cotton fabric modified was analyzed by infrared spectrometer, scanning electron microscope, XRD and thermogravimetric analysis. The dyeing mechanism and properties of natural naphthoquinone dyes on the cotton fabric modified were analyzed. The results showed that the feather protein grafted onto the cotton fabric by the cross-linking agent. The cross-linking reactions occurred mainly in the amorphous area of the fabric. Furthermore, the dyeing properties of natural naphthoquinone dyes were significantly improved by protein cross-linking agent. The K/S value increased from 1.27 to 7.05 and the color fastness to dry and wet rubbing improved by about one grade.

With the rapid development of the global Internet, academic search engines have become indispensable tools for academic research like literature, papers, books, preprints, and abstracts. The total amount of network information is growing rapidly today, and the global paper output doubles every five years. For academic researchers, it is very difficult to find papers that meet the needs in a large number of articles. Additionally, as the quality of journal papers varied, finding high-quality papers and accurately locating them is getting harder and harder. Many researchers find it tiring and inefficient that when looking for research fields, they need to read through a large number of articles in search results, and manually classify them. Through the clustering algorithm and data visualization and other related technologies, the systematic integration and classification of the search papers will help the researchers to accurately locate the required articles, and can greatly reduce the time for searching the documents. Regarding the previously stated problems, this thesis designs and implements an academic search aggregation engine (referred to as “aggregation engine”) based on cloud computing and some clustering algorithms. On the one hand, the aggregation engine distributes the user’s search request to multiple academic search engines, and then collects and summarizes the paper results, thereby uniformly displaying the search results; on the other hand, from the large number of papers obtained from academic search engines, the aggregation engine analyzes their titles, abstracts, and keywords, clusters papers with similar research points, and visualize clustering results to users, so that the result can be macroscopic and intuitive, grasping all the papers and the research points they involve. This paper first introduces the research background of the subject, through the investigation of the existing search engine and the existing aggregate search engine, it analyzes the needs of the researcher and other customers for the paper search; according to the demand analysis, we proposes a system design that distribute the search request to multiple academic search engines and then aggregated results. Finally, we realised the implementation of the aggregate search engine, and verified the effectiveness of the system through tests

In water-injection development, water-sensitive oil deposits are prone to water injection pressure increase and water injection volume decrease, which makes it difficult to complete production and injection allocation. To solve this problem, on the basis of screening traditional anti-expansion unblocking agents, and combined with the performance evaluation of the formula and core experiment, a reasonable improvement scheme was proposed in this paper to develop a new type water-sensitive oil reservoir anti-expansion unblocking agent. The performance evaluation experiment shows that it has an applicable dissolution rate for oil rock samples and can dissolve inorganic salt scale; the anti-expansion rate is up to 90%; the core dynamic evaluation experiment shows that the core permeability can be increased more than double after the injection of the anti-expansion unblocking agent. The new type water-sensitive anti-expansion unblocking agent were used in 7 wells of the site, and all of them have a good effect of water injection pressure decrease and water injection volume increase.

With the actual mean free path for radiation in air and a simplified nuclear device, a one-dimension simulation research on fireball phenomenon in a sea level atmosphere is carried out based on the multi-group radiation hydrodynamic codes (RDMG). It is shown that our theoretical calculations can describe the whole process of the fireball evolution for strong explosions from the early X-ray expansion stage to the shock wave propagation stage. The radius of the shock wave and the brightness of the fireball are in good agreement with the experimental results. The whole thermal radiation power curve of the fireball evolution for strong atmospheric explosion at sea level is plotted for the first time. The impact of radiation opacity of the nuclear device material on the early fireball phenomenon is also studied. It is found that trajectories of the radiation fronts and case shocks change with the opacity of equivalent device material. From our simulations, we find that only the early fireball depends on the details of the nuclear device, and after the formation of main shock, the evolution is determined by the properties of hot air for strong atmospheric explosion.

The inverse distance weighted algorithm (IDW) is one of the most widely used algorithms in geoscience calculation based on its university and simple theory. However, in the practical application based on borehole sampling data, the distance between boreholes is further than the sampling distance along the bedding direction of one borehole, and it needs to search all the near points through a large number of distance calculation, and the process is very slow, so this lacks practicality in the spatial interpolation of the large amount and non-uniform distribution data. Based on the special features of the borehole sampling data, this paper presents a fast adaptive and improved inverse distance weighted interpolation method. And firstly the sample point position could be indexed by the adaptive cube grid raster, then determine the index grid in the horizontal and vertical directions of the interpolation point, and combine these grids for the finally IDW calculation, which significantly improves the search speed of the adjacent interpolation calculation points. It can improve the engineering applicability of the IDW method, especially the three-dimensional spatial interpolation and computing has a good application prospect.

For the problem of high repetition rate of image resources collected by general theme crawler, a theme image crawler system is designed to reduce image similarity. The main contents of the design include the main function modules of the crawler, the workflow of the system and the implementation method of the key modules. The difference hash algorithm is used to solve the problem of image similarity effectively. Combined with Web text cosine correlation algorithm and link PageRank algorithm, the paper comprehensively evaluates the relevance between Web resources and topics. The experimental results show that the subject image crawler can effectively reduce the similarity of the collected images and improve the efficiency of crawler image resources acquisition.

The Aktobe project is at the east margin of the Pre-Caspian Basin, where horizontal well is mainly used to develop the low porosity and permeability layers. To improve production per well, the horizontal interval increased from +/-400m to +1000m. Due to complicated geological structure, variable boundary and thickness of target layers, the RSS was employed to improve the rate in layer. But the average ROP was just 2.36m/hr, and average footage was just 335m per bit due to high strength of the formation. To solve this problem, the wearing characteristic of PDC bits was analyzed. The BHA and table rotary speed were optimized on the basis of drilling pipe vibrating calculation. Thus, the drilling technology for hard and long horizontal interval, including high performance PDC bit, RSS, PDM, BHA with 1/2 stabilizer, has been worked out. The technology was used in 5 wells, of which 4 wells at 60 rpm, had stick-slip index of less than 80%, the drill bits out of the wells had few cutters broken by vibrating; 1 well had stick-slip index of higher than 80% at 70-80rpm, and the drill bits out of the well had many cutters broken by vibrating. Compared with Well H814, the horizontal section drilling time shortened from 22.5d to 9.6d, by 57.7%, ROP increased by 261.4%, and the footage increased by 195.5%. The optimized horizontal drilling technology for hard formation could provide reference for the drilling of similar hard formation, especially for the other oilfields in the Pre-Caspian Basin.

Precise angular displacement estimation provides a route to correct the measurement bases of two parties in quantum teleportation. In this paper, we propose an angular momentum-enhanced estimation protocol deploying tunable squeezed Bell states and parity detection. The Heisenberg-scaling sensitivity and -fold super-resolved oscillating fringes with quantum number l are reachable in our protocol. We analyze the effect of tunable factor on sensitivity, and the advantages originating from spin and orbital angular momenta are also discussed.