🔬 科学研究工具

🔗 AWG线规转换器Wire Gauge Converter 输入 AWG 美国线规号，换算为公制线径、截面积与每千米电阻，或反向查询，用于线缆选型、载流量评估与电路布线对照。Wire Gauge Converter - convert values online, free and instant. Free online tool on ToolBox — 100% client-side, no data uploaded, no install. Part of the S... 💡 LED限流电阻计算器LED Resistance Calculator 输入电源电压、LED 正向压降与额定工作电流，计算所需串联限流电阻阻值、实际消耗功率，并给出最接近的标准电阻选型建议。LED Resistance Calculator - calculate online, free and accurate. Free online tool on ToolBox — 100% client-side, no data uploaded, no install. Part of the ... 📚 NATO 音标字母Nato Phonetic NATO 音标字母：把文本逐字母转成 Alpha、Bravo、Charlie 拼读。Convert text to the NATO phonetic alphabet (Alpha, Bravo, Charlie…) for clear spelling over radio or phone. Type and copy instantly—client-side, no upload. 🔧 PCB走线宽度计算器Pcb Trace Width 基于 IPC-2221 标准，输入电流、铜厚与允许温升，计算 PCB 铜箔走线所需宽度，用于电路板布线设计，避免过流发热过载。Pcb Trace Width - free online tool. Free online tool on ToolBox — 100% client-side, no data uploaded, no install. Part of the Scientific Research tools. 🎲 Pharmacode 条形码Pharmacode Barcode Pharmacode 条形码：输入 1~131070 的整数，生成药品二进制条码。Generate Pharmacode barcodes from numbers 1–131070 for pharmaceutical packaging. Adjust width and preview—100% client-side, no upload, free online generator. 🧮 P值计算器P Value Calculator 按统计量与自由度计算 P 值并给出显著性水平提示，支持 t、卡方等常见检验，用于统计结果判读，纯前端计算。P Value Calculator - calculate online, free and accurate. Free online tool on ToolBox — 100% client-side, no data uploaded, no install. Part of the Scienti... ⏱️ RC时间常数 (τ) 计算器RC Time Constant Calculator ⏱️ RC时间常数 (τ) 计算器RC Time Constant Calculator - free online tool. Free online tool on ToolBox — 100% client-side, no data uploaded, no install. Part of the Scientific Resear... 🧮 T分数计算器T Fraction Calculator 输入样本均值、总体均值、标准差与样本量，计算 t 分数，用于小样本下与总体均值的差异检验，结果用于查表判断显著性。T Fraction Calculator - calculate online, free and accurate. Free online tool on ToolBox — 100% client-side, no data uploaded, no install. Part of the Scie... 🧮 Z分数计算器Z Fraction Calculator 输入数值、总体均值与标准差，计算标准分数 Z，衡量该值偏离均值多少标准差，用于成绩标准化、异常检测与统计比较。Compute Z-scores from a value, mean and standard deviation, with the 68-95-99.7 rule. See standard deviations from the mean—free, client-side, instant. 🧮 n 次方根计算器Nth Root Calculator n 次方根计算器：输入底数与根指数 n，计算 n 次方根并展示计算步骤，支持任意正实数开方运算。Nth Root Calculator - calculate online, free and accurate. Free online tool on ToolBox — 100% client-side, no data uploaded, no install. Part of the Scient... 🧮 一元二次方程求解Quadratic Equation Solver 一元二次方程求解器：输入二次项系数 a、b、c，按判别式求实数根（含重根与虚根），并给出求解步骤，用于代数学习与解题验证。Solve quadratic equations (ax^2+bx+c=0) online, step by step. Free online tool on ToolBox — 100% client-side, no data uploaded, no install. Part of the Sci... 🧮 三角函数计算器Trigonometry Calculator 输入正弦、余弦、正切等函数值，计算其反三角函数对应的角度，支持角度制与弧度制切换，用于三角方程求解与几何测量。Trigonometry Calculator - calculate online, free and accurate. Free online tool on ToolBox — 100% client-side, no data uploaded, no install. Part of the Sc... 🧮 中位数计算器Median Calculator 中位数计算器：输入一组数据，自动排序并取中间值，不受极端值影响。Median Calculator - calculate online, free and accurate. Free online tool on ToolBox — 100% client-side, no data uploaded, no install. Part of the Scientif... 🧮 二次方程求解器Quadratic Equation 输入系数 a、b、c，求解一元二次方程 ax² + bx + c = 0 的根，返回实根或复根及判别式，用于代数作业与抛物线交点分析。Quadratic Equation - free online tool. Free online tool on ToolBox — 100% client-side, no data uploaded, no install. Part of the Scientific Research tools. 🔬 交互式元素周期表Cycle 点击元素查看详情，支持按名称/符号/原子序数搜索，按类别着色。内置全部 118 种元素数据。Cycle - free online tool. Free online tool on ToolBox — 100% client-side, no data uploaded, no install. Part of the Scientific Research tools. 🧮 众数计算器Mode Calculator 输入一组数值，找出出现次数最多的众数，可返回一个或多个众数，也能判断无众数情形，用于频数统计、数据分布与教学示例。Mode Calculator - calculate online, free and accurate. Free online tool on ToolBox — 100% client-side, no data uploaded, no install. Part of the Scientific... ⚗️ 元素周期表Periodic Table 展示 118 个化学元素的完整周期表，点击任一元素查看原子序数、符号、原子量、电子排布与物性等详情，用于化学学习与查表。Periodic Table - free online tool. Free online tool on ToolBox — 100% client-side, no data uploaded, no install. Part of the Scientific Research tools. 🧮 公积金计算器Housing Fund Calculator 公积金计算器：输入工资基数与缴存比例，计算个人与单位月缴存额、贷款额度与月供参考，用于住房公积金规划。Calculate housing provident-fund monthly contribution, pooled balance and estimated loan amount and repayment from salary, rates and tenure. Reference—free. ⚗️ 分子量计算器Calc Cycle 输入化学式自动解析元素并计算分子量，支持括号与嵌套，内置全部 118 种元素原子量。Calc Cycle - calculate online, free and accurate. Free online tool on ToolBox — 100% client-side, no data uploaded, no install. Part of the Scientific Rese... 🧮 分数计算器Fraction Calculator 对分数进行加减乘除与约分、通分，支持带分数与小数互转，适合数学作业校对，纯前端计算即时出结果。Fraction Calculator - calculate online, free and accurate. Free online tool on ToolBox — 100% client-side, no data uploaded, no install. Part of the Scient... ⚛️ 功 W = F·d·cosθWork Done 由力的大小、位移与夹角，按 W = F·d·cosθ 计算恒力所做的功。Work Done - free online tool. Free online tool on ToolBox — 100% client-side, no data uploaded, no install. Part of the Scientific Research tools. ⚛️ 功率 P = F·vMechanical Power Calculator 输入作用力与同向速度，按 P = F·v 计算机械功率（瓦特）并支持单位换算，用于力学做功、传送带与电机出力估算。Mechanical Power Calculator - free online tool. Free online tool on ToolBox — 100% client-side, no data uploaded, no install. Part of the Scientific Resear... ⚛️ 动能 E_kKinetic Energy Calculator 输入物体的质量与速度，按 E_k = ½mv² 计算平动动能（焦耳）并支持单位换算，用于力学作业、碰撞分析与运动能量估算。Kinetic Energy Calculator - free online tool. Free online tool on ToolBox — 100% client-side, no data uploaded, no install. Part of the Scientific Research... ⚛️ 化学式摩尔质量计算器Molar Mass Calculator 输入化学式计算摩尔质量（如H2O、NaCl、C6H12O6、H2SO4）Molar Mass Calculator - calculate online, free and accurate. Free online tool on ToolBox — 100% client-side, no data uploaded, no install. Part of the Scie... ⚗️ 化学方程式配平器Equation Balancer 输入未配平的化学方程式，自动求解最小整数化学计量数并验证原子守恒。支持括号 Ca(OH)₂、水合物 CuSO₄·5H₂O。Equation Balancer - free online tool. Free online tool on ToolBox — 100% client-side, no data uploaded, no install. Part of the Scientific Research tools. 🧪 化学计算器Chemistry Calculator 输入化学式（支持括号如 Ca(OH)₂），计算分子摩尔质量，并可求解溶液浓度、pH 值与理想气体状态方程，适合化学学习与实验配液。Chemistry Calculator - calculate online, free and accurate. Free online tool on ToolBox — 100% client-side, no data uploaded, no install. Part of the Scien... 🧮 单因素方差分析（ANOVA）Variance Analysis ( ANOVA ) Calculator 单因素方差分析（ANOVA）计算器：输入多组样本数据，计算组间/组内平方和、F 值与显著性，判断多组均值是否存在显著差异。Variance Analysis ( ANOVA ) Calculator - calculate online, free and accurate. Free online tool on ToolBox — 100% client-side, no data uploaded, no install.... ⚛️ 单摆周期 TPendulum Period Calculator 由摆长与重力加速度，按 T = 2π√(L/g) 计算小角度单摆周期。Pendulum Period Calculator - free online tool. Free online tool on ToolBox — 100% client-side, no data uploaded, no install. Part of the Scientific Researc... 🧮 卡方计算器Chi Square Calculator 输入观察频数与期望频数计算卡方值与自由度，并给出显著性提示，用于分类变量独立性检验，纯前端计算。Chi Square Calculator - calculate online, free and accurate. Free online tool on ToolBox — 100% client-side, no data uploaded, no install. Part of the Scie... 🌡️ 压力单位转换器Pressure Converter 输入压力数值，在帕斯卡、巴、PSI、标准大气压、毫米汞柱等单位间换算，用于工程、气象与医疗场景下的压力单位转换。Pressure Converter - convert values online, free and instant. Free online tool on ToolBox — 100% client-side, no data uploaded, no install. Part of the Sci... 🌈 可见光波长转RGB颜色Wavelength to RGB 输入 380-780nm 可见光波长，转换为对应的 RGB 颜色值及近似色名，用于光谱可视化、LED 配色与光学演示中的颜色映射。Wavelength to RGB - convert values online, free and instant. Free online tool on ToolBox — 100% client-side, no data uploaded, no install. Part of the Scie... ⚛️ 向心力 F_cCentripetal Force 由质量、线速度与曲率半径，按 F = mv²/r 计算匀速圆周运动所需向心力。Centripetal Force - free online tool. Free online tool on ToolBox — 100% client-side, no data uploaded, no install. Part of the Scientific Research tools. ➡️ 向量计算器Vector Calculator 向量计算器：支持二维/三维向量的加减、点积、叉积、模长与夹角运算，并可可视化展示向量关系，用于线性代数与物理计算。Vector Calculator - calculate online, free and accurate. Free online tool on ToolBox — 100% client-side, no data uploaded, no install. Part of the Scientif... 🧮 四分位数计算器Quartile Calculator 输入一组数值，计算第一、第二（中位数）、第三四分位数及四分位距 IQR，用于数据分布描述、箱线图绘制与异常值筛查。Quartile Calculator - calculate online, free and accurate. Free online tool on ToolBox — 100% client-side, no data uploaded, no install. Part of the Scient... 📏 国际单位(SI)转换器SI Unit Converter 国际单位（SI）转换器：覆盖 7 个 SI 基本量、词头（千/毫/微等）与导出单位换算，用于物理量单位统一与科学记数法转换。SI Unit Converter - convert values online, free and instant. Free online tool on ToolBox — 100% client-side, no data uploaded, no install. Part of the Scie... 🧮 圆周率 π 位数查询Pi Digits 圆周率 π 位数查询工具：输入位数 N 展示圆周率 π 的前 N 位小数，用于数学演示、精度测试与教学查阅。Pi Digits - free online tool. Free online tool on ToolBox — 100% client-side, no data uploaded, no install. Part of the Scientific Research tools. 🌍 地理距离计算器Geography Distance Calculator 基于 Haversine 公式计算两点间大圆距离，支持方位角计算与地图可视化Geography Distance Calculator - calculate online, free and accurate. Free online tool on ToolBox — 100% client-side, no data uploaded, no install. Part of ... 🧭 地理距离计算（经纬度）Calc Distance 基于 Haversine 公式计算地球表面两点间的大圆距离，支持十进制度与度分秒输入Calc Distance - calculate online, free and accurate. Free online tool on ToolBox — 100% client-side, no data uploaded, no install. Part of the Scientific R... ✅ 墨西哥 RFC 验证Rfc Validator 墨西哥 RFC 验证工具：输入墨西哥纳税人登记号（RFC），校验格式、长度与校验位合法性，用于跨境身份与税号核验。Rfc Validator - check and validate online, free. Free online tool on ToolBox — 100% client-side, no data uploaded, no install. Part of the Scientific Resea... ⚛️ 声波多普勒频移Doppler Effect 由波速、源频率、观察者速度与波源速度，按 f' = f(v+v_o)/(v-v_s) 计算接近时的观测频率。Doppler Effect - free online tool. Free online tool on ToolBox — 100% client-side, no data uploaded, no install. Part of the Scientific Research tools. 🌌 天文地理计算器Astronomy Geography Calculator 🌌 天文地理计算器Astronomy Geography Calculator - calculate online, free and accurate. Free online tool on ToolBox — 100% client-side, no data uploaded, no install. Part of... 🔭 天文观测工具箱Astronomy Toolkit 月相查询 / 星等亮度对比 / 陨石撞击坑估算 / 经纬度与UTM转换 / 极昼极夜判断 / 观测条件评估Astronomy Toolkit - free online tool. Free online tool on ToolBox — 100% client-side, no data uploaded, no install. Part of the Scientific Research tools. ⚛️ 密度 ρ = m/VDensity Calculator 输入物质的质量与体积，按 ρ = m/V 计算密度（如 g/cm³ 或 kg/m³）并可切换单位，用于材料识别、浮力判断与实验测量。Density Calculator - free online tool. Free online tool on ToolBox — 100% client-side, no data uploaded, no install. Part of the Scientific Research tools. 🧱 密度/质量/体积换算Density / Mass / Volume Converter 输入密度、质量、体积中的任意两个量，按公式 ρ=m/V 自动计算第三个量，方便物质密度与质量体积的相互换算。Convert density, mass and volume (rho = m / V). Free online tool on ToolBox — 100% client-side, no data uploaded, no install. Part of the Scientific Resear... 🎲 密码短语生成器Passphrase Generator 密码短语在线生成器，从词库随机抽取多词组成易记高熵密码短语，可设词数与分隔符，适合账户安全，数据本地生成不上传，纯前端。Passphrase Generator - generate results online, free and instant. Free online tool on ToolBox — 100% client-side, no data uploaded, no install. Part of the... 🧮 对数计算器Logarithm Calculator 输入底数与真数，计算常用对数 log₁₀、自然对数 ln 及任意底 logₙ(x)，支持换底运算，用于对数缩放、分贝换算与科学计算。Logarithm Calculator - calculate online, free and accurate. Free online tool on ToolBox — 100% client-side, no data uploaded, no install. Part of the Scien... 🧮 幂计算器Power Calculator 幂计算器：输入底数与指数，计算 base^exponent 幂运算结果，支持正负数与小数指数，用于数学与工程计算。Power Calculator - calculate online, free and accurate. Free online tool on ToolBox — 100% client-side, no data uploaded, no install. Part of the Scientifi... 🧮 平均数计算器Mean Calculator 平均数计算器：输入数值集合，计算算术平均、几何平均与调和平均三种平均值，适用于统计与科学数据分析。Mean Calculator - calculate online, free and accurate. Free online tool on ToolBox — 100% client-side, no data uploaded, no install. Part of the Scientific... 🧮 平方根计算器Root Calculator 平方根计算器：计算 √x 主平方根，并对负数返回虚数结果，支持实数与复数根式运算，用于数学计算。Root Calculator - calculate online, free and accurate. Free online tool on ToolBox — 100% client-side, no data uploaded, no install. Part of the Scientific... ⚛️ 库仑定律Coulomb Force Calculator 由两电荷量与距离，按 F = k·q₁q₂/r²（k=8.988×10⁹）计算真空中两点电荷间静电力大小。Coulomb Force Calculator - free online tool. Free online tool on ToolBox — 100% client-side, no data uploaded, no install. Part of the Scientific Research ... 🔩 扭矩单位转换器Torque Converter 输入扭矩数值，在牛·米、磅·英尺、千克力·米等单位间换算，用于机械、汽车与工业设备中选型对照与力矩单位转换。Torque Converter - convert values online, free and instant. Free online tool on ToolBox — 100% client-side, no data uploaded, no install. Part of the Scien... 🧮 指数计算器Exponent Calculator 指数计算器：输入实数 x 计算 eˣ，并支持常用指数函数（如 aˣ、e^{kx}）运算，用于数学与科学计算。Exponent Calculator - calculate online, free and accurate. Free online tool on ToolBox — 100% client-side, no data uploaded, no install. Part of the Scient... 🧮 排列数 P(n, r)Permutation Calculator 从 n 个不同元素中取 r 个的排列数：P(n,r) = n! / (n−r)!Permutation Calculator - calculate online, free and accurate. Free online tool on ToolBox — 100% client-side, no data uploaded, no install. Part of the Sci... 📝 提取电话号码Extract Phone Number 粘贴一段文本，自动提取其中出现的电话号码（手机与固话），按行列出便于复制整理，用于从通讯录、日志或文档中批量抽取号码。Extract Phone Number - free online tool. Free online tool on ToolBox — 100% client-side, no data uploaded, no install. Part of the Scientific Research tools. 🧮 效应量计算器Effect Size Calculator 输入两组样本的均值、标准差与样本量，计算 Cohen's d 等效应量，衡量实验处理效果的统计学意义，用于论文写作与社科研究。Effect Size Calculator - calculate online, free and accurate. Free online tool on ToolBox — 100% client-side, no data uploaded, no install. Part of the Sci... 🧮 斐波那契数列工具Fibonacci 斐波那契数列工具：生成指定项数的斐波那契数列，展示相邻项比值趋近黄金分割比 φ 的特性，用于数学教学与序列分析。Fibonacci - free online tool. Free online tool on ToolBox — 100% client-side, no data uploaded, no install. Part of the Scientific Research tools. ⚛️ 斜抛射程与最大高度Projectile Range 由初速度与抛射角，按 R=v²sin(2θ)/g、H=v²sin²θ/(2g) 计算水平射程与最大高度。Projectile Range - free online tool. Free online tool on ToolBox — 100% client-side, no data uploaded, no install. Part of the Scientific Research tools. 🧮 方差计算器Variance Calculator 计算样本或总体方差与标准差，输入数据集即得离散程度，用于统计作业与数据质量分析，纯前端即时计算。Variance Calculator - calculate online, free and accurate. Free online tool on ToolBox — 100% client-side, no data uploaded, no install. Part of the Scient... ⭐ 星等亮度对比Star Magnitude Compare 输入两个星等数值计算亮度比，或从内置恒星表中选择对象对比，按星等差每 5 等约 100 倍的规律换算视亮度，用于天文科普。Star Magnitude Compare - compare online, free and clear. Free online tool on ToolBox — 100% client-side, no data uploaded, no install. Part of the Scientif... 🧮 最大公约数（GCD）Gcd Calculator 输入两个或多个整数，用欧几里得算法求它们的最大公约数，用于分数约分、周期同步与数论问题，支持多数值一次性批量求解。Gcd Calculator - calculate online, free and accurate. Free online tool on ToolBox — 100% client-side, no data uploaded, no install. Part of the Scientific ... 🧮 最小公倍数（LCM）Lcm Calculator 利用 LCM(a,b)=|a·b|/GCD(a,b)，输入若干正整数计算它们的最小公倍数，适用于通分、周期对齐等数学计算场景。Lcm Calculator - calculate online, free and accurate. Free online tool on ToolBox — 100% client-side, no data uploaded, no install. Part of the Scientific ... 🔢 有效数字计算器Significant Figures 有效数字计算器Significant Figures - free online tool. Free online tool on ToolBox — 100% client-side, no data uploaded, no install. Part of the Scientific Research tools. 🧮 极差计算器Range Calculator 输入一组数据计算最大值与最小值之差（极差），并附简单统计，用于数据离散程度初探，纯前端即时统计。Range Calculator - calculate online, free and accurate. Free online tool on ToolBox — 100% client-side, no data uploaded, no install. Part of the Scientifi... 🌅 极昼极夜日期判断Polar Day Night 输入纬度，计算该纬度出现极昼与极夜的起止日期、持续时间及全年光照分布信息，用于地理与天文现象查询。Polar Day Night - free online tool. Free online tool on ToolBox — 100% client-side, no data uploaded, no install. Part of the Scientific Research tools. 🧮 样本量计算器Sample Size Calculator 样本量计算器：设定置信水平与误差范围，反推调查或实验需要多少个样本。Compute survey sample size from population, confidence level, margin of error and expected proportion. Step-by-step math for research—free, client-side. 🎲 概率计算器Probability Calculator 概率计算器：计算常见离散与连续概率分布的事件发生概率并可视化分布曲线，辅助统计学习与风险评估。Probability Calculator - calculate online, free and accurate. Free online tool on ToolBox — 100% client-side, no data uploaded, no install. Part of the Sci... ⚡ 欧姆定律计算器Ohms Law Calculator 输入电压、电流与电阻中的任意两个已知量，按 V = I×R 求解第三个未知量，并可计算电功率 P = VI，用于基础电路设计与电池供电分析。Ohms Law Calculator - calculate online, free and accurate. Free online tool on ToolBox — 100% client-side, no data uploaded, no install. Part of the Scient... 🌊 潮汐高度估算Tide Height Estimator 基于月球引力模型，输入日期、月相与纬度估算理论潮汐高度，为近海活动、养殖与观潮提供潮汐参考。Tide Height Estimator - free online tool. Free online tool on ToolBox — 100% client-side, no data uploaded, no install. Part of the Scientific Research tools. 🔥 热传递计算器Heat Transfer Calculator 输入温度差、比热容、质量或传热系数，按 Q=mcΔT 计算传导、对流与辐射的热量传递，用于热力学作业与散热设计估算。Heat Transfer Calculator - calculate online, free and accurate. Free online tool on ToolBox — 100% client-side, no data uploaded, no install. Part of the S... ⚛️ 牛顿第二定律 F = maNewtons Second 输入物体质量与加速度，按 F = ma 计算所受合外力（牛顿）并支持单位换算，用于力学作业、推力估算与受力分析。Newtons Second - free online tool. Free online tool on ToolBox — 100% client-side, no data uploaded, no install. Part of the Scientific Research tools. 🧮 物理单位换算（力、功、功率等）Physics Unit Convert 在牛顿、焦耳、瓦特等力、功、功率单位间换算，处理常用前缀，用于物理作业与工程估算，纯前端即时换算。Physics Unit Convert - convert values online, free and instant. Free online tool on ToolBox — 100% client-side, no data uploaded, no install. Part of the S... ⚛️ 物理计算器Physics Calculator 物理计算器：选定公式后填入已知变量，自动解出未知量。Solve common physics formulas—kinematics, force, energy, electricity—with a built-in constants table. Enter variables, get results instantly—free, browser-only. 🧪 理想气体状态方程Ideal Gas Law Calculator (PV = nRT) 输入任意三个已知量，求解第四个未知量。R = 8.314 J/(mol·K)。Compute pressure, volume, temperature or moles of an ideal gas. Free online tool on ToolBox — 100% client-side, no data uploaded, no install. Part of the S... ⚛️ 电场强度 EElectric Field Point 由点电荷与距离，按 E = k·q/r²（k=8.988×10⁹）计算真空中该点电场强度。Electric Field Point - free online tool. Free online tool on ToolBox — 100% client-side, no data uploaded, no install. Part of the Scientific Research tools. 🔋 电池续航时间计算器Battery Life Calculator 电池续航时间计算器：根据电池容量（mAh/Ah）、负载电流或功率与效率，估算设备持续工作时间（小时），用于电源选型与续航评估。Battery Life Calculator - calculate online, free and accurate. Free online tool on ToolBox — 100% client-side, no data uploaded, no install. Part of the Sc... 🎲 电话二维码Phone QR 将电话号码生成为可拨号的二维码，扫码即发起呼叫，适合名片与海报，纯前端生成不上传任何数据。Phone QR - free online tool. Free online tool on ToolBox — 100% client-side, no data uploaded, no install. Part of the Scientific Research tools. 📚 电话号码查询Phone Lookup 输入电话号码，查询其号段、归属地区与运营商信息（基于内置号段数据），用于快速识别来电归属地，结果在本地浏览器内处理。Phone Lookup - free online tool. Free online tool on ToolBox — 100% client-side, no data uploaded, no install. Part of the Scientific Research tools. 🔌 电阻分压器计算器Voltage Divider Calculator 输入输入电压与两个串联电阻阻值，计算分压电路的输出电压，用于传感器偏置、电平转换与参考电压设计，支持单位换算。Voltage Divider Calculator - calculate online, free and accurate. Free online tool on ToolBox — 100% client-side, no data uploaded, no install. Part of the... 🎨 电阻色码解码器Resistor Color Code 电阻色码解码器：读取四环/五环电阻色环颜色，按色码表换算标称阻值与误差，并支持反向由阻值查色环，适合电子爱好者速查。Resistor Color Code - free online tool. Free online tool on ToolBox — 100% client-side, no data uploaded, no install. Part of the Scientific Research tools. 🧮 百分位数计算器Percentile Calculator 输入数据集合与目标百分位（0-100），计算对应的百分位数数值，用于成绩排名、生长曲线与统计分位分析，说明数据所处位置。Percentile Calculator - calculate online, free and accurate. Free online tool on ToolBox — 100% client-side, no data uploaded, no install. Part of the Scie... 🧮 相关系数计算器Correlation Calculator 输入成对的 X 与 Y 两组数据（个数须相等），计算皮尔逊相关系数，量化两组变量间的线性相关方向与强弱，用于实验数据分析与统计检验。Correlation Calculator - calculate online, free and accurate. Free online tool on ToolBox — 100% client-side, no data uploaded, no install. Part of the Sci... 🔢 矩阵计算器Matrix Calculator 输入一个或多个矩阵，进行加减乘、转置、求行列式、逆矩阵、秩与幂运算，用于线性代数作业、方程组求解与计算机图形变换。Matrix Calculator - calculate online, free and accurate. Free online tool on ToolBox — 100% client-side, no data uploaded, no install. Part of the Scientif... 🧮 科学计算器Science Calculator 提供四则、幂、对数、三角函数等科学运算，支持括号与历史，适合学习作业与工程速算，纯前端运行无需安装。Science Calculator - calculate online, free and accurate. Free online tool on ToolBox — 100% client-side, no data uploaded, no install. Part of the Scienti... ⚛️ 简谐振动周期 TSpring Oscillation Period 输入振子质量与弹簧刚度，按简谐振动周期公式 T=2π√(m/k) 计算弹簧振子的振动周期，用于物理教学与实验。Spring Oscillation Period - free online tool. Free online tool on ToolBox — 100% client-side, no data uploaded, no install. Part of the Scientific Research... 💧 管道流量计算器Flow Calculator 输入管道截面积（或管径）与流体流速，按 Q = A×v 计算体积流量，或输入容器体积与充满时间求平均流量，用于给排水与化工估算。Flow Calculator - free online tool. Free online tool on ToolBox — 100% client-side, no data uploaded, no install. Part of the Scientific Research tools. 🧮 素数工具Prime 素数在线工具，判断整数是否为素数，或生成指定范围内的素数表、求质因数分解，适合数论学习与编程验证，纯前端运行。Prime - free online tool. Free online tool on ToolBox — 100% client-side, no data uploaded, no install. Part of the Scientific Research tools. 🧮 线性方程组求解（2元/3元）Xianxingfangchengzuqiujie 2yuan 3yuan 线性方程组求解器（2元/3元）：输入二元或三元一次方程组的系数，按克莱姆法则或消元法求解未知数，用于代数与工程计算。Xianxingfangchengzuqiujie 2yuan 3yuan - free online tool. Free online tool on ToolBox — 100% client-side, no data uploaded, no install. Part of the Scienti... ✅ 组合数 C(n, r)Combination Calculator 从 n 个不同元素中取 r 个的组合数：C(n,r) = n! / (r!·(n−r)!)Combination Calculator - calculate online, free and accurate. Free online tool on ToolBox — 100% client-side, no data uploaded, no install. Part of the Sci... 📍 经纬度与UTM坐标转换Latlon Utm Converter 基于 WGS84 椭球体，在经纬度（WGS84）与 UTM 平面直角坐标之间互转，用于地图定位与测绘坐标转换。Latlon Utm Converter - convert values online, free and instant. Free online tool on ToolBox — 100% client-side, no data uploaded, no install. Part of the S... 🧮 统计学计算（均值、方差、标准差）Calc Stats 统计描述计算器：输入数据集，计算算术均值、方差与标准差等描述统计量，辅助科研数据汇总与离散程度分析。Calc Stats - calculate online, free and accurate. Free online tool on ToolBox — 100% client-side, no data uploaded, no install. Part of the Scientific Rese... 📊 统计计算器Statistics Calculator 统计计算器：计算描述统计量、频数分布并绘制直方图可视化，支持样本方差等推断统计，用于数据分析与教学。Statistics Calculator - calculate online, free and accurate. Free online tool on ToolBox — 100% client-side, no data uploaded, no install. Part of the Scie... ⚛️ 胡克定律 F = kxHookes Law 输入弹簧刚度系数与形变量，按胡克定律 F=kx 计算弹簧的恢复力（弹性力），适用于弹簧受力分析与机械设计。Hookes Law - free online tool. Free online tool on ToolBox — 100% client-side, no data uploaded, no install. Part of the Scientific Research tools. 🍎 自由落体运动计算Free Fall Motion Calculator 输入下落高度、初速度与重力加速度，计算物体自由下落的落地时间与落地末速度，适用于物理课堂演示与抛体运动实验估算。Solve free-fall time, velocity and distance under gravity. Free online tool on ToolBox — 100% client-side, no data uploaded, no install. Part of the Scient... 🚗 速度/距离/时间计算Speed / Distance / Time Calculator 输入速度、距离、时间中的任意两个已知量，自动求解第三个量，适用于匀速直线运动的路程与时间估算。Compute speed, distance or time in kinematics. Free online tool on ToolBox — 100% client-side, no data uploaded, no install. Part of the Scientific Researc... ⚡ 逻辑门模拟器Logic Gate Simulator ⚡ 逻辑门模拟器Logic Gate Simulator - free online tool. Free online tool on ToolBox — 100% client-side, no data uploaded, no install. Part of the Scientific Research tools. ⚗️ 酸碱pH值计算器pHCalculator 输入氢离子浓度或 pH，按 pH=-log₁₀[H⁺] 计算溶液酸碱度、氢离子浓度与 pOH，用于化学实验与水质酸碱分析。pHCalculator - calculate online, free and accurate. Free online tool on ToolBox — 100% client-side, no data uploaded, no install. Part of the Scientific Re... ⚛️ 重力势能 E_pGravitational Potential Energy Calculator 输入物体质量、重力加速度与高度，按重力势能公式 E_p=mgh 计算物体相对于参考面的重力势能大小。Gravitational Potential Energy Calculator - free online tool. Free online tool on ToolBox — 100% client-side, no data uploaded, no install. Part of the Sci... 🧮 阶乘计算器Factorial Calculator 计算 n! = n × (n−1) × ... × 2 × 1（支持大整数，推荐 n ≤ 10000）Factorial Calculator - calculate online, free and accurate. Free online tool on ToolBox — 100% client-side, no data uploaded, no install. Part of the Scien... ☄️ 陨石撞击坑直径估算Meteor Crater Estimator 输入陨石直径、密度、撞击速度与角度，估算撞击坑直径、释放能量（以 TNT 当量计）及影响范围，用于科普演示与天文教学。Meteor Crater Estimator - free online tool. Free online tool on ToolBox — 100% client-side, no data uploaded, no install. Part of the Scientific Research t...