韦德规则预测XmSin原子簇稳定结构研究

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"The structures of XmSin by Wade's (2n +2) rules" 这篇论文主要探讨了韦德规则在预测XmSin原子簇稳定结构中的应用。韦德规则，也称为2n+2规则，是一种在多面体硼原子簇几何构型和电子结构解析中广泛使用的理论框架。该规则由化学家罗杰·韦德提出，能够有效地解释多面体硼簇的稳定几何形状。论文作者高爱梅通过对XSin-1- 和X2Sin-2 (X = P, As)的几何稳定结构进行B3LYP/6-311+G*方法的量子力学计算，验证了这一规则在磷和砷掺杂硅原子簇中的适用性。 B3LYP是一种混合密度泛函理论方法，结合了BLYP泛函与局域密度近似（LDA）交换势和非局域的Becke三参数Xα交换项，是化学计算中常用的一种理论模型。6-311+G*基组则是一个包含内层电子的基组，它在6-311G*基础上增加了d轨道的虚函数，提高了计算的精度，特别适合于描述分子的电子结构。 研究结果显示，磷和砷掺杂的硅负离子簇（PSin-1-, AsSin-1-, 和As2Sin-2）的基态结构可以通过韦德的2n+2规则得到。这一规则指出，稳定的多面体硼簇倾向于有2n+2个顶点，其中n代表多面体的不共面顶点数。通过计算，作者发现对于较小的P2Sin-2(n=5-9)簇，低能异构体的结构也符合这一设计原则，进一步证实了韦德规则的有效性。 韦德规则的应用不仅限于硼簇，论文表明它也可以成功地应用于硅原子簇中掺杂磷和砷的系统。这对于理解和预测异原子掺杂硅簇的稳定结构具有重要意义，特别是在材料科学和纳米技术领域，如电池材料和新型半导体材料的设计。通过理论计算，研究人员可以预先预测这些结构，从而指导实验合成，减少实验次数，提高研究效率。 高爱梅的研究深入探讨了韦德规则在预测异原子掺杂硅簇结构中的作用，强调了理论计算在理解复杂化学系统稳定性的关键角色，并为未来相关领域的研究提供了理论依据和方法指导。

Algorithms + Data Structures = Programs

2018-11-29 上传
Algorithms + Data Structures = Programs[1] is a 1976 book written by Niklaus Wirth covering some of the fundamental topics of computer programming, particularly that algorithms and data structures are...

The starting configuration of this puzzle is a row of cells, with disks located on cells through . The goal is to move the disks to the end of the row using a constrained set of actions. At each step, a disk can only be moved to an adjacent empty cell, or to an empty cell two spaces away if another disk is located on the intervening square. Given these restrictions, it can be seen that in many cases, no movements will be possible for the majority of the disks. For example, from the starting position, the only two options are to move the last disk from cell to cell , or to move the second-to-last disk from cell to cell . 1. [15 points] Write a function solve_identical_disks(length, n) that returns an optimal solution to the above problem as a list of moves, where length is the number of cells in the row and n is the number of disks. Each move in the solution should be a twoelement tuple of the form (from, to) indicating a disk movement from the cell from to the cell to. As suggested by its name, this function should treat all disks as being identical. Your solver for this problem should be implemented using a breadth-first graph search. The exact solution produced is not important, as long as it is of minimal length. Unlike in the previous two sections, no requirement is made with regards to the manner in which puzzle configurations are represented. Before you begin, think carefully about which data structures might be best suited for the problem, as this choice may affect the efficiency of your search

2023-06-06 上传
Here's a possible implementation of the `solve_identical_disks` function using breadth-first graph search: ```python from collections import deque def solve_identical_disks(length, n): # Initialize...

Optimize the performance of a slow-running function by profiling it with cProfile and identifying the bottlenecks.

2023-03-31 上传
By using cProfile to profile your code and identify bottlenecks, you can optimize the performance of slow-running functions and improve the overall efficiency of your Python programs.

in c language, what is the use of this formula after the colon:(n)&(n-1)

2023-03-31 上传
The size of the array is determined by adding "n" to the size of the structure. This allows us to create structures with variable-length arrays, which can be useful in certain situations where the ...

Consider two 4-bit binary numbers A and B. Bits of A are a3, a2, a1, and a0, and bits of B are b3, b2, b1, and b0. A is greater than B if a3 is 1 and b3 is 0, but if a3 and b3 are the same, then if a2 is 1 and b2 is 0, we can determine that A is greater than B. This evaluation continues until a0 and b0 are considered. If a0 and b0 are equal then A and B are equal. Using discrete gates and Verilog gate primitives build a 4-bit comparator that generates a 1 on its GT output when its 4-bit input A is greater than its B input, and a 1 on its EQ output when A and B are equal. Use the generate statement and other Verilog iterative logic support structures. The code should be as simple as possible.

2023-05-25 上传
Here's one possible implementation of the 4-bit comparator in Verilog: ``` module comparator ( input [3:0] A, input [3:0] B, output GT, output EQ ); wire [3:0] greater = {A[3] & ~B[3], A[3:2] > ...

翻译This SiO2 shell is a key component in the mechanism for reversible actuation, as illustrated by finite element analysis (FEA) in Fig. 1C. An increase in temperature transforms the SMA (nitinol) from the martensitic to the austenitic phase, causing the 3D structure to flatten into a 2D shape. The responses of the SMA elements at the joints act as driving forces to deform the PI skeleton. This process also elastically deforms the SiO2 shell, resulting in a counter force that limits the magnitude of the deformation. The change in shape ceases when the forces from the shell balance those from the joints (right frame in Fig. 1C). Upon a reduction in temperature, the SMA changes from the austenitic back to the martensitic phase, thereby reducing the force produced by the SMA at the joints to zero. The elastic forces associated with the shell then push the entire system back to the original 3D geometry (left frame in Fig. 1C). Figure S3A simulates the moments generated by the SMA and the SiO2 shell. In the FEA model, the SiO2 shell appears on both the outer and inner surfaces of the 3D robot, consistent with experiments (fig. S3B). Although a single layer of the SiO2 shell at the outer or inner surface can also provide restoring force, the double-layer shell structure follows naturally from the conformal deposition process. This actuation scheme allows for reversible shape transformations using a one-way shape memory material. Without the shell, the structure only supports a single change in shape, from 3D to 2D, as illustrated in fig. S3C. Figure 1D shows optical images of a freestanding 3D peekytoe crab on the edge of a coin, highlighting the preserved 3D geometry enabled by the SiO2 shell after release from the elastomer substrate. Other 3D structures in geometries that resemble baskets, circular helices, and double-floor helices also exhibit high shape storage ratios (>85%) after cycles of heating and cooling (fig. S4). This ratio (s) is defined as s = 1 − |L1 − L0|/L0 × 100%, where L0 and L1 are the distances between the bonding sites at both ends at the initial stage and subsequent stages, respectively

2023-06-13 上传
这个SiO2壳是可逆作用机制的关键组成部分，如图1C所示的有限元分析所示。温度的升高将SMA（尼钛）从...这个比率（εs）定义为εs = 1-|L1-L0|/L0×100%，其中L0和L1分别是初始阶段和随后阶段两端结合点之间的距离。

the origin and definition of "family"

2023-03-29 上传
The concept of family has existed for thousands of years, and its definition has evolved over time and across cultures. Generally, a family is a social unit consisting of people who are related to ...

Consider two 4-bit binary numbers A and B. Bits of A are a3, a2, a1, and a0, and bits of B are b3, b2, b1, and b0. A is greater than B if a3 is 1 and b3 is 0, but if a3 and b3 are the same, then if a2 is 1 and b2 is 0, we can determine that A is greater than B. This evaluation continues until a0 and b0 are considered. If a0 and b0 are equal then A and B are equal. Using discrete gates and Verilog gate primitives build a 4-bit comparator that generates a 1 on its GT output when its 4-bit input A is greater than its B input, and a 1 on its EQ output when A and B are equal. Use the generate statement and other Verilog iterative logic support structures.

2023-05-25 上传
Here's one possible ...Note that this implementation makes use of the `generate` statement implicitly by using the array index notation to generate the logic for each bit of the `greater` wire.

Use the generate statement and other Verilog iterative logic support structures.

2023-05-25 上传
For example, the following code uses a for loop and a generate statement to create eight instances of a simple 2-input AND gate: ``` module and_gate(input a, input b, output c); assign c = a & b; ...

翻译The complex 3D geometries of these submillimeter-scale robots originate from planar (2D) multilayer assemblies formed with deposition and patterning techniques used in the semiconductor industry. Figure 1 (A and B) illustrates the process of transformation that converts these 2D precursors into 3D shapes for the case of a design inspired by the geometry of a peekytoe crab (Cancer irroratus) but engineered to a much smaller dimensions (~1/150 of the actual size; fig. S1). The precursors incorporate layers of SMA (nitinol; 2.5 m in thickness) as a collection of dynamic mechanical joints for locomotion, a film of polyimide (PI; ~8 m in thickness) as a static skeleton for structural support, and pads of silicon dioxide (SiO2; 100 nm in thickness) as bonding sites in the 2D to 3D transformation process (left frames in Fig. 1, A and B). This process begins with transfer printing to deliver these 2D precursors onto the surface of a prestretched silicone elastomer (Dragon Skin 10 Slow, ~500 m in thickness) that supports structures of polydimethylsiloxane (PDMS; blocks) located near the claws and back legs (middle frame in Fig. 1B). Releasing the prestrain imposes compressive stresses at the bonding sites, with forces sufficient to convert the 2D structures into 3D architectures via a set of controlled bending/ twisting deformations and translational/rotational motions (31, 32). During this process, the distance between the two PDMS blocks also decreases, thereby deforming the claws and back legs. This transformation involves peak strains (<4%) that lie below the maximum phase transition strain of the SMA (right frame in Fig. 1B).

2023-06-12 上传
这些亚毫米级机器人的复杂三维几何形状源于半导体工业中使用的沉积和图案化技术形成的平面（二维）多层组装。图1（A和B）说明了转化过程，将这些二维前体转化为三维形状，以一个以peekytoe蟹（Cancer irroratus）...
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