This paper presents a control strategy to improve the low-voltage ride-through capability of a doubly fed induction generator (DFIG); since the stator of a DFIG is directly connected to a grid, this sort of machine is very sensitive to grid disturbance. Grid voltage sag causes overcurrents and overvoltages in rotor windings, which can damage the rotor-side converter (RSC). In order to protect the RSC, a classical solution based on installation of the so-called crowbar is adopted; however, as the DFIG absorbs reactive power from the grid, this type of solution deteriorates grid voltage sags and cannot meet the requirements of a new grid code. An improved control strategy which uses virtual resistance to limit rotor side overcurrents is proposed in this paper, which can make a crowbar inactive and supply reactive power to fulfill the latest grid code requirement during voltage sags. In order to validate the proposed strategy, simulations and experiments have been carried out, and the results demonstrate the effectiveness of the proposed strategy.

Chinese herbal medicine (CHM), as the largest application category of traditional Chinese medicine (TCM), is widely accepted among cancer patients in China. Herbal slice (HS) and Chinese patent drug (CPD) are commonly used CHM in China. This study aimed to investigate the utilization of CHM among clinicians and cancer patients in central China. Five hundred and twenty-five patients and 165 clinicians in 35 comprehensive hospitals in central China were asked to complete an anonymous questionnaire that was designed to evaluate the use of CHM. The results showed that 90.74% clinicians and 72.24% cancer patients used CHM during cancer treatment. The educational backgrounds of the clinicians and the age, education level, annual income, and cancer stage of the cancer patients were related to use of CHM. More than 90% clinicians and cancer patients had used CPD. Comparatively, the percentage of HS use was 10% lower than that of CPD use among clinicians and cancer patients. More clinicians preferred to use CHM after surgery than cancer patients did (20.41% vs. 5.37%). Enhancing physical fitness and improving performance status were regarded as the most potential effect of CHM on cancer treatment (85.71% among clinicians and 94.07% among cancer patients), in comparison with directly killing tumor cells (24.49% among clinicians and 31.36% among patients). As for refusal reasons, imprecise efficacy was the unanimous (100%) reason for clinicians' rejection of CHM, and 95.58% patients objected to using CHM also for this reason. Furthermore, the side effects of CHM were more concerned by clinicians than by patients (33.33% vs. 15.81%). In conclusion, our survey revealed that CHM was popularly accepted by clinicians and cancer patients in central China. The reasons of use and rejection of CHM were different between clinicians and cancer patients.

4072 Background: Tislelizumab, an anti-PD-1 monoclonal antibody, demonstrated clinical activity and was well tolerated in pts with previously treated advanced HCC in the Phase 2 RATIONALE-208 study (NCT03419897). At the time of this study, SOR and LEN were recommended first-line treatments for pts with advanced HCC and continue to have an important role in the first-line treatment of HCC despite the recent approval of new immuno-oncology-based combinations (atezolizumab and bevacizumab) in some regions. We report the clinical outcomes of pts with advanced HCC who were previously treated with SOR/LEN. Methods: Pts who had received ≥ 1 prior line of systemic therapy for advanced HCC received tislelizumab 200 mg intravenously once every three weeks. Objective response rate (ORR) by independent review committee (IRC) (ORRIRC), duration of response by IRC (DORIRC), progression-free survival by IRC (PFSIRC), overall survival (OS), and safety were evaluated in pts who had been previously treated with SOR/LEN. Results: As of February 2020, 249 pts were enrolled and 235 pts had received prior treatment with SOR/LEN, of whom 126 and 109 pts had received 1 or ≥ 2 prior lines of systemic therapy, respectively. At study entry, 211 (89.8%) pts had BCLC stage C and 187 (79.6%) pts had extrahepatic spread. Median follow-up duration for pts previously treated with SOR/LEN was 12.5 months and ORRIRC was 13.6% (95% CI: 9.5, 18.7), including 2 complete responses and 30 partial responses. Median DORIRC was not reached. Median PFSIRC and OS of pts previously treated with SOR/LEN was 2.7 months (95% CI: 1.6, 2.8) and 13.5 months (95% CI: 10.9, 15.8), respectively. Tislelizumab was generally well tolerated in pts previously treated with SOR/LEN (Table), and the most common treatment-emergent adverse events were increased aspartate aminotransferase (n=70; 28.1%) and alanine aminotransferase (n=52; 20.9%). Conclusions: Tislelizumab was investigated beyond the first-line setting, as effective second- and third-line treatment options are limited for pts with advanced HCC and there is an unmet medical need. This analysis indicates that tislelizumab is clinically active and well tolerated in pts with advanced HCC who have received prior systemic treatment with SOR/LEN. Clinical trial information: NCT03419897. [Table: see text]

Honeycomb structure coated with paraffin filled with composite of graphene and flaky carbonyl iron powder (FCIP) as lossy filler have been studied. The composite of graphene/FCIP with different weight ratio were synthesized via mechanical milling, the electromagnetic properties of the samples were measured by transmission/reflection method in the frequency range of 8-12 GHz. The microwave absorbing properties of the microwave absorbing honeycomb structure (MAHS) and microwave absorbing honeycomb sandwich structure (MAHSS) were studied based on the Finite Element Method with periodical boundary conditions. The matching layer on the top of the honeycomb sandwich structure can enhanced the microwave absorption properties. It was shown that a light weight and broadband MAHSS could be implemented with the use of the magnetic material and dielectric material.

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We propose a novel chirp compensation scheme for directly modulated threesection distributed Bragg reflector (3s-DBR) lasers in applications of the time-and wavelength-division multiplexed passive optical network systems. The frequency chirp of 3s-DBR lasers induced by direct modulation is investigated through extensive numerical simulations based on the time-domain travel-wave model. To overcome the signal distortions resulting from the frequency chirp due to direct modulation, we extend on our novel idea of frequency chirp compensation technology with inherent characteristics of DBR-type tunable lasers. Q factors and extinction ratio for different system transmission lengths are analyzed and compared. Large dispersion tolerance of the system is achieved by using the chirp compensation scheme.