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How do i use lodash with Ionic2?

Before proceeding, let's briefly review the fundamental concepts of Lodash and Ionic 2.Lodash is a JavaScript library offering numerous utility functions for handling arrays, objects, and other data types. Its functions are optimized to enhance the performance and efficiency of your code.Ionic 2 is an open-source frontend framework for developing cross-platform mobile applications. Built on Angular, it provides a rich set of components and tools to enable developers to build applications quickly.How to Integrate and Use Lodash in an Ionic 2 ProjectStep 1: Installing LodashThe first step to using Lodash in an Ionic 2 project is installing the Lodash library. You can install it via npm (Node Package Manager):This command downloads the Lodash library, adds it to your project's directory, and updates the file to include Lodash as a dependency.Step 2: Importing Lodash into an Ionic 2 ProjectAfter installation, you can import Lodash into any component or service of your Ionic project. Begin by importing it at the top of the relevant file:Step 3: Using Lodash's FeaturesOnce imported, you can leverage Lodash's functions wherever needed in your project. For example, use to filter arrays or to locate elements within an array.Consider this scenario: you have an array of user objects with and properties, and you need to find all users older than 30:SummaryBy following these steps, you can seamlessly integrate Lodash into your Ionic 2 project. Lodash's extensive utility functions significantly improve data processing efficiency and code readability. Using such libraries allows you to focus on implementing business logic rather than spending excessive time on low-level data operations.
答案1·2026年3月19日 23:40

How to use Lodash Debounce on resize

In frontend development, adjusting window size is a common requirement, but if not handled properly, it can easily cause performance issues. Frequently triggered resize events can cause noticeable lag on the page, affecting user experience. At this point, using Lodash's debounce function can effectively address this issue. The debounce function limits the frequency of function execution, ensuring that high-frequency events do not cause the function to be called repeatedly.Specific Implementation StepsInclude the Lodash LibraryEnsure that the Lodash library has been included in your project. If not already included, it can be added via CDN or npm/yarn:Define the Resize Handling FunctionThis function contains the logic to execute when the window size changes. For example, you may need to recalculate the layout or size of certain elements based on the new window dimensions.**Wrap the Handler with **Wrap your event handler function with Lodash's debounce method. Here, you can specify a delay time (e.g., 200 milliseconds), during which even if the event is triggered again, the handler will not execute.Bind the Debounced Function to the Resize EventFinally, bind the debounced function to the resize event instead of the original event handler.Example Application and EffectsThrough the above steps, we create an event handler that does not trigger frequently when the window size changes. This means that regardless of how quickly or frequently the user adjusts the browser window size, the handleResize function is executed no more than once every 200 milliseconds.This approach significantly reduces computational load and potential re-renders, thereby improving application performance and responsiveness, and enhancing user experience.
答案1·2026年3月19日 23:40

How can you assess the quality of a text classification model?

评估文本分类模型的质量,我们通常会依据以下几个标准:1. 准确率 (Accuracy)准确率是最直观的评估标准,它计算了模型正确分类的样本数占总样本数的比例。公式为:[ \text{准确率} = \frac{\text{正确预测的数量}}{\text{总样本数量}} ]例如,如果一个模型在100个文本中有90个预测正确,那么准确率就是90%。2. 精确度 (Precision) 和 召回率 (Recall)在文本分类中,我们经常关注特定类别的预测质量。精确度是指在所有预测为某个类别的文本中,实际属于该类别的比例。召回率是指在所有实际为某个类别的文本中,被正确预测为该类别的比例。公式为:[ \text{精确度} = \frac{\text{真正例 (TP)}}{\text{真正例 (TP) + 假正例 (FP)}} ][ \text{召回率} = \frac{\text{真正例 (TP)}}{\text{真正例 (TP) + 假负例 (FN)}} ]例如,在预测垃圾邮件时,高精确度意味着标记为垃圾邮件的大部分确实是垃圾邮件,而高召回率则意味着我们成功捕捉了大部分垃圾邮件。3. F1 分数F1 分数是精确度和召回率的调和平均,是一个综合考量两者的指标,特别适用于类别不平衡的情况。公式为:[ F1 = 2 \times \frac{\text{精确度} \times \text{召回率}}{\text{精确度} + \text{召回率}} ]这个指标在评估那些对精确度和召回率都很敏感的任务时特别有用。4. 混淆矩阵 (Confusion Matrix)混淆矩阵是一个非常直观的工具,它展示了模型在每个类别上的表现,包括真正例、假正例、真负例和假负例。通过混淆矩阵,我们可以详细了解模型在不同类别上的错误类型。5. ROC 曲线和 AUC 评分ROC 曲线是接收者操作特征曲线(Receiver Operating Characteristic curve)的缩写,它展示了在不同阈值设置下,模型的真正例率和假正例率。AUC(Area Under the Curve)评分则是ROC曲线下的面积,提供了一个量化模型整体性能的方式。AUC值越高,模型的性能越好。例子:假设我们正在评估一个用于情感分析的模型,该模型需要区分正面评价和负面评价。我们可以通过计算准确率、精确度、召回率和F1分数来评估模型在两个类别上的表现。如果模型在正面评价上的精确度很高,但召回率较低,则可能意味着许多正面评论没有被正确识别。通过调整模型或重新训练,我们可以试图改善这些指标。总结:综合使用这些指标,我们不仅能够评估模型的整体性能,还能深入了解模型在特定任务和特定类别上的表现。这有助于我们进行针对性的优化,从而开发出更精确、更可靠的文本分类系统。
答案1·2026年3月19日 23:40

Which classifier to choose in NLTK

当选择NLTK(Natural Language Toolkit)中的分类器时,需要考虑几个关键因素,包括项目的特定需求、数据的特性以及预期的准确性和性能。以下是几个常用的分类器及其适用情景的简要介绍:朴素贝叶斯分类器(Naive Bayes Classifier):适用情景: 适合于文本分类任务,例如垃圾邮件检测和情感分析。它是基于贝叶斯定理的,假设特征之间相互独立。优点: 简单且易于实现,计算成本低。缺点: 假设特征独立,这在现实世界中往往不是完全成立的。例子: 在电影评论情感分析中,朴素贝叶斯可以通过训练集中单词的出现频率来预测评论是正面还是负面。决策树分类器(Decision Tree Classifier):适用情景: 当你需要一个模型能够输出易于理解的决策规则时,决策树是一个很好的选择。适用于客户分级、诊断系统等。优点: 易于理解和解释,可以可视化决策过程。缺点: 容易过拟合,对于有很多类的数据集可能不是最佳选择。例子: 在金融行业中,决策树可以帮助确定是否批准贷款申请,根据申请人的年龄、收入、信用历史等因素。支持向量机(SVM):适用情景: 对于文本和图像分类问题非常有效,特别是在有明显的边界分隔类别时。优点: 在高维空间中效果好,适用于复杂域的分类问题,如手写识别或人脸识别。缺点: 对大规模数据训练较慢,对参数和核函数的选择敏感。例子: 在生物信息学中,SVM可以用来分类蛋白质结构。最大熵分类器(Maxent Classifier)/逻辑回归:适用情景: 当类别输出是概率时,最大熵分类器是合适的选择,适用于信用评分、疾病预测等。优点: 不假设特征独立,输出结果有概率解释。缺点: 需要较多的训练时间和数据。例子: 在市场营销中,最大熵模型可以用来预测顾客是否会购买某个产品,基于顾客的购买历史和个人资料。综合以上信息,选择最合适的分类器首先需要评估你的具体需求,包括你的数据类型、期望的模型性能以及是否需要模型的解释能力。对不同数据集和问题尝试多种模型,并使用交叉验证等技术来比较它们的性能,通常是一个好的实践。在选择过程中,也可以结合实际业务需求和技术资源进行权衡。
答案1·2026年3月19日 23:40

How to find the closest word to a vector using BERT

回答:要使用BERT模型来找到与给定向量最接近的单词,我们可以通过以下步骤来实现:加载BERT模型和词汇表:首先需要加载预训练的BERT模型及其对应的词汇表。这可以通过使用像Hugging Face的Transformers库来实现,例如:将单词转换为向量:使用BERT模型,我们可以将词汇表中的每个单词转换为一个向量。具体操作是将每个单词作为输入,通过BERT模型得到的输出中提取单词对应的向量。可以选择输出的最后一层或其他层的输出作为单词的向量表示。计算相似度:现在我们有了目标向量和词汇表中每个单词的向量表示,接下来需要计算这些向量与目标向量之间的距离。常见的距离计算方法包括余弦相似度和欧氏距离。例如,使用余弦相似度:找到最接近的单词:根据计算得到的相似度,我们可以找出与目标向量最接近的单词。可以通过相似度得分最高的单词来确定:例子:假设我们想找到与单词“apple”的向量最接近的单词。首先,我们需要获取“apple”的向量表示,然后计算它与词汇表中其他单词向量的相似度,最后找出最接近的单词。这种方法在自然语言处理中非常有用,特别是在进行词义相似度分析、文本聚类、信息检索等任务时。利用BERT的深层语义理解能力,能有效地捕捉到词汇之间的细微关联,从而提高任务的准确性和效率。
答案1·2026年3月19日 23:40

What is the difference between syntax and semantics in NLP?

In Natural Language Processing (NLP), syntax and semantics are two fundamental and important concepts that deal with the form and meaning of language, respectively.SyntaxSyntax refers to the set of rules governing the structure and form of sentences in a language. It is concerned solely with structural aspects, not the meaning, and focuses on how words are combined to form valid phrases and sentences. These rules encompass word order, sentence structure, punctuation usage, and other elements.For example, consider the English sentence: "The cat sat on the mat." This sentence adheres to English syntax rules as it correctly arranges nouns, verbs, and prepositions to create a coherent sentence structure.SemanticsSemantics is the study of the meaning of sentences or phrases. It involves understanding the specific meanings conveyed by words, phrases, and sentences, as well as how they communicate information in different contexts.Using the same example: "The cat sat on the mat." semantic analysis would involve interpreting the meanings of the words "cat," "sat," and "mat," as well as the overall information conveyed by the sentence, namely that a cat is sitting on a mat.Differences and InterdependenceAlthough syntax and semantics are distinct research areas, they are interdependent when processing natural language. A sentence may be grammatically correct but semantically nonsensical. For instance, "Colorless green ideas sleep furiously." is grammatically correct but semantically nonsensical, as the concept it describes does not exist in the real world.In NLP applications, understanding and implementing robust syntactic and semantic analysis are crucial, as they can enhance various applications such as machine translation, sentiment analysis, and question-answering systems.In summary, syntax is concerned with the structural aspects of sentences, while semantics deals with the content and meaning. Effective natural language processing systems must integrate both aspects to accurately understand and generate human language.
答案1·2026年3月19日 23:40

How can a sentence or a document be converted to a vector?

In the field of Natural Language Processing (NLP), converting sentences or documents into vectors is a fundamental and critical task that enables computers to understand and process textual data. Currently, multiple methods exist for this conversion, broadly categorized as follows:1. Bag of Words (BoW) MethodsBag of Words Model is a simple and effective text representation technique. It transforms text into a long vector where each dimension corresponds to a word in the vocabulary, and the value at each dimension indicates the frequency of that word in the text.Example:Suppose we have a vocabulary {"我":0, "喜欢":1, "你":2}; the sentence "我 喜欢 你" can be converted into the vector [1, 1, 1].2. TF-IDF MethodTF-IDF (Term Frequency-Inverse Document Frequency) is a widely used weighting approach in information retrieval and text mining. It enhances the importance of words that frequently appear in the current document but are uncommon across the corpus.Example:Continuing with the previous example, if the word "喜欢" is relatively rare in the entire corpus, its TF-IDF value would be higher, and the vector might appear as [0.1, 0.5, 0.1].3. Word Embedding MethodsWord embeddings represent words as dense vectors through training. Common models include Word2Vec, GloVe, and FastText.Example:In Word2Vec, each word is mapped to a predefined-size continuous vector space; for instance, "喜欢" might be represented as [0.2, -0.1, 0.9]. Converting a sentence into a vector typically involves averaging or weighted averaging the vectors of all words.4. Using Pre-trained Language ModelsWith advances in deep learning, methods leveraging pre-trained language models have gained significant popularity, such as BERT, GPT, and ELMo. These models, pre-trained on large-scale text corpora, better capture the deep semantics of language.Example:Using BERT, a sentence is first tokenized, then each token is converted into a word vector, processed through the model's multi-layer neural network, and finally outputs a new vector representation for each token. The sentence representation is obtained by aggregating all word vectors (e.g., via averaging).SummaryEach method has distinct advantages and limitations, and the choice depends on specific task requirements, text characteristics, and computational resources. For example, tasks requiring high semantic understanding may prefer pre-trained language models, while simple text classification tasks may suffice with TF-IDF or Bag of Words models. Through experimentation and evaluation, the most suitable method for a given application can be identified.
答案1·2026年3月19日 23:40

How to Extract the relationship between entities in Stanford CoreNLP

In Stanford CoreNLP, extracting relationships between entities involves the following steps:1. Environment Setup and ConfigurationFirst, ensure that the Java environment is installed and the Stanford CoreNLP library is properly configured. Download the latest library files, including all necessary models, from the official website.2. Loading Required ModelsTo extract entity relationships, at least the following modules must be loaded:Tokenizer: to split text into words.POS Tagger: to tag the part of speech for each word.NER: to identify entities in the text, such as names and locations.Dependency Parser: to analyze dependencies between words in a sentence.Relation Extractor: to extract relationships between entities based on identified entities and dependency relations.3. Initializing the PipelineUse the class to create a processing pipeline and load the above models. Example:4. Processing Text and Extracting RelationshipsInput the text to be analyzed into the pipeline and use the relation extractor to obtain relationships between entities. Example code:5. Analyzing and Using Extracted RelationshipsThe extracted relationships can be used for various applications, such as information retrieval, question answering systems, and knowledge graph construction. Each relationship consists of a subject, relation, and object, which can be further analyzed to understand semantic associations in the text.Example Application ScenarioSuppose we want to extract relationships between countries and their capitals from news articles. We can use the above method to identify mentioned countries and cities, then analyze and confirm which are capital-country relationships.Through this structured information extraction, we can effectively extract valuable information from large volumes of text, supporting complex semantic search and knowledge discovery.
答案1·2026年3月19日 23:40

How do I calculate similarity between two words to detect if they are duplicates?

When determining if two words are duplicates based on their similarity, several methods can be considered:1. Levenshtein DistanceLevenshtein distance measures the minimum number of single-character edits (insertions, deletions, or substitutions) required to transform one word into another. A smaller Levenshtein distance indicates higher similarity between the words.Example:The Levenshtein distance between "kitten" and "sitting" is 3 (k→s, e→i, insert 'g').2. Cosine SimilarityThis is typically used for comparing the similarity of text strings but can also be applied at the word level. Represent each word as a vector of character frequencies, then compute the cosine similarity between these vectors.Example:Treating "cat" and "bat" as vectors where each element represents the frequency of letters in the word. "cat" and "bat" differ only in the first character, but share identical character frequencies in the remaining positions, resulting in a high cosine similarity score.3. Jaccard SimilarityThe Jaccard similarity index quantifies similarity between sets by computing the ratio of the size of the intersection to the size of the union of the two sets.Example:The letter sets for "apple" and "appel" are both {a, p, l, e}, so their Jaccard similarity is 1 (indicating perfect similarity).4. N-gram SimilarityAn N-gram is a sequence of N consecutive characters in text. Assess similarity by comparing the overlap of N-grams between two words.Example:Using bigrams (N=2) to compare "brick" and "trick", the common bigrams are "ri" and "ck", making the words similar at the bigram level.5. Machine Learning-Based MethodsUse word embedding techniques (e.g., Word2Vec or GloVe), which capture semantic information and represent words as points in a vector space. Evaluate similarity by computing the distance between these vectors.Example:In a word embedding model, "car" and "automobile" may be very close in the vector space despite differing in spelling, due to their similar semantics.SummaryThe choice of method depends on the specific application. For semantic similarity, prioritize word embedding methods. For form-based similarity, edit distance or N-gram methods may be more suitable. Each technique has advantages and limitations, and appropriate selection enhances accuracy in detecting word duplicates.
答案1·2026年3月19日 23:40

How do you deal with the curse of dimensionality in NLP?

Facing the curse of dimensionality in Natural Language Processing (NLP), I typically employ several strategies to address it:1. Feature SelectionSelecting features most relevant to the task is crucial. This not only reduces data dimensionality but also enhances model generalization. For instance, in text classification tasks, we can evaluate and select the most informative words using methods such as TF-IDF, information gain, and mutual information.2. Feature ExtractionFeature extraction is another effective method for reducing dimensionality by projecting high-dimensional data into a lower-dimensional space to retain the most critical information. Common approaches include Principal Component Analysis (PCA), Linear Discriminant Analysis (LDA), and nonlinear dimensionality reduction via autoencoders.For example, in a text sentiment analysis project, I used PCA to reduce feature dimensionality, successfully improving both model speed and classification accuracy.3. Adopting Sparse RepresentationsIn NLP, word vectors are often high-dimensional and sparse. Utilizing sparse representations effectively reduces irrelevant and redundant dimensions. For instance, applying L1 regularization (Lasso) drives certain coefficients toward zero, achieving feature sparsity.4. Using Advanced Model StructuresModels such as Convolutional Neural Networks (CNN) and Recurrent Neural Networks (RNN) in deep learning are inherently suited for handling high-dimensional data. Furthermore, Transformer models effectively address long-range dependency issues through self-attention mechanisms while reducing computational complexity.5. Employing Embedding TechniquesIn NLP, word embeddings (such as Word2Vec, GloVe) are common techniques that convert high-dimensional one-hot encoded vocabulary into low-dimensional, continuous vectors with semantic information. This not only reduces dimensionality but also captures relationships between words.Practical CaseIn one of my text classification projects, I used word embeddings and LSTM networks to handle high-dimensional text data. By leveraging pre-trained GloVe vectors, I mapped each word to a low-dimensional space and utilized LSTM to capture long-term dependencies. This approach significantly enhanced the model's ability to handle high-dimensional data while optimizing classification accuracy.Overall, handling the curse of dimensionality requires selecting appropriate strategies based on specific problems and combining multiple techniques to achieve both dimensionality reduction and improved model performance.
答案1·2026年3月19日 23:40

How to extract phrases from corpus using gensim

When discussing how to use Gensim to extract phrases from a corpus, we can leverage the module of Gensim. This tool enables us to automatically detect common phrases (also known as 'collocations'), such as 'newyork' or 'financialcrisis', using statistical methods. I will detail the steps below.1. Prepare DataFirst, we prepare the text data. Suppose we have a list of documents, where each document is a list of words. For example:2. Train the ModelNext, we use these documents to train a model. This model identifies phrases in the documents that are combinations of multiple words, with their frequency in the corpus exceeding the specified threshold.Here, and are key parameters controlling the minimum occurrence count of a phrase across the corpus and the score threshold for phrases. is an optimized implementation of , enhancing efficiency during application.3. Apply the ModelOnce the phrase model is trained, we can apply it to new documents to combine common phrases into single tokens.The output will be:This demonstrates that 'new york' is correctly identified as a phrase and merged into a single token.4. Practical ExampleSuppose we have a news corpus focused on major U.S. cities, and we aim to identify frequently occurring city names (e.g., 'new york'). By following these steps, we can effectively identify and tag such phrases, which is highly beneficial for subsequent text analysis and information extraction.SummaryBy following these steps, we can effectively use Gensim's model to extract phrases from large volumes of text. This method not only improves text processing efficiency but also helps us more accurately understand and process data in tasks such as text analysis, information retrieval, or natural language processing.
答案1·2026年3月19日 23:40

In Natural language processing , what is the purpose of chunking?

In Natural Language Processing (NLP), chunking is a crucial process whose primary purpose is to combine individual words into larger units, such as phrases or noun phrases, which typically convey richer semantic information than single words. Chunking typically extracts grammatical constituents like noun phrases and verb phrases, aiding in sentence structure comprehension and thereby enhancing the efficiency and accuracy of information extraction and text understanding.Enhancing Semantic Understanding: By grouping words into phrases, it better captures sentence semantics. For example, the phrase 'New York City Center' contains significantly more information than the individual words 'New York' and 'City Center'.Information Extraction: In many NLP applications, such as Named Entity Recognition (NER) or relation extraction, chunking helps identify and extract key information from text. For instance, when processing medical records, recognizing 'Acute Myocardial Infarction' as a single unit greatly facilitates subsequent data analysis and patient management.Simplifying Syntactic Structure: Chunking simplifies complex sentence structures, making components more explicit and enabling efficient subsequent syntactic or semantic analysis.Improving Processing Efficiency: Pre-combining words into phrases reduces the number of units processed in later stages, thereby optimizing overall efficiency.Assisting Machine Translation: Proper chunking improves translation quality in machine translation, as many languages rely on phrases rather than individual words for expression patterns.For example, in the sentence 'Bob went to the new coffee shop', correct chunking should be ['Bob'] [went] [to] ['the new coffee shop']. Here, 'the new coffee shop' is identified as a noun phrase, which is critical for subsequent semantic understanding and information extraction—such as when extracting the visit location.
答案1·2026年3月19日 23:40

What are the main components of the spaCy NLP library?

Language Models: SpaCy provides multiple pre-trained language models supporting various languages (e.g., English, Chinese, German). These models facilitate various NLP tasks such as tokenization, part-of-speech tagging, and named entity recognition. Users can download appropriate models based on their needs.Pipelines: SpaCy's processing workflow is managed through pipelines, which consist of a sequence of processing components (e.g., tokenizers, parsers, and entity recognizers) executed in a specific order. This ensures SpaCy is both efficient and flexible when handling text.Tokenizer: Tokenization is a fundamental step in NLP. SpaCy offers an efficient tokenizer to split text into basic units like words and punctuation, and it also handles text preprocessing tasks such as normalization.Part-of-Speech Tagger: Part-of-speech tagging involves labeling words with their grammatical categories (e.g., nouns, verbs, adjectives). SpaCy uses pre-trained models for this task, which is foundational for subsequent tasks like syntactic parsing.Dependency Parser: Dependency parsing analyzes relationships between words. SpaCy's parser constructs dependency trees between words, which is highly useful for understanding sentence structure.Named Entity Recognizer (NER): NER identifies entities with specific meanings in text (e.g., names, locations, organizations). SpaCy's NER component recognizes multiple entity types and labels them accordingly.Text Categorizer: SpaCy provides components for text classification, such as sentiment analysis and topic labeling. These can be applied to various use cases, including automatically tagging customer feedback and content recommendation.Vectors & Similarity: SpaCy supports calculating text similarity using word vectors, achieved through pre-trained word vectors trained on large text datasets. This is useful for tasks like text similarity analysis and information retrieval.Through these components, SpaCy offers comprehensive support ranging from basic text processing to complex NLP applications. For instance, in a real-world project, I utilized SpaCy's dependency parsing and named entity recognition capabilities to automatically extract information about key events and related entities from large volumes of news articles, significantly improving the efficiency and accuracy of information extraction.
答案1·2026年3月19日 23:40

What is the importance of natural language processing?

Natural Language Processing (NLP) is a significant branch of artificial intelligence, encompassing technologies that enable computers to understand, interpret, and generate human language. NLP's importance is evident across multiple dimensions:Enhancing the Naturalness and Efficiency of Human-Machine Interaction: As technology advances, users expect interactions with machines to be as natural and efficient as conversations with humans. For instance, voice assistants like Siri and Alexa facilitate voice control and feedback, all underpinned by NLP technology.Data Processing Capabilities: In the data-driven era, vast amounts of unstructured data (such as text) require processing and analysis. NLP techniques can extract valuable insights from text, enabling sentiment analysis, topic classification, and other tasks to support decision-making. For example, companies can analyze customer online reviews to enhance products or services.Overcoming Language Barriers: NLP helps break down language barriers, allowing people from different linguistic backgrounds to communicate and collaborate effectively. Tools like Google Translate leverage NLP to provide real-time translation services, significantly promoting global communication.Educational Applications: In education, NLP can develop personalized learning systems that tailor instruction and feedback based on students' progress. Additionally, it assists language learning through intelligent applications that help users acquire new languages.Supporting Decision-Making and Risk Management: In sectors like finance and healthcare, NLP aids professionals by analyzing specialized documents (e.g., research reports, clinical records) to make more accurate decisions and identify potential risks and opportunities.For instance, in my previous project experience, I developed a customer service chatbot. By utilizing NLP technology, the chatbot understands user queries and provides relevant responses, significantly boosting customer service efficiency and satisfaction. Moreover, the system continuously learns from user interactions to refine its response model, making engagements more human-like and precise.In conclusion, natural language processing not only enables machines to better comprehend humans but also substantially enhances information processing efficiency and quality, driving revolutionary changes across various industries.
答案1·2026年3月19日 23:40