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We have studied the reaction kinetics of Cu chemical vapor deposition (CVD) by H2 reduction of normalCufalse(normalhfa)2 in a horizontal flow, atmospheric pressure, hot‐wall CVD reactor. Using glass substrates, we can routinely deposit films at temperatures as low as 523 K and growth rates of 200 Å/min, with resistivities between 2–3 μΩ‐cm. The reactor is operated at integral conversions of normalCufalse(normalhfa)2 , and the reaction kinetics are determined by analyzing the axial thickness profiles of the deposited films obtained under a series of different operating conditions (e.g. reactant composition, substrate temperature, and carrier gas flow rate). The steady‐state growth rate exhibits saturation kinetics with respect to normalCufalse(normalhfa)2 concentration, positive reaction order with respect to H2 , and negative reaction order with respect to H(hfa). We propose a mechanism based on dissociative adsorption of normalCufalse(normalhfa)2 at vacant surface sites, followed by H‐atom assisted desorption of H(hfa) ligands as the rate limiting step in the overall reaction. The resulting rate expression is combined with a reactor model based on a one‐dimensional normalCufalse(normalhfa)2 species conservation equation, and the calculated thickness profiles are compared with observed results to obtain estimates of the kinetic parameters.

Postmastectomy radiotherapy (PMRT) has been shown to improve the overall survival for invasive breast cancer patients, and many advanced radiotherapy technologies were adopted for PMRT. The purpose of our study is to compare various advanced PMRT techniques including fixed-beam intensity-modulated radiotherapy (IMRT), non-coplanar volumetric modulated arc therapy (NC-VMAT), multiple arc VMAT (MA-VMAT), and tomotherapy (TOMO). Results of standard VMAT and mixed beam therapy that were published by our group previously were also included in the plan comparisons. Treatment plans were produced for nine PMRT patients previously treated in our clinic. The plans were evaluated based on planning target volume (PTV) coverage, dose homogeneity index (DHI), conformity index (CI), dose to organs at risk (OARs), normal tissue complication probability (NTCP) of pneumonitis, lifetime attributable risk (LAR) of second cancers, and risk of coronary events (RCE). All techniques produced clinically acceptable PMRT plans. Overall, fixed-beam IMRT delivered the lowest mean dose to contralateral breast (1.56 ± 0.4 Gy) and exhibited lowest LAR (0.6 ± 0.2%) of secondary contralateral breast cancer; NC-VMAT delivered the lowest mean dose to lungs (7.5 ± 0.8 Gy), exhibited lowest LAR (5.4 ± 2.8%) of secondary lung cancer and lowest NTCP (2.1 ± 0.4%) of pneumonitis; mixed beam therapy delivered the lowest mean dose to heart (7.1 ± 1.3 Gy) and exhibited lowest RCE (8.6 ± 7.1%); TOMO plans provided the most optimal target coverage while delivering higher dose to OARs than other techniques. Both NC-VMAT and MA-VMAT exhibited lower values of all OARs evaluation metrics compare to standard VMAT. Fixed-beam IMRT, NC-VMAT, and mixed beam therapy could be the optimal radiation technique for certain breast cancer patients after mastectomy.

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Handling the explosion of massive data not only requires signi cant improvements in information processing, storage and communication abilities of hardware but also demands higher security in the storage and communication of sensitive information. As a type of hardware-based security primitives, physically unclonable functions (PUFs) represent a promising emerging technology utilizing random imperfections existing in a physical entity, which cannot be predicted or cloned. However, if a PUF is exploited to carry out secure communication, the keys inside it must be written into non-volatile memory and then shared with other participants that do not hold the PUF, which makes the keys vulnerable. Here, we show that identical PUFs, e.g. twin PUFs can be fabricated on the same aligned carbon nanotube arrays and optimized to yield excellent uniformity, uniqueness, randomness, and reliability. The twin PUFs show a good consistency of approximately 95 % and are used to demonstrate secure communication with a bit error rate reduced to one trillion through a fault-tolerant design. As a result, our twin PUFs offering a convenient, low-cost and reliable new technology for guarantee information exchange security.

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Two-dimensional (2D) materials have attracted great interest due to their unique structures and exotic properties related to promising applications and fundamental research. Reducing the dimensionality of 2D materials into their 1D nanostructure is also highly desirable for the exploitation of novel properties and offers new research opportunities. In this work, we demonstrate a bottom-up synthesis of molybdenum disulfides (MoS 2 ) nanoribbons on graphene substrate via chemical vapor deposition (CVD) by precisely tuning the growth parameters into a sulfur-enriched condition. MoS 2 nanoribbons are mainly formed from the CVD grown MoS 2 flakes along the armchair (AC) direction. Atomic resolution ADF-STEM imaging characterizations show an alternating presence of molybdenum and sulfur zigzag edge terminations at the edges of MoS 2 nanoribbons. While at the apex of the nanoribbon, sulfur terminated zigzag edges become dominant. Taking these results together, we revealed the underlying growth mechanism of MoS 2 nanoribbons. Electronic transport properties of the MoS 2 nanoribbons were also measured by fabricating back-gate-effect transistors (FETs). The nanoribbon FETs present n-type behavior with a current on/off ratio higher than 10 4 at V DS =1 and a carrier mobility of 1.39 cm 2 V −1 s −1 . This work offers a new route to synthesize 1D MoS 2 nanoribbons, which has great potential in fabricating other 2D materials-derived 1D nanostructures.

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