Auto-Detection of Programming Code Vulnerabilities With Natural Language Processing

Security vulnerabilities in source code are traditionally detected manually by software developers because there are no effective auto-detection tools. Current vulnerability detection tools require great human effort, and the results have flaws in many ways. However, deep learning models could be a solution to this problem for the following reasons: 1. Deep learning models are relatively accurate for text classification and text summarization for source code. 2. After being deployed on the cloud servers, the efficiency of deep learning based auto-detection could be much higher than human effort. Therefore, we developed two Natural Language Processing(NLP) models: the first one is a text-classification model that takes source code as input and outputs the classification of the security vulnerability of the input. The second one is a text-to-text model that takes source code as input and outputs a completely machine-generated summary about the security vulnerability of the input. Our evaluation shows that both models get impressive results

Reprocessable Thermoset Soft Actuators.

Widely used traditional thermosets are good candidates for construction of 3D soft actuators because of their excellent stability; however, it is generally acknowledged that they cannot be reprocessed. The time-temperature equivalence principle enables reprocessing of traditional liquid crystalline epoxy thermosets (LCETs) into 3D soft actuators. Even though the transesterification reaction of LCETs is extremely slow, it is fast enough to induce a topology rearrangement and subsequent reprocessing when prolonging the transesterification time according to aforementioned principle. Therefore, LCETs can be aligned by a simple procedure. The alignment is quite stable at high temperature and remains after more than 1000 heating-cooling actuation cycles. The resulting 3D soft actuators are remouldable, reprogrammable, reconfigurable, weldable, self-healable, recyclable, and stable, which is impossible for any traditional thermosets and is therefore a compelling advance in terms of the applications open to 3D soft actuators

Y-Chromosome Evidence for Common Ancestry of Three Chinese Populations with a High Risk of Esophageal Cancer

High rates of esophageal cancer (EC) are found in people of the Henan Taihang Mountain, Fujian Minnan, and Chaoshan regions of China. Historical records describe great waves of populations migrating from north-central China (the Henan and Shanxi Hans) through coastal Fujian Province to the Chaoshan plain. Although these regions are geographically distant, we hypothesized that EC high-risk populations in these three areas could share a common ancestry. Accordingly, we used 16 East Asian-specific Y-chromosome biallelic markers (single nucleotide polymorphisms; Y-SNPs) and six Y-chromosome short tandem repeat (Y-STR) loci to infer the origin of the EC high-risk Chaoshan population (CSP) and the genetic relationship between the CSP and the EC high-risk Henan Taihang Mountain population (HTMP) and Fujian population (FJP). The predominant haplogroups in these three populations are O3*, O3e*, and O3e1, with no significant difference between the populations in the frequency of these genotypes. Frequency distribution and principal component analysis revealed that the CSP is closely related to the HTMP and FJP, even though the former is geographically nearer to other populations (Guangfu and Hakka clans). The FJP is between the CSP and HTMP in the principal component plot. The CSP, FJP and HTMP are more closely related to Chinese Hans than to minorities, except Manchu Chinese, and are descendants of Sino-Tibetans, not Baiyues. Correlation analysis, hierarchical clustering analysis, and phylogenetic analysis (neighbor-joining tree) all support close genetic relatedness among the CSP, FJP and HTMP. The network for haplogroup O3 (including O3*, O3e* and O3e1) showed that the HTMP have highest STR haplotype diversity, suggesting that the HTMP may be a progenitor population for the CSP and FJP. These findings support the potentially important role of shared ancestry in understanding more about the genetic susceptibility in EC etiology in high-risk populations and have implications for determining the molecular basis of this disease

Determination and contents analysis of negative ions in vegetable simultaneous by ion chromatography

A method of high-speed to determine some negative ions and their contents in vegetable by ion chromatography is proposed in this paper, which was based on the research of 2 negative ions in 16 kinds of vegetable from Hainan Danzhou market. This method is of easy usage, high-speed, good reappearance and the result is satisfactory. The correlation coefficients(r) of NO2- and NO3- were 0.9998 and 0.9991. Relative standard deviations (RSD) were 0.65% and 0.04%, respectively.By the determination of NO2-, and NO3- in vegetable, the results indicated that the contents of negative ions in different vegetables (the organ for eating) are fairly different

Porous Media Modeling of Two-Phase Microchannel Cooling of Electronic Chips With Nonuniform Power Distribution

Compared to single-phase heat transfer, two-phase microchannel heat sinks utilize latent heat to reduce the needed flow rate and to maintain a rather uniform temperature close to the boiling temperature. The challenge in the application of cooling for electronic chips is the necessity of modeling a large number of microchannels using large number of meshes and extensive computation time. In the present study, a modified porous media method modeling of two-phase flow in microchannels is performed. Compared with conjugate method, which considers individual channels and walls, it saves computation effort and provides a more convenient means to perform optimization of channel geometry. The porous media simulation is applied to a real chip. The channels of high heat load will have higher qualities, larger flow resistances, and lower flow rates. At a constant available pressure drop over the channels, the low heat load channels show much higher mass flow rates than needed. To avoid this flow maldistribution, the channel widths on a chip are adjusted to ensure that the exit qualities and mass flow rate of channels are more uniform. As a result, the total flow rate on the chip is drastically reduced, and the temperature gradient is also minimized. However, it only gives a relatively small reduction on the maximum surface temperature of chip

A magnetic solder for assembling bulk covalent adaptable network blocks.

Covalent adaptable networks (CANs) represent a novel covalently cross-linked polymer that is capable of being reprocessed and recycled relying on reversible covalent bond structures and present exceptional opportunities in a wide range of prospective applications. However, it is genuinely difficult to fabricate bulk CAN blocks with solid-core geometries that possess complex shapes or multiple materials, which are crucial in cutting-edge fields such as soft robotics, flexible electronic devices and biomedical engineering. Here we report a welding technique to strategically construct complex and heterogeneous 3D CAN structures by utilizing a solder doped with magnetic nanoparticles. The solder is able to induce a bond exchange reaction at the interface between the to-be-welded pieces. Using this method, not only CAN bulks with the same materials can be welded to form complex geometries, distinctive bulks with different physical properties and chemical compositions can also be connected to fabricate multimaterial devices. Besides, this method can be used to repair damaged CAN materials and efficiently recycle scrap CAN materials, which can effectively save resources and protect the environment. The universality and robustness of this strategy is expected to promote CAN application in broader functional polymer fields

A magnetic solder for assembling bulk covalent adaptable network blocks.

Covalent adaptable networks (CANs) represent a novel covalently cross-linked polymer that is capable of being reprocessed and recycled relying on reversible covalent bond structures and present exceptional opportunities in a wide range of prospective applications. However, it is genuinely difficult to fabricate bulk CAN blocks with solid-core geometries that possess complex shapes or multiple materials, which are crucial in cutting-edge fields such as soft robotics, flexible electronic devices and biomedical engineering. Here we report a welding technique to strategically construct complex and heterogeneous 3D CAN structures by utilizing a solder doped with magnetic nanoparticles. The solder is able to induce a bond exchange reaction at the interface between the to-be-welded pieces. Using this method, not only CAN bulks with the same materials can be welded to form complex geometries, distinctive bulks with different physical properties and chemical compositions can also be connected to fabricate multimaterial devices. Besides, this method can be used to repair damaged CAN materials and efficiently recycle scrap CAN materials, which can effectively save resources and protect the environment. The universality and robustness of this strategy is expected to promote CAN application in broader functional polymer fields

Porous Media Modeling of Two-Phase Microchannel Cooling of Electronic Chips With Nonuniform Power Distribution

<p>Compared to single-phase heat transfer, two-phase microchannel heat sinks utilize latent heat to reduce the needed flow rate and to maintain a rather uniform temperature close to the boiling temperature. The challenge in the application of cooling for electronic chips is the necessity of modeling a large number of microchannels using large number of meshes and extensive computation time. In the present study, a modified porous media method modeling of two-phase flow in microchannels is performed. Compared with conjugate method, which considers individual channels and walls, it saves computation effort and provides a more convenient means to perform optimization of channel geometry. The porous media simulation is applied to a real chip. The channels of high heat load will have higher qualities, larger flow resistances, and lower flow rates. At a constant available pressure drop over the channels, the low heat load channels show much higher mass flow rates than needed. To avoid this flow maldistribution, the channel widths on a chip are adjusted to ensure that the exit qualities and mass flow rate of channels are more uniform. As a result, the total flow rate on the chip is drastically reduced, and the temperature gradient is also minimized. However, it only gives a relatively small reduction on the maximum surface temperature of chip.</p