Micro-rolling Forming of Light Extraction Structure on Substrate for LED Chip-on-Board Package

Xiaofang Huang,Dayong Yang,Zhenping Wan,Longsheng Lu 한국정밀공학회 2020 International Journal of Precision Engineering and Vol.21 No.9

The light extraction structure (LES) on substrate for chip-on-board (COB) packaging light-emitting diodes is an effective means to address the intrinsic problem—the total internal reflection occurred within a COB packaging device. This work develops a new manufacturing method—micro-rolling forming to machine inverted pyramid LESs with high efficiency and low cost. In this method, a roller with closely arrayed micro pyramid teeth is designed and rolled on a copper substrate. A finite element model is established to analyze the forming process of the inverted pyramids and the forming process can be divided into four stages: elastic stage, yielding stage, hardening stage, full plastic deformation stage. The stress and strain mainly concentrate on the contact zone with the micro tooth abdomen. In this contact zone, the stress plateaus in the full plastic deformation stage are high and long, which drives the inverted pyramid formation. The side length of the inverted pyramid increases, while the cone angle decreases with the rolling depth increasing. Whereas the side length and cone angle vary slightly with the rolling speed increasing. The better rolling depth and speed for LES forming are 0.3–0.4 mm and 10–20 mm/s, respectively.

Walking patterns of Trichogramma chilonis and Trichogrammatoidea bactrae upon vegetable leaf surfaces

Desen WANG,Xiaofang HE,Chengyin ZHAO,Yurong He,Lihua LU,Yongli LUO,Hualong QIU 한국곤충학회 2020 Entomological Research Vol.50 No.1

Trichogramma chilonis Ishii (Hymenoptera: Trichogrammatidae) and Trichogrammatoidea bactrae Nagaraja (Hymenoptera: Trichogrammatidae) are egg parasitoids of the diamondback moth, Plutella xylostella (L.) (Lepidoptera: Plutellidae). We observed and recorded the walking patterns of T. chilonis and T. bactrae females on leaves of Raphanus sativus L., Brassica juncea (L.) Czern. et Coss., Brassica campestris L. ssp. chinensis var. utilis Tsen et Lee, and Brassica oleracea L. Our analysis indicated that Trichogramma females spent more time and moved more slowly on R. sativus leaf surface, compared with the other vegetable leaf surfaces. In addition, Trichogramma females were more likely to walk in straight line on B. oleracea leaf surfaces than R. sativus, B. juncea, and B. campestris leaf surface. Compared to T. bactrae females, T. chilonis females spent significantly less time on the leaf surface, and the walking path of T. chilonis was less affected by leaf surface characters (e.g., trichomes, wrinkle, and waxes). During the period of residence on the leaf surface, parasitoid females spent more than 87.8% of their time moving. This study demonstrates that vegetable leaf surface can influence Trichogramma’s walking pattern while they are foraging for hosts.

Effects of Fengliao-Changweikang in Diarrheapredominant Irritable Bowel Syndrome Rats and Its Mechanism Involving Colonic Motility

( Mengdi Jia ),( Xiaofang Lu ),( Zhengfang Wang ),( Luqing Zhao ),( Shengsheng Zhang ) 대한소화기기능성질환·운동학회(구 대한소화관운동학회) 2018 Journal of Neurogastroenterology and Motility (JNM Vol.24 No.3

Background/Aims This study was designed to investigate the effect of Fengliao-Changweikang (FLCWK) in diarrhea-predominant irritable bowel syndrome (IBS-D) rats and explore its underlying mechanisms. Methods IBS-D model rats were induced by neonatal maternal separation (NMS) combined with restraint stress (RS). In in vivo experiments, the model rats were randomly divided into 5 groups: NMS + RS, FLCWK (low dose, middle dose, and high dose), and pinaverium bromide. The normal control (no handling) rats were classified as the NH group. The therapeutic effect of FLCWK was evaluated by fecal characteristics, electromyographic response and abdominal withdrawal reflex scores. In in vitro experiments, the model rats were randomly divided into 2 groups: NMS + RS, FLCWK (middle dose), and no handling rats were used as the NH group. The differences in basic tension and ACh-induced tension of isolated colonic longitudinal smooth muscle strips (CLSMs) among the 3 groups were observed. In addition, different inhibitors (nifedipine, TMB-8, L-NAME, methylene blue, and 4-AP) were pretreated to explore the underlying mechanisms. Results In in vivo experiments, fecal characteristics, electromyographic response, and abdominal withdrawal reflex scores significantly improved in the FLCWK group, compared with the NMS + RS group. In in vitro experiments, the basic tension and ACh-induced tension of CLSMs in IBS-D rats were significantly inhibited by FLCWK. After pre-treatment with different inhibitors, the ACh-induced tension of CLSMs in each group showed no significant difference. Conclusions FLCWK manifested curative effect in IBS-D rats by inhibiting colonic contraction. The underlying mechanisms may be related to regulatory pathway of nitric oxide/cGMP/Ca²⁺ and specific potassium channels. (J Neurogastroenterol Motil 2018;24:479-489)

Application and optimal design of the bionic guide vane to improve the safety serve performances of the reactor coolant pump

Liu Haoran,Wang Xiaofang,Lu Yeming,Yan Yongqi,Zhao Wei,Wu Xiaocui,Zhang Zhigang 한국원자력학회 2022 Nuclear Engineering and Technology Vol.54 No.7

As an important device in the nuclear island, the nuclear coolant pump can continuously provide power for medium circulation. The vane is one of the stationary parts in the nuclear coolant pump, which is installed between the impeller and the casing. The shape of the vane plays a significant role in the pump's overall performance and stability which are the important indicators during the safety serve process. Hence, the bionic concept is firstly applied into the design process of the vane to improve the performance of the nuclear coolant pump. Taking the scaled high-performance hydraulic model (on a scale of 1:2.5) of the coolant pump as the reference, a united bionic design approach is proposed for the unique structure of the guide vane of the nuclear coolant pump. Then, a new optimization design platform is established to output the optimal bionic vane. Finally, the comparative results and the corresponding mechanism are analyzed. The conclusions can be gotten as: (1) four parameters are introduced to configure the shape of the bionic blade, the significance of each parameter is herein demonstrated; (2) the optimal bionic vane is successfully obtained by the optimization design platform, the efficiency performance and the head performance of which can be improved by 1.6% and 1.27% respectively; (3) when compared to the original vane, the optimized bionic vane can improve the inner flow characteristics, namely, it can reduce the flow loss and decrease the pressure pulsation amplitude; (4) through the mechanism analysis, it can be found out that the bionic structure can induce the spanwise velocity and the vortices, which can reduce drag and suppress the boundary layer separation.

Transplantation of Wnt5a-modified NSCs promotes tissue repair and locomotor functional recovery after spinal cord injury

Li Xiang,Peng Zhiming,Long Lingli,Lu Xiaofang,Zhu Kai,Tuo Ying,Chen Ningning,Zhao Xiaoyang,Wang Le,Wan Yong 생화학분자생물학회 2020 Experimental and molecular medicine Vol.52 No.-

Traditional therapeutic strategies for spinal cord injury (SCI) are insufficient to repair locomotor function because of the failure of axonal reconnection and neuronal regeneration in the injured central nervous system (CNS). Neural stem cell (NSC) transplantation has been considered a potential strategy and is generally feasible for repairing the neural circuit after SCI; however, the most formidable problem is that the neuronal differentiation rate of NSCs is quite limited. Therefore, it is essential to induce the neuronal differentiation of NSCs and improve the differentiation rate of NSCs in spinal cord repair. Our results demonstrate that both Wnt5a and miRNA200b-3p could promote NSC differentiation into neurons and that Wnt5a upregulated miRNA200b-3p expression through MAPK/JNK signaling to promote NSC differentiation into neurons. Wnt5a could reduce RhoA expression by upregulating miRNA200b-3p expression to inhibit activation of the RhoA/Rock signaling pathway, which has been reported to suppress neuronal differentiation. Overexpression of RhoA abolished the neurogenic capacity of Wnt5a and miRNA200b-3p. In vivo, miRNA200b-3p was critical for Wnt5a-induced NSC differentiation into neurons to promote motor functional and histological recovery after SCI by suppressing RhoA/Rock signaling. These findings provide more insight into SCI and help with the identification of novel treatment strategies.