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Quantum key distribution allows remote parties to generate information-theoretic secure keys. The bottleneck throttling its real-life applications lies in the limited communication distance and key generation speed, due to the fact that the information carrier can be easily lost in the channel. For all the current implementations, the key rate is bounded by the channel transmission probabilityη. Rather surprisingly, by matching the phases of two coherent states and encoding the key information into the common phase, this linear key-rate constraint can be overcome—the secure key rate scales with the square root of the transmission probabilityO(η) , as proposed in twin-field quantum key distribution [M. Lucamarini et al. Overcoming the Rate–Distance Limit of Quantum Key Distribution without Quantum Repeaters, Nature (London) 557, 400 (2018)]. To achieve this, we develop an optical-mode-based security proof that is different from the conventional qubit-based security proofs. Furthermore, the proposed scheme is measurement device independent; i.e., it is immune to all possible detection attacks. The simulation result shows that the key rate can even exceed the transmission probabilityηbetween two communication parties. In addition, we apply phase postcompensation to devise a practical version of the scheme without phase locking, which makes the proposed scheme feasible with the current technology. This means that quantum key distribution can enjoy both sides of the world—practicality and security.

In order to lower muzzle vibration, the major caliber gun reduced the recoil resistance in the in_bore period. When the recoil brake was designed, throttling area was enlarged to reduce the hydraulic resistance. This made the counterrecoil throttling chamber (III chamber) was unfilled in the beginning of recoil. In the middle of recoil, III chamber was filled all of a sudden. This made the pressure in the working chamber (I chamber) and III chamber and the recoil resistance increase sharply. According to the equation, Hydraulic equation of recoil brake was set up when the III chamber was unfilled. The conditon of that III chamber was unfilled was deduced. Recoil mechanism was designed in this algorithm, and the recoil motion was computed in compare to the tested curevs. The result indicated that computation result matched well with the actual test result. This study offered reference of design of this kind of recoil mechanism.

Three‐dimensional networks‐on‐chip are beneficial for performance improvement, but suffer from severe thermal issues. Dynamic thermal management (DTM) schemes have been proposed to keep the temperature below the thermal limit while improve the system performance. However, existing fully‐throttling DTM schemes degrade the network availability and thus decrease the system performance. In this study, a novel collaborative fuzzy‐based partially‐throttling DTM (CFP‐DTM) scheme is developed. Two main components are involved in the CFP‐DTM: (i) a fuzzy‐based clock gating scheme dynamically adjusting the throttling ratio and throttled nodes (ii) a highly adaptive throttling‐aware routing scheme for packets to detour the easily congested channels. Experiments show that, compared with the fully‐throttling based vertical throttling scheme, the proposed CFP‐DTM can improve the throughput by 27.5% and reduce the thermal control oscillation by 3°C under the maximum system workload.

During deep and ultra-deep well drilling operations, the throttling performance of the hydraulic-while-drilling jar is significantly affected by the combined influence of temperature-induced differential thermal expansion among components and changes in the rheological properties of hydraulic oil. These effects often lead to unstable jarring behavior or even complete failure to trigger jarring during stuck pipe events. Here, we propose a high-temperature degradation evaluation model for the throttling performance of the throttle valve in an HWD jar based on thermal expansion testing of individual components and high-temperature rheological experiments of hydraulic oil. By using the variation characteristics of the throttling passage geometry as a linkage, this model integrates the thermo-mechanical coupling of the valve body with flow field simulation. Numerical results reveal that fluid pressure decreases progressively along the flow path through the throttle valve, while flow velocity increases sharply at the channel entrance and exhibits mild fluctuations within the throttling region. Under fluid compression, the throttling areas of both the upper and lower valves expand to some extent, with their spatial distributions closely following the pressure gradient and decreasing gradually along the flow direction. Compared with ambient conditions, thermal expansion under elevated temperatures causes a more pronounced increase in throttling area. Additionally, as hydraulic oil viscosity decreases with increasing temperature, flow velocities and mass flow rates rise significantly, leading to a marked deterioration in the throttling performance of the drilling jar under high-temperature downhole conditions.

Traditional home automation is inconvenient for aging people. Biometric based personalized smart phone secures smart home automation. Internet of Things (IoT) is envisioned as a promising solution in the thrusting arenas of healthcare, industries, home automation and other domains due to its significant contribution towards connectivity, security, sleek design, low power, low cost and low workforce. This has come a long way industrially and is making an impact in the domestic market after Covid-19 pandemic. Social distancing and contact less solution is the need of the hour. Life style of people has changed from home to workplace such as remote monitoring, collaborative online work-place and online classes. This has increased the economic status of the home automation products manufacturing industry. User Authenticated Smart Home Automation with Healthcare Architecture considers security along with healthcare. This takes into account IoT reusable design concept that uses in-built user specific biometrics in smart phone for secured authentication. IoT based electronics and electrical devices are remotely monitored. The user activity is monitored and archived for future retrieval. An ambient temperature is maintained to make sure that the devices are operated in near ideal circumstances to avoid thermal throttling and this extends the lifetime of the devices. Thermal throttling causes serious threats to the devices and to the human being. In the proposed User Authenticated Smart Home Automation System with Healthcare, smart home is secured using user specific biometric authentication; sanitizer is provided and temperature is measured on entry; thermal throttling due to devices is prevented by maintaining the room temperature thereby providing healthcare.

Pump-controlled hydraulic circuits are more efficient than conventional valve-controlled ones. Pump-controlled hydraulic circuits for double rod cylinders are well developed and, presently, implemented in many applications including aviation. Nevertheless, current pump-controlled hydraulic circuits for single-rod cylinders encounter performance issues during specific operating conditions. Pressure and actuator velocity oscillations are encountered when operating in this critical zone. Different concepts, techniques and designs are proposed by researchers to overcome such vibration issues. In this research, three different concepts to overcome the reported oscillation problem in these circuits are presented; namely: (1) shifting of critical zone into lower loading ranges, (2) applying selective leakage, and (3) applying selective throttling. Simulation studies indicated that the new concepts alleviated the oscillation issue of the common pump-controlled circuits, and improved their performances. The second and third concepts, in particular, were capable of eliminating the whole critical zone. The first concept reduced the area of the critical zone in the load-velocity plane and lessened undesirable effect of oscillations. Simulation studies further proved the enhanced performance of circuits that applies these concepts as compared to previously-designed circuits.

Downhole throttling technology is of great significance to the stable production of natural gas. Downhole throttle is widely used by major oil and gas fields. In view of the frequent failure of downhole throttle, downhole throttling mechanism and relevant literature on downhole throttle failure were studied and analyzed. It is concluded that: (1) structural failure of downhole throttle mainly occurs in the rubber cylinder, slip and throttle nozzle; (2) under the condition of satisfying the strength of slip and rubber cylinder, it is necessary to further study and analyze the problem that jamming of slip and inability of rubber cylinder to rebound effectively by using new soluble materials; (3) for the traditional throttle nozzle with fixed diameter, it is necessary to salvage the throttle when replacing it, which is time-consuming, tedious, costly and easy to lead to throttle failure. Under the premise of not changing normal operating environment, it is the future research direction to adjust the diameter of throttle nozzle effectively, conveniently and intelligently according to real-time downhole temperature and pressure conditions; (4) the large amount of sand produced from the wellbore is the main cause of failure of downhole throttle salvaging operation. The problems that throttle salvaging failure and erosion of throttle anti-sand screen tube are caused by wellbore sand production have been well researched in the innovation of throttle salvaging tools. It is necessary to further study the anti-sand screen tube, multistage anti-sand and anti-sand structure. It points out the direction of further research on downhole throttle.

The most remarkable variable cycle characteristic of the variable cycle engine (VCE) is that it keeps airflow almost constant during subsonic cruise throttling by modulating variable geometries, which can efficiently decrease spillage drag and increase installed thrust. One of the most critical challenges for the modulation lies in completely maintaining airflow, as well as avoiding specific fuel consumption (SFC) degradation during throttling. This has resulted in a need to investigate the modulation regulation of the adaptive cycle engine (ACE) which is a new concept for VCE and has greater potential for flexibly modulating airflow and pressure ratio. Thus, the aim of this paper is to study the variable geometries’ modulation schedule of ACE in maintaining airflow during throttling. A configuration of an ACE concept and its modeling study are first put forward. Then, the control schedule is researched via the combination of sensibility analysis and basic working principle instead of optimizing them directly. Results show that when the net thrust decreases from 100% to about 55% during subsonic cruise and to 32% during the supersonic cruise, the demand airflow of the engine is kept almost constant, which greatly improves the installed performance during throttling.

Despite limited genomic diversity, severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) has shown a wide range of clinical manifestations in different patient populations. The mechanisms behind these host differences are still unclear. Here, we examined host response gene expression across infection status, viral load, age, and sex among shotgun RNA sequencing profiles of nasopharyngeal (NP) swabs from 430 individuals with PCR-confirmed SARS-CoV-2 and 54 negative controls. SARS-CoV-2 induced a strong antiviral response with up-regulation of antiviral factors such as OAS1-3 and IFIT1-3 and T helper type 1 (Th1) chemokines CXCL9/10/11, as well as a reduction in transcription of ribosomal proteins. SARS-CoV-2 culture in human airway epithelial (HAE) cultures replicated the in vivo antiviral host response 7 days post infection, with no induction of interferon-stimulated genes after 3 days. Patient-matched longitudinal specimens (mean elapsed time = 6.3 days) demonstrated reduction in interferon-induced transcription, recovery of transcription of ribosomal proteins, and initiation of wound healing and humoral immune responses. Expression of interferon-responsive genes, including ACE2, increased as a function of viral load, while transcripts for B cell-specific proteins and neutrophil chemokines were elevated in patients with lower viral load. Older individuals had reduced expression of the Th1 chemokines CXCL9/10/11 and their cognate receptor CXCR3, as well as CD8A and granzyme B, suggesting deficiencies in trafficking and/or function of cytotoxic T cells and natural killer (NK) cells. Relative to females, males had reduced B cell-specific and NK cell-specific transcripts and an increase in inhibitors of nuclear factor kappa-B (NF-κB) signaling, possibly inappropriately throttling antiviral responses. Collectively, our data demonstrate that host responses to SARS-CoV-2 are dependent on viral load and infection time course, with observed differences due to age and sex that may contribute to disease severity.