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حرب الرقائق : فك رموز صناعة الرقائق الدقيقة في الصين : طبول الحرب تقرع على أبواب الشرائح الإلكترونية أشباه الموصلات
يستعرض الكتاب التقنيات الصينية في مجال صناعة الرقائق، والطرق التي اتبعتها بكين لتطوير تقنيات التصنيع المحلية، مع الاعتماد على الذكاء الاصطناعي والمواد المتقدمة. يستعرض المؤلف تفاصيل حول الشركات الصينية الكبرى التي تتنافس لتصنيع الشرائح الإلكترونية بمستوى عال من الدقة. التهديدات الجيوسياسية لا تقتصر حرب الرقائق على الابتكار فقط، بل تشمل أيضا معركة جيوسياسية، حيث تستمر الدول الكبرى في وضع العقوبات و الضغوط الاقتصادية على بعض الشركات الصينية التي تعتبر منافسا رئيسيا الابتكارات في مجال الرقائق الدقيقة الكتاب يتطرق إلى مستقبل الرقائق الدقيقة والشرائح الإلكترونية، مع تسليط الضوء على الابتكارات في تقنيات التصنيع مثل الشرائح ثلاثية الأبعاد و تقنيات النانو، التي من شأنها تغيير شكل صناعة التكنولوجيا في المستقبل القريب. التأثير على الاقتصاد العالمي كيف يمكن لصناعة الرقائق أن تحدد اقتصاديات الدول الكبرى، وكيف أن أي تعطيل لهذه الصناعة قد يؤثر على أسواق الهواتف الذكية، السيارات الكهربائية، الذكاء الاصطناعي، الأجهزة الطبية، والكثير من الصناعات التي تعتمد على الأجهزة الإلكترونية الدقيقة.
BOOK
Universal non-Hermitian skin effect in two and higher dimensions
Skin effect, experimentally discovered in one dimension, describes the physical phenomenon that on an open chain, an extensive number of eigenstates of a non-Hermitian Hamiltonian are localized at the end(s) of the chain. Here in two and higher dimensions, we establish a theorem that the skin effect exists, if and only if periodic-boundary spectrum of the Hamiltonian covers a finite area on the complex plane. This theorem establishes the universality of the effect, because the above condition is satisfied in almost every generic non-Hermitian Hamiltonian, and, unlike in one dimension, is compatible with all point-group symmetries. We propose two new types of skin effect in two and higher dimensions: the corner-skin effect where all eigenstates are localized at corners of the system, and the geometry-dependent-skin effect where skin modes disappear for systems of a particular shape, but appear on generic polygons. An immediate corollary of our theorem is that any non-Hermitian system having exceptional points (lines) in two (three) dimensions exhibits skin effect, making this phenomenon accessible to experiments in photonic crystals, Weyl semimetals, and Kondo insulators.
The non-Hermitian skin effect has been discovered in a one dimensional open chain. Here, the authors establish the universality of this effect in two and higher dimensional non-Hermitian systems and propose two new types of skin effect.
Journal Article
الخزف الصيني
عل الكثير لا يعرفون أن اسم الصين في كل لغات العالم يرتبط بكلمة الخزف منذ أطلق عليها هذا الاسم في مصر القديمة عندما بدئت الرحلات التجارية الصينية عبر طريق الحرير، كما أن الخزف الصيني الذي لا يخلو بيت في العالم منه هو أبرز علامات تفوق الصين قديما وحديثا كما أنه من أقدم البضائع التجارية في العالم التي مارست الدول القديمة التجارة الدولية بها منذ عصر تبادل البضائع بالبضائع والخزف هو بوابة الصين التي دخلت من خلالها للعالم وعرفت به وعرف بها وظهور الخزف قديما يرمز إلى تطويع الإنسان لكل المواد الطبيعية التي يستخدمها وهي الماء والنار والطين، بل يثبت قدرة الإنسان على تغيير البيئة المادية وإضافة لمحات جمالية عالية إليها وفي هذا الكتاب يقدم لك فيه عزيزي القارئ قصة الخزف الصين منذ النشأة ومرورا بمراحل التطور حتى وصوله إلى قمة مستواه الفني والتجاري فنحن نقدم لك تلخيصا لتاريخ تطور الأمة الصينية وتقدم فنونها كما ستلمح بين سطوره الكثير من ملامح الثقافة الصينية وتتعرف على فكر وفلسفة الصينيين وحبهم للجمال ودقتهم في العمل بل ستربط من خلال هذا الكتاب الممتع بين صين الأمس المتطورة في الحرف اليدوية وأهمها الخزف وصين اليوم التي صار تفوقها الصناعي والتقني من معجزات العالم الحديث، كما ستكتشف العديد من المعلومات الشيقة حول الصين القديمة وتبادلاتها التجارية مع دول العالم.
Book
Quantitative mappings between symmetry and topology in solids
The study of spatial symmetries was accomplished during the last century and had greatly improved our understanding of the properties of solids. Nowadays, the symmetry data of any crystal can be readily extracted from standard first-principles calculation. On the other hand, the topological data (topological invariants), the defining quantities of nontrivial topological states, are in general considerably difficult to obtain, and this difficulty has critically slowed down the search for topological materials. Here we provide explicit and exhaustive mappings from symmetry data to topological data for arbitrary gapped band structure in the presence of time-reversal symmetry and any one of the 230 space groups. The mappings are completed using the theoretical tools of layer construction and symmetry-based indicators. With these results, finding topological invariants in any given gapped band structure reduces to a simple search in the mapping tables provided.
The defining quantities of topological materials—the topological invariants—are often difficult to calculate. Here, Song et al. report a simplified method to calculate both the symmetry data and the topological invariants for arbitrary gapped band structure with time-reversal symmetry.
Journal Article
أسرار التنمية الاقتصادية الصينية
هذا الكتاب يقدم عرضا شاملا لأسرار التنمية الاقتصادية في الصين، خلال ما يزيد على ربع قرن من الزمان ويحكي تجربتها وخبرتها، مستخدما مفاهيم الاقتصاد الدولي ؛ ويؤكد أن الاشتراكية ذات الخصائص الصينية ثروة ثمينة للفكر الإنساني، مما يجعل هذا الكتاب مرجعا بالغ الأهمية لكل الباحثين الأكاديميين وكل قارئ عربي مهتم بمعرفة أسرار ما حدث في الصين وسبر أغوار اقتصادها.
BOOK
Comparing Methods for Segmenting Supra-Glacial Lakes and Surface Features in the Mount Everest Region of the Himalayas Using Chinese GaoFen-3 SAR Images
Glaciers and numerous glacial lakes that are produced by glacier melting are key indicators of climate change. Often overlooked, supra-glacial lakes develop in the melting area in the low-lying part of a glacier and appear to be highly variable in their size, shape, and location. The lifespan of these lakes is thought to be quite transient, since the lakes may be completely filled by water and burst out within several weeks. Changes in supra-glacial lake outlines and other surface features such as supra-glacial rivers and crevasses on the glaciers are useful indicators for the direct monitoring of glacier changes. Synthetic aperture radar (SAR) is not affected by weather and climate, and is an effective tool for study of glaciated areas. The development of the Chinese GaoFen-3 (GF-3) SAR, which has high spatial and temporal resolution and high-precision observation performance, has made it possible to obtain dynamic information about glaciers in more detail. In this paper, the classical Canny operator, the variational B-spline level-set method, and U-Net-based deep-learning model were applied and compared to extract glacial lake outlines and other surface features using different modes and Chinese GF-3 SAR imagery in the Mount Everest Region of the Himalayas. Particularly, the U-Net-based deep-learning method, which was independent of auxiliary data and had a high degree of automation, was used for the first time in this context. The experimental results showed that the U-Net-based deep-learning model worked best in the segmentation of supra-glacial lakes in terms of accuracy (Precision = 98.45% and Recall = 95.82%) and segmentation efficiency, and was good at detecting small, elongated, and ice-covered supra-glacial lakes. We also found that it was useful for accurately identifying the location of supra-glacial streams and ice crevasses on glaciers, and quantifying their width. Finally, based on the time series of the mapping results, the spatial characteristics and temporal evolution of these features over the glaciers were comprehensively analyzed. Overall, this study presents a novel approach to improve the detection accuracy of glacier elements that could be leveraged for dynamic monitoring in future research.
Journal Article
Diagnosis for Nonmagnetic Topological Semimetals in the Absence of Spin-Orbital Coupling
Topological semimetals are under intensive theoretical and experimental studies. The first step of these studies is always the theoretical (numerical) predication of one or several candidate materials, based on first-principles numerics. In these calculations, it is crucial that all topological band crossings, including their types and positions in the Brillouin zone, are found. While band crossings along high-symmetry lines, which are routinely scanned in numerics, are simple to locate, the ones at generic momenta are notoriously time-consuming to find and may be easily missed. In this paper, we establish a theoretical scheme of diagnosis for topological semimetals where all band crossings are at generic momenta in systems with time-reversal symmetry and negligible spin-orbital coupling. The scheme uses only the symmetry (inversion and rotation) eigenvalues of the valence bands at high-symmetry points in the Brillouin zone as input and provides the types (lines or points), topological charges, numbers, and configurations of all robust topological band crossings, if any, at generic momenta. The nature of the new diagnosis scheme allows for full automation and parallelization and paves the way to high-throughput numerical predictions of topological semimetals.
Journal Article
Entanglement wedge reconstruction using the Petz map
A
bstract
At the heart of recent progress in AdS/CFT is the question of subregion duality, or entanglement wedge reconstruction: which part(s) of the boundary CFT are dual to a given subregion of the bulk? This question can be answered by appealing to the quantum error correcting properties of holography, and it was recently shown that robust bulk (entanglement wedge) reconstruction can be achieved using a universal recovery channel known as the
twirled Petz map
. In short, one can use the twirled Petz map to recover bulk data from a subset of the boundary. However, this map involves an averaging procedure over bulk and boundary modular time, and hence it can be somewhat intractable to evaluate in practice. We show that a much simpler channel, the Petz map, is sufficient for entanglement wedge reconstruction for any code space of fixed finite dimension — no twirling is required. Moreover, the error in the reconstruction will always be non-perturbatively small. From a quantum information perspective, we prove a general theorem extending the use of the Petz map as a general-purpose recovery channel to subsystem and operator algebra quantum error correction.
Journal Article
Adipocyte-Derived Exosomes Carrying Sonic Hedgehog Mediate M1 Macrophage Polarization-Induced Insulin Resistance via Ptch and PI3K Pathways
Background/Aims: Adipocyte-derived exosomes (ADEs) stimulate the activation of macrophages and contribute to the development of insulin resistance. Sonic Hedgehog (Shh) is an exosome-carrying protein and stimulates macrophages to secrete inflammatory cytokines. However, the impact of ADEs carrying Shh on the pro-inflammatory activation of macrophages and consequently, adipocyte insulin resistance is unclear. Methods: 3T3-L1 adipocytes were cultured with high glucose and insulin to imitate the pathogeny of insulin resistance. ADEs were isolated from conditioned media of 3T3-L1 adipocytes via differential ultracentrifugation. We explored the role of ADEs carrying Shh in the polarization of macrophages by flow cytometry. Western blot and electrophoretic mobility shift assay (EMSA) were performed to determine the activation of Shh-mediated signalling pathways. The effects of ADE-treated macrophages on adipocyte insulin signalling were studied by Western blot. Results: We found that circulating Shh-positive exosomes were increased in type 2 diabetes patients. High glucose and insulin increased the secretion of Shh-positive ADEs. The ADEs carrying Shh induced pro-inflammatory or M1 polarization of bone marrow-derived macrophages (BMDM) and RAW 264.7 macrophages. Inhibitors of Ptch and PI3K blocked the M1 polarization induced by ADEs, which suggests that ADEs carrying Shh mediated M1 macrophage polarization through the Ptch/PI3K signalling pathway. ADE-treated RAW 264.7 macrophages were subsequently used to assess the effect on insulin signalling in adipocytes. Using a co-culture assay, we showed that both ADE-treated macrophages and exosomes from these macrophages could decrease the expression of insulin-resistant substrate-1 (IRS-1) and hormone-sensitive lipase (HSL) in adipocytes. Inhibitors of Ptch and PI3K blocked the down-regulation of IRS-1 and HSL induced by ADE-treated macrophages. Conclusion: Together, these data indicate that ADEs carrying Shh induce the M1 polarization of macrophages, which contributes to insulin resistance in adipocytes through the Ptch/PI3K pathway.
Journal Article