59 research outputs found
A Unified Quantitative Model of Vision and Audition
We have put forwards a unified quantitative framework of vision and audition,
based on existing data and theories. According to this model, the retina is a
feedforward network self-adaptive to inputs in a specific period. After fully
grown, cells become specialized detectors based on statistics of stimulus
history. This model has provided explanations for perception mechanisms of
colour, shape, depth and motion. Moreover, based on this ground we have put
forwards a bold conjecture that single ear can detect sound direction. This is
complementary to existing theories and has provided better explanations for
sound localization.Comment: 7 pages, 3 figure
Motor Learning Mechanism on the Neuron Scale
Based on existing data, we wish to put forward a biological model of motor
system on the neuron scale. Then we indicate its implications in statistics and
learning. Specifically, neuron firing frequency and synaptic strength are
probability estimates in essence. And the lateral inhibition also has
statistical implications. From the standpoint of learning, dendritic
competition through retrograde messengers is the foundation of conditional
reflex and grandmother cell coding. And they are the kernel mechanisms of motor
learning and sensory motor integration respectively. Finally, we compare motor
system with sensory system. In short, we would like to bridge the gap between
molecule evidences and computational models.Comment: 8 pages, 4 figure
Neural Mechanism of Language
This paper is based on our previous work on neural coding. It is a
self-organized model supported by existing evidences. Firstly, we briefly
introduce this model in this paper, and then we explain the neural mechanism of
language and reasoning with it. Moreover, we find that the position of an area
determines its importance. Specifically, language relevant areas are in the
capital position of the cortical kingdom. Therefore they are closely related
with autonomous consciousness and working memories. In essence, language is a
miniature of the real world. Briefly, this paper would like to bridge the gap
between molecule mechanism of neurons and advanced functions such as language
and reasoning.Comment: 6 pages, 3 figure
A Quantitative Neural Coding Model of Sensory Memory
The coding mechanism of sensory memory on the neuron scale is one of the most
important questions in neuroscience. We have put forward a quantitative neural
network model, which is self organized, self similar, and self adaptive, just
like an ecosystem following Darwin theory. According to this model, neural
coding is a mult to one mapping from objects to neurons. And the whole cerebrum
is a real-time statistical Turing Machine, with powerful representing and
learning ability. This model can reconcile some important disputations, such
as: temporal coding versus rate based coding, grandmother cell versus
population coding, and decay theory versus interference theory. And it has also
provided explanations for some key questions such as memory consolidation,
episodic memory, consciousness, and sentiment. Philosophical significance is
indicated at last.Comment: 9 pages, 3 figure
A Quantitative Neural Coding Model of Sensory Memory\ud
The coding mechanism of sensory memory on the neuron scale is one of the most\ud
important questions in neuroscience. We have put forward a quantitative neural network model,\ud
which is self-organized, self-similar, and self-adaptive, just like an ecosystem following\ud
Darwin's theory. According to this model, neural coding is a āmult-to-oneāmapping from\ud
objects to neurons. And the whole cerebrum is a real-time statistical Turing Machine, with\ud
powerful representing and learning ability. This model can reconcile some important disputations,\ud
such as: temporal coding versus rate-based coding, grandmother cell versus population coding,\ud
and decay theory versus interference theory. And it has also provided explanations for some key\ud
questions such as memory consolidation, episodic memory, consciousness, and sentiment.\ud
Philosophical significance is indicated at last.\u
2D Covalent Organic Frameworks as Intrinsic Photocatalysts for Visible Light-Driven COMsub\u3e2\u3c/sub\u3e Reduction
Covalent organic framework (COF) represents an emerging class of porous materials that have exhibited great potential in various applications, particularly in catalysis. In this work, we report a newly designed 2D COF with incorporated Re complex, which exhibits intrinsic light absorption and charge separation (CS) properties. We show that this hybrid catalyst can efficiently reduce CO2 to form CO under visible light illumination with high electivity (98%) and better activity than its homogeneous Re counterpart. More importantly, using advanced transient optical and X-ray absorption spectroscopy and in situ diffuse reflectance spectroscopy, we unraveled three key intermediates that are responsible for CS, the induction period, and rate limiting step in catalysis. This work not only demonstrates the potential of COFs as next generation photocatalysts for solar fuel conversion but also provide unprecedented insight into the mechanistic origins for light-driven CO2 reduction
Selective Excited-State Dynamics in a Unique Set of Rationally Designed Ni Porphyrins
In this work, we report the design and photophysical properties of a unique class of Ni porphyrins, in which the tert-butyl benzene substituents at the meso positions of the macrocycle were tethered by ethers with alkyl linkers. This not only results in the permanently locked ruf distortion of the macrocycle but also enables the engineering of the degree of distortion through varying the length of alkyl linkers, which addressed the complication of uncertainty in the specific structural distortions that has long plagued the porphyrin photophysical community. Using advanced time-resolved optical and X-ray absorption spectroscopy, we observed tunability in the excited-state relaxation pathway depending on the degree of distortion and characterized the associated transient intermediate structure. These findings provide a new avenue to afford accessibility to a wide range of excited-state properties in nonplanar porphyrins
Research status of stability in dynamic process of laser-arc hybrid welding based on droplet transfer behavior : a review
With the synergistic effect of laser and arc heat sources, laser-arc hybrid welding (LAHW) technology can improve welding speed and penetration depth, and enhance gap-bridging ability. This review describes the fundamental concepts and characteristics of droplet transfer behavior in LAHW. Emphasis was placed on the physical interaction between the laser and arc and the effect of the combined laser/arc heat sources on the welding process. However, the physical understanding of these multivariable and complex interactions is still evolving. Through numerous research findings and summary, it is found that there are several critical factors, including the laser-to-arc distance, heat source leading mode, shielding gas composition, and laser power, affecting the droplet transfer characteristics. This review critically interprets the latest development in the basic understanding of LAHW. It lays great stress on the coupling effect of laser and arc in droplet transfer dynamic process of LAHW, and offers a direction for the future study and progress of LAHW. Significant fields for future research are also confirmed
Automatic Extraction of Protein Interaction in Literature
Protein-protein interaction extraction is the key precondition of the
construction of protein knowledge network, and it is very important for the
research in the biomedicine. This paper extracted directional protein-protein
interaction from the biological text, using the SVM-based method. Experiments
were evaluated on the LLL05 corpus with good results. The results show that
dependency features are import for the protein-protein interaction extraction
and features related to the interaction word are effective for the interaction
direction judgment. At last, we analyzed the effects of different features and
planed for the next step.Comment: This paper has been withdrawn by the author due to its lack of
academic valu
- ā¦