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Two-dimensional materials-based field-effect transistors (2DM-FETs) exhibit both ambipolar and unipolar transport types. To physically and compactly cover both cases, we put forward a quasi-Fermi-level phase space (QFLPS) approach to model the ambipolar effect in our previous work. This work aims to further improve the QFLPS model's numerical aspect so that the model can be implanted into the standard circuit simulator. We first rigorously derive the integral-free formula for the drain-source current to achieve this goal. It is more friendly to computation than the integral form. Besides, it explicitly gives the correlation terms between the electron and hole components. Secondly, to work out the boundary values required by the new expressions, we develop a fast evaluation algorithm for the surface electrostatic potential based on the zero-temperature limit property of the 2DM-FET system. By calibrating the model with the realistic device data of black phosphorus (BP) and monolayer molybdenum disulfide (ML-MoS2) FETs, the completed algorithm is tested against practical cases. The results show a typical superiority to the benchmark algorithm by two orders of magnitude in time consumption can be achieved while keeping a high accuracy with 7 to 9 significant digits., 17 pages, 9 figures

Two-dimensional material-based field effect transistors (2DM-FETs) are playing a revolutionary role in electronic devices. However, after years of development, no device model can match the Pao-Sah model for standard silicon-based transistors in terms of physical accuracy and computational efficiency to support large-scale integrated circuit design. One remaining critical obstacle is the contacts of 2DM-FETs. In order to self-consistently include the contact effect in the current model, it is necessary to perform self-consistent calculations, which is a fatal flaw for applications that prioritize efficiency. Here, we report that the Landauer-QFLPS model effectively overcomes the above contradiction, where QFLPS means quasi-Fermi-level phase space theory. By connecting the physical pictures of the contact and the intrinsic channel part, we have successfully derived a drain-source current formula including the contact effect. To verify the model, we prepared transistors based on two typical 2DMs, black phosphorus (BP) and molybdenum disulfide (MoS2), the former having ambipolar transport and the latter showing electron-dominant unipolar transport. The proposed new formula could describe both 2DM-FETs with Schottky or Ohmic contacts. Moreover, compared with traditional methods, the proposed model has the advantages of accuracy and efficiency, especially in describing non-monotonic drain conductance characteristics, because the contact effect is self-consistently and compactly packaged as an exponential term. More importantly, we also examined the model at the circuit level. Here, we fabricated a three-bit threshold inverter quantizer circuit based on ambipolar-BP process and experimentally demonstrated that the model can accurately predict the circuit performance. This industry-benign 2DM-FET model is supposed to be very useful for the development of 2DM-FET-based integrated circuits.

To improve the ecological environment quality of industrial cities and protect the health of residents, we determined the priority control factors of heavy metal(loid)s (HMs) pollution and risk in the resuspended street dust (RSD) of Shijiazhuang, an emblematic heavy-industrial city in North China, according to the probabilistic risk assessment method. The results showed that the HMs studied in Shijiazhuang RSD exhibited different pollution levels, that is, Hg showed moderate-to-severe pollution and above; Zn showed moderate-and-above pollution; Co, Cu and Pb showed non-pollution to moderate pollution; while As, Cr, Mn and Ni showed no pollution. The overall contamination of HMs in the RSD presented moderate-to-above contamination levels in >94% of samples. Mercury exhibited considerable-to-very-high ecological risk. The synthetic ecological risks of the HMs were considerable-to-above. The comprehensive pollution and synthetic ecological risk of HMs in Shijiazhuang RSD were mainly caused by Hg. The carcinogenic risk of HMs in RSD to local inhabitants and their non-carcinogenic risk to children should not be ignored. Coal-related industrial sources are a priority source to control. Hg and As are priority HMs to control. We suggest that local governments should strengthen the management of coal-related industrial sources and As and Hg emissions.

Bilateral basal ganglia hemorrhages are extremely rare and have very poor prognosis. We describe the case of a 52-year-old woman with a history of hypertension who experienced bilateral basal ganglia hemorrhages. We performed bilateral hematoma aspiration by minimally invasive surgery via frontal and temporal puncture points. We discuss the surgical procedure and review relevant literature pertaining to the underlying causes and complications of similar cases.

Treating an abdominal aortic aneurysm (AAA) with a stent graft (SG) and a multilayer stent (MS) is a key technology in isolating flow fields. Clinically, dual stents (an SG in the proximal and an MS in the distal of AAA) are used for treatment of AAA, but only a few studies have examined the relationship between SG coverage and treatment effects. Through numerical simulation of the hemodynamics after SG and MS implantation, the SG coverage and position were simulated at 0% (0 mm), 25% (13.75 mm), 50% (27.5 mm), and 75% (41.25 mm). With increasing SG coverage, the pressure on the aneurysm sac wall and the flow of branch vessels gradually decreased, and the lower wall shear stress (WSS) gradually increased. The changes in pressure, lower WSS, and the mass flow rate of the branch vessels did not change significantly. The coverage of the SG has a nonsignificant effect on hemodynamics in the treatment of AAA; the implantation position need not be very precise. This research can provide theoretic support for clinicians’ decision-making.

Dongyong Zhang,1 Jiefu Yu,1 Zhenze Wang,1 Yiwei Wang2 1Department of Neurosurgery, The First Affiliated Hospital of China Medical University, Shenyang City, People’s Republic of China; 2Department of Anatomy, Shenyang Medical College, Shenyang City, People’s Republic of ChinaCorrespondence: Dongyong ZhangDepartment of Neurosurgery, The First Affiliated Hospital of China Medical University, Nanjing Bei Street, Heping District, Shenyang City 110001, People’s Republic of ChinaTel +86 24 83283706Fax +86 24 83283133Email zhangdongyong@cmu.edu.cnAbstract: Bilateral basal ganglia hemorrhages are extremely rare and have very poor prognosis. We describe the case of a 52-year-old woman with a history of hypertension who experienced bilateral basal ganglia hemorrhages. We performed bilateral hematoma aspiration by minimally invasive surgery via frontal and temporal puncture points. We discuss the surgical procedure and review relevant literature pertaining to the underlying causes and complications of similar cases.Keywords: preexisting hypertension, intracranial hemorrhage, surgical procedure, hemorrhage aspiration, puncture points