“去连接”:互联网平台连接性的再思考——以生成式AI为例

“连接”是互联网运行的基础逻辑,“连接性”是互联网的基本特性。随着互联网进入移动时代,“连接”的规模和形态发生变化,无时无处不在的“连接”正在重新定义虚拟与现实的界限。从发展历史来看,互联网连接性的演进遵循了由复杂到简单的“去连接”原则,为用户提供便利已经成为互联网平台生存和竞争的必要条件。随着ChatGPT、Bing Chat、Notion AI、Opus Clip等生成式AI的出现,“去连接”呈现新一轮的发展。文章主要采用文献分析法,结合生成式AI的案例研究,探讨“去连接”这一概念和现象,并考察在这一背景下互联网用户的思维方式和媒介使用行为的变化。

Cognitive principle and discoursal coherence

Cohesion, the main form of discoursal coherence, has traditionally been analyzed from the perspective of functional linguistics and its study mainly focuses on surface explicit cohesive devices. We hold that it is of much higher explanatory power to study discoursal coherence from the point of view of cognitive linguistics and the construction of discoursal coherence has been restricted by the cognitive principles like iconicity, cognitive metaphor and cognitive metonymy. Based upon the above analysis, the article discusses show such cognitive principles act as cohesive devices and play a role in the formation of discoursal coherence.

Construction of Vectors to Express Foreign Protein within Potato Starch Grains

[Objective] The aim is to study the construction of vectors expressing foreign protein in potato starch grains specifically, and provide some reference for solving industrialized core problem of high cost and low expression level of foreign protein. [Method] By using molecular biological techniques of RT-PCR and nested PCR, plant expression vector for the foreign protein locating in the potato starch grains was constructed. [ Result] Coding sequence （ GC20 ） of potato starch grains that was located and expressed by GBSSI promoter was cloned. Plant expression vector was screened out through connection, transformation and enzyme digestion identification. [ Conclusion] This result laid a foundation for further screening the foreign protein on the potato starch grains.

Construction and Identification of siRNA Expression Vector Targeting Nucleocapsid Protein N gene of PRRSV

[ Objective] The aim of this study was to investigate the construction and identification of siRNA expression vector targeting nucleocapsid protein N gone of PRRSV. [Method] Three siRNA oligonucleotides targeting nucleocapsid protein N gone sequence of PRRSV were designed or synthesized, and then inserted into CMV promoter downstream to clone into pSilencer 4,1 -CMV eukaryotic expression vector. The recombinant expression vector was identified by enzyme digestion and DNA sequencing. [ Result] The results showed that the siRNA interference recombinant plasmid vector pSilencer-N targeting nucleocapsid protein gone expression had been successfully constructed. [ Conclusion] This study lays a foundation for studies on the controlling PRRSV by RNA interference technique .

SPECIFIC INHIBITION OF CONNEXIN 43 GENE EXPRESSION AFTER ACUPOINTS AND ACUPUNCTURE TREATMENT FOR PRIMARY DYSMENORRHEA

Objective To investigate the effect of acupuncture treatment on silencing the expression of Oonnexin 43 （Cx43）, and to study the analgesic mechanism of acupuncture treatment for primary dysmenorrhea （PD） in rats. Methods We used estrostilben to develop the model of primary dysmenorrhea in rat, and RNA interference technology to silence the expression of Cx43 in acupoints. Fifty female rats were randomly divided into five groups （n = 10 in each group） ： normal, model, acupuncture, acupuncture ＋ interference and acupuncture＋ interference control group, pSilencer-Cx43-shRNA and pSilencer-Oon-shRNA were injected locally into the acupoints in interference group and interference-control group, respectively. The incidence rate of writhe reaction over the period of 30 min was evaluated. The expression of the oxytocin receptor （OTR） and vasopressin receptor（VasR） in rat myometrium with Semiquantitative RT-POR and immunohistochemistry. Results （1）The mRNA and protein level of Cx43 in acupoints in interference group were significantly lower those of in the acupuncture group （P〈0.05）. There was no significant difference between acupuncture and interference-control group. （2） Acupuncture could significantly prolong the latency period of writhing body and decrease the number of writhing body as compared with that of model group and interference group. （3）The level of OTR and VasR mRNA and protein in the model group were significantly higher （P〈0.05） as compared to normal group. The results in acupuncture group and interference-control group were similar to the normal group. The results in interference group were similar to the model group. Conclusions Acupuncture may be useful in the treatment of the model of primary dysmenorrhea in the rats. Local injection of Cx43 shRNA expression vetor could silence the expression of Cx43 in acupoint and markedly influence acupuncture effect, demonstrating Cx43 is involved in acupuncture effect.

Effect of heating time on bonding interface, atom diffusion and mechanical properties of dissimilar titanium joints produced by thermal self-compressing bonding

Solid-state bonding between pure titanium and Ti6Al4V(TC4)alloy was conducted by a new bonding method named as rigid restraint thermal self-compressing bonding.Effects of heating time on bonding interface,atom diffusion and mechanical properties of the joints were studied.Results show that atom diffusion between pure titanium and TC4 alloy significantly takes place during bonding.The diffusion depths of Al and V in pure titanium side are increased with increasing heating time.Due to the enhancement of atom diffusion,bond quality of the bonding interface is improved along with the increase of heating time.The heating time seems to have little effect on microhardness distribution across the joint.However,the tensile strength and ductility of the joint have close relation to heating time.Prolonging heating time can improve the tensile strength and ductility of the joint,especially the latter.When the heating time increases to 450 s,solid-state joint with good combination of strength and ductility is attained.

Effects of temperature change on elastic behavior of steel beams with semi-rigid connections

Based on the nonlinear displacement-strain relationship,the virtual work principle method was used to establish the nonlinear equilibrium equations of steel beams with semi-rigid connections under vertical uniform loads and temperature change.Considering the non-uniform temperature distribution across the thickness of beams,the formulas for stresses and vertical displacements were presented.On the basis of a flowchart for analysis of the numerical example,the effect of temperature change on the elastic behavior of steel beams was investigated.It is found that the maximal stress is mainly influenced by axial temperature change,and the maximal vertical displacement is principally affected by temperature gradients.And the effect of temperature gradients on the maximal vertical displacement decreases with the increase of rotational stiffness of joints.Both the maximal stress and vertical displacement decrease with the increase of rotational stiffness of joints.It can be concluded that the effects of temperature changes and rotational stiffness of joints on the elastic behavior of steel beams are significant.However,the influence of rotational stiffness becomes smaller when the rotational stiffness is larger.

A Quantitative Structure Property Relationship for Prediction of Flash Point of Alkanes Using Molecular Connectivity Indices

Many structure-property/activity studies use graph theoretical indices, which are based on the topological properties of a molecule viewed as a graph. Since topological indices can be derived directly from the molecular structure without any experimental effort, they provide a simple and straightforward method for property prediction. In this work the flash point of alkanes was modeled by a set of molecular connectivity indices （Х）, modified molecular connectivity indices （ ^mХ^v ） and valance molecular connectivity indices （ ^mХ^v ）, with ^mХ^v calculated using the hydrogen perturbation. A stepwise Multiple Linear Regression （MLR） method was used to select the best indices. The predicted flash points are in good agreement with the experimental data, with the average absolute deviation 4.3 K.

Absolute Exponential Stability of Generalized Dynamical Neural Networks

This paper investigates the absolute exponential stability of generalized neural networks with a general class of partially Lipschitz continuous and monotone increasing activation functions. The main obtained result is that if the interconnection matrix T of the neural system satisfies that - T is an H matrix with nonnegative diagonal elements, then the neural system is absolutely exponentially stable(AEST). The Hopfield network, Cellular neural network and Bidirectional associative memory network are special cases of the network model considered in this paper. So this work gives some improvements to the previous ones.

Dielectrophoretic assembly of semiconducting single-walled carbon nanotube transistor

A novel burning technique for making a semiconducting single-walled carbon nanotubes （SWNTs） transistor assembled by the dielectrophoretic force was suggested. The fabrication process consisted of two steps. First, to align and attach a bundle of SWNTs between the source and drain, the alternating （AC） voltage was applied to the electrodes. When a bundle of SWNTs was connected between two electrodes, some of metallic nanotubes and semi-conducing nanotubes existed together. The second step is to burn the metallic SWNTS by applying the voltage between two electrodes. With increasing the voltage, more current flowed through the metallic SWNTs, thus, the metallic SWNTs burnt earlier than the semiconducting one. This technique enables to obtain only semi-conducting SWNTs connection in the transistor. Through the 1--V characteristic graph, the moment of metallic SWNTs burning and the characteristic of semi-conducing nanotubes were verified.

Influences of gap size and cyclic-thermal-shock treatment on mechanical properties of TLP bonded IN-738LC superalloy

Influences of gap size and cyclic-thermal-shock treatment on the mechanical properties of transient liquid phase（TLP） bonded IN-738 LC superalloy were investigated. For this purpose, TLP bonding of IN-738 LC superalloy was carried out in a vacuum furnace using powdered AMS 4777 as the filler metal. The results showed that isothermal solidified zone（ISZ） consisted of Ni solid-solution and the distribution of alloying elements was homogeneous. High hardness of HV 409 and high shear strength of 506 MPa were observed in 40 μm gap sample. Alloying elements formed γ′ precipitates and the solid-solution in the ISZ. Hardness and shear strength of bonds were reduced with increasing the gap size（in range of 40-120 μm）. The fractured surfaces of complete isothermal solidified bonds showed dimpled rupture, but athermal solidified bonds showed cleavage fracture surface. 10, 20, 30 and 40 thermal-shock cycles were applied to 80 μm gap samples, respectively. The shear strength of the bond was measured to be 268 MPa after the 40 th thermal-shock cycle. The sample with gap size of 80 μm was failed due to crack nucleation on faying surface at 45 th thermal-shock cycle. The amount of the produced brittleness due to quenching the samples in water bath was attributed to the number of thermal-shock cycles.

Joint Non-Orthogonal Multiple Access (NOMA) & Walsh-Hadamard Transform: Enhancing the Receiver Performance

Non-orthogonal multiple access(NOMA) is a new access method to achieve high performance gains in terms of capacity and throughput, so it is currently under consideration as one of the candidates for fifth generation(5 G) technologies. NOMA utilizes power domain in order to superimpose signals of multiple users in a single transmitted signal. This creates a lot of interference at the receive side. Although the use of successive interference cancellation(SIC) technique reduces the interference, but to further improve the receiver performance, in this paper, we have proposed a joint Walsh-Hadamard transform(WHT) and NOMA approach for achieving better performance gains than the conventional NOMA. WHT is a well-known code used in communication systems and is used as an orthogonal variable spreading factor(OVSF) in communication systems. Application of WHT to NOMA results in low bit error rate(BER) and high throughput performance for both low and high channel gain users. Further, it also reduces peak to average power ratio(PAPR) of the user signal. The results are discussed in terms of comparison between the conventionalNOMA and the proposed technique, which shows that it offers high performance gains in terms of low BER at different SNR levels, reduced PAPR, high user throughput performance and better spectral efficiency.

LINK PERDURABILITY BASED ROUTING FOR MOBILE AD HOC NETWORKS

Ad Hoc networks are prone to link failures due to mobility. In this letter, a link perdurability based routing scheme is proposed to try dealing with this problem. This scheme uses signal strength measurements to estimate the route life time and hence chooses a stable route, and is implemented in two typical ad hoc routing protocols to evaluate its performance. The simulation results have shown that this scheme can improve these protocols' packet delivery ratio in cases where there are frequent link failures.

Multiple Resonance and Stability of a Motor-elastic Linkage Mechanism System

The dynamics of a three-phase AC motor-elastic linkage mechanism system is considered. Taking the drive motor and the linkage mechanism as an integrated system, the coupling dynamic equations of the system are established by the finite element method. The multiple resonance and its stability of the system are studied using the method of multiple scales. The first order approximate solutions of the multiple resonance of the system are obtained. An algorithm for determining the stability of resonance is derived. The studies show that the multiple resonance and its stability of the system are not only related to the structure parameters of the linkage mechanism, but also to the electromagnetism parameters of the motor. At last, an experiment is given to verify the results of the theoretical analysis.

Concave Minimization for Sparse Solutions of Absolute Value Equations

Based on concave function, the problem of finding the sparse solution of absolute value equations is relaxed to a concave programming, and its corresponding algorithm is proposed, whose main part is solving a series of linear programming. It is proved that a sparse solution can be found under the assumption that the connected matrixes have range space property(RSP). Numerical experiments are also conducted to verify the efficiency of the proposed algorithm.

Development of Chinese large-scale space end-effector

In order to achieve large tolerance capture and high stiffness connection for space payload operations,a Chinese large-scale space end-effector (EER) was developed.Three flexible steel cables were adopted to capture the payload with large capture allowance.Ball screw transmission mechanism and plane shape-constraint four bar linkage mechanism were utilized to connect the payload with high stiffness.The experiments show that capture tolerances in X,Y,Z,Pitch,Yaw,Roll directions are 100 mm,100 mm,120 mm,10.5°,10.5°,12°,respectively.The maximum connection stiffness is 4 800 N·m.The end-effector could meet the requirements for space large tolerance capture and high stiffness connection in the future.

Stability of mine ventilation system based on multiple regression analysis

In order to overcome the disadvantages of diagonal connection structures that are complex and for which it is difficult to derive the discriminant of the airflow directions of airways, we have applied a multiple regression method to analyze the effect, of changing the rules of mine airflows, on the stability of a mine ventilation system. The amount of air （ Qj ） is determined for the major airway and an optimum regression equation was derived for Qi as a function of the independent variable （ Ri ）, i.e., the venti- lation resistance between different airways. Therefore, corresponding countermeasures are proposed according to the changes in airflows. The calculated results agree very well with our practical situation, indicating that multiple regression analysis is simple, quick and practical and is therefore an effective method to analyze the stability of mine ventilation systems.

Quantum Dynamics of Two Capacitively Coupled Superconducting Islands via josephson Junctions

In this paper, we consider a system consisting of two capacitively coupled superconducting islands viaJosephson junctions. We show that it can be reduced to two coupling harmonic oscillators under certain conditions,and can be solved exactly in terms of a displacing transformation, a beam-splitter-like transformation, and a squeezingtransformation. It is found that the system evolves by a rotated-squeezed-coherent state when the system is initially in acoherent state. Quantum dynamics of the Cooper pairs in the two superconducting islands are investigated. It is shownthat the number of the Cooper pairs in the two islands evolves periodically.

Structure realization method for collapse threshold of plastic deformation in train collision condition

To protect passengers, absorb enough kinetic energy and meet the special requirements for trains which are different from the other means of transportation, a method is presented to realize the plastic deformation threshold based on three main aspects of train connection structure, crashworthy vehicle structure, energy-absorbing component. In practical engineering, trains need enough strength and stiffness to transfer longitudinal force under the normal operation condition, and have to produce controllable large plastic dcfbrmation to absorb energy shortly under the collision condition. To realize the structural damage threshold of connecting structure in terminal end, two control methods are also proposed which can be divided as the parametric method based on ＇extrusion＇ and ＇cutting＇ theories; the method which can cut the connecting components between coupler-buffer devices and train bodies and separate them away when the damage thresholds of coupler-buffer devices are more than the pre-supposed damage thresholds. The damage thresholds can be realized based on changing the parameters of the number of shearing bolts, material parameters, etc. To realize the collision threshold of energy-absorbing components of trains, a control method is presented based on the ways of setting plastic deformation induced structure, local hole and pre-deformation structure. To realize the threshold of the controllable plastic structure of energy-absorbing vehicles, a control method is proposed for the multi-level longitudinal stiffness of train terminal structures.

Nonlinear identification and characterization of structural joints based on vibration transmissibility

In order to investigate the nonlinear characteristics of structural joint,the experimental setup with a jointed mass system is established for dynamic characterization analysis and vibration prediction,and a corresponding nonlinearity identification method is studied.First,the sine-sweep vibration test with different baseexcitation levels areapplied to the structural joint system to study the dominant modal of mass rigid motion.Then,based on t e harmonic balance method principle,t e measured vibration transmissibilities a e utilized for nonlinearity identification using different excitation levels.Experimental results show that nonlinear spring and damping force can be represented by a polynomial order approximation.The identified nonlinear stiffness and damping force can predict the system’s response,and they can reveal t e shifts of resonant frequency or damping due to discontinuity of contact mechanisms within a certain range.