Exchange Channels Research Articles

Research and Application of System-based Clustering and Principal Component Analysis Algorithms

The Silk Road was a channel of cultural exchange between China and the West in ancient times, in which glass was a valuable physical evidence of early trade, and the early glass in China was made by absorbing some foreign technology, which also led to a different chemical composition. Nowadays, most of the glass artifacts are roughly divided into lead-barium glass and high-potassium glass, and each of the different parts of the artifacts will be observed and sampled for analysis in the study of the artifacts, and the identification of their composition types has been hampered by natural weathering over thousands of years. Therefore, in view of such problems and the large number and complexity of chemical components, we propose to sub-classify the different types of glass artifacts through systematic clustering and principal component analysis algorithm model, and the basis of classification is the chemical composition, classification of the content of the different artifact sampling points, that is, the artifact number, and finally through sensitivity analysis to evaluate and test the classification results. The classification results can greatly reduce the workload of analyzing and identifying the types of artifacts, and provide a reference basis and methodological guidance for the problem of identifying and classifying artifacts.

“In Parents’ School Experience, the Teacher was just Lecturing at the Front”

Our study examines communication and cooperation between schools that have implemented personalized learning concepts and the families of their students. The study forms part of a longitudinal mixed-methods research project (2012–2015, supported by the foundation Mercator Switzerland). Conducting a qualitative content analysis of interviews and strategic documents (N = 12 schools), we developed an analytic instrument, applying a semi-deductive procedure. It is based on research on school-family partnerships and consists of five communication and cooperation structures (a) channels of two-way information exchange and cooperation; b) information flow from schools to parents; c) parent events; d) parent volunteering; e) parent involvement in decision-making) and five content and object areas i) psychological, pedagogical, and school concepts; ii) understanding families; iii) learning and instruction; iv) learning progress and achievement; v) problems, conflicts). The linkage between the structures and the content of the interactions led to three paradigmatic types of schools. Type 1: Informal communication and cooperation; Type 2: Reactive communication and cooperation; Type 3: Strategic communication and cooperation. The results indicate that it can be particularly advantageous to center the communication on student progress, to focus parent events on education-related topics, and to give the parents a voice in decision-making processes.

Phase separation of the nuclear pore complex facilitates selective nuclear transport to regulate plant defense against pathogen and pest invasion

The nuclear pore complex (NPC), the sole exchange channel between the nucleus and cytoplasm, is composed of several subcomplexes, among which the central barrier determines the permeability/selectivity of the NPC to dominate the nucleocytoplasmic trafficking essential for many important signaling events in yeast and mammals. How plant NPC central barrier controls selective transport is a crucial question remaining to be elucidated. In this study, we uncovered that phase separation of the central barrier is critical for the permeability and selectivity of plant NPC in the regulation of various biotic stresses. Phenotypic assays of nup62 mutants and complementary lines showed that NUP62 positively regulates plant defense against Botrytis cinerea, one of the world’s most disastrous plant pathogens. Furthermore, in vivo imaging and in vitro biochemical evidence revealed that plant NPC central barrier undergoes phase separation to regulate selective nucleocytoplasmic transport of immune regulators, as exemplified by MPK3, essential for plant resistance to B. cinerea. Moreover, genetic analysis demonstrated that NPC phase separation plays an important role in plant defense against fungal and bacterial infection as well as insect attack. These findings reveal that phase separation of the NPC central barrier serves as an important mechanism to mediate nucleocytoplasmic transport of immune regulators and activate plant defense against a broad range of biotic stresses.

Least action description of dynamic pairing correlations in the fission of curium and californium isotopes based on the Gogny energy density functional

The impact of dynamic pairing correlations and their interplay with Coulomb antipairing effects on the systematic of the spontaneous fission half-lives for the nuclei $^{240-250}$Cm and $^{240-250}$Cf is analyzed, using a hierarchy of approximations based on the parametrization D1M of the Gogny energy density functional (EDF). First, the constrained Hartree-Fock-Bogoliubov (HFB) approximation is used to compute deformed mean-field configurations, zero-point quantum corrections and collective inertias either by using the Slater approximation to Coulomb exchange and neglecting Coulomb antipairing or by fully considering the exchange and pairing channels of the Coulomb interaction. Next, the properties of the {\it{least action}} and {\it{least energy}} fission paths are compared. In the {\it{least action}} case, pairing is identified as the relevant degree of freedom in order to minimize the action entering the Wentzel-Kramers-Brillouin (WKB) approximation to the tunneling probability through the fission barrier. Irrespective of the treatment of Coulomb exchange and antipairing, it is shown that the {\it{least action}} path obtained taking into account the pairing degree of freedom leads to stronger pairing correlations that significantly reduce the spontaneous fission half-lives $t_{SF}$ improving thereby the comparison with the experiment by several orders of magnitude. It is also shown that the Coulomb antipairing effect is, to a large extent, washed out by the {\it{least action}} procedure and therefore the $t_{SF}$ values obtained by the two different treatments of the Coulomb exchange and pairing are of similar quality.

Analysis of chemical composition of ancient glass products based on grey correlation method

The Silk Road was the channel of cultural exchange between China and the West in ancient times, and the glass is the precious material evidence of early trade. Early glass was often made into bead-shaped ornaments and introduced into our country in West Asia and Egypt. After absorbing the technology, the ancient glass in our country was made locally. Although the appearance of the glass products was similar to the foreign ones, the chemical composition was different. Therefore, the analysis and identification of chemical composition is an important aspect to identify and study ancient glass products. In view of the different contents of weathering or non-weathering chemical components of different types of glass relics, this paper considers the types, patterns, colors, chemical components and other factors, and ignores environment-related factors, such as atmospheric environment, pH value, burial time, depth and other factors. Based on the existing data and relevant research results of domestic and foreign scholars, the classification rules of chemical components of high-potassium glass and lead-barium glass were obtained by using grey correlation analysis model, Chi-square test and improved weighted average algorithm. It is pointed out that the contents of , , and should be observed in order to analyze and identify ancient glass products.

Monetary Policy Shocks and Output Growth in Nigeria: Which Shocks are more Important

Purpose: Recognizing the importance of effective policymaking requires an understanding of Monetary Policy Shocks and Output Growth in Nigeria. The purpose of the paper is to examine how interest rate and exchange rate channels of the transmission mechanism affect output growth in Nigeria in response to monetary shocks. Methodology: The structural vector autoregression method is the empirical model. In the empirical analysis, quarterly data from 2000 to 2020 were used for the gross domestic product, nominal effective exchange rate, consumer price index, monetary policy rate, and open buyback. Findings: The results of the impulse response function showed that in Nigeria, monetary policy shocks are more significant because they have a long-lasting impact on growth up to the sixteenth quarter of the forecast horizon. Originality/value: The study's conclusions would enable Nigerian policymakers to anticipate consequences of monetary policy shocks through indirect demand-side Keynesian monetary policy transmission mechanism through the channels of exchange and interest rates. The study recommends that to move the economy toward pre-determined directions, monetary authorities should be cautious of the level/quantity of money in circulation rather than focusing on increasing or decreasing the monetary policy rate.

Multi-Agent System for Rogue Drone Interception

A multitude of applications based on unmanned aircraft vehicles (UAVs), in conjunction with the UAVs' diminishing costs and increasing capabilities, present a major threat to public safety as well as critical infrastructure security, leading to the need for versatile and robust counter-drone solutions. This work presents a novel multi-agent jamming system (MUAV-JS), where a group of cooperative autonomous agents employ various algorithms (detection, tracking, jamming, and self-localization) to counter unauthorized drone operations. The proposed system employs a joint wireless jamming and cooperative positioning framework to best track and intercept the moving rogue drone, utilizing a relative positioning system based on signals of opportunity in conjunction with inertial and vision measurements. Software-defined radio technology is incorporated on the pursuer agent to achieve rogue drone GPS disruption, while at the same time the autonomous agents cooperate to compute the location estimate of the pursuer agent. In the presence of jamming, to improve the wireless communication performance of the autonomous agents, a cellular communication architecture is also used as an additional channel for control and information exchange. For evaluation purposes, a prototype multi-agent system is designed, implemented, and tested in a real-world environment to demonstrate its enhanced localization and jamming performance, when compared to single-agent approaches.

An investigation of the significance of the association of each attribute of ancient glass products based on cardinal distribution

The Silk Road was a key channel for trade and cultural exchange between China and the West in ancient times, and one of the gems of the early exchange was glass products. The composition and properties of glass from the East and the West often differ greatly because of the different production processes, but the problem of glass identification has been an ancient challenge. For the analysis of the composition and origin of ancient glass products, this paper is a mathematical approach to model design, avoiding the duplication of labor into this area. This paper uses chi-square test and correspondence analysis to first determine which factors are significantly correlated with glass products, and then further determine the correlation with the factors. The use of box-line plots allows for a very visual analysis of the statistical patterns of the presence or absence of chemical composition content on the surface of artifact samples. For predicting the chemical composition content before weathering, the approximate chemical composition content was first estimated based on the average rate of change of each chemical composition before and after weathering, and then a multiple linear regression model was used to correct for the chemical composition content. It was finally concluded that the weathering of glass surface was significantly correlated with glass type, and high potassium glass was not easily differentiated, while lead-barium glass was easily weathered; the silica content changed most significantly before and after weathering of high potassium glass, with an average change rate of 25.98%, and the silica and lead oxide content changed most significantly before and after weathering of lead-barium glass, with average change rates of 29.75% and 23.77%, respectively.

Thermal Condition in the Channels of Plate Heat Exchangers

Equipping heat points with plate-type heat exchangers is an integral structural element of the 3rd generation heat and power network and a component of the reliability of the heat supply system as a whole. It has been established that the optimization calculations of heat exchangers of this type are difficult due to the absence of dependences on heat transfer and hydraulic resistance between the channels in the structural space of the heat exchanger.Purpose of research. To clarify the method of calculating plate heat exchangers, excluding the equality of thermal and hydraulic conditions from the generally accepted assumptions.Methods. The research methodology is based on the use of the law of conservation of mass in order to determine the temperature parameters of working fluids in each channel. The solution of this problem is proposed in the form of a system of equations, each of the equations of which characterizes the thermal balance of the channel under consideration. A computer model of the heat exchanger is constructed in order to conduct a numerical study of the thermal regime of the heat exchanger.Results. It is indicated that as an assumption in the well-known mathematical model for calculating the thermal regime of a plate-type heat exchanger, the condition of equal distribution of fluid flows between channels is accepted. This restriction leads to equalization of liquid temperatures in each channel. Taking into account the geometric arrangement of the channels, the excess of the final temperature of the heating and heated coolant in the first and last channels with respect to known data is up to 10%. The results of the study confirm the hypothesis of uneven heating of the coolant along the length of the plate package due to the uneven flow distribution between the channels.Conclusion. The results of analytical calculation and modeling in the SolidWorks environment of the temperature regime in the channels of a plate-type heat exchanger indicate a significant influence of the geometric arrangement on the thermal regime in the channels. The formulated provisions of the mathematical description of the unevenness of the thermal regime of heat exchange channels, taking into account the location of the plates, are recommended to be used when improving the design parameters of plate-type heat exchangers.

Graphene and boron nitride foams for smart functional applications

AbstractGraphene and boron nitride (BN) foams, as two types of three‐dimensional (3D) nanomaterials consisting of two‐dimensional (2D) nanosheets, can inherit a series of excellent properties of the 2D individuals. The internal 3D network can prevent aggregation or restacking between isolated graphene or BN nanosheets, and provide a highway for phonon/electron transports. Moreover, the interconnected porous structure creates a continual channel for the mass exchange of exotic species. The light‐element graphene and BN foams can thus possess the characteristics of low density, high porosity, high surface area, and excellent mechanical, thermal, and electrical properties. Benefiting from these advantages, they show a wide range of applications. The usual synthesis methods and the recent functional applications of graphene and BN foams are reviewed herein, including their applications as supporting materials, elastic materials, acoustic shielding materials, thermal interface materials, electromagnetic shielding materials, adsorption materials, electrocatalysis and thermal catalyses materials, electrochemical energy storage, and thermal energy storage materials. Current challenges and outlooks are additionally discussed.

Response mechanism of chloroplast ROS signaling to radon exposure in Tillandsia usneoides as an air pollution sensor

This study analyzed the interaction between CO2 and Rn absorption in Tillandsia usneoides to reveal the influence of aerial plants on radon (Rn) absorption. Chloroplast proteomics and transcriptomics techniques were used to analyze the molecular mechanism of the response of T. usneoides to Rn exposure. The CO2 and Rn absorption were highest under the following conditions: Day 25 °C; Night 15 °C; Light intensity 2500 lux; Light duration 10 h. The CO2 exchange channels were one point of entry for the absorbed Rn. Rn exposure significantly increased the enzyme activities of leaf antioxidant and AsA-GSH cycle pathways. Overall, 370 differentially expressed proteins (114 upregulated; 256 downregulated) were identified in the chloroplast. Rn exposure interfered with the expression levels of critical proteins in the electron transport chain of the photosystems and in the REDOX homeostasis of chloroplasts, leading to 1.78-fold increases in the chloroplast H2O2 content. A total of 3440 differentially regulated genes (up 3255; down 185) were identified using transcriptomic analysis. Upregulation of the intracellular antioxidant enzyme system and the AsA-GSH cycle pathway enhanced the antioxidant capacity of leaves. These responses effectively circumvented the peroxidation damage that would be caused by ROS accumulation induced by Rn exposure.

Relationship between Dietary Polyphenols and Gut Microbiota: New Clues to Improve Cognitive Disorders, Mood Disorders and Circadian Rhythms.

Cognitive, mood and sleep disorders are common and intractable disorders of the central nervous system, causing great inconvenience to the lives of those affected. The gut-brain axis plays a vital role in studying neurological disorders such as neurodegenerative diseases by acting as a channel for a bidirectional information exchange between the gut microbiota and the nervous system. Dietary polyphenols have received widespread attention because of their excellent biological activity and their wide range of sources, structural diversity and low toxicity. Dietary intervention through the increased intake of dietary polyphenols is an emerging strategy for improving circadian rhythms and treating metabolic disorders. Dietary polyphenols have been shown to play an essential role in regulating intestinal flora, mainly by maintaining the balance of the intestinal flora and enhancing host immunity, thereby suppressing neurodegenerative pathologies. This paper reviewed the bidirectional interactions between the gut microbiota and the brain and their effects on the central nervous system, focusing on dietary polyphenols that regulate circadian rhythms and maintain the health of the central nervous system through the gut-brain axis.

Fitting a self-interacting dark matter model to data ranging from satellite galaxies to galaxy clusters

We present a fit to observational data in an asymmetric self-interacting dark matter model using our recently calculated cross sections that incorporate both $t$-channel and $u$-channel exchanges in the scattering of identical particles. We find good fits to the data ranging from dwarf galaxies to galaxy clusters, and equivalent relative velocities from $\sim 20$ km/sec to $\gtrsim 10^3$ km/s. We compare our results with previous fits that used only $t$-channel exchange contributions to the scattering.

Recommendations to Improve the Nature and Extent of Relationships Among Organizations Within a Network to Enhance Supports for Transgender Survivors of Sexual Assault.

To enhance the provision of comprehensive supports to transgender (trans) survivors of sexual assault, a structurally marginalized group with complex care needs, we developed an intersectoral network of trans-positive health care and community organizations in Ontario, Canada. As a baseline evaluation of the network, we conducted a social network analysis to determine the extent and nature of collaboration, communication, and connection among members. Relational data (eg, activities of collaboration) were collected from June to July 2021, and analyzed using a validated survey tool, Program to Analyze, Record, and Track Networks to Enhance Relationships (PARTNER). We shared findings in a virtual consultation session with key stakeholders and facilitated discussion to generate action items. Consultation data were synthesized into 12 themes through conventional content analysis. An intersectoral network in Ontario, Canada. Of the 119 representatives of trans-positive health care and community organizations invited to participate in this study, 78 (65.5%) completed the survey. Proportion/count of organizations collaborating with other organizations. Network scores for value and trust. Almost all (97.5%) invited organizations were listed as collaborators, representing 378 unique relationships. The network achieved a value score of 70.4% and trust score of 83.4%. The most prominent themes were "Communication and knowledge exchange channels," "Clearer roles and contributions," "Indicators of success," and "Client voices at the centre." As key antecedents of network success, high value and trust indicate that network member organizations are well positioned to further foster knowledge sharing, define their roles and contributions, prioritize the integration of trans voices in all activities, and, ultimately, achieve common goals with clearly defined outcomes. There is great potential to optimize network functioning and advance the network's mission to improve services for trans survivors by mobilizing these findings into recommendations.

Experimental investigation on flow boiling characteristics in offset strip fin channels under different sloshing conditions

In order to reveal the effects of sloshing movement on the performance of the plate-fin heat exchangers applied in floating liquefied natural gas platforms and environment control system of aircrafts, the flow boiling characteristics in offset strip fin channels of plate-fin heat exchangers under different sloshing conditions were investigated experimentally, covering rolling, pitching and swaying movements. The results show that, the rotational type movements enhance the transient heat transfer coefficient by a maximum of 21.1% at low vapor quality condition and weaken the transient heat transfer coefficient by a maximum of 27.7% at high vapor quality condition, while the transitional type movements enhance the heat transfer at high vapor quality. Fast Fourier transform method was used in the spectrum analysis of flow instabilities, and there are two peak frequencies caused by the inlet fluctuations, the distribution of the liquid phase and the enhanced turbulence. The time-average factors were proposed to evaluate the average heat transfer performance during the sloshing period. The ranges of sloshing time-average factors for rolling, pitching, and swaying conditions are 0.861 ∼ 1.079, 0.923 ∼ 1.061, 0.834 ∼ 1.064 and 0.994 ∼ 1.090, respectively. As the mass flux and sloshing period increase, the time-average factors trend to 1.0, and increase at the transitional sloshing movement. With the increasing amplitude, the time-average factors increase from 1 to a maximal value of 1.093. The correlations to predict the time-average two-phase heat transfer coefficients under rolling, pitching, swaying, and heaving conditions for offset strip fins have been developed, and the deviations are within ± 10 %.

Certainty in Uncertain Times: Dental Education during the COVID-19 Pandemic–A Qualitative Study

The restrictions concerning social contact due to the COVID-19 pandemic implied a rethinking of teaching methods at universities in general, and for practice-oriented teaching such as dental education in particular. This qualitative study aimed to assess aspects of feelings of certainty and uncertainty during this specific education process, incorporating the perspectives of teaching staff and dental students. Qualitative methods based on interviews were used for data collection. Dental students from different academic years (second, third, fourth, and fifth) and teaching staff responsible for the content and implementation of courses within the dental curriculum were recruited. The data analysis was performed by qualitative content analysis. A total of 39 dental students and 19 teaching staff participated. When students and staff dealt positively with this specific situation, certainty was achieved. The availability of presentations and clear communication enhanced feelings of certainty. The participants often felt unsure about how to handle such a challenging situation and felt insecure when planning for the semester. The students missed contact with other students and argued that the information policy on their dental studies was not transparent enough. In addition, dental students and teaching staff were nervous about the risk of infection from COVID-19, especially in practical courses with patient contact. The COVID-19 pandemic situation leads to a rethinking of dental education. Feelings of certainty can be strengthened by clear and transparent communication as well as training in online teaching methods. To reduce uncertainty, it is crucial to establish channels for information exchange and feedback.

Heat transfer enhancement in a rectangular channel with flow-induced pitching, heaving or surging of an airfoil

This paper presents a numerical investigation of the flow-induced pitching, heaving or surging of an airfoil in a rectangular channel for heat transfer enhancement. The flow dynamics, airfoil fluttering response, and heat transfer performance are analyzed and discussed at four different Reynolds numbers (Re = 700, 1000, 1300 and 1500), three rotational axis locations (ax/C=0.25, 0.33 and 0.42), two airfoil perturbation modes (passive vs. active), and three combinations of multiple airfoil freedoms (pitch only, pitch and heave, and pitch and surge) with various stiffness coefficients. It is found that after Reynolds number reaches 1000, the pitch only airfoil starts the similar self-fluttering pattern, and the fluttering effect becomes the dominant influencer for increasing the Nusselt number compared to the Reynolds number effect. Placing the rotational axis at ax/C=0.42 achieves the highest thermal enhancement factor η of 1.4, while when ax/C=0.25, the airfoil oscillation diminish effect is vast because of its aerodynamic center. The passive pitching airfoil can achieve more than 6% of the thermal enhancement factor than the active ones. Adding another heave or surge degree of freedom to the pitching airfoil, the heat transfer enhancement of the channel can also be improved. The present work can facilitate future optimizations of airfoil-based flow-structure interaction system for heat exchanger channels.

Study on Composition Analysis and Identification of Ancient Glass Products

The Silk Road, as a channel of cultural exchange between China and the West in ancient times, promoted the development and dissemination of glass technology and culture in ancient China. The analysis of the chemical factors of ancient glass is of great help to the study of the economy. The main research content of this paper is to analyze the chemical content of ancient glass products. To analyze the correlation of different types of chemical components, first of all, this paper uses SPSS to carry out grey correlation analysis. According to the grey correlation degree, we can screen out the elements with the greatest degree of correlation between each chemical component and it. Then, the paired samples t-test was used to analyze the differences in chemical composition association between different categories. At the significance level a = 0.05, it was found that except for SO2, there were significant differences in the chemical composition of other elements among different categories.

Meloidogyne graminicola Population Structure in China Suggests a South-to-North Expansion.

The distribution range of root-knot nematode Meloidogyne graminicola is rapidly expanding, posing a severe threat to rice production. In this study, the sequences of cytochrome oxidase subunit I (COI) genes of rice M. graminicola populations from all reported provinces in China were amplified and sequenced by PCR. The distribution pattern and phylogenetic tree showed that all 54 M. graminicola populations in China have distinct geographical distribution characteristics; specifically, cluster 1 (southern China), cluster 2 (central south and southwest China), and cluster 3 (central and eastern China). The high haplotype diversity (Hd = 0.646) and low nucleotide diversity (π = 0.00682), combined with the negative value of Tajima's D (-1.252) and Fu's Fs (-3.06764), suggested that all nematode populations were expanding. The existence of high genetic differentiation (Fst = 0.5933) and low gene flow (Nm = 0.3333) indicated that there was a block of gene exchange between most populations. Mutation accumulation with population expansion might be directly responsible for the high genetic differentiation; therefore, the tested nematode population showed high within-group genetic variation (96.30%). The haplotype Hap8 was located at the bottom of the network topology, with the widest distribution and the highest frequency (59.26%), indicating that it was the ancestral haplotype. The populations in cluster 3 were newly invasive according to the lowest frequency of occurrence of Hap8, the highest number of endemic haplotypes, and the highest total haplotype frequency (60%). In contrast, cluster 1 having the highest genetic diversity (Hd = 0.772, π = 0.01127) indicated that it was the most primitive. Interestingly, the highest gene flow (Nm > 1), lowest genetic differentiation (Fst ≤ 0.33), and closest genetic distance (0.000) only occurred between the Guangdong/Hainan population and others, which suggested that there might be channels for gene exchange between them and that long-distance dispersal occurred. This suggestion is further confirmed by the weak correlation between genetic distance and geographical distance. Based on these data, a hypothesis can be drawn that M. graminicola populations in China were spreading from south to north, specifically from Guangdong and Hainan Provinces to other regions. Natural selection (including anthropogenic) and genetic drift were the main drivers of their evolution. Coincidentally, this hypothesis was consistent with the gradual warming trend and the chronological order of reporting these populations. The main factors influencing current M. graminicola population expansion and distribution patterns might be geography, climate, long-distance seedling transport, interregional operations of agricultural machinery, and rotation mode. It reminds human beings of the necessity to be vigilant about preventing nematode disease according to local conditions all year round.

Halogen Bonding Channels for Magnetic Exchange in Cu(II) Complexes with 2,5-Di(methylthio)-1,3,4-thiadiazole.

Copper(II) complexes with 2,5-bis(methylthio)-1,3,4-thiadiazole (tda) formulated as [Cu(tda)n X2 ] (n=2, X=Cl- , Br- , C2 N3 - ; n= 1, X=C2 N3 - ) have been isolated and fully characterized. The crystal structures of all compounds have been determined using single-crystal X-ray diffraction (SCXRD). A study of the magnetic susceptibility in the range 1.77-300 K has shown that magnetic properties of the [Cu(tda)2 Cl2 ] and [Cu(tda)2 Br2 ] complexes match those of 1D chains of antiferromagnetically-coupled Cu2+ ions. The intrachain interaction J in [Cu(tda)2 Cl2 ] turns out to be ∼1.2 times weaker than in its bromide analogue. In its turn, [Cu(tda)2 (C2 N3 )2 ] exhibits J being an order of magnitude smaller and of the opposite ferromagnetic sign. Halogen bonding (HB) between adjacent complexes is much stronger than the H-bonds or π-π interactions between tda ligands according to the DFT calculations.