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This paper is concerned with the problem of prescribed performance control (PPC) for a class of strict-feedback nonlinear systems, in which uncertain nonlinearity and uncertain disturbance exist in the considered nonlinear system at the same time, and the input control signal of the system is constrained by saturation nonlinearity. The adaptive neural network is used to approximate all unknown nonlinearity of the closed-loop system. And a new class of error transformation functions is proposed for the first time, which is superior to other similar documents in that the output error can always be constrained by the prescribed band only according to the properties of the designed error transformation function without any additional conditions. The simulation results finally verify the effectiveness of the proposed algorithm. [ABSTRACT FROM AUTHOR]

Cross-regional technology transfer is an important driving force for achieving the coordinated development of technology resources and breaking down China's provincial technical barriers. Due to the imbalance in China's technology development level, it is difficult to achieve comprehensive revitalization policies. Therefore, improving the efficiency of technology transfer is an effective way to solve this problem. This paper selects the relevant data of 31 provinces and regions in China in 2019 for analysis, uses factor analysis to measure the efficiency of technology transfer, and then proposes a technology transfer improvement path through QCA clear set configuration analysis. The study found that the development of technology transfer efficiency in 31 provinces and regions in China is extremely unbalanced. The improvement paths that effectively break this unbalanced development status can be summarized into 4 types, namely, the "intermediary-environment" leading path, weak "intermediary-R&D-environment" leading path, strong "intermediary-R&D-environment" leading path and "intermediary-economic" leading path. [ABSTRACT FROM AUTHOR]

The purpose of the present study was to characterize uncommon portosystemic collateral circulation in hepatic cirrhosis. Portosystemic uncommon collateral circulation (UCC) was detected, characterized and evaluated by a combination of spiral computed tomography angiography, three-dimensional imaging angiography and electronic gastroscopy in patients diagnosed with hepatic cirrhosis. In total, 118 cases with UCC were detected from a pool of 700 hepatic cirrhosis patients with portal hypertension. The incidence was 16.86% and included cases with splenic-renal, gastro-renal, paravertebral, retroperitoneal, gastric-splenic and cardio-phrenic angle vein shunts. The occurrence rate of UCC formation increased with the Child-Pugh grade. Compared with common collateral circulations, the incidence of severe esophageal or gastric fundus varicose veins, severe portal hypertensive gastropathy and the incidence of a large quantity of ascites was much lower in the patients with UCC (P<0.01), whereas the incidence of hepatic encephalopathy and chronic elevated blood ammonia levels was significantly higher (P<0.01). The incidence of uncommon portosystemic collateral circulation is extremely common in patients with liver cirrhosis and is associated with the Child-Pugh grades of hepatic function. UCC can aid in the relief of the complications derived from portal hypertension, but it may increase the incidence of hepatic encephalopathy and chronic elevated blood ammonia levels. [ABSTRACT FROM AUTHOR]